Comparison by quantitative angiographic assessment of coronary stenoses of one view showing the severest narrowing to two orthogonal views.

Quantitative coronary arteriographic measurements were compared in 2 orthogonal views with the view that clearly showed the stenosis at its most severe in 147 lesions from 147 patients before, immediately after and 6 months after PTCA. In 21 of 147 patients (14%), 2 views could not be measured for technical reasons, even though all angiographers had tried to film 2 views. Lesion severity was slightly worse for 1 compared with 2 views (3.3 +/- 3.3% before PTCA, 3.6 +/- 3.8% after PTCA and 3.1 +/- 3.8% at follow-up). Similarly, minimal diameter was less for 1 view (0.11 +/- 0.09 mm before PTCA, 0.15 +/- 0.12 mm after PTCA and 0.13 +/- 0.09 mm at 6 months). When this systematic difference was taken into account, the 2 methods were within +/- 0.1 mm for minimal diameter in 288 of 376 measurements (77%) and within +/- 0.2 mm in 96%. For percent diameter stenosis the 2 methods were within +/- 5% in 90% and within +/- 10% in all but 2.7% (10 of 376). Thus, for routine clinical assessment, measurement of 1 view is adequate; for research purposes orthogonal views may sometimes be required.