title: Prognostic value of SPECT myocardial perfusion imaging in patients with elevated cardiac troponin I levels and atypical clinical presentation.
abstract: BACKGROUND
  We determined the prognostic value of myocardial perfusion imaging (MPI) in patients with atypical clinical presentations and unexpected elevation of cardiac troponin I (cTnI) levels.
  
  
  RESULTS
  In 156 consecutive patients with atypical presentations for acute coronary syndromes (ACS) and elevated cTnI levels undergoing MPI within 30 days, rates of all-cause mortality (100% follow-up; median follow-up, 611 days) and 6-month cardiac death and nonfatal myocardial infarction (96% follow-up; median follow-up, 167 days) were determined. The mean age of the patients was 68 +/- 14 years. The majority of the study cohort (96%) was at low to intermediate clinical risk for ACS (Thrombolysis in Myocardial Infarction score for unstable angina/non-ST-segment elevation myocardial infarction <5). The overall event rate was high, with 45 deaths (28.8%). There were 13 cardiac deaths/nonfatal myocardial infarctions in 6 months (8.3%). A normal MPI result was associated with a high event-free survival rate, whereas an abnormal MPI result was associated with a 3-fold and 7-fold higher risk of all-cause mortality and 6-month cardiac events, respectively. An abnormal MPI result was an independent predictor of all-cause death.
  
  
  CONCLUSIONS
  In patients with cTnI elevation and a low to intermediate risk for ACS, a normal MPI result portends a good prognosis. Patients with abnormal MPI results have a higher 6-month cardiac event rate and a worse survival rate.
authors.affiliation: Division of Nuclear Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. sdorbala@partners.org
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dorbala
authors.forename: Robert P
authors.initials: RP
authors.lastname: Giugliano
authors.forename: Giridhar
authors.initials: G
authors.lastname: Logsetty
authors.forename: Divya
authors.initials: D
authors.lastname: Vangala
authors.forename: Rakesh
authors.initials: R
authors.lastname: Mishra
authors.forename: Sharon
authors.initials: S
authors.lastname: Crugnale
authors.forename: David
authors.initials: D
authors.lastname: Yang
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Di Carli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging*; D015415:Biomarkers / Q000097:blood; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D016019:Survival Analysis; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019275:Radiopharmaceuticals; D019210:Troponin I; D017256:Technetium Tc 99m Sestamibi