Genetic Architecture of Dilated Cardiomyopathy in Individuals of African and European Ancestry.

Importance: Black patients with dilated cardiomyopathy (DCM) have increased familial risk and worse outcomes than White patients, but most DCM genetic data are from White patients. Objective: To compare the rare variant genetic architecture of DCM by genomic ancestry within a diverse population of patients with DCM. Design: Cross-sectional study enrolling patients with DCM who self-identified as non-Hispanic Black, Hispanic, or non-Hispanic White from June 7, 2016, to March 15, 2020, at 25 US advanced heart failure programs. Variants in 36 DCM genes were adjudicated as pathogenic, likely pathogenic, or of uncertain significance. Exposure: Presence of DCM. Main Outcomes and Measures: Variants in DCM genes classified as pathogenic/likely pathogenic/uncertain significance and clinically actionable (pathogenic/likely pathogenic). Results: A total of 505, 667, and 26 patients with DCM of predominantly African, European, or Native American genomic ancestry, respectively, were included. Compared with patients of European ancestry, a lower percentage of patients of African ancestry had clinically actionable variants (8.2% [95% CI, 5.2%-11.1%] vs 25.5% [95% CI, 21.3%-29.6%]), reflecting the lower odds of a clinically actionable variant for those with any pathogenic variant/likely pathogenic variant/variant of uncertain significance (odds ratio, 0.25 [95% CI, 0.17-0.37]). On average, patients of African ancestry had fewer clinically actionable variants in TTN (difference, -0.09 [95% CI, -0.14 to -0.05]) and other genes with predicted loss of function as a disease-causing mechanism (difference, -0.06 [95% CI, -0.11 to -0.02]). However, the number of pathogenic variants/likely pathogenic variants/variants of uncertain significance was more comparable between ancestry groups (difference, -0.07 [95% CI, -0.22 to 0.09]) due to a larger number of non-TTN non-predicted loss of function variants of uncertain significance, mostly missense, in patients of African ancestry (difference, 0.15 [95% CI, 0.00-0.30]). Published clinical case-based evidence supporting pathogenicity was less available for variants found only in patients of African ancestry (P < .001). Conclusion and Relevance: Patients of African ancestry with DCM were less likely to have clinically actionable variants in DCM genes than those of European ancestry due to differences in genetic architecture and a lack of representation of African ancestry in clinical data sets.

Rare Variant Genetics and Dilated Cardiomyopathy Severity: The DCM Precision Medicine Study.

BACKGROUND: Dilated cardiomyopathy (DCM) can lead to advanced disease, defined herein as necessitating a durable left ventricular assist device or a heart transplant (LVAD/HT). DCM is known to have a genetic basis, but the association of rare variant genetics with advanced DCM has not been studied. METHODS: We analyzed clinical and genetic sequence data from patients enrolled between 2016 and 2021 in the US multisite DCM Precision Medicine Study, which was a geographically diverse, multiracial, multiethnic cohort. Clinical evaluation included standardized patient interview and medical record query forms. DCM severity was classified into 3 groups: patients with advanced disease with LVAD/HT; patients with an implantable cardioverter defibrillator (ICD) only; or patients with no ICD or LVAD/HT. Rare variants in 36 DCM genes were classified as pathogenic or likely pathogenic or variants of uncertain significance. Confounding factors we considered included demographic characteristics, lifestyle factors, access to care, DCM duration, and comorbidities. Crude and adjusted associations between DCM severity and rare variant genetic findings were assessed using multinomial models with generalized logit link. RESULTS: Patients' mean (SD) age was 51.9 (13.6) years; 42% were of African ancestry, 56% were of European ancestry, and 44% were female. Of 1198 patients, 347 had LVAD/HT, 511 had an ICD, and 340 had no LVAD/HT or ICD. The percentage of patients with pathogenic or likely pathogenic variants was 26.2%, 15.9%, and 15.0% for those with LVAD/HT, ICD only, or neither, respectively. After controlling for sociodemographic characteristics and comorbidities, patients with DCM with LVAD/HT were more likely than those without LVAD/HT or ICD to have DCM-related pathogenic or likely pathogenic rare variants (odds ratio, 2.3 [95% CI, 1.5-3.6]). The association did not differ by ancestry. Rare variant genetic findings were similar between patients with DCM with an ICD and those without LVAD/HT or ICD. CONCLUSIONS: Advanced DCM was associated with higher odds of rare variants in DCM genes adjudicated as pathogenic or likely pathogenic, compared with individuals with less severe DCM. This finding may help assess the risk of outcomes in management of patients with DCM and their at-risk family members. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03037632.

Screening for Dilated Cardiomyopathy in At-Risk First-Degree Relatives.

BACKGROUND: Cardiovascular screening is recommended for first-degree relatives (FDRs) of patients with dilated cardiomyopathy (DCM), but the yield of FDR screening is uncertain for DCM patients without known familial DCM, for non-White FDRs, or for DCM partial phenotypes of left ventricular enlargement (LVE) or left ventricular systolic dysfunction (LVSD). OBJECTIVES: This study examined the yield of clinical screening among reportedly unaffected FDRs of DCM patients. METHODS: Adult FDRs of DCM patients at 25 sites completed screening echocardiograms and ECGs. Mixed models accounting for site heterogeneity and intrafamilial correlation were used to compare screen-based percentages of DCM, LVSD, or LVE by FDR demographics, cardiovascular risk factors, and proband genetics results. RESULTS: A total of 1,365 FDRs were included, with a mean age of 44.8 ± 16.9 years, 27.5% non-Hispanic Black, 9.8% Hispanic, and 61.7% women. Among screened FDRs, 14.1% had new diagnoses of DCM (2.1%), LVSD (3.6%), or LVE (8.4%). The percentage of FDRs with new diagnoses was higher for those aged 45 to 64 years than 18 to 44 years. The age-adjusted percentage of any finding was higher among FDRs with hypertension and obesity but did not differ statistically by race and ethnicity (16.2% for Hispanic, 15.2% for non-Hispanic Black, and 13.1% for non-Hispanic White) or sex (14.6% for women and 12.8% for men). FDRs whose probands carried clinically reportable variants were more likely to be identified with DCM. CONCLUSIONS: Cardiovascular screening identified new DCM-related findings among 1 in 7 reportedly unaffected FDRs regardless of race and ethnicity, underscoring the value of clinical screening in all FDRs.

Effectiveness of the Family Heart Talk Communication Tool in Improving Family Member Screening for Dilated Cardiomyopathy: Results of a Randomized Trial.

BACKGROUND: Managing disease risk among first-degree relatives of probands diagnosed with a heritable disease is central to precision medicine. A critical component is often clinical screening, which is particularly important for conditions like dilated cardiomyopathy (DCM) that remain asymptomatic until severe disease develops. Nonetheless, probands are frequently ill-equipped to disseminate genetic risk information that motivates at-risk relatives to complete recommended clinical screening. An easily implemented remedy for this key issue has been elusive. METHODS: The DCM Precision Medicine Study developed Family Heart Talk, a booklet designed to help probands with DCM communicate genetic risk and the need for cardiovascular screening to their relatives. The effectiveness of the Family Heart Talk booklet in increasing cardiovascular clinical screening uptake among first-degree relatives was assessed in a multicenter, open-label, cluster-randomized, controlled trial. The primary outcome measured in eligible first-degree relatives was completion of screening initiated within 12 months after proband enrollment. Because probands randomized to the intervention received the booklet at the enrollment visit, eligible first-degree relatives were limited to those who were alive the day after proband enrollment and not enrolled on the same day as the proband. RESULTS: Between June 2016 and March 2020, 1241 probands were randomized (1:1) to receive Family Heart Talk (n=621) or not (n=620) within strata defined by site and self-identified race/ethnicity (non-Hispanic Black, non-Hispanic White, or Hispanic). Final analyses included 550 families (n=2230 eligible first-degree relatives) in the Family Heart Talk arm and 561 (n=2416) in the control arm. A higher percentage of eligible first-degree relatives completed screening in the Family Heart Talk arm (19.5% versus 16.0%), and the odds of screening completion among these first-degree relatives were higher in the Family Heart Talk arm after adjustment for proband randomization stratum, sex, and age quartile (odds ratio, 1.30 [1-sided 95% CI, 1.08-∞]). A prespecified subgroup analysis did not find evidence of heterogeneity in the adjusted intervention odds ratio across race/ethnicity strata (P=0.90). CONCLUSIONS: Family Heart Talk, a booklet that can be provided to patients with DCM by clinicians with minimal additional time investment, was effective in increasing cardiovascular clinical screening among first-degree relatives of these patients. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03037632.

Prevalence and Cumulative Risk of Familial Idiopathic Dilated Cardiomyopathy.

Importance: Idiopathic dilated cardiomyopathy (DCM) aggregates in families, and early detection in at-risk family members can provide opportunity to initiate treatment prior to late-phase disease. Most studies have included only White patients, yet Black patients with DCM have higher risk of heart failure-related hospitalization and death. Objective: To estimate the prevalence of familial DCM among DCM probands and the age-specific cumulative risk of DCM in first-degree relatives across race and ethnicity groups. Design, Setting, and Participants: A family-based, cross-sectional study conducted by a multisite consortium of 25 US heart failure programs. Participants included patients with DCM (probands), defined as left ventricular systolic dysfunction and left ventricular enlargement after excluding usual clinical causes, and their first-degree relatives. Enrollment commenced June 7, 2016; proband and family member enrollment concluded March 15, 2020, and April 1, 2021, respectively. Exposures: The presence of DCM in a proband. Main Outcomes and Measures: Familial DCM defined by DCM in at least 1 first-degree relative; expanded familial DCM defined by the presence of DCM or either left ventricular enlargement or left ventricular systolic dysfunction without known cause in at least 1 first-degree relative. Results: The study enrolled 1220 probands (median age, 52.8 years [IQR, 42.4-61.8]; 43.8% female; 43.1% Black and 8.3% Hispanic) and screened 1693 first-degree relatives for DCM. A median of 28% (IQR, 0%-60%) of living first-degree relatives were screened per family. The crude prevalence of familial DCM among probands was 11.6% overall. The model-based estimate of the prevalence of familial DCM among probands at a typical US advanced heart failure program if all living first-degree relatives were screened was 29.7% (95% CI, 23.5% to 36.0%) overall. The estimated prevalence of familial DCM was higher in Black probands than in White probands (difference, 11.3% [95% CI, 1.9% to 20.8%]) but did not differ significantly between Hispanic probands and non-Hispanic probands (difference, -1.4% [95% CI, -15.9% to 13.1%]). The estimated prevalence of expanded familial DCM was 56.9% (95% CI, 50.8% to 63.0%) overall. Based on age-specific disease status at enrollment, estimated cumulative risks in first-degree relatives at a typical US advanced heart failure program reached 19% (95% CI, 13% to 24%) by age 80 years for DCM and 33% (95% CI, 27% to 40%) for expanded DCM inclusive of partial phenotypes. The DCM hazard was higher in first-degree relatives of non-Hispanic Black probands than non-Hispanic White probands (hazard ratio, 1.89 [95% CI, 1.26 to 2.83]). Conclusions and Relevance: In a US cross-sectional study, there was substantial estimated prevalence of familial DCM among probands and modeled cumulative risk of DCM among their first-degree relatives. Trial Registration: ClinicalTrials.gov Identifier: NCT03037632.

Torrential Mitral Regurgitation After Transcatheter Edge-to-Edge Mitral Valve Repair.

A patient with severe mitral regurgitation and chronic systolic heart failure taking inotropic support at home presents for transcatheter edge-to-edge mitral valve repair, complicated by torrential mitral regurgitation from damaged mitral leaflets requiring escalating mechanical circulatory support and ultimately expedited orthotopic heart transplantation. (Level of Difficulty: Intermediate.).

The Limitations of Symptom-based Heart Failure Management.

Heart failure (HF) has emerged as a global epidemic and it affects about 6 million adults in the US. HF medical treatment, as recommended in guidelines, significantly improves survival and quality of life; however, the mortality burden of HF remains high. For decades, treatment has been guided, mainly by symptoms, leading to undertreatment in a range of settings. Current evidence emphasises the unfavourable outcomes of HF even in early stages or in patients who achieve reverse remodeling and remission or recovery under optimised treatment. This should stimulate efforts towards a more objective, rigorous management, covering the entire spectrum of mild, moderate and severe HF.

Combined analysis of allograft inflammatory factor-1, interleukin-18, and Toll-like receptor expression and association with allograft rejection and coronary vasculopathy.

In cardiac transplantation settings, the initial myocardial ischemia and reperfusion may cause myocyte tissue injury and the release of allograft inflammatory factor-1 (AIF-1). This in part may trigger the innate immune response through the modulation of Toll-like receptor-2 (TLR-2) and AIF-1 expression and function, causing the release of proinflammatory cytokines. The goal was to demonstrate these markers in the peripheral blood and biopsy specimen from recipients with cardiac allograft rejection and coronary vasculopathy (CV). Peripheral blood and endomyocardial specimens were tested by reverse transcriptase-polymerase chain reaction and immunohistochemistry stains for identification of TLR-2, -4, interleukin-18, and AIF-1 markers and analyzed against clinical rejection grades for rejection. The differences for mRNA transcript levels were determined by one-way analysis of variance. The mRNA expression levels were significantly varied for TLR-2 in monocytes with different rejection grades (P < 0.0001). The mean +/- SEM level of mRNA expression for 3A grade rejection was 64.21 +/- 3.8; grade 1A, 38.4 +/- 3.5; and for Grade 0 was 38.46 +/- 2.8. The TLR-4 mRNA expression was increased but the specificity was not statistically significant. The TLR-2 immunoreactivity was strongly detected in infiltrating mononuclear cells and cardiac myocytes in Grade 3A rejection. AIF-1 expression was increased significantly in the group with 3A rejection and Grade III CV as compared with Grade 0 or 1A. Interleukin-18 receptors were strongly detected in Grade 3A rejection and CV. The expression profiles of AIF-1, TLR-2, and interleukin-18 were correlated with biopsy-proven allograft rejection in both peripheral blood and local tissue, suggesting a potential for diagnostic biomarkers for early detection of allograft rejection.

Tamponade precedes diagnosis of systemic lupus erythematosus.

The most common cardiovascular manifestation of Systemic Lupus Erythematosus is pericardial disease. Tamponade in SLE is rarely described. The patient discussed in this case report presented with symptoms of heart failure. Physical exam, laboratory testing, echocardiography, and right heart catheterization revealed multiple morbid conditions including tamponade. The diagnoses satisfied four criteria for the classification of SLE. This case emphasizes the importance of a thorough physical exam in guiding diagnostic and therapeutic measures.

Frequency distribution of cytochrome P450 3A4 gene polymorphism in ethnic populations and in transplant recipients.

CYP 3A4 plays a vital role in the metabolism of many drugs including immunosuppressants. An association between a transition of A --> G at position -290 of the 5'-regulatory region of the CYP 3A4 gene and an effect on the level of transcription has been reported. The CYP 3A4-G variant frequency varies substantially in different populations. In addition it has been demonstrated in association with several disease conditions, including clinical grades of prostate cancer, breast cancer, secondary leukemia, hypercholesterolemia and diabetes. We sought to determine the frequency distributions, in African American (AFAM) and Caucasian (CAU) populations as well as patients with multiple complex diseases, such as those that had undergone cardiac or renal transplantation. Sequence-specific primers and PCR were used to determine genotype variation in 206 AFAM and 108 CAU individuals. CYP 3A4-G genotype was present with a higher frequency in AFAM individuals as compared with CAU (83% vs. 3%, p < 0.0001, RR = 3.9). The homozygous AA allele was predominantly present in CAU (97%) but only 17% in AFAM (p < 0.0001, RR = 2.5). In contrast, the homozygous GG allele was only detected in AFAM group (14.6%). The frequency distribution of homozygous GG and AA alleles were inversely present in male vs. female patients with CTx or RTx. Pre-transplantation clinical conditions demonstrated that hypertension (HTN), hyperlipidemia and to a lesser extent diabetes (DM) were present in CTx and RTx patients with homozygous GG alleles. In addition, 75% of AFAM patients with homozygous GG genotype experienced multiple rejection episodes with severity grades of 3A after cardiac transplantation, and 31.5% of homozygous GG patients with RTx suffered from rejections (p < 0.05; RR = 2.4). In conclusion, CYP 3A4 genotype demonstrated a remarkable interindividual variation between AFAM and CAU populations, and furthermore CTx patients with homozygous GG genotype were at higher risk of developing rejection as compared with RTx patients. This indicates an underlying heterogeneity with regard to the disease characteristics as well as the therapy regimen.

Induction of oxidative stress and disintegrin metalloproteinase in human heart end-stage failure.

Collagen degradation is required for the creation of new integrin binding sites necessary for cell survival. However, a complete separation between the matrix and the cell leads to apoptosis, dilatation, and failure. Previous studies have demonstrated increased metalloproteinase activity in the failing myocardium. To test the hypothesis that disintegrin metalloproteinase (DMP) is induced in human heart end-stage failure, left ventricle tissue from ischemic cardiomyopathic (ICM, n = 10) and dilated cardiomyopathic (DCM, n = 10) human hearts were obtained at the time of orthotopic cardiac transplant. Normal (n = 5) tissue specimens were obtained from unused hearts. The levels of reduced oxygen species (ROS) were 12 +/- 2, 25 +/- 3, and 16 +/- 2 nmol (means +/- SE, P < 0.005) in normal, ICM, and DCM, respectively, by spectrofluorometry. The percent levels of endothelial cells were 100 +/- 15, 35 +/- 19, and 55 +/- 11 in normal, ICM, and DCM, respectively, by CD31 labeling. The levels of nitrotyrosine by Western analysis were significantly increased, and endothelial nitric oxide (NO) by the Griess method was decreased in ICM and DCM compared with normal tissue. The synthesis and degradation of beta(1)-integrin and connexin 43 were significantly increased in ICM and DCM compared with normal hearts by Western analysis. Levels of DMP were increased, and levels of cardiac inhibitor of metalloproteinase (CIMP) were decreased. Aggrecanase activity of DMP was significantly increased in ICM and DCM hearts compared with normal. These results suggest that the occurrence of cardiomyopathy is significantly confounded by the increase in ROS, nitrotyrosine, and DMP activity. This increase is associated with decreased NO, endothelial cell density, and CIMP. In vitro, treatment of CIMP abrogated the DMP activity. The treatment with CIMP may prevent degradation of integrin and connexin and ameliorate heart failure.