Association between Left Ventricular Longitudinal Strain (GLS) and Prognosis of the Patients Undergoing Heart Valve Surgery with Preserved Left Ventricular Ejection Fraction

Abstract

Purpose: Global longitudinal strain (GLS) seems accurate for detecting subclinical myocardial dysfunction. This study aimed to determine the association between GLS and postoperative intensity of inotropic support in the patients undergoing heart valve surgery with preserved left ventricular ejection fraction. Methods: 74 patients with preserved left ventricular ejection fraction who underwent valve surgery during the period between March 2021 and June 2022 were included in this prospective observational study. Transthoracic echocardiography including strain analysis with speckle tracking was performed before surgery. Patients were stratified according to the left ventricle (LV) GLS: LV-GLS ≥–16% (Impaired GLS group) and LV-GLS <–16% (Normal GLS group). The primary endpoint was postoperative vasoactive inotropic score. A high vasoactive inotropic score (VIS) was defined as a maximum VIS of ≥15 within 24 hours postoperatively. Postoperative adverse events, baseline clinical and echocardiographic data were also recorded. We invested the ability of preoperative GLS in predicting adverse postoperative outcomes, such as prolonged mechanical ventilation and the need for pharmacologic hemodynamic support after cardiac surgery. Results: Seventy-four patients were included and analyzed in this study, including thirty-three in impaired GLS group and forty-one in normal GLS group. In-hospital mortality was 1.27% (1/74). Patients in impaired GLS group were more likely to have prolonged mechanical ventilation (p = 0.041). Multivariable logistic regression analysis revealed that the apical four-chamber view of the left ventricle (A4C)-GLS was significantly associated with high VIS (OR 1.373, p = 0.007). A4C-GLS had a sensitivity of 62.5% and a specificity of 89.66% for predicting high VIS (area under the curve, 0.78). The relationships between GLS and other secondary outcome measures were not statistically significant. The optimal cutoff of A4C-GLS for postoperative high vasoactive inotropic score was –10.85%. Conclusion: Preoperative LV dysfunction is an independent risk factor for postoperative high VIS. A4C-GLS may be a reliable tool in predicting high VIS after cardiac surgery. Those patients with impaired contractility were at high risk for elevated inotropic support and prolonged mechanical ventilation after cardiac surgery. These findings suggest an important role for echocardiographic GLS in perioperative assessment of cardiac function in the patients undergoing cardiac surgery.