NT-proBNP as a surrogate for unknown heart failure and its predictive power for peripheral artery disease outcome and phenotype.

Patients with peripheral artery disease (PAD) are at high risk of excess mortality despite major improvements in multimodal pharmacotherapy for cardiovascular disease. However, little is known about co-prevalences and implications for the combination of heart failure (HF) and PAD. Thus, NT-proBNP as a suggested surrogate for HF was evaluated in symptomatic PAD regarding long-term mortality. After approval by the institutional ethics committee a total of 1028 patients with PAD, both with intermittent claudication or critical limb ischemia were included after admission for endovascular repair and were followed up for a median of 4.6 years. Survival information was obtained from central death database queries. During the observation period a total of 336 patients died (calculated annual death rate of 7.1%). NT-proBNP (per one standard deviation increase) was highly associated with outcome in the general cohort in crude (HR 1.86, 95%CI 1.73-2.01) and multivariable-adjusted Cox-regression analyses with all-cause mortality (HR 1.71, 95%CI 1.56-1.89) and CV mortality (HR 1.86, 95% CI 1.55-2.15). Similar HR's were found in patients with previously documented HF (HR 1.90, 95% CI 1.54-2.38) and without (HR 1.88, 95%CI 1.72-2.05). NT-proBNP levels were independently associated with below-the-knee lesions or multisite target lesions (OR 1.14, 95% CI 1.01-1.30). Our data indicate that increasing NT-proBNP levels are independently associated with long-term mortality in symptomatic PAD patients irrespective of a previously documented HF diagnosis. HF might thus be highly underreported in PAD, especially in patients with the need for below-the-knee revascularization.

Lipoprotein (a) and long-term outcome in patients with peripheral artery disease undergoing revascularization.

BACKGROUND AND AIMS: Despite low LDL-C goals, the residual risk for further cardiovascular (CV) events in patients with peripheral artery disease (PAD) remains high. Lipoprotein (a) (Lp(a)) is a known risk factor for PAD incidence, but little is known regarding the outcome in patients with symptomatic PAD. Thus, this study investigates Lp(a) and CV mortality in PAD after endovascular repair. METHODS: A total of 1222 patients with PAD in two cohorts according to Lp(a) assay in nmol/L (n = 964, Lip-LEAD-A) or mg/dl (n = 258, Lip-LEAD-B) were followed up for 4.3 (IQR 3.0-5.6) or 7.6 (IQR 3.2-8.1) years. Lp(a) was measured before endovascular repair for either intermittent claudication (IC) or critical limb ischemia (CLI). Outcome information was obtained from the federal death registry. RESULTS: In Lip-LEAD-A, 141 CV-deaths occurred (annual calculated CV-death rate 3.4%), whereas 64 CV-deaths were registered in Lip-LEAD-B (annual calculated CV-death rate 3.3%). After adjustment for traditional CV risk factors Lp(a) was neither associated with outcome in Lip-LEAD-A (highest tertile HR 1.47, 95%CI [0.96-2.24]) nor in Lip-LEAD-B (highest tertile HR 1.34 [0.70-2.58]). Subanalyses for IC (HR 1.37 [0.74-2.55]; HR 1.10 [0.44-2.80], CLI (HR 1.55 [0.86-2.80], HR 3.01 [0.99-9.10]), or concomitant coronary artery disease (CAD; HR 1.34 [0.71-2.54]; HR 1.21 [0.46-3.17]) failed to show a significant association between Lp(a) and CV-mortality. CONCLUSIONS: In this large-scale cohort of symptomatic PAD no association of elevated Lp(a) with CV mortality was found over a median observation period of 5 years. Thus, an even longer study including asymptomatic patients is warranted.