title: Clinical significance of perfusion defects by thallium-201 single photon emission tomography following oral dipyridamole early after coronary angioplasty.
abstract: The clinical significance of myocardial perfusion defects present early after angiographically successful percutaneous transluminal coronary angioplasty was assessed in 53 patients using thallium-201 single photon emission computed tomography combined with pharmacologic vasodilation 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 less than 0.001). The mean percent luminal area stenosis decreased from 93 +/- 6% before angioplasty to 34 +/- 17% after angioplasty (p less than 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 mean follow-up period of 21.7 months, 13 (33%) of 39 patients developed restenosis, 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 angioplasty and the residual stenosis after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Baylor College of Medicine, Houston, Texas.
authors.forename: A
authors.initials: A
authors.lastname: Jain
authors.forename: J J
authors.initials: JJ
authors.lastname: Mahmarian
authors.forename: S
authors.initials: S
authors.lastname: Borges-Neto
authors.forename: D L
authors.initials: DL
authors.lastname: Johnston
authors.forename: W R
authors.initials: WR
authors.lastname: Cashion
authors.forename: J M
authors.initials: JM
authors.lastname: Lewis
authors.forename: A E
authors.initials: AE
authors.lastname: Raizner
authors.forename: M S
authors.initials: MS
authors.lastname: Verani
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000139:chemically induced; D000800:Angioplasty, Balloon; D003116:Color; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D004176:Dipyridamole / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D004361:Drug Tolerance; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013794:Thallium Radioisotopes / Q000008:administration & dosage; D013997:Time Factors; D014055:Tomography, Emission-Computed / Q000379:methods*; D014664:Vasodilation
chemical_list: D013794:Thallium Radioisotopes; D004176:Dipyridamole