title: Improved detection of myocardial perfusion reversibility by rest-nitroglycerin Tc-99m-MIBI: comparison with TI-201 reinjection.
abstract: BACKGROUND
  The role of nitroglycerin (NTG) in Tc-99m-methoxyisobutil isonitrile (MIBI) studies to improve the assessment of myocardial viability in patients with coronary artery disease and its comparison with TI-201 reinjection has not yet been clarified. This study aimed to test whether sublingual administration of NTG could improve the capability of Tc-99m-MIBI to detect reversibility in exercise-induced perfusion defects and to compare it with the TI-201 stress-redistribution-reinjection protocol.
  
  
  RESULTS
  Thirty-eight patients (33 men, 5 women; mean age 49.3 +/- 8.2 years with previous myocardial infarction [mean evolution 7.1 +/- 3.9 months]) underwent exercise, redistribution, and reinjection TI-201 imaging, as well as exercise, rest, and NTG MIBI myocardial scintigraphy (3-day protocol). A total of 494 myocardial segments were assessed by quantitative analysis. Of the 136 myocardial segments with fixed defects on exercise-rest sestamibi imaging, 109 (80%) did not change after NTG MIBI study, and 27 (20%) demonstrated enhanced uptake. In the 140 myocardial segments with fixed defects on exercise-redistribution thallium imaging, 112 (80%) did not improve after TI-201 reinjection study, and 28 (20%) showed increased activity. The observed agreement on reversibility detection between NTG MIBI and TI-201 reinjection, with the 210 segments with perfusion defects used for this analysis on both studies, was 78%, with a significant kappa = .56 +/- .07 SE.
  
  
  CONCLUSIONS
  Our data suggest that the use of an NTG MIBI protocol results in an incremental improvement for detecting exercise-induced perfusion defect reversibility and achieves results similar to those from a TI-201 reinjection protocol.
authors.affiliation: Center for Clinical Research, Havana, Cuba. cic@cic.sld.cu
authors.forename: J F
authors.initials: JF
authors.lastname: Batista
authors.forename: O
authors.initials: O
authors.lastname: Pereztol
authors.forename: J A
authors.initials: JA
authors.lastname: Valdés
authors.forename: E
authors.initials: E
authors.lastname: Sánchez
authors.forename: R
authors.initials: R
authors.lastname: Stusser
authors.forename: L M
authors.initials: LM
authors.lastname: Rochela
authors.forename: D
authors.initials: D
authors.lastname: López
authors.forename: E V
authors.initials: EV
authors.lastname: Garcia
mesh_terms: D000286:Administration, Sublingual; D000328:Adult; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D012146:Rest; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents
chemical_list: D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D017256:Technetium Tc 99m Sestamibi; D005996:Nitroglycerin