Abstract WP405: Ultra-short-term Blood Pressure Variability is Increased in Ischemic Stroke Patients Compared to Controls

Abstract

Introduction: Systolic blood pressure variability (BPV) is increased after ischemic stroke and higher levels are associated with worse outcome. Accurate quantification of BPV requires frequent measurement, which is not practical with conventional sphygmomanometry. Finger photo-plethysmography allows non-invasive continuous blood pressure measurement and has been validated against invasive measurement techniques. Hypothesis: Ultra-short-term BPV (uBPV) will be higher in patients with recent ischemic stroke compared to controls. Methods: We measured uBPV in 10 patients: 5 with stroke in the last 14 days (mean=6 days) and 5 healthy controls. Blood pressure was recorded with an ADInstruments NIBP System (Figure 1) for 15 minutes with 200 measurements/second. For each patient, the 15 minutes was divided into 10 epochs of 90 seconds. uBPV was calculated for each epoch and we used a linear mixed-effects model to account for repeated and clustered observations. Results: There was a mean±SD of 172,265±11,354 measurements per patient and 17,226±2,274 measurements per epoch. All measures of systolic uBPV were significantly higher in the stroke patients compared to controls (Table 1). The identical analyses were performed for diastolic and mean arterial blood pressure without significant results. Conclusion: This study demonstrates the feasibility of measuring BPV in stroke patients with finger photo-plethysmography, which was well tolerated and showed the expected increase in systolic BPV after stroke. Our data also introduce the concept of uBPV as a measure of BPV after stroke, which warrants additional study and correlation with clinical and radiographic outcomes.