ABI and stroke: action at a distance and a call to action

The ankle-brachial index and risk of incident stroke in Chinese hypertensive population without atrial fibrillation: A cross-sectional study

We aimed to evaluate the relation of the ankle–brachial index (ABI) with the prevalence of stroke and to examine any possible effect modifiers among hypertensive patients without atrial fibrillation. A total of 10 750 subjects with hypertension aged 27‐96 years were included in the current study. The outcome was a stroke. Odds ratios of stroke concerning ABI were calculated using multivariate logistic regression models. Among 10 750 hypertensive participants, 690 (6.42%) had a stroke. Multivariate logistic analyses showed that ABI was negatively correlated with the prevalence of stroke (per SD increment; adjusted OR, 0.88; 95% CI, 0.82‐0.94). Compared with participants in Q 1, the odds ratios (95% CI) for those in the Q2 (1.05 to 1.10), Q3 (1.10 to 1.15), and Q4 (≥1.15) were 0.71 (0.56, 0.90), 0.87 (0.70, 1.08), and 0.81 (0.65, 1.01), respectively. However, compared with higher ABI value, lower ABI value (<1.05) would significantly increase the odds of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old. A generalized additive model and a smooth curve fitting showed that there existed an L‐shaped association between ABI and the prevalence of stroke. Our results suggest that an L‐shaped association between ABI and the prevalence of stroke was found in general hypertensive patients, with a turning point at about 1.05. Compared with higher ABI value, lower ABI value (<1.05) would significantly increase the prevalence of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old.

Prognostic implications of the Ankle Brachial Index in patients with acute ischemic stroke: A meta-analysis

BACKGROUND

The ankle brachial index (ABI) is recognized as a marker of atherosclerotic disease. The detection of ABI may improve the risk stratification.

METHODS

We systematically searched Pubmed and Embase (from the earliest date to October 2015) for studies evaluating the prognostic value of ABI in patients with acute ischemic stroke. Stroke or cardiovascular events, mortality and functional outcomes were analyzed.

RESULTS

Seventeen studies, containing 9404 patients, were included. The mean age of participants in each study ranged from 64 to 79 years. The prevalence of low ABI varied from 7.4% to 40.5%. In this quantitative analysis, we found that low ABI increased the risk of composite outcomes (myocardial infarction or stroke or mortality), disability and mortality.

CONCLUSION

The detection of ABI may help to identify high-risk patients for secondary stroke prevention.

The Association of Four-Limb Blood Pressure with History of Stroke in Chinese Adults: A Cross-Sectional Study

OBJECTIVE

We investigated the association of ankle-brachial blood pressure index (ABI), interarm blood pressure (BP) difference and interankle BP difference, obtained by simultaneous four-limb BP measurement, with history of stroke in a Chinese adult population.

METHODS

This cross-sectional study included 1485 participants aged ≥35 years in the framework of the China Hypertension Survey. We performed simultaneous four-limb BP measurement using oscillometric devices with the participants in the supine position and calculated ABI and interarm/interankle BP differences between the 4 limbs. Logistic regression analysis was used to estimate the association of these BP parameters and other factors with a history of stroke.

RESULTS

In univariate analyses, participants with ABI <0.9, interarm BP difference ≥15 mmHg, and interankle BP difference ≥10 mmHg had a higher prevalence of stroke than those without (p < 0.0001, p = 0.0152, p = 0.002, respectively). Multiple logistic regression analyses suggested, ABI <0.9 was independently associated with a history of stroke after adjustment for interarm BP difference ≥15 mmHg, interankle BP difference ≥10 mmHg, and traditional risk factors for stroke (p = 0.001). An interankle BP difference ≥10 mmHg was associated with prior stroke after the two variables of hypertension and ABI were removed from the logistic regression model (p = 0.0142). Net reclassification improvement analysis showed that inclusion of interankle BP difference ≥10 mmHg to the independent risk factors (age, family history of stroke, hypertension, and ABI) improved net reclassification by 11.92%.

CONCLUSION

ABI <0.9 is an independent risk factor for stroke prevalence in Chinese adults and it just detected a small propotion of paticipants. The addition of interankle BP difference ≥10 mmHg to the independent risk factors for stroke may improve the prediction of stroke.