ABSTRACT
BACKGROUND: Although endothelial function is a marker for cardiovascular risk, endothelial dysfunction assessment is not routinely used in daily clinical practice. A growing challenge has emerged in identifying patients prone to cardiovascular events. We aim to investigate whether abnormal endothelial function may be associated with adverse 5-year outcomes in patients presenting to a chest pain unit (CPU). METHODS: Following endothelial function testing using EndoPAT 2000 in 300 consecutive patients without a history of coronary artery disease, patients underwent coronary computerized tomographic angiography (CCTA) or single-photon emission computed tomography according to availability. RESULTS: Mean 10-year Framingham risk score (FRS) was 6.6â±â5.9%; mean 10-year atherosclerotic cardiovascular disease (ASCVD) risk was 7.1â±â7.2%; median reactive hyperemia index (RHI) as a measure of an endothelial function 2.0 and mean was 2.0â±â0.4. During a 5-year follow-up, the 30 patients who developed major adverse cardiovascular events (MACE), including all-cause mortality, nonfatal myocardial infarction, hospitalization for heart failure or angina pectoris, stroke, coronary artery bypass grafting, and percutaneous coronary interventions, had higher 10-year FRS (9.6â±â7.8 vs. 6.3â±â5.6%; P â=â0.032), higher 10-year ASCVD risk (10.4â±â9.2 vs. 6.7â±â6.9%; P â=â0.042), lower baseline RHI (1.6â±â0.5 vs. 2.1â±â0.4; P â<â0.001) and a greater degree of coronary atherosclerotic lesions (53 vs. 3%, P â<â0.001) on CCTA compared with patients without MACE. Multivariate analysis demonstrated that RHI below the median was an independent predictor of 5-year MACE (odds ratio 5.567, 95% confidence interval 1.955-15.853; P â=â0.001). CONCLUSION: Our findings suggest that noninvasive endothelial function testing may contribute to clinical efficacy in triaging patients in the CPU and in predicting 5-year MACE. CLINICAL TRIALSGOV IDENTIFIER: NCT01618123.
