early risk stratification using rubidium-82 positron emission tomography in stemi patients

Assessment of infarct size after myocardial infarction is predictive of subsequent morphological changes and clinical outcome. this study aimed to assess subacute post-intervention rubidium-82 (82rb)-pet imaging in predicting left ventricle ejection fraction, regional wall motion, and final infarct size by cmr at 3-months after stemi. stemi patients undergoing percutaneous coronary intervention were included prospectively. rest-only 82rb-pet perfusion imaging was performed at median 36 hours [iqr: 22 to 50] after the treatment. the extent of hypoperfusion and absolute blood flow (ml·min·g) were estimated on a global and a 17-segment model with dedicated software. at 3-months follow-up patients completed the cmr functional and late gadolinium enhancement imaging. 42 patients were included, but only 35 had follow-up cmr and constituted the study population. absolute blood flow was significantly lower in the infarct-related territory compared to remote myocardium, p < .005. extent of hypoperfusion correlated with final infarct size, r = 0.58, p < .001, while blood flow correlated with ejection fraction, r = 0.41, p < .05. in linear mixed models, higher subacute absolute blood flow (β = 4.6, confidence interval [3.5; 5.2], p < .001, r2 = 0.67) was associated with greater wall motion. segmental extent of subacute hypoperfusion (β = 0.43 [0.38; 0.49], p < .001, r2 = 0.58) was associated with the degree of late gadolinium enhancement at 3-months. subacute rest-only 82rb-pet is feasible following stemi and seems predictive of myocardial function and infarct size at 3-months.