Early Mitral Valve Surgery May Improve Survival in Asymptomatic Mitral Regurgitation: JAMA

A new study published in the Journal of American Medical Association showed that patients with moderate-to-severe mitral regurgitation (MR) had better long-term survival after mitral valve surgery, indicating that the possible advantages of intervention may start before MR reaches the conventionally considered severe range.

Mitral regurgitation occurs when the mitral valve fails to shut correctly, causing blood to flow backward from the left ventricle into the left atrium. Patients with severe MR may develop symptoms, heart enlargement, heart failure, or other consequences in the future, but the best time to do surgery in persons without symptoms, particularly those with intermediate MR, is unknown. Thus, this study checked how the severity of MR impacts long-term survival and if mitral valve surgery is related to increased survival at various disease severity levels.

449 asymptomatic individuals with degenerative mitral regurgitation who were first admitted to the Mayo Clinic between January 1991 and November 2000 were the subjects of this cohort research. Some participants were followed for up to 34 years, with a median follow-up of 26 years. The effective regurgitant orifice area (ERO), a measurement of the aperture through which blood seeps backward, was used to determine the severity of MR. Patients were classified as less than 20 mm², 20–39 mm², or 40 mm² or above based on their ERO. This research assessed long-term survival based on surgical therapy and disease severity in 254 patients (57%) who had mitral valve surgery during follow-up.

Survival gradually declined as MR severity rose in medically treated patients. Patients with an ERO of less than 20 mm² had a five-year survival rate of 88%, those with an ERO of 20–39 mm² had a 5-year survival rate of 72%, and those with an ERO of 40 mm² or more had a 5-year survival rate of just 55%.

Increased mortality risk was independently linked to higher ERO. As MR severity grew, so did the chance of surgery. 18% of patients with an ERO of less than 20 mm², 64% of patients with an ERO of 20–39 mm², and 88% of patients with an ERO of 40 mm² or more underwent surgery within 10 years. Notably, even for individuals in the top range of moderate MR, the survival benefit of surgery became more apparent as ERO approached 30 mm².

Overall, even among patients who did not have symptoms, severe mitral regurgitation was related to increasingly poorer long-term survival rates. Early surgical correction may be beneficial for people with an ERO of 30-39 mm², which is often considered moderate.

Source:

Karadzha, A., Schaff, H. V., Lahr, B. D., Nkomo, V. T., Banivaheb, B., & Enriquez-Sarano, M. (2026). Twenty-five-year follow-up of quantified mitral regurgitation. JAMA Cardiology. https://doi.org/10.1001/jamacardio.2026.2389