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Background There are limited data regarding the immediate and long-term effect of balloon angioplasty on the coronary flow reserve evaluated in a multicentre setting.Methods and Results A total of 86 patients with one-vessel disease and normal left ventricular function were analysed before and after optimal balloon angioplasty (diameter stenosis <35%) and at 6-month follow-up. Coronary flow reserve was assessed with a Doppler guide wire. A low coronary flow reserve (≤2·5) after PTCA, due to an increased baseline blood flow velocity, was encountered in 42 of the 86 patients (49%). Recurrence of angina and target lesion revascularization were more frequent in these patients than in patients with a coronary flow reserve >2·5 (46% vs 23% and 36% vs 16%, respectively;P<0·05) due to a trend towards restenosis (29% vs 16%;P=0·15) or a low coronary flow reserve at follow-up due to persistent elevated baseline blood flow velocity. Patients without restenosis showed a decrease or increase of coronary flow reserve during follow-up, determined by alterations of hyperaemic blood flow velocity.Conclusions Patients with an impaired coronary flow reserve directly after optimal balloon angioplasty showed a higher target lesion revascularization rate compared to patients with a coronary flow reserve >2·5. This patient group consists of patients prone to develop restenosis, while other patients are characterized by a persistently low coronary flow reserve, probably secondary to disturbed autoregulation and/or diffuse mild coronary atherosclerosis. Coronary flow reserve alterations in patients without restenosis were related to changes in hyperaemic blood flow velocity, suggesting that this phenomenon relates to epicardial remodelling. [ABSTRACT FROM PUBLISHER]

Aims Evaluation of angiographical and intracoronary Doppler-derived parameters of coronary stenosis severity.Methods and Results A total of 225 patients with one-vessel disease were studied before PTCA and at 6 months follow-up. Exercise electrocardiography was performed to document presence (n=157) or absence (n=138) of an ST segment shift (≥0·1mV). Intracoronary blood flow velocity analysis was performed to determine the proximal/distal flow velocity ratio, the distal diastolic/systolic flow velocity ratio and coronary flow velocity reserve. Receiver operator characteristic curves were calculated to assess the predictive value of these variables compared with the exercise test. The distal coronary flow velocity reserve demonstrated the best linear correlation for both percentage diameter stenosis and minimum lumen diameter (r=0·67 and r=0·66;P<0·01), compared to the diastolic/systolic flow velocity ratio (r=0·19 and r=0·14;P<0·01) and the proximal/distal flow velocity ratio (r=0·03 and r=0·07; not significant). The areas under the curve were 0·84±0·02; 0·82±0·03 and 0·83±0·03 for diameter stenosis, minimum lumen diameter and coronary flow velocity reserve, respectively. Logistic 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 intracoronary Doppler parameter for evaluation of coronary narrowings. Angiographical estimates of coronary lesion severity and distal coronary flow velocity reserve 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. [ABSTRACT FROM PUBLISHER]

The effects of an intracoronary infusion of nicardipine (0.2 mg over 10 min) on myocardial substrate uptake and function were studied in 16 patients with coronary artery disease and angina pecloris. Silent ischaemia, demonstrated by myocardial lactate production, was induced twice by pacing below anginal threshold. Nicardipine or saline was randomly infused during the first or second pacing. During pacing with nicardipine, no systemic effect was noted but coronary sinus flow increased (+ 18%; P<0.015) and myocardial oxygen uptake decreased by 12% (P<0.025). Transcardiac lactate production did not improve (– 8 to – 10 μmol min−1; NS) but net lactate uptake, estimated from radiolabelled lactate uptake, tended to rise and the glutamine uptake increased from 1.8 to 5.5 μmol min−1 (P<0.04). During recovery after pacing, lactate production decreased faster and LV peak (+) dP/dt and relaxation rate were significantly better after nicardipine infusion than after saline. Thus, during silent ischaemia induced by an increased oxygen demand, intracoronary nicardipine did not prevent lactate release but allowed a faster metabolic and functional recovery. These beneficial effects of nicardipine could be explained by an improved myocardial perfusion or by an effect on intracelluiar calcium homeostasis. [ABSTRACT FROM PUBLISHER]