Assessment of Cardiac Abnormalities in Sickle Cell Disease Patients Using Cardiac Magnetic Resonance Imaging (CMR)

Introduction Sickle cell disease (SCD) is characterized by chronic hemolytic anemia which predisposes patients to high output heart failure. Recently it has been recognized that repetitive microvascular ischemic insults and reperfusion injury result in diffuse myocardial fibrosis and cardiac remodeling that eventually leads to irreparable myocardial injury. Superimposed on these cardiac insults, patients with SCD often have iron overload related to chronic transfusions. Together, these insults produce a unique SCD-related cardiomyopathy characterized by restrictive physiology with LV dilation. Cardiac Magnetic Resonance Imaging (CMR) is the only non-invasive technique for assessing and quantifying diffuse myocardial fibrosis with simultaneous highly accurate assessment of heart size and systolic and diastolic function. Diffuse myocardial fibrosis is measured by a CMR technique called T1 mapping and calculated as extracellular volume (ECV), which may serve as an early marker of sickle cell related cardiomyopathy. An early marker for SCD-related cardiomyopathy would allow for efficient screening, prevention, and institution of treatment strategies. We describe utilization of CMR to evaluate cardiac pathology in a cohort of pediatric SCD patients. Methods Twenty-six children with SCD underwent CMR, as clinically indicated, between January 2020 and July 2021 at our institution. We analyzed cardiac chamber size (left atrium [LA], left ventricle [LV], right ventricle [RV]), systolic and diastolic function parameters, and quantitative myocardial parametric mapping values (T1 pre- and post-contrast and T2*) for these patients. ECV was calculated for all patients using T1 pre- and post-contrast values in conjunction with current hemoglobin values. Four patients underwent an allogeneic hematopoietic cell transplant (HCT) for SCD and had serial CMR performed before and 1 month after HCT. Results Median age of patients was 17 years; 12 (70%) were female; 22 (84%) had HbSS, 3 (12%) had HbSC and 1 (4%) had Hb S beta thalassemia. 15 (58%) patients had LA enlargement and only a few had ventricular enlargement (LV, 11 [42%]; RV, 9 [35%]). Patients rarely had had LV (4 [15%]) or RV (1 [4%]) systolic dysfunction. Twenty-five (96%) patients had increased ECV; median 30.5% (IQR 28-34%, reference normal 20.8% +/- 2.4). All patients had normal myocardial T2* values indicating no myocardial iron deposition. Additional details are provided in Table. Among those who underwent HCT, all 4 had elevated ECV at baseline, which improved in 1 patient 1-month post-HCT (27% [pre] to 21% [post]). One patient had a dilated LA at baseline with the other 3 developing LA dilation at 1-month post HCT. Conclusion CMR provides accurate and reproducible measurements of chamber sizes/ventricular volumes, myocardial mass, and ventricular function. Multiparametric mapping enabled quantitative evaluation of myocardial fibrosis in patients with SCD. We found that diffuse myocardial fibrosis is often present in children with SCD, even those with apparently normal cardiac function. This indicates damage to the myocardium occurs before symptoms or measurable changes on echocardiography, calling into question our current screening procedures. T1 mapping to monitor the progression of fibrosis could help evaluate response to current therapies including SCD directed therapies, cardioprotective medications, and curative options such as HCT and gene therapy. Hence, we believe that cardiac MRI is complementary to echocardiography and provides additional clinically relevant information that will help guide treatment in patients with SCD. Additionally, it has been shown that patients with SCD who undergo successful HCT exhibit significant improvements in cardiac size, function, and diastolic filling parameters as early as 3 months after the procedure, with improvements continuing slowly up to 1 year after HCT. Early post-HCT evaluation in our cohort did show moderate improvement in ECV in one HCT recipient. Further follow up with serial monitoring is ongoing to evaluate long term changes in these patients. Data on additional patients who have undergone serial CMR monitoring after HCT will be presented at the ASH annual meeting. Figure 1 Figure 1. Disclosures Sharma: CRISPR Therapeutics: Other, Research Funding; Medexus Inc: Consultancy; Spotlight Therapeutics: Consultancy; Novartis: Other: Salary support paid to institution; Vertex Pharmaceuticals/CRISPR Therapeutics: Other: Salary support paid to institution; Vindico Medical Education: Honoraria. Hankins: UpToDate: Consultancy; Global Blood Therapeutics: Consultancy; Vindico Medical Education: Consultancy; Bluebird Bio: Consultancy. Triplett: Miltenyi: Other: Travel, meeting registration.

Sudden Cardiac Death in Systemic Sclerosis: Diagnostics to Assess Risk and Inform Management

Cardiac disease is a leading cause of death in systemic sclerosis (SSc) and sudden cardiac death (SCD) is thought to occur more commonly in SSc than in the general population. Diffuse myocardial fibrosis, myocarditis and ischaemic heart disease are all prevalent in SSc and can be reasonably hypothesised to contribute to an increased risk of SCD. Despite this, SCD remains a relatively understudied area of SSc with little understood about SSc-specific risk factors and opportunities for primary prevention. In this review, we present an overview of the possible mechanisms of SCD in SSc and our current understanding of how each of these mechanisms may contribute to cardiac death. This review highlights the need for a future research agenda that addresses the underlying epidemiology of SCD in SSc and identifies opportunities for intervention to modify the disease course of heart disease in SSc.

Transmethylamine‐N‐Oxide Is Associated With Diffuse Cardiac Fibrosis in People Living With HIV

Background People living with HIV are at increased risk of developing diastolic dysfunction, heart failure, and sudden cardiac death, all of which have been characterized by higher levels of myocardial fibrosis. Transmethylamine‐N‐oxide (TMAO), a dietary gut metabolite, is linked to the development of myocardial fibrosis in animal models. However, it is unclear whether TMAO plays a role in the development of myocardial fibrosis in people living with HIV. Methods and Results The study population consisted of participants enrolled in the multisite cross‐sectional study called CHART‐HIV (Characterizing Heart Function on Anti‐Retroviral Therapy). Participants underwent echocardiography, cardiac magnetic resonance imaging, biomarker analysis, and targeted assessment of gut‐related circulating metabolites; diastolic dysfunction was determined by study‐specific criteria. Multivariable linear regression models were performed to examine the relationship of gut‐related metabolites with serum and imaging measures of myocardial fibrosis. Models were adjusted for traditional cardiovascular, inflammatory, and HIV‐related risk factors. Diastolic dysfunction was present in 94 of 195 individuals (48%) in CHART‐HIV; this cohort demonstrated higher prevalence of hypertension, hyperlipidemia, and chronic kidney disease as well as higher plasma levels of both TMAO and choline. TMAO levels were associated with parameters reflecting increased left ventricular filling pressures and with a marker of the innate immune system. TMAO levels correlated with diffuse myocardial fibrosis ( R =0.35; P <0.05) as characterized by myocardial extracellular volume fraction as well as biomarkers reflective of myocardial fibrosis. Conclusions In this study of people living with HIV, the gut metabolite TMAO was associated with underlying diffuse myocardial fibrosis and found to be a potential marker of early structural heart disease. The mechanistic role of the gut microbiome in HIV‐associated cardiovascular disease warrants further investigation. Registration URL: https://clinicaltrials.gov ; Unique identifier: NCT02860156.

Cardiovascular Magnetic Resonance as Pathophysiologic Tool in Diabetes Mellitus

Diabetes mellitus can independently contribute to cardiovascular disease and represents a severe risk factor for premature development of cardiovascular disease. A three-fold higher mortality than the general population has been observed in type 1 diabetes mellitus whereas a two- to four-fold increased probability to develop cardiovascular disease has been observed in type 2 diabetes mellitus. Cardiovascular magnetic resonance, a non-radiative modality, is superior to all other modalities in detecting myocardial infarction. The main cardiovascular magnetic resonance sequences used include a) balanced steady-state free precession (bSSFP) for function evaluation; b) T2-W for oedema detection; c) T1 W for ischemia detection during adenosine stress; and d) late gadolinium enhanced T1-W images (LGE), evaluated 15 min after injection of paramagnetic contrast agent gadolinium, which permit the diagnosis of replacement fibrosis, which appears white in the middle of suppressed, nulled myocardium. Although LGE is the technique of choice for diagnosis of replacement fibrosis, it cannot assess diffuse myocardial fibrosis. The application of T1 mapping (native or pre contrast and post contrast) allows identification of diffuse myocardial fibrosis, which is not detectable my other means. Native T1 and Contrast-enhanced T1 mapping are involved in the extracellular volume fraction (ECV) calculation. Recently, 1H-cardiovascular magnetic resonance spectroscopy has been applied to calculate the amount of myocardial triglycerides, but at the moment it is not part of the routine assessment of diabetes mellitus. The multifaceted nature of cardiovascular magnetic resonance has the great potential of concurrent evaluation of function and myocardial ischemia/fibrosis in the same examination and represents an indispensable tool for accurate diagnosis of cardiovascular disease in diabetes mellitus.

Diffuse myocardial fibrosis precedes impairment of myocardial strain in patients with systemic sclerosis

Funding Acknowledgements Type of funding sources: None. Background - Myocardial involvement is common in patients with systemic sclerosis (SSc) and causes myocardial fibrosis and subtle ventricular dysfunction. However, the temporal onset of myocardial involvement during the progression of the disease is yet unknown. Purpose - To investigated the presence of subclinical functional impairment and diffuse myocardial fibrosis in patients with very early diagnosis of SSc (VEDOSS) and to compared the findings to patients with established SSc and healthy controls. Methods - 110 SSc patients (86 with established SSc and 24 with VEDOSS) and 15 healthy controls were prospectively recruited. The study subjects underwent cardiovascular magnetic resonance on a clinical 1.5T system. Pre- and post-contrast T1 mapping was performed using a MOLLI (Modified Look-Locker Inversion Recovery) sequence. For extracellular volume (ECV) measurements, a single bolus protocol with image acquisition 15-20 min. post-contrast injection was used. For the assessment of subtle functional impairment, global longitudinal (GLS) and circumferential (GCS) myocardial strain were evaluated. Results - Native T1 values and ECV were elevated in VEDOSS and in patients with established SSc compared to controls (p &lt; 0.001; Figure 1 A & B). GLS was similar in VEDOSS and controls but significantly reduced in patients with established SSc (p &lt; 0.001; Figure 1 C). GCS was similar over all groups (p = 0.88). Patients with clinical evidence of pulmonary or gastrointestinal involvement had higher ECV or T1 values, respectively. Patients with clinical signs of cardiac involvement had lower absolute GLS. SSc subtype, classification or disease duration were not associated with the extent of myocardial fibrosis or impaired strain. Conclusion - Subclinical myocardial involvement first manifests as diffuse myocardial fibrosis identified by expansion of ECV and increased native T1 in VEDOSS patients while subtle functional impairment as measured by GLS only occurs in established SSc. No single clinical feature of SSc shows a strong association with subtle myocardial involvement.

Phase I INSIGHT platform trial: Advanced safety and efficacy data from stratum D evaluating feasibility and safety of eftilagimod alpha (soluble LAG-3 protein) combined with avelumab in advanced solid tumors.

2518 Background: Stratum D of the INSIGHT platform trial evaluates s.c. eftilagimod alpha (efti, IMP321) combined with avelumab in advanced solid tumors. Efti is an MHC class II agonist which activates antigen-presenting cells followed by CD8 T-cell activation. Combination with PD-1/PD-L1 blockade aims at enhanced efficacy. Methods: This IIT platform trial consists of 5 strata: intratumoral (A) or intraperitoneal efti (B); s.c. efti with SOC (C) or with PD-L1 inhibition (D). Strat E is currently under development and starts soon with a new efti combination. This abstract focuses on preliminary data of Strat D. Patients (pts) received 800mg avelumab i.v. q2w along with s.c. efti: 6mg in cohort 1 (coh 1, 6 pts), 30mg in cohort 2 (coh 2, 6 pts). Primary endpoint: safety. Results: Recruitment has been completed with 12 pts (coh 1: gastric, gallbladder, colon cancer, pleural mesothelioma; coh 2: gastric, gastroesophageal, anal, rectum, cervix uteri). No dose limiting toxicities (DLTs) occurred. 10 serious adverse events (SAEs) were reported, none of them considered causally related (4 in 3 pts of coh 1 [1 acute renal insufficiency grade 5 in 1 pt, 2 preileus grade 3 in 1 pt, hearing impaired grade 4 in 1 pt] and 6 in 4 pts of coh 2 [1 anal hemorrhage and 1 gallbladder obstruction in 1 pt, 1 eye pain and 1 surgery to replace the feeding tube in 1 pt, each grade 3, 1 skin infection grade 2, 1 diffuse myocardial fibrosis grade 5]. 1 AE of special interest (AESI) possibly related with avelumab (sarcoidosis grade 1) occurred in coh 1. 2 pts completed max treatment duration with 24 cycles. In coh 1, 47 adverse events (AEs; grade 1-2, 29; grade 3, 14; grade 4, 3; grade 5, 1) occurred in 5 pts. Most common grade 1-2 AEs were nausea, pain in 33%, 33% of the pts. Most common grade 3 AEs were ileus, vomiting in 33%, 33% of the pts. 2 AEs grade 4 (hearing impaired, sepsis) and 1 AE grade 5 (acute renal insufficiency) were reported. All AEs grade 3-5 were considered causally unrelated. In coh 2, 51 adverse events (AEs; grade 1-2, 29; grade 3, 19; grade 4, 2; grade 5, 1) occurred in 5 pts. The most common grade 1-2 AE was hypothyroidism in 33% of the pts. 1 AE grade 5 (diffuse myocardial fibrosis) was reported. Only 1 AE grade 3-5 was considered causally related (urinary tract infection grade 3 related with avelumab). 5 pts showed partial response as best response (2 coh 1: colon, pleural mesothelioma; 3 coh 2: gastric, anal, cervical), 1 stable disease with clinical progression (coh 2) (all but one of these pts still alive), 5 disease progressions acc. to RECIST 1.1 (3 coh 1, 2 coh 2), 1 clinical progression (coh 1). Signals of activity were also observed in pre-treated MSS/PD-L1low pts. Conclusions: Combined treatment with avelumab 800mg and efti 6mg (coh 1) or 30 mg efti (coh 2) seems feasible and safe. No unexpected AEs occurred. Signals of efficacy with CPI combination were seen (DCR 50%). Clinical trial information: NCT03252938.

CMR-Verified Myocardial Fibrosis Is Associated With Subclinical Diastolic Dysfunction in Primary Aldosteronism Patients

ObjectivesThe main cardiac features of primary aldosteronism (PA) are impaired left ventricular (LV) diastolic function, and some articles also reported more cardiac fibrosis in PA patients. However, the correlation between LV dysfunction and diffuse myocardial fibrosis in PA remains unknown.MethodsWe enrolled 84 PA patients and 28 essential hypertension (EH) patients in West China Hospital. Cardiac magnetic resonance imaging (CMR) contrast enhancement was arranged for all subjects. Postcontrast T1 time and left ventricular myocardial strains and strain rates were measured.Results76 PA patients and 27 essential hypertension (EH) patients were included in the final analysis. Blood pressure, LV mass indexes, and LV ejection fractions were comparable in both groups, while the global circumferential peak diastolic strain rate (PDSR) was lower (0.9 ± 0.3 vs. 1.1 ± 0.4, p &lt;0.01) and the postcontrast T1 time was shorter (520 ± 38 vs. 538 ± 27, p = 0.01) in PA patients than those in EH patients. Postcontrast T1 time (p = 0.01) was independently related to global circumferential PDSR after adjusting for age and duration of hypertension in PA patients. Furthermore, plasma aldosterone concentration was negatively associated with postcontrast T1 time (R = −0.253, p = 0.028) in PA patients.ConclusionsThe global circumferential PDSR derived by CMR is decreased, and the diffuse myocardial fibrosis is increased in PA patients compared to those in blood pressure matched EH patients. The severity of cardiac diastolic dysfunction independently relates to the degree of diffuse myocardial fibrosis in PA patients, and the diffuse myocardial fibrosis may be caused by high PAC level.Clinical Trial Registrationhttp://www.chictr.org.cn/listbycreater.asp, identifier ChiCTR2000031792.