The clinical significance of myocordial perfusion defects present early after angiographically successful percutaneous transluminal coronary angioplasty was assessed in 53 patients using thalllum-201 single photon emission computed tomography combined with pharmacologic vesodilation induced by a large dose (300 mg) of orally administered dipyridamole. Myocardial tomographic images were obtained at a mean of 20 ± 6 h (SD) before and 2.9± 2.7 days after angioplasty. Before angioplasty, 15 (28%) of the 53 patients developed angina after dipyridamole administration, in contrast to only 3 (7.5%) of 40 patients after angioplasty (p < 0.001). The mean percent luminal area stenosis decreased from 93 ± 6% before angioplasty to 34 ± 17% after angioplasty (p < 0.001). Myocardial perfusion defects, present in 49 (93%) of the 53 patients before angioplasty, were reversible in 44 patients (83%), all of whom underwent dilation of arteries supplying the ischemic areas. After angioplasty, 26 (65%) of 40 patients had no ischemic defects, whereas 14 (35%) of the patients still had an ischemic defect in the vascular territory of the dilated artery. After a menn follow-up period of 21.7 months, 13 (33%) of 39 patients developed reslenosis, 10 of whom had an ischemic defect early after angioplasty. Restenosis developed in 10 (71%) of 14 patients with an ischemic defect after angioplasty. but in only 3 (11.5%) of the patients without an ischemic defect (p = 0.007). In conclusion, thallium-201 tomography after oral dipyridamole affords convenient assessment of the physiologic significance of coronary stenosis present before angloplasty and the residuel stenosis after angioplasty. Patients with a dipyridamole-induced perfusion defect before hospital discharge are at high risk for coronary restenosis.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine