Right ventriculo-arterial coupling in pulmonary hypertension: a magnetic resonance study

ObjectiveTo quantify right ventriculo-arterial coupling in pulmonary hypertension by combining standard right heart catheterisation (RHC) and cardiac magnetic resonance (CMR) and to estimate it non-invasively with CMR alone.DesignCross-sectional analysis in a retrospective cohort of consecutive patients.SettingTertiary care centre.Patients139 adults referred for pulmonary hypertension evaluation.InterventionsCMR and RHC within 2 days (n=151 test pairs).Main outcome measuresRight ventriculo-arterial coupling was quantified as the ratio of pulmonary artery (PA) effective elastance (Ea, index of arterial load) to right ventricular maximal end-systolic elastance (Emax, index of contractility). Right ventricular end-systolic volume (ESV) and stroke volume (SV) were obtained from CMR and adjusted to body surface area. RHC provided mean PA pressure (mPAP) as a surrogate of right ventricular end-systolic pressure, pulmonary capillary wedge pressure (PCWP) and pulmonary vascular resistance index (PVRI). Ea was calculated as (mPAP − PCWP)/SV and Emax as mPAP/ESV.ResultsEa increased linearly with advancing severity as defined by PVRI quartiles (0.19, 0.50, 0.93 and 1.63 mm Hg/ml/m2, respectively; p