The risk of arrhythmias following coronary artery bypass surgery: do smokers have a paradox effect?
Smoking is reported to increase the risk of arrhythmias. However, there are limited data on its effects on arrhythmias following coronary artery bypass graft (CABG). This is a retrospective review of a prospective database of all CABG patients over an eight-year period. Our cohort (n=2813) was subdivided into: current (n=1169), former (n=837), and non-smokers (n=807). Predictors of arrhythmias following CABG in relation to smoking status were analysed. Atrial arrhythmias occurred in 942 patients (33%). Ventricular arrhythmias occurred in 48 patients (2%) and high-grade atrioventricular block occurred in five patients (0.2%). Arrhythmias were lower in current smokers than former and non-smokers (29% vs. 40% vs. 39%, respectively P<0.001). Logistic regression analysis showed 30% arrhythmia risk reduction in smokers compared to non-smokers [odds ratio (OR) 0.7, 95% confidence intervals (CI) 0.5-0.8] and this effect persisted after accounting for potential confounders while former smokers had the same risk as non-smokers (OR 1.04, CI 0.9-1.3). There were no significant differences in mortality. Smokers are less prone to develop arrhythmias following CABG. This paradox effect is lost in former smokers. This effect is possibly due to a lower state of hyper adrenergic stimulation observed in smokers than non-smokers following the stress of surgery.
Al-Sarraf
Nael
N
Department of Cardiothoracic Surgery, St. James's Hospital, Dublin 8, Ireland. trinityq8@hotmail.com
Thalib
Lukman
L
Hughes
Anne
A
Houlihan
Maighread
M
Tolan
Michael
M
Young
Vincent
V
McGovern
Eillish
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D019992:Databases as Topic; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome