Role of Imaging in Evaluating Infiltrative Heart Disease

3-Tesla cardiac magnetic resonance imaging in primary dilated cardiomyopathy

Background

Cardiac magnetic resonance imaging (CMR) is an excellent non-invasive imaging tool in the assessment of patients with dilated cardiomyopathy (DCM). Few studies have analysed the findings in primary (idiopathic) DCM.

Objectives

To study the CMR features in primary DCM.

Methods

We conducted a descriptive observational study on 20 adult patients with suspected or confirmed primary DCM. Each patient underwent a dedicated 3-Tesla CMR scan, and the findings were evaluated.

Results

Seventeen patients had systolic dysfunction with a reduced ejection fraction and elevated end-diastolic volume, 19 patients had contractile dysfunction in the form of global left ventricular hypokinesia, 13 patients showed no abnormal delayed contrast enhancement with gadolinium administration, and 7 patients showed abnormal late gadolinium enhancement patterns.

Conclusion

In patients with primary DCM, CMR is a powerful diagnostic tool that can definitively establish the diagnosis, assess the severity of the disease, predict the risk of future adverse cardiovascular outcomes, check for complications, and assist in future follow-ups.

Study synopsis

What the study adds. Cardiac magnetic resonance imaging (CMR) is an excellent non-invasive imaging tool in the assessment of patients with primary dilated cardiomyopathy (DCM). Findings include global ventricular enlargement, systolic dysfunction (ejection fraction <40%), and elevated end-diastolic (≥140 mL) and end-systolic volumes. Global abnormal wall contractility is often seen. In DCM there is either no abnormal gadolinium enhancement or curvilinear mid-myocardial or subepicardial late gadolinium enhancement, unrelated to a coronary artery distribution.Implications of the findings. In patients with primary DCM, CMR provides powerful diagnostic and prognostic information. Enhanced awareness and understanding of this relatively uncommon condition among clinicians and radiologists would be of benefit in patient management and treatment.

Same day comparison of PET/CT and PET/MR in patients with cardiac sarcoidosis

BACKGROUND

Inflammatory cardiac disorders, in particular, sarcoidosis, play an important role in left ventricular dysfunction, conduction abnormalities, and arrhythmias. In this study, we compared the imaging characteristics and diagnostic information obtained when patients were imaged sequentially with PET/CT and then with hybrid PET/MRI on the same day following a single 18F-FDG injection.

METHODS

Ten patients with known or suspected sarcoidosis underwent imaging in sequence of (a) 99mTc-MIBI, (b) 18F-FDG with PET/CT, and (c) 18F-FDG with 3T PET/MRI. Images were compared quantitatively by determination of SUVmax and SUV on a voxel by voxel basis, and qualitatively by two experienced observers.

RESULTS

When both platforms were compared quantitatively, similar data for the evaluation of enhanced 18F-FDG uptake were obtained. Qualitatively, there were (1) several instances of normal perfusion with delayed enhancement and/or focal 18F-FDG uptake, (2) comparable enhanced 18F-FDG uptake on PET/CT vs. PET/MRI, and (3) diversity in disease patterns with delayed enhancement only, increased 18F-FDG uptake only, or both.

CONCLUSION

In this limited patient study, PET/CT and PET/MR provided similar diagnostic data for 18F-FDG uptake, and the concurrent acquisition of MR images provided further insight into the disease process.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness. Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent ^99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening. Results: Five patients (4%; 95%CI:0-7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0-4%) had CD and 3 (11%; 95%CI:0-23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died. Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.