Abstract P175: Selective Regional Injections of Alginate Hydrogel into Cardiac Veins Improve Left Ventricular Function and Reverse Chamber Remodeling in Dogs with Chronic Heart Failure

Background: Progressive LV enlargement and dysfunction are characteristics of heart failure (HF) and are associated with increased mortality and morbidity. We tested the hypothesis that selective regional injections of alginate hydrogel implants (AHI, Algisyl-LVR, Lonestar Heart, Inc.) into isolated segments of epicardial veins of the failing LV will increase LV wall thickness and lead to reduced LV size, lower LV wall stress and improved LV systolic and diastolic function. Methods: 12 dogs with coronary microembolization-induced HF (LV ejection fraction, EF nd diagonal branch and the 2 nd marginal branch of the cardiac epicardial veins were isolated by ligation with silk sutures. In 6 dogs, the isolated segments were each injected with 1.0 ml of AHI and in 6 dogs with normal saline (controls). LV ED volume (EDV), ES volume (ESV), EF, stroke volume (SV), ED wall stress (EDWS), deceleration time of early mitral inflow velocity (DT), and severity of functional mitral regurgitation (MR) were measured before therapy (Pre) and at 6 months after AHI or saline delivery (Post). The treatment effect (Δ) was calculated as the difference between Pre and Post. Results: In preliminary we showed that an intravenous injection of 1.0 ml AHI increased regional LV end-diastolic (ED) and end-systolic (ES) wall thickness by 5.8 ± 0.7 % and 9.0 ± 1.0 %, respectively. Compared to saline controls, treatment of HF dogs with AHI prevented the increase in EDV and significantly decreased ESV, EDWS and severity of functional MR (Table). In addition, AHI significantly increased LV EF, SV and DT indicating improved LV systolic and diastolic function (Table). Treatment with Alginate implants also showed a safe and non-arrhythmogenic chronic profile. Conclusion: LV reconstruction using selective regional injections of AHI into epicardial cardiac veins represents a safe novel approach for the treatment of advanced chronic HF.