Prevalence of pulmonary hypertension in mitral regurgitation and its influence on outcomes

Abstract

Abstract Background Pulmonary hypertension (PHT) commonly co-exists with significant mitral regurgitation (MR), but its prevalence and prognostic importance has not been well documented. Purpose In a large cohort of adults with ≥moderate MR, we aimed to describe the prevalence and severity of PHT and assess its influence on outcomes. Methods We analysed the National Echocardiography Database of Australia (data from 2000-2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction (LVEF) >50% and with moderate or greater MR were included (n= 9683). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes were evaluated (median follow-up of 3.2 years, interquartile range 1.3-6.2years). Results Subjects were aged 76±12years and 62.6% (6038) were female. Overall, 959 (9.9%) had no PHT; and 2952 (30.5%), 3167 (32.7%), 1588(16.4%) and 1017 (10.5%) patients had borderline, mild, moderate and severe PHT respectively. A "typical left heart disease" phenotype was identified with worsening PHT, showing rising E:e’, right and left atrial sizes increasing progressively, from no PHT to severe PHT (p<0.0001, for all). With increasing PHT severity, 1- and 5-year actuarial mortality increased from 8.5% and 39.7%, and from to 33.0% and 79.8% respectively (p<0.0001). Similarly, adjusted survival analysis showed the risk of long-term mortality progressively increased with higher eRVSP levels (adjusted hazard ratio (aHR) 1.20, 95% confidence interval 1.04-1.38 in borderline PHT, to aHR2.86, 95%CI 2.48-3.31 in severe PHT, p<0.0001) (Figure 1). A mortality inflection was apparent at an eRVSP level >34.00mmHg (HR1.27, CI1.00-1.36) (Figure 2). Conclusions In this large study we characterise the close but incompletely understood relationship between significant MR and complicating PHT. Mortality increases as PHT becomes more severe from an eRVSP of approximately 34mmHg onwards.Adjusted Risk for All-Cause MortalityThreshold for Mortality