Relationships between ankle blood pressure indices and major adverse cardiovascular events in people with and without type 2 diabetes.

Background: The relationship between ankle blood pressure (BP) and cardiovascular disease remains unclear. We examined the relationships between known and new ankle BP indices and major cardiovascular outcomes in people with and without type 2 diabetes.

Methods: We used data from 3 large trials with measurements of ankle systolic BP (SBP), ankle-brachial index (ABI, ankle SBP divided by arm SBP), and ankle-pulse pressure difference (APPD, ankle SBP minus arm pulse pressure). The primary outcome was a composite of cardiovascular mortality, myocardial infarction, hospitalization for heart failure, or stroke. Secondary outcomes included death from cardiovascular causes, total (fatal and non-fatal) myocardial infarction, hospitalization for heart failure, and total stroke.

Results: Among 42,929 participants (age 65.6 years, females 31.3%, type 2 diabetes 50.1%, 53 countries), the primary outcome occurred in 7230 (16.8%) participants during 5 years of follow-up (19.4% in people with diabetes, 14.3% in those without diabetes). The incidence of the outcome increased with lower ankle BP indices. Compared with people whose ankle BP indices were in the highest fourth, multivariable-adjusted hazard ratios (HRs, 95% CI) of the outcome for each lower fourth were 1.05 (0.98-1.12), 1.17 (1.08-1.25), and 1.54 (1.54-1.65) for ankle SBP; HR 1.06 (0.99-1.14), 1.26 (1.17-1.35), and 1.48 (1.38-1.58) for ABI; and HR 1.02 (0.95-1.10), 1.15 (1.07-1.23), and 1.48 (1.38-1.58) for APPD. The largest effect size was noted for ankle SBP (HRs 1.05 [0.90-1.21], 1.21 [1.05-1.40], and 1.93 [1.68-2.22]), and APPD (HRs 1.08 [0.93-1.26], 1.30 [1.12-1.50], and 1.97 [1.72-2.25]) with respect to hospitalization for heart failure, while only a marginal association was observed for stroke. The relationships were similar in people with and without diabetes (all p for interaction > 0.05).

Conclusions: Inverse and independent associations were observed between ankle BP and cardiovascular events, similarly in people with and without type 2 diabetes. The largest associations were observed for heart failure and the smallest for stroke. Including ankle BP indices in routine clinical assessments may help to identify people at highest risk of cardiovascular outcomes.