Abstract 13989: Duration of Interventricular Septal Shift Predicts Clinical Outcome in Patients With Precapillary Pulmonary Hypertension: A CMR Study

Abstract

Introduction: Right ventricular pressure overload results in interventricular septal (IVS) shift towards the left ventricle in patients with precapillary pulmonary hypertension (pPH). Hypothesis: The duration of IVS shift towards left ventricle during the cardiac cycle, as expressed by a novel marker called curvature duration index (CDi), predicts clinical outcome in pPH patients. Methods: This was a prospective study. All patients underwent cardiac magnetic resonance (CMR, Avanto Siemens 1,5T). CMR parameters of right ventricular function and dimensions were assessed. CDi (duration of IVS shift towards left ventricle x 100/cardiac cycle duration) was defined in the short-axis view at the level of papillary muscles (Figure 1). Time from enrollment to clinical failure (hospitalization due to pPH, initiation of parenteral prostanoid therapy, atrial septostomy or death) was recorded. Results: Our study included 36 consecutive patients (28 women, mean age 50.6±13.8 years) with pPH. Over a median follow-up period of 20.4 months (IQR 16.3-24.6 months) 14 clinical events were observed. In Cox proportional hazard analysis, only baseline CDi was significantly related to the composite event (HR 1.05, 95% CI 1.01-1.08, p=0.016). ROC curve analysis showed that the optimal cut-off value of CDi which predicted events was 66.7%. Kaplan-Meier survival analysis showed that CDi ≥66.7% was associated with a 9-fold increased risk for clinical failure (Figure 2). Conclusions: Ventricular septal shift towards left ventricle lasting for more than the 2/3 of the cardiac cycle is associated with worse prognosis in pPH.