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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.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.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 (χ(2): 5.510; HR: 1.4; p=0.019), previous acute myocardial infarction (χ(2): 3.867; HR: 1.4; p=0.049), previous coronary revascularization (χ(2): 41.081; HR: 2.5; p0.001), and a positive stress test (χ(2): 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 (χ(2): 4.322; HR: 1.9; p=0.038) who had a first pure pharmacological gated-SPECT (χ(2): 7.182; HR: 2.6; p=0.007).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.

Objective To evaluate the evolutive changes in diastolic function after percutaneous coronary revascularization (PCR) in acute myocardial infarction (AMI), using myocardial perfusion gated SPECT. Methods Thirty-two patients (mean 61.9 ± 9.7 years, 7 women) were studied by two at rest gated SPECT: the first gated-SPECT-1 was performed with an injection of a dose of 99mTc-tetrofosmin prior to PCR and the second gated-SPECT-2 between the fourth and fifth weeks after AMI. Changes of peak filling rate (PFR) and the time to peak filling rate (TTPF) were assessed between both studies, and were related to the extent of salvaged myocardium (SM), end-diastolic (EDV) and end-systolic (ESV) volumes, and left ventricular ejection fraction (LVEF) changes. Results An improvement was observed in diastolic function parameters gated-SPECT-2: PFR increased significantly (p = 0.011) while the TTPF decreased without reaching statistical significance (p = 0.288). In multivariate analysis, adjusted by clinical and coronary variables, improvement of PFR was significantly associated with percentage of SM (p = 0.030), increase in LVEF (p = 0.004) and with ESV volume reduction (p = 0.005). Improvement of TTPF was only related significantly to the percentage of SM (p = 0.046). PFR increased by 0.01 EDV/s. and TTPF decreased by 1.14 ms for each cm2 increase of the area of SM. Conclusions After PCR in AMI, the myocardial perfusion gated SPECT makes it possible to assess the significant improvement in diastolic function mainly related to the amount of MS.