OBJECTIVE: Evaluate whether Tc-99m tetrofosmin (TF) SPECT myocardial perfusion imaging can predict coronary microvascular dysfunction in patients with acute myocardial infarction. METHODS AND RESULTS: Immediately after percutaneous coronary intervention in 25 patients with an acute myocardial infarction, SPECT imaging was performed, and a regional severity score index (RSSI) was calculated. Using a Doppler guidewire, the deceleration time of diastolic flow velocity (DDT) after percutaneous coronary intervention was calculated. A DDT of 600 milliseconds or less was defined as an indicator of coronary microvascular dysfunction. A regional wall motion score index (RWMSI) was obtained during the chronic phase. The correlation between RSSI and DDT was good(r = -0.68, P < .01). The RSSI cutoff value of 1.9 or greater had a sensitivity of 100% and specificity of 71% in predicting DDT. Those with poor scintigraphic coronary microvascular function (RSSI > or =1.9, n = 7) had a significantly shorter DDT (P = .0003), a lower frequency of early systolic retrograde flow (P = .0038), and greater chronic RWMSI (P = .0015) than the group with good scintigraphic coronary microvascular function. CONCLUSIONS: SPECT myocardial perfusion and function scanning immediately after percutaneous coronary intervention in patients with acute myocardial infarction is a useful noninvasive method for evaluating coronary microvascular dysfunction.

COMMENT: an abnormal SPECT myocardial perfusion and function scan immediately after percutaneous coronary intervention can be an early indicator of coronary microvascular dysfunction.

J Nucl Cardiol. 2004 Sep-Oct;11(5):562-9.

Noninvasive assessment of coronary microvascular dysfunction using Tc-99m tetrofosmin SPECT in patients with acute myocardial infarction.

Abe Y, Kondo M, Kubota T, Matsuoka R, Araki M, Doyama K, Tanio H.

Division of Cardiology, Shimada Municipal Hospital, Shimada City, Shizuoka 427-8502, Japan.