Contemporary epidemiology and outcomes in recurrent infective endocarditis.

Objective: Recurrent infective endocarditis (IE) is a major complication of patients surviving a first episode of IE. This study sought to analyse the current state of recurrent IE in a large contemporary cohort.

Methods: 1335 consecutive episodes of IE were recruited prospectively in three tertiary care centres in Spain between 1996 and 2015. Episodes were categorised into group I (n=1227), first-IE episode and group II (n=108), recurrent IE (8.1%). After excluding six patients, due to lack of relevant data, group II was subdivided into IIa (n=87), reinfection (different microorganism), and IIb (n=15), relapse (same microorganism within 6 months of the initial episode).

Results: The cumulative burden and incidence of recurrence was slightly lower in the second decade of the study (2006-2015) (7.17 vs 4.10 events/100 survivors and 7.51% vs 3.82, respectively). Patients with reinfections, compared with group I, were significantly younger, had a higher frequency of HIV infection, were more commonly intravenous drug users (IVDU) and prosthetic valve carriers, had less embolic complications and cardiac surgery, with similar in-hospital mortality. IVDU was found to be an independent predictor of reinfection (HR 3.92, 95% CI 1.86 to 8.28).In the relapse IE group, prosthetic valve endocarditis (PVE) and periannular complications were more common. Among patients treated medically, those with PVE had a higher relapse incidence (4.82% vs 0.43% in native valve IE, p=0.018). and PVE were independent predictors of relapse (HR 3.14, 95% CI 1.11 to 8.86 and 3.19, 95% CI 1.13 to 9.00, respectively) and in-hospital-mortality was similar to group I. Three-year all-cause mortality was similar in recurrent episodes compared with single episodes.

Conclusion: Recurrent IE remains a frequent late complication. IVDU was associated with a fourfold increase in the risk of reinfection. PVE treated medically and infections caused by increased the risk of relapse. In-hospital and long-term mortality was comparable among groups.