Pulmonary arterial hypertension in congenital heart disease: An epidemiologic perspective from a Dutch registry

https://doi.org/10.1016/j.ijcard.2006.09.017Get rights and content

Abstract

Background

Pulmonary arterial hypertension (PAH) associated with congenital heart disease is usually the result of a large systemic-to-pulmonary shunt, and often leads to right ventricular failure and early death. The purpose of this study was to determine the prevalence of PAH among adult patients included in a national registry of congenital heart disease and to assess the relation between patient characteristics and PAH.

Methods

Patients with PAH associated with a septal defect were identified from the registry. Gender, age, underlying diagnosis, previous closure, age at repair and NYHA classification were recorded. PAH was defined as a systolic pulmonary arterial pressure (sPAP) greater than 40 mm Hg, estimated by means of echocardiographical evaluation.

Results

The prevalence of PAH among all 5970 registered adult patients with congenital heart disease was 4.2%. Of 1824 patients with a septal defect in the registry, 112 patients (6.1%) had PAH. Median age of these patients was 38 years (range 18–81 years) and 40% were male. Of these patients, 58% had the Eisenmenger syndrome. Among the patients with a previously closed septal defect, 30 had PAH (3%). Ventricular septal defect (VSD) was the most frequent underlying defect (42%) among patients with PAH and a septal defect. Female sex (Odds ratio = 1.5, p = 0.001) and sPAP (Odds ratio = 0.04, p < 0.001) were independently associated with a decreased functional class.

Conclusion

PAH is common in adult patients with congenital heart disease. In our registry the prevalence of PAH in septal defects is around 6%. More than half of these patients have the Eisenmenger syndrome, which accounts for 1% of the total population in the CONCOR registry. Whether the prevalence of PAH will decrease in the future as a result of early detection and intervention remains to be awaited.

Introduction

Pulmonary arterial hypertension (PAH) may lead to a decreased functional capacity, and right ventricular failure, and is often associated with early death [1]. The prevalence of PAH in patients with congenital heart disease is not known. It has been suggested that 10% of all adult patients with congenital heart disease sooner or later develop PAH [2], [3]. In the context of congenital heart disease, PAH may develop as a consequence of a systemic-to-pulmonary shunt. Due to systemic-to-pulmonary shunting, pulmonary blood flow increases. This leads to increased pressure in the pulmonary arteries, endothelial dysfunction and an increased vascular resistance. These changes may ultimately lead to a reversal of the systemic-to-pulmonary shunt accompanied by cyanosis [4], the so-called Eisenmenger syndrome. Eisenmenger syndrome is at the severe end of the spectrum of PAH and involves probably about 1–2% of patients with congenital heart disease [3].

Once the Eisenmenger syndrome exists, repair of the underlying defect is contraindicated. The right ventricle will be unable to generate enough pressure to overcome the high pulmonary vascular resistance and decompensate. Surgical correction of the congenital heart defect, during childhood, before the characteristic changes in the pulmonary arteries have started to appear, will mostly prevent the development of PAH [5], [6], [7].

A few studies have been devoted to the clinical course of the Eisenmenger syndrome, but little is known about the prevalence and clinical impact of PAH among patients with congenital heart defects. Various congenital heart defects may lead to PAH, such as univentricular heart, truncus arteriosus, patent ductus arteriosus and septal defects, but PAH may also develop as a result of surgical shunts (Potts, Waterston, Blalock–Taussig). Although PAH may occur in the context of a wide range of different defects, by far the largest proportion of patients with PAH have a septal defect as underlying defect. For that reason, in this study we focused in particular on ventricular septal defect (VSD), primum or secundum atrial septal defect (ASD I or ASD II, respectively) or complete atrioventricular septal defect (AVSD). As early surgery of the defect will mostly prevent the development of PAH, it is especially important to be informed on the risk of PAH in these patients. What is the prevalence of PAH in this category of patients, and what are the clinical characteristics of adult patients with PAH? To answer these questions, we analyzed data from the CONCOR (CONgenital COR vitia) registry, a nationwide registry of adult patients with congenital heart defects in the Netherlands. This registry was set up as a basis for studying the epidemiology of congenital heart defects and includes patients with structural congenital heart defects or Marfan syndrome. In the registry are not included, patients with cardiomyopathies (i.e. arrhythmogenic right ventricular dysplasia, hypertrophic cardiomyopathy and dilated cardiomyopathy) or inherited diseases leading to genetically determined cardiac arrhythmias and sudden death (i.e. long QT syndrome, Brugada syndrome) [8]. Consistent input of data by dedicated nurses travelling along the participating hospitals may guarantee a rather high consistency of data input and a rather low amount of missing data.

Section snippets

Patient population

In November 2005, the CONCOR registry contained diagnoses and clinical events of 5970 adult patients with congenital heart disease from 86 tertiary and regional hospitals [8]. Our assessment of the prevalence of PAH consisted of two parts. In a first, global, analysis, we estimated the prevalence of PAH among all patients at risk for developing PAH. Thus, we defined a total “population at risk”, which included all patients in the registry who had as primary diagnosis a defect that may lead to

Population

Of the total population included in the CONCOR registry (5970 patients) from 86 hospitals, the population at risk existed of 2389 patients (see Table 1), having one of the defects mentioned in the methods section. Of those, 248 (10%) had PAH. In total, the prevalence of PAH among congenital heart disease patients was 4.2%. Further, 1824 patients (31%) were identified as having a septal defect; in 899 of these patients the septal defect had been closed. Of the 1824 patients with a septal defect,

Discussion

Our data show that the prevalence of PAH among patients with a septal defect is at least 6.1% among adult patients included in the CONCOR registry. The estimated prevalence of PAH among all patients included in the CONCOR registry as a whole is at least 4.2%. One percent of all patients (5970) registered in the CONCOR registry had the Eisenmenger syndrome. VSD was the most common underlying diagnosis among patients with PAH in the septal defect group. Female sex and increased sPAP were both

References (21)

There are more references available in the full text version of this article.

Cited by (0)

View full text