Abstract 2097: Acute Ventricular Unloading in Dogs with Chronic Heart Failure: Comparison Between Intra-Aortic Balloon Counterpulsation and Continuous Aortic Flow Augmentation

Abstract

Background: Continuous aortic flow augmentation (CAFA) therapy provided by the Cancion ® system (Orqis Medical, Inc.) for decompensated heart failure (HF)has been shown to effectively unload the left ventricle (LV) in dogs with chronic HF. In the present study, we compared the extent of acute LV unloading elicited by CAFA to that elicited by intra-aortic balloon counterpulsation (IABP) in normotensive dogs with HF produced by multiple sequential intracoronary microembolizations. Methods: Studies were performed in 6 dogs with HF. Each dog was studied with CAFA and with IABP. Studies were performed one week apart. For each study, therapy with CAFA or IABP was maintained for 4 hours. The Cancion system was positioned using a dual femoral approach configuration with constant pump flow of 250 ml/min thus superimposing an element of continuous flow on existing pulsatile aortic flow. In all dogs and with both devices, LV end-diastolic pressure (LVEDP), LV end-diastolic volume (EDV), LV end-systolic volume (ESV) and LV ejection fraction (EF) were measured at baseline prior to initiating therapy and were repeated at 2 hours and 4 hours after insituting CAFA or IABP. Results: Data (mean SEM) are shown in the table . Up to 4 hours of IABP had no significant effects on LVEDP, EDV, ESV or EF. In contrast, institution of CAFA for 4 hours significantly decreased LVEDP, EDV and ESV and significantly increased EF. Conclusions: In normotensive dogs with chronic HF and no epicardial coronary artery disease, acute therapy with IABP for up to 4 hours had no effect on LV unloading defined as a reduction in LV filling pressure and LV size. In the same cohort of dogs, CAFA therapy elicited marked LV unloading. These data indicate that CAFA is superior to IABP in achieving acute LV unloading in the setting of chronic HF not complicated by ongoing myocardial ischemia and/or cardiogenic shock.