T cell responses to SARS-CoV-2 spike cross-recognize Omicron

The SARS-CoV-2 Omicron variant (B.1.1.529) has multiple spike protein mutations1,2 that contribute to viral escape from antibody neutralization3-6 and reduce vaccine protection from infection7,8. The extent to which other components of the adaptive response such as T cells may still target Omicron and contribute to protection from severe outcomes is unknown. Here we assessed the ability of T cells to react to Omicron spike protein in participants who were vaccinated with Ad26.CoV2.S or BNT162b2, or unvaccinated convalescent COVID-19 patients (n = 70). Between 70% and 80% of the CD4+ and CD8+ T cell response to spike was maintained across study groups. Moreover, the magnitude of Omicron cross-reactive T cells was similar for Beta (B.1.351) and Delta (B.1.617.2) variants, despite Omicron harbouring considerably more mutations. In patients who were hospitalized with Omicron infections (n = 19), there were comparable T cell responses to ancestral spike, nucleocapsid and membrane proteins to those in patients hospitalized in previous waves dominated by the ancestral, Beta or Delta variants (n = 49). Thus, despite extensive mutations and reduced susceptibility to neutralizing antibodies of Omicron, the majority of T cell responses induced by vaccination or infection cross-recognize the variant. It remains to be determined whether well-preserved T cell immunity to Omicron contributes to protection from severe COVID-19 and is linked to early clinical observations from South Africa and elsewhere9-12.

Pheochromocytoma Is Characterized by Catecholamine-Mediated Myocarditis, Focal and Diffuse Myocardial Fibrosis, and Myocardial Dysfunction

BACKGROUND

Pheochromocytoma is associated with catecholamine-induced cardiac toxicity, but the extent and nature of cardiac involvement in clinical cohorts is not well-characterized.

OBJECTIVES

This study characterized the cardiac phenotype in patients with pheochromocytoma using cardiac magnetic resonance (CMR).

METHODS

A total of 125 subjects were studied, including patients with newly diagnosed pheochromocytoma (n = 29), patients with previously surgically cured pheochromocytoma (n = 31), healthy control subjects (n = 51), and hypertensive control subjects (HTN) (n = 14), using CMR (1.5-T) cine, strain imaging by myocardial tagging, late gadolinium enhancement, and native T1 mapping (Shortened Modified Look-Locker Inversion recovery [ShMOLLI]).

RESULTS

Patients who were newly diagnosed with pheochromocytoma, compared with healthy and HTN control subjects, had impaired left ventricular (LV) ejection fraction (<56% in 38% of patients), peak systolic circumferential strain (p < 0.05), and diastolic strain rate (p < 0.05). They had higher myocardial T1 (974 ± 25 ms, as compared with 954 ± 16 ms in healthy and 958 ± 23 ms in HTN subjects; p < 0.05), areas of myocarditis (median 22% LV with T1 >990 ms, as compared with 1% in healthy and 2% in HTN subjects; p < 0.05), and focal fibrosis (59% had nonischemic late gadolinium enhancement, as compared with 14% in HTN subjects). Post-operatively, impaired LV ejection fraction typically normalized, but systolic and diastolic strain impairment persisted. Focal fibrosis (median 5% LV) and T1 abnormalities (median 12% LV) remained, the latter of which may suggest some diffuse fibrosis. Previously cured patients demonstrated abnormal diastolic strain rate (p < 0.001), myocardial T1 (median 12% LV), and small areas of focal fibrosis (median 1% LV). LV mass index was increased in HTN compared with healthy control subjects (p < 0.05), but not in the 2 pheochromocytoma groups.

CONCLUSIONS

This first systematic CMR study characterizing the cardiac phenotype in pheochromocytoma showed that cardiac involvement was frequent and, for some variables, persisted after curative surgery. These effects surpass those of hypertensive heart disease alone, supporting a direct role of catecholamine toxicity that may produce subtle but long-lasting myocardial alterations.

Prior infection with SARS-CoV-2 boosts and broadens Ad26.COV2.S immunogenicity in a variant-dependent manner

The Johnson and Johnson Ad26.COV2.S single-dose vaccine represents an attractive option for coronavirus disease 2019 (COVID-19) vaccination in countries with limited resources. We examined the effect of prior infection with different SARS-CoV-2 variants on Ad26.COV2.S immunogenicity. We compared participants who were SARS-CoV-2 naive with those either infected with the ancestral D614G virus or infected in the second wave when Beta predominated. Prior infection significantly boosts spike-binding antibodies, antibody-dependent cellular cytotoxicity, and neutralizing antibodies against D614G, Beta, and Delta; however, neutralization cross-reactivity varied by wave. Robust CD4 and CD8 T cell responses are induced after vaccination, regardless of prior infection. T cell recognition of variants is largely preserved, apart from some reduction in CD8 recognition of Delta. Thus, Ad26.COV2.S vaccination after infection could result in enhanced protection against COVID-19. The impact of the infecting variant on neutralization breadth after vaccination has implications for the design of second-generation vaccines based on variants of concern.

Escape from recognition of SARS-CoV-2 variant spike epitopes but overall preservation of T cell immunity

SARS-CoV-2 variants that escape neutralization and potentially affect vaccine efficacy have emerged. T cell responses play a role in protection from reinfection and severe disease, but the potential for spike mutations to affect T cell immunity is incompletely understood. We assessed neutralizing antibody and T cell responses in 44 South African COVID-19 patients either infected with the Beta variant (dominant from November 2020 to May 2021) or infected before its emergence (first wave, Wuhan strain) to provide an overall measure of immune evasion. We show that robust spike-specific CD4 and CD8 T cell responses were detectable in Beta-infected patients, similar to first-wave patients. Using peptides spanning the Beta-mutated regions, we identified CD4 T cell responses targeting the wild-type peptides in 12 of 22 first-wave patients, all of whom failed to recognize corresponding Beta-mutated peptides. However, responses to mutated regions formed only a small proportion (15.7%) of the overall CD4 response, and few patients (3 of 44) mounted CD8 responses that targeted the mutated regions. Among the spike epitopes tested, we identified three epitopes containing the D215, L18, or D80 residues that were specifically recognized by CD4 T cells, and their mutated versions were associated with a loss of response. This study shows that despite loss of recognition of immunogenic CD4 epitopes, CD4 and CD8 T cell responses to Beta are preserved overall. These observations may explain why several vaccines have retained the ability to protect against severe COVID-19 even with substantial loss of neutralizing antibody activity against Beta.

Outcomes of laboratory-confirmed SARS-CoV-2 infection in the Omicron-driven fourth wave compared with previous waves in the Western Cape Province, South Africa

OBJECTIVES

The objective was to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, assess the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection and determine whether protection against severe disease conferred by prior infection and/or vaccination was maintained.

METHODS

In this cohort study, we included public sector patients aged ≥20 years with a laboratory-confirmed COVID-19 diagnosis between 14 November and 11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalisation or death and any hospitalisation or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection.

RESULTS

We included 5144 patients from wave four and 11,609 from prior waves. The risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted hazard ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR: 0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58).

CONCLUSIONS

In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for a modest reduction in risk of severe hospitalisation or death compared to the Delta-driven wave.

Aortic 4D flow: quantification of signal-to-noise ratio as a function of field strength and contrast enhancement for 1.5T, 3T, and 7T

PURPOSE

To investigate for the first time the feasibility of aortic four-dimensional (4D) flow at 7T, both contrast enhanced (CE) and non-CE. To quantify the signal-to-noise ratio (SNR) in aortic 4D flow as a function of field strength and CE with gadobenate dimeglumine (MultiHance).

METHODS

Six healthy male volunteers were scanned at 1.5T, 3T, and 7T with both non-CE and CE acquisitions. Temporal SNR was calculated. Flip angle optimization for CE 4D flow was carried out using Bloch simulations that were validated against in vivo measurements.

RESULTS

The 7T provided 2.2 times the SNR of 3T while 3T provided 1.7 times the SNR of 1.5T in non-CE acquisitions in the descending aorta. The SNR gains achieved by CE were 1.8-fold at 1.5T, 1.7-fold at 3T, and 1.4-fold at 7T, respectively.

CONCLUSION

The 7T provides a new tool to explore aortic 4D flow, yielding higher SNR that can be used to push the boundaries of acceleration and resolution. Field strength and contrast enhancement at all fields provide significant improvements in SNR.

Diagnosis and risk stratification in hypertrophic cardiomyopathy using machine learning wall thickness measurement: a comparison with human test-retest performance

BACKGROUND

Left ventricular maximum wall thickness (MWT) is central to diagnosis and risk stratification of hypertrophic cardiomyopathy, but human measurement is prone to variability. We developed an automated machine learning algorithm for MWT measurement and compared precision (reproducibility) with that of 11 international experts, using a dataset of patients with hypertrophic cardiomyopathy.

METHODS

60 adult patients with hypertrophic cardiomyopathy, including those carrying hypertrophic cardiomyopathy gene mutations, were recruited at three institutes in the UK from August, 2018, to September, 2019: Barts Heart Centre, University College London Hospital (The Heart Hospital), and Leeds Teaching Hospitals NHS Trust. Participants had two cardiovascular magnetic resonance scans (test and retest) on the same day, ensuring no biological variability, using four cardiac MRI scanner models represented across two manufacturers and two field strengths. End-diastolic short-axis MWT was measured in test and retest by 11 international experts (from nine centres in six countries) and an automated machine learning method, which was trained to segment endocardial and epicardial contours on an independent, multicentre, multidisease dataset of 1923 patients. Machine learning MWT measurement was done with a method based on solving Laplace's equation. To assess test-retest reproducibility, we estimated the absolute test-retest MWT difference (precision), the coefficient of variation (CoV) for duplicate measurements, and the number of patients reclassified between test and retest according to different thresholds (MWT >15 mm and >30 mm). We calculated the sample size required to detect a prespecified MWT change between pairs of scans for machine learning and each expert.

FINDINGS

1440 MWT measurements were analysed, corresponding to two scans from 60 participants by 12 observers (11 experts and machine learning). Experts differed in the MWT they measured, ranging from 14·9 mm (SD 4·2) to 19·0 mm (4·7; p<0·0001 for trend). Machine learning-measured mean MWT was 16·8 mm (4·1). Machine learning precision was superior, with a test-retest difference of 0·7 mm (0·6) compared with experts, who ranged from 1·1 mm (0·9) to 3·7 mm (2·0; p values for machine learning vs expert comparison ranging from <0·0001 to 0·0073) and a significantly lower CoV than for all experts (4·3% [95% CI 3·3-5·1] vs 5·7-12·1% across experts). On average, 38 (64%) patients were designated as having MWT greater than 15 mm by machine learning compared with 27 (45%) to 50 (83%) patients by experts; five (8%) patients were reclassified in test-retest by machine learning compared with four (7%) to 12 (20%) by experts. With a cutoff point of more than 30 mm for implantable cardioverter-defibrillator, three experts would have changed recommendations between tests a total of four times, but machine learning was consistent. Using machine learning, a clinical trial to detect a 2 mm MWT change would need 2·3 times (range 1·6-4·6) fewer patients.

INTERPRETATION

In this preliminary study, machine learning MWT measurement in hypertrophic cardiomyopathy is superior to human experts with potential implications for diagnosis, risk stratification, and clinical trials.

FUNDING

European Regional Development Fund and Barts Charity.

An overview of heart failure in low- and middle-income countries

Heart failure (HF) is a global public health concern with disproportionate socioeconomic, morbidity and mortality burden on low- and middle-income countries (LMICs). This review summarises contemporary data on the demographic and clinical characteristics, aetiologies, treatment, economic burden and outcomes of HF in LMICs. Patients with HF in LMICs are younger than those from high-income countries (HICs) and present at advanced stages of the disease. Hypertension, ischaemic heart disease (IHD), cardiomyopathy (CMO), and rheumatic heart disease (RHD) are the leading causes of HF in LMICs. The contribution of infectious diseases to HF remains prominent in many LMICs. Most health facilities in LMICs lack adequate diagnostic tools for HF, and the use of evidence-based medical and device therapies is suboptimal. Further, HF in LMICs is associated with prolonged hospital stay and high in-hospital and one-year mortality. Finally, HF has profound economic impact on individual patients who, mostly, have no health insurance, and on societies where patients are young, comprising those who have the greatest potential to contribute to economic productivity.

The oral microbiome in the pathophysiology of cardiovascular disease

Despite advances in our understanding of the pathophysiology of many cardiovascular diseases (CVDs) and expansion of available therapies, the global burden of CVD-associated morbidity and mortality remains unacceptably high. Important gaps remain in our understanding of the mechanisms of CVD and determinants of disease progression. In the past decade, much research has been conducted on the human microbiome and its potential role in modulating CVD. With the advent of high-throughput technologies and multiomics analyses, the complex and dynamic relationship between the microbiota, their 'theatre of activity' and the host is gradually being elucidated. The relationship between the gut microbiome and CVD is well established. Much less is known about the role of disruption (dysbiosis) of the oral microbiome; however, interest in the field is growing, as is the body of literature from basic science and animal and human investigations. In this Review, we examine the link between the oral microbiome and CVD, specifically coronary artery disease, stroke, peripheral artery disease, heart failure, infective endocarditis and rheumatic heart disease. We discuss the various mechanisms by which oral dysbiosis contributes to CVD pathogenesis and potential strategies for prevention and treatment.

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation

Background Atrial fibrillation ( AF ) is associated with myocardial infarction, and patients with AF and no obstructive coronary artery disease can present with symptoms and evidence of cardiac ischemia. We hypothesized that microvascular coronary dysfunction underlies these observations. Methods and Results Myocardial blood flow ( MBF ) at baseline and during adenosine stress and left ventricular and left atrial function were evaluated by magnetic resonance in 49 patients with AF (25 paroxysmal, 24 persistent) with no history of epicardial coronary artery disease or diabetes mellitus, before and 6 to 9 months after ablation. Findings were compared with those obtained in matched controls in sinus rhythm (n=25). Before ablation, patients with AF had impaired left atrial function and left ventricular ejection fraction and strain indices (all P<0.05 versus controls). MBF was impaired in patients both under baseline conditions (1.21±0.24 mL/min per g·[mm Hg·bpm/104]-1 versus 1.34±0.28 mL/min per g·[mm Hg·bpm/104]-1 in controls, P=0.044) and during adenosine stress (2.29±0.48 mL/min per g versus 2.73±0.37 mL/min per g in controls, P<0.001). Under baseline conditions, MBF correlated with left ventricular strain and left atrial function (all P≤0.001), so that cardiac function was most impaired in patients with the lowest MBF . Baseline and stress MBF remained unchanged postablation (both P=ns), and baseline MBF showed similar correlations with functional indices to those present preablation (all P≤0.001). Conclusions Baseline and stress MBF are significantly impaired in patients with AF but no epicardial coronary artery disease. Reduction in MBF is proportional to severity of left ventricular and left atrial dysfunction, even after successful ablation. Coronary microvascular dysfunction may be a relevant pathophysiological mechanism in patients with a history of AF .

Mapping experiences and perspectives of equity in international health collaborations: a scoping review

BACKGROUND

Whilst global health research often involves international collaborations, achieving or promoting equity within collaborations remains a key challenge, despite established conceptual approaches and the development of frameworks and guidelines to promote equity. There have also been several empirical studies documenting researchers' experiences of inequity and views on what is required to advance equity in global health collaborations. While these empirical studies provide critical insights, there has been no attempt to systematically synthetize what constitutes equity and how it can be achieved. To address this gap, we conducted a scoping review of qualitative studies, opinion and editorial pieces about what equity is and how it can be promoted in international collaborations.

METHODS

We conducted a scoping review to explore domains of equity in international health collaborations. This review included qualitative studies and opinion pieces or editorial pieces on equity in international health collaborations. We mapped the data and identified common themes using a thematic analysis approach.

RESULTS

This initial search retrieved a total of 7611 papers after removing duplicates. A total of 11 papers were included in this review, 10 empirical studies and 1 editorial piece. We conducted our search between October - November 2019. We identified 10 key domains which are important for promoting equity in international collaborations: funding; capacity building; authorship; sample ownership and export; trust; research agreement; acknowledging inequality; recognition and communication.

DISCUSSION

Our findings suggest that for international collaborations to be considered more equitable, it must at least consider the 10 domains we highlighted. The 10 domains map onto five key aspects of social justice theory, namely avoiding unequal power relations like subordination, group recognition and affirmation, promoting the well-being of all, inclusion in decision-making and ensuring self-development.

Associations of Race and Ethnicity With Presentation and Outcomes of Hypertrophic Cardiomyopathy: JACC Focus Seminar 6/9

Significant racial and ethnicity-based disparities in clinical presentation, management, and outcome of hypertrophic cardiomyopathy (HCM) are reported. Black patients with HCM are more likely to present with heart failure but are less commonly referred for symptom management, sudden cardiac death stratification, surgical septal myectomy, or for implantable cardioverter-defibrillators, all interventions that increase survival. Prevalence of bystander cardiopulmonary resuscitation is lower for Black patients than for White patients. Black patients with HCM have decreased survival after hospital discharge following out-of-hospital cardiac arrest. Biomedical and social interventions are urgently needed to reduce ethnicity-based disparities, which have an impact on outcomes in HCM and other cardiovascular diseases. There is also a need to focus on implementation science to support durable adoption of evidence-based therapies in Black patients and communities.

Prognostic value of NT-proBNP for myocardial recovery in peripartum cardiomyopathy (PPCM)

Introduction

Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure worldwide. Although a significant number of women recover their left ventricular (LV) function within 12 months, some remain with persistently reduced systolic function.

Methods

Knowledge gaps exist on predictors of myocardial recovery in PPCM. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the only clinically established biomarker with diagnostic value in PPCM. We aimed to establish whether NT-proBNP could serve as a predictor of LV recovery in PPCM, as measured by LV end-diastolic volume (LVEDD) and LV ejection fraction (LVEF).

Results

This study of 35 women with PPCM (mean age 30.0 ± 5.9 years) had a median NT-proBNP of 834.7 pg/ml (IQR 571.2–1840.5) at baseline. Within the first year of follow-up, 51.4% of the cohort recovered their LV dimensions (LVEDD < 55 mm) and systolic function (LVEF > 50%). Women without LV recovery presented with higher NT-proBNP at baseline. Multivariable regression analyses demonstrated that NT-proBNP of ≥ 900 pg/ml at the time of diagnosis was predictive of failure to recover LVEDD (OR 0.22, 95% CI 0.05–0.95, P = 0.043) or LVEF (OR 0.20 [95% CI 0.04–0.89], p = 0.035) at follow-up.

Conclusions

We have demonstrated that NT-proBNP has a prognostic value in predicting LV recovery of patients with PPCM. Patients with NT-proBNP of ≥ 900 pg/ml were less likely to show any improvement in LVEF or LVEDD. Our findings have implications for clinical practice as patients with higher NT-proBNP might require more aggressive therapy and more intensive follow-up. Point-of-care NT-proBNP for diagnosis and risk stratification warrants further investigation.

Quality assurance of quantitative cardiac T1-mapping in multicenter clinical trials - A T1 phantom program from the hypertrophic cardiomyopathy registry (HCMR) study

BACKGROUND

Quantitative cardiovascular magnetic resonance T1-mapping is increasingly used for myocardial tissue characterization. However, the lack of standardization limits direct comparability between centers and wider roll-out for clinical use or trials.

PURPOSE

To develop a quality assurance (QA) program assuring standardized T1 measurements for clinical use.

METHODS

MR phantoms manufactured in 2013 were distributed, including ShMOLLI T1-mapping and reference T1 and T2 protocols. We first studied the T1 and T2 dependency on temperature and phantom aging using phantom datasets from a single site over 4 years. Based on this, we developed a multiparametric QA model, which was then applied to 78 scans from 28 other multi-national sites.

RESULTS

T1 temperature sensitivity followed a second-order polynomial to baseline T1 values (R² > 0.996). Some phantoms showed aging effects, where T1 drifted up to 49% over 40 months. The correlation model based on reference T1 and T2, developed on 1004 dedicated phantom scans, predicted ShMOLLI-T1 with high consistency (coefficient of variation 1.54%), and was robust to temperature variations and phantom aging. Using the 95% confidence interval of the correlation model residuals as the tolerance range, we analyzed 390 ShMOLLI T1-maps and confirmed accurate sequence deployment in 90%(70/78) of QA scans across 28 multiple centers, and categorized the rest with specific remedial actions.

CONCLUSIONS

The proposed phantom QA for T1-mapping can assure correct method implementation and protocol adherence, and is robust to temperature variation and phantom aging. This QA program circumvents the need of frequent phantom replacements, and can be readily deployed in multicenter trials.

Cardiovascular magnetic resonance for evaluation of cardiac involvement in COVID-19: recommendations by the Society for Cardiovascular Magnetic Resonance

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.

Considering equity in global health collaborations: A qualitative study on experiences of equity

International collaborations have become the standard model for global health research and often include researchers and institutions from high income countries (HICs) and low- and middle-income countries (LMICs). While such collaborations are important for generating new knowledge that will help address global health inequities, there is evidence to suggest that current forms of collaboration may reproduce unequal power relations. Therefore, we conducted a qualitative study with scientists, researchers and those involved in research management, working in international health collaborations. Interviews were conducted between October 2019 and March 2020. We conducted 13 interviews with 15 participants. From our findings, we derive three major themes. First, our results reflect characteristics of equitable, collaborative research relationships. Here we find both relational features, specifically trust and belonging, and structural features, including clear contractual agreements, capacity building, inclusive divisions of labour, and the involvement of local communities. Second, we discuss obstacles to develop equitable collaborations. These include exclusionary labour practices, donor-driven research agendas, overall research culture, lack of accountability and finally, the inadequate financing of indirect costs for LMIC institutions. Third, we discuss the responsibilities for promoting science equity of funders, LMIC researchers, LMIC institutions, and LMIC governments. While other empirical studies have suggested similar features of equity, our findings extend these features to include local communities as collaborators in research projects and not only as beneficiaries. We also suggest the importance of funders paying for indirect costs, without which the capacity of LMIC institutions will continually erode. And finally, our study shows the responsibilities of LMIC actors in developing equitable collaborations, which have largely been absent from the literature.

Cardiovascular disease in women: insights from magnetic resonance imaging

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.

Myocardial Steatosis Among Antiretroviral Therapy-Treated People With Human Immunodeficiency Virus Participating in the REPRIEVE Trial

BACKGROUND

People with human immunodeficiency virus (PWH) face increased risks for heart failure and adverse heart failure outcomes. Myocardial steatosis predisposes to diastolic dysfunction, a heart failure precursor. We aimed to characterize myocardial steatosis and associated potential risk factors among a subset of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) participants.

METHODS

Eighty-two PWH without known heart failure successfully underwent cardiovascular magnetic resonance spectroscopy, yielding data on intramyocardial triglyceride (IMTG) content (a continuous marker for myocardial steatosis extent). Logistic regression models were applied to investigate associations between select clinical characteristics and odds of increased or markedly increased IMTG content.

RESULTS

Median (Q1, Q3) IMTG content was 0.59% (0.28%, 1.15%). IMTG content was increased (> 0.5%) among 52% and markedly increased (> 1.5%) among 22% of participants. Parameters associated with increased IMTG content included age (P = .013), body mass index (BMI) ≥ 25 kg/m2 (P = .055), history of intravenous drug use (IVDU) (P = .033), and nadir CD4 count < 350 cells/mm³ (P = .055). Age and BMI ≥ 25 kg/m2 were additionally associated with increased odds of markedly increased IMTG content (P = .049 and P = .046, respectively).

CONCLUSIONS

A substantial proportion of antiretroviral therapy-treated PWH exhibited myocardial steatosis. Age, BMI ≥ 25 kg/m2, low nadir CD4 count, and history of IVDU emerged as possible risk factors for myocardial steatosis in this group.

CLINICAL TRIALS REGISTRATION

NCT02344290; NCT03238755.

Effects of tuberculosis and/or HIV-1 infection on COVID-19 presentation and immune response in Africa

Few studies from Africa have described the clinical impact of co-infections on SARS-CoV-2 infection. Here, we investigate the presentation and outcome of SARS-CoV-2 infection in an African setting of high HIV-1 and tuberculosis prevalence by an observational case cohort of SARS-CoV-2 patients. A comparator group of non SARS-CoV-2 participants is included. The study includes 104 adults with SARS-CoV-2 infection of whom 29.8% are HIV-1 co-infected. Two or more co-morbidities are present in 57.7% of participants, including HIV-1 (30%) and active tuberculosis (14%). Amongst patients dually infected by tuberculosis and SARS-CoV-2, clinical features can be typical of either SARS-CoV-2 or tuberculosis: lymphopenia is exacerbated, and some markers of inflammation (D-dimer and ferritin) are further elevated (p < 0.05). Amongst HIV-1 co-infected participants those with low CD4 percentage strata exhibit reduced total, but not neutralising, anti-SARS-CoV-2 antibodies. SARS-CoV-2 specific CD8 T cell responses are present in 35.8% participants overall but undetectable in combined HIV-1 and tuberculosis. Death occurred in 30/104 (29%) of all COVID-19 patients and in 6/15 (40%) of patients with coincident SARS-CoV-2 and tuberculosis. This shows that in a high incidence setting, tuberculosis is a common co-morbidity in patients admitted to hospital with COVID-19. The immune response to SARS-CoV-2 is adversely affected by co-existent HIV-1 and tuberculosis.

Human immunodeficiency virus-associated heart failure in sub-Saharan Africa: evolution in the epidemiology, pathophysiology, and clinical manifestations in the antiretroviral era

The survival of patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) who have access to highly active antiretroviral therapy (ART) has dramatically increased in recent times. This review focuses on HIV‐associated heart failure in sub‐Saharan Africa (SSA). In HIV infected persons, heart failure may be related to pathology of the pericardium, the myocardium, the valves, the conduction system, or the coronary and pulmonary vasculature. HIV‐associated heart failure can be because of direct consequences of HIV infection, autoimmune reactions, pro‐inflammatory cytokines, opportunistic infections (OIs) or neoplasms, use of ART or therapy for OIs and presence of traditional cardiovascular risk factors. Myocardial involvement includes diastolic dysfunction, asymptomatic left ventricular dysfunction, cardiomyopathy, myocarditis, fibrosis, and steatosis. Pericardial diseases include pericarditis, pericardial effusions (rarely causing tamponade), pericardial constriction, and effusive‐constrictive syndromes. Coronary artery disease is commonly reported in industrial nations, although its prevalence is thought to be low in HIV‐infected persons from SSA.

Bringing MRI to low- and middle-income countries: Directions, challenges and potential solutions

The global disparity of magnetic resonance imaging (MRI) is a major challenge, with many low- and middle-income countries (LMICs) experiencing limited access to MRI. The reasons for limited access are technological, economic and social. With the advancement of MRI technology, we explore why these challenges still prevail, highlighting the importance of MRI as the epidemiology of disease changes in LMICs. In this paper, we establish a framework to develop MRI with these challenges in mind and discuss the different aspects of MRI development, including maximising image quality using cost-effective components, integrating local technology and infrastructure and implementing sustainable practices. We also highlight the current solutions-including teleradiology, artificial intelligence and doctor and patient education strategies-and how these might be further improved to achieve greater access to MRI.

Post-pandemic memory T cell response to SARS-CoV-2 is durable, broadly targeted, and cross-reactive to the hypermutated BA.2.86 variant

Ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolution has given rise to recombinant Omicron lineages that dominate globally (XBB.1), as well as the emergence of hypermutated variants (BA.2.86). In this context, durable and cross-reactive T cell immune memory is critical for continued protection against severe COVID-19. We examined T cell responses to SARS-CoV-2 approximately 1.5 years since Omicron first emerged. We describe sustained CD4+ and CD8+ spike-specific T cell memory responses in healthcare workers in South Africa (n = 39) who were vaccinated and experienced at least one SARS-CoV-2 infection. Spike-specific T cells are highly cross-reactive with all Omicron variants tested, including BA.2.86. Abundant nucleocapsid and membrane-specific T cells are detectable in most participants. The bulk of SARS-CoV-2-specific T cell responses have an early-differentiated phenotype, explaining their persistent nature. Overall, hybrid immunity leads to the accumulation of spike and non-spike T cells evident 3.5 years after the start of the pandemic, with preserved recognition of highly mutated SARS-CoV-2 variants.

Outcomes of laboratory-confirmed SARS-CoV-2 infection during resurgence driven by Omicron lineages BA.4 and BA.5 compared with previous waves in the Western Cape Province, South Africa

Objective

We aimed to compare clinical severity of Omicron BA.4/BA.5 infection with BA.1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in the Western Cape, South Africa, using timing of infection to infer the lineage/variant causing infection.

Methods

We included public sector patients aged ≥20 years with laboratory-confirmed COVID-19 between 1-21 May 2022 (BA.4/BA.5 wave) and equivalent prior wave periods. We compared the risk between waves of (i) death and (ii) severe hospitalization/death (all within 21 days of diagnosis) using Cox regression adjusted for demographics, comorbidities, admission pressure, vaccination and prior infection.

Results

Among 3,793 patients from the BA.4/BA.5 wave and 190,836 patients from previous waves the risk of severe hospitalization/death was similar in the BA.4/BA.5 and BA.1 waves (adjusted hazard ratio [aHR] 1.12; 95% confidence interval [CI] 0.93; 1.34). Both Omicron waves had lower risk of severe outcomes than previous waves. Prior infection (aHR 0.29, 95% CI 0.24; 0.36) and vaccination (aHR 0.17; 95% CI 0.07; 0.40 for boosted vs. no vaccine) were protective.

Conclusion

Disease severity was similar amongst diagnosed COVID-19 cases in the BA.4/BA.5 and BA.1 periods in the context of growing immunity against SARS-CoV-2 due to prior infection and vaccination, both of which were strongly protective.

Impact of Racial and Ethnic Disparities on Patients With Dilated Cardiomyopathy: JACC Focus Seminar 7/9

Significant race- and ethnicity-based disparities among those diagnosed with dilated cardiomyopathy (DCM) exist and are deeply rooted in the history of many societies. The role of social determinants of racial disparities, including racism and bias, is often overlooked in cardiology. DCM incidence is higher in Black subjects; survival and other outcome measures are worse in Black patients with DCM, with fewer referrals for transplantation. DCM in Black patients is underrecognized and under-referred for effective therapies, a consequence of a complex interplay of social and socioeconomic factors. Strategies to manage social determinants of health must be multifaceted and consider changes in policy to expand access to equitable care; provision of insurance, education, and housing; and addressing racism and bias in health care workers. There is an urgent need to prioritize a social justice approach to health care and the pursuit of health equity to eliminate race and other disparities in the management of cardiovascular disease.