Effects of diltiazem prophylaxis on the incidence and clinical outcome of atrial arrhythmias after thoracic surgery

Objectives: We sought to determine whether early prophylaxis with an L-type calcium channel blocker reduces the incidence and morbidity associated with atrial fibrillation/flutter and supraventricular tachyarrhythmia after major thoracic operations. Methods: In this randomized, double-blind, placebo-controlled study, 330 patients were given either intravenous diltiazem (n = 167) or placebo (n = 163) immediately after lobectomy (greater than or equal to 60 years) or pneumonectomy (greater than or equal to 18 years) and orally thereafter for 14 days. The primary end point with respect to efficacy was a sustained (greater than or equal to 15 minutes) or clinically significant atrial arrhythmia during treatment. Results: Postoperative atrial arrhythmias (atrial fibrillation/flutter = 60; supraventricular tachyarrhythmias = 5) occurred in 25 (15%) of the 167 patients in the diltiazem group and 40 (25%) of the 163 patients in the placebo group (P =.03). When compared with placebo, diltiazem nearly halved the incidence of clinically significant arrhythmias (17/167 [10%] vs 31/163 [19%], P =.02), The 2 groups did not differ in the incidence of other major postoperative complications or overall duration or costs of hospitalization. No serious adverse effects caused by diltiazem were seen. Conclusions: After major thoracic operations, prophylactic diltiazem reduced the incidence of clinically significant atrial arrhythmias in patients considered at high risk for this complication.