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

Objective: Aortic regurgitation (AR) can lead to pulmonary hypertension (PHT). There is a paucity of data on the prognostic importance of PHT in these patients. We therefore aimed to describe the prevalence and prognostic importance of PHT in such patients.

Methods: In this retrospective study, we analysed the National Echocardiography Database of Australia (data from 2000 to 2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction (LVEF) >50% and with moderate or greater AR were included (n=8392). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes were evaluated (median follow-up of 3.1 years, IQR 1.5-5.7 years).

Results: Subjects were aged 74±14 years and 58.4% (4901) were female. Overall, 1417 (16.9%) had no PHT, and 3253 (38.8%), 2249 (26.9%), 893 (10.6%) and 580 (6.9%) patients had borderline, mild, moderate and severe PHT, respectively. Mean eRVSP was slightly higher in females than males (41±13 vs 39±12 mm Hg, p<0.0001) and increased with age in both sexes. After adjustment for age and sex, the risk of long-term mortality increased as eRVSP increased (adjusted HR (aHR) 1.20, 95% CI 1.06 to 1.36 in borderline PHT, to aHR 3.32, 95% CI 2.85 to 3.86 in severe PHT, p<0.0001). There was a mortality threshold seen from mild PHT onwards (eRVSP 41.36-44.15 mm Hg; aHR 1.41, 95%CI 1.17 to 1.68).

Conclusions: In this large cohort study, we characterise the relationship between AR and PHT in adults. In patients with ≥moderate AR, PHT is associated with a progressive risk of mortality, even at mildly elevated levels.