Introduction

The potential of congenital heart disease to be an epidemic among the adult population is not far-fetched, due to augmented detection from increased awareness and superior diagnostic tools, as well as enhanced survival brought about by better surgical techniques and improved follow-up. The 32nd Bethesda Conference report in 2000 pegged the prevalence of congenital heart disease (CHD) in adults to be approximately 2800 adults per 1 million population, with more than half of them being classified as having lesions with moderate or high complexity.1

As stated in the 2010 European Society of Cardiology Guidelines for the management of grown-up congenital heart disease, these groups of adults particularly require specialist care.2 More alarming is the recent observation that most deaths from congenital heart disease now occur in adults.3 Among the congenital heart diseases that benefit from such specialist care are those that involve shunt anomalies, such as interatrial septal defect, ventricular septal defect and patent ductus arteriosus. Such anomalies can be missed by standard transthoracic echocardiography and are usually confirmed through contrast echocardiography, a specialized procedure that requires technical expertise and supervision by a cardiologist with advanced echo training. However, the maldistribution or lack of echo specialists in certain countries deprives many patients from obtaining such procedures, and probably contributes to delayed diagnosis and treatment.

The recent surge in interest as well as volume of cases seen in developing regions of the world therefore presents a dilemma in scenarios wherein subspecialty expertise is not readily available for purposes of clinical or echocardiographic diagnosis and, ultimately, directed care and definitive treatment. Such early detection is particularly crucial, since a delayed or missed diagnosis can deprive the patient of early specialist referral, timely surgical intervention, and holistic management. In archipelagic situations such as the Philippines, the issue of inequality of access to specialist care is undeniably relevant, especially in the background of a long-standing imbalance in supply and demand for specialist care in rural communities and far-fl ung areas of the country.

Among the numerous strategies employed by governments to address this imbalance, telemedicine appears to provide a viable option. The emerging utility of medical software and technology to augment current strategies for patient and healthcare-related activities cannot be ignored in an era of mobile health and telemedicine. Aside from point-of care diagnosis and treatment offered by mobile computing devices and smartphone handsets, new-generation technologies have inevitably started to penetrate the healthcare industry through their capacity to mediate a variety of services conducted on a long-distance basis.

Based on the reported image quality and data security, current video calling software may find utility in telemedicine through point-of-care diagnosis by echocardiographic specialists. This study is intended to determine whether the use of remote imaging using the FaceTime technology of Apple, Inc. for delivery and subsequent interpretation of echocardiographic videos will generate echocardiographic diagnoses that are comparable to those made on an onsite basis, particularly when dealing with suspected cardiac shunt anomalies subjected to contrast echocardiography.

Research Question

Are onsite interpretations of contrast echocardiograms of suspected cardiac shunt anomalies made by echo specialists comparable to their offsite readings made via the real-time videoconferencing technology of FaceTime?

Null Hypothesis

Onsite interpretations of contrast echocardiograms of suspected cardiac structural or shunt anomalies made by echo specialists are not comparable to their offsite readings made via the real-time videoconferencing technology of FaceTime.

Alternate Hypothesis

Onsite interpretations of contrast echocardiograms of suspected cardiac shunt anomalies made by echo specialists are comparable to their offsite readings made via the realtime videoconferencing technology of FaceTime.

Objectives

General Objective

• To determine and compare the onsite diagnosis of contrast echocardiograms of suspected cardiac structural or shunt anomalies made by echo specialists to their offsite readings made via the real-time videoconferencing technology of FaceTime

Specific Objectives

• To determine the concordance of the onsite and offsite echo diagnoses with respect to specific echocardiographic parameters: 1) chamber and great vessel size, 2) presence or absence of structural defect or shunt anomaly based on 2-dimensional echo, 3) presence or absence of structural defect or shunt anomaly based on color Doppler study, and 4) presence or absence of structural defect or shunt anomaly based on contrast echocardiography

• To assess the technical aspects of the videoconferencing session, with respect to objective (lag time to image transmission, upload and download speeds) and subjective (video and audio quality scores) parameters

Significance of the Study

The evaluation of innovative strategies for effective and timely delivery of medical care will always find relevance in situations where healthcare inequalities abound, whether in terms of maldistribution of resources and opportunities, or lack thereof. The present study primarily derives its significance from the potential for providing a tenable solution to such a dilemma in our local setting. By proving that the diagnosis of suspected structural defects or shunt anomalies is possible via remote imaging contrast echocardiography, this study can address the need for echocardiographic expertise even in areas of the country where the supply of such is very much wanting.

The Philippine Society of Echocardiography, through its vision, “Quality echocardiography by competent professionals for every patient,” best encapsulates what this study hopes to eventually achieve.4 Moreover, the success of this scientific endeavour is perceived to give telehealth advocates and critics alike another look at this arena, either by triggering follow-up research work or initiating modernized policies ultimately intended for improved healthcare especially for the underserved sectors of our society.

Methodology

Trial Design

This cross-sectional study determined whether there is any significant difference between the onsite and offsite interpretations of contrast echocardiograms made by echocardiographers. Instead of a telemedical consultation with real-time echocardiography of an actual patient, a simulation was implemented wherein hypothetical “onsite” and “offsite” venues were set up. Such a set-up obviated the need for actual patient interrogation as well as consent, since only the pre-recorded echo images of the patient (stored in DVD files) were utilized for image transmission.

Randomization and Blinding. No randomization was required in this study, since pre-existing records were reviewed for contrast echocardiograms. All onsite and offsite readers were blinded to patient identity. The outcome assessors and those involved in the data analysis were likewise blinded to patient, original sonographer and echocardiographer identity, transmission details, and clinical diagnosis.

The study was conducted in compliance with the ethical principles set forth in the Declaration of Helsinki as well as the Philippine Heart Center Institutional Ethics Review Board (PHC IERB). Since archived DVD files of previouslycompleted echo studies were used in the study and no contact with any patient were made at any time before, during or after the study, informed consent was difficult and impractical to obtain.

Moreover, the investigator preserved the confidentiality of all patients whose echo videos were included in the study and ensured that the subject’s anonymity was maintained through the following maneuvers: 1) transmitted images were stripped of any information that may trace it back to the patient’s identity, by using an opaque adhesive placed over the echo machine screen to obscure the patient’s name, 2) names of patients were codified and represented by numbers on the study report and data collection forms. For these reasons, the investigator requested for the waiver of informed consent.

Study Setting and Time Frame

The medical records of the Non-invasive Cardiology Division of the Philippine Heart Center were reviewed for all contrast echocardiograms done between January 1, 2011 and December 31, 2012 on adult or grown-up patients suspected to have a congenital heart disease, whether it be a structural or shunt anomaly. The site was chosen based on its yearly patient load and reported census of congenital heart disease, being the main referral center for heart disease in the country.

Subject Selection

Criteria for inclusion of echo studies were as follows: 1) done on adult or grown-up patients ≥ 15 years of age, 2) transthoracic echocardiography performed at the study site by a sonographer trained in adult echocardiography, 3) with contrast study done to rule out a structural or shunt anomaly, and 4) with official report initially read by an adult cardiologist with subspecialty training in echocardiography. The DVD files of the echo images and videos as well as their corresponding official reports were retrieved.

Study Maneuver

Feasibility study. A preliminary feasibility study (see Appendix A) was conducted to assess the technical viability of the planned study design. By simulating a long-distance FaceTime videoconference session, the investigator was able to generate video images of acceptable quality. Moreover, consultation with an information technology and telecommunications expert was done to verify feasibility of the set-up. It was concluded that the element of distance between the onsite and offsite venues would not be the crucial factor in determining quality of transmission, but rather the strength of the internet connection at both ends. Based on the above-mentioned assumptions, a simulated videoconferencing session would be acceptable wherein the two sites are located in the same venue, with each end having access to the Internet. Preliminary testing of the obtained data and collection forms (echocardiographic worksheet) was conducted to ensure acceptability in terms of ease of use, interand intra-rater variability, and reproducibility of information.

Devices required. The study investigators ensured that the transmitting site (onsite venue) and receiving site (offsite venue) were equipped with the following materials to enable live videoconferencing: 1) device capable of FaceTime transmission (iPad2 or iPad3), and 2) a means of internet access (through a pre-existing clinic/hospital WiFi connection, a pocket WiFi device, or built-in Wificapability in the device, via 3rd generation mobile technology, or 3G). The live videoconferencing session was made possible through Apple, Inc.’s FaceTime technology, a software built into the iPad device that allows for free and unlimited videoconferencing capability between two FaceTimeenabled devices anywhere in the world through a simple mobile number or email address connection. Meanwhile, the 3G option brings wireless transmission speeds, which allow full motion video, high-speed internet access and videoconferencing.

Pool of Echo Readers. Two cardiologists with level III training in echocardiography and two cardiologists with ongoing training (affiliated with the Philippine Heart Center Division of Non-invasive Cardiology) were requested to participate in the study as onsite and offsite readers. Level 3 training in adult transthoracic echocardiography entails a minimum of 300 transthoracic (TTE) examinations performed and 750 examinations interpreted within a cumulative duration of 12 months training at a duly-accredited echo center.5 Onsite and offsite readers were blinded to patient identity, echo study ID or actual diagnosis (whether clinical or echocardiographic).

Figure 1.
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Flow diagram of study

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Echo readings for comparison. Only the pre-selected echo studies were assigned to the designated echo readers at pre-set reading dates and times, to adjust to reader availability. The “onsite diagnosis” was provided by the onsite reader as s/he viewed the echo images on a television or echo machine screen as the disc was run in a DVD player by the onsite technician. Meanwhile, the “offsite diagnosis” was provided by the offsite reader as s/he simultaneously viewed the echo images on an iPad device in a separate room or cubicle. Further analysis of diagnostic accuracy of the readings was performed by comparing them to the written diagnosis indicated in the official test reports. Standardized data collection forms for onsite and offsite echo interpretation were accomplished by the readers (Appendix B).

Figure 2.
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Logistical set-up for onsite (A) and offsite (B) venues

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Protocol for Videoconferencing Session. A quasi-experimental approach to videoconferencing was employed wherein prerecorded echo videos were displayed on the television or echo machine screen to simulate an actual echo study. A standard protocol for each videoconferencing session was followed (see Figure 1). Once a particular echo study was deemed eligible for inclusion and a date and time has been set for the FaceTime session, the echo technician set up the “onsite” venue by performing the following maneuvers: 1) inserting the disc in the DVD player, 2) ensuring anonymization of echo study by placing an opaque adhesive on the screen to hide any identifying data, 3) ensuring that the onsite reader has an unobstructed view of the screen, and 4) setting up the iPad device in front of the screen. Meanwhile, the offsite reader was stationed at a separate room or cubicle located also within the confines of the echo laboratory of the Philippine Heart Center, and provided with an iPad device to enable him to view the images as they were played by the technician at the onsite area (Figure 2).

The next step was for the onsite technician or onsite reader to initiate contact with the offsite reader by calling the latter’s mobile phone or sending him a SMS, signifying the intent to conduct a FaceTime session. Once the offsite reader acknowledged his availability for the session, the onsite technician initiated a FaceTime call by dialing the offsite iPad contact number or email address. Once the FaceTime call was accepted, both parties were able to see and hear each other in real time. The live video feed, made possible through the FaceTime software, simulated a videoconferencing consultation, with either reader being allowed to give verbal commands to the technician to freeze, rewind or fast-forward the video clips. The onsite and offsite reader were allowed to communicate with each other, but were instructed not to divulge their own diagnosis to the other party. The same amount of clinical information, whether patient-related (age, sex, height, weight, indication for contrast study) or echocardiographic (actual measurements) will be made available by the technician to both readers. However, only the technician had access to the actual patient identity and the officially signed-out echocardiographic diagnosis.

After completion of the study transmission, both onsite and offsite parties conducted a speedtest before disconnecting their device from the internet connection. The internet connection strength and speed at both ends of the transaction was tested through the use of a free internet application named Speedtest.net, which was downloaded to the iPad devices at the start of the study. The readers also assessed the technical aspects of the videoconferencing session, in terms audio and video quality, using a scoring scale of 1 to 4, with 4 being the highest possible score.

Clinical information obtained. Basic patient demographic (age, sex) and clinical data (height, weight, and indication for contrast echocardiography) were obtained by designated personnel based on existing patient records. Informed consent was waived by the investigators (see section on Trial Design).

Method of data abstraction. All readers were instructed to fill up standardized data collection forms for echo interpretation (Appendix B). These worksheets contained general clinical (age, sex, anthropometric data) and session information (session ID, onsite tech ID, onsite and offsite reader ID, date and time of session). Each offsite reader was also provided with a supplementary worksheet which refl ected their evaluation of the technical aspects of the videoconferencing transaction (Appendix C), such as internet speeds and audio/ video quality assessment. An inventory of all FaceTime sessions was kept by designated study personnel for tracking and cross-referencing purposes.

Definition of Outcomes

The concordance between the onsite and offsite echocardiographic interpretation was compared with respect to pre-specified echo parameters which include: chamber and great vessel size, presence or absence of structural defect or abnormality on plain 2-dimensional echocardiography (e.g. drop-out space, abnormal tract, etc.), presence or absence of abnormal mosaic color flow on color Doppler indicating a shunt anomaly, and presence or absence of abnormal contrast pattern on contrast echocardiography (e.g. positive contrast effect, negative contrast effect, premature opacification of a particular chamber).

Measures of concordance included 1) overall agreement rate, computed as the percentage of total possible data points (number of echo paramaters multiplied by the number of FaceTime sessions conducted) with congruent readings, as well as 2) individual kappa coefficients for the 22 pre-specified echo parameters. Accuracy of onsite and offsite diagnoses (pre- and post-contrast) was likewise reported, by comparing them to the official test reports, which served as the reference standard. The impact of contrast echocardiography on diagnosis was then assessed by comparing the accuracy rates of pre-contrast and postcontrast diagnoses. Reading discrepancies were also categorized based on their presumed clinical impact or significance (See Appendix D).

Technical quality of the video conferencing session was determined by obtaining the following: 1) lag time to transmission or PING, reported in milliseconds, 2) upload and download speeds, reported in Megabytes per second, and 3) subjective assessment of transmission quality (video and audio), reported on a subjective scoring scale of 1 to 4, with 4 being the highest possible score.

Data Analysis and Statistical Methods

Sample size computation. The sample size computation was based on previous literature6 which showed a 78% prevalence of cardiac abnormalities among patients subjected to standard 2-dimensional echocardiography. Sixty-six (66) adult echo studies were targeted for this study, which will provide 80% statistical power based on an anticipated effect size (Cohen’s d) of 78% and confidence level of 95%.

Analysis of discrepancy in interpretation. The onsite and offsite echocardiographic readings of each FaceTime session were compared for discrepancies in interpretation in the pre-specified echo parameters as well as in the final diagnosis. The FaceTime sessions were then classified by the investigators into one of three categories based on the potential clinical importance of the discrepancies: Category A – echo readings with no discrepancy, Category B – echo readings with discrepancy of minor clinical significance, Category C – echo readings with discrepancies of intermediate clinical significance, and Category D – echo readings with discrepancies of major clinical significance (Appendix D). In situations wherein more than one discrepancy was identified, the most significant error defined the category designation. The classification was conceptualized by the investigators and agreed upon by a panel of experts from the field of non-invasive cardiology.

Statistical tools and reporting of data. Baseline parameters were reported as means ± standard deviation, or as percentages of the sample population. Classification of discrepancy category was reported as frequencies and percentages of the total sample. Concordance of interpretations was also represented as overall agreement rate (number of congruent interpretations divided by the total number of interpretations made) as well as the Kappa coeffi cients for each echo parameter. Accuracy rates were reported as percentages.

Intra-rater Variability. To test for intra-rater variability of offsite readers, selected echo studies were shown more than once to their respective readers during different session dates, without their knowledge of the echo study ID or previously-made diagnosis. Variability of interpretation was represented as overall agreement rate, computed as the percentage of total possible data points (number of echo paramaters multiplied by the number of FaceTime sessions conducted) with congruent readings.

Results

Baseline characteristics

A total of 68 videoconferencing sessions were included in the study. The mean age of patients was 37 ± 14 years, with a range of 16 to 72 years. More than one-third (37%) of patients were above 40 years. There were more females (62%) than males. The mean body mass index was 23 '± 4 kg/m2, with majority (59%) having indices falling within the 18.5 to 24.9 kg/m2 range. One-third of the patients (32%) had severe pulmonary hypertension as documented by transthoracic echocardiography. Half of the 68 sessions were officially reported to have structural anomalies, while 26% were signed out to have only a suspicion of an anomaly, warranting further investigation (Table 1). The remaining 25% had no anomalies. Table 1 summarizes the baseline characteristics of the patients included in the study.

Table 1. Baseline characteristics of patients in the study (N=68)
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Two certified echocardiographers (level III) and two echocardiographers-in-training (future level III) comprised the pool of readers for the study, all with extensive experience in echocardiographic interpretation, having more than 40 years of combined echo readership under their names. Only two echocardiographers per session were requested to serve as readers. One reader was assigned at the onsite and the other assigned to the offsite venue. All readers were shown to have good intrarater reliability. All the echocardiographic technicians, whether serving as original sonographers or as onsite technicians for the study, were certified medical technologists of the Philippine Heart Center with training in adult transthoracic echocardiography, having an average of more than 3 years active practice in cardiac sonography. All 68 echo studies were conducted with echo machines manufactured by Philips, Inc (IE33 or HD11 models). Table 2 summarizes the baseline technical characteristics of the study.

Table 2. Baseline characteristics of echo readers, technicians, and echo machines
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Comparison of onsite and offsite echocardiographic readings

The onsite and offsite readings were compared with respect to 22 pre-defined echocardiographic parameters. Of the 1496 possible data points for comparison, 1333 of these had identical readings, resulting in an overall agreement rate of 89%. Table 3 shows the agreement rate according to aspect of echo reading: 90% (chamber and vessel size assessment), 92% (detection of defect on plain 2D echo), 90% (detection of defect on color Doppler), 86% (detection of defect on contrast echo, and 84% (final echo diagnosis).

Table 3. Agreement rates according to aspect of echocardiographic readings
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Table 4 shows the proportion of FaceTime sessions with discrepant readings, according to the 22 pre-specified echo parameters. Most discrepancies arose from assessment of LV size (16.2%), coronary sinus size (23.5%) and atrial septal defect on plain 2D (20.6%). The pre-contrast impression differed between the onsite and offsite readers in 23 of 68 sessions (33.8%). Likewise, the onsite and offsite readers had disagreement in terms of overall detection of abnormal contrast pattern in 11 of 68 sessions (16.2%). There were more discrepancies in interpretation and detection of negative contrast effect (15 of 68) than negative contrast effect (12 of 68). However, none were noted in detection of coronary sinus opacification with contrast. The final diagnosis differed in only eleven (16.2%) sessions, mostly dealing with detecion of PFO, ASD or PDA.

Table 4. Proportion of FaceTime sessions with discrepant readings according to specific echo parameter (N=68)
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To further assess the concordance of readings, kappa coefficients were computed for each echo parameter. The videoconferencing sessions demonstrated fairly good concordance in the onsite and offsite readings, with kappa coefficients of more than 0.60 in 14 of 22 echocardiographic parameters (Table 5). Maximum concordance (kappa = 1.00) was obtained in the assessment of premature coronary sinus opacification. Good to excellent concordance (kappa = 0.81 to <1.00) was noted for assessment of almost all chambers (except for the aorta, K=0.49), assessment of ASD type (0.81) and presence on color Doppler (0.75), VSD type (0.66), PDA presence on color Doppler (0.66), presence of abnormal contrast pattern (0.68) and positive contrast effect (0.65), as well as post-contrast impression (0.71) and final echocardiographic diagnosis (0.73). Fair concordance was noted in the assessment VSD on plain 2D (0.26). The rest of the parameters demonstrated moderate concordance in readings (kappa = 0.41 to 0.60). Three echo parameters (aortic dimension, VSD on plain 2D and PDA on plain 2D) required adjusted kappa coefficients, since existing data points for the said parameters were inadequate for analysis (not all data options were represented).

Table 5. Concordance of onsite and offsite readings according to pre-specified echocardiographic parameters
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In terms of category of discrepancy, Figure 3 shows 18 of the 68 (26%) sessions had identical readings across all parameters. Meanwhile, 47 of the 68 sessions (69%) had reading discrepancies of major significance, while 3 (4%) with minor significance, and none with intermediate significance.

Figure 3.
figure 3

Distribution of FaceTime sessions (N=68) in terms of category of discrepancy

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Comparison of diagnoses with reference standard

The impact of contrast echocardiography on the accuracy of final diagnosis at both onsite and offsite venues was assessed by comparing them to the official test reports, which served as the reference standard. Accuracy rates were comparable for pre-contrast onsite (51%) and offsite (54%) diagnoses, with a substantial improvement in post-contrast readings (88% onsite and 79% offsite) after incorporation of contrast echo parameters (Figure 4).

Figure 4.
figure 4

Percentage of readings (onsite and offsite) with accurate diagnoses (preand post-contrast) compared to the reference standard

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Using the official test reports as reference standard, 19 of 68 sessions differed in the final diagnoses (Table 6). There were 13 instances of wrong diagnoses at onsite and 21 at offsite. The onsite reader overdiagnosed 2 cases of PDA, 3 cases of PLSVC, and 4 cases of ASD, while missing 2 cases of PFO, 1 case of PLSVC and 1 case of possible cor triatrium. The offsite reader overdiagnosed 1 case of PDA, 1 case of VSD, 1 case of PFO, 3 cases of PLSVC, 7 cases of ASD, while missing 4 cases of PFO, 1 case of PLSVC, 2 cases of ASD, and 1 case of PDA.

Table 6. Official, onsite and offsite diagnoses of FaceTime sessions with discrepant readings (N=19)
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Technical aspects of videoconferencing sessions

All 68 sessions were conducted using an iPad2 device at the onsite venue and an iPad3 device at the offsite venue. Internet access was obtained in most sessions via WiFi capability provided by a portable, “pocket Wifi” device, with 10 of 68 sessions making use of 3G capability using the personal hotspot feature of an iPhone4S mobile device. Both sites connected to a host server (Globe Telecommunications, Inc.) located approximately 10 kilometers (Makati City) from the study site (Quezon City). Almost all sessions (66 of 68) were conducted between 2:00 and 5:00 PM, with the session duration ranging from 5 to 31 minutes, with a mean duration of 13 ± 5 minutes, (Table 7).

Successful transmission was achieved in all 68 sessions. The mean lag time to successful FaceTime connection was 101 ± 110 seconds, with 55 of 68 sessions establishing FaceTime connection under 3 minutes. One session took 10 minutes before successful connection was obtained, probably due to internet traffic. Twelve sessions were successfully established only after at least 4 call attempts.

Overall video and audio quality were acceptable for all 68 sessions. The average scores were 3.6 ± 0.6 (onsite) and 3.7 ± 0.5 (offsite) for video quality and 3.8 ± 0.4 (onsite) and 3.6 ± 0.6 (offsite) for audio quality, with 4 being the possible maximum score. The average lag time to transmission, or PING value was 183 ms for onsite and 203 ms for offsite. The average download speed was 1.89 Mbps for onsite and 1.97 Mbps for offsite, while the average upload speed was 0.32 Mbps for onsite and 0.33 Mbps for offsite (Table 6). Figure 5 shows sample images of the echocardiogram viewed simulataneously at onsite and offsite venues, demonstrating preserved image quality even after transmission to the offsite venue.

Table 7. Technical aspects and characteristics of videoconferencing (FaceTime) sessions
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Figure 5.
figure 5

Comparison of image quality of echo clips on (A) plain 2D, (B) color Doppler, and (C) contrast echocardiography as viewed simultaneously at onsite and offsite venues

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Discussion

This study demonstrates what appears to be the first local attempt to investigate the role of telemedicine in the field of adult echocardiography. Our experience reveals the potential for long-distance, real-time and interactive echocardiography to secure a place in the management of adult patients with structural or congenital heart diseases.

Concordance of onsite and offsite readings

The main objective of the study was to assess the concordance of readings made using 2 different methods of echocardiographic interpretation: 1) the standard, onsite reading of echo videos on a computer or television screen, and 2) the proposed, offsite reading of echo videos on a portable device, such as the iPad. In assessing concordance of readings between these two methods, the Kappa coefficient is utilized, which is a statistical measure of inter-rater or inter-annotator agreement. Kappa values of > 0.60 are considered to represent good agreement. The classification provided by Altman and colleagues8 refines this further by assigning specific kappa ranges to represent strength of agreement: < 0.20 (poor), 0.21 – 0.40 (fair), 0.41 – 0.60 (moderate), 0.61 – 0.80 (good), 0.81 – 1.00 (very good). The kappa coefficient is generally considered to be a more robust measure than simple percent agreement calculation since κ takes into account the agreement occurring by chance.

The study showed varying Kappa coefficients for the 22 echo parameters, with the higher values being obtained for measurement of the right-sided chambers (right atrium, right ventricle, pulmonary artery) as well as color Doppler assessment of selected lesions (ASD and PDA) and interpretation of contrast patterns. Although it is beyond the scope of this study to justify the reasons for such disparity in Kappa values, some theories are worth mentioning. In terms of chamber size evaluation, it appears that greater concordance is achieved when abnormalities are present, moreso if they are visually profound, such as right ventricular and right atrial dilatation brought about by augmented right-sided loading from an atrial septal defect with left-to-right shunting. This was evident since majority of the lesions included in the study were ASDs. Meanwhile, one possible explanation for the maximum concordance in assessment of PDA on plain 2D is the fact that none of the sessions had confirmed PDA on the official reports.

Detection of abnormal contrast patterns was comparable for both onsite and offsite readings, with a Kappa coefficient of 0.68. However, agreement was diminished for detection of negative contrast (Kappa = 0.42) as opposed to recognition of positive contrast effect (Kappa = 0.65). It is surmised that assessment of positive echoes (contrast bubbles appearing in a generally echolucent LA) is much easier than discrimination of negative echoes (represented as a jet of non-opacified blood, or absence of contrast bubbles in a chamber filled entirely with bubbles).

Diagnostic impact of contrast echocardiography

The value of contrast echocardiography in improving diagnostic accuracy was demonstrated in this study. The good concordance of post-contrast diagnoses (0.71) as opposed to the moderate concordance of pre-contrast diagnoses (0.50) signifies that onsite and and offsite readings become more comparable once contrast echo is incorporated into the formulation of a diagnosis. Meanwhile, using the officiallysigned out diagnosis as the reference standard, the onsite and offsite pre-contrast readings had diagnostic accuracy rates of 51% and 54%, respectively. However, after incorporation of contrast echo in the readings, the accuracy of onsite and offsite post-contrast readings increased to 88% and 79%, respectively. This once again suggests the incremental benefit of contrast echo in improving the diagnostic accuracy of echocardiographic readers.

Among the structural or shunt anomalies included in the study, ASD was the most prevalent (24%). Only one subject had an official diagnosis of VSD, particularly of the perimembranous type, with a concomitant persistent left superior vena cava. Onsite and onsite readings were identical, diagnosing the lesion during the pre- and post-contrast phase of the reading. This points to the sufficient diagnostic capacity of color Doppler in diagnosing VSD, reinforcing the previous observation that the use of contrast agents for the detection of VSD has diminished since the advent of color Doppler echocardiography.7

Logistical aspects of the proposed technology application

The clinical application of tele-echocardiography for the diagnosis of grown-up congenital heart disease has not been thoroughly investigated. However, several endeavours at the foreign scene have already been undertaken in recent years, showing great promise for the use of portable devices in the management and care of pediatric patients. In 2007, Sekar and colleagues presented their experience of 102 pediatric telecardiology consultations between a tertiary care cardiac center and a remote rural hospital located 120 miles away. Using the Very Small Aperture Terminal (VSAT) satellite bandwidth provided by the Indian Space Research Organization, an S-video link between the echocardiographic and videoconferencing equipment at the remote center allowed the specialist to view images in real time. The teleconference resulted in the ruling out of pathology in 49% of cases and diagnosis of cardiac problems in 51% of children, of whom 29% required surgery. This eventually led to successful cardiac surgery in 18 patients.9 In the same year, Low and associates demonstrated the acceptability of video display and audio quality of iPod touch-delivered videos taken of a hypothetical intra-operative set-up, intended for remote supervision of anaesthesiologists.10 In 2011, Dr. Armstrong and his colleagues used real-time mobile phone-based videoconferencing to augment diagnosis and care for a patient on routine post-operative follow up after reconstructive surgery. Through an impromptu “FaceTime” consultation between the operating surgeon and his colleagues, the former was able to discuss incision planning, resection requirements and subsequent surgical staging and successfully operate on the limb-threatening infection on an urgent basis.11

Among the available software in the market capable of providing videoconferencing technology, Microsoft’s Skype and Apple Inc.’s FaceTime have recently emerged as viable and potentially popular options. Launched in August 2003 and acquired in May 2011 by Microsoft Corporation, Skype is a proprietary voice-over Internet Protocol service that enables users to communicate through voice, video, and instant messaging over the Internet.12 Although predominantly an audio-centric application, Skype can deal with low connection rates and has broader connectivity. Introduced by Apple, Inc. in February 2011, FaceTime is a video calling software application developed for supported mobile devices running the iOS, in addition to Macintosh computers running Mac OS X 10.6.6 and higher. It is supported on any iOS device with a forward-facing camera (all iOS devices released since the iPhone 4) and on any Macintosh computer equipped with a FaceTime Camera.

The video conferencing setup only requires a FaceTimeenabled Macintosh computer with an Internet connection or a FaceTime-enabled iOS device with a Wi-Fi connection. Although some users have commented on limited connectivity (both parties should be using Apple products), FaceTime appears to be the better choice when it comes to video conferencing functions due to its simplicity of setup and user-friendliness, excellent video quality with rapid frame rate, and good audio quality.

Issues on security and privacy of health information

Despite the recent hype and interest in the use of remote imaging for telemedicine, certain sceptics have understandably raised concerns regarding not only the quality of images, but also the applicability of such set-ups in different localities as well as the acceptability among targeted end-users. There is also the legitimate concern regarding the security of data and preservation of patient privacy during such electronic healthcare transactions. Under the Privacy Rule of the Health Insurance Portability and Accountability Act of 1996, covered entities are mandated to take reasonable steps to ensure the confidentiality of communications with individuals. Furthermore, the Security Rule of the same document calls for implementation of technical safeguards to control access to computer systems and enable covered entities to protect communications containing protected health information (PHI) transmitted electronically over open networks from being intercepted by anyone other than the intended recipient.13

Apple authorities have already issued statements claiming that the FaceTime conversation stream is encrypted from end to end, and that each session has unique session keys for each user, making FaceTime HIPAA-compliant. They follow this up with a statement of condition, saying that this level of data security can be achieved as long as the wireless network being used utilizes WPA2 Enterprise security with 128-bit AES encryption.14 Wi-Fi Protected Access (WPA) and Wi- Fi Protected Access II (WPA2) are two security protocols and security certification programs developed by the Wi-Fi Alliance to secure wireless computer networks. The Alliance defined these in response to serious weaknesses researchers had found in the previous system, WEP (Wired Equivalent Privacy).15

Scope and Limitations

Since a number of factors were beyond the control of the investigators (e.g. type and frequency of new adult congenital consult referrals for contrast echocardiography), the echo records of all adult patients who were subjected to contrast echocardiography at the Philippine Heart Center during a selected time-frame were retrospectively reviewed and considered for inclusion in the study, regardless of the initial cardiac diagnosis. FaceTime sessions were set at predetermined dates and times, to adjust to the availability of the echo readers. Since the contrast echocardiograms were retrospectively reviewed, certain technical aspects could not be controlled and include the following: 1) competency level (assessed by number of years in actual practice) of the echo technicians who performed the contrast echocardiogram, 2) quality of injection technique, 3) performance or nonperformance of provocative manuevers (e.g. Valsalva) to enhance visualization of suspected shunts.

Implications of the Study

The role of telemedicine in the management of today’s adult heart diseases becomes increasingly relevant in the local setting where several areas of the archipelago have limited access to much-needed expert opinion and care. The present study is a modest attempt to demonstrate what appears to be the potential impact of long-distance echocardiography for the diagnosis of emerging adult congenital heart diseases. Although only a quasi-experimental design was employed, such findings may find utility in actual, real-time echocardiography of patients.

The present study demonstrated the feasibility and utility of telemedicine in the remote diagnosis of cardiac structural and shunt anomalies in the adult or grown-up population. This development is relevant especially in the local setting, where technological interconnectivity can potentially bridge healthcare gaps brought about by geographical factors. A number of studies have already proven the clinical, economic and social impact of digital echocardiography. Studies on neonates with congenital heart disease showed that teleechocardiography provided point-of-care diagnostic accuracy and ultimately improved patient management.6,16 A costeffectiveness study by Hooper and colleagues17 revealed less expenditure from tele-echocardiography sessions compared to overhead costs brought about by requiring cardiologists and cardiac sonographers to travel to remote areas for onsite echocardiography. Meanwhile, a study on screening fetal echocardiography via telemedical means demonstrated community and individual patient acceptance of tele-echocardiography, creating a favorable impact on the traditional healthcare system of the studied population.18

The technical feasibility of FaceTime sessions for echocardiographic videoconferencing is crucial in a time when advanced technology for internet transmission of large-sized echo videos is currently not yet widely-available and accessible. The FaceTime option appears very viable, especially in an era when I-phones and iPad devices are almost common commodity for physicians and even for the middle-class segment of the population. The logistical requirements are very much attainable, with a successful session being dependent only on a strong internet connection and two devices capable of Facetime transmission. More importantly, this mode of videoconferencing allows onsite sonographers and physicians from rural areas to obtain the expert opinion of urban-based echocardiographers through realtime viewing of echo images. Such point-of-care service can be provided by echocardiographers at virtually any time or place, whether in their clinic or in comfort of their own homes.

Conclusion and Recommendations

Our study showed that the onsite interpretations of contrast echocardiograms of suspected cardiac shunt anomalies made by echocardiographers are comparable to their offsite readings made via the real-time videoconferencing technology of FaceTime, with an overall agreement rate of 89% and kappa coefficients of more than 0.60. Although a number of sessions showed discrepancies in various aspects of the echo reading (assessment of chamber and great vessel size, detection of anomalies on plain echo, color Doppler and contrast echo), the final diagnosis was similar in majority (84%) of the sessions. Moreover, the method of FaceTime videoconferencing demonstrated technical feasibility, generating acceptable internet speeds as well as obtaining high scores for both audio and video quality assessment at both ends of the transaction. These findings suggest a role for tele-echocardiography in long-distance, point-ofcare diagnosis of patients with potential structural or shunt anomalies that may require immediate specialist attention.

The tremendous potential of digital tele-echocardiography necessitates further investigative efforts in order to maximize its utility in various settings and clinical scenarios. The authors recommend that succeeding research endeavors look into the clinical impact of actual long-distance videoconferencing on the accuracy of diagnosis as well as the course of management of patients with congenital heart disease. A parallel study can be likewise made to assess the cost-effectiveness of such a strategy, with the end goal of making policy recommendations at the local and national levels.

Disclosure of Conflict of Interest

The investigators of this study have no personal or indirect involvement with the manufacturers of the Apple, Inc. devices and, therefore, have no conflict of interest to declare.

Acknowledgment

The investigators of this study recognize the invaluable contribution of the following people in making the study possible: from the Non-invasive Cardiology Division— Dr. Maria Christie Mendoza-Reyes, Dr. Maria Johanna M. Jaluague and Dr. Belle Ramos-Salamanca (Clinical Research Fellows); Ms. Ayin Senga (chief technologist), Mr. Rylan Ubaldo, Ms. Meliza Mendoza, Mr. Nathaniel Helera, Ms. Giselle Abad, Mrs. Jelyn Vallarta, Ms. Lovely Ann Alarilla and the rest of the sonographers; Ms. Asuncion S. Rara, Ms. Rowena N. Linacero, Mr. Brian M. Abundo, Mr. Raymond V. Rosani, and the support staff; from the Research Division of the Philippine Heart Center—Mercedita Parazo, Maria Fe Bulac, and the consultant and support staff of the Technical Review Committee and Institutional and Ethics Regulatory Board of the Philippine Heart Center; and Mr. Jose Crisanto Magno, for his expert advise on the logistical and telecommunications aspects of the study.