Low Blood Pressure Threshold for Adverse Outcomes During Left Ventricular Assist Device Support

Abstract

It has been suggested that maintaining low mean arterial pressure (MAP) in left ventricular assist device (LVAD) recipients is associated with a reduced risk of stroke/death. However, the lower limit of the optimal MAP range has not been established. We aimed to identify this lower limit in a contemporary cohort of LVAD recipients with frequent longitudinal MAP measurements. We analyzed 86,651 MAP measurements in 309 patients with an LVAD (32% LVADs with full magnetic levitation of the impeller) at a tertiary medical center during a mean follow-up of 1.7 ± 1.1years. Cox proportional hazards regression modeling was used to study the association of serial MAP measurements with stroke/death within 3years after index discharge. Multivariate analysis identified MAP ≤75mmHg, compared with MAP >75mmHg, as the low MAP threshold associated with increased risk of death (hazard ratio [HR] 4.74, 95% confidence interval [CI] 2.85 to 7.87, p<0.001), stroke (HR 2.72;, 95% CI 1.39 to 5.33, p=0.01), and stroke/death (HR 4.45, 95% CI 2.83 to 6.99, p<0.001). The risk associated with MAP ≤75mmHg was consistent in subgroups categorized by age, gender, race, device type, renal function, right-sided heart failure, and blood pressure medications. In conclusion, our findings suggest that maintaining MAP ≤75mmHg during long-term follow-up in LVAD recipients is associated with increased risk of stroke/death regardless of risk factors or medical management.