Objective: To study the relationship between ankle-brachial index (ABI) and all cause mortality and cardiovascular disease mortality in men with several atherosclerotic risk factors.
Methods: 1941 male patients with no less than two atherosclerotic risk factors, aged 67 (36 approximately 96), from 20 hospitals in Shanghai and Beijing, underwent examination of ABI and were followed up for 13.6 +/- 1.3 months to record the all cause mortality and cardiovascular disease (CVD) mortality.
Results: The baseline examination showed that 467 patients were with the ABI <or= 0.9 and diagnosed as with peripheral arterial disease (PAD) and 1474 patients were found as with the normal ABI (between 0.91 and 1.40). The age of the PAD patients was 72 +/- 10 years, significantly older than that of those patients with normal ABI (66 +/- 12 years, P < 0.001). The rates of hypertension, diabetes mellitus, and smoking of the PAD patients were 77.0%, 46.3%, and 71.0% respectively, all significantly higher than those of the patients with normal ABI (68.5%, 32.5%, and 63.4% respectively, P < 0.01, P < 0.01. and P < 0.03). The all cause mortality and CVD mortality of the PAD patients were 15.4% and 5.1% respectively, both significantly higher than those of the patients with the ABI > 0.9 (7.7% and 1.8%, both P < 0.01). After adjusting other risk factors, the patients with 0.41 < ABI <or= 0.9 were more than 1.585 times likely to die than those with 1.0 < ABI <or= 1.4 (95% CI: 1.126 approximately 2.230). The patients with the ABI <or= 0.4 were more than 4.443 times likely to die of CVD than those with 1.0 < ABI <or= 1.4 (95% CI: 1.811 approximately 10.902). The RR for CVD death in the patients with 0.41 < ABI <or= 0.9 was 1.859 (95% CI: 1.091 approximately 3.166). The all cause survival rate and CVD survival rate of the PAD group were both significantly lower than those of the normal-ABI group (both P < 0.001).
Conclusion: Low ABI is an independent risk factor to all cause mortality and CVD mortality, especially to CVD mortality.