The quest for permanent ventricular assistance: the role of aortic counterpulsation

Temporary aortic counterpulsation is used routinely for the management of cardiogenic shock. By the perseverance of several investigators, permanent aortic counterpulsation is close to becoming a clinical reality. The initial clinical experience with permanent aortic counterpulsation (KCV) has demonstrated that it can be implanted with very low peri-operative morbidity and mortality. It is a novel non-obligatory device that has several advantages over other existing devices. There is no need for anti-coagulation and no valves or internal electronics that could fail and force VAD replacement. The control algorithm is simple, as the device is triggered "on-demand" by the electrical activity of the native heart. Furthermore, it is non-obligatory, so it can be turned on/off at will by the patient without increasing the risk of thromboembolic events. The disadvantages are that it provides only "partial" support. It increases cardiac output by approximately 40% depending on the afterload condition of the patient. It depends upon native heart activity to function and cannot be placed in patients with severe biventricular function, uncontrolled tachyarrhythmias, or with native valvular disease. However, the degree of support obtained seems sufficient to reverse the heart failure syndrome, improve end-organ dysfunction and remove inotrope dependency. The KCV is designed for intervention in NYHA class IV patients before there is severe biventricular failure or lack of any myocardial reserve. It would not be an acute recovery device or one in which IABP pumping does not improve hemodynamics. The KCV can be considered equivalent to a mechanical, permanent, non-energy depleting inotrope and may have a role in improving the length and quality of life in patients with end stage heart failure. By treating advanced CHF early, the KCV may reduce the number of patients progressing towards cardiac replacement therapy with transplantation or a total artificial heart.