IMPACT OF PREOPERATIVE METOPROLOL ON THE OCCURRENCE OF NEW-ONSET ATRIAL FIBRILLATION AFTER CORONARY ARTERY BYPASS GRAFTING

Abstract

Salla Surya Prakasarao 1 , Sweta Ramani 2 , Nikitha Manem3

BACKGROUND Postoperative Atrial fibrillation (POAF) is the most frequent arrhythmia observed after Coronary artery bypass grafting (CABG). Worldwide incidence is documented to be 20-30% in patients undergoing isolated Coronary artery bypass grafting (CABG). There is no published data for Indian population so far. Hence, the objective of our study is to analyse the occurrence of newonset POAF in our Indian population and to assess whether the preoperative beta-blocker therapy has any role in its prevention. MATERIAL AND METHODS This is a retrospective and prospective observational study of coronary artery disease patients in Andhra Medical College, Visakhapatnam, who underwent coronary artery bypass grafting at various institutions between August 2013 and August 2014. The patients with documented AF during the preoperative period and patients undergoing associated cardiac procedures have been excluded from the study. Data has been collected from the patients’ medical records and the relative clinical variables were analysed. Chi-square test used for statistical analysis. RESULTS 227 patients with coronary artery disease (followed up at our centre) were found to have undergone CABG during the study period. Among the 227 patients, 191 (84.14%) were males and 36 (15.85%) were females. The mean age of patients developing AF was 61.9±8.7 and for patients in sinus rhythm was 58.7±7.9 years (range: 37-80 years). 159 patients received preoperative Metoprolol and 68 patients were free from Metoprolol usage. The overall incidence of AF was 6.16%. 3.1% of patients with Metoprolol were noted to have AF while 13.23% of patients with no Metoprolol coverage developed new-onset AF (p<0.05). 14.28% of patients developing AF were with LV function <40%. The mean duration of ICU stay for patients who had POAF was 73.74±39.33 hours and 34.47±19.39 hours for patients in sinus rhythm. CONCLUSION The incidence of Postoperative Atrial fibrillation in Indian patients is less than the western population. Advanced age and Left ventricular dysfunction increases the risk. The technique of the surgery is not found to be affecting. Postoperative AF remains common with an incidence of 6.14%. The study has shown that preoperative therapy with Metoprolol continuing through the postoperative period significantly reduces the incidence of new-onset postoperative Atrial fibrillation in coronary artery disease patients undergoing coronary bypass grafting.

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