Risk Factor Analysis for 30-day Mortality After Surgery for Infective Endocarditis.

Background:  Infective endocarditis (IE) remains a challenging disease associated with high mortality. Several scores have been suggested to assess surgical risk. None was sufficiently adequate. We therefore analyzed risk factors for 30-day mortality.

Methods:  A total of 438 consecutive patients had surgery for IE in our department between 2002 and 2020. Patients were divided into two groups, one consisting of 30-day survivors (362 patients; 82.6%) and one of nonsurvivors (76 patients; 17.4%). Logistic regression analysis on pre- and intraoperative risk factors was performed and the groups were compared by univariable analyses.

Results:  Patients in mortality group were older (69 [58, 77] vs. 63 [50, 72] years; p < 0.001), EuroSCORE II was higher (24.5 [12.1, 49.0] vs. 8.95 [3.7, 21.2]; p < 0.001) and there were more females. More frequently left ventricular function (below 30%), preoperative acute renal insufficiency, chronic dialysis, insulin-dependent diabetes mellitus, NYHA-class IV (New York Heart Association heart failure class IV), and cardiogenic shock occurred. Patients in the mortality group were often intensive care unit patients (40.8 vs. 22.4%; p < 0.001) or had a preoperative stroke (26.3 vs. 16.0%; p = 0.033). In the nonsurvivor group Staphylococcus aureus was prevalent. Streptococcus viridans was common in the survivor group as was isolated aortic valve endocarditis (32.9 vs. 17.1%; p = 0.006). Prosthetic valve endocarditis (PVE) and abscesses occurred more often in nonsurvivors. In the logistic regression analysis, female gender, chronic dialysis, cardiogenic shock, and NYHA IV and from intraoperative variables PVE, cardiopulmonary bypass time, and mitral valve surgery were the strongest predictors for 30-day mortality.

Conclusion:  This study indeed clearly indicates that significant risk factors for 30-day mortality cannot be changed. Nevertheless, they should be taken into account for preoperative counselling, and they will alert the surgical team for an even more careful management.