Baseline Characteristics and Participant Disposition
The baseline characteristics of the ReCharge Trial patient population have been summarized previously . Of the 162 participants randomized to the vBloc group, 87 % were female, the mean age was 47 years, the mean BMI was 41 kg/m2
, 39 % had hypertension, 56 % had dyslipidemia, and 20 % had obstructive sleep apnea. Nine participants (6 %) had T2DM.
Seventy-six percent of the randomized vBloc participants (n = 123) remained in the trial at 24 months. The reasons for withdrawals in the vBloc group were as follows: 23 (14.2 %) subject decisions, 9 (5.6 %) for an adverse event, 2 lost to follow-up (1.2 %), and the other 5 due to intra-operative exclusions as a result of which the vBloc device was not implanted, which has been described previously . The withdrawals for an adverse event were due to pain at the neuroregulator site in five cases, the need for MRI in two cases, heartburn in one case, and abdominal pain in another. As previously reported, eight participants required nine revisions in the first year of the study . There were four additional revisions between 12 and 24 months: two due to the adverse event of pain at the neuroregulator site, one due to twisted leads caused by the participant chronically rotating the neuroregulator in the subcutaneous pocket (“Twiddler’s syndrome”) where both leads and the neuroregulator were replaced, and one due to the inability to consistently recharge the neuroregulator which a neuroregulator replacement remedied. All revisions were uncomplicated, and the patients were released on the day of or day following the procedure.
The mean EWL among vBloc participants who presented for the 24-month visit was 21 % (95 % CI 16 to 26 %); the mean percent TWL was 8 % (95 % CI 6 to 10 %). Twenty participants did not present for the visit but remained in the study. The percentage of participants who achieved various TWL thresholds from at least 5 % to at least 15 % TWL were similar at 12 and 24 months (Table 1). Only 24 participants of the 77 randomized to the Sham arm remained in the trial who had not yet crossed over to active vBloc therapy. However, the mean weight loss among these individuals was only 4 % EWL (1 % TWL).
Improvements in Cardiovascular, Anthropometric, and Metabolic Parameters
Mean screening values for cardiovascular and anthropometric risk factors with average changes at yearly follow-up visits for all vBloc participants who presented for the visit and for the subset of participants with abnormal screening values are provided in Table 2. Overall, the improvements from baseline in systolic and diastolic blood pressure and waist circumference were significant; those with elevated blood pressure at baseline had two to three times greater improvements, which were also statistically significant.
Mean screening values and 12- and 24-month mean changes for metabolic obesity risk factors are shown for all vBloc participants who presented for the visit as well as those with abnormal screening values in Table 3. Among all vBloc participants, 24-month improvements from baseline were statistically significant for LDL cholesterol, HDL cholesterol, triglycerides, and HbA1c. Improvements were greater for all parameters among participants whose values were abnormal at baseline. Fasting plasma glucose was the only metabolic parameter that was not significantly impacted at 24 months. Among the subset of participants who met the criteria for metabolic syndrome at baseline, 50 % remitted from that diagnosis at 12 months and 47 % by 24 months (Table 4). Similarly, among the participants who were pre-diabetic at screening, 57 % had normal glucose profiles at 12 months and 50 % had normal values at 24 months (Table 5).
Quality of Life and Food Intake-Behavior
Significant improvements from baseline were observed in the IWQOL-Lite questionnaire at both 12 and 24 months among participants who received vBloc therapy (Table 6). From a mean score of 57 (on a 0 to 100 scale, where higher scores indicate greater quality of life), the mean improvement from screening was 20 points at both yearly visits.
As shown in Table 6, each of the three factors on the TFEQ results improved significantly from baseline. The hunger factor, of greatest interest since decreasing hunger and earlier satiety are considered to be the mechanism of action of vBloc therapy , was significantly decreased from a mean of 8 points (on a 0–14 scale, where higher scores indicate experiencing more sensations of hunger) at screening to 4 points at 12 months, which was sustained at 24 months. The disinhibition factor, which measures the ability to control emotional or social eating, and cognitive restraint, which assesses the ability to avoid weight-gaining behaviors by limiting consumption, was also significantly improved.
The related adverse event profile of the vBloc device cumulatively through 24 months was similar to that reported at 12 months (Table 7) . The most frequently reported related adverse events were heartburn and dyspepsia, neuroregulator site pain, other pain, abdominal pain, incision pain, nausea, eructation/belching, and dysphagia. Ninety-four percent of all adverse events were reported as mild or moderate in severity, and 83 % of events had resolved by 24 months.
All primary endpoint-related serious adverse events have been previously reported through 18 months, so the rate remained constant at 4.3 % [3, 6]. Three serious adverse events of infection, confusion with hallucinations, and brain tumor were reported and adjudicated by the independent clinical events committee to be unrelated to vBloc therapy.