on September 29, 2008
Published online before print September 29, 2008, doi: 10.1161/CIRCULATIONAHA.108.777789
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Submitted on March 6, 2008
From the Department of Surgical Sciences, Cardiac Surgery Unit, Varese University Hospital, University of Insubria, Varese, Italy (G.M., S.F., P. Borsani, C.C., A.S.); Service of Biometry and Clinical Epidemiology, Scientific Direction, IRCCS Fondazione Policlinico San Matteo, Pavia, Italy (C.K.); Department of Cardiovascular Surgery, University of Milan, Centro Cardiologico Monzino IRCCS, Milan, Italy (M.Z., P. Biglioli); and Department of Cardiac Surgery, 1st Chair of Cardiology and Cardiac Surgery, Medical University of Lodz, Lodz, Poland (M.B.). * To whom correspondence should be addressed. E-mail: giovannimariscalco{at}yahoo.it.
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.
Accepted on July 29, 2008
Atrial Fibrillation After Isolated Coronary Surgery Affects Late Survival
Giovanni Mariscalco MD*,
Key words: atrial fibrillation • cardiac surgical procedures • embolism • mortality
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