Long-term prognostic implications of visit-to-visit blood pressure variability in patients with ischemic stroke.
BACKGROUND
Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerotic diseases. High BPV has recently been shown to predict all-cause and cardiovascular mortality in patients with lacunar infarct. Whether BPV has prognostic implications in patients with ischemic stroke subtypes, other than those due to small-vessel occlusion, remains uncertain.


METHODS
We prospectively followed up the clinical outcome of 632 consecutive ischemic stroke patients without atrial fibrillation. The average BP and BPV, as determined by the coefficient of variation of the systolic and diastolic BP, were recorded during a mean 12 ± 6 outpatient clinic visits.


RESULTS
The average age of the population was 71 ± 11 years. After a mean of 76 ± 18 months of follow-up, 161 patients died (26%); 35% (n = 56 of 161) of these deaths were due to cardiovascular causes. Sixteen percent and 5% developed recurrent stroke and acute coronary syndrome (ACS), respectively. After adjusting for mean systolic BP and confounding variables, patients with high systolic BPV were at significantly greater risk of cardiovascular mortality (hazards ratio (HR) = 2.36; 95% confidence interval (CI) = 1.02-5.49; P < 0.05). High systolic BPV also predicted all-cause mortality after adjusting for mean systolic BP (HR = 1.79; 95% CI = 1.16-2.75; P < 0.05). There was no association between systolic BPV and nonfatal recurrent stroke or nonfatal ACS. Raised diastolic BPV did not predict recurrent nonfatal stroke, nonfatal ACS, or mortality.


CONCLUSIONS
Visit-to-visit systolic BPV predicts long-term all-cause and cardiovascular mortality in patients with ischemic stroke without atrial fibrillation, independent of other conventional risk factors, including average BP control.
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Kui-Kai
KK
Lau
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Yuen-Kwun
YK
Wong
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Kay-Cheong
KC
Teo
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Richard S K
RS
Chang
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Koon-Ho
KH
Chan
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Sonny F K
SF
Hon
Division of Cardiology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Ka-Lung
KL
Wat
Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Raymond T F
RT
Cheung
Division of Rehabilitation Medicine, Department of Medicine, University of Hong Kong, Hong Kong, China.
Leonard S W
LS
Li
Division of Cardiology, Department of Medicine, University of Hong Kong, Hong Kong, China;
Chung-Wah
CW
Siu
Division of Cardiology, Department of Medicine, University of Hong Kong, Hong Kong, China; hftse@hkucc.hku.hk.
Hung-Fat
HF
Tse
D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D002545:Brain Ischemia / Q000209:etiology / Q000401:mortality / Q000503:physiopathology*; D002423:Cause of Death / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D008297:Male; D009819:Office Visits; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
blood pressure; hypertension; ischemic stroke; prognosis; visit-to-visit blood pressure variability.