Lower reactive hyperemia (OR 2.7; 95% CI 1.2-5.9) and lower flow-mediated dilation (OR 4.2; 95% CI 1.8-9.8) independently predicted cardiovascular events in patients with peripheral arterial disease.
Cohort (n=267)
Does lower reactive hyperemia predict cardiovascular events in patients with peripheral arterial disease undergoing vascular surgery?
Lower reactive hyperemia and impaired flow-mediated dilation are independent predictors of increased cardiovascular risk in patients with peripheral arterial disease.
Effect estimate: OR 2.7 (95% CI 1.2 to 5.9)
p-value: p=0.018
OBJECTIVE: Reactive hyperemia is the compensatory increase in blood flow that occurs after a period of tissue ischemia, and this response is blunted in patients with cardiovascular risk factors. The predictive value of reactive hyperemia for cardiovascular events in patients with atherosclerosis and the relative importance of reactive hyperemia compared with other measures of vascular function have not been previously studied. METHODS AND RESULTS: We prospectively measured reactive hyperemia and brachial artery flow-mediated dilation by ultrasound in 267 patients with peripheral arterial disease referred for vascular surgery (age 66+/-11 years, 26% female). Median follow-up was 309 days (range 1 to 730 days). Fifty patients (19%) had an event, including cardiac death (15), myocardial infarction (18), unstable angina (8), congestive heart failure (6), and nonhemorrhagic stroke (3). Patients with an event were older and had lower hyperemic flow velocity (75+/-39 versus 95+/-50 cm/s, P=0.009). Patients with an event also had lower flow-mediated dilation (4.5+/-3.0 versus 6.9+/-4.6%, P<0.001), and when these 2 measures of vascular function were included in the same Cox proportional hazards model, lower hyperemic flow (OR 2.7, 95% CI 1.2 to 5.9, P=0.018) and lower flow-mediated dilation (OR 4.2, 95% CI: 1.8 to 9.8, P=0.001) both predicted cardiovascular events while adjusting for other risk factors. CONCLUSIONS: Thus, lower reactive hyperemia is associated with increased cardiovascular risk in patients with peripheral arterial disease. Furthermore, flow-mediated dilation and reactive hyperemia incrementally relate to cardiovascular risk, although impaired flow-mediated dilation was the stronger predictor in this population. These findings further support the clinical relevance of vascular function measured in the microvasculature and conduit arteries in the upper extremity.
Huang et al. (Fri,) conducted a cohort in Peripheral arterial disease (n=267). Reactive hyperemia and flow-mediated dilation was evaluated on Cardiovascular events (cardiac death, myocardial infarction, unstable angina, congestive heart failure, and nonhemorrhagic stroke) (OR 2.7, 95% CI 1.2 to 5.9, p=0.018). Lower reactive hyperemia (OR 2.7; 95% CI 1.2-5.9) and lower flow-mediated dilation (OR 4.2; 95% CI 1.8-9.8) independently predicted cardiovascular events in patients with peripheral arterial disease.