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. 2016 May;9(5):e002680.
doi: 10.1161/CIRCHEARTFAILURE.115.002680.

Relationship Between Anticoagulation Intensity and Thrombotic or Bleeding Outcomes Among Outpatients With Continuous-Flow Left Ventricular Assist Devices

Michael E Nassif  1 , Shane J LaRue  2 , David S Raymer  1 , Eric Novak  1 , Justin M Vader  1 , Gregory A Ewald  1 , Brian F Gage  1
Affiliations

Relationship Between Anticoagulation Intensity and Thrombotic or Bleeding Outcomes Among Outpatients With Continuous-Flow Left Ventricular Assist Devices

Michael E Nassif et al. Circ Heart Fail. 2016 May.

Abstract

Background: We evaluated thrombotic and bleeding outcomes in patients with continuous-flow left ventricular assist devices (CF-LVADs), stratified by anticoagulation intensity. Previous studies of outpatients with CF-LVADs have suggested that target international normalized ratio (INR) values <2.5 (range, 2-3) may be used. However, recent studies reported an increase in pump thrombosis among CF-LVADs, especially within the first 6 months of implant.

Methods and results: We retrospectively reviewed 249 outpatients at our center who received a CF-LVAD between January 2005 and August 2013. Using Poisson models, we analyzed their 10 927 INRs to determine INR-specific rates of thrombotic (ischemic stroke and suspected pump thrombosis) and hemorrhagic (gastrointestinal bleeding and hemorrhagic stroke) events occurring outside of the hospital. In multivariate analyses, we adjusted for age, sex, atrial fibrillation, coronary disease, and LVAD type as time-dependent Cox proportional hazard models. During a mean follow-up of 17.6±13.6 months, thrombotic events occurred in 46 outpatients. The highest event rate (0.40 thrombotic events per patient-year) was in the INR range of <1.5, but INR values of 1.5 to 1.99 also had high rates (0.16 thrombotic events per patient-year). INR was inversely associated with thrombotic events (hazard ratio, 0.40; 95% confidence interval, 0.22-0.72; P=0.002). The optimal INR based on weighted mortality of thrombotic and bleeding events was 2.6.

Conclusions: INR is inversely related to thrombotic events occurring outside of the hospital among patients supported with CF-LVADs. INR values <2.0 increase the rate of thrombotic events occurring outside of the hospital among patients supported with CF-LVADs.

Keywords: atrial fibrillation; follow-up studies; hemorrhage; international normalized ratio stroke.

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Conflict of interest statement

Disclosures

GAE receives consulting fees from Thoratec. No other relevant conflicts. Content is solely the responsibility of the authors.

Figures

Figure 1
Figure 1
International normalized ratio (INR) measurements after hospital discharge with a left ventricular assist device (LVAD). The horizontal line in the middle of each box indicates the mean INR for the month; and the whiskers mark the standard deviation.
Figure 2
Figure 2
(A) Thrombotic and (B) hemorrhagic event rates as a function of international normalized ratio (INR) at time of event per total patient years in a given INR range.
Figure 2
Figure 2
(A) Thrombotic and (B) hemorrhagic event rates as a function of international normalized ratio (INR) at time of event per total patient years in a given INR range.
Figure 3
Figure 3
Thrombotic and hemorrhagic event rates as a function of international normalized ratio (INR) at time of event per total patient years.
See this image and copyright information in PMC

Comment in

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