Four factors – younger patient age, male sex, diabetes, and moderate to severe residual aortic regurgitation – are associated with a significantly increased risk of infective endocarditis after transcatheter aortic valve replacement, according to a report published online Sept. 13 in JAMA.

Until now, data pertaining to endocarditis following TAVR “have been limited to case reports and relatively small series with limited follow-up,” said Ander Regueiro, MD, of Laval University, Quebec City, and his associates.

They performed a retrospective analysis of data in a large international registry of TAVR cases to better characterize post-TAVR endocarditis.

Dr. Regueiro and his colleagues focused on 20,006 TAVR procedures done at 47 medical centers in Europe, North America, and South America during a 10-year period. The median time to symptom onset was 5.3 months after the procedure.

Infective endocarditis was definitively diagnosed in 250 of these cases. This incidence is similar to that reported for endocarditis following surgical aortic valve replacement, indicating that TAVR is no less predisposing to endocarditis despite being a less invasive approach.

The mean age of patients who developed post-TAVR endocarditis was 78.9 years, compared with 81.8 years for those who did not (HR, 0.97). The reason for this association is unclear, but it is possible that younger patients chosen for TAVR because of their prohibitive surgical risk carry a higher burden of comorbidity than do older patients. Similarly, 62% of endocarditis cases arose in men (HR, 1.69), and sex differences in comorbid conditions may explain the higher risk among men.

More patients who developed endocarditis had diabetes (41.7%), compared with those who did not develop endocarditis (30%), for an HR of 1.52. And patients who had moderate to severe residual aortic regurgitation after TAVR also were at much higher risk for endocarditis than were those who did not (HR, 2.05), the investigators noted ( JAMA. 2016 Sep 13;316[10]:1083-92 ).

In contrast, factors that were not associated with endocarditis risk included chronic pulmonary disease, type of valve (self-expandable or balloon-expandable), and setting of the procedure (catheterization lab vs. operating room).

The bacteria that most commonly caused infective endocarditis were Enterococci species (24.6% of cases), Staphylococcus aureus (23.8%), and coagulase-negative staphylococci (16.8%). This should be taken into consideration when selecting antibiotics for prophylaxis before TAVR and when choosing empirical antibiotics for treatment while waiting for blood culture results, wrote Dr. Regueiro and his associates.

“This information may help clinicians identify patients at higher risk [for endocarditis] and aid in implementing appropriate preventive measures,” they noted.

This study was supported by a grant from the Alfonso Martin Escudero Foundation. Dr. Regueiro reported having no relevant financial disclosures; his associates reported ties to numerous industry sources.