Abstract 1819: Left Atrial Reverse Remodeling in Dogs with Moderate and Advanced Heart Failure Treated with the Acorn Cardiac Support Device
Background: Assessment of global LV remodeling is a key component of evaluating the efficacy of therapies for the treatment of chronic heart failure (HF). The effect of pharmacologic or device therapies on global left atrial (LA) remodeling in HF, while important, is not often examined. Long-term therapy with the Acorn Cardiac Support Device (CSD) was shown to prevent or reverse LV remodeling in dogs with HF. This study examined the effects of the CSD on global LA remodeling in dogs with moderate HF and dogs with advanced HF.
Methods: Studies were performed in 24 dogs with coronary microembolization-induced HF. Of these, 12 had moderate HF (EF 30% to 40%) and 12 advanced HF (EF ≤ 25%). In each group, the CSD was implanted in 6 dogs and the other 6 served as concurrent controls. Dogs were followed for 3 months in the moderate group and 6 months in the advanced HF group. LA maximal volume (LAVmax), LA volume at the onset of the p-wave (LAVp), LA minimal volume (LAVmin), LA active emptying volume (LAAEV) and LA active emptying fraction (LAAEF) were measured from 2-dimensional echocardiograms obtained prior to CSD implantation (PRE) and at the end of the treatment period (POST).
Results: Data are shown in the table⇓. LA volumes increased and LA function deteriorated in control dogs but did not significantly change in CSD-treated dogs. Treatment effect (Δ) comparisons showed that CSD therapy significantly decreased LA volumes (ΔLAVmax: 2.9±1.3 vs. −3.3±0.7 ml, p<0.01; 0.4±0.9 vs. −7.8±1.8 ml, p<0.01) and improved LA function (ΔLAAEF: −1.9±1.3 vs. 6±1.5 %, p<0.01; −3.1±1.7 Vs. 2.4±1 %, p<0.05) in the moderate HF and advanced HF groups respectively.
Conclusions: Progressive LA enlargement and LA functional deterioration occurs in untreated dogs with HF. Monotherapy with the CSD prevents LA enlargement and improves LA function in dogs with moderate and advanced HF. The results suggest that the CSD, placed around the ventricles, can have secondary beneficial effects on progressive LA remodeling.