All ETDs from UAB

Advisory Committee Chair

Gerald McGwin

Advisory Committee Members

Emily B Levitan

Russell L Griffin

Salpy V Pamboukian

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) School of Public Health


Ventricular assist devices (VAD) are used as a bridge to transplant and to increase the quality of life in advanced heart failure patients. The use of the VAD is not without risks itself, with an increased risk of thromboembolism, hemorrhage and death. Therefore, we aimed to (1) evaluate predictors of thromboembolism; (2) design a score to predict hemorrhages in VAD patients; and (3) evaluate the change in kidney function post-VAD implant and to investigate the relationship between kidney function and mortality in VAD patients using data collected from the University of Alabama at Birmingham Mechanical Circulatory Support Clinic. Over the 51.3 person-years of follow-up for the 115 participants, a total of 23 first thromboembolic events were encountered (Incidence Rate (IR) 4.5 events /10 patient years, 95% CI 29.1-66.2). There was an increased risk of thromboembolism with Early lactate dehydrogenase elevation, and estimated glomerular filtration rate <30 prior to VAD implantation while there was a decreased risk with good anticoagulation control. Out of 115 patients, total of 36 patients experienced a hemorrhage during the first year (Incidence Rate 70 per 100 person years (95%CI 50-96). Patients with a VAD bleeding risk score ≥3 have the highest risk of hemorrhage compared to the 3 fold increased risk of hemorrhage for patients with a HAS-BLED score of ≥ 3 and the 2.5 fold increased risk with an extended HAS-BLED score of ≥3. In the 228 patients, kidney function improves post implant with improvement in kidney function maintained over 1 year for all patients except those with CKD Stage 5 at baseline. Age at implant was the only statistically significant predictor of sustained improvement in kidney function. Regardless of baseline CKD stage, most patients experience an improvement in CKD stage after VAD implantation. Despite improvement in kidney function post VAD implant, patients with CKD stage 3b, 4 or 5 prior to VAD are at an increased risk of mortality post-VAD implantation. In conclusion, this study identifies predictors of thromboembolism, creates a VAD specific bleeding risk score and highlights how pre-VAD kidney function is an important risk factor for mortality post-VAD.

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