Tissue characteristics in non-culprit lesions during the acute coronary event and at ten months follow-up

Abstract

Introduction: It is not well established how the medication recommended in the guidelines will affect plaque compositional changes in non-culprit segments after STEMI. We hypothesized that the proportion of necrotic tissue in the non-culprit lesion in the culprit artery would decrease ten months after STEMI. Methods: In 63 consecutive STEMI patients the non-culprit segment in the culprit artery was analyzed with iMap intravascular ultrasound (IVUS) at the time of the index procedure and 10 months later. The non-culprit segment was identified as being 20mm proximal to the most stenotic culprit segment. All patients were recommended to receive the drug therapy outlined in the STEMI guidelines. Results: The proportion of necrotic tissue in the non-culprit segment proximal to the culprit lesion was high at the index event and was unchanged at 10 months follow-up (27.1±11.9 (%) vs 25.5±12.8 (%), p=0.147). Similarly, proportion of calcific tissue did not change after ten months in the non-culprit lesion (2.0±1.5 (%) vs 2.1±1.7 (%), p= 0.373). The percentage of lipidic tissue ((9.8±2.9 (%) vs 8.8±3.0 (%), p=0.009) decreased at 10 months follow-up, but the percentage of fibrotic tissue (61.2±14.3 (%) vs 63.6±14.9 (%), p=0.05) increased in the non-culprit segment ten months after STEMI. Conclusions: The percentage of necrotic tissue remained high, however, the proportion of lipidic tissue decreased and the proportion of fibrotic tissue increased in the non-culprit segment ten months after STEMI.