Han, Yushui

Background Coronary microvascular function and hemodynamics may play a role in coronary circulation and myocardial remodeling in patients with aortic stenosis (AS). We aimed to evaluate the relationship between myocardial blood flow and myocardial function in patients with AS, no AS, and aortic valve sclerosis. Methods and Results We included consecutive patients who had resting transthoracic echocardiography and clinically indicated positron emission tomography myocardial perfusion imaging to capture their left ventricular ejection fraction, global longitudinal strain (GLS), and myocardial flow reserve (MFR). The primary outcome was major adverse cardiovascular event (all‐cause mortality, myocardial infarction, or late revascularization). There were 2778 patients (208 with aortic sclerosis, 39 with prosthetic aortic valve, 2406 with no AS, and 54, 49, and 22 with mild, moderate, and severe AS, respectively). Increasing AS severity was associated with impaired MFR ( P <0.001) and GLS ( P <0.001), even when perfusion was normal. Statistically significant associations were noted between MFR and GLS, MFR and left ventricular ejection fraction, and MFR and left ventricular ejection fraction reserve. After a median follow‐up of 349 (interquartile range, 116–662) days, 4 (7.4%), 5 (10.2%), and 6 (27.3%) patients experienced a major adverse cardiovascular event in the mild, moderate, and severe AS groups, respectively. In a matched‐control analysis, patients with mild‐to‐moderate AS had higher rates of impaired MFR (52.9% versus 39.9%; P =0.048) and major adverse cardiovascular event (11.8% versus 3.0%; P =0.002). Conclusions Despite lack of ischemia, as severity of AS increased, MFR decreased and GLS worsened, reflecting worse coronary microvascular health and myocardial remodeling. Positron emission tomography–derived MFR showed a significant independent correlation with left ventricular ejection fraction and GLS. Patients with prosthetic aortic valve showed a high prevalence of impaired MFR.

Abstract Funding Acknowledgements Type of funding sources: None. Background Sarcoidosis is a multi-systemic inflammatory disease of unknown etiology. Cardiac Sarcoidosis (CS) has been reported in as much as 25% of patients with systemic involvement. 18Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) has a high diagnostic sensitivity/specificity in the diagnosis of CS. Purpose The aim of this review is to summarize evidence on the prognostic role of FDG PET. Methods Studies were identified by searching MEDLINE from inception to October 2020. Medical Subject Headings (MeSH) terms for sarcoidosis; cardiac and FDG PET imaging were used. Studies of any design assessing the prognostic role of FDG PET in patients with either suspected or confirmed cardiac sarcoidosis imaging done at baseline were included. Abnormal PET was defined as abnormal metabolism (presence of focal or focal-on-diffuse uptake of FDG) OR abnormal metabolism and a perfusion defect. Studies reporting any outcome measure were included. Pooled risk ratio for the composite outcome of MACE was done. Results A total of 6 studies were selected for final inclusion (515 patients, 53.4% women, 19.8% racial minorities.) Studies were institution based, retrospective in design and enrolled consecutive patients. All were observational in nature and published in English. All studies used a qualitative assessment of PET scans (abnormal FDG uptake with or without abnormal perfusion). Two studies assessed quantitative metrics (summed stress score in segments with abnormal FDG uptake, standardized uptake value and cardiac metabolic activity.) All studies reported Major Adverse Cardiovascular Events (MACE) as a composite outcome. After a mean follow up ranging from 1.4 to 4.1 years, there were a total of 105 MACE. All studies included death (either all-cause death or sudden cardiac death) and ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation) as a component of MACE. Four of the six studies adjusted for several characteristics in their analysis. All four studies used Left Ventricular Ejection Fraction (LVEF). However, other adjustment variables were not consistent across studies. Five studies found a positive prognostic association with the primary outcome, two of which assessing right ventricular uptake. Conclusion Although available evidence indicates FDG PET can be used in the risk stratification of patients with CS, our findings show further studies are needed to quantify the effect in this patient group.