BACKGROUND AND PURPOSE:Increased oxygen extraction fraction on PET has been considered a risk factor for stroke in patients with carotid stenosis or occlusion, though the strength of this association has recently been questioned. We performed a systematic review and meta-analysis to summarize the association between increased oxygen extraction fraction and ipsilateral stroke risk.

Objectives To assess patterns and functional consequences of mitral apparatus infarction after acute MI (AMI). Background The mitral apparatus contains two myocardial components – papillary muscles and the adjacent LV wall. Delayed-enhancement CMR (DE-CMR) enables in-vivo study of inter-relationships and potential contributions of LV wall and papillary muscle infarction (PMI) to mitral regurgitation (MR). Methods Multimodality imaging was performed: CMR was used to assess mitral geometry and infarct pattern, including 3D DE-CMR for PMI. Echocardiography (echo) was used to measure MR. Imaging occurred 27±8 days post-AMI (CMR, echo within 1 day). Results 153 patients with first AMI were studied. PMI was present in 30% (n=46; 72% posteromedial, 39% anterolateral). When stratified by angiographic culprit vessel, PMI occurred in 65% of patients with left circumflex, 48% with right coronary, and only 14% of patients with left anterior descending infarctions (p<0.001). Patients with PMI had more advanced remodeling as measured by LV size and mitral annular diameter (p<0.05). Increased extent of PMI was accompanied by a stepwise increase in mean infarct transmurality within regional LV segments underlying each papillary muscle (p<0.001). Prevalence of lateral wall infarction was 3.0 fold higher among patients with, compared to those without, PMI (65% vs. 22%, p<0.001). Infarct distribution also impacted MR, with greater MR among patients with lateral wall infarction (p=0.002). Conversely, MR severity did not differ based on presence (p=0.19) or extent (p=0.12) of PMI, or by angiographic culprit vessel. In multivariable analysis, lateral wall infarct size (OR=1.20[CI=1.05–1.39], p=0.01) was independently associated with substantial (≥moderate) MR even after controlling for mitral annular (OR=1.22[1.04–1.43], p=0.01) and LV end-diastolic diameter (OR=1.11 [0.99–1.23], p=0.056). Conclusions PMI is common post-AMI, affecting nearly one-third of patients. PMI extent parallels adjacent LV wall injury, with lateral infarction – rather than PMI - associated with increased severity of post-AMI MR.