Influence and interaction of diabetes and lipoprotein (a) serum levels on mortality of patients with peripheral artery disease.

BACKGROUND: Diabetes mellitus is a risk factor for early complications and mortality in patients with peripheral artery disease. Lipoprotein (a) [Lp(a)] is also suggested to be a marker of increased cardiovascular risk. We investigated the association and interaction between diabetes mellitus, lipoprotein(a) and mortality in high risk patients with peripheral artery disease (PAD). METHODS: We studied 700 consecutive patients [median age 73 years, interquartile range (IQR) 62-80, 393 male (56%)] with PAD from a registry database. Atherothrombotic risk factors (diabetes, smoking, hyperlipidaemia, arterial hypertension) and Lp(a) serum levels were recorded. We used stratified multivariate Cox proportional hazard analyses to assess the mortality risk at a given patient's age with respect to the presence of diabetes and Lp(a) serum levels (in tertiles). RESULTS: Patients with Lp(a) levels above 36 mg dL(-1) (highest tertile) and insulin-dependent type II diabetes had a 3.01-fold increased adjusted risk for death (95% confidence interval 1.28-6.64, P = 0.011) compared to patients without diabetes or patients with non-insulin-dependent type II diabetes. In patients with Lp(a) serum levels below 36 mg dL(-1) (lower and middle tertile), diabetes mellitus was not associated with an increased risk for death. CONCLUSION: Insulin-dependent type II diabetes mellitus seems to be associated with an increased risk for mortality in PAD patients with Lp(a) serum levels above 36 mg dL(-1). PAD patients with non-insulin-dependent type II diabetes, and patients with diabetes and Lp(a) levels below 36 mg dL(-1) showed survival rates comparable to PAD patients without diabetes.

Fibrinogen predicts mortality in high risk patients with peripheral artery disease.

OBJECTIVE: Fibrinogen plays a key role in the pathogenesis of atherosclerosis and complications of atherothrombotic disease. We investigated the prognostic impact of fibrinogen levels on mortality of high risk patients with peripheral artery disease (PAD). METHODS: We studied 486 patients with PAD and several cardiovascular comorbidities. Atherosclerotic risk factors and fibrinogen levels were determined at initial presentation and patients were followed for median 7 years (IQR 6-10) for all-cause and cardiovascular mortality. Multivariate Cox regression analysis was applied to assess the predictive value of fibrinogen levels (in quartiles) on patients' outcome. RESULTS: Cumulative survival rates at 1, 3, 5 and 10 years were 96, 91, 83 and 67%, respectively. Overall, 138 patients (28%) died, 70% of these patients died of cardiovascular complications (n=96). Patients with fibrinogen levels 10.2-12.2 micromol/l (third quartile) and patients with fibrinogen levels above 12.2 micromol/l (fourth quartile) had a significantly increased adjusted risk for all-cause mortality (hazard ratios [HR] 1.87 and 1.90, p=0.025 and p=0.020, respectively) compared to patients in the lowest quartile (fibrinogen below 8.6 micromol/l). A consistent effect was observed for cardiovascular causes of death. Diabetes mellitus and critical limb ischemia were the only other independent predictor variables (HR 2.08, p<0.001 and 1.88, p=0.001, respectively). CONCLUSION: Elevated fibrinogen levels in high risk patients with PAD indicate an increased risk for poor outcome, particularly for fatal cardiovascular complications.