Aortic stiffness improves the prediction of both diagnosis and severity of coronary artery disease

Elective coronography has low diagnostic yield for obstructive coronary artery disease (CAD). We aim to determine whether non-invasive aortic stiffness assessment improves diagnostic accuracy of CAD screening by reducing the number of false-positive results from the cardiac stress test. A cross-sectional study was conducted from January 2013 to September 2014 in our medical center. Electrocardiogram (ECG) stress test coupled with nuclear imaging was performed in 367 consecutive patients routinely followed for myocardial ischemia screening. Aortic pulse wave velocity (PWV) was assessed by applanation tonometry in the overall population. Forty-two patients underwent elective coronography because of ischemia. Theoretical PWV was calculated according to age, blood pressure and gender. The results were expressed as an index ((measured PWV-theoretical PWV)/theoretical PWV) for each patient. Ten patients presented with obstructive CAD, 16 patients had non-obstructive CAD and 16 patients had normal coronary angiography. PWV index and severity of CAD were positively correlated (P=0.001). All patients with obstructive CAD had a positive PWV index. When considering the PWV index retrospectively, the false positive results of cardiac stress test were significantly reduced (P<0.001). Twenty-three procedures may have been avoided in the present study cohort. The salient finding of this study was that in patients with known or suspected CAD, routinely followed aortic PWV index may be considered clinically useful for reducing the rate of unnecessary invasive angiographies. The clinical relevance of this individualized decision approach should be confirmed in a large-scale study. Prospective studies have the potential to evaluate the PWV index as a marker of CAD.