Related Experiment Video
Updated: Dec 22, 2025
Point-of-Care Ultrasound for Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation Without Left Ventricular Venting
Published on: January 17, 2025
Emerging trends in mediastinitis: National Veterans Health Administration experience with methicillin-resistant
Charles M Wojnarski1, Yakov Elgudin2, Joseph J Rubelowsky2
1Department of Cardiothoracic Surgery, Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio; Department of Thoracic and Cardiovascular Surgery, Duke University Medical Center, Durham, NC.
Objectives:
Perioperative bacterial decolonization and prophylactic antibiotic therapy at the Veterans Affairs Health Care System have changed over the past decade. Our objectives were to identify associated changes in the microbiology of mediastinitis and to perform a contemporary survival analysis in patients with mediastinitis after isolated coronary artery bypass grafting procedure.
Methods:
From January 2006 to December 2015, 45,323 consecutive patients underwent coronary artery bypass grafting at 83 medical centers. The Veterans Affairs Health Care System nationwide administrative database was queried to identify patients with postoperative mediastinitis and obtain patient-level data. Simple descriptive statistics and multivariable logistic regression were used to analyze microbiologic data and identify risk factors for infection. Poisson regression was used to determine yearly incidence estimates. Cox proportional hazard model identified predictors of long-term survival from date of operation.
Results:
During the study period, 348 patients (0.78%) developed postoperative mediastinitis-with a stable rate of incidence (Cochrane-Armitage test, P = .69). Of patients with microbiologic data, 75.5% of infections (n = 188) were caused by gram-positive and 24.5% (n = 61) gram-negative organisms. The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased during the study period (Cochrane-Armitage test, P = .013). Gram-negative mediastinitis occurred earlier than gram-positive mediastinitis (median, 15.0 vs 25.0 days; P < .0001). Patients with mediastinitis did not have increased 30-day mortality (2.0% vs 1.9%; P = .9), but had worse long-term survival compared with uninfected patients (P < .0001).
Conclusions:
The incidence of methicillin-resistant S aureus mediastinitis has decreased over the past decade. Gram-negative bacteria are responsible for 1 in 4 cases of mediastinitis and infection is diagnosed earlier in the postoperative period than gram-positive mediastinitis. These findings highlight the need for efforts to prevent gram-negative and methicillin-susceptible S aureus mediastinitis.
Insights
The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased over a decade, but gram-negative infections are now more common and diagnosed earlier. Further prevention efforts are needed for gram-negative and methicillin-susceptible S aureus mediastinitis.
Area of Science:
- Cardiovascular Surgery
- Infectious Diseases
- Public Health
Background:
- Changes in perioperative bacterial decolonization and antibiotic therapy have occurred.
- Mediastinitis remains a significant complication after coronary artery bypass grafting (CABG).
Purpose of the Study:
- To analyze changes in the microbiology of mediastinitis over the past decade.
- To assess contemporary survival rates in patients with mediastinitis post-isolated CABG.
Main Methods:
- A retrospective analysis of 45,323 patients undergoing isolated CABG from 2006-2015.
- Utilized the Veterans Affairs Health Care System nationwide administrative database.
- Employed descriptive statistics, logistic regression, Poisson regression, and Cox proportional hazard models.
Main Results:
- The incidence of mediastinitis was stable at 0.78%, with gram-positive organisms causing 75.5% and gram-negative 24.5% of infections.
- Methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis incidence decreased significantly (P=.013).
- Gram-negative mediastinitis occurred earlier postoperatively (median 15 days vs. 25 days for gram-positive), with no increase in 30-day mortality but worse long-term survival.
Conclusions:
- The decline in MRSA mediastinitis is noted, but gram-negative and methicillin-susceptible S aureus mediastinitis require continued prevention strategies.
- Gram-negative bacteria represent a substantial proportion of mediastinitis cases and present earlier.
- Focusing on preventing gram-negative and methicillin-susceptible S aureus infections is crucial for improving patient outcomes.
