LAUSR

Purpose Optimal dose of aspirin for Heartmate 3 (HM 3) LVAD patients is still not known. Recently low dose aspirin (81mg compared to 325mg) has shown to be efficacious. Randomized control trial with no dose aspirin is underway. However, platelet inhibition can be still achieved with less than low dose aspirin. So we looked into safety and efficacy of a very low dose aspirin ( Methods We did retrospective analysis of HM3 patients implanted in our institution (2015- 2020). Patients who were on less than 81mg of aspirin/day were identified. Thromboelastogram (TEG) was used to assess response to aspirin. We compared the number of thromboembolic events, bleeding events, LDH, and hematocrit before and after the dose change, with the patients being their own controls, using paired t test. Results In our program, we follow 35 patients on HM3. Most of them 24(68.6%) receive > 81 mg of aspirin daily. We Identified 11 patients on less than 81mg of aspirin. The mean age of this cohort was 51.18 years, 7 were Male. Out of the 11, 3 patients were on aspirin 40.5 mg every other day, 3 on 40.5 mg every day, 4 on 81mg every other day and one patient was not on any aspirin. Reason for dose alteration was adequate inhibition noted on TEG in 5 patients and bleeding in 6 patients (4 out of 6 for gastrointestinal bleed). Mean duration of follow up was 22.57±18months. Six patients in this cohort were on standard warfarin protocol with the INR goal 2-3 and one patient was not on any warfarin. The follow-up on a very low ASA dose was 13.7±8.6 months. There were no pump thrombosis or other thromboembolic events either before or after the dose change. There was no significant difference in LDH levels before (225.2±24.3) or after (220.1±27.8) p=0.7, hematocrit before 33.6+/-9.9 or after 35.0+/-8.1, P=0.08, aspirin dose change. Arachidonic Acid inhibition on thromboelastogram was less than 80% in 7 patients and 5 of them had inhibition less than 50%. Conclusion A very low dose of aspirin (