Verlauf und prognostische Bedeutung der nicht korrigierten Mitralklappeninsuffizienz im mittelfristigen und langzeitigen follow-up

Clinical background Implantation of LVAD (Left Ventricular Assist Device) with continuous flow significantly reduces the severity of concomitant MI in patients with end-stage heart failure. By restoring the left ventricular geometry under volume and pressure relief, LVAD therapy enables better closure of the mitral valve leaflets and, in the vast majority of cases, a long-term reduction in MI. There are different points of view on the need for additional mitral valve surgery during LVAD implantation. Patients and methods We report on 165 patients operated on in the period, from the beginning of 2012 to the end of 2019, in whom we implanted an LVAD system as a destination therapy without concomitant mitral valve surgery. Patients are divided into two groups according to the severity of MI existing at the time of LVAD implantation: Group MI 0/I° – patients who have no or only mild MI vs. Group MI II/III° patients who have medium/high grade MI. From the group of still living LVAD patients, we were able to recruit a total of 55 patients in compliance with the inclusion and exclusion criteria and prospectively examine them according to study protocol using dynamic stress echocardiography and spiroergometry within the same patient visits. As objectives of this research we have set the following: 1. Checking the effectiveness of LVAD therapy to minimize an uncorrected MI ≥ II° during LVAD implantation in the long term at rest, and also under physical stress. 2. Identify an etiological subset of patients who have little benefit from solitary LVAD implantation and who are expected to achieve further clinical improvement through additional mitral valve surgery during LVAD implantation. Results This study showed that LVAD implantation as a solitary therapy for the treatment of heart failure can stop a progressive course and minimize medium/high grade MI in the long term or prevent the development of such. Both in the overall analysis with reference only to the severity of MI at the time of LVAD implantation, and in the subgroup analysis taking into account the etiology of cardiomyopathy (CMP), this study showed no significant difference in medium-term and long-term follow-up in terms of survival rate, potential for RV and LV reverse remodeling, progression of chronic renal failure, reuptake rate, the NT-pro-BNP course, the stroke volume increase under load and the maximum oxygen uptake. Under physical exertion, LVAD therapy proves to be just as effective, with exercise-induced (latent) moderate to high-grade MI occurring in only 12% of patients. In general, apart from the MI severity, the exercise capacity of HI patients remains very limited even after LVAD implantation. Limited in terms of validity, the results of the present work can be interpreted as suggesting a negative effect of uncorrected moderate to high-grade MI in patients with non-ischemic CMP and TAPSE ≤ 14mm prior to LVAD implantation on resilience and potential for RV-reverse remodeling. This could be taken as a basis to test the clinical benefit of additional mitral valve surgery in a selected subset of dilated cardiomyopathy (e.g. with preoperative TAPSE ≤ 14mm). On the other hand, it has been shown that uncorrected moderate to high-grade MI during LVAD implantation in patients with ischemic CMP is not a risk factor for prognosis and resilience, these are rather determined by the ischemic genesis of end-stage heart failure itself. Result In a future randomized trial, CMP etiology should be considered, as different mechanisms of reverse remodeling may be present under LVAD therapy. The baseline situation of the right ventricle at the time of LVAD implantation, as described by TAPSE, should also be considered in order to identify a subgroup that can benefit prognostically and physically performance from additional mitral valve surgery during LVAD implantation.