Background— Atrial fibrillation (AF) after coronary artery bypass graft surgery is a difficult problem and a continuing source of morbidity and mortality. However, the prognostic implications of postoperative AF are still in dispute. Our aim was to ascertain the impact of AF after coronary artery bypass graft on postoperative survival and to assess its prognostic role in cause-specific mortality. Methods and Results— We conducted a prospective observational study of 1832 patients undergoing isolated coronary artery bypass graft between January 2000 and December 2005 at 2 cardiac surgery centers in northern Italy. Patients affected by postoperative AF were identified and followed up until death or study end (April 30, 2007). A total of 570 patients (31%) developed AF after coronary surgery. Patients affected by postoperative AF experienced a longer hospital stay (7 days [25th to 75th percentile, 7 to 10 days] versus 7 days [25th to 75th percentile, 6 to 8 days]; P <0.001). Hospital mortality also was higher in AF patients (3.3% versus 0.5%; P <0.001). On discharge, 1806 patients were alive; 143 were lost to follow-up. The remaining 1663 were followed up for a median of 51 months (25th to 75th percentile, 41 to 63 months); 126 of them died after a median of 14 months (25th to 75th percentile, 5 to 32 months). Long-term mortality rates were significantly higher for patients with postoperative AF (2.99 per 100 person-years; 95% confidence interval, 2.33 to 3.84; 61 deaths) compared with those without the arrhythmia (1.34 per 100 person-years; 95% confidence interval, 1.05 to 1.71; 65 deaths), with an adjusted hazard ratio of 2.13 ( P <0.001) and 2.56 ( P =0.001) when also accounting for the prescription of warfarin at discharge. With Cox regression, patients with AF were shown to be at higher risk of dying from embolism (adjusted hazard ratio, 4.33; 95% confidence interval, 1.78 to 10.52) but not from other causes. Conclusions— Postoperative AF affects early and late mortality after isolated coronary artery bypass graft surgery. Patients affected by AF are at higher risk of fatal embolic events. Careful postoperative surveillance with a specific antiarrhythmic and antithrombotic prophylaxis, aimed at reducing AF and its complications, is recommended.

Background—In an apparent paradox morbidity and mortality are lower in obese patients undergoing cardiac surgery, although the nature of this association is unclear. We sought to determine whether the obesity paradox observed in cardiac surgery is attributable to reverse epidemiology, bias, or confounding. Methods—Data from the National Adult Cardiac Surgery registry for all cardiac surgical procedures performed between April 2002 and March 2013 were extracted. A parallel systematic review and meta-analysis (MEDLINE, Embase, SCOPUS, Cochrane Library) through June 2015 was also accomplished. Exposure of interest was body mass index (BMI) categorised into 6 groups according to the World Health Organisation classification. Results—A total of 401 227 adult patients in the cohort study, and 557 720 patients in the systematic review were included. A "U-shape" association between mortality and BMI classes was observed in both studies, with lower mortality in overweight (adjusted odds ratio [OR], 0.79; 95% confidence interval [CI], 0.76-0.83) and obese class I and II (OR, 0.81; 95%CI, 0.76-0.86 and OR, 0.83; 95%CI, 0.74-0.94) patients relative to normal weight patients and increased mortality in underweight individuals (OR, 1.51; 95%CI 1.41-1.62). In the cohort study, a "U-shaped" relationship was observed for stroke and low cardiac output syndrome, but not for renal replacement therapy or deep sternal wound infection. Counter to the reverse epidemiology hypotheses the protective effects of obesity were less in patients with severe chronic renal, lung or cardiac disease and greater in older patients, and in those with complications of obesity including the metabolic syndrome and atherosclerosis. Adjustments for important confounders did not alter our results. Conclusions—Obesity is associated with lower risks after cardiac surgery, with consistent effects noted in multiple analyses attempting to address residual confounding and reverse causation.

Background: Atrial fibrillation ( AF ) remains the most common complication after cardiac surgery. The present study aim was to derive an effective bedside tool to predict postoperative AF and its related complications. Methods and Results: Data of 17 262 patients undergoing adult cardiac surgery were retrieved at 3 European university hospitals. A risk score for postoperative AF ( POAF score) was derived and validated. In the overall series, 4561 patients (26.4%) developed postoperative AF . In the derivation cohort age, chronic obstructive pulmonary disease, emergency operation, preoperative intra‐aortic balloon pump, left ventricular ejection fraction <30%, estimated glomerular filtration rate <15 mL/min per m ² or dialysis, and any heart valve surgery were independent AF predictors. POAF score was calculated by summing weighting points for each independent AF predictor. According to the prediction model, the incidences of postoperative AF in the derivation cohort were 0, 11.1%; 1, 20.1%; 2, 28.7%; and ≥3, 40.9% ( P <0.001), and in the validation cohort they were 0, 13.2%; 1, 19.5%; 2, 29.9%; and ≥3, 42.5% ( P <0.001). Patients with a POAF score ≥3, compared with those without arrhythmia, revealed an increased risk of hospital mortality (5.5% versus 3.2%, P =0.001), death after the first postoperative day (5.1% versus 2.6%, P <0.001), cerebrovascular accident (7.8% versus 4.2%, P <0.001), acute kidney injury (15.1% versus 7.1%, P <0.001), renal replacement therapy (3.8% versus 1.4%, P <0.001), and length of hospital stay (mean 13.2 versus 10.2 days, P <0.001). Conclusions: The POAF score is a simple, accurate bedside tool to predict postoperative AF and its related or accompanying complications.

Atrial fibrillation (AF) after thoracic surgery is a continuing source of morbidity and mortality. The effect of postoperative AF on long-term survival however has not been studied. Our aim was to evaluate the impact of AF on early outcome and on survival > 5 years after pulmonary lobectomy for lung cancer.