Right ventricular MRI characteristics in patients with borderline pulmonary hypertension

Abstract

Pulmonary hypertension (PH) is defined as a mean pulmonary artery pressure (mPAP) ≥ 25mmHg at right heart catheterization. An mPAP of 21-24mmHg is termed borderline PH. This study investigates cardiac magnetic resonance (CMR) imaging characteristics of patients with borderline PH. Consecutive patients who underwent CMR at 1.5T at a PH centre between April 2012 and January 2016 were identified. Exclusion criteria were non-diagnostic imaging or RHC >48 hours from CMR. All variables were compared between patients with normal mPAP (≤ 20mmHg) and a borderline group (21-24 mmHg) using an independent samples t-test and bilogistic regression. Of 1800 consecutive patients with suspected PH, 128 patients met the inclusion criteria. In the full cohort, large RVEDVI (p Subgroup analysis of patients with connective tissue disease (N=49) revealed raised systolic IVS angle (p=0.048) in borderline patients (N=22). In patients with lung disease (N=60), borderline patients (N=32) had raised RVEDVI (p=0.001), RV mass index (p=0.028) and IVS angle (p=0.05). LHD patients (N=16) with borderline pressures (N=9) had raised RVEDVI (p=0.022) and RV mass index (p=0.041). Patients with thromboembolic disease (N=36) with borderline pressures (N=18) had raised RV mass index (p=0.026). Patients with borderline PH have evidence of RV remodelling but preserved RV functional metrics when compared to patients with normal PA pressure.