Multi-parametric non-contrast cardiac magnetic resonance for the differentiation between cardiac amyloidosis and hypertrophic cardiomyopathy.

AIM: To evaluate the ability of fast strain-encoded (SENC) cardiac magnetic resonance (CMR) derived myocardial strain and native T1 mapping to discriminate between hypertrophic cardiomyopathy (HCM) and cardiac amyloidosis. METHODS: Ninety nine patients (57 with hypertrophic cardiomyopathy and 42 with cardiac amyloidosis) were systematically analysed. LV-ejection fraction, LV-mass index, septal wall thickness and native T1 mapping values were assessed. In addition, global circumferential and longitudinal strain and segmental circumferential and longitudinal strain in basal, mid-ventricular, and apical segments were calculated. A ratio was built by dividing native T1 values by basal segmental strain (T1-to-basal segmental strain ratio). RESULTS: Myocardial strain was equally distributed in apical and basal segments in HCM patients, whereas an apical sparing with less impaired apical strain was noticed in cardiac amyloidosis (apical-to-basal-ratio of 1.01 ± 0.23 versus 1.20 ± 0.28, p < 0.001). T1 values were significantly higher in amyloidosis compared to HCM patients (1170.7 ± 66.4 ms versus 1078.3 ± 57.4ms, p < 0.001). The T1-to-basal segmental strain ratio exhibited high accuracy for the differentiation between the two clinical entities (Sensitivity = 85%, Specificity = 77%, AUC = 0.90, 95% CI = 0.81-0.95, p < 0.001). Multivariable analysis showed that age and the T1-to-basal-strain-ratio were the most robust factors for the differentiation between HCM and cardiac amyloidosis. CONCLUSION: The T1-to-basal-segmental strain ratio, combining information from segmental circumferential and longitudinal strain and native T1 mapping aids the differentiation between HCM and cardiac amyloidosis with high accuracy and within a fast CMR protocol, obviating the need for contrast agent administration.

Cardiovascular magnetic resonance for the evaluation of patients with cardiovascular disease: An overview of current indications, limitations, and procedures.

Cardiovascular disease (CVD) is the most common cause of morbidity/mortality worldwide. Early diagnosis is the key to improve CVD prognosis, and cardiovascular imaging plays a crucial role in this direction. Echocardiography is the most commonly used imaging modality. However, the need for early diagnosis/treatment favors the development of modalities providing information about tissue characterization beyond echocardiography. In this context, the rapid evolution of cardiovascular magnetic resonance (CMR) led to the coexistence of cardiologists and radiologists in the CMR field. Our aim was to provide an overview of indications, sequences, and reporting of CMR findings in various CVDs. The indications/limitations of CMR as well as the pathophysiological significance of various sequences in adult/pediatric CVDs are presented and discussed in detail. The role of CMR indices in the evaluation of the most common clinical scenarios in cardiology and their impact on CVD diagnosis/prognosis were analyzed in detail. Additionally, the comparison of CMR versus other imaging modalities is also discussed. Finally, future research directions are presented. CMR can provide cardiac tissue characterization and biventricular/biatrial functional assessment in the same examination, allowing for early and accurate identification of important subclinical abnormalities, before clinically overt CVD takes place.

Role of cardiac CT in the diagnostic evaluation and risk stratification of patients with myocardial infarction and non-obstructive coronary arteries (MINOCA): rationale and design of the MINOCA-GR study.

INTRODUCTION: Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in 5%-15% of all patients with acute myocardial infarction. Cardiac MR (CMR) and optical coherence tomography have been used to identify the underlying pathophysiological mechanism in MINOCA. The role of cardiac CT angiography (CCTA) in patients with MINOCA, however, has not been well studied so far. CCTA can be used to assess atherosclerotic plaque volume, vulnerable plaque characteristics as well as pericoronary fat tissue attenuation, which has not been yet studied in MINOCA. METHODS AND ANALYSIS: MINOCA-GR is a prospective, multicentre, observational cohort study based on a national registry that will use CCTA in combination with CMR and invasive coronary angiography (ICA) to evaluate the extent and characteristics of coronary atherosclerosis and its correlation with pericoronary fat attenuation in patients with MINOCA. A total of 60 consecutive adult patients across 4 participating study sites are expected to be enrolled. Following ICA and CMR, patients will undergo CCTA during index hospitalisation. The primary endpoints are quantification of extent and severity of coronary atherosclerosis, description of high-risk plaque features and attenuation profiling of pericoronary fat tissue around all three major epicardial coronary arteries in relation to CMR. Follow-up CCTA for the evaluation of changes in pericoronary fat attenuation will also be performed. MINOCA-GR aims to be the first study to explore the role of CCTA in combination with CMR and ICA in the underlying pathophysiological mechanisms and assisting in diagnostic evaluation and prognosis of patients with MINOCA. ETHICS AND DISSEMINATION: The study protocol has been approved by the institutional review board/independent ethics committee at each site prior to study commencement. All patients will provide written informed consent. Results will be disseminated at national meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT4186676.

The Interplay between Myocardial Fibrosis, Strain Imaging and Collagen Biomarkers in Adults with Repaired Tetralogy of Fallot.

BACKGROUND: We sought to assess the interplay between right ventricle (RV) fibrosis, biventricular dysfunction based on global longitudinal strain (GLS) analysis, and biomarkers such as Galectin-3 (Gal-3), procollagen type III (PCIII), and NTproBNP. METHODS: We studied 35 adult patients with rToF. All patients underwent a cardiac magnetic resonance (CMR) scan including feature tracking for deformation imaging. Blood biomarkers were measured. RESULTS: LGE RV was detected in all patients, mainly at surgical sites. Patients with the highest RV LGE scoring had greater RV dilatation and dysfunction whereas left ventricular (LV) function was preserved. LV GLS correlated with RV total fibrosis score (p = 0.007). A LV GLS value of -15.9% predicted LGE RV score > 8 (AUC 0.754 (p = 0.02)). Neither RV GLS nor biomarker levels were correlated with the extent of RV fibrosis. A cut-off value for NTproBNP of 145.25 pg/mL predicted LGE RV score > 8 points (AUC 0.729, (p = 0.03)). A cut-off value for Gal-3 of 7.42 ng/mL predicted PR Fraction > 20% [AUC 0.704, (p = 0.05)]. CONCLUSIONS: A significant extent of RV fibrosis was mainly detected at surgical sites of RV, affecting RV performance. CMR-FT reveals subtle LV dysfunction in rToF patients, due to decreased performance of the fibrotic RV. Impaired LV function and elevated NTproBNP in rToF reflect a dysfunctional fibrotic RV.

Endovascular management of subclavian-steal syndrome in a patient with post-traumatic dissection of an aberrant right subclavian artery.

BACKGROUND: An aberrant right subclavian artery is the most common congenital anomaly of the aortic arch and may cause symptoms due to aneurysmal dilatation, stenosis or occlusion. We present a case of subclavian-steal syndrome due to post-traumatic dissection of an aberrant right subclavian artery. METHODS AND RESULTS: A 50 year-old man presented with dizziness and fainting episodes after exercising his right arm and a systolic blood pressure gradient of 40 mm Hg between the 2 arms. Suspecting a subclavian steal syndrome, a computed tomography angiography was requested which revealed an aberrant right subclavian artery with a severe stenosis proximal to the ostium of the vertebral artery. Transfemoral digital subtraction angiography showed a local dissection of the aberrant right subclavian artery with late retrograde filling of the ipsilateral vertebral artery. The lesion was successfully treated with primary stent implantation (9 mm x 40 mm, LIFESTAR, BARD). On interrogation, the patient recalled an injury to the right arm after falling off a ladder 10 years earlier, as a possible post-traumatic cause for the dissection. He had an uneventful outcome and is symptom-free 12 months down the line. CONCLUSIONS: The combination of post-traumatic dissection of an aberrant right subclavian artery resulting to subclavian steal syndrome is an extremely rare scenario. Endovascular management is a safe, minimally invasive alternative to open surgery.

Duration of interventricular septal shift toward the left ventricle is associated with poor clinical outcome in precapillary pulmonary hypertension: A cardiac magnetic resonance study.

BACKGROUND: Right ventricular pressure overload results in interventricular septal shift toward the left ventricle in patients with precapillary pulmonary hypertension (PH). We aimed to investigate the predictive role of the duration of septal curvature configuration during the cardiac cycle, as expressed by the novel marker curvature duration index (CDi) in precapillary PH. METHODS: This was a prospective study. All patients underwent cardiac magnetic resonance (CMR). CDi was defined by the number of CMR frames in which septal curvature configuration toward left ventricle is observed *100/total number of frames per cardiac cycle. Time from enrollment to first clinical failure event (death, hospitalization due to PH, and disease progression) was recorded. RESULTS: The study included 36 patients with precapillary PH. During a median follow-up of 20 months (IQR 4-37 months), 14 clinical failure events were observed. Survival ROC analysis showed that the optimal cutoff value of CDi, which predicted clinical failure, was 67%. Kaplan-Meier survival analysis showed that CDi≥67% was associated with a 9.4-fold increase in the risk for clinical failure. Addition of CDi to baseline models including six-minute walk test distance (c-statistic = 0.65 vs. c-statistic = 0.79), NT-proBNP (c-statistic = 0.72 vs. c-statistic = 0.83), and WHO functional class (c-statistic = 0.76 vs. c-statistic = 0.81) improved risk stratification. CONCLUSION: Ventricular septal shift toward the left ventricle lasting for more than the two thirds of the cardiac cycle is associated with worse prognosis in precapillary PH.

Right Atrial Function Predicts Clinical Outcome in Patients with Precapillary Pulmonary Hypertension.

BACKGROUND: Although the primary role of right atrial (RA) size in the diagnosis and risk stratification of precapillary pulmonary hypertension (PH) has been studied, little is known about the clinical significance of RA function. In line with studies assessing left atrial function in heart failure, the aim of this study was to introduce the RA function index (RAFi) and to explore its prognostic power in precapillary PH. METHODS: RA emptying fraction was calculated as (RA end-systolic volume - RA end-diastolic volume) × 100/(RA end-systolic volume). RAFi was calculated as (RA emptying fraction × right ventricular outflow tract velocity-time integral)/(RA end-systolic volume index). Patients were followed for the end point of clinical failure, which was defined as death, hospitalization because of PH, or disease progression. RESULTS: In total, 47 patients with precapillary PH were included. Mean RAFi was 16.1 ± 22.3%. Over a median follow-up period of 25 months (interquartile range, 9.5-41.1 months), 29 patients experienced clinical failure. Univariate Cox proportional-hazard analysis showed that RAFi was a predictor of clinical failure (hazard ratio, 0.935; 95% CI, 0.890-0.981; P = .007). Addition of RAFi to established predictors of outcomes, including 6-minute walk distance, N-terminal pro-B-type natriuretic peptide, and RA area, improved their prognostic power. CONCLUSIONS: RAFi is an easily assessed echocardiographic parameter, which is strongly predictive of clinical outcomes in patients with precapillary PH. Further studies are needed to validate RAFi and define its role in clinical practice.

Thin isotropic FLAIR MR images at 1.5T increase the yield of focal cortical dysplasia transmantle sign detection in frontal lobe epilepsy.

OBJECTIVE: The transmantle sign is a distinctive imaging marker of focal cortical dysplasia (FCD) type II in frontal lobe epilepsy (FLE), which is revealed predominantly by fluid-attenuation inversion recovery (FLAIR) sequences. Although the transmantle sign detection yield is high by routine imaging protocols for epilepsy at 3T, most centers around the world have access to 1.5T MR technology and FLE patients often receive negative imaging reports. This study investigates the optimization of transmantle detection yield at 1.5T by introducing a 3D thin-slice isotropic FLAIR sequence in the epilepsy imaging protocol. METHODS: Twenty FLE patients underwent diagnostic imaging for epilepsy with typical 2D thick-slice (3.0mm) coronal FLAIR sequences and a 3D thin-slice (1.0mm) isotropic FLAIR sequences at 1.5T, and transmantle sign detection yields and thickness measurements were derived. RESULTS: The 2D thick-slice FLAIR detected a transmantle sign in seven (35.0%) patients. The 3D isotropic thin-slice FLAIR detected a transmantle sign in eleven (55.0%) patients, thereby increasing the transmantle sign detection yield by 57.4%. The mean transmantle sign thickness by thick images was 12.3mm, by thin images was 8.9mm, and in the patients undetected by thick FLAIR was 3.5mm. SIGNIFICANCE: This study showed that the extratemporal transmantle sign in FLE patients can be thin enough to be missed by thick-slice FLAIR sequences at 1.5T. By introducing 3D thin-slice isotropic FLAIR, false-negative reports can be reduced without reference for higher MR field structural scanning or other modalities, and more FLE patients can benefit from epilepsy surgery candidacy.

Right ventricular myxoma in a patient with tetralogy of Fallot.

INTRODUCTION: Cardiac myxoma is the most common primary cardiac tumour in adulthood and may present in the context of Carney's complex. PRESENTATION OF CASE: A 32-year-old male with a history of repaired tetralogy of Fallot in childhood was admitted with severe pulmonary valve regurgitation and a mobile mass in the right ventricle. The patient underwent pulmonary valve replacement and mass excision. Pathology examination showed myxoma. DISCUSSION: In the majority of cases myxomas originate in the atria, nevertheless they can also be found in a ventricular cavity. Myxoma is a prevalent feature of Carney's complex, an inherited, autosomal disease, characterised by multiple tumours in several organs. Tetralogy of Fallot has also been described in association with Carney's complex. CONCLUSION: Coexistence of tetralogy of Fallot with a cardiac ventricular myxoma in a patient not affected from Carney's complex or other familial syndrome.

Assessment of myocardial partition coefficient of gadolinium (λ) in dilated cardiomyopathy and its impact on segmental and global systolic function.

PURPOSE: 1) To assess the myocardial partition coefficient (λ) of gadolinium quantified using T1 mapping in dilated cardiomyopathy (DCM); and 2) to assess the impact of increased λ on left ventricular (LV) circumferential strain and ejection fraction in DCM. MATERIALS AND METHODS: Seventeen patients with DCM and 11 controls were prospectively included. All patients and controls underwent a 1.5 T MRI using: 1) cine to quantify LV volumes and function; 2) tagging to quantify circumferential strain in mid-LV; 3) T1 mapping before and 9 minutes after contrast injection to quantify R1, ΔR1, and λ; and 4) inversion recovery 3D Flash was used to assess late gadolinium enhancement (LGE) 10 minutes after Gd DOTA injection (0.2 mmol/kg). We used Student's t-test to compare means, Pearson's test for correlation assessment, and a mixed linear model to integrate the dependency between myocardial segments. RESULTS: No difference in median λ was measured between patients with (0.52 [interquartile range = 0.48-0.56]) and without enhancement on LGE (0.51 [0.47-0.54]; P = 0.07). Circumferential strain value measured in each segment was correlated with the λ measured in the corresponding segment (r = 0.55; P < 0.0001). Multivariate analysis revealed a significant link between the λ in each segment and circumferential strain (0.002 ± 0.001; P = 0.009) and also with ejection fraction (-0.001 ± 0.0008; P = 0.04). CONCLUSION: In DCM, λ correlates independently with circumferential strain and ejection fraction, suggesting that there is a link between λ and systolic function.