Smedira Nicholas G, Blackstone Eugene H, Ehrlinger John, Thuita Lucy, Pierce Christopher D, Moazami Nader, Starling Randall C
Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute.
Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute; Kaufman Center for Heart Failure; Department of Quantitative Health Sciences, Research Institute.
J Heart Lung Transplant. 2015 Dec;34(12):1527-34. doi: 10.1016/j.healun.2015.10.027.
Data from 3 institutions revealed an abrupt increase in HeartMate II (Thoratec) pump thrombosis starting in 2011, associated with 48% mortality at 6 months without transplantation or pump exchange. We sought to discover if the increase occurred nationwide in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data, and if so (1) determine if accelerated risk continued, (2) identify predictors, (3) investigate institutional variability, and (4) assess mortality after pump thrombosis.
From April 2008 to June 2014, 11,123 HeartMate II devices were implanted at 146 institutions. Machine learning, non-parametric Random Forests for Survival was used to explore risk-adjusted thrombosis based on 87 pre-implant and implant variables, including implant date.
A total of 995 pumps thrombosed, with risk peaking within weeks of implant. The risk-adjusted increase in pump thrombosis began in 2010, reached a maximum in 2012, and then plateaued at a level that was 3.3-times higher than pre-2010. Pump exchange, younger age, and larger body mass index were important predictors, and institutional variability was largely explained by implant date, patient profile, and duration of support. The probability of death within 3 months after pump thrombosis was 24%.
Accelerated risk of HeartMate II thrombosis was confirmed by Interagency Registry for Mechanically Assisted Circulatory Support data, with risk subsequently leveling at a risk-adjusted rate higher than observed pre-2010. This elevated thrombosis risk emphasizes the need for improved mechanical circulatory support systems and post-market surveillance of adverse events. Clinicians cognizant of these new data should incorporate them into their and their patients' expectations and understanding of risks relative to those of transplantation and continued medical therapy.
来自3家机构的数据显示，自2011年起，HeartMate II（Thoratec）泵血栓形成突然增加，在未进行移植或更换泵的情况下，6个月时死亡率达48%。我们试图通过机构间机械辅助循环支持注册中心（INTERMACS）的数据来发现这种增加是否在全国范围内出现，如果是，（1）确定加速风险是否持续，（2）识别预测因素，（3）调查机构间差异，以及（4）评估泵血栓形成后的死亡率。
2008年4月至2014年6月，146家机构植入了11,123台HeartMate II装置。使用机器学习、用于生存分析的非参数随机森林算法，基于87个植入前和植入时的变量（包括植入日期）来探索风险调整后的血栓形成情况。
共有995台泵发生血栓形成，风险在植入后数周内达到峰值。泵血栓形成的风险调整后增加始于2010年，2012年达到最高，然后稳定在比2010年前高3.3倍的水平。泵更换、年轻和较高的体重指数是重要的预测因素，机构间差异在很大程度上由植入日期、患者特征和支持时间来解释。泵血栓形成后3个月内死亡的概率为24%。
机构间机械辅助循环支持注册中心的数据证实了HeartMate II血栓形成的加速风险，随后风险稳定在高于2010年前观察到的风险调整率水平。这种升高的血栓形成风险强调了改进机械循环支持系统和对不良事件进行上市后监测的必要性。了解这些新数据的临床医生应将其纳入他们及患者对与移植和持续药物治疗相关风险的预期和理解中。
