Right ventricular dyssynchrony predicts outcome in pulmonary arterial hypertension when assessed in multiple cardiac magnetic resonance views.

Background: Right ventricular (RV) dyssynchrony or post systolic contraction (PSC) causes inefficient pumping and has not been investigated as a prognostic marker in pulmonary arterial hypertension (PAH). The objective was to investigate if RV dyssynchrony and PSC are prognostic markers of transplantation-free survival in PAH and if multiple RV views improve prognostication.

Methods: Patients with PAH undergoing cardiovascular magnetic resonance between 2003 and 2021 were included. For strain analysis, endocardial end-diastolic RV contours were delineated in RV three-chamber (RV3ch), four-chamber (4ch), and midventricular short-axis (SAX) slice. RV dyssynchrony was defined as the standard deviation of time to peak strain in the walls from one (4ch), two (4ch and SAX), or three views (4ch, SAX, and RV3ch). PSC was defined as peak strain occurring after pulmonary valve closure. Outcome was defined as death or lung transplantation.

Results: One hundred and one patients (58 ± 19 years, 66% (67/101) women) were included. Median follow-up was 37 [51] months. There were 60 events (55 deaths and 5 lung transplantations). Outcome was associated with RV dyssynchrony from three views and with RV strain in 4ch. An increase in RV dyssynchrony-in three views-by 1% was associated with a 10% increased risk of lung transplantation or death. There was no association between outcome and RV dyssynchrony in one or two views nor with PSC.

Conclusion: RV dyssynchrony in three views was associated with outcome in PAH, whereas assessing dyssynchrony from one or two views and PSC was not. This implies that assessment of multiple instead of single RV views could potentially be used for prognostication in PAH.