Weil Brian R, Konecny Filip, Suzuki Gen, Iyer Vijay, Canty John M
Department of Physiology and Biophysics, The Clinical and Translational Research Center of the University at Buffalo, Buffalo, New York.
Department of Surgery, McMaster University, Hamilton, Ontario, Canada.
JACC Cardiovasc Interv. 2016 Nov 28;9(22):2292-2303. doi: 10.1016/j.jcin.2016.08.037. Epub 2016 Oct 26.
The aim of this study was to directly compare the hemodynamic effects of 2 contemporary percutaneous mechanical circulatory support devices in a porcine model of acute myocardial infarction.
Percutaneous support devices offer the ability to unload the ischemic left ventricle, but the comparative hemodynamic effects of contemporary platforms are unclear.
Yorkshire swine (mean weight 76 ± 2 kg; n = 7) were instrumented with a left ventricular (LV) pressure-volume (PV) catheter and subjected to a 2-h coronary occlusion. Hemodynamic parameters and PV-derived indexes of LV performance were assessed 30 min after reperfusion and during LV support with Impella CP (ICP) and TandemHeart devices (in randomized order) at comparable flow rates.
Myocardial infarction produced a rightward shift of the PV loop and increased LV end-diastolic pressure (from 9 ± 2 mm Hg to 15 ± 2 mm Hg; p = 0.04). After reperfusion, both devices maintained aortic pressure, shifted the PV loop to the left, and decreased LV end-diastolic pressure (ICP vs. TandemHeart; 11 ± 1 mm Hg vs. 7 ± 4 mm Hg; p = 0.04). However, only TandemHeart elicited significant reductions in native LV stroke volume (from 75 ± 7 ml to 39 ± 7 ml; p < 0.01), dP/dt (from 988 ± 77 mm Hg/s to 626 ± 42 mm Hg/s; p < 0.01), stroke work (from 0.70 ± 0.03 J to 0.26 ± 0.05 J; p < 0.01), PV area (from 0.95 ± 0.11 J to 0.47 ± 0.10 J; p < 0.01), and pre-load-recruitable stroke work slope (from 41.7 ± 2.8 J/ml to 30.6 ± 3.9 J/ml; p = 0.05).
At comparable device flow rates, TandemHeart decreased LV pre-load, native LV stroke volume, and myocardial contractility to a greater degree than ICP. Reductions in load-independent indexes of LV performance indicate favorable effects on myocardial oxygen balance and support further study of TandemHeart in clinical scenarios requiring mechanical support in the setting of acute myocardial ischemia.
本研究旨在直接比较两种当代经皮机械循环支持装置在猪急性心肌梗死模型中的血流动力学效应。
经皮支持装置能够减轻缺血左心室的负荷，但当代不同平台的相对血流动力学效应尚不清楚。
选用约克夏猪（平均体重76±2kg；n = 7），植入左心室（LV）压力-容积（PV）导管，并进行2小时冠状动脉闭塞。在再灌注30分钟后以及使用Impella CP（ICP）和TandemHeart装置以可比流速进行左心室支持期间，评估血流动力学参数和基于PV得出的左心室功能指标。
心肌梗死导致PV环向右移位，左心室舒张末期压力升高（从9±2mmHg升至15±2mmHg；p = 0.04）。再灌注后，两种装置均维持主动脉压力，使PV环向左移位，并降低左心室舒张末期压力（ICP与TandemHeart相比；11±1mmHg与7±4mmHg；p = 0.04）。然而，只有TandemHeart能显著降低左心室自身的每搏输出量（从75±7ml降至39±7ml；p < 0.01）、dP/dt（从988±77mmHg/s降至626±42mmHg/s；p < 0.01）、每搏功（从0.70±0.03J降至0.26±0.05J；p < 0.01）、PV面积（从0.95±0.11J降至0.47±0.10J；p < 0.01）以及前负荷可募集每搏功斜率（从41.7±2.8J/ml降至30.6±3.9J/ml；p = 0.05）。
在装置流速可比的情况下，TandemHeart比ICP更能显著降低左心室前负荷、左心室自身每搏输出量和心肌收缩力。左心室功能负荷独立指标的降低表明对心肌氧平衡有有利影响，并支持在急性心肌缺血情况下需要机械支持的临床场景中进一步研究TandemHeart。
