Hyperglycemia predicts mortality after CABG: postoperative hyperglycemia predicts dramatic increases in mortality after coronary artery bypass graft surgery.

OBJECTIVE: Risk of morbidity and mortality after coronary artery bypass graft surgery (CABG) is higher in patients with clinical diabetes mellitus (DM). We evaluated whether outcomes are affected by postoperative hyperglycemia in CABG patients independent of preoperative DM diagnosis. RESEARCH DESIGN AND METHODS: A total of 2297 consecutive CABG patients were studied. The first glucose value after surgery completion (mean 15 min) was tested as a predictor of outcome. Primary outcome variables were prolonged ventilation (>24 h), deep sternal wound infection, renal failure, permanent stroke, any reoperation, length of stay (>14 days) and mortality. All outcomes except for prolonged ventilation and length of stay were tracked out to 30 days postoperatively. Patients were stratified by glycemic control: Low (glucose <80), normal (referent, glucose 80-110), high (glucose 111-200) and very high (glucose >200 mg/dl). Multivariable logistic regression was used to determine the independent predictive value of glycemic groups, adjusted for outcome specific risk scores from the Society of Thoracic Surgeons model. RESULTS: Patient distribution among groups low through very high were 44 (1.9%), 476 (20.7%), 1425 (62.0%) and 352 (15.3%). Greater complication rates were noted in the very high group when compared with the referent group: prolonged ventilation (adjusted odds ratio (OR)=2.66, P<.001), length of stay >14 days (adjusted OR=2.06, P=.004) and mortality (adjusted OR=7.71, P<.001). CONCLUSION: Patients with blood glucose values >200 mg/dl immediately after CABG had an increased risk of complications, including mortality, independent of a clinical diagnosis of DM. This study documents the high risk associated with early postoperative hyperglycemia in this group, suggesting the need for prospective trials of glycemic control.

Comparison of standard Maze III and radiofrequency Maze operations for treatment of atrial fibrillation.

OBJECTIVE: This study compares clinical results of the standard Maze III operation, a highly effective treatment for atrial fibrillation, to less complex variations of the Maze III operation utilizing unipolar and bipolar radiofrequency ablation and pulmonary vein isolation. METHODS: Records were reviewed of 377 patients who had operations for treatment of atrial fibrillation at a single institution over a 10-year period. Standard Maze III was performed in 220 patients, unipolar radiofrequency Maze III in 60, bipolar radiofrequency Maze III in 65, and radiofrequency pulmonary vein isolation in 32. Electrocardiograms were obtained at discharge and 3-, 6-, and 12-month intervals. Chi-square test, logistic regression, and Bayesian theory analyses were performed to determine significant associations between operative procedures and outcomes. RESULTS: Mean age was 65.1 years (range 22-87). There were 13 hospital deaths (3.4%) and 16 deaths during follow-up. Most patients (90.2%, 340/377) had concomitant operations. Electrocardiogram analysis was available in 344 patients at 3 months and 313 patients at 6 months. Freedom from atrial fibrillation at 6 months was superior after standard Maze III compared with radiofrequency modifications. Subanalysis according to surgeon experience demonstrated good results regardless of operative experience. CONCLUSIONS: This single-institution experience suggests that the standard Maze III operation is superior to radiofrequency operations for treatment of atrial fibrillation. Radiofrequency modifications of the Maze III operation are also effective treatments for atrial fibrillation and can achieve good results regardless of surgeon experience.