Metabolic syndrome and cardiovascular risk prediction in peripheral arterial disease.

BACKGROUND AND AIMS

Metabolic syndrome (MetS) was reported to be associated with increased cardiovascular risk in various settings, however its prognostic impact in peripheral arterial disease (PAD) is scanty.

METHODS AND RESULTS

We prospectively studied 173 patients with intermittent claudication and ankle/brachial index (ABI)<0.90, in whom MetS was defined using the criteria of both the revised version of the Adults Treatment Panel III (rATP III) and the International Diabetes Federation (IDF). Of these patients, 52.6% met the rATP III and 54.9% the IDF criteria for MetS. During a median follow-up of 31 months, 54 cardiovascular events occurred. Kaplan-Meier curves showed a greater incidence of ischemic events in patients with MetS than in those without. However, adjusted Cox analyses revealed that only IDF-MetS was independently associated with increased cardiovascular risk (HR=1.91, 95% CI 1.03-3.51, p=0.038). Kaplan-Meier curves for the four groups of patients delineated according to the bootstrapped ABI cut-off value (0.73) and the presence or absence of IDF-MetS revealed that the syndrome improved the predictive power of ABI alone. Actually, among patients with an ABI≤0.73, those with IDF-MetS had a higher cardiovascular risk than those without the syndrome (HR=2.55, 95% CI 1.22-5.12, p=0.012). This was confirmed by c-statistic, which was 0.56 for ABI alone and increased to 0.65 (p=0.046) when IDF-Mets was added to the pressure index.

CONCLUSION

In PAD, IDF-MetS, but not rATP III-MetS, is associated with an increased risk of cardiovascular events. Furthermore, IDF-MetS adds to the prognostic value of ABI, currently the most powerful prognostic indicator in PAD.