Abstract 17125: Cardiovascular Mortality Defines Severe RV Enlargement in Pre-Capillary Pulmonary Hypertension by a RV to LV Volume Ratio >2.0

Abstract

Introduction: Cardiac magnetic resonance imaging (CMR) is emerging as a non-invasive, prognostic tool in pulmonary arterial hypertension (PAH). The right ventricular (RV) end diastolic volume (EDV) to left ventricular (LV) EDV ratio measured by CMR is a parameter to evaluate RV size in relationship to the patient’s own LV and determine severity of dilation in patients with pulmonary arterial hypertension (PAH). An RVEDV/LVEDV greater than 2.3 has been proposed as a cutoff for severe RV enlargement in PAH based on mortality risk 1 . This study aims to confirm this cutoff in pre-capillary (pc) pulmonary hypertension (PH) patients using CMR and mortality data from two additional cohorts. Materials and Methods: In this retrospective study, we analyzed primary outcome cardiovascular mortality and CMR parameters in a database of patients from 2014 to 2021 with pcPH (mean pulmonary artery pressure > 20mmHg, PCWP<15 mmHg, WU≥ 3) determined by right heart catheterization (RHC) from Ohio State University (OSU) (n=42) and West China Hospital (WCH) (n=58). Patients with congenital heart disease, ischemic heart disease, valvular heart disease (moderate to severe AS, AR, MS, or MR), ECV <20 or >28, and WHO group II PH were excluded from the analysis. The optimal cutoff values to classify severe RV enlargement by RVEDV/LVEDV was determined by a receiver operating characteristic (ROC) curve using cardiovascular mortality. Results: The event rates for cardiovascular mortality among the OSU and WCH cohorts were 14/42 and 14/58, respectively. Altmayer identified the optimal cut-off as 2.32 (sensitivity = 87.5%; specificity = 87.0%, AUC=82%) 1 . An RVEDV/LVEDV of 2.01 was the optimal cutoff to predict cardiovascular mortality using the ROC analysis from the OSU cohort (sensitivity= 71.4%, specificity = 82.1%, AUC 80.1%). It was 2.46 from the WCH cohort (sensitivity = 64.3%, specificity = 86.3%, AUC 77.7%). When data from the OSU and WCH cohort were combined, the optimal cutoff was 2.1 (sensitivity = 71%, specificity = 72%, AUC 77.1%). Conclusions: Using data from three different populations of pcPH patients, an RVEDV/LVEDV of at least >2.0 can be used to partition severe RV dilation using cardiovascular mortality.