Visually Estimated Coronary Artery Calcium is an Independent Prognostic Marker Following Heart Transplantation.

Cardiac positron emission tomography (PET) has been used for surveillance of cardiac allograft vasculopathy (CAV) following heart transplant (HT). Visually estimated coronary artery calcium (VECAC) can be quantified during PET and has been associated with adverse cardiovascular outcomes in CAD. The utility of VECAC following HT has not been established, and given the differing pathophysiology of CAV and CAD, we investigated the prognostic value of VECAC following HT. We performed a retrospective analysis of all consecutive adult HT patients who underwent N-13 cardiac PET 2016-2019 with follow-up through June 30, 2022. VECAC categories were defined as: 0 (V0, n=319), 1-9 (V1, n=44), 10-99 (V2, n=34), and 100+ (V3, n=33). The association between baseline VECAC categories and various outcomes was assessed using univariate and multivariable Cox regression. The primary outcome was death or retransplantation. 430 patients were identified with median age of 61 years and time post HT of 4.3 years. 73% were male, 33% had diabetes, 67% had GFR<60, and median BMI was 26. Compared with V0, VECAC categories V2 (HR 2.2, 95% CI 1.2-4.1, p=0.009) and V3 (HR 3.4, 95% CI 2.0-6.0, p<0.001) were associated with an increased risk of death/retransplantation (Figure 1). While V2 was not statistically associated with CV death (HR 2.0, 95% CI 0.83-5.0, p=0.1), V3 was (HR 2.6, 95% CI 1.1-6.1, p=0.03). Adjusting for risk factors including angiographic CAV, myocardial blood flow reserve (MBFR), GFR<60, DM, age, and time post HT, V2 (HF 1.9, 95% CI 1.0-3.6, p=0.05) and V3 (HR 2.9, 95% CI 1.5-5.7, p=0.001) remained associated with death/retransplantation. Interaction testing with MBFR demonstrated that V3 was consistently associated with death/retransplantation (MBFR<2: HR 3.1, p=0.01; MBFR>2: HR 2.8, p=0.007), while V2 was only associated with death/retransplantation when MBFR>2 (HR 2.3, p=0.04). VECAC is an independent prognostic marker of death or retransplantation following HT. [ABSTRACT FROM AUTHOR]