Impact of culprit plaque volume and composition on myocardial microcirculation following primary angioplasty in patients with ST-segment elevation myocardial infarction: virtual histology intravascular ultrasound analysis.

BACKGROUND

An impaired myocardial perfusion state after primary angioplasty is a strong predictor of long-term adverse outcomes in patients with STEMI. We assessed the relationship between culprit plaque characteristics and myocardial perfusion state after primary angioplasty in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

A total of 101 consecutive patients with de novo STEMI were divided into 3 groups according to the state of myocardial perfusion assessed by ST-segment elevation resolution (STR): Group A (complete: STR ≥ 70%, n=26), Group B (partial: STR<70% but ≥ 30%, n=55) and Group C (none: STR<30%, n=20). We analyzed plaque features by virtual histology intravascular ultrasound (VH-IVUS) and assessed the relationship between culprit plaque characteristics and STR after primary angioplasty.

RESULTS

Total plaque volume was significantly higher in Group C than in Groups A and B (146.4 ± 38.0 mm(3)vs. 93.3 ± 29.1 mm(3) and 105.8 ± 31.5 mm(3), p<0.001, respectively). Necrotic core (NC) volume was also significantly higher in Group C than in Groups A and B (25.4 ± 8.0m m(3), vs. 11.9 ± 6.3 mm(3) and 17.3 ± 9.7 mm(3), p<0.001, respectively). Analysis of receiver-operating characteristic curves revealed that total plaque volume and NC volume had the best diagnostic accuracy of all the VH-IVUS parameters to predict STR<30%. The optimal cutoff values (sensitivity/specificity) were 123.4 mm(3) (75.0%/75.3%) for total plaque volume and 20.3mm(3) (75.0%/74.1%) for NC volume.

CONCLUSIONS

Culprit plaque with large plaque burden and high NC volume is closely associated with poor STR after revascularization.