Effects of Concomitant CABG on Outcomes in Veterans Who Require Surgery for Endocarditis.

BACKGROUND: Infective Endocarditis (IE) is a complicated disease frequently accompanied by coronary artery disease (CAD) though no clear guidelines exist for when concomitant revascularization should be undertaken once valve surgery is indicated. Data on this topic within the United States (US) Veteran population, who have unique healthcare needs when compared to the civilian population, is sparse. We investigated the impact of concomitant coronary artery bypass grafting (CABG) on morbidity and mortality in US Veterans requiring surgical management of IE. METHODS: We identified 489 patients who underwent surgical management of IE between January 1 2010 and December 31 2020 at any of 43 Veterans Affairs (VA) cardiac surgery centers in the US. Patients were stratified based on who underwent concomitant CABG at the time of operation. Primary outcomes included the occurrence of postoperative myocardial infarction (MI), stroke, or mortality. Continuous variables were compared using independent t-tests or Mann Whitney U tests, and categorical variables were compared using the Chi square test. Cox proportional-hazard models were used to calculate risk for primary outcomes based on group. RESULTS: 61 patients (12.5%) underwent concomitant CABG for CAD. After adjusting for significant covariates, patients who underwent CABG had a higher long-term risk of MI (adjusted hazard ratios (aHR) 2.37, 95% CI: 1.29-4.35, p = 0.005) and higher risk of MI at 30-days (aHR 2.34, 95% CI: 1.06-5.19, p = 0.035). Concomitant CABG was not associated with long-term stroke or death, 30-day stroke or death, or perioperative complications. On sub-analysis of patients with moderate to severe CAD, rates of MI were higher in the CABG group at 30 days (25.9 vs. 3.4%, p = 0.016) and 1 year (33.3 vs. 3.4%, p = 0.004), though not long-term. The mean number of grafts was 1.51 ± 0.76, with only one graft performed in 65.6% (40/61) of patients. CONCLUSIONS: Concomitant CABG at the time of operation for IE was associated with increased risk of MI at 30-day and long-term, though most CABGs involved a low number of grafts. It was not associated with 30-day stroke or death, long term stroke or death, or perioperative complications. The optimal treatment of CAD noted during preoperative evaluation for veterans undergoing surgery for IE remains unclear.

Microbiology of Infective Endocarditis in United States Veterans - Association Between Causative Organism and Short- and Long-Term Outcomes.

BACKGROUND: Previous studies have elucidated the relationship between causative organism and outcomes in infective endocarditis, however this relationship has not been studies in United States Veterans. The aim of this manuscript is to evaluate the association between causative organism and short-term and long-term outcomes in United States (US) Veterans with infective endocarditis (IE) requiring surgical management between 2010-2020. METHODS: We analyzed 489 patients with surgically treated IE from the Veterans Affairs (VA) Surgical Quality Improvement Program and the VA Informatics and Computing Infrastructure databases. Patients were divided into groups using causative organism identified from blood or intraoperative cultures - Staphylococcus, Streptococcus, Gram-negative rods, Enterococcus, Polymicrobial, and Unknown/Culture Negative. Other identified organisms were excluded from analysis. Cox proportional hazard models were used to calculate risk for stroke/transient ischemic attack (TIA), myocardial infarction (MI), and death based on group. The models were adjusted for covariates using backward elimination. Continuous variables were compared using ANOVA or Kruskal-Wallis H tests, and categorical variables were compared using Chi square tests. RESULTS: Mean follow-up was 4.0 ± 6.3 years. Gram negative rods (GNRs) were associated with greater risk of long-term mortality (adjusted hazard ratios (aHR) 2.15, 95% CI: 1.20-3.86, p = 0.01). Enterococcus was associated with long-term risk of MI (aHR 2.05, 95% CI: 1.07-3.94, p = 0.03). Resistant organisms, such as methicillin-resistant staphylococcus aureus, were associated with long-term risk of MI (aHR 2.51, 95% CI: 1.14-5.45, p = 0.02). Polymicrobial infections were associated with greater risk of perioperative complications, including prolonged mechanical ventilation (48 hrs) (aHR 1.76, 95% CI: 1.05-2.97, p = 0.034), tracheostomy (aHR 5.64, 95% CI: 2.35-13.55, p < 0.001), and prolonged ICU stay (5 days) (aHR 1.39, 95% CI: 1.01-1.91, p = 0.043). CONCLUSIONS: In US Veterans, polymicrobial infections had notably worse perioperative outcomes but similar long-term outcomes in comparison to monomicrobial infections. GNR infections were associated with increased long-term mortality. Enterococcus and resistant organisms were associated with increased long-term risk of MI. Polymicrobial infections were associated with greater risk of perioperative complications, including prolonged mechanical ventilation, tracheostomy, and prolonged ICU stay.

Long-Term Mortality Risk According to Cardiorespiratory Fitness in Patients Undergoing Coronary Artery Bypass Graft Surgery.

The aim of this study was to evaluate the association between cardiorespiratory fitness (CRF) and long-term survival in United States (US) Veterans undergoing CABG. We identified 14,550 US Veterans who underwent CABG at least six months after completing a symptom-limited exercise treadmill test (ETT) with no evidence of cardiovascular disease. During a mean follow-up period of 10.0 ± 5.4 years, 6502 (43.0%) died. To assess the association between CRF and risk of mortality, we formed the following five fitness categories based on peak workload achieved (metabolic equivalents or METs) prior to CABG: Least-Fit (4.3 ± 1.0 METs (n = 4722)), Low-Fit (6.8 ± 0.9 METs (n = 3788)), Moderate-Fit (8.3 ± 1.1 METs (n = 2608)), Fit (10.2 ± 0.8 METs (n = 2613)), and High-Fit (13.0 ± 1.5 METs (n = 819)). Cox proportional hazard models were used to calculate risk across CRF categories. The models were adjusted for age, body mass index, race, cardiovascular disease, percutaneous coronary intervention prior to ETT, cardiovascular medications, and cardiovascular disease risk factors. P-values < 0.05 using two-sided tests were considered statistically significant. The association between cardiorespiratory fitness and mortality was inverse and graded. For every 1-MET increase in exercise capacity, the mortality risk was 11% lower (HR = 0.89; CI: 0.88-0.90; p < 0.001). When compared to the Least-Fit category (referent), mortality risk was 22% lower in Low-Fit individuals (HR = 0.78; CI: 0.73-0.82; p < 0.001), 31% lower in Moderate-Fit individuals (HR = 0.69; CI: 0.64-0.74; p < 0.001), 52% lower in Fit individuals (HR = 0.48; CI: 0.44-0.52; p < 0.001), and 66% lower in High-Fit individuals (HR = 0.34; CI: 0.29-0.40; p < 0.001). Cardiorespiratory fitness is inversely and independently associated with long-term mortality after CABG in Veterans referred for exercise testing.