Steroid use for recovery of advanced atrioventricular block immediately after valvular surgery (survival): a randomized clinical trial

Funding Acknowledgements Type of funding sources: None. Background Limited inconsistent evidence support use of steroids in recovery of atrioventricular block (AVB) after trans-catheter aortic valve implantation. However, there is no study to examine the efficacy of steroids in recovery of high-grade AVB following valvular surgery. Purpose To assess the effect of high-dose dexamethasone on recovery of advanced AVB following valvular heart surgery. Methods In this randomized controlled trial, patients with advanced postoperative AVB (either Mobitz type II or third degree) were randomly assigned to receive either dexamethasone (0.4 mg /kg, maximum 30 mg /day in three divided doses) intravenously for three days or conservative care only. Primary endpoint was recovery rate in day five since randomization. Secondary endpoints were recovery rate in day 7 and day 10, cumulative AVB time, PPM implantation rate, length of stay in critical care units, and post-operative major adverse events (MAE) during one month. We defined MAE as composite of all-cause mortality, all-type infections, major bleeding, prolonged sternal dehiscence, new stroke, postoperative MI, complicated uncontrolled hyperglycemia and readmission for decompensated heart failure. Results We enrolled 139 subjects (48.9% male) with mean age of 59.9 years who were randomly allocated to intervention group (n= 69) and control group (n= 70). Dexamethasone led to higher recovery rates at day 5 (82.6% vs. 62.9%, P= 0.009) and day 7 (88.4% vs. 61.4%, P< 0.0001) respectively. Random 24-hours ECG Holter monitoring of patients at day 5 revealed the same results and confirmed the superiority of dexamethasone for recovery of AVB (80.5% vs 61.2%, respectively, P = 0.024). Although this benefit ceased at day 10 (83.05 vs 78.6 %, P = 0.547), Generalized Estimating Equation analysis for recovery over 10 days favored intervention (odds ratio: 2.56, 95% CI: 1.27- 5.15, P = 0.008). Median cumulative AVB time was shorter in dexamethasone group compared to control group (41 hours vs 64 hours, P = 0.044). PPM implantation rates were similar between the dexamethasone and control groups (15.9% vs 17.1 %, respectively, P = 0.849). Median length of stay in ICU (10 days vs 12 days, P= 0.03) and MAE (17.4 % vs 25.7%, P = 0.133) tended to be lower with dexamethasone. Conclusion Our findings suggest that dexamethasone may serve as a safe and effective medication to improve recovery of advanced AVB after valvular surgery. Further studies are needed to confirm these findings, particularly regarding subsequent PPM implantation rate.