Right atrial and ventricular strain detects subclinical changes in right ventricular function in precapillary pulmonary hypertension.

ABSTRACT

Right ventricular (RV) ejection fraction (EF) by cardiac magnetic resonance (CMR) correlates to outcome in precapillary pulmonary hypertension (pPH) patients, but is insensitive to early changes. Strain might provide incremental information. In this study, we compare right atrial (RA) and RV strain in pPH patients to healthy controls, and evaluate the prognostic value of strain in pPH. In this cross-sectional study, 45 pPH patients and 20 healthy controls underwent CMR, and feature-tracking derived RA and RV strain were evaluated. pPH patients had impaired RA reservoir and conduit strain, and RV longitudinal strain (LS), compared to healthy controls. In pPH patients with preserved RVEF (≥ 50%, n = 18), RA reservoir (35% ± 9 vs. 41% ± 6, p = 0.02) and conduit strain (16% ± 8 vs. 23% ± 5, p = 0.004), and RV-LS (-25% ± 4 vs. -31% ± 4, p < 0.001) remained impaired, compared to healthy controls. The association of strain with the primary endpoint (combination of all-cause death, lung transplantation, and heart failure hospitalization) was evaluated using a multivariable Cox regression model. RV-LS (HR 1.18, 95%-CI 1.04-1.34, p = 0.01) and RA strain (reservoir HR 0.87, 95%-CI 0.80-0.94, p = 0.001; conduit HR 0.85, 95%-CI 0.75-0.97, p = 0.02, booster HR 0.81, 95%-CI 0.71-0.92, p = 0.001) were independent predictors of outcome, beyond clinical and imaging features. In conclusion, pPH patients have impaired RA strain and RV-LS, even when RVEF is preserved. In addition, RA strain and RV-LS were independent predictors of adverse prognosis. These results emphasize the incremental value of RA and RV strain analyses, to detect alterations in RV function, even before RVEF declines.