Ten-year follow-up cohort of the everolimus versus azathioprine multinational prospective study focusing on intravascular ultrasound findings.

Background: Long-term clinical outcomes of early intravascular ultrasound (IVUS) findings in a prospective cohort of heart transplantation (HTx) patients have not been evaluated.

Methods: This study included patients from 20 centers across Europe and North and South America among the original cohort of the RAD B253 study. Among these patients, 91 had paired IVUS images at baseline and 1-year post-transplant: everolimus 1.5 mg group (n = 25), everolimus 1.5 mg group (n = 33), and azathioprine 3.0 group (n = 33). The primary outcome was a composite of cardiovascular death, retransplantation, myocardial infarction (MI), coronary revascularization, and cardiac allograft vasculopathy (CAV) within a 10-year follow-up period. The secondary outcome was all-cause death, cardiovascular death, retransplantation, MI, coronary revascularization, and CAV. Donor disease was defined as baseline maximal intimal thickness (MIT) >0.66 mm, and rapid progression was defined as a change in MIT > 0.59 mm at 1 year.

Results: Donor disease (46 patients) was associated with a higher incidence of the primary outcome (hazard ratio (HR) 4.444, 95% confidence interval [CI] 1.946-10.146, p < 0.001). Rapid progression (44 patients) was associated with a significantly higher incidence of the primary outcome (HR 2.942, 95% CI 1.383-6.260, p = 0.005). Higher-risk features on IVUS (positive both donor disease and rapid progression) were independently associated with poor clinical outcomes (HR 4.800, 95% CI 1.816-12.684, p = 0.002).

Conclusions: An increase in baseline MIT and a change in first-year MIT in IVUS post HTx was associated with poor outcomes up to 10 years. Early IVUS findings can be considered as surrogate endpoints for evaluating long-term outcomes in HTx clinical trials.