Mitral valve replacement versus repair and long-term risk of infective endocarditis: a nationwide study

Abstract

Abstract Background There is a paucity of data regarding mitral valve (MV) repair versus MV replacement and the associated risk of infective endocarditis (IE). Further research is needed to optimise patient selection and determine the importance of using prophylactic antibiotics. Purpose To examine the long-term risk of IE in patients undergoing MV repair, compared with a matched population of patients undergoing MV replacement as well as the background population. Methods All patients undergoing MV repair from 2000 to 2020 with no history of IE were identified using Danish nationwide registries. Those patients were matched to patients undergoing MV replacement in a 1:1 ratio as well as the background population in a 1:4 ratio based on age, sex, and year of procedure. The Aalen-Johansen estimator and multivariable Cox regression models were used to examine the long-term risk of IE. Results After matching, the study population included 1,797 patients undergoing MV replacement, 1,797 undergoing MV repair, and 7,188 matched controls from the background population. The median age of the study population was 67.8 years (percentile[p]25-p75: 57.8-74.7), and 45.1% were females. Patients with MV replacement were significantly more comorbid, compared with patients with MV repair and the control group, which included ischaemic heart disease, heart failure, atrial fibrillation, stroke, diabetes, chronic renal disease, and chronic obstructive pulmonary disease. During a median follow-up of 7.7 years (p25-p75: 4.0-13.5), 134 (7.5%) with MV replacement, 57 (3.2%) patients with MV repair, and 27 (0.38%) in the control group were hospitalised with IE. The median follow-up time from date of procedure to IE admission was 3.5 years (p25-p75: 0.82-7.1) in the MV replacement group, 2.4 years (p25-p75: 0.61-6.6) in the MV repair group, and 8.2 years (p25-p75: 5.3-12.4) in the control group. In patients with MV replacement, MV repair, and the control group, the 1-year cumulative incidences of IE (Figure) were 7.5% (95% CI: 6.3-8.7%), 3.2% (95% CI: 2.4-4.1%), and 0.38% (95% CI: 0.25-0.54%), respectively. The 10-year cumulative incidences of IE (Figure) were 9.4% (95% CI: 7.9-11.1%), 3.9% (95% CI: 3.0-5.0%), and 0.56% (95% CI: 0.38-0.82%) in patients with MV replacement, MV repair, and the control group, respectively. After multivariable adjustment, MV replacement was associated with an increased 10-year rate of IE, compared with MV repair (hazard ratio 2.4 [95% CI: 1.8-3.3]), while the control group was associated with a lower 10-year rate, compared with MV repair (hazard ratio 0.14 [95% CI: 0.085-0.23]). Conclusion In this nationwide study, MV replacement was associated with a twofold increased 10-year rate of infective endocarditis, while matched controls from the background population were associated with a significantly lower 10-year rate of infective endocarditis, compared with MV repair.Figure