Cardiac magnetic resonance assessment of diastolic dysfunction in acute coronary syndrome

Chest pain is an important presenting symptom. However, few cases of chest pain are diagnosed as acute coronary syndrome (ACS) in the acute setting. This results in frequent inappropriate discharge and major delay in treatment for patients with underlying ACS. The conventional methods of assessing ACS, which include electrocardiography and serological markers of infarct, can take time to manifest. Recent studies have investigated more sensitive and specific imaging modalities that can be used. Diastolic dysfunction occurs early following coronary artery occlusion and its detection is useful in confirming the diagnosis, risk stratification, and prognosis post-ACS. Cardiac magnetic resonance provides a single imaging modality for comprehensive evaluation of chest pain in the acute setting. In particular, cardiac magnetic resonance has many imaging techniques that assess diastolic dysfunction post-coronary artery occlusion. Techniques such as measurement of left atrial size, mitral inflow, and mitral annular and pulmonary vein flow velocities with phase-contrast imaging enable general assessment of ventricular diastolic function. More novel imaging techniques, such as T2-weighted imaging for oedema, T1 mapping, and myocardial tagging, allow early determination of regional diastolic dysfunction and oedema. These findings may correspond to specific infarcted arteries that may be used to tailor eventual percutaneous coronary artery intervention

Paclitaxel-eluting balloon and everolimus-eluting stent for provisional stenting of coronary bifurcations: 12-month results of the multicenter BIOLUX-I study

Background: Several studies investigated the combination of bare metal stents in the main branch and drug-eluting balloons in the side branch in bifurcation lesions, but data on the combination of drug-eluting stents and drug-eluting balloons are scarce. We aim to assess the feasibility of provisional stenting with an everolimus-eluting stent in the main branch and a paclitaxel-eluting balloon in the side branch. Methods: In this prospective, multi-center study conducted in 5 Australian sites, 35 patients with bifurcation lesions were enrolled. Angiographic and intravascular ultrasound assessments were conducted at 9. months; clinical follow-up was conducted until 12. months. Results: The primary endpoint, late lumen loss in the side branch measured by quantitative coronary angiography, was 0.10 ± 0.43. mm. No binary restenosis was observed. One patient died; 3 myocardial infarctions (one suspected and two in non-target vessels) and one target lesion revascularization occurred. No probable or definite stent thrombosis was observed. Conclusion: The combination of an everolimus-eluting stent in the main branch and a paclitaxel-eluting balloon in the side branch appears to be a safe, effective and novel treatment option for bifurcation lesions

Enter evaluation of mitral inflow velocity profile: optimal through plane location for mitral inflow assessment with cardiac magnetic resonance

Diastology is usually assessed using transthoracic echocardiography (TTE). Velocity‐encoded phase‐contrast imaging permits evaluation with cardiac magnetic resonance (CMR). Heterogeneous contour locations have been used to measure mitral (MV) inflow velocities and the optimal contour location is uncertain. We evaluated CMR MV inflow velocities against TTE to identify the optimal location

Validation of cardiovascular magnetic resonance assessment of pericardial adipose tissue volume

© 2009 Nelson et al; licensee BioMed Central Ltd.Background Pericardial adipose tissue (PAT) has been shown to be an independent predictor of coronary artery disease. To date its assessment has been restricted to the use of surrogate echocardiographic indices such as measurement of epicardial fat thickness over the right ventricular free wall, which have limitations. Cardiovascular magnetic resonance (CMR) offers the potential to non-invasively assess total PAT, however like other imaging modalities, CMR has not yet been validated for this purpose. Thus, we sought to describe a novel technique for assessing total PAT with validation in an ovine model. Methods 11 merino sheep were studied. A standard clinical series of ventricular short axis CMR images (1.5T Siemens Sonata) were obtained during mechanical ventilation breath-holds. Beginning at the mitral annulus, consecutive end-diastolic ventricular images were used to determine the area and volume of epicardial, paracardial and pericardial adipose tissue. In addition adipose thickness was measured at the right ventricular free wall. Following euthanasia, the paracardial adipose tissue was removed from the ventricle and weighed to allow comparison with corresponding CMR measurements. Results There was a strong correlation between CMR-derived paracardial adipose tissue volume and ex vivo paracardial mass (R2 = 0.89, p < 0.001). In contrast, CMR measurements of corresponding RV free wall paracardial adipose thickness did not correlate with ex vivo paracardial mass (R2 = 0.003, p = 0.878). Conclusion In this ovine model, CMR-derived paracardial adipose tissue volume, but not the corresponding and conventional measure of paracardial adipose thickness over the RV free wall, accurately reflected paracardial adipose tissue mass. This study validates for the first time, the use of clinically utilised CMR sequences for the accurate and reproducible assessment of pericardial adiposity. Furthermore this non-invasive modality does not use ionising radiation and therefore is ideally suited for future studies of PAT and its role in cardiovascular risk prediction and disease in clinical practiceAdam J Nelson, Matthew I Worthley, Peter J Psaltis, Angelo Carbone, Benjamin K Dundon, Rae F Duncan, Cynthia Piantadosi, Dennis H Lau, Prashanthan Sanders, Gary A Wittert and Stephen G Worthle

Diagnostic Accuracy of Adenosine Stress Cardiovascular Magnetic Resonance Following Acute ST-segment Elevation Myocardial Infarction Post Primary Angioplasty

Extent: 8p.Background: Adenosine stress cardiovascular magnetic resonance (CMR) has been proven an effective tool in detection of reversible ischemia. Limited evidence is available regarding its accuracy in the setting of acute coronary syndromes, particularly in evaluating the significance of non-culprit vessel ischaemia. Adenosine stress CMR and recent advances in semi-quantitative image analysis may prove effective in this area. We sought to determine the diagnostic accuracy of semi-quantitative versus visual assessment of adenosine stress CMR in detecting ischemia in non-culprit territory vessels early after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methods: Patients were prospectively enrolled in a CMR imaging protocol with rest and adenosine stress perfusion, viability and cardiac functional assessment 3 days after successful primary-PCI for STEMI. Three short axis slices each divided into 6 segments on first pass adenosine perfusion were visually and semi-quantitatively analysed. Diagnostic accuracy of both methods was compared with non-culprit territory vessels utilising quantitative coronary angiography (QCA) with significant stenosis defined as ≥70%. Results: Fifty patients (age 59 ± 12 years) admitted with STEMI were evaluated. All subjects tolerated the adenosine stress CMR imaging protocol with no significant complications. The cohort consisted of 41% anterior and 59% non anterior infarctions. There were a total of 100 non-culprit territory vessels, identified on QCA. The diagnostic accuracy of semi-quantitative analysis was 96% with sensitivity of 99%, specificity of 67%, positive predictive value (PPV) of 97% and negative predictive value (NPV) of 86%. Visual analysis had a diagnostic accuracy of 93% with sensitivity of 96%, specificity of 50%, PPV of 97% and NPV of 43%. Conclusion: Adenosine stress CMR allows accurate detection of non-culprit territory stenosis in patients successfully treated with primary-PCI post STEMI. Semi-quantitative analysis may be required for improved accuracy. Larger studies are however required to demonstrate that early detection of non-culprit vessel ischemia in the post STEMI setting provides a meaningful test to guide clinical decision making and ultimately improved patient outcomes.Dennis TL Wong, Michael CH Leung, Rajiv Das, Gary YH Liew, Kerry Williams, Benjamin K Dundon, Payman Molaee, Karen SL Teo, Ian T Meredith, Matthew I Worthley and Stephen G Worthle