OBJECTIVES: In the CHAMPION PHOENIX trial, the platelet inhibitor cangrelor reduced 48-hour incidence of Major Adverse Cardiac Events (MACE --death, MI, stent thrombosis, or repeat ischemia-driven revascularization) compared to a loading dose of clopidogrel in percutaneous coronary intervention (PCI). Investigators also analyzed outcomes according pre-specified angiographic high-risk characteristics. PHOENIX ECONOMICS examined costs associated with procedural thrombotic complications occurring during PCI. This analysis is conducted to determine if patients with angiographic high-risk features are more costly to hospitals. METHODS: Costs were estimated according to the number of angiographic high-risk lesion characteristics present (bifurcation, left main, thrombus, angulated, tortuous, eccentric, calcified, long (>20 mm), or multi-lesion PCI), based on the database from the PHOENIX ECONOMICS study (1,117 patients from 21 US sites). Patients’ initial hospital bills were collected and costs calculated from hospital departmental-level cost-to-charge-to- ratios. RESULTS: Previous CHAMPION PHOENIX reports associated angiographic complexity with increasing clinical risk (MACE rates of 2.5%, 4.1%, 6.5%, 7.5% in 0, 1, 2, and >=3 risk features, respectively). Mean per-PCI hospital costs in the PHOENIX ECONOMICS population increased progressively from $10,291 to $11,491 to $13,258 to $16,425, respectively. In a random effects model, the number of risk features was an independent predictor of increased hospital costs, with each risk feature increasing costs by $523 (95% CI=[$279, $768], p<0.0001) per patient after adjustment of patient demographic, device costs, anticoagulant use, and other procedure characteristics. CONCLUSIONS: In US patients undergoing PCI, the number of angiographic high-risk features treated is a powerful predictor of 48 hour MACE and increased hospital costs; each risk factor increasing costs >$500. The cost increase is likely driven by MACE, due to adjustment for patient demographic, device costs, anticoagulant use, and other procedure characteristics. Identifying patients with angiographic risk features and deploying effective therapies to mitigate clinical risk may relieve both a clinical and economic burden to hospitals.