Accuracy of quantification of coronary arteriograms with hand-held calipers. A validation study.

This study compares the use of hand-held calipers to automated quantitative coronary arteriography in assessing coronary artery stenosis severity. 48 stenoses in the visually estimated range of 30-90% were evaluated in two orthogonal projections. Absolute stenosis dimensions and calculated transstenotic pressure gradient (PG) were compared. Hand-held calipers were of limited value in assessing absolute stenosis dimensions (SD = 0.32 mm, r = 0.80). However, the correlation found in the assessment of percent diameter stenosis (SD = 7.7%, r = 0.83) and PG (SD = 1.3 mm Hg, r = 0.83) was acceptable. In particular, the allocation into hemodynamically significant (n = 30) and nonsignificant (n = 18) stenoses, according to the criterion of a PG > 30 mm Hg, was accomplished identically by both methods.