Presence and impact of anemia in patients supported with left ventricular assist devices

Abstract

Background: Data on anemia and its effects on patients supported with continuous-flow left ventricular assist devices (LVADs) are lacking.

Objectives: This study sought to describe the presence of anemia over time and investigate its association with mortality, quality of life, exercise capacity, and adverse events in LVAD patients.

Methods: Adults receiving durable LVADs between 2008 and 2017 were identified from the INTERMACS database. The full cohort was stratified according to anemia severity (no anemia, mild, and moderate-severe).

Results: The analysis of 19,509 patients (females: 21.2%, age: 56.9 ± 12.9 years) showed that moderate-severe anemia affected 45.2% of patients at baseline, 33.5% of them at 6 months, and 32.3% in the fourth year after implantation. The presence of normal hemoglobin was 24.4% before surgery, 32.5% at 6 months, and 36.6% at 4 years after implantation. Multivariable linear mixed-effect regression revealed that the average hemoglobin over time was significantly lower (β, -0.233, 95% confidence interval (CI): -0.282 to -0.185), and the reduction of hemoglobin over time was bigger (β, -0.032 95% CI: -0.035 to -0.028) for LVAD nonsurvivors compared with LVAD survivors. Adjusted Cox regression showed that the severity of preimplant anemia was associated with higher mortality (HR, mild: 1.19; 95% CI: 1.05-1.35 and moderate-severe: 1.44; 95% CI: 1.28-1.62), with similar results in competing risk regression. Anemia progression during follow-up was associated with decreased Kansas City Cardiomyopathy Questionnaire scores and shorter 6-minute walk distances.

Conclusions: In patients supported with LVADs, anemia is a frequent comorbidity, and deterioration over time is associated with poor prognosis.

Keywords: INTERMACS registry; anemia; left ventricular assist device.