Introduction: Cardiac allograft vasculopathy (CAV) affects >50% of OHT recipients by 10 years and is a leading cause of mortality. Standard CAV screening is via invasive coronary angiography (ICA). Recently it has been shown that PET with myocardial blood flow (PET/MBF) has excellent diagnostic ability for CAV, however, its prognostic value is not known. Hypothesis: CAV assessment by PET/MBF can prognosticate lack of significant angiographic progression of CAV over meaningful time scales. Methods: A retrospective analysis of 206 OHT recipients who underwent a PET/CT between ICAs was performed. CAV progression over time was assessed using intra-patient sequences of 1) baseline ICA, 2) interval PET, and 3) subsequent ICA. PET CAV grades were determined using the algorithm in Table 1. For each interval, NPV of CAV development was calculated. Results: Intervals between ICAs of 600, 800, 1000, and 1200 days were included with 77, 114, 106, and 22 patients respectively. Sequences were analyzed if the PET fell within middle third of interval. For development of ISHLT CAV 2/3 on subsequent ICA, PET CAV 0/1 had an NPV of 0.91, 0.94, 0.91, and 0.86 at each respective time point. For development of meaningful ISHLT CAV (presence of ≥ 30% vessel stenosis) on subsequent ICA, PET CAV 0/1 had an NPV of 0.80, 0.85, 0.85, 0.8 respectively (Figure 1). Conclusions: Non-invasive CAV assessment by PET/MBF provides robust NPV for development of varying degrees of clinically significant CAV over intervals up to 4 years. PET may be used as an adjunct to ICA for CAV screening and is a viable alternative among those with reasonable risk profiles. Prospective studies are needed to determine optimal interval lengths.