Variables that influence the indication of a second myocardial perfusion gated-SPECT after a normal stress-rest gated SPECT.

Objective: The objective of this study was to investigate predictor variables at the moment of normal stress-rest myocardial perfusion gated SPECT for indication of a second gated SPECT. Material and Methods: A prospective, single center cohort study was conducted. We evaluated 2326 consecutive patients (age 63.6. ±. 13 years, 57.3% females) without perfusion defects and with normal left ventricular ejection fraction on a myocardial perfusion gated SPECT. Clinical and stress test variables were studied to predict indication of a second gated SPECT and presence of reversible perfusion defects in the second gated SPECT. Results: During a mean follow-up of 3.6±2 years a second gated SPECT was performed in 286 patients (12.3%). Independent predictor variables of a second gated SPECT were presence of three or more cardiovascular risk factors (χ2: 5.510; HR: 1.4; p=0.019), previous acute myocardial infarction (χ2: 3.867; HR: 1.4; p=0.049), previous coronary revascularization (χ2: 41.081; HR: 2.5; p<0.001), and a positive stress test (χ2: 8.713; HR: 1.5; p=0.003). Observation of perfusion defects in the 280 patients in whom a second stress-rest gated SPECT was performed was more likely in male patients (χ2: 4.322; HR: 1.9; p=0.038) who had a first pure pharmacological gated-SPECT (χ2: 7.182; HR: 2.6; p=0.007). Conclusions: In patients with a first normal myocardial perfusion gated SPECT, various clinical factors and variables derived from the stress test affect the indication of a second gated SPECT and the presence of ischemia in the latter. © 2013 Elsevier España, S.L. and SEMNIM.