Coronary pressure notch: An early non-hyperemic visual indicator of the physiologic significance of a coronary artery stenosis

The disappearance of a dichrotic notch on the peripheral arterial pulse wave has been associated with significant peripheral vascular disease. A similar observation has not been reported in the distal coronary pressure waveform. The purpose of this study was to investigate the significance of a coronary pressure notch distal to a coronary stenosis and its relationship to fractional flow reserve. Ninety-seven patients with 131 angiographically indeterminate lesions (40-80% diameter narrowing) underwent FFR measurements for physiological significance. Hemodynamic tracings were recorded prior to the administration of adenosine and visually analyzed for the presence or absence of a dicrotic notch in the distal coronary artery pressure tracing. The stenoses were then divided into two groups based on the presence or absence of a notch. Of the 54 lesions without a distal coronary pressure notch, 31 had a FFR ≥ 0.75 and of the 77 lesions with a notch, 75 had a FFR ≥ 0.76. The sensitivity and specificity of a pressure notch was 94% and 74%, respectively, with positive and negative predictive values of 57% and 97%, respectively. The presence of a distal coronary pressure notch was predictive of a FFR ≥ 0.76. The distal dicrotic pressure notch may be used as an additional parameter without requiring hyperemia for FFR measurements of uncertain clinical significance.