Remote ischaemic conditioning in ST elevation myocardial infarction: a registry-based randomised trial.

OBJECTIVES: Remote ischaemic conditioning (RIC) has been tested as a possible strategy for mitigating reperfusion injury in ST elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PPCI). However, surrogate outcomes have shown inconsistent effects with lack of clinical correlation. METHODS: We performed a registry-based randomised study of patients with STEMI allocated to RIC (4 cycles of blood pressure cuff inflation to 200 mm Hg for 5 min of ischaemia followed by 5 min of reperfusion) or standard of care (SOC) during PPCI. We examined the associations of RIC on core laboratory measurements of myocardial perfusion, infarct size (IS), left ventricular (LV) performance and clinical outcomes. RESULTS: A total of 252 patients were enrolled. The median age was 61 (IQR: 55-70) years and 72.8% were male. Sum ST segment deviation resolution ≥50% was similar between RIC and SOC (65.2% vs 55.7%, p=0.269). In those with 3-day cardiovascular MRI (n=88), no difference in median (25th, 75th percentiles) IS (14.9% (4.5%, 23.1%) vs 16.1% (3.3%, 22.0%), p=0.980), LV dimensions (LV end-diastolic volume index: 78.7 (71.1, 91.2) mL/m2 vs 79.9 (71.2, 88.8) mL/m2, p=0.630; LV end-systolic volume index: 48.8 (35.7, 51.4) mL/m2 vs 37.9 (31.8, 47.5) mL/m2, p=0.551) or ejection fraction (50.0% (41.0%-55.0%) vs 50.0% (43.0%-56.0%), p=0.554) was demonstrated. Similar results were observed with 90-day cardiovascular MRI. At 1 year, the clinical composite of death, congestive heart failure, cardiogenic shock and recurrent myocardial infarction was similar in RIC and SOC (21.7% vs 13.3%, p=0.110). CONCLUSIONS: In a contemporary registry-based randomised study of patients with STEMI undergoing PPCI, adjunctive therapy with RIC did not improve myocardial perfusion, reduce IS or alter LV performance. Consequently, there was no difference in clinical outcomes within 1 year. TRIAL REGISTRATION NUMBER: NCT03930589.

Utility of FDG PET and Cardiac MRI in Diagnosis and Monitoring of Immunosuppressive Treatment in Cardiac Sarcoidosis.

PURPOSE: To compare the contributions of cardiac MRI and PET in the diagnosis and management of cardiac sarcoidosis (CS), with particular reference to quantitative measures. MATERIALS AND METHODS: This is a retrospective, observational study of 31 patients (mean age, 45.7 years) with proven extracardiac sarcoidosis and possible CS who were investigated with fluorine 18 fluorodeoxyglucose (FDG) PET/CT and cardiac MRI. Patients were treated at physicians' discretion with repeat combined imaging after an interval of 102-770 days (median, 228 days). RESULTS: Significant myocardial FDG uptake was shown on visit 1 (myocardial maximum standardized uptake value [SUVmax] > 3.6) in 17 of 22 patients who were subsequently treated. Myocardial SUVmax decreased at follow-up (6.5 to 4.0; P < .01) and was matched by significant decreases in FDG-avid lung and mediastinal node disease. A volumetric measure of myocardium above a threshold SUV (cardiac metabolic volume) decreased from a mean of 42.5 to a mean of 4.1 (P < .001). This was associated with significant improvement in the left ventricular ejection fraction (LVEF) (45.8 increasing to 50.9; P < .031). There was no change in volume of late gadolinium enhancement at treatment. Patients who were untreated showed no change in any FDG PET or cardiac MRI parameter. CONCLUSION: Myocardial FDG uptake in patients suspected of having CS is presumed to represent active inflammation. When treated with corticosteroids, this resolved or regressed at follow-up, with an improvement in LVEF and FDG-avid thoracic disease. Patients who were untreated showed no change in any parameter. Quantification of FDG-avid myocardium using cardiac metabolic volume is proposed as a useful objective measure for assessing response to therapy.© RSNA, 2020See also commentary by Gutberlet in this issue.

Comparison of epicardial adipose tissue radiodensity threshold between contrast and non-contrast enhanced computed tomography scans: A cohort study of derivation and validation.

BACKGROUND AND AIMS: Epicardial adipose tissue (EAT) volume derived from contrast enhanced (CE) computed tomography (CT) scans is not well validated. We aim to establish a reliable threshold to accurately quantify EAT volume from CE datasets. METHODS: We analyzed EAT volume on paired non-contrast (NC) and CE datasets from 25 patients to derive appropriate Hounsfield (HU) cutpoints to equalize two EAT volume estimates. The gold standard threshold (-190HU, -30HU) was used to assess EAT volume on NC datasets. For CE datasets, EAT volumes were estimated using three previously reported thresholds: (-190HU, -30HU), (-190HU, -15HU), (-175HU, -15HU) and were analyzed by a semi-automated 3D Fat analysis software. Subsequently, we applied a threshold correction to (-190HU, -30HU) based on mean differences in radiodensity between NC and CE images (ΔEATrd = CE radiodensity - NC radiodensity). We then validated our findings on EAT threshold in 21 additional patients with paired CT datasets. RESULTS: EAT volume from CE datasets using previously published thresholds consistently underestimated EAT volume from NC dataset standard by a magnitude of 8.2%-19.1%. Using our corrected threshold (-190HU, -3HU) in CE datasets yielded statistically identical EAT volume to NC EAT volume in the validation cohort (186.1 ±â€¯80.3 vs. 185.5 ±â€¯80.1 cm3, Δ = 0.6 cm3, 0.3%, p = 0.374). CONCLUSIONS: Estimating EAT volume from contrast enhanced CT scans using a corrected threshold of -190HU, -3HU provided excellent agreement with EAT volume from non-contrast CT scans using a standard threshold of -190HU, -30HU.

Suppression of myocardial 18F-FDG uptake with a preparatory "Atkins-style" low-carbohydrate diet.

OBJECTIVES: Physiological myocardial uptake of 18F-FDG during positron emission tomography can mask adjacent abnormal uptake in mediastinal malignancy and inflammatory cardiac diseases. Myocardial uptake is unpredictable and variable. This study evaluates the impact of a low-carbohydrate diet in reducing myocardial FDG uptake. METHOD: Patients attending for clinically indicated oncological FDG PET were asked to have an "Atkins-style" low-carbohydrate diet (less than 3 g) the day before examination and an overnight fast. A total of 120 patients following low-carbohydrate diet plus overnight fast were compared with 120 patients prepared by overnight fast alone. Patients having an Atkins-style diet also completed a diet compliance questionnaire. SUV(max) and SUV(mean) for myocardium, blood pool and liver were measured in both groups. RESULTS: Myocardial SUV(max) fell from 3.53 ± 2.91 in controls to 1.77 ± 0.91 in the diet-compliant group. 98 % of diet-compliant patients had a myocardial SUV(max) less than 3.6 compared with 67 % of controls. Liver and blood pool SUV(max) rose from 2.68 ± 0.49 and 1.82 ± 0.30 in the control group to 3.14 ± 0.57 and 2.06 ± 0.30. CONCLUSION: An Atkins-style diet the day before PET, together with an overnight fast, effectively suppresses myocardial FDG uptake. KEY POINTS : • Low-carbohydrate diet (LCD) the day before PET suppresses myocardial FDG uptake. • LCD before PET increases liver and blood pool SUV ( max ) and SUV ( mean ). • Suppression of myocardial uptake may improve PET imaging of thoracic disease. • Suppression of myocardial uptake may help imaging cardiac inflammatory disease with PET.