Circulatory support with a direct cardiac compression device: A less invasive approach with the AbioBooster device

Abstract

TX R efractory cardiogenic shock is an important cause of death in patients after acute myocardial infarction (AMI), therapeutic percutaneous cardiac catheterization, and cardiac surgery. Of the 1.1 million AMI cases annually, 7% to 10% have cardiogenic shock, which has a 50% to 60% in-hospital mortality.1 The value of short-term circulatory support with currently available assist devices is drastically reduced by thromboembolic, hemorrhagic, and infectious devicerelated complications.2 The concept of direct cardiac compression (DCC), first introduced in 1965,3 is simple and elegant, with several advantages over intravascular ventricular assist devices (VAD) in current use. Use of non-blood contacting DCC systems would avoid cardiopulmonary bypass and bleeding complications and would be technically simpler to institute, allowing more widespread use. We evaluated a pneumatic DCC device, the AbioBooster, designed and fabricated by ABIOMED, Inc (Danvers, Mass). This device consists of inflatable polyurethane cylinders wrapped within a silicone-coated polytetrafluoroethylene fabric. Air pumped into and out of the wrap causes contraction and dilatation of its circumference (Figure 1). Twelve sheep studies were performed in nine short-term and three 4-week survival experiments. The effects of the wrap after induced cardiogenic shock (esmolol β-blockade with norepinephrine) and ventricular fibrillation were characterized. To create a reproducible model of heart failure, we used a continuous infusion of a short-acting β-blocker, esmolol. An esmolol drip was started at 10 mg/min and titrated to maintain a descending aortic blood flow at 1.0 L/min or less. We evaluated the impact of the device on underlying coronary artery bypass grafts (CABGs) by performing bypasses from the left internal thoracic artery to the left anterior descending artery (n = 1) or first diagonal artery (n = 2) and from the innominate artery to the first obtuse marginal artery (n = 3) using a reversed saphenous vein graft before device application.