Lack of Nocturnal Blood Pressure Reduction Increases the Risk of Stroke in Patients on Left Ventricular Assist Device Support.

Lack of nocturnal blood pressure (BP) reduction (BP dipping) has been associated with cerebrovascular and cardiovascular events in the general population. However, the effect of a deranged circadian BP variability between day and night has never been studied in patients on left ventricular assist device (LVAD) support, where stroke still represents a major complication. We hypothesized that decreased BP dipping significantly increases the risk of stroke in patients on LVAD support. HeartMate II (HMII) outpatients were prospectively studied with an ambulatory BP monitor (Mobil-O-Graph) previously validated in this patient population. Systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were recorded every 30 minutes during the day and every hour during the night for 24 hours. Circadian patterns, expressed as the percentage of nocturnal SBP, DBP, and MAP reduction from daytime values, were assessed in Cox regression models with stroke as primary endpoint. 29 patients were studied (age 59 ±15 yrs, 76% male, 38% ischemic, 69% DT). 6 patients (20%) experienced a stroke 879±591 days post LVAD implant. Nocturnal reductions of SBP, DBP, and MAP were 5.0 ± 6.1%, 5.0 ± 5.6% and 5.0 ± 5.5%, respectively. Preserved nocturnal reductions of SBP (HR 0.790 [95% CI 0.658 - 0.949]), DBP (HR 0.707 [95% CI 0.559 - 0.894]) and MAP (HR 0.703 [95% CI 0.554 - 0.894]) were associated with a decreased risk of stroke. When patients were grouped by the median nocturnal reduction in MAP (5.4%), patients with reduced dipping had a significantly greater risk of stroke (Figure 1). This study is the first to indicate that reduced BP dipping at night increases the risk of stroke in patients on HMII support. Further studies are warranted to investigate, mechanistically, the relationship between reduced BP dipping and sympathetic nervous system activation, and, clinically, its association with the risk of stroke in patients on HM3 support. [ABSTRACT FROM AUTHOR]