Functional Evaluation of the Myocardial Ischemia After Coronary Artery Bypass Surgery Using Coronary Flow Velocity Reserve in Left Ventricular Hypertrophy.

Patients with left ventricular hypertrophy (LVH) have reportedly higher than normal mortality and incidences of cardiovascular events. Coronary microvascular pathophysiology also appears to differ from other populations. Such coronary microcirculation dysfunctions are considered strong causes of cardiac events. We compare the functional improvement of myocardial ischemia between LVH patients and other patients after successful coronary artery bypass surgery (CABG) using coronary flow velocity reserve (CFVR) by transthoracic echo cardiography. Patients who underwent isolated coronary artery bypass surgery, including left anterior descending artery (LAD) revascularization via "in situ" internal thoracic artery (ITA) between June 2008 and July 2017 (n = 155), were retrospectively reviewed. ITA grafts were patent in postoperative graft evaluation in all patients. CFVR was evaluated pre- and postoperatively, and data were compared between patients with severe LVH group and those without (non-LVH group). Preoperative mean CFVR was 1.77 ± 0.75 in LVH group and 1.91 ± 0.63 in non-LVH group (P = 0.188). After the operation, ITA to LAD graft patency was confirmed in all patients. Postoperative CFVR was 2.23 ± 0.70 in LVH group and 2.85 ± 0.71 in non-LVH group, respectively (P = 0.002). Significant difference was observed between the 2 groups. CFVR values improved after ITA to LAD bypass grafting in both LVH and non-LVH groups, but postoperative CFVR was significantly lower in patients with severe LVH than in patients without. Myocardial ischemia may exist in patients with LVH, despite patent graft, due to microvascular dysfunction. Comprehensive treatment, including long-term oral medication to improve microvascular dysfunction, is necessary for patients with LVH.