Epidemiology and long-term survival of pulmonary arterial hypertension in the Czech Republic: a retrospective analysis of a nationwide registry

Abstract

Background: Pulmonary arterial hypertension (PAH) is a severe and progressive disease characterized by increased pulmonary vascular resistance, ultimately leading to right heart failure and death. Epidemiological data from national registries are growing worldwide, but are still unavailable in Eastern Europe.

Methods: A PAH registry was initiated in January 2007 using a nationwide network of echocardiographic centers and four diagnostic centers that specialize in PAH. All patients aged above 18 years, diagnosed with PAH and monitored between January 2000 and December 2007 were included. Patients diagnosed with PAH between January and December 2007 were classified as incident. The survival analyses were performed up to the end of 2010. Prognostic factors at the time of diagnosis were identified using uni- and multivariable Cox proportional hazard models.

Results: Overall, 191 patients were included (100 prevalent cases, 91 incident cases). Patients were predominantly female (n = 125) and had a mean age of 51.9 ± 16.9 years. Incident patients were significantly older at the time of diagnosis than prevalent patients (p < 0.001). Most patients (60.7%) had idiopathic PAH; 20.4% had PAH associated with congenital heart disease and 11.4% had PAH associated with connective tissue disease. Estimates of prevalence and incidence of PAH in adults were 22.4 cases per million and 10.7 cases per million per year, respectively. The 1-, 2- and 3-year survival rates in the incident PAH cohort were 89% (95% confidence intervals [CI] 83-95%), 78% (95% CI 70-87%) and 74% (95% CI 65-83%), respectively. Lower survival rates were significantly associated with higher age (hazard ratio [HR] 6.6 95% CI 1.4-30.9) and lower creatinine clearance (HR 3.3 95% CI 1.1-9.7).

Conclusion: This is the first study in Eastern Europe to describe the prevalence, incidence and survival of patients with PAH from a national representative registry. This registry from the Czech Republic highlights that diagnosis of PAH is frequently made late in the disease continuum when patients have significant functional impairment.

Figure 1

Overall survival in the incident population. A) All patients with PAH; B) Patients with idiopathic or heritable PAH (n = 53) or APAH-CHD (n = 23).

Figure 2

Factors associated with survival in the incident population. A) All patients (n = 91); B) Patients with idiopathic or heritable PAH (n = 53). Footnote: Optimal cut-off levels for parameters included in the Cox proportional hazard methods were identified using time-dependent receiver operating characteristic analysis [16]. The selection of variables for the multivariate model was based on univariate statistical significance <0.1 followed by redundancy analysis and a forward stepwise algorithm.