Clinical Value of Digital Radiographic Coronary Quantification: Comparison with Visual Assessment and Coronary Flow Reserve

The value of quantitative assessment of coronary artery dimensions at the site of the most critical coronary stenosis was assessed by comparison with the correspondent reactive hyperaemia as measured by digital subtraction angiography and with the functional results. Thirty-two coronary lesions were analysed and flow reserve data were obtained in an additional 11 vascular distributions without coronary obstruction in 19 patients. Minimal diameter less than 1.25 mm and minimal area less than 1.5 mm2 at the site of the stenosis best separated vascular distributions with inadequate hyperaemic response from those with sufficient reactive hyperaemia (chi 2 = 19.57; P less than 0.0001). Identification of lesion severity based on videodensitometric percentage area stenosis greater than 70% or percentage diameter stenosis greater than 50% yielded similar but poorer results (respectively chi 2 = 14.53; P less than 0.001 and chi 2 = 10.29; P less than 0.005). Additionally, when visually determined percentage stenosis was compared to the quantitatively assessed value, only a fair correlation was observed (r = 0.74), with visual overestimation of lesion severity by an average of 11.1 +/- 9.8% (mean +/- SD). Reactive hyperaemia in vessels with coronary obstruction could be described from minimal coronary dimensions by a quadratic equation but did not correlate closely in this patient population (r = 0.54 with minimal diameter and r = 0.58 with minimal area).(ABSTRACT TRUNCATED AT 250 WORDS)