Even after years of stable response to therapy, patients with idiopathic pulmonary arterial hypertension (IPAH) may show an unexpected clinical deterioration due to progressive right ventricular (RV) failure. Therefore, the aim of this study was to assess in 5-year clinically stable patients with IPAH whether initial differences or subsequent changes in RV volumes precede late clinical progression.
Included were 22 clinically stable patients with IPAH as reflected by stable or improving New York Heart Association functional class II-III and exercise capacity during 5 years of follow-up. Twelve patients subsequently remained stable during a total follow-up of 10 years, whereas 10 other patients showed late progression leading to death or lung transplantation after a follow-up of 8 years. All patients underwent right-sided heart catheterization and cardiac MRI at baseline and at 1½, 3½, 6½, and, if still alive, 10 years follow-up.
Baseline hemodynamics were comparable in both groups and remained unchanged during the entire follow-up period. Baseline RV end-systolic volume (RVESV) was higher and RV ejection fraction (RVEF) was lower in late-progressive patients. Late-progressive patients demonstrated a gradually increased RV end-diastolic volume and RVESV and a decline in RVEF, whereas long-term stable patients did not show any RV changes.
In patients with stable IPAH for 5 years, subsequent late disease progression is preceded by changes in RV volumes. The results indicate that monitoring RV volumes anticipates clinical worsening, even at a time of apparent clinical stability.