PET/CTA detection of muscle inflammation related to cholesterol crystal emboli without arterial obstruction.

BACKGROUND: PET/CTA was used to evaluate the effect of cholesterol crystal emboli (CCE) on muscle injury. Cholesterol crystals (CCs) released during plaque rupture travel downstream and lodge in muscle triggering inflammation and tissue injury. METHODS: Thigh muscles in three groups of rabbits (n = 22) were studied after intra-arterial injection of CCs, Group I (n = 10); polystyrene microspheres, Group II (n = 5); or normal saline, Group III (n = 7). After 48 hours, muscle inflammation and injury were measured by fluorodeoxy-glucose uptake using PET/CTA, serum tissue factor (TF), and creatinine phosphokinase (CPK). Macrophages were stained with RAM11 and CCs with Bodipy. RESULTS: SUVmax of thigh muscles was greater for Group I vs Group II and III (0.40 ± 0.16 vs 0.21 ± 0.11, P = .038 and 0.23 ± 0.06, P = .036). CPK levels rose significantly in Group I vs Group II and III (6.7 ± 6.0 vs 0.6 ± 0.4, P = .007 and 0.9 ± 0.4 mg·dL-1, P = .023). No arterial thrombosis was detected by CTA or histology of embolized arteries and TF did not rise significantly. There were extensive macrophage infiltrates surrounding muscle necrosis in Group I only. CONCLUSIONS: Cholesterol crystal emboli triggered muscle inflammation and necrosis with an intact circulation. PET/CTA may help in the early detection of inflammation caused by CCs.

Periprocedural myocardial infarction in a randomized trial of everolimus-eluting and Paclitaxel-eluting coronary stents: frequency and impact on mortality according to historic versus universal definitions.

BACKGROUND: A consensus definition for periprocedural myocardial infarction (MI) in coronary stent trials has not been established. Differences between a historic definition, based on modified World Health Organization (WHO) criteria, and a proposed universal definition have not been compared in a prospective clinical trial. METHODS AND RESULTS: We randomly assigned 3687 patients with stable coronary artery disease to undergo stenting with either everolimus-eluting stents (2458 patients) or paclitaxel-eluting stents (1229 patients). Serial creatine kinase (CK) and CKMB or troponin measurements were obtained before and after stenting. MI was classified by protocol according to the WHO definition (total CK >2× normal with elevated CKMB) and post hoc according to the Universal/Academic Research Consortium (ARC) definition (CKMB or troponin >3× normal). Protocol MI was determined in 58 (1.6%) and universal/ARC MI in 287 (7.8%) patients within 48 hours post index procedure. There were substantial differences in frequency of universal/ARC MI if only CKMB (5.4%) or troponin (18.7%) data were included for evaluation. Total stent length was a strong predictor of both protocol and universal/ARC MI. Mortality at 2 years was low (2.3%) and was not different for either MI definition. The mortality rates did not increase with elevations of CKMB or troponin to >10× normal. CONCLUSIONS: There was a marked difference in periprocedural MI rates according to protocol or universal/ARC MI definitions. No association was present between periprocedural MI and mortality up to 2 years by either definition. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00307047.