High Thoracic Epidural Decreases Perioperative Myocardial Ischemia and Improves Left Ventricle Function in Aortic Valve Replacement Alone or in Addition to CABG Surgery Even with Increased Left Ventricle Mass Index

INTRODUCTION: High thoracic epidural (HTE) may reduce perioperative tachyarrhythmias, respiratory complications and myocardial ischemia (MI) and it may increase coronary perfusion and myocardial oxygen balance through sympatholysis and pain control. The aim of this study is to investigate the benefit of HTE in patients undergoing aortic valve replacement (AVR) alone or in addition to coronary artery bypass graft (CABG). METHODS: This prospective randomized controlled study was conducted on 80 patients (40 with increased left ventricular mass index (LVMI) and 40 with normal LVMI) who were equally randomised (n = 40) to receive either GA with HTE (HTE group) or GA alone (GA group). Heart rate (HR), mean arterial blood pressure (MAP) and the incidence of ischemic ECG changes were recorded. LV functions (preoperative and postoperative by transthoracic echocardiography and intraoperative by transoesophageal echocardiography) were measured preoperative, intraoperative and till 48 H postoperative. RESULTS: There was no significant difference in the baseline values of all measurements. HR and MAP were lower, and LV functions were improved in HTE group intraoperatively and postoperatively. Ischemic ECG changes were significantly lower in HTE group; with 42.9% intraoperative risk reduction (95% CI: 0.195-0.943) and 46.6% postoperative risk reduction (95% CI 0.227-0.952) as compared to GA group. The risk of ischemia was significantly higher in patients with increased LVMI in GA group (2.25 times compared to normal LVMI patients with 95% CI: 1.195-4.236), but it wasn't increased in HTE group. LV functions were significantly improved from the induction to 48 H postoperative in HTE group as compared to GA group. CONCLUSION: HTE reduced the incidence of MI and improved the LV function, even with increased LVM, in patients undergoing AVR alone or in addition to CABG.