Age and sex distribution of beat-to-beat blood pressure variability after transient ischemic attack and minor stroke: A population-based study

Abstract

Background Beat-to-beat blood pressure variability is associated with increased stroke risk but its importance at different ages is unclear. Aims To determine the age-sex distribution of blood pressure variability in patients with transient ischemic stroke or minor stroke. Methods In consecutive patients within six weeks of transient ischemic stroke or non-disabling stroke (Oxford Vascular Study), non-invasive blood pressure was measured beat-to-beat over five minutes (Finometer). The age-sex distribution of blood pressure variability (residual coefficient of variation) was determined for systolic blood pressure and diastolic blood pressure. The risk of top-decile blood pressure variability was estimated (logistic regression), unadjusted, and adjusted for age, sex, and cardiovascular risk factors. Results In 908 of 1013 patients, excluding 54 in atrial fibrillation and 51 with low quality recordings, residual coefficient of variation was positively skewed with a median systolic residual coefficient of variation of 4.2% (IQR 3.2–5.5) and diastolic residual coefficient of variation of 3.9% (3.0–5.5), with 90th centile thresholds of 7.2 and 7.3%. Median systolic residual coefficient of variation was higher in patients under 50 years (4.5 and 3.0–5.3) compared to 60–70 years (4.1 and 3.2–5.2), but rose to 4.5% (3.5–6.9) above 80 years, with an increasingly positive skew. The proportion of patients with markedly elevated blood pressure variability in the top-decile increased significantly per decade (OR 1.72, p < 0.001), after adjustment for sex and risk factors. Conclusions Median beat-to-beat blood pressure variability fell in midlife, reflecting loss of physiological, organized blood pressure variability. However, rates of markedly elevated blood pressure variability significantly increased with greater age, suggesting that blood pressure variability may be particularly important in older patients.

Aortic Stiffness, Pulse Pressure, and Cerebral Pulsatility Progress Despite Best Medical Management: The OXVASC Cohort

“…Furthermore, there were similar distributions of aortic stiffness, aortic pulse pressure and cerebral arterial pulsatility by age and sex, and the cross-sectional relationship between aortic pulse pressure and cerebral arterial pulsatility was partially mediated by arterial stiffness. 19 This longitudinal follow-up study confirms the strong concurrent association between aortic pulse pressure, aortic stiffness and cerebral arterial pulsatility, and further demonstrates that aortic blood pressure level predicts a greater increase in the rate of progression of aortic stiffness and pulsatility. As such, although an acute reduction in aortic pulse pressure may reduce cerebral arterial pulsatility directly, control of mid-life elevated aortic blood pressure, and diastolic blood pressure in particular, may reduce progression of arterial stiffness and aortic pulse pressure and therefore future cerebral small vessel disease and its sequelae.…”

Blood Pressure Complexity Discriminates Pathological Beat‐to‐Beat Variability as a Marker of Vascular Aging

“…The OXVASC population consists of >92 000 individuals registered with about 100 primary care physicians in Oxfordshire, UK. 7 , 34 , 35 , 36 …”

“…), and patients were followed up face‐to‐face for up to 10 years. 7 , 34 , 35 , 36 Consenting patients underwent a physiological assessment at the 1‐month follow‐up visit. Participants were excluded from this analysis if they were aged <18 years, cognitively impaired (Mini‐Mental State Examination score, <23), or pregnant; had atrial fibrillation, active cancer, autonomic failure, a recent myocardial infarction, unstable angina, heart failure (New York Heart Association 3–4 or ejection fraction <40%), or untreated bilateral carotid stenosis (>70%).…”

“…Continuous 3‐lead ECG and noninvasive finger arterial BP (Finometer MIDI; Finapres Medical Systems, the Netherlands) were measured over at least 5 minutes, and up to 10 minutes, at 200 Hz during supine conditions via a Powerlab 8/35 (ADInstruments) software, preferentially measured from the middle phalanx of the middle finger of the nondominant arm when possible. 5 , 7 , 35 , 36 …”

“…Uncontrolled high blood pressure (BP) increases the risk of stroke and all cardiovascular events, 1 whereas visit‐to‐visit, 2 , 3 day‐to‐day, 4 and beat‐to‐beat 5 BP variability (BPV) predict the risk of recurrent stroke, all cardiovascular events, cognitive impairment, 6 and death. However, short‐term, beat‐to‐beat BPV, estimated by conventional statistical estimates (eg, SD and coefficient of variations [CV]), shows a U‐shaped relationship with age, 7 likely reflecting higher BPV attributable to intact autonomically driven fluctuation of BPV in younger people but also reflecting failure of compensatory mechanisms 8 , 9 caused by aging and hypertension. The prognostic value of short‐term, beat‐to‐beat BPV is therefore likely to represent both impaired autonomic function, as seen after acute ischemic stroke, 10 intracerebral hemorrhage, 11 and subarachnoid hemorrhage, 12 as well as vascular aging (arterial stiffness and pulse pressure [PP]).…”