Predictive Value of Reactive Hyperemia for Cardiovascular Events in Patients With Peripheral Arterial Disease Undergoing Vascular Surgery

• DOI: 10.1161/atvbaha.107.147322
• Publication Date: 2007-08-24T01:40:15Z
• Authors: Alex L. Huang; Annemarie E. Silver; Elena Shvenke; David W. Schopfer; Eiman Jahangir; Megan A. Titas; Alex Shpilman; James O. Menzoian; Michael T. Watkins; Joseph D. Raffetto; Gary Gibbons; Jonathan Woodson; Palma M. Shaw; Mandeep Dhadly; Robert T. Eberhardt; John F. Keaney; Noyan Gokce; Joseph A. Vita
• Keywords: Male; Brachial Artery; Hyperemia; Kaplan-Meier Estimate; Reactive hyperemia; 03 medical and health sciences; 0302 clinical medicine; Predictive Value of Tests; Odds Ratio; Humans; Endothelium; Prospective Studies; Aged; Proportional Hazards Models; Peripheral Vascular Diseases; Surrogate markers; Microcirculation; Age Factors; Middle Aged; Cardiovascular risk; Prognosis; 3. Good health; Flow-mediated dilation; Cardiovascular Diseases; Regional Blood Flow; Female; Blood Flow Velocity; Follow-Up Studies

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.