Blood Pressure Complexity Discriminates Pathological Beat-to-Beat Variability as a Marker of Vascular Aging. Journal of the American Heart Association Background Beat-to-beat blood pressure variability (BPV) is associated with an increased risk of stroke but can be driven by both healthy physiological processes and failure of compensatory mechanisms. Blood pressure (BP) complexity measures structured, organized variations in BP, as opposed to random fluctuations, and its reduction may therefore identify pathological beat-to-beat BPV. Methods and Results In the prospective, population-based OXVASC (Oxford Vascular Study) Phenotyped Cohort with transient ischemic attack or minor stroke, patients underwent at least 5 minutes of noninvasive beat-to-beat monitoring of BP (Finometer) and ECG to derive the following: BPV (coefficient of variation) and complexity (modified multiscale entropy) of systolic BP and diastolic BP, heart rate variability (SD of R-R intervals), and baroreflex sensitivity (BRS; Welch's method), in low- (0.04-0.15 Hz) and high-frequency (0.15-0.4 Hz) bands. Associations between BPV or BP complexity with autonomic indexes and arterial stiffness were determined (linear regression), unadjusted, and adjusted for age, sex, and cardiovascular risk factors. In 908 consecutive, consenting patients, BP complexity was inversely correlated with BPV coefficient of variation (<0.001) and was similarly reduced in patients with hypertension or diabetes (<0.001). However, although BPV coefficient of variation had a U-shaped relationship with age, BP complexity fell systematically across age quintiles (quintile 1: 15.1 [14.0-16.1] versus quintile 5: 13.8 [12.4-15.1]) and was correlated with markers of autonomic dysfunction (heart rate variability SD of R-R intervals:  = 0.20; BRS low frequency: 0.19; BRS high frequency: 0.26) and arterial stiffness (pulse wave velocity: -0.21; all <0.001), even after adjustment for clinical variables (heart rate variability SD of R-R intervals: 0.12; BRS low frequency and BRS high frequency: 0.13 and 0.17; and pulse wave velocity: -0.07; all <0.05). Conclusions Loss of BP complexity discriminates BPV because of pathological failure of compensatory mechanisms and may represent a less confounded and potentially modifiable risk factor for stroke. 10.1161/JAHA.121.022865

U-shaped relationship between hemoglobin level and severity of ischemic stroke. Naess Halvor,Logallo Nicola,Waje-Andreassen Ulrike,Thomassen Lars,Kvistad Christopher E Acta neurologica Scandinavica BACKGROUND AND AIM:We aimed to explore the relation between hemoglobin level and ischemic stroke severity and short-term improvement in patients admitted to hospital within 3 hours of stroke onset. METHODS:The relation between stroke severity and hemoglobin was explored by locally weighted scatterplot smoothing (lowess smoother) curves. The effect of hemoglobin on short-term outcome was determined by means of linear regression analyses with NIHSS score day 7 as dependent variable after adjusting for confounders including NIHSS score on admission. Analyses were performed to disclose clinical factor associated with hemoglobin level. RESULTS:This study includes 905 ischemic stroke patients admitted within 3 hours of stroke onset. Lowess smoother curves showed a U-shaped relation between NIHSS score on admission and mRS score day 7 and hemoglobin level. Regression analysis showed low hemoglobin to be independently associated with females, high age, severe stroke, low systolic blood pressure, prior cerebral infarction, not smoking, not atrial fibrillation, and unknown etiology (all P < 0.05). Another regression analysis showed that high NIHSS score day 7 was independently associated with low hemoglobin after adjusting for confounders including NIHSS score on admission. CONCLUSIONS:We found a U-shaped relationship between hemoglobin level on admission and stroke severity. There was no U-shaped relationship between improvement and hemoglobin level. Poor short-term improvement was associated with low hemoglobin levels. 10.1111/ane.13100