Differences in mortality in patients undergoing surgery for infective endocarditis according to age and valvular surgery

BACKGROUND: Infective endocarditis (IE) is associated with high mortality. Surgery may improve survival and reduce complications, but the balance between benefit and harm is difficult and may be closely related to age and type of surgical intervention. We aimed to examine how age and type of left-sided surgical intervention modified mortality in patients undergoing surgery for IE. METHODS: By crosslinking nationwide Danish registries we identified patients with first-time IE undergoing surgical treatment 2000-2017. Patients were grouped by age < 60 years, 60-75 years, and ≥ 75 years. Multivariable adjusted Cox proportional hazard analysis was used to examine factors associated with 90-day mortality. RESULTS: We included 1767 patients with IE undergoing surgery, 735 patients < 60 years (24.1% female), 766 patients 60-75 years (25.8% female), and 266 patients ≥75 years (36.1% female). The proportions of patients undergoing surgery were 35.3, 26.9, and 9.1% for patients < 60 years, 60-75 years, and > 75 years, respectively. Mortality at 90 days were 7.5, 13.9, and 22.3% (p < 0.001) for three age groups. In adjusted analyses, patients 60-75 years and patients ≥75 years were associated with a higher mortality, HR = 1.84 (95% CI: 1.48-2.29) and HR = 2.47 (95% CI: 1.88-3.24) as compared with patients < 60 years. Factors associated with 90-day mortality were: mitral valve surgery, a combination of mitral and aortic valve surgery as compared with isolated aortic valve surgery, age, diabetes, and prosthetic heart valve implantation prior to IE admission. CONCLUSIONS: In patients undergoing surgery for IE, mortality increased significantly with age and 1 in 5 died above age 75 years. Mitral valve surgery as well as multiple valve interventions augmented mortality further.