Cardiac magnetic resonance imaging in heart failure: where the alphabet begins!

Cardiovascular Magnetic Resonance Demonstrates Myocardial Inflammation of Differing Etiologies and Acuities in Patients with Genetic and Inflammatory Myopathies

INTRODUCTION

Myopathies are heterogeneous neuromuscular diseases of genetic and/or inflammatory etiology that affect both cardiac and skeletal muscle. We investigated the prevalence of cardiac inflammation in patients with myopathies, cardiovascular symptoms, and normal echocardiography using cardiovascular magnetic resonance (CMR).

METHODS

We prospectively evaluated 51 patients with various genetic (n = 23) and inflammatory (n = 28) myopathies (median age, IQR: 12 (11-15) years, 22% girls; 61 (55-65) years, 46% women, respectively) and compared their CMR findings to corresponding age- and sex-matched controls (n = 21 and 20, respectively) and to each other.

RESULTS

Patients with genetic myopathy had similar biventricular morphology and function to healthy controls but showed higher late gadolinium enhancement (LGE), native T1 mapping, extracellular volume fraction (ECV), and T2 mapping values. Collectively, 22 (95.7%) patients with genetic myopathy had a positive T1-criterion and 3 (13.0%) had a positive T2-criterion according to the updated Lake Louise criteria. Compared with healthy controls, patients with inflammatory myopathy showed preserved left ventricular (LV) function and reduced LV mass, while all CMR-derived tissue characterization indices were significantly higher (p < 0.001 for all). All patients had a positive T1-criterion, and 27 (96.4%) had a positive T2-criterion. A positive T2-criterion or T2-mapping > 50 ms could discriminate between patients with genetic and inflammatory myopathies with a sensitivity of 96.4% and a specificity of 91.3% (AUC = 0.9557).

CONCLUSIONS

The vast majority of symptomatic patients with inflammatory myopathies and normal echocardiography show evidence of acute myocardial inflammation. In contrast, acute inflammation is rare in patients with genetic myopathies, who show evidence of chronic low-grade inflammation.

The Emerging Role of Combined Brain/Heart Magnetic Resonance Imaging for the Evaluation of Brain/Heart Interaction in Heart Failure

Heart failure (HF) patients frequently develop brain deficits that lead to cognitive dysfunction (CD), which may ultimately also affect survival. There is an important interaction between brain and heart that becomes crucial for survival in patients with HF. Our aim was to review the brain/heart interactions in HF and discuss the emerging role of combined brain/heart magnetic resonance imaging (MRI) evaluation. A scoping review of published literature was conducted in the PubMed EMBASE (OVID), Web of Science, Scopus and PsycInfo databases. Keywords for searches included heart failure, brain lesion, brain, cognitive, cognitive dysfunction, magnetic resonance imaging cardiovascular magnetic resonance imaging electroencephalogram, positron emission tomography and echocardiography. CD testing, the most commonly used diagnostic approach, can identify neither subclinical cases nor the pathophysiologic background of CD. A combined brain/heart MRI has the capability of diagnosing brain/heart lesions at an early stage and potentially facilitates treatment. Additionally, valuable information about edema, fibrosis and cardiac remodeling, provided with the use of cardiovascular magnetic resonance, can improve HF risk stratification and treatment modification. However, availability, familiarity with this modality and cost should be taken under consideration before final conclusions can be drawn. Abnormal CD testing in HF patients is a strong motivating factor for applying a combined brain/heart MRI to identify early brain/heart lesions and modify risk stratification accordingly.

Diagnosis of cardiac sarcoidosis: a primer for non-imagers

Sarcoidosis is a multisystem granulomatous disorder that can potentially involve any organ. Cardiac involvement in sarcoidosis has been reported in up to 25% of patients based on autopsy and imaging studies. The gold standard for diagnosing cardiac sarcoidosis is endomyocardial biopsy demonstrating non-caseating granulomas; however, this technique lacks sensitivity due to the patchy nature of myocardial involvement. This, along with the non-specific clinical presentation, renders the diagnosis of cardiac sarcoidosis extremely challenging. Difficulties in obtaining histopathologic diagnosis and the advances in imaging modalities have led to a paradigm shift toward non-invasive imaging in the diagnosis of cardiac sarcoidosis. Advances in cardiac imaging modalities have also allowed unprecedented insights into the prevalence and natural history of cardiac sarcoidosis. This review discusses the role of non-invasive imaging for diagnosis, risk stratification, and monitoring the response to therapies in cardiac sarcoidosis. Echocardiography remains the first-line modality due to widespread availability and affordability. Cardiac magnetic resonance imaging (CMR) can be used to study cardiac structure, function, and most importantly tissue characterization to detect inflammation and fibrosis. Fluoro-deoxy glucose positron emission tomography (FDG PET) is the gold standard for non-invasive detection of cardiac inflammation, and it offers the unique ability to assess response to therapeutic interventions. Hybrid imaging is a promising technique that allows us to combine the unique strengths of CMR and FDG PET. Understanding the advantages and disadvantages of each of these imaging modalities is crucial in order to tailor the diagnostic algorithm and utilize the most appropriate modality for each patient.

Role of Cardiac Magnetic Resonance Imaging in Heart Failure

This review describes the current role and potential future applications of cardiac magnetic resonance (CMR) for the management of heart failure (HF). CMR allows noninvasive morphologic and functional assessment, tissue characterization, blood flow, and perfusion evaluation. CMR overcomes echocardiography limitations (geometric assumptions, interobserver variability and poor acoustic window) and provides incremental information in relation to cause, prognosis, and treatment monitoring of patients with HF.

Detection of Left Ventricular Thrombi on Cardiac Magnetic Resonance Viability Studies

Objective

To highlight detection of left ventricular thrombi on cardiac magnetic resonance (CMR) viability studies.

Method

This retrospective observational study was conducted in the Radiology Department at our Hospital in Dhahran, from April 2015-2019. All recently re-perfused (post-percutaneous coronary intervention/PCI) patients with ST-segment elevation myocardial infarctions (STEMI), having low ejection fractions (<40%), impaired LV functions or abnormal wall motions on transthoracic echocardiographies (TTEs), who underwent cardiac magnetic resonance (CMR) imaging viability studies were included. Patients with incomplete or limited studies (due to artifacts), previous coronary artery bypass graft (CABG), those who lost follow-ups, and those who were contraindicated or unfit for MRIs were excluded. An area of low signal intensity with no late gadolinium enhancement (LGE) was defined as thrombus on MR imaging, and two radiologists reached consensus report for the diagnoses. Patients with anterior or non-anterior wall MI were documented, and their ejection fractions were recorded. Percentage estimation of LV thrombi as detected on CMR studies was made. Any complications (like MI, stroke or death) that occurred within one year of diagnoses were documented. A Chi-square was used to determine association.

Results

Of the 125 patients, most were men (71.2%) with a mean age of 56.78 years. Eleven patients had left ventricular thrombi (8.8%), and most of these were anterior wall infarctions with low ejection fractions (<40%). Three out of 11 patients with LV thrombi developed complications versus 3 out of 114 without LV thrombi (P- value, .0005).

Conclusion

Left ventricular thrombi can be detected on cardiac viability studies in recently re-perfused STEMI patients and may possibly predict the risk of complications.

The role of cardiac imaging in the management of non-ischemic cardiovascular diseases in human immunodeficiency virus infection

Infection with human immunodeficiency virus (HIV) has become the pandemic of the new century. About 36.9 million people are living with HIV worldwide. The introduction of antiretroviral therapy in 1996 has dramatically changed the global landscape of HIV care, resulting in significantly improved survival and changing HIV to a chronic disease. With near-normal life expectancy, contemporary cardiac care faces multiple challenges of cardiovascular diseases, disorders specific to HIV/AIDS, and those related to aging and higher prevalence of traditional risk factors. Non-ischemic cardiovascular diseases are major components of cardiovascular morbidity and mortality in HIV/AIDS. Non-invasive cardiac imaging plays a pivotal role in the management of these diseases. This review summarizes the non-ischemic presentation of the HIV cardiovascular spectrum focusing on the role of cardiac imaging in the management of these disorders.

Comparison Between 3D Echocardiography and Cardiac Magnetic Resonance Imaging (CMRI) in the Measurement of Left Ventricular Volumes and Ejection Fraction

BACKGROUND

Echocardiography and Cardiac Magnetic Resonance Imaging (CMRI) are two noninvasive techniques for the evaluation of cardiac function for patients with coronary artery diseases. Although echocardiography is the commonly used technique in clinical practice for the assessment of cardiac function, the measurement of LV volumes and left ventricular ejection fraction (LVEF) by the use of this technique is still influenced by several factors inherent to the protocol acquisition, which may affect the accuracy of echocardiography in the measurement of global LV parameters.

OBJECTIVE

The aim of this study is to compare the end systolic volume (ESV), the end diastolic volume (EDV), and the LVEF values obtained with three dimensional echocardiography (3D echo) with those obtained by CMRI (3 Tesla) in order to estimate the accuracy of 3D echo in the assessment of cardiac function.

METHODS

20 subjects, (9 controls, 6 with myocardial infarction, and 5 with myocarditis) with age varying from 18 to 58, underwent 3D echo and CMRI. LV volumes and LVEF were computed from CMRI using a stack of cine MRI images in a short axis view. The same parameters were calculated using the 3D echo. A linear regression analysis and Bland Altman diagrams were performed to evaluate the correlation and the degree of agreement between the measurements obtained by the two methods.

RESULTS

The obtained results show a strong correlation between the 3D echo and CMR in the measurement of functional parameters (r = 0.96 for LVEF values, r = 0.99 for ESV and r= 0.98 for EDV, p < 0.01 for all) with a little lower values of LV volumes and higher values of LVEF by 3D echo compared to CMRI. According to statistical analysis, there is a slight discrepancy between the measurements obtained by the two methods.

CONCLUSION

3D echo represents an accurate noninvasive tool for the assessment of cardiac function. However, other studies should be conducted on a larger population including some complicated diagnostic cases.

Left Ventricular Function and Myocardial Triglyceride Content on 3T Cardiac MR Predict Major Cardiovascular Adverse Events and Readmission in Patients Hospitalized with Acute Heart Failure

Background: This prospective study was designed to investigate whether myocardial triglyceride (TG) content from proton magnetic resonance spectroscopy (MRS) and left ventricular (LV) function parameters from cardiovascular magnetic resonance imaging (CMR) can serve as imaging biomarkers in predicting future major cardiovascular adverse events (MACE) and readmission in patients who had been hospitalized for acute heart failure (HF). Methods: Patients who were discharged after hospitalization for acute HF were prospectively enrolled. On a 3.0 T MR scanner, myocardial TG contents were measured using MRS, and LV parameters (function and mass) were evaluated using cine. The occurrence of MACE and the HF-related readmission served as the endpoints. Independent predictors were identified using univariate and multivariable Cox proportional hazard regression analyses. Results: A total of 133 patients (mean age, 52.4 years) were enrolled. The mean duration of follow-up in surviving patients was 775 days. Baseline LV functional parameters—including ejection fraction, LV end-diastolic volume, LV end-diastolic volume index (LVEDVI), and LV end-systolic volume (p < 0.0001 for all), and myocardial mass (p = 0.010)—were significantly associated with MACE. Multivariable analysis revealed that LVEDVI was the independent predictor for MACE, while myocardial mass was the independent predictor for 3- and 12-month readmission. Myocardial TG content (lipid resonances δ 1.6 ppm) was significantly associated with readmission in patients with ischemic heart disease. Conclusions: LVEDVI and myocardial mass are potential imaging biomarkers that independently predict MACE and readmission, respectively, in patients discharged after hospitalization for acute HF. Myocardial TG predicts readmission in patients with a history of ischemic heart disease.

Right Heart-Pulmonary Circulation Unit in Congenital Heart Diseases

The right ventricle plays a major role in congenital heart disease. This article describes the right ventricular mechanics in some selected congenital heart diseases affecting the right ventricle in different ways: tetralogy of Fallot, Ebstein anomaly, and the systemic right ventricle.

Antimalarial-induced Cardiomyopathy in Systemic Lupus Erythematosus: As Rare as Considered?

OBJECTIVE

Antimalarials (AM) are recommended for all systemic lupus erythematosus (SLE) patients without specific contraindications. Their main adverse effect is retinal damage; however, heart disease has been described in isolated cases. The aim of our study is to describe 8 patients with AM-induced cardiomyopathy (AMIC) in a defined SLE cohort.

METHODS

Patients attending the Toronto Lupus Clinic and diagnosed with definite (based on endomyocardial biopsy; EMB) and possible AMIC were included [based on cardiac magnetic resonance imaging (cMRI) and other investigations].

RESULTS

Eight female patients (median age 62.5 yrs, disease duration 35 yrs, AM use duration 22 yrs) were diagnosed with AMIC in the past 2 years. Diagnosis was based on EMB in 3 (extensive cardiomyocyte vacuolation, intracytoplasmic myelinoid, and curvilinear bodies). In 4 patients, cMRI was highly suggestive of AMIC (ventricular hypertrophy and/or atrial enlargement and late gadolinium enhancement in a nonvascular pattern). Another patient was diagnosed with complete atrioventricular block, left ventricular and septal hypertrophy, along with concomitant ocular toxicity. All patients had abnormal cardiac troponin I (cTnI) and brain natriuretic peptide (BNP), whereas 7/8 also had chronically elevated creatine phosphokinase. During followup, 1 patient died from refractory heart failure. In the remaining patients, hypertrophy regression and a steady decrease of heart biomarkers were observed after AM cessation.

CONCLUSION

Once considered extremely rare, AMIC seems to be underrecognized, probably because of the false attribution of heart failure or hypertrophy to other causes. Certain biomarkers (cTnI, BNP) and imaging findings may lead to early diagnosis and enhance survival.

Accuracy of cardiac magnetic resonance imaging to rule out significant coronary artery disease in patients with systolic heart failure of unknown aetiology: Single-centre experience and comprehensive meta-analysis

BACKGROUND

Coronary artery disease (CAD) is the leading cause of systolic heart failure (HF). Cardiac magnetic resonance imaging (CMR) is a non-invasive technique that detects a myocardial infarction scar as subendocardial or transmural late gadolinium enhancement (st-LGE).

AIM

We sought to evaluate whether a lack of st-LGE could rule out CAD in new-onset systolic HF of unknown aetiology.

METHODS

We included 232 consecutive patients with new-onset HF and left ventricular ejection fraction ≤35% who underwent both coronary angiography and CMR to assess HF aetiology. CAD was defined as the presence of coronary artery stenosis≥50% on a coronary angiogram. We assessed sensitivity, specificity, and positive and negative likelihood ratios (PLR and NLR) of the presence of st-LGE to detect underlying CAD. A complementary meta-analysis of 11 studies (including ours) was also performed.

RESULTS

In our study, 49 (21.1%) patients had CAD. The sensitivity and specificity of the presence of st-LGE to detect CAD were 69 and 92%, respectively. PLR and NLR were 8.47 and 0.33, respectively. In the meta-analysis, 1227 patients were included, and the prevalence of CAD ranged from 19.2 to 68.3%. Sensitivity, specificity, PLR and NLR were 87% (95% confidence interval [CI] 0.80-0.92), 93% (95% CI 0.89-0.96), 12.91 (95% CI 7.70-21.64) and 0.14 (95% CI 0.09-0.22), respectively. Altogether, 55 patients presented CAD with no st-LGE; inversely, 75 patients presented st-LGE with no CAD.

CONCLUSION

With a CMR specificity of 93%, the absence of st-LGE rules out significant underlying CAD in patients with systolic HF of unknown aetiology in most cases.

Cardiorespiratory Fitness and Cardiovascular Disease Prevention: an Update

PURPOSE OF REVIEW

Cardiovascular diseases account for nearly one third of all deaths globally. Improving exercise capacity and cardiorespiratory fitness (CRF) has been an important target to reduce cardiovascular events. In addition, the American Heart Association defined decreased physical activity as the fourth risk factor for coronary artery disease. Multiple large cohort studies have evaluated the impact of CRF on outcomes. In this review, we will discuss the role of CRF in reducing cardiovascular morbidity and mortality.

RECENT FINDINGS

Recent data suggest that CRF has an important role in reducing not only cardiovascular and all-cause mortality, but also incident myocardial infarction, hypertension, diabetes, atrial fibrillation, heart failure, and stroke. Most recently, its role in cancer prevention started to emerge. CRF protective effects have also been seen in patients with prior comorbidities like prior coronary artery disease, heart failure, depression, end-stage renal disease, and stroke. The prognostic value of CRF has been demonstrated in various patient populations and cardiovascular conditions. Higher CRF is associated with improved survival and decreased incidence of cardiovascular diseases (CVD) and other comorbidities including hypertension, diabetes, heart failure, and atrial fibrillation.

Multimodality Imaging of Pericardial Diseases

OPINION STATEMENT

Pericardial diseases have changed their epidemiology in the past few years. With the aging population and decreasing incidence of communicable diseases, the causes of pericardial diseases have significantly changed from infectious and malignant to postradiation and cardiac surgery causes. Despite that, pericardial diseases remain difficult to diagnose. The accurate and timely diagnosis of these diseases is essential to avoid the late sequela of pericardial constriction and pericardial cirrhosis. Echocardiography remains the first test of choice for the assessment of patients with suspected pericardial diseases. Most patients with acute pericarditis have a self-limiting course and do not need further imaging. However, in the era of multimodality imaging, other modalities, namely, computed tomography (CT) and magnetic resonance imaging (CMR), are often utilized in complex cases. These two modalities provide a wide-open view of the pericardium and adjacent structures. They have high resolution to assess pericardial calcification, a hallmark of many diseases especially tuberculous constrictive pericarditis. CMR is also unique in its ability to assess pericardial late gadolinium enhancement (LGE) and edema. These have been recently suggested to be very important in the progression from acute pericarditis to constrictive pericarditis. In addition, they provide prognostic value to assess which patients are at high risk of developing heart failure and resource utilization. Thus, in the current era, patients with suspected complex pericardial diseases will need a multimodality approach rather than a single modality approach.