In Vitro Comparison of Support Capabilities of Intra‐Aortic Balloon Pump and Impella 2.5 Left Percutaneous

Abstract

The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in management, the advantages of the Impella 2.5 LP are yet to be established. The aim of this study was to evaluate the benefits of the 40 cc IABP and the Impella 2.5 LP operating at 47,000 rpm in vitro, and compare their circulatory support capabilities in terms of cardiac output, coronary flow, cardiac stroke work, and arterial blood pressure. Clinical scenarios of cardiogenic preshock and cardiogenic shock (CS), with blood pressure depression, lowered cardiac output, and constant heart rate of 80 bpm, were modeled in a model-controlled mock circulation, featuring a systemic, pulmonary, and coronary vascular bed. The ventricles, represented by servomotor-operated piston pumps, included the Frank-Starling mechanism. The systemic circulation was modeled with a flexible tube having close-to-human aortic dimensions and compliance properties. Proximally, it featured a branch mimicking the brachiocephalic arteries and a physiological correct coronary flow model. The rest of the systemic and pulmonary impedance was modeled by four-element Windkessel models. In this system, the enhancement of coronary flow and blood pressure was tested with both support systems under healthy and pathological conditions. Hemodynamic differences between the IABP and the Impella 2.5 LP were small. In our laboratory model, both systems approximately yielded a 10% cardiac output increase and a 10% coronary flow increase. However, since the Impella 2.5 LP provided significantly better left ventricular unloading, the circulatory support capabilities were slightly in favor of the Impella 2.5 LP. On the other hand, pulsatility was enhanced with the IABP and lowered with the Impella 2.5 LP. The support capabilities of both the IABP and the Impella 2.5 LP strongly depended on the simulated hemodynamic conditions. Maximum hemodynamic benefits were achieved when mechanical circulatory support was applied on a simulated scenario of deep CS.

Effects of Intra‐Aortic Balloon Pump Timing on Baroreflex Activities in a Closed‐Loop Cardiovascular Hybrid Model

“…IABP modeling can be performed by connecting the IABP to a circulatory hydraulic model (20)(21)(22) or connecting a computational circulatory model to a computational model of the balloon itself (23). In the present work, we advance the hybrid model of the cardiovascular system (9), by including a specific computational representation for baroreflex, and examine its activity in connection to the IABP.…”

What's New in Shock, April 2020?

“…However, as described above, the CRISP-AMI study (101) found no difference in mean final infarct size between STEMI patients (not complicated by cardiogenic shock) who received routine IABP compared with those who did not. Animal studies of LV unloading with Impella appeared more favorable (56,(119)(120)(121) and a preliminary clinical report of Impella for infarct size reduction in the STEMI setting was encouraging (122). The MINI-AMI (Minimizing Infarct Size with Impella 2.5…”

2015 SCAI/ACC/HFSA/STS Clinical Expert Consensus Statement on the Use of Percutaneous Mechanical Circulatory Support Devices in Cardiovascular Care

“…However, as described above, the CRISP-AMI study [101] found no difference in mean final infarct size between STEMI patients (not complicated by cardiogenic shock) who received routine IABP compared with those who did not. Animal studies of LV unloading with Impella appeared more favorable [56,[119][120][121] and a preliminary clinical report of Impella for infarct size reduction in the STEMI setting was encouraging [122]. The Minimizing Infarct Size with Impella 2.5 Following PCI for Acute Myocardial Infarction (MINI-AMI) trial sought to measure this benefit, but this study was terminated before completion [123].…”