'False-positive' myocardial perfusion imaging: correlation with cardiovascular risk factors and effect on event-free survival.
BACKGROUND
In the absence of significant coronary stenoses, stress-induced myocardial perfusion abnormalities at gated single photon emission computed tomography (g-SPECT) are usually considered to be a 'false-positive' result. Our goal was to investigate how false-positive g-SPECT perfusion abnormalities relate to cardiovascular risk factors and whether they provide any prognostic information.


METHODS
From 1999 to 2005, a group of 130 anginal patients with myocardial perfusion abnormalities at stress g-SPECT, with normal coronary angiography or less than 50% lumen reduction and with a left ventricular ejection fraction more than 0.45, was selected. The extent of myocardial perfusion abnormalities after stress was quantified using the summed difference score (SDS).


RESULTS
Using a logistic regression model, it was found that cardiovascular risk factors (diabetes mellitus, arterial hypertension, smoking habit, hypercholesterolemia and obesity) were closely related (r = 0.96) to the SDS. During a 44 +/- 7-month follow-up, six patients experienced nonfatal cardiac events. An SDS more than 7 (P < 0.0001) and diabetes mellitus (P < 0.0001) were the only independent predictors of event-free survival using Cox proportional hazard regression analysis.


CONCLUSIONS
In patients with anginal-like chest pain and without significant coronary stenoses, stress-induced myocardial perfusion abnormalities at g-SPECT correlate with cardiovascular risk factors and are independent predictors of the few, minor adverse cardiac events during the follow-up.
CNR, Clinical Physiology Institute, Pisa, Italy. gimelli@ifc.cnr.it
Alessia
A
Gimelli
Paolo
P
Marzullo
Antonio
A
L'Abbate
Daniele
D
Rovai
D000368:Aged; D000787:Angina Pectoris / Q000453:epidemiology; D003326:Coronary Circulation; D003920:Diabetes Mellitus / Q000453:epidemiology; D004176:Dipyridamole; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D009765:Obesity / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D004176:Dipyridamole