Background and Purpose: The ankle-brachial index (ABI) is a fast, cheap, non-invasive indicator of atherosclerotic burden that may also be indicative of stroke recurrence. In this systematic review and meta-analysis, we sought to explore ABI’s merit as a marker for stroke recurrence and vascular risk by synthesizing the data currently available in the stroke literature.
Methods: We searched Embase, MEDLINE, and Pubmed databases for prospective cohort studies that included consecutive stroke and/or transient ischemic attack (TIA) patients, measured ABI at baseline, and performed a follow-up assessment at least 12 months following initial stroke/TIA. The following endpoints were chosen for our analysis: (1) recurrent stroke and (2) combined vascular endpoint (recurrent vascular event or vascular death). Crude risk ratios and adjusted Cox proportional hazard ratios (HRs) were combined separately using the random-effects model. Study level characteristics (e.g. percent of cohort with a history of hypertension, average cohort age, and mean follow-up duration) were included as meta-regression covariates.
Results: We included 11 studies (5374 patients). Low ABI was associated with an increased risk of recurrent stroke (pooled estimated HR 1.70, 95% CI 1.10-2.64) and vascular events or vascular death, following stroke (pooled estimated HR 2.22, 95% CI 1.67-2.97). No significant heterogeneity was observed in the meta-analysis.
Conclusion: Our results confirm the prognostic value of ABI for the recurrence of stroke. It is likely that the inclusion of ABI in risk calculation models will help in improving accuracy of existing models.