1348638 - Right ventricular dyssynchrony assessed in multiple MR views predicts outcome in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) alters right ventricular (RV) function and is indicative of poor outcome [1]. Post-systolic contraction (PSC) occurs when the heart contracts after pulmonary valve closure and can be present in PAH [2]. When peak-systolic strain and PSC occur at different time points and regions of the RV, it generates dyssynchrony and inefficient contraction [3, 4]. The aim of this study was to investigate if RV PSC and dyssynchrony are prognostic markers of transplantation-free survival in PAH and if multiple RV views, including several regions for dyssynchrony assessment, improve this prognostication.

Methods:

One hundred-one patients (58 ± 19 years, 66% women) with PAH undergoing cardiac magnetic resonance (CMR) between 2003-2021 were included. For strain analysis, RV endocardium was delineated in cine images in a midventricular short axis slice (SAX), 4-chamber (4ch) view and RV 3-chamber (RV3ch) view (Figure 1). Presence, duration of PSC, and RV dyssynchrony were analyzed from strain curves. PSC was defined as peak strain occurring after pulmonary valve closure and duration of PSC as the time from pulmonary valvular closure to peak strain. RV dyssynchrony was defined as the standard deviation of time to peak strain in one (4ch), two (4ch and SAX) or three views (4ch, SAX and RV3ch) assessing two, four or six walls, respectively (Figure 2). Outcome was defined as death or lung transplantation. Univariate and bivariate cox regression analysis (adjusted for age) was performed.

Results: During follow-up of median 37 [51] months there were 60 events (55 deaths and 5 lung transplantations). Presence and duration of PSC and dyssynchrony assessed from one or two views were not associated with outcome (Table 1). Age in univariate analysis, dyssynchrony assessed from three views in univariate and bivariate analysis and RV 4ch strain bivariate analysis were associated with outcome (Table 1).

Conclusion: Right ventricular dyssynchrony from three views were associated with outcome in PAH, while assessing dyssynchrony from one or two views and presence and duration of PSC were not. This implies that assessing multiple RV views in PAH improves the prognostication.