Commentary: Successful Combined Use of the Impella Recover 2.5 Device and Intraaortic Balloon Pump Support for Cardiogenic Shock After Acute Myocardial Infarction

Abstract

Enhancing coronary flow, reduction of after-load, and preload positively influences recovery of the left ventricle after acute myocardial infarction.1 Devices such as intra-aortic balloon pump (IABP) and left ventricular assist device (LVAD) have been designed in that manner; IABP increases coronary flow and reduces after-load, whereas LVAD increases coronary flow and reduces preload.1,2 Recent meta-analysis of controlled trials comparing both devices showed similar 30-day survival despite higher cardiac index, mean arterial pressure, and lower pulmonary capillary wedge pressure (PCWP) in patients treated with LVAD, when compared with those treated with IABP.2 The concept of combining the benefits of both LVAD and IABP have been tested experimentally3 where the use of LVAD alone increased the coronary flow by 47%, and the use of IABP alone increased coronary flow by 13% and carotid flow by 16%. Concurrent use of both devices increased coronary flow by 33% and carotid flow by 21%. Twenty-five percent reduction of myocardial oxygen demand was attributed to the use of IABP.3 In this issue of the journal, Wiktor et al.4 reports the use of LVAD (Impella Recover 2.5) and the intraaortic balloon pump in a 67-year-old patient with post-St-elevation myocardial infarction (STEMI) cardiogenic shock and an ejection fraction of 10% as a bridge to recovery. The patient made a good recovery and is in New York Heart Association (NYHA) class II 16 months after the diagnosis of intractable cardiogenic shock. One inherent fault in current LVAD technology, however, is increased after-load, which is detrimental to myocardial recovery and may accelerate negative ventricular remodeling. This is more exaggerated if the LVAD device is implanted in the left ventricular outflow (LVOT), thereby mimicking a state of LVOT obstruction. In previous experiments,5 we have tested the use of IABP combined with synchronized left atrial-to-aorta LVAD. The use of synchronized LVAD alone (1 ml/kg in 40-kg sheep) was associated with a rise in aortic pressure that persisted for a number of subsequent cardiac cycles (Figure 1A). Such detrimental increase in after-load was prevented by concurrent use of IABP (Figure 1B). Achieving a more physiological VAD requires further studies using novel counterpulsation/LVAD technology. The impact of this approach, versus LVAD or IABP alone, on infarct size will determine the ideal therapeutic approach to patients with cardiogenic shock due to acute left ventricular failure, a disease that is fatal in 78% of the cases.Figure 1. A:: LA to aorta VAD-assisted cardiac cycle (arrow); note the increase in aortic pressure that persisted for a number of subsequent (unassisted) cardiac cycles. B: IABP-assisted cardiac cycle, combined IABP + LVAD (1 ml/kg body weight)-assisted cardiac cycle, and unassisted cardiac cycles. LA, left atrium; VAD, ventricular assist device.