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Vasoconstriction of normal coronary arteries has been reported after intracoronary (i.c.) administration of acetylcholine (Ach) in cardiac transplant patients and has been related to early endothelial disfunction; the clinical correlates of this response are still unknown.We infused graded i.c. concentrations of Ach in 32 pts with angiographically smooth coronary arteries 1 to 3 years after heart transplantation. Changes in diameters of the proximal and middle segments of the left anterior descending coronary artery were measured by quantitative coronary angiography (automatic edge detection).The response to Ach ranged from +44% to -58%; at linear regression analysis it was significantly related to the plasma levels of cyclosporine (r = -0.39, p.05) and triglycerides (r = -0.42, p.02) but not to vessel diameter, recipient and donor age, time after transplantation, hypertension, cholesterol levels, number of acute rejection episodes and previous cytomegalovirus infections.In heart transplant pts with angiographically normal coronary arteries i.c. Ach may reveal endothelial disfunction which is associated with high cyclosporine and triglycerides plasma levels. Whether this response may predict an earlier development of coronary disease remains to be elucidated.

Although restenosis after percutaneous transluminal coronary angioplasty (PTCA) may have morphologic characteristics which are not similar to the original stenosis, it is unknown if a different morphology is also associated with a different clinical presentation. Eleven consecutive patients with angina and single vessel disease had a recurrence of symptoms and restenosis within 6 months of successful PTCA. Seven patients (group I) complained of spontaneous angina before PTCA and had a positive hyperventilation test, while 4 patients complained of exercise-induced angina and had a negative hyperventilation test (group II). In group I restenosis was associated with the same clinical presentation as before PTCA and the hyperventilation test was positive in 6 patients. The angiographic morphology of restenosis was changed in 4 patients. In group II restenosis occurred with the same clinical presentation as before PTCA, the hyperventilation test was negative in 3 patients while the angiographic morphology of restenosis was unchanged in only 1 patient. Although morphology of restenosis is different from the original stenosis, clinical presentation associated with restenosis is generally the same as before PTCA. The response to vasoactive stimuli is independent from the morphology of the lesion.

Aim of this study was to evaluate the factors affecting the duration of the recovery time (RT) after a positive exercise stress test and to define its relationship with the extent of coronary artery disease (CAD).We studied 109 consecutive patients with a positive exercise test and proven coronary disease.RT was neither related to the severity of CAD, nor to exercise duration, rate-pressure product at the end of the exercise and maximum ST segment depression. A significant linear relationship was found between RT and the time of ischemia during exercise (IT) (r = 0.66, p.001). This relationship was analyzed separately in patients (pts) with advanced (Group I) and in pts with less severe CAD (Group II). The regression line of the data showed a similar slope but a higher y-axis intercept in Group I than in Group II (p.05). The RT/IT ratio was in fact significantly higher in Group I than in Group II (3.0 +/- 1.3 vs 1.7 +/- 0.7, p.0001). Discriminant analysis was performed to predict the presence of advanced CAD: using the RT/IT ratio instead of RT correct classification rate of the model increased from 81.4 to 86.7%, predictive accuracy from 73.7 to 85.3% and true negative rate from 85.3 to 87.4%.These results suggest that the normalization of the recovery time by time of ischemia during the test provides a simple and useful index for the prediction of the extent of coronary artery disease.