Apical remodeling may be identified in gated myocardial perfusion SPECT by the presence of a divergent pattern (DP) of the left ventricle (LV). The incidence and implications of DP in patients with anterior acute myocardial infarction (AMI) successfully treated with primary percutaneous coronary interventions (PCI) are unclear.
We examined 151anterior AMI patients, all successfully treated with PCI early after symptom onset. Perfusion gated SPECT to measure infarct size, infarct severity, LV end-diastolic (ED) and end-systolic (ES) volumes and ejection fraction (EF)was acquired before hospital discharge and repeated at 6-month follow up.
DP was observed in 26 patients. Patients with DP had larger infarct size (28 ±19% vs. 15.7 ± 17%, p<0.02), greater infarct severity (0.31 ± 0.13 vs. 0.43 ± 0.17, p < 0.02), larger ESV (90 ± 32 vs. 67 ± 36 ml, p < 0.05) and a significantly lower EF (33 ± 7% vs. 41 ± 10%, p<0.001), but not larger EDV (132 ± 39 vs. 110 ± 42 ml, NS) than the other patients. At follow-up, the DP patients had significantly larger EDV (156 ± 54 vs. 107 ± 44 ml, p < 0.0001), ESV (104 ± 47 vs. 59 ± 36 ml, p < 0.0001) and lower EF (35 ± 12% vs. 48 ± 13%, p<0.0001) than the patients without DP. Of the DP patients, 54% developed remodeling at follow-up vs. 12% of those without DP (p<0.001). Therefore, DP showed sensitivity of 48%, specificity of 90%, positive predictive value of 54%, negative predictive value of 88%, and diagnostic accuracy of 82% for the presence of remodeling at 6-month follow-up.
During follow up there were 7 events in the DP group and 11 events in patients without DP. Kaplan Meier survival curves showed a worse prognosis for patients with DP (Log rank test: p<0.01).
In patients with anterior AMI,DP detection early after the acute event is related to premature ventricular dysfunction, and to larger infarct size and worse severity. Moreover, early DP detectionhas an important prognostic value and can be useful for predicting LV remodeling at 6-month follow-up.