Placebo or trimetazidine (99m)Tc tetrofosmin myocardial SPECT and low-dose dobutamine echocardiography in hibernating myocardium.

Background: Trimetazidine (TMZ) improves (99m)Tc sestamibi uptake in myocardial single photon emission tomography (SPECT). This study compared TMZ (99m)Tc tetrofosmin SPECT and low-dose dobutamine echocardiography (LDDE) as predictors of functional recovery of hibernating myocardium after coronary revascularization.
Methods: Thirty-one patients with prior myocardial infarction and left ventricular dysfunction underwent coronary angiography, LDDE, placebo SPECT and TMZ SPECT. Echocardiographic follow-up was obtained at 2/6 months; the clinical follow-up lasted 2 years.
Results: Twenty-three (74.2%) patients (195 dysfunctioning left ventricular segments) were revascularized. TMZ improved (99m)Tc tetrofosmin uptake (p = 0.0001) as well as LVEF at gated SPECT (p = 0.04). At 2-months, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated (LDDE 71.9, 78.7, 71, 79.5; placebo SPECT 66.2, 75.6, 65.4, 76.3; TMZ SPECT 79.2, 67.7, 61.6, 83.3, respectively). The specificity improved in placebo and TMZ SPECT (82.1 and 78.7%) at 6-months follow-up. Two patients (2/23) with hibernating myocardium treated with revascularization and three (3/4) treated medically died a cardiac death (p = 0.0016, log rank 12.89). None (0/4) without viability died during the 2-year follow-up (p = 0.6, log rank 0.28).
Conclusions: The addition of TMZ to (99m)Tc tetrofosmin SPECT improved diagnostic accuracy. The importance of hibernating myocardium revascularization was confirmed.