Recurrent infective endocarditis versus first-time infective endocarditis after heart valve surgery.

OBJECTIVE

Infective endocarditis (IE) may require heart valve surgery. It is well known that heart valve surgery itself and previous IE predispose to IE. However, data are sparse on whether the risk of IE is different among patients undergoing valve surgery due to IE and other causes (i.e. recurrent vs. first-time IE).

METHODS

Using Danish nationwide registries, patients undergoing left-sided heart valve surgery in the course of an IE hospitalization (1996-2017) were identified and matched with controls undergoing left-sided heart valve surgery due to another cause than IE in a 1:1 ratio. Patients were stratified according to type of surgical valve intervention and affected valve. The comparative risk of recurrent vs. first-time IE was assessed by cumulative incidence curves and multivariable Cox regression analyses.

RESULTS

The study population comprised 971 patients with a first-time admission for IE requiring heart valve surgery matched with 971 controls undergoing heart valve surgery due to other causes than IE. The risk of recurrent IE was significantly higher than the risk of first-time IE following heart valve surgery (5.5% and 3.0% by 10 years, hazard ratio (HR) 1.66, 95% confidence interval (CI) 1.02-2.70). The risk of IE recurrence was not significantly different comparing valve replacement and valve repair (5.5% and 5.3%, respectively, HR 1.60, 95% CI 0.71-3.60). Yet, the risk of IE recurrence was significantly higher among patients with biological versus mechanical prostheses (6.3% and 4.6%, respectively, HR 2.00, 95% CI 1.02-3.70).

CONCLUSIONS

Following heart valve surgery, the risk of recurrent IE was significantly higher than the risk of first-time IE.