Quantification of Significant Aortic Stenosis by Echocardiography versus Four-Dimensional Cardiac Computed Tomography: A Multi-Modality Imaging Study

Transthoracic echocardiography (TTE) grading of aortic stenosis (AS) is challenging when parameters are discrepant, and four-dimensional cardiac computed tomography (4D-CCT) is increasingly utilized for transcatheter intervention workup. We compared TTE and 4D-CCT measures contributing to AS quantification. AS patients (n = 80, age 86 ± 10 years, 71% men) referred for transcatheter replacement in 2014−2017 were retrospectively studied, 20 each with high-gradient AS (HG-AS), classical and paradoxical low-flow low-gradient AS (CLFLG-AS and PLFLG-AS), and normal-flow low-gradient AS (NFLG-AS). Correlation and Bland−Altman analyses were performed between TTE and 4D-CCT parameters. There were moderate-to-high TTE versus 4D-CCT correlations for left ventricular volumes, function, mass, and outflow tract dimensions (r = 0.51−0.88), though values were mostly significantly higher by 4D-CCT (p < 0.001). Compared with 4D-CCT planimetry of aortic valve area (AVA), TTE estimates had modest correlation (r = 0.37−0.43) but were significantly lower (by 0.15−0.32 cm2). The 4D-CCT estimate of LVSVi lead to significant reclassification of AS subtype defined by TTE. In conclusion, 4D-CCT quantified values were higher than TTE for the left ventricle and AVA, and the AS subtype was reclassified based on LVSVi by 4D-CCT, warranting further research to establish its clinical implications and optimal thresholds in severe AS management.

Double-blind randomized proof-of-concept trial of canakinumab in patients with COVID-19 associated cardiac injury and heightened inflammation

Aims

In coronavirus disease 2019 (COVID-19), myocardial injury is associated with systemic inflammation and higher mortality. Our aim was to perform a proof of concept trial with canakinumab, a monoclonal antibody to interleukin-1β, in patients with COVID-19, myocardial injury, and heightened inflammation.

Methods and results

This trial required hospitalization due to COVID-19, elevated troponin, and a C-reactive protein concentration more than 50 mg/L. The primary endpoint was time to clinical improvement at Day 14, defined as either an improvement of two points on a seven-category ordinal scale or discharge from the hospital. The secondary endpoint was mortality at Day 28. Forty-five patients were randomly assigned to canakinumab 600 mg (n = 15), canakinumab 300 mg (n = 14), or placebo (n = 16). There was no difference in time to clinical improvement compared to placebo [recovery rate ratio (RRR) for canakinumab 600 mg 1.15, 95% confidence interval (CI) 0.46-2.91; RRR for canakinumab 300 mg 0.61, 95% CI 0.23-1.64]. At Day 28, 3 (18.8%) of 15 patients had died in the placebo group, compared with 3 (21.4%) of 14 patients with 300 mg canakinumab, and 1 (6.7%) of 15 patients with 600 mg canakinumab. There were no treatment-related deaths, and adverse events were similar between groups.

Conclusion

There was no difference in time to clinical improvement at Day 14 in patients treated with canakinumab, and no safety concerns were identified. Future studies could focus on high dose canakinumab in the treatment arm and assess efficacy outcomes at Day 28.

Canakinumab to reduce deterioration of cardiac and respiratory function in SARS-CoV-2 associated myocardial injury with heightened inflammation (canakinumab in Covid-19 cardiac injury: The three C study)

BACKGROUND

In patients with Covid-19, myocardial injury and increased inflammation are associated with morbidity and mortality. We designed a proof-of-concept randomized controlled trial to evaluate whether treatment with canakinumab prevents progressive respiratory failure and worsening cardiac dysfunction in patients with SARS-CoV2 infection, myocardial injury, and high levels of inflammation.

HYPOTHESIS

The primary hypothesis is that canakiumab will shorten time to recovery.

METHODS

The three C study (canakinumab in Covid-19 Cardiac Injury, NCT04365153) is a double-blind, randomized controlled trial comparing canakinumab 300 mg IV, 600 mg IV, or placebo in a 1:1:1 ratio in hospitalized Covid-19 patients with elevations in troponin and C-reactive protein (CRP). The primary endpoint is defined as the time in days from randomization to either an improvement of two points on a seven category ordinal scale or discharge from the hospital, whichever occurs first up to 14 days postrandomization. The secondary endpoint is mortality at day 28. A total of 45 patients will be enrolled with an anticipated 5 month follow up period.

RESULTS

Baseline characteristics for the first 20 randomized patients reveal a predominantly male (75%), elderly population (median 67 years) with a high prevalence of hypertension (80%) and hyperlipidemia (75%). CRPs have been markedly elevated (median 16.2 mg/dL) with modest elevations in high-sensitivity troponin T (median 21 ng/L), in keeping with the concept of enrolling patients with early myocardial injury.

CONCLUSIONS

The three C study will provide insights regarding whether IL-1β inhibition may improve outcomes in patients with SARS-CoV2 associated myocardial injury and increased inflammation.

A Complicated Case of Transient Constrictive Pericarditis Secondary to Rivaroxaban-Associated Hemopericardium

A 72-year-old man on rivaroxaban developed effusive constrictive pericarditis secondary to hemopericardium. His condition improved with anti-inflammatory therapy supporting a diagnosis of transient constrictive pericarditis. On follow-up, residual constriction developed requiring surgical pericardiectomy. Although many cases with transient constrictive pericarditis resolve with medical management, some may progress and require pericardiectomy. (Level of Difficulty: Advanced.)

Founder Mutation in N Terminus of Cardiac Troponin I Causes Malignant Hypertrophic Cardiomyopathy

BACKGROUND

Cardiac troponin I (TNNI3) gene mutations account for 3% of hypertrophic cardiomyopathy and carriers have a heterogeneous phenotype, with increased risk of sudden cardiac death (SCD). Only one mutation (p.Arg21Cys) has been reported in the N terminus of the protein. In model organisms, it impairs PKA (protein kinase A) phosphorylation, increases calcium sensitivity, and causes diastolic dysfunction. The phenotype of this unique mutation in patients with hypertrophic cardiomyopathy remains unknown.

METHODS

We sequenced 29 families with hypertrophic cardiomyopathy enriched for pediatric-onset disease and identified 5 families with the TNNI3 p.Arg21Cys mutation. Using cascade screening, we studied the clinical phenotype of 57 individuals from the 5 families with TNNI3 p.Arg21Cys-related cardiomyopathy. We performed survival analysis investigating the age at first SCD in carriers of the mutation.

RESULTS

All 5 families with TNNI3 p.Arg21Cys were from South Lebanon. TNNI3 p.Arg21Cys-related cardiomyopathy manifested a malignant phenotype-SCD occurred in 30 (53%) of 57 affected individuals at a median age of 22.5 years. In select carriers without left ventricular hypertrophy on echocardiogram, SCD occurred, myocyte disarray was found on autopsy heart, and tissue Doppler and cardiac magnetic resonance imaging identified subclinical disease features such as diastolic dysfunction and late gadolinium enhancement.

CONCLUSIONS

The TNNI3 p.Arg21Cys mutation has a founder effect in South Lebanon and causes malignant hypertrophic cardiomyopathy with early SCD even in the absence of hypertrophy. Genetic diagnosis with this mutation may be sufficient for risk stratification for SCD.

Multi-modality imaging of cardiac amyloidosis: Contemporary update

Cardiac amyloidosis is a heterogeneous and challenging diagnostic disease with poor prognosis that is now being altered by introduction of new therapies. Echocardiography remains the first-line imaging tool, and when disease is suspected on echocardiography, cardiac magnetic resonance imaging and nuclear imaging play critical roles in the non-invasive diagnosis and evaluation of cardiac amyloidosis. Advances in multi-modality cardiac imaging allowing earlier diagnosis and initiation of novel therapies have significantly improved the outcomes in these patients. Cardiac imaging also plays important roles in the risk stratification of patients presenting with cardiac amyloidosis. In the current review, we provide a clinical and imaging focused update, and importantly outline the imaging protocols, diagnostic and prognostic utility of multimodality cardiac imaging in the assessment of cardiac amyloidosis.

Novel EIF2AK4 mutations in histologically proven pulmonary capillary hemangiomatosis and hereditary pulmonary arterial hypertension

Background

Pulmonary hypertension (PH) remains one of the rarest and deadliest diseases. Pulmonary Capillary Hemangiomatosis (PCH) is one of the sub-classes of PH. It was identified using histological and molecular tools and is characterized by the proliferation of capillaries into the alveolar septae. Mutations in the gene encoding the eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) have recently been linked to this particular subgroup of PH.

Methods

In our effort to unveil the genetic basis of idiopathic and familial cases of PH in Lebanon, we have used whole exome sequencing to document known and/or novel mutations in genes that could explain the underlying phenotype.

Results

We showed bi-allelic mutations in EIF2AK4 in two non-consanguineous families: a novel non-sense mutation c.1672C > T (p.Q558*) and a previously documented deletion c.560_564drlAAGAA (p.K187Rfs9*). Our histological analysis coupled with the CT-scan results showed that the two patients with the p.Q558* mutation have PH. In contrast, only one of the individuals harboring the p.K187Rfs9* variant has a documented PCH while his older brother remains asymtomatic. Differential analysis of the variants in the genes of the neighboring network of EIF2AK4 between the two siblings identified a couple of interesting missense mutations that could account for this discrepancy.

Conclusion

These findings represent a novel documentation of the involvement of EIF2AK4 in the different aspects of pulmonary hypertension. The absence of a molecular mechanism that relates the abrogated function of the protein to the phenotype is still a major hurdle in our understanding of the disease.

High Precision Digitization of Paper-Based ECG Records: A Step Toward Machine Learning

Introduction: The electrocardiogram (ECG) plays an important role in the diagnosis of heart diseases. However, most patterns of diseases are based on old datasets and stepwise algorithms that provide limited accuracy. Improving diagnostic accuracy of the ECG can be done by applying machine learning algorithms. This requires taking existing scanned or printed ECGs of old cohorts and transforming the ECG signal to the raw digital (time (milliseconds), voltage (millivolts)) form. Objectives: We present a MATLAB-based tool and algorithm that converts a printed or scanned format of the ECG into a digitized ECG signal. Methods: 30 ECG scanned curves are utilized in our study. An image processing method is first implemented for detecting the ECG regions of interest and extracting the ECG signals. It is followed by serial steps that digitize and validate the results. Results: The validation demonstrates very high correlation values of several standard ECG parameters: PR interval 0.984 +/−0.021 (p-value < 0.001), QRS interval 1+/− SD (p-value < 0.001), QT interval 0.981 +/− 0.023 p-value < 0.001, and RR interval 1 +/− 0.001 p-value < 0.001. Conclusion: Digitized ECG signals from existing paper or scanned ECGs can be obtained with more than 95% of precision. This makes it possible to utilize historic ECG signals in machine learning algorithms to identify patterns of heart diseases and aid in the diagnostic and prognostic evaluation of patients with cardiovascular disease.

A speckle-tracking strain-based artificial neural network model to differentiate cardiomyopathy type

Objectives. In heart failure, invasive angiography is often employed to differentiate ischaemic from non-ischaemic cardiomyopathy. We aim to examine the predictive value of echocardiographic strain features alone and in combination with other features to differentiate ischaemic from non-ischaemic cardiomyopathy, using artificial neural network (ANN) and logistic regression modelling. Design. We retrospectively identified 204 consecutive patients with an ejection fraction <50% and a diagnostic angiogram. Patients were categorized as either ischaemic (n = 146) or non-ischaemic cardiomyopathy (n = 58). For each patient, left ventricular strain parameters were obtained. Additionally, regional wall motion abnormality, 13 electrocardiographic (ECG) features and six demographic features were retrieved for analysis. The entire cohort was randomly divided into a derivation and a validation cohort. Using the parameters retrieved, logistic regression and ANN models were developed in the derivation cohort to differentiate ischaemic from non-ischaemic cardiomyopathy, the models were then tested in the validation cohort. Results. A final strain-based ANN model, full feature ANN model and full feature logistic regression model were developed and validated, F₁ scores were 0.82, 0.79 and 0.63, respectively. Conclusions. Both ANN models were more accurate at predicting cardiomyopathy type than the logistic regression model. The strain-based ANN model should be validated in other cohorts. This model or similar models could be used to aid the diagnosis of underlying heart failure aetiology in the form of the online calculator (https://cimti.usj.edu.lb/strain/index.html) or built into echocardiogram software.

Clinical and genetic characteristics of pulmonary arterial hypertension in Lebanon

Background

Pulmonary arterial hypertension (PAH) is a rare disease with an incidence rate of 2–6 cases per million per year. Our knowledge of the disease in the Middle East and North Africa (MENA) region is limited by the small number of clinical studies and the complete absence of genetic studies.

Methods

Our aim was to shed light on the clinical and genetic characteristics of PAH in Lebanon and the region by using exome sequencing on PAH patients referred to the American University of Beirut Medical Center (AUBMC). Twenty-one idiopathic, hereditary and Congenital Heart Disease (CHD) PAH patients were prospectively recruited, their clinical data summarized, and sequencing performed.

Results

The mean age at diagnosis was 33 years with a female preponderance of 70%. The mean pulmonary artery pressure at the time of diagnosis was 55. Genetic testing showed that 5 out of 19 idiopathic and Congenital Heart Disease PAH patients had Bone Morphogenetic Protein Receptor 2 (BMPR2) mutations at 25% prevalence, with 2 of these patients exhibiting a novel mutation. It also showed the presence of 1 BMPR2 mutation with 100% penetrance in a heritable PAH family. In the remaining cases, the lack of a complete genotype/phenotype correlation entailed a multigenic inheritance; suspected interactions involved previously associated genes T-box transcription factor 4 (TBX4), Bone Morphogenic Protein 10 (BMP10) and Growth Differentiation Factor 2 (GDF2).

Conclusions

This is the first study that looks into the genetic causes of PAH, including known and new BMPR2 mutations, in the MENA region. It is also the first study to characterize the clinical features of the disease in Lebanon.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0608-7) contains supplementary material, which is available to authorized users.

Linezolid Toxicity and Mitochondrial Susceptibility: A Novel Neurological Complication in a Lebanese Patient

The recent rise in the use of linezolid to treat a variety of resistant pathogens has uncovered many side effects. Some patients develop lactic acidosis, myelosuppression, optic or peripheral neuropathies, and myopathies. We evaluated an elderly patient who presented to the Emergency Room with linezolid toxicity and a novel neurologic complication characterized by bilateral globi pallidi necrosis. Mitochondrial ribosome inhibition was described to be the predisposing factor. The patient belongs to the mitochondrial J1 haplotype known to be associated with side effects of the drug. We recommend based on the molecular profile of the illness pretreatment considerations and complication management.