Prognostic value of SPECT myocardial perfusion imaging in patients with elevated cardiac troponin I levels and atypical clinical presentation.
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.
Dorbala
Sharmila
S
Division of Nuclear Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. sdorbala@partners.org
Giugliano
Robert P
RP
Logsetty
Giridhar
G
Vangala
Divya
D
Mishra
Rakesh
R
Crugnale
Sharon
S
Yang
David
D
Di Carli
Marcelo F
MF
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*
D015415:Biomarkers; D019275:Radiopharmaceuticals; D019210:Troponin I; D017256:Technetium Tc 99m Sestamibi