Mortality Associated with Surgical Site Infections Following Cardiac Surgery: Insights from the International ID-IRI Study

Abstract

Objectives: Surgical site infections (SSIs) after cardiac surgery increase morbidity and mortality rates. This multicenter study aimed to identify mortality risk factors associated with SSIs after heart surgery. Methods: Conducted from January to March 2023, this prospective study included 167 patients aged >16 years with post-heart surgery SSIs. The primary focus was the 30-day mortality. Univariate analysis and multivariate logistic regression utilizing the backward elimination method were used to establish the final model. Results: Several factors significantly correlated with mortality. These included urinary catheterization (odds ratio OR 14.197; 90% confidence interval CI 12.198-91.721), emergent surgery (OR 8.470 90% CI 2.028-35.379), valvular replacement (OR 4.487 90% CI 1.001-20.627), higher quick Sequential Organ Failure Assessment scores (OR 3.147 90% CI 1.450-6.827), advanced age (OR 1.075 90% CI 1.020-1.132), and postoperative re-interventions within 30 days after SSI (OR 14.832 90% CI 2.684-81.972). No pathogens were isolated from the wound cultures of 53 (31.7%) patients. A total of 43.1% of SSIs (n = 72) were due to gram-positive microorganisms, whereas 27.5% of cases (n = 46) involved gram-negatives. Among the gram-positive bacteria, Staphylococci (n = 30, 17.9%) were the predominant microorganisms, whereas Klebsiella (n = 16, 9.6%), Escherichia coli (n = 9, 5.4%), and Pseudomonas aeruginosa (n = 7, 4.2%) were the most prevalent. Conclusions: To mitigate mortality after heart surgery, stringent infection control measures and effective surgical antisepsis are crucial, particularly, in the elderly. The clinical progression of the disease is reflected by the quick Sequential Organ Failure Assessment score and patient re-intervention, and effective treatment is another essential component of SSI management.