CHANGES IN LEFT ATRIAL VOLUME DURING ECHOSTRESS IN PATIENTS UNDERGOING MITRAL VALVE PLASTIC CARDIAC SURGERY

Abstract

Abstract Mitral Regurgitation (MR) is characterized by a high morbidity and mortality that often finds a solution only in the reparative surgical treatment, in particular in presence of myxomatous degeneration that cause the prolapse of one or both leaflets. This results in an increase in diastolic pressure that leads to a progressive dilation of the left atrium. The increase in Left Atrium Volume Index (LAVI) during stress test represents a negative prognostic factor in the clinical evolution of many pathologies, such as ischemic heart disease, hypertrophic cardiomyopathy, heart failure. An increase in peak/rest LAVI >6.8 ml/m2 correlates with a higher incidence of heart failure decompensation, reduced left ventricular contractile reserve (LVCR), pulmonary congestion. We evaluate the effect of MR reparative surgery on the changes of LAVI during stress–echo. We enrolled 19 patients, 11 females and 8 males, affected by MR candidate to cardiac surgery. We performed a physical stress–echo test by using the ABCDE protocol suggested by the Italian Society of Echocardiography and Cardiovascular Imaging (SIECVI), before and after 12 weeks from surgery. During each test, the changes in LAVI (ΔLAVI) expressed as peak/rest difference in ml/m2 was measured. In addition, the prognostic score deriving from the sum of the ABCDE criteria was calculated, such as the LVCR (C parameter of the score) that represents a parameter of the force deriving from the hemodynamic changes during the test. In all patients we observed a significant reduction in ΔLAVI (8.4+0.5 mL/m2 vs 9.7+0.7 mL/m2; p<0.0001). In addition, there was a significant reduction in the ABCDE prognostic score (from 4.19+0.43 to 3.48+0.37; p=0.002), secondary to the increase in the LVCR observed approximately 3 months after surgery (from 1.77 mmHg/ml to 2.44 mmHg/ml, p<0.0001), as well as a significant reduction in pulmonary congestion during stress (B parameter). There were no significant changes in ejection fraction, wall motion score index–WMSI (A parameter), coronary reserve (D parameter) and heart rate reserve (E parameter). These data demonstrate for the first time that mitral valve plastic surgery is able to reduce the ΔLAVI during stress echocardiography in patients with severe MR. The surgical procedure also resulted in both an improvement in the LVCR and a reduction in the degree of pulmonary congestion, that ultimately led to an improvement in the ABCDE prognostic score.