Left Ventricular Unloading Using an Impella CP Improves Coronary Flow and Infarct Zone Perfusion in Ischemic Heart Failure

Background-Delivering therapeutic materials, like stem cells or gene vectors, to the myocardium is difficult in the setting of ischemic heart failure because of decreased coronary flow and impaired microvascular perfusion (MP). The aim of this study was to determine if mechanical left ventricular (LV) unloading with the Impella increases coronary flow and MP in a subacute myocardial infarction. Methods and Results-Anterior transmural myocardial infarction (infarct size, 26.0 +/- 3.4\%) was induced in Yorkshire pigs. At 2 weeks after myocardial infarction, 6 animals underwent mechanical LV unloading by Impella, whereas 4 animals underwent pharmacological LV unloading using sodium nitroprusside for 2 hours. LV unloading with Impella significantly reduced end-diastolic volume (-16 +/- 11mL, P=0.02) and end-diastolic pressure (EDP; -32 +/- 23 mm Hg, P=0.03), resulting in a significant decrease in LV end-diastolic wall stress (EDWS) (infarct: 71.6 +/- 14.7 to 43.3 +/- 10.8 kdynes/cm(2) [P=0.02]; remote: 66.6 +/- 20.9 to 40.6 +/- 13.3 kdynes/cm(2) [P=0.02]). Coronary flow increased immediately and remained elevated after 2 hours in Impella-treated pigs. Compared with the baseline, MP measured by fluorescent microspheres significantly increased within the infarct zone (109 +/- 81\%, P=0.003), but not in the remote zone. Although sodium nitroprusside effectively reduced LV-EDWS, 2 (50\%) of sodium nitroprusside-treated pigs developed profound systemic hypotension. A significant correlation was observed between the infarct MP and EDWS (r(2)=0.43, P=0.03), suggesting an important role of EDWS in regulating MP during LV unloading in the infarcted myocardium. Conclusions-LV unloading using an Impella decreased EDWS and increased infarct MP without hemodynamic decompensation. Mechanical LV unloading is a novel and efficient approach to increase infarct MP in patients with subacute myocardial infarction.This study was partly supported by a research grant from ABIOMED Inc (Danvers, MA) (Ishikawa); National Institutes of Health (NIH) grants R01 HL139963 (Ishikawa) and HL117505, HL119046, HL129814, 128072, HL131404, R01HL135093, and P50 HL112324 (Hajjar); American Heart Association-Scientist Development Grant 17SDG33410873 (Ishikawa); and 2 Transatlantic Fondation Leducq grants. Bikou was supported by the Deutsche Herzstiftung. We would like to acknowledge the Gene Therapy Resource Program of the National Heart, Lung, and Blood Institute, NIH.S

Echocardiographic Left Ventricular Mass Estimation: Two-Dimensional Area-Length Method is Superior to M-Mode Linear Method in Swine Models of Cardiac Diseases

International audienceEchocardiography offers rapid and cost-effective estimations of left ventricular (LV) mass, but its accuracy in patients with cardiac disease remains unclear. LV mass was measured by M-mode-based linear method and two-dimensional echocardiography (2DE)-based area-length method in pig models and correlation with actual LV weight was assessed. Twenty-six normal, 195 ischemic heart disease (IHD), and 33 non-IHD HF pigs were included. A strong positive linear relationship to the actual LV weight was found with 2DE-based area-length method (r = 0.82, p < 0.001), whereas a moderate relationship was found with M-mode method in the overall population (r = 0.68, p < 0.001). Two correlation coefficients were significantly different (p < 0.001), and were driven mainly by incremental overestimation of LV mass in heavier hearts using the M-mode method. IHD and LV dilation were the factors contributing to overestimation using M-mode method. 2DE-based area-length method provides a better estimation of LV weight in swine models of HF, particularly in those with IHD