Prognostic value of right ventricular ejection/filling parameters in IPAH using cardiac magnetic resonance: A prospective pilot study.

Abstract

The potential prognostic value of cardiovascular magnetic resonance (CMR)-derived right ventricular (RV) ejection/filling parameters in the assessment of RV function remains to be fully established. The goal of this study was to explore the prognostic value of these parameters in idiopathic pulmonary arterial hypertension (IPAH) patients. In this prospective investigation, newly diagnosed IPAH patients without targeted therapy were recruited. Patients underwent right heart catheterization (RHC), 6-min walk test and CMR imaging within 1 week. Cardiopulmonary haemodynamics derived from RHC, and RV ejection/filling parameters derived from CMR were collected. A total of 41 IPAH patients were recruited with the median follow-up time of 824 days. During this period, 13 patients significantly deteriorated and among them, 7 patients died. CMR-derived RV peak ejection rate (PER) correlated significantly with CMR-derived RV stroke volume index (r = 0.574, P < 0.001) and RV cardiac index (r = 0.611, P < 0.001), but had no significant correlation with RV end diastolic volume index (EDVI, r = 0.201, P = 0.208) and pulmonary vascular resistance (r = -0.134, P = 0.403). Multivariate Cox regression analysis showed that RV time to PER (TPER, hazard ratio (HR) = 1.010, 95% CI: 1.003-1.017, P = 0.005) and RV TPER/time of a cardiac cycle (TPER/TCC, HR = 1.085, 95% CI: 1.031-1.141, P = 0.002) were predictors of clinical deterioration after adjusting for N-terminal pro-brain natriuretic peptide (NT-proBNP) and RV EDVI. Kaplan-Meier survival analyses showed that patients with RV TPER ≥ 199.01 ms (log rank: P = 0.036) or RV TPER/TCC ≥ 20.02% (log rank: P = 0.007) had worse prognosis. CMR-derived RV TPER and TPER/TCC can reflect RV early systolic function, and may be promising predictors for long-term prognosis in IPAH patients.