Predictive value of noninvasively determined endothelial dysfunction for long-term cardiovascular events in patients with peripheral vascular disease.
OBJECTIVE
The goal of this study was to prospectively examine the long-term predictive value of brachial-artery endothelial dysfunction for future cardiovascular events.


BACKGROUND
Brachial-artery endothelial function is impaired in individuals with atherosclerosis and coronary risk factors. The prospective relation between endothelial function determined by brachial-artery ultrasound and long-term cardiovascular risk is unknown.


METHODS
We examined brachial-artery endothelial function using ultrasound in 199 patients with peripheral arterial disease before elective vascular surgery. Patients were prospectively followed with an average follow-up of 1.2 years after surgery.


RESULTS
Thirty-five patients had an event during follow-up, including cardiac death (5 patients), myocardial infarction (17 patients), unstable angina (10 patients), or stroke (3 patients). Preoperative endothelium-dependent flow-mediated dilation (FMD) was significantly lower in patients with an event (4.4 +/- 2.8%) compared with those without an event (7.0 +/- 4.9%, p < 0.001), whereas endothelium-independent vasodilation to nitroglycerin was similar in both groups. In a Cox proportional-hazards model, independent predictors of events included age (p = 0.003), more invasive surgery (surgery other than carotid endarterectomy, p = 0.02), and impaired brachial-artery endothelial function (p = 0.002). Risk was approximately nine-fold higher in patients with FMD <8.1% (lower two tertiles) compared with those in the upper tertile (odds ratio 9.5; 95% confidence interval 2.3 to 40).


CONCLUSIONS
Impaired brachial-artery endothelial function independently predicts long-term cardiovascular events in patients with peripheral arterial disease. The findings suggest that noninvasive assessment of endothelial function using brachial-artery FMD may serve as a surrogate end point for cardiovascular risk.
Gokce
Noyan
N
Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, USA.
Keaney
John F
JF
Hunter
Liza M
LM
Watkins
Michael T
MT
Nedeljkovic
Zoran S
ZS
Menzoian
James O
JO
Vita
Joseph A
JA
D000368:Aged; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000209:etiology / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016491:Peripheral Vascular Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D018617:Ultrasonography, Doppler, Pulsed; D014664:Vasodilation