Flow-mediated dilatation has an additive value to stress ECG for the diagnosis of angiographically significant coronary atherosclerosis

The objective of this study is to determine if flow-mediated endothelial-dependent vasodilatation (FMD) performed after stress electrocardiogram (ECG) test has an additive value for the diagnosis of significant coronary artery disease (CAD). We studied 322 patients who underwent stress ECG test, coronary arteriography (CAG), and FMD evaluation. The pretest probability (preTP) for the presence of significant CAD (≥50% stenosis) was 73%. The probability for the disease after positive or negative ECG test (postTP) was 75% and 62%, respectively. A positive FMD response after a positive stress test resulted in 86% postTP with prevalence of advanced CAD in this subgroup −70.4%. A negative FMD response after a positive treadmill test decreased the postTP to 50% (prevalence of significant CAD 25.5%) and could change clinical behavior – additional tests before proceeding to CAG. After negative stress test the postTP increased to 78% when FMD was positive (prevalence of the disease 50%), necessitating the performance of CAG. It decreased to 36% after a negative FMD (prevalence of the disease 11.5%), directing to conservative behavior. In a group with a high pretest probability for the presence of advanced coronary atherosclerosis, FMD has an additive value to stress ECG for the diagnosis of significant CAD and could guide clinical behavior.