Differential myocardial strain in the early postoperative period in patients receiving arterial vs venous bypass grafts: A hypothesis-generating study.

Abstract

Revascularization via coronary artery bypass grafting (CABG) remains a common therapy for coronary artery disease. CABG-based revascularization is most commonly performed via either single arterial graft (SAG) or multiple arterial grafting (MAG) strategies. Echo-derived global and regional longitudinal strain was used to test where SAG or MAG results in immediate differences in left ventricular (LV) function after CABG. Pre- and postprocedural intraoperative transesophageal echos were prospectively collected. Two-dimensional LV images were analyzed for global and regional longitudinal strain (GLS), LV ejection fraction, end-diastolic volume, end-systolic volume, and stroke volume (SV). Twenty patients underwent open, on-pump CABG (63.9 ± 10 years old, 85% male; 10 with SAG and 10 with MAG. Preprocedural GLS significantly differed between patients with SAG and MAG, with patients with MAG having greater GLS (mean [standard deviation, SD], 20.41 [5.54]) than patients with SAG (16.28 [3.48]). After CABG, in patients with MAG, LV strain decreased both globally (-1.13 [3.15]) and regionally in the anterior-lateral (-1.22 [3.84]) and inferior-lateral regions (-1.32 [5.69]), along with LVEF. In patients with SAG, LV strain increased after CABG globally (1.34 [2.73]) and regionally in the anterior-lateral (1.20 [6.49]) and inferior-lateral regions (0.39 [7.26]), as did LVEF and SV. Postprocedure, more patients with MAG were given vasopressor (100% vs 60%) and inotrope infusions (70% vs 40%) than patients with SAG. After CABG, LV function quantified through GLS changes both globally and regionally increased after SAG and decreased after MAG. This finding may have important clinical implications in terms of optimizing intraoperative management for patients with CABG and have the potential to guide the improvement of clinical outcomes.