Physiologic assessment of coronary stenoses of intermediate severity can facilitate patient selection for coronary angioplasty

Abstract

Conventional angiographic assessment of coronary artery disease can over- or under-estimate the physiologic significance of individual coronary stenoses. To determine whether physiologic measurements of the significance of stenoses might more accurately guide the use of interventional procedures, we did not perform coronary angioplasty in 26 consecutive patients with 30 stenoses who were referred to angioplasty. In each patient, all focal lesions, while considered significant by visual assessment, were found to be physiologically insignificant as defined by a normal coronary flow reserve (more than 3.5:1 peak-to-resting velocity; n = 17) or a low translesional pressure gradient (less than 20 mm Hg; n = 25) or both. Sixteen patients were Canadian anginal class IV, 9 were class III, and 1 was class I. Computer-based quantitative angiography performed retrospectively showed a maximal percent diameter stenosis of 58 .+-. 9 (mean .+-. SD) and percent area stenosis of 78 .+-. 9. At late follow-up (22 .+-. 11 months), all but 1 patient reported less chest pain and 25 of 26 (96%) patients were classed in anginal class II or lower. There was no mortality or significant morbidity related to the undilated lesions. These data suggest that patients with coronary stenoses that appear important by angiography but are found to be physiologically insignificant have subsequent symptom improvement and an absence of clinical events without having undergone interventional treatments. Routine measurement of physiological parameters during cardiac catheterization may identify patients who are unlikely to benefit from interventional procedures.