Abstract 3060: Wrap Tightness Determines Rate and Degree of Reverse Ventricular Remodeling with Ventricular Restraint Therapy
Objective: We have developed an adjustable and measurable technique of ventricular restraint by placing a fluid-filled epicardial balloon around the entire ventricular surface. Wrap tightness is quantified by measuring balloon luminal pressure at end-diastole. In this study, the effect of wrap tightness on reverse remodeling in a chronic ovine model of HF was assessed.
Methods: HF developed in 9 ovine 2 months after ligation of diagonal coronary arteries. Ovine were divided into 3 equal groups: control, low restraint (1.5 mmHg), and high restraint (3.0 mmHg). Epicardial balloons were implanted and ventricular remodeling was evaluated over 2 more months with weekly echocardiography. Wrap tightness was measured weekly via a portacath. Change in LV EF, EDV, and wrap tightness was then assessed using repeated measures analysis of variance.
Results: Ventricular restraint decreased EDV and improved EF in all HF ovine. High restraint decreased EDV to a greater degree than low restraint. Wrap tightness decreased as the heart reverse remodeled. Reverse remodeling slowed. Peak reverse remodeling occurred after 21 days with high restraint and after 35 days with low restraint.
Conclusion: Ventricular restraint wrap tightness affects the rate and degree of improvement in LV EDV. Periodic adjustment of wrap tightness may be required for optimal restraint therapy efficacy.