Risk stratification tool for all surgical site infections after coronary artery bypass grafting.

OBJECTIVE: To develop a risk score for surgical site infections (SSIs) after coronary artery bypass grafting (CABG). DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: A derivation sample of 7,090 consecutive isolated or combined CABG patients and 2 validation samples (2,660 total patients). METHODS: Predictors of SSIs were identified by multivariable analyses from the derivation sample, and a risk stratification tool (additive and logistic) for all SSIs after CABG (acronym, ASSIST) was created. Accuracy of prediction was evaluated with C-statistic and compared 1:1 (using the Hanley-McNeil method) with most relevant risk scores for SSIs after CABG. Both internal (1,000 bootstrap replications) and external validation were performed. RESULTS: SSIs occurred in 724 (10.2%) cases and 2 models of ASSIST were created, including either baseline patient characteristics alone or combined with other perioperative factors. Female gender, body mass index >29.3 kg/m2, diabetes, chronic obstructive pulmonary disease, extracardiac arteriopathy, angina at rest, and nonelective surgical priority were predictors of SSIs common to both models, which outperformed (P < .0001) 6 specific risk scores (10 models) for SSIs after CABG. Although ASSIST performed differently in the 2 validation samples, in both, as well as in the derivation data set, the combined model outweighed (albeit not always significantly) the preoperative-only model, both for additive and logistic ASSIST. CONCLUSIONS: In the derivation data set, ASSIST outperformed specific risk scores in predicting SSIs after CABG. The combined model had a higher accuracy of prediction than the preoperative-only model both in the derivation and validation samples. Additive and logistic ASSIST showed equivalent performance.

Isolated left atrial cryoablation of atrial fibrillation in conventional mitral valve surgery.

BACKGROUND: Recent trends of surgery for atrial fibrillation (AF) are towards more safe and effective energy sources, as well as to simplified sets of atrial lesions. METHODS: One hundred eighteen (mean age, 67.4 ± 9.2 years) selected patients with paroxysmal/persistent AF and mitral valve (MV) disease underwent cryoablation of AF combined with conventional (not via mini-thoracotomy) MV surgery; the lesion set was limited to only the left atrium. Multivariable analyses identified predictors of cardiac rhythm at hospital discharge and follow-up. RESULTS: There were 7 (5.9%) hospital deaths; 33 (28%) patients were discharged on AF. Higher values of preoperative left atrial volume index (odds ratio [OR] = 1.07, 95% confidence interval [95%CI]: 1.01-1.13) and mixed etiology of MV disease (OR = 4.19, 95%CI: 1.23-14.2) were predictors of hospital discharge on AF. Seventy-four (66.7%) patients were on stable sinus rhythm at follow-up (median period, 6.6 years); the 1, 5, and 10-year nonparametric estimates of adjusted freedom from AF were 98.1%, 89.2% and 45.6%, respectively. Higher values of preoperative systolic pulmonary artery pressure (hazard ratio [HR] = HR = 1.04, 95%CI: 1.01-1.08) and AF at hospital discharge (HR = 4.14, 95%CI: 1.50-11.4) were predictors of AF at follow-up. CONCLUSIONS: During conventional MV surgery, a cryo-lesion set limited to only the left atrium may give good, immediate and long-term results. Left atrial dilation and mixed etiology of MV disease were predictors of hospital discharge on AF. Preoperative pulmonary hypertension and AF at discharge combined with an increased risk of AF at follow-up.

Validation and Performance Comparison of Two Scoring Systems Created Specifically to Predict the Risk of Deep Sternal Wound Infection after Bilateral Internal Thoracic Artery Grafting.

Background: The Gatti and the bilateral internal mammary artery (BIMA) scores were created to predict the risk of deep sternal wound infection (DSWI) after bilateral internal thoracic artery (BITA) grafting. Methods: Both scores were evaluated retrospectively in two consecutive series of patients undergoing isolated multi-vessel coronary surgical procedures-i.e., the Trieste (n = 1,122; BITA use, 52.1%; rate of DSWI, 5.7%) and the Besançon cohort (n = 721; BITA use, 100%; rate of DSWI, 2.5%). Baseline patient characteristics were compared between the two validation samples. For each score, the accuracy of prediction and predictive power were assessed by the area under the receiver-operating characteristic curve (AUC) and the Goodman-Kruskal gamma coefficient, respectively. Results: There were significant differences between the two series in terms of age, gender, New York Heart Association functional class, chronic lung disease, left ventricular function, surgical priority, and the surgical techniques used. In the Trieste series, accuracy of prediction of the Gatti score for DSWI was higher than that of the BIMA score (AUC, 0.729 vs. 0.620, p = 0.0033). The difference was not significant, however, in the Besançon series (AUC, 0.845 vs. 0.853, p = 0.880) and when only BITA patients of the Trieste series were considered for analysis (AUC, 0.738 vs. 0.665, p = 0.157). In both series, predictive power was at least moderate for the Gatti score and low for the BIMA score. Conclusions: The Gatti and the BIMA scores seem to be useful for pre-operative evaluation of the risk of DSWI after BITA grafting. Further validation studies should be performed.

The fate of patients having deep sternal infection after bilateral internal thoracic artery grafting in the negative pressure wound therapy era.

BACKGROUND: Late survival of patients having deep sternal wound infection (DSWI) after bilateral internal thoracic artery (BITA) grafting is largely unexplored. METHODS: Outcomes of 3391 consecutive BITA patients were reviewed retrospectively. Patients with DSWI after surgery (n = 142, 4.2%) were compared with those having no sternal complications (n = 3177). Predictors of DSWI and of mortality during the follow-up period were found with negative-binomial and Cox proportional-hazards regression, respectively. One-to-one propensity score-matched analysis, which considered simultaneously baseline patient characteristics, operative data, and postoperative complications was performed. The resulting matched pairs were compared for non-parametric estimates of late survival. The same comparison was performed in matched pairs having no major complications (except DSWI) early after surgery. RESULTS: In-hospital mortality was higher in DSWI cohort than in patients having no sternal complications (5.6% vs. 1.8%, p = 0.0035). Almost all of postoperative complications were more frequent in DSWI patients. Female sex, obesity, chronic lung disease, renal impairment, extracardiac arteriopathy, congestive heart failure, and urgent/emergency priority were predictors of DSWI common to two DSWI risk models that were developed. DSWI was independent predictor of reduced late survival (multiple covariates-adjusted hazard ratio [HR], 1.91, p < 0.0001). The propensity matching resulted in 135 pairs with same in-hospital mortality (5.2%). Estimates of freedom from all-cause death were lower in DSWI cohort (HR, 1.92, p < 0.0001), even when only pairs (n = 59) having no major postoperative complications (except DSWI) were considered (HR, 1.84, p = 0.026). CONCLUSIONS: DSWI after BITA use seems to reduce late survival even after adjusting for baseline patient characteristics and concomitant postoperative complications.