Perioperative Amiodarone to Prevent Atrial fibrillation after Septal Myectomy in obstrUctive hypeRtroPHic cardiomyopathy

Abstract

Aims Amiodarone reduces the incidence of atrial fibrillation (AF) following coronary artery bypass surgery; however, the benefit of perioperative amiodarone in patients undergoing septal myectomy (SM) for obstructive hypertrophic cardiomyopathy (oHCM) has not been studied. We hypothesized that prophylactic amiodarone would reduce the incidence of postoperative AF (POAF) following SM for oHCM. Methods and Results A single‐centre, pre‐post intervention open‐label study of oral amiodarone (200 mg twice daily starting 7 days preoperatively and 200 mg once daily continuing for 30 days postoperatively) in patients without prior AF undergoing SM for oHCM from 2014 to 2018. The primary outcome was incident AF within 30 days. Secondary outcomes were unplanned readmission, AF treatment, total and intensive care unit (ICU) length of stay (LOS), and pacemaker implantation for high‐grade atrioventricular (AV) block. 61 patients met inclusion criteria with 34 (55.8%) in the pre‐intervention (control) group and 27 (44.2%) in the post‐intervention (amiodarone) group. The incidence of POAF was 11.0% in the amiodarone group compared with 38.2% in the control group (P = 0.017). After adjusting for age, amiodarone was associated with less POAF [adjusted odds ratio (aOR) 0.21; 95% confidence interval (CI) 0.05, 0.76; P = 0.016]. ICU (2 days [IQR 1, 4] vs. 3 days [IQR 2, 4]; P = 0.165) and total (6 days [IQR 5, 6] vs. 6 days [IQR 5, 7]; P = 0.165) LOS were similar, as was the rate of pacemaker implantation (7.4% vs. 8.3%, P > 0.999). There were no adverse events associated with amiodarone. Conclusions Perioperative oral amiodarone is safe and was associated with lower incidence of POAF following SM for oHCM.

Transapical beating-heart septal myectomy for hypertrophic cardiomyopathy with latent obstruction

“…In addition, 1 resumed normal conduction without pacemaker dependence 2 months after surgery. In our cohort, the incidence of new-onset atrial fibrillation occurred in 3 (2.5%) patients, which seemed lower than 11–13% of prior studies [ 24 , 25 ]. This favourable impact on atrial fibrillation was likely explained by the promising clinical outcomes of TA-BSM, including the reduction in maximum LVOT gradient, MR severity and left atrial size [ 26 , 27 ].…”

“…The left atrial chamber size was larger in patients with resting obstruction ( P = 0.027). Patients with latent obstruction had a lower ratio of early ventricular filling to early diastolic mitral annular velocity (13 [12, 18] vs 18 [ 13 , 24 ], P = 0.004). The proportion of MR ≥grade 2+ was significantly lower in patients with latent obstruction compared with those with resting obstruction (63.6% vs 90.8%; P < 0.001).…”

Evolving Contemporary Management of Atrial Fibrillation in Hypertrophic Cardiomyopathy

“…AF episodes isolated to the first 2 to 3 months after myectomy occur in ≈30% of patients. 100–102 These postoperative AF episodes do not appear to be associated with long-term risk for embolic stroke, suggesting that routine long-term anticoagulation is not necessary after the initial postoperative period for these patients. 100 However, postoperative AF does predict future AF.…”

“…100 However, postoperative AF does predict future AF. 100 Some centers have administered amiodarone prophylactically after myectomy to prevent these episodes, a strategy that decreases postoperative AF risk, but does not reduce the length of hospitalization 101…”