Bi-ventricular interplay in patients with systemic sclerosis-associated pulmonary arterial hypertension: Detection by cardiac magnetic resonance

<i>Objectives</i>: Pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc) has a poor prognosis compared to PAH associated with other connective tissue diseases (CTD). The objective of this study was to examine the difference in hemodynamic state between SSc-PAH and other CTD-PAH by performing cardiac magnetic resonance (CMR) imaging. <i>Methods</i>: A single center retrospective analysis was conducted comprising 40 consecutive CTD patients who underwent right heart catheterization and CMR at the same period from January 2010 to October 2015. <i>Results</i>: Thirty-two patients had pre-capillary pulmonary hypertension. Of these, 15 had SSc and 17 had other CTD. CMR measurements, particularly the ratio of right to left end-diastolic volume (RVEDV/LVEDV), correlated well with mean pulmonary arterial pressure (mPAP). Conversely, RVEDV/LVEDV and mPAP correlated differently in SSc and non-SSc patients. In SSc patients, the ratio of RVEDV/LVEDV to mPAP was significantly higher compared to non-SSc patients. In the follow-up study, 2 SSc patients exhibited increased RVEDV/LVEDV in spite of decreased mPAP following treatment. Kaplan–Meier analysis revealed poor prognosis of patients with increased RVEDV/LVEDV following treatment. <i>Conclusions</i>: Our data indicated that altered bi-ventricular interplay detected at CMR may represent SSc-related cardiac involvement and reflect poor prognosis of SSc-PAH.