Statin use improves survival of patients with known or suspected lower extremity artery disease on all ankle brachial index levels.

Abstract

Background: Statin medication improves the prognosis of patients with lower extremity artery disease (LEAD). Research has previously focused on patients with a lowered ankle brachial index (ABI) excluding patients with a normal or elevated ankle brachial index. The aim of this study was to analyze the impact of statin use on survival and cardiovascular mortality in patients with LEAD of different severity depicted by the ABI level. Patients and methods: 4128 ABI measurements by trained and experienced nurses between 2000 and 2009 were combined with medication data from the Social Insurance Institution and causes of death data from the national causes of death registry. End of follow-up was set at the end of 2014. The data of statin use included all statin medication with the Anatomical Therapeutic Chemical (ATC) classification codes between C10AA01 and C10AA08. Results: 1956 (47.4%) patients had statin medication. Statin use was associated with improved overall survival and amputation free survival (AFS) on all ABI levels. When adjusted for age, sex and diabetes the greatest overall survival benefit from statin use was for the patients with ABI>1.3 (hazard ratio, HR: 0.67, 95% CI: 0.48-0.94, p=0.020, reference group statin non-users) and ABI 0.9-1.3 (HR: 0.78, 95% CI: 0.65-0.94, p=0.008). In propensity score matched pairs statin treatment was associated with significantly lower all-cause mortality (p<0.0001), cardiovascular mortality (p=0.034), cerebrovascular mortality (p=0.003) and embolic stroke related mortality (p=0.001) in patients with ABI >1.3 or <0.9. Overall survival benefit was significant in females with ABI<0.5 and in males across several ABI levels. Conclusions: According to our study, statins seem to improve overall and amputation free survival regardless of ABI level. Statin use was associated with lower mortality from cerebrovascular disease, overall mortality and in the propensity score matched patients with ABI<0.9 or >1.3 with cardiovascular mortality.