Heart disease in the Netherlands: a quantitative update

Since its peak in the late 1950s (in women) and the early 1970s (in men), cardiovascular mortality in the Netherlands has gradually declined. This reduction has occurred despite the larger number of elderly persons as well as the more advanced age of contemporary Dutch citizens. After correction for these changes (standardisation), the drop in cardiovascular mortality that has taken place, a reduction of about 70 %, is considerable [1, 2]. Cardiovascular mortality from 1950 to 2012 is delineated in Fig. 1. After 1980, the cardiovascular mortality rates in women and men tend to converge [2].

Open image in new window

Inspection of the data makes it clear that most cardiovascular deaths result from atherosclerotic disease affecting the coronary, cerebral, and other arterial vessels. Women die more often from more ‘mature’ atherosclerotic manifestations such as stroke and heart failure than men: the latter die in larger numbers from myocardial infarction (MI). However, one should appreciate that the primary cause of death is often difficult to ascertain and, in particular in persons over 80 years of age, may not be accurate [3, 4]. For instance, the number of 766 individuals supposedly dying from infectious CVD could well be false, since neither the incidence of bacterial endocarditis (estimated to be approximately 300 cases per year in the Netherlands) nor its clinical course (estimated case fatality less than 20 %) are able to account for the numbers reported [5]. Although the incidence of infective endocarditis has been stable in other parts of Europe over the past decades [6], it must be noted that contemporary data from the Netherlands are lacking.

On their own, atrial fibrillation (AF) and hypertension represent unlikely primary causes of death, yet thousands of deaths are attributed to these morbid conditions. Also, the mortality statistics combine causes and modes of death. For instance, heart failure is not a disease entity in itself, but merely a symptom of underlying cardiac conditions. Presumably many more persons die from the consequences of heart failure [7], but these deaths are attributed to for instance coronary, valvular, or congenital heart disease. This is likewise also the case for sudden cardiac death, which now only constitutes a minor part of the cause of death statistics (‘Other heart diseases’ in Table 2), whereas Dutch population-based studies have demonstrated that approximately 10 % of all deaths in adults fulfil the criteria for sudden cardiac death [8, 9].

Significant discordance in mortality statistics based on self-reports of hospitals (performance indicators) and data from clinical registries is noted. Hospital mortality from MI is between 5 and 10 % according to data from Statistics Netherlands (CBS), with age being the main determinant of adverse outcomes.

The incidence of first MI has been declining by about 3 to 4 % per year in the last decade, both in men and women. Total incidence declined by 38 % in men and by 32 % in women between 1998 and 2007 [10, 11].

The total number of surgical procedures, including paediatric surgery, has gradually increased over the years to 17,293 operations in 2012, performed in 16 surgical centres (Fig. 3) [1]. Seven percent of these interventions are ‘urgent’ (i.e. take place before the start of the next working day after the decision to operate has been taken) [12].

Open image in new window

About two-thirds of the 16,262 operations in adults in 2012 involved coronary artery bypass surgery (CABG), while half of all surgical procedures are represented by isolated CABG (source: Supervisory Committee for Cardiac Interventions in the Netherlands (BHN)). In these procedures, the use of only arterial grafts has increased from 15 % in 1995 to nearly 26 % in 2011 [12]. The 30-day mortality of isolated CABG in 2010 was 1.2 % [1].

In 2012, a total of 3020 operations were related to diseases of the aortic valve, and in 41 % of these procedures coronary bypass grafts were implanted (source: Supervisory Committee for Cardiac Interventions in the Netherlands (BHN)). The type of prostheses implanted has gradually changed from mainly mechanical prostheses in the 1990s to the use of bio-prostheses in nearly 80 % of the operations nowadays. In addition to CABG and aortic valve surgery, mitral valve surgery is the most common indication for cardiac surgery with approximately 1750 operations annually. Concomitant CABG is performed in 36 % of these operations [1]. The proportion of mitral valve repairs has increased to over 75 %. Active endocarditis is reported in less than 200 surgical procedures per year [12]. Overall the 30-day mortality associated with valvular surgery in 2010 was 3.6 % [1].

Mainly as a result of varying availability of donor hearts, the number of yearly heart transplants has varied considerably over the years. On average, about 40 to 50 transplants are performed each year in three academic medical centres [13].

Other procedures include aortic surgery (approximately 1000 operations per year), transcatheter aortic valve implantation, and less frequently performed procedures such as surgical left ventricle reconstruction, ventricular septal rupture repair, rhythm surgery (as a concomitant or as a stand-alone procedure), surgery for correction of congenital heart disease, or management of cardiac trauma [14, 15].

While the number of surgical procedures has only risen gradually in the last decade, this has not been the case with the percutaneous interventions (PCIs). Their number has risen much more quickly in recent years. For instance, in 2012, 45,305 PCIs were performed in 30 centres, and this number represents more than a doubling of these procedures in a time frame of only 10 years (Fig. 3) [1, 16]. The most frequent indications for PCI were stable angina (42 %), acute MI (33 %) and unstable angina (22 %). Over 90 % of the procedures involved stent placement [13].

Based on the Dutch ICD and Pacemaker Registry (DIPR), an additional 10,389 pacemakers (excluding cardiac resynchronisation therapy (CRT)) were implanted in 92 contributing hospitals in 2011. A fourth of the pacemaker implantations were replacements of another device.

As with most other CVD, the presence of heart failure casts a shadow over the last phase of life in a considerable number of Dutch individuals. Between 20 and 30 % of the general population will develop some form of heart failure, usually when they are over 70 years of age [17]. Incidence rates in the Netherlands increase steeply from about 1 per 1000 person-years below 60 years of age to almost 50 per 1000 person-years in those aged 90 years and over.

Due to the ageing of the population, an increase in the number of patients with heart failure in the Netherlands was already predicted in the 1990s [18]. Contemporary data have confirmed that forecast, and an estimated 120,000 individuals with heart failure, about 1 % of the adult Dutch population, were reportedly present in 2008. The continuing ageing of the population is expected to raise their numbers to an approximate 200,000 in the coming decade [19].

The majority of heart failure is diagnosed in chronic stages, but episodes of acute cardiac decompensation can lead to hospitalisation. In 2011, 29,916 hospital admissions were registered in the Netherlands with heart failure as the primary discharge diagnosis (source: Dutch Hospital Data (LMR)) [11]. The numbers are equally distributed over both sexes. This number includes readmissions which are known to be frequent in patients with heart failure. Recent Dutch data on the ratio of first admissions to readmissions is lacking, but studies from U.S. registries consistently report 30-day readmission rates up to 25 % [20]. Between 1980 and 1990, the number of hospitalisations for heart failure increased by about 50 %. Thereafter, a decrease was observed but, as of 2002, the number of hospitalised patients increased again, although the total number of days spent in hospital has more or less stabilised [19].

The prognosis of patients with heart failure has been described as being more ‘malignant’ than that of many common cancers [21]. Five-year survival after the initial diagnosis ranges from approximately 25 to 35 % in population-based studies [17]. The in-hospital mortality associated with decompensated heart failure is poor, even for first occurrences, and has been reported to be in the order of 15 % in the Netherlands [17]. This is worse than the currently observed in-hospital mortality associated with acute MI.

The absolute number of Dutch citizens dying either from MI or heart failure has been depicted in Fig. 4, and clearly shows the direction of the change in both causes of death. Since 2012, the number of deaths from heart failure (n = 6761) has surpassed the mortality from MI (n = 6195) (Table 2 and Fig. 4) [1].

Open image in new window

AF is the most common sustained cardiac arrhythmia. The condition carries serious health consequences, including increased risk for stroke and heart failure. AF is found to be present in about a quarter of patients presenting with an ischaemic stroke. The presence of many other cardio-metabolic disorders, such as coronary and valvular heart disease, cardiomyopathies, hypertension, and diabetes, predispose to the development of AF.

Estimates from a Dutch population-based cohort study indicate that the lifetime risk of AF is in the order of 20 to 25 %. As with heart failure, its occurrence strongly increases with age: the incidence rate of AF below 60 years of age is less than 1 per 1000 person-years, but rises to almost 20 per 1000 person-years in persons over 85 years of age [22]. These estimates may underestimate the true incidence since the presence of AF, either permanent or paroxysmal, may go undetected clinically.

On the basis of the best available data, an estimated 260,000 Dutch individuals are currently affected by AF [23]. These were responsible for 42,188 hospital admissions in 2011 with AF as the primary discharge diagnosis (source: Dutch Hospital Data (LMR)) [11]. Between 1994 and 2006, no major changes in its prevalence were observed but, given current demographic developments, an increase in the number of persons with AF in the coming years is projected [23].

During the last years, the number of hospitalisations associated with CVD has stabilised at around 400,000 (2400 per 100,000 inhabitants). Almost 115,000 (29 %) of these comprise 1 day admissions related to diagnostic or therapeutic procedures, or observations of cardiovascular symptoms. In the remaining cases, the mean duration of hospital stay is about 6 days (source: Statistics Netherlands (CBS)). Admission rates for rhythm disturbances are on the rise [11].