Carotid Artery Reactivity Predicts Events in Peripheral Arterial Disease Patients.

OBJECTIVE

Patients with peripheral arterial disease (PAD) have increased risk on future cerebro- and cardiovascular events. Our aim was to examine whether carotid artery reactivity (CAR; a novel, simple procedure to examine endothelial function) predicts cardiovascular events in PAD patients.

BACKGROUND

Increased risk for future cardiovascular events in PAD patients is likely related to endothelial dysfunction, highlighting the necessity for simple assessment of endothelial function.

METHODS

A total of 172 PAD patients (68 ± 10 years, 67% male) underwent the CAR, which involves ultrasound measurement of carotid artery diameter during sympathetic stimulation produced by 90-second hand immersion in 4°C ice-water (ie, cold pressor test). CAR-responses were dichotomized into carotid constriction or dilation. We recorded cardiac and cerebrovascular events, mortality, and clinical progression to percutaneous transluminal angioplasty or loss of patency during 12-month follow-up.

RESULTS

Eighty-two PAD patients demonstrated carotid constriction and 90 patients demonstrated dilation. PAD patients with carotid constriction showed more cardiovascular events compared to patients with dilation (Kaplan-Meier Log rank; P < 0.05). Cox proportional hazard models showed that patients with carotid constriction continued to show higher risk for cardiovascular events [hazard ratio: 4.1; 95% confidence interval (CI), 1.3-12.5] and clinical progression (hazard ratio: 2.0; 95% CI, 1.2-3.3), even after adjustment for other risk factors. Ankle brachial pressure index and carotid intima-medial thickness alone did not predict (cardiovascular) event or improve risk assessment beyond that provided by CAR.

CONCLUSION

Carotid vasoconstriction identifies PAD patients with a 4-fold increased risk for future cardiovascular events and 2-fold increased risk for clinical deterioration. CAR provides a simple, novel strategy to predict cardiovascular events and progression in PAD patients.

CLINICAL TRIAL REGISTRATION

www.trialregister.nl/trialreg/index.asp, NTR-4117.