Neither Time in Therapeutic Range nor Most Recent International Normalized Ratio (INR) Correlate with Adverse Events in Patients Supported by Continuous-Flow Left Ventricular Assist Devices

Abstract

Introduction Continuous-Flow Left Ventricular Assist Devices (CFLVADs) improve mortality and quality of life in end-stage cardiomyopathy patients. Adverse events however remain high. Hypothesis We hypothesize time in therapeutic range (TTR) correlates with adverse events compared to most recent INR. Methods The study group comprised of patients who suffered suspected/confirmed pump thrombosis, stroke or major bleeding event as defined by INTERMACS after ≥ 1 month at home with ≥ 1 month of INR values. Controls (CON) had at least 3 months of INR values after being home for 1 month from LVAD implant and who did not experience any adverse events (AE). Standard statistical methods were employed as indicated: Chi-square, Fishers Exact test, two-sample t-test, Wilcoxon Rank sum test, One way ANOVA and Kruskal Wallis Analysis. Patients with multiple adverse events were excluded. Results From June 2010 - December 2016, 132 patients underwent CFLVAD implantation at our institution who met entry criteria. Mean age was 57±13 yrs and 106 (80%) were male. Seventy-seven (58%) were implanted as bridge to transplant (BTT). There was no statistically significant difference in TTR (p=0.39, Table 1 ) or most recent INR (p=0.33, Table 2 ) prior to AE. Patients who suffered AEs were older than those who did not (59.3± 12 vs. 54.4±14.3 yrs, p=0.04). There was no association of AEs when stratified by gender, LVAD indication, LVAD device type, race, BMI or hospital length of stay (p=ns). Conclusions Neither time in therapeutic range nor most recent INR correlated with major bleeding, neurological dysfunction or pump thrombosis in CFLVAD patients in this analysis. Further investigation beyond strict INR control and anticoagulation is needed to reduce adverse events in this patient population.