Angiographical and Doppler flow-derived parameters for assessment of coronary lesion severity and its relation to the result of exercise electrocardiography

Aims Evaluation of angiographical and intracoronary Doppler-derived paramet ers of coronary stenosis severity. Methods and Results A total of 225 patients with one-vessel disease were st udied before PTCA and at 6 months follow-up. Exercise electrocardiography w as performed to document presence (n=157) or absence (n=138) of an ST segme nt shift (greater than or equal to 0.1 mV). Intracoronary blood flow veloci ty analysis was performed to determine the proximal/distal flow velocity ra tio, the distal diastolic/systolic flow velocity ratio and coronary flow ve locity reserve. Receiver operator characteristic curves were calculated to assess the predictive value of these variables compared with the exercise t est. The distal coronary flow velocity reserve demonstrated the best linear correlation for both percentage diameter stenosis and minimum lumen diamet er (r=0.67 and r=0.66; P<0.01), compared to the diastolic/systolic flow vel ocity ratio (r=0.19 and r=0.14; P<0.01) and the proximal/distal flow veloci ty ratio (r=0.03 and r=0.07; not significant). The areas under the curve we re 0.84 +/- 0.02; 0.82 +/- 0.03 and 0.83 +/- 0.03 for diameter stenosis, mi nimum lumen diameter and coronary flow velocity reserve, respectively. Logi stic regression analysis revealed that the percentage diameter stenosis or minimum lumen diameter and coronary flow velocity reserve were independent predictors for the result of stress testing. Conclusions The distal coronary flow velocity reserve is the best intracoro nary Doppler parameter for evaluation of coronary narrowings. Angiographica l estimates of coronary lesion severity and distal coronary flow velocity r eserve are good and independent predictors for the assessment of functional severity of coronary stenosis, emphasizing the complementary role of these parameters for clinical decision making. (C) 2000 The European Society of Cardiology.