Could effect of smoking guide us to a new treatment option for atrial fibrillation?

We found the article by Al-Sarraf et al. interesting but provocative [1]. Smoking is always supposed to do harm and cause all sorts of cardiovascular diseases leading to high morbidity and mortality. The potential risks of active smoking are pulmonary complications, prolonged postoperative ventilation and early bypass occlusion due to corrosive and harmful effects of smoke. But its role in decreasing atrial fibrillation in patients undergoing coronary artery bypass graft (CABG) is of real interest [1]. In general, active smoking patients should be advised to terminate smoking at least four weeks before surgery to decrease the volume of airway secretions and pulmonary complications and to improve mucociliary transport [2].

Atrial fibrillation in patients after CABG has several etiologies like: multiple wavelet re-entry in the atria, rapid firing of an atrial focus, and less likely, atrial ischemia. Preoperative clinical predictors of atrial fibrillation after cardiac surgery include increased age, history of hypertension, male gender, previous history of atrial fibrillation or congestive heart failure, peripheral and/or cerebral vascular disease, and severity of coronary artery disease [3]. Although, the authors made a logistic regression analysis and showed that current smokers had a 30% risk reduction compared to non-smokers after accounting for potential confounders, they have not mentioned the status of the thyroid hormone in their patients. Cerillo et al. [4] have shown that low free T3 hormone could potentially predispose to atrial arrhythmias in CABG patients. Klemperer et al. [5] have proposed administration of exogenous T3 to reduce the incidence of postoperative AF in CABG patients. Al-Sarraf et al. [1] have already cautioned not to take their result as an encouragement for smoking. However, this study raises the possibility to think about a well structured randomized control study with nicotine therapy in non-smoker patients undergoing CABG, taking into consideration that nicotine is the main substance in smoking, which probably has protective effects. Ironically, as smoking cannot be advised, the authors might in the future think of proposing a treatment with nicotine patches or tablets to non-smoker patients before CABG to prevent postoperative atrial fibrillation.

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