Arbucci, R O S I N A

Abstract Background Ischemic mitral regurgitation (IMR) is a common complication of coronary artery disease (CAD), often occurring after myocardial infarction (MI). Even when moderate in severity, IMR is associated with adverse outcomes, including a twofold increase in mortality rates. Aim To assess the functional correlates of resting IMR during stress echocardiography (SE) in patients with CAD. Methods This prospective multicenter study included 192 patients with CAD (143 males; mean age 65 ± 10 years) from eight cardiology institutions. Exclusion criteria included a history of coronary artery bypass surgery, more than moderate IMR, and other significant valvular diseases. Patients were divided into two groups based on semiquantitative- quantitative assessment at rest based on EACVI-ASE criteria: Group 1: Patients with moderate IMR, Group 2: Patients without IMR or with trivial IMR. All patients underwent stress echocardiography (SE) using the ABCE protocol. Patients underwent exercise tests, if execise echocardiography was not possible, dobutamine stress tests were performed. At rest and peak SE, we assessed: Left atrial volume index (LAVi), Left ventricular end-diastolic (LV EDV) and end-systolic volumes (LV ESV), ejection fraction (EF), wall motion score index (WMSI), global longitudinal strain (GLS), B-lines (4-site simplified scan), tricuspid annular plane systolic excursion (TAPSE), systolic pulmonary artery pressure (SPAP), LV contractile reserve (LVCR) and heart rate reserve (HRR). Results Despite similar EF at rest, Group 1 patients showed more pronounced functional impairment at rest, which increased during stress. Stress-induced functional worsening affected indices of MR (more frequently becoming severe), ischemic burden (WMSI), diastolic function (LAVI and LVEDV dilation), LV systolic function (LVCR), pulmonary congestion (B-lines), cardiac sympathetic reserve (reduced HRR) and right ventricular/pulmonary artery coupling (reduced TAPSE/SPAP): table 1. Conclusion Compared to CAD patients with absent-to-trivial resting IMR, patients with moderate IMR at rest show a constellation of functional vulnerabilities during SE involving more frequent exercise-induced worsening of MR, blunted LV diastolic and systolic reserve, more pulmonary congestion, impaired cardiac autonomic reserve, and worse right ventricular-pulmonary artery coupling. The individual patient's functional response heterogeneity can be identified with comprehensive exercise SE, possibly a roadmap to personalized and targeted therapeutic interventions.