Mitral valve (MV) replacement is associated with a 3.5-fold higher long-term risk of infective endocarditis compared with MV repair and with patients at moderate risk of infective endocarditis, according to a study published July 11 in EHJ.

Amna Alhakak, MD, et al., analyzed Danish nationwide registry data (2000–2020) to determine the risk of infective endocarditis in 1,220 patients undergoing MV replacement, 3,239 undergoing MV repair, and 209,517 at moderate risk of infective endocarditis. Patients with cardiac implantable electronic devices, congenital heart valve anomalies, hypertrophic cardiomyopathy, rheumatic heart disease or nonrheumatic degenerative valve disease comprised the moderate-risk group.

Results showed that the 10-year cumulative incidence of first-time infective endocarditis was 6.1% (95% CI, 4.8%-7.7%) after MV replacement, 1.6% (95% CI, 1.1%-2.1%) after MV repair, and 1.7% (95% CI, 1.6%-1.7%) in the moderate-risk group. Similarly, after multivariable adjustment, compared with the moderate-risk group, MV replacement was associated with a significantly higher risk of infective endocarditis (hazard ratio [HR], 3.52; 95% CI, 2.73-4.52), whereas MV repair was not associated with an increased infective endocarditis risk (HR, 0.76; 95% CI, 0.56-1.04).

The authors conclude that moving forward, more studies are warranted "to determine whether MV replacement and repair should be treated equally with antibiotic prophylaxis."

In an accompanying editorial comment , Daniele Giacoppo, MD, writes that this study "represents an outstanding opportunity to define the contemporary risk of [infective endocarditis] after MV repair and MV replacement, providing insights for implementing preventive strategies and surveillance programs for patients who have undergone prosthetic MV replacement and promoting new investigations on preventive treatment requirements between patients who have undergone MV repair and ... replacement."