Abstract 4513: Plaque Regression Determined by Intravascular Ultrasound Predicts Long-term Outcomes in Patients With Acute Coronary Syndrome
Introduction: Several recent clinical trials have evaluated plaque regression using intravascular ultrasound (IVUS) to assess the impact of medical therapies. However, scant data link plaque regression with clinical outcomes in patients with acute coronary syndrome (ACS).
Hypothesis: We assessed the hyposesis that plaque regression determined by IVUS predicts long-term clinical outcomes.
Methods and results: Among the 180 patients who participated in the Extended-ESTABLISH trial, the present study enrolled 86 of those with ACS who underwent percutaneous coronary intervention (PCI) and who were completely assessed at baseline and at 6-months of follow-up by measuring proximal non-culprit sites of PCI lesions using volumetric IVUS. Plaque regressed in 55 (61.8%) patients and progressed in 31 (38.2%). We thus assigned the patients to either regression or progression groups. The baseline characteristics at the time of ACS occurrence were similar between the two groups. Patients were subsequently followed up observationally for a mean of 1,736 days. During the follow-up period, 13 patients developed major adverse cardiac and cerebrovascular events (MACCE). Event free survival probability was significantly higher in the regression, than in the progression group estimated by Kaplan-Meier methods (Log-rank test, p=0.032). Furthermore, plaque regression was associated with a lower risk of MACCE (Hazard ratio: 0.28; 95% CI, 0.09 – 0.93; p=0.037).
Conclusions: Plaque regression with volumetric IVUS over 6 months predicted good long-term outcomes for patients with ACS. Furthermore, this study demonstrated that plaque regression could be a surrogate marker of MACãCE.