Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia; St Vincent's Clinical School, UNSW, Sydney, Australia.
Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia.
J Heart Lung Transplant. 2024 Mar;43(3):420-431. doi: 10.1016/j.healun.2023.10.004. Epub 2023 Oct 14.
Left ventricular assist device (LVAD) support offers remodeling potential in some patients. Our goal was to use noninvasively derived pressure-volume (PV) loops to understand the effect of demographic and device variables on serial changes in cardiac function under pump support.
Thirty-two consecutive Medtronic HeartWare Ventricular Assist Device (HVAD) patients (mean 55.9 ± 12.3 years, 81.3% male) were prospectively recruited. Single-cycle ventricular pressure and volume were estimated using a validated algorithm. PV loops (n = 77) and corresponding cardiac chamber dynamics were derived at predefined postimplant timepoints (1, 3, 6 months). Changes in PV loop parameters sustained across the 6-month period were characterized using mixed-effects modeling. The influence of demographic and device variables on the observed changes was assessed.
Across a 6-month period, the mean ventricular function parameters remained stable. Significant predictors of monthly improvement of stroke work include: lower pump speeds (2400 rpm vs 2500-2800 rpm) [0.0.051 mm Hg/liter/month (p = 0.001)], high pulsatility index (>1.0 vs <1.0) [0.052 mm Hg/liter/month (p = 0.012)], and ischemic cardiomyopathy indication for LVAD implantation (vs nonischemic) [0.0387 mm Hg/liter/month (p = 0.007)]. Various other cardiac chamber function parameters including cardiac power, peak systolic pressure, and LV elastance also showed improvements in these cohorts.
Factors associated with improvement in ventricular energetics and hemodynamics under LVAD support can be determined with noninvasive PV loops. Understanding the basis of increasing ventricular load to optimize myocardial remodeling may prove valuable in selecting eligible recovery candidates.
左心室辅助装置（LVAD）支持在某些患者中提供了重塑的潜力。我们的目标是使用无创衍生的压力-容积（PV）环来了解人口统计学和设备变量对泵支持下心脏功能的连续变化的影响。
前瞻性招募了 32 名连续的美敦力心脏辅助心室辅助装置（HVAD）患者（平均年龄 55.9±12.3 岁，81.3%为男性）。使用经过验证的算法估计单个心动周期心室压力和容积。在预设的植入后时间点（1、3、6 个月）获得 PV 环（n=77）和相应的心脏腔室动力学。使用混合效应模型描述 6 个月期间持续的 PV 环参数变化。评估人口统计学和设备变量对观察到的变化的影响。
在 6 个月的时间内，平均心室功能参数保持稳定。stroke work 每月改善的显著预测因素包括：较低的泵速（2400rpm 与 2500-2800rpm）[0.0.051mm Hg/liter/month（p=0.001）]、较高的脉动指数（>1.0 与 <1.0）[0.052mm Hg/liter/month（p=0.012）]以及 LVAD 植入的缺血性心肌病适应证（与非缺血性）[0.0387mm Hg/liter/month（p=0.007）]。这些队列中的各种其他心脏腔室功能参数，包括心脏功率、收缩压峰值和 LV 弹性也显示出改善。
可以通过无创 PV 环确定 LVAD 支持下心室能量和血液动力学改善的相关因素。了解增加心室负荷以优化心肌重塑的基础可能有助于选择有资格恢复的候选者。
