title: [Evaluation of myocardial viability using perfusion cardiac SPECT. 201-thallium rest/redistribution, 201-thallium rest/reinjection and technetium 99m tetrofosmin rest/postnitrates].
abstract: OBJECTIVE
  It has been demonstrated that nitrate administration enhances the detection of myocardial viability in thallium-201 and technetium-99m sestamibi myocardial perfusion studies. The aim of this study was to assess the influence of nitrate administration on technetium-99m tetrofosmin myocardial uptake in patients with coronary artery disease and left ventricular dysfunction.
  
  
  METHODS
  Twenty eight patients with coronary artery disease, previous myocardial infarction and left ventricular ejection fraction < 40% underwent, within 48 hours, rest/postnitroglycerin (0.4 mg sublingually) technetium-99m tetrofosmin single photon emission tomography (SPET), comparing these results with that of thallium-201 rest/redistribution SPET in 13 patients (first group) and with that of thallium-201 rest/reinjection SPET in the other 15 patients (second group). Tomograms based on the 3 spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake > or = 50% of peak activity.
  
  
  RESULTS
  The percentage of peak activity at rest or after nitrate administration of technetium-99m tetrofosmin correlated, with that of thallium-201, at rest and after redistribution or reinjection (r = 0.8; p < 0.001). On resting technetium-99m tetrofosmin studies 167 of the 420 segments that were analysed had < 50% of peak activity. 14.5% of these segments showed reversibility after nitrate administration, with an increase in 99mTc-tetrofosmin uptake from 45 +/- 5% to 55 +/- 4% of peak activity (p = 0.001), in the first group, and from 40 +/- 9% to 57 +/- 9% of peak activity (p = 0.003), in the second group. Overall agreement between rest/postnitroglycerin technetium-99m tetrofosmin SPET studies and rest/redistribution or rest/reinjection thallium-201 SPET studies, regarding the presence of myocardial viability, was 87% and 90%, respectively. All except one reversible segments on tetrofosmin studies after nitrates had viability criteria on thallium studies.
  
  
  CONCLUSIONS
  Nitrate administration at rest enhances the detection of myocardial viability using technetium-99m tetrofosmin SPET, correlating with viability criteria observed on thallium studies. It represents a simple and useful technique in the assessment of myocardial viability.
authors.affiliation: Servicio de Medicina Nuclear, Hospital de la Santa Creu i Sant Pau, Barcelona.
authors.forename: A
authors.initials: A
authors.lastname: Flotats Giralt
authors.forename: I
authors.initials: I
authors.lastname: Carrió Gasset
authors.forename: M
authors.initials: M
authors.lastname: Estorch Cabrera
authors.forename: L
authors.initials: L
authors.lastname: Bernà Roqueta
authors.forename: A M
authors.initials: AM
authors.lastname: Catafau Alcántara
authors.forename: C
authors.initials: C
authors.lastname: Marí Aparici
authors.forename: M
authors.initials: M
authors.lastname: Ballester Rodés
mesh_terms: D000368:Aged; D002985:Clinical Protocols; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; C078700:technetium tc-99m tetrofosmin