Natural history of aortic valve disease after rheumatic mitral valve surgery: implications for concomitant aortic intervention

Rheumatic heart disease (RHD) frequently affects both mitral and aortic valves. While mitral valve replacement (MVR) is often prioritized, the natural history of coexisting aortic valve disease particularly when mild or moderate is less well understood. The objective of this study is to assess the progression of aortic stenosis (AS) and aortic insufficiency (AI) in patients undergoing isolated MVR for rheumatic mitral disease. We conducted a single-center retrospective cohort study involving 403 adult patients with rheumatic mitral valve disease who underwent isolated MVR at Rajaie Cardiovascular Medical and Research Center between 2010 and 2022. Patients with a history of aortic valve replacement or early postoperative mortality (defined as death within 30 days of surgery) were excluded. Serial transthoracic echocardiography was performed at baseline, 3 months postoperatively, and annually thereafter, with a mean follow-up duration of 78 months. We evaluated baseline and longitudinal changes in the severity of aortic stenosis (AS) and aortic insufficiency (AI), as well as alterations in left ventricular function and pulmonary artery pressures over time. The severity of aortic valve disease was classified according to the American Heart Association (AHA) 2020 and European Society of Cardiology (ESC) 2025 guidelines. At baseline, 9.2% had AS (6.2% mild, 3.0% moderate) and 67% had AI (57.6% mild, 9.4% moderate). During our follow up among patients with mild AS, we observed sever AS is 20% progressing to severe AS, compared with 41.7% progressing to moderate AS. For AI, we observed 3.0% progression to severe AI for patients with mild baseline disease and is 7.8% for patients with moderate baseline disease. Baseline aortic valve lesion severity independently predicted progression (HR 4.2, 95% CI 1.9–9.1, p < 0.001). No other clinical or echocardiographic parameters were significant. Survival analysis showed higher cumulative progression rates among those with baseline lesions (p < 0.001). Baseline aortic valve involvement predicts subsequent deterioration after MVR. Routine prophylactic AVR is not supported for mild AI, but moderate AS warrants closer follow-up and individualized surgical consideration. Larger, prospective studies are needed to refine risk prediction for concomitant aortic intervention.