Usefulness of tissue doppler parameters to identify single-vessel circumflex lesion from non ST-elevation myocardial infarction

Background: Some cases of left circumflex artery (LCX)-culprit infarction, even with single-vessel disease, may be non ST-elevation myocardial infarction (NSTEMI). This study was conducted to identify this group from other NSTEMI. Methods: Two hundred patients underwent coronary angiography for NSTEMI. Tissue Doppler imaging (TDI) measurements were performed simultaneously. Results: Most subjects had multi-vessel disease except for 13 patients with single-vessel LCX disease. The prevalence of diabetes, hypertension, and renal insufficiency in the group of single-vessel LCX disease was relatively low. Since left ventricular ejection fraction was preserved in the majority of subjects, the rates of respiratory failure, cardiogenic shock and high left ventricular filling pressure were lower in the group of single-vessel disease than that in the other NSTEMI patients. Therefore, the in-hospital mortality rate differed between these two groups (0% vs. 6%, respectively). By receiver operating characteristic curve analysis, lateral myocardial performance index (MPI) divided by mean MPI was a good indicator of single-vessel LCX disease (lateral MPI / mean MPI > 1.17, with sensitivity 92%, specificity 84%, and p < 0.0001). Conclusion: TDI is useful for identifying patients with single-vessel LCX disease.