Halder Laura C, Richardson Laura B, Garberich Ross F, Zimbwa Peter, Bennett Mosi K
From the *Department of Pharmacy, University of Iowa Hospitals and Clinics, Iowa City, IA (Employed by Abbott Northwestern Hospital During the Development of This Article); †Sanofi US, Bridgewater, NJ (Employed by Abbott Northwestern Hospital During the Development of This Article); ‡Heart Failure Section, Minneapolis Heart Institute Foundation, Research, Minneapolis, MN; and §Heart Failure Section, Abbott Northwestern Hospital, Minneapolis Heart Institute, Minneapolis, MN.
ASAIO J. 2017 Jan/Feb;63(1):37-40. doi: 10.1097/MAT.0000000000000449.
Left ventricular assist devices (LVADs) require anticoagulation therapy with vitamin K antagonists to reduce the risk of thrombotic events. The quality of anticoagulation may be assessed by the time in therapeutic range (TTR). We analyzed a retrospective cohort of LVAD patients at a single institution from January 2012 to September 2014. Primary outcomes included TTR during the study time period and TTR 30 days preceding a bleeding or thrombotic event. Fifty-one patients (mean age 57.0 ± 14.6 years; 78% male) had an overall TTR of 52%. Median international normalized ratio (INR) preceding a bleeding and thrombotic event was 2.7 and 2.2, respectively (p = 0.049). In the 30 days before an event, patients with a bleeding event were more likely to be on low-dose aspirin (37% vs. 12%; p = 0.018) and spend a higher proportion of time above therapeutic range (41% vs. 17%; p = 0.007) compared with those with thrombotic events. The association between a greater percentage of time above therapeutic range in the 30 days before a bleeding event demonstrates the importance of avoiding a supratherapeutic INR in the LVAD patient population and the usefulness of TTR as a measure of the overall quality of anticoagulation and monitoring in an LVAD cohort.
左心室辅助装置（LVADs）需要使用维生素K拮抗剂进行抗凝治疗，以降低血栓形成事件的风险。抗凝质量可通过治疗范围内时间（TTR）来评估。我们分析了2012年1月至2014年9月在一家机构的LVAD患者回顾性队列。主要结局包括研究期间的TTR以及出血或血栓形成事件前30天的TTR。51例患者（平均年龄57.0±14.6岁；78%为男性）的总体TTR为52%。出血和血栓形成事件前的国际标准化比值（INR）中位数分别为2.7和2.2（p = 0.049）。在事件发生前30天，与血栓形成事件患者相比，出血事件患者更可能服用低剂量阿司匹林（37%对12%；p = 0.018），且在治疗范围以上的时间占比更高（41%对17%；p = 0.007）。出血事件前30天治疗范围以上时间占比更高之间的关联表明，在LVAD患者群体中避免INR超治疗水平的重要性，以及TTR作为LVAD队列中抗凝总体质量衡量指标和监测指标的有用性。
