A Comparative Analysis of Clinical Variables Associated with Hospitalization in Pulmonary Arterial Hypertension

Abstract

Background Pulmonary arterial hypertension (PAH) is a progressive disease, characterized by pulmonary vascular remodeling and elevation in right ventricular afterload. PAH patients are at an increased risk for right ventricular failure and premature death. Hospitalization is a common precursor to downstream morbidity and mortality in PAH. We sought to characterize clinical variables associated with hospitalization in patients with prevalent PAH. Methods We conducted a retrospective analysis of 124 patients with PAH at our center from 2016 to 2019, comprising demographic data, baseline clinical characteristics, echocardiograms (TTE) and right heart catheterizations (RHC). The cohort was segregated into two groups based on whether patients were admitted to the hospital. A comparative analysis of hospitalized (n=61) vs non-hospitalized (n=63) patients was performed. Regression modeling determined predictors of admission. Results 82% of patients hospitalized were related to cardiac complications of PAH whereas 18% were non cardiac hospitalizations. 67% of cardiac admissions were related to exacerbation of right heart failure or cardiogenic shock, Other causes included acute pulmonary embolism (3%), cardiac surgery (3%), chest pain (2%), supraventricular arrhythmias (5%), and AV block (2%). Hospitalized patients had significantly higher proportions of patients with age >60 years (54 vs 36%), NYHA class III symptoms (57 vs 39%), hypertension (HTN) (61 vs 40%), tricuspid regurgitation (54 vs 33%), baseline oxygen requirement (34 vs 16%), pericardial effusion (21 vs 6%) on TTE and higher mean right atrial (RA) pressure by RHC (8 vs 6 mmHg). Furthermore, admitted patients had significantly lower right ventricular fractional area change (23 vs 34%), and tricuspid annular plane systolic excursion (TAPSE) (18 vs 21mm) by TTE. On multivariate logistic regression analysis, NYHA class III [OR(CI): 12 (2-62), p=0.004], HTN [OR(CI): 4 (1.1-16.6), p=0.04] were associated with higher odds of hospitalization whereas high TAPSE was associated with lower odds of hospitalization [OR(CI): 0.87 (0.8-0.9), p=0.03]. Conclusion Accurate assessment of risk factors associated with hospitalization in PAH is important as hospitalization is a sentinel event associated with downstream mortality in PAH patients. Our study provides insights into predictors of hospitalization in PAH patients and may help with regards to risk stratification in the outpatient setting.