Can prosthesis type influence the recurrence of infective endocarditis after surgery for native valve endocarditis? A propensity weighted comparison.

OBJECTIVES: Our goal was to investigate whether the incidence of valve-related adverse events might be different depending on the valve substitute after valve replacement for left-sided native valve endocarditis. METHODS: We assessed the long-term freedom from recurrence, reoperation and survival of 395 patients who had valve replacements for native valve endocarditis (314 mechanical vs 81 biological). Age <18 years, reoperation, prosthetic endocarditis, right valve involvement, valve repair and homograft implants were the main exclusion criteria. The balance between the 2 groups was addressed by weighting the results on the inverse of the propensity score. RESULTS: After inverse probability of treatment weighting (IPTW), freedom from recurrence of infective endocarditis was not significantly different (mechanical 84.1 ± 3.2% vs 50.6 ± 21.7%; P = 0.29) nor was freedom from reoperation different (mechanical 85.7 ± 3.1% vs biological 50.9 ± 21.9%; P = 0.29). Excluding competing deaths, patients receiving a bioprosthesis had a similar subdistribution hazard of the above end points compared to recipients of a mechanical valve [recurrence IPTW: hazard ratio (HR) 1.631, 95% confidence interval (CI) 0.756-3.516; P = 0.21; reoperation IPTW-HR 1.737, 95% CI 0.780-3.870; P = 0.18]. Mechanical valves were associated with improved long-term survival (34.9 ± 5.8% vs 10.5 ± 7.4% at 30 years; P = 0.0009; in particular: aortic valve subgroup 41.6 ± 9.3% vs 10.1 ± 8.2%; P < 0.0001), although the hazard of cardiovascular mortality did not favour either valve type (IPTW: HR 1.361, 95% CI 0.771-2.404; P = 0.29). CONCLUSIONS: Our analysis showed a clinical trend in favour of mechanical valves as valve substitutes for native valve endocarditis, especially in the aortic position. In view of long-term freedom from adverse events, the choice of the valve type should be tailored according to patient characteristics and specific clinical conditions.

Topical rifampicin for prevention of deep sternal wound infections in patients undergoing coronary artery bypass grafting.

Deep sternal wound infections (DSWI), although an infrequent complication, significantly impair postoperative outcomes after coronary artery bypass grafting (CABG) surgery. Among several preventive strategies, topical antibiotic therapy immediately before sternal closure has been strongly advocated. In this retrospective analysis, the incidence of DSWI in 517 patients undergoing isolated CABG and receiving rifampicin irrigation of mediastinum, sternum and suprasternal tissues was compared to an historical consecutive cohort of 448 patients. To account for the inherent selection bias, a 1:1 propensity matched analysis was performed. Patients receiving topical rifampicin experienced significantly less occurrence of postoperative DSWI (0.2% vs 2.5%, p = 0.0016 in the unmatched analysis; 0.3% vs 2.1%, p = 0.0391 in the matched analysis). Intensive care unit stay, hospital stay, and operative mortality were similar between groups. This study shows that topical rifampicin in combination with commonly prescribed preventative strategies significantly reduces the incidence of DSWI to less than 0.3% in unselected patients undergoing a full median sternotomy for CABG. Further studies, including a larger number of patients and with a randomization design, would establish the potential preventative role of topical rifampicin in reducing the occurrence of DSWI.