The predictive value of coronary artery calcium detected by computed tomography in a prospective study on cardiac allograft vasculopathy in heart transplant patients

The predictive value of coronary artery calcium (CAC) in heart transplant (HTX) patients is not established. We explored if the absence of CAC on computed tomography (CT) could exclude moderate and severe cardiac allograft vasculopathy [CAV_2-3 ; the International Society for Heart and Lung Transplantation (ISHLT) recommended nomenclature] and significant coronary artery stenosis (diameter reduction ≥50%) and predict long-term clinical outcomes. HTX recipients (n = 133) were prospectively included and underwent CT for CAC scoring and invasive coronary angiography (ICA) 7.8 ± 5.0 years after HTX. CAC was detected in 73 (55%) patients. The absence of CAC on CT had a negative predictive value of 97% for ISHLT CAV_2-3 and 88% for significant stenosis on ICA. During 7.5 ± 2.6 years of follow-up after CAC CT (n = 127), there were 57 (45%) nonfatal major adverse cardiac events and 23 (18%) deaths or graft losses registered as first events. Patients with CAC had significantly more events (P = 0.011). In an adjusted Cox regression analysis, the presence of CAC was significantly associated with a negative outcome (HR 1.8, 95% CI 1.1-3.0; P = 0.023). The absence of CAC predicted low prevalences of ISHLT CAV_2-3 and significant coronary artery stenosis in HTX patients. The presence of CACS was significantly associated with a worse long-term outcome.