Citations

Abstract Background and Aims Truncating variants in the TTN gene (TTNtv) are the most common genetic cause of dilated cardiomyopathy (DCM) but also occur as incidental findings in the general population. This study investigated factors associated with the clinical manifestation of TTNtv. Methods An international multicentre retrospective observational study was performed in families with TTNtv-related DCM. Shared frailty models were used to estimate associations of variant characteristics with lifetime risk of DCM, and logistic regression to estimate odds ratios (ORs) for individual-level clinical risk factor profiles (cardiac conditions, cardiovascular comorbidities, lifestyle) and DCM. Results A total of 3158 subjects in 1043 families with TTNtv-related DCM were studied. TTNtv-positive subjects were 21-fold more likely to develop DCM [OR, 21.21; 95% confidence interval (CI), 14.80–30.39]. Disease onset was earlier in males, but was similar for TTNtv of different types and locations. The presence of clinical risk factors was associated with earlier DCM onset (OR, 3.41; 95% CI, 2.06–5.64), with a prior history of atrial fibrillation having a two-fold increased odds of DCM (OR, 2.05; 95% CI, 1.27–3.32). The prevalence of clinical risk factors increased with age; however, the strength of the DCM association was greatest for young-onset (<30 years) disease (OR, 4.75; 95% CI, 2.35–9.60). Administration of beta-adrenergic receptor or renin-angiotensin system-blocking drugs prior to overt DCM was associated with 87% reduced odds of DCM (OR, .13; 95% CI, .08–.23). Conclusions Disease onset in TTNtv-associated familial DCM is dependent on individual patient context and is potentially modifiable by risk factor management and prophylactic therapeutic intervention.

Introduction: Atherosclerotic peripheral artery disease (PAD) leads to a great burden of cardiovascular and limb-related morbidity and mortality in African Americans (AA) compared to White Americans. Medical center partnerships with churches may be an effective method to improve PAD awareness and detection in the AA community. Hypotheses: We hypothesized that implementing a medical educational program in partnership with churches would increase PAD familiarity and identify participants with undiagnosed PAD. Aims: To determine (1) PAD familiarity before and after a one-time educational intervention and (2) the prevalence of PAD in older, church-going Nashville residents. Methods: Using a community-engaged research (CER) model, we partnered with 5 churches to enroll participants ≥ 50 years of age. Participants were given a 16-point pre- and post-educational program assessment to determine baseline and post-intervention PAD knowledge. Pre- and post-intervention scores were compared using Wilcoxon signed-rank test. Ankle-brachial index (ABI) testing was used to screen for PAD (ABI < 0.9). Results: We enrolled 120 participants (mean age [SD]: 64.67 [8.33] years, 74% women, 80% AA). The prevalence of PAD was 10.83%. Pre-intervention PAD awareness was low (mean score (MS): 10.89 [4.24]) and improved significantly post-intervention in all participants (MS: 13.88 [2.76; p=2 x 10 -12 ). Participants without PAD (ABI ≥ 0.9-1.39) (MS: 10.81 [4.28] vs. 13.91 [2.79]; p= p=4 x 10 -11 ) and with indeterminate status (ABI>1.4) (MS [SD]: 10.00 [5.03] vs. 14.10 [1.73; p=0.01) showed significant improvement in PAD awareness pre vs post intervention. Participants with PAD (ABI <0.9) (MS: 12.15 [3.26] vs. 13.46 [3.26; p=0.40) did not have significant improvement in their awareness scores. Conclusions: The PRAISE study demonstrates an effective CER partnership with churches as a method to increase PAD awareness and early detection of PAD, specifically among AAs.

Background Cardio-ankle vascular index (CAVI) is a measure of arterial stiffness associated with cardiovascular (CV) events and mortality. African American (AA) adults have a higher prevalence of CV risk factors (RFs) and adverse social determinants of health (SDOH) leading to a higher CV mortality risk than White adults. These disparities may be associated with arterial stiffness, however limited research exists on the association of CV RFs, SDOH, and CAVI among AAs. Hypotheses We hypothesized that CV RFs (eg, diabetes) and SDOH (eg, income) would be associated with CAVI among AA adults. Our secondary hypothesis was that AA adults would have a higher prevalence of abnormal CAVI scores (≥8.0) than White adults. Methods In the FAITH! HH+ study, CAVI measurements, CV RFs, and SDOH surveys were obtained. We collected CAVI readings and CV RFs from a secondary cohort of White adults (n=600), referred for echocardiography and without structural cardiac disease. The association of CV RFs, SDOH and CAVI scores among AAs was assessed via ANOVA and univariable linear regression. We compared CV RFs among both cohorts using Chi-squared tests and ANOVA, followed by comparing CAVI scores between cohorts using a multivariable linear regression model. Results In total, 48 AAs were included from the FAITH! HH+ cohort (mean age [SD]: 54.2 [11.5] years, 67.4% women). There was no significant association between CV RFs or SDOH with CAVI scores. In the 600 White adults assessed, mean age was 59.5 [14.7] years and 45.7% were women. Compared to White adults, AA participants had a lower burden of hyperlipidemia (43.5% vs 61.4%; p=0.017), but a higher burden of hypertension (73.9% vs 57.7%; p=0.031), diabetes (28.3% vs 9.3%; p<0.001), and obesity (71.7% obese vs 36.0%; p<0.001). There was no significant difference in CAVI scores between groups when adjusted for age, sex, and CV RFs (AA cohort: mean: 8.0 [1.4] vs White cohort: 8.4 [1.5]; p=0.790). Conclusions In this pilot study, SDOH and CV RFs were not associated with CAVI scores among AAs. There was no significant difference in CAVI scores between AA and White adults, despite a significantly higher burden of CV RFs in the AA cohort. Further studies are warranted to identify factors linked with onset and progression of arterial stiffness among AAs.

Background: The study of hypertrophic cardiomyopathy (HCM) can yield insight into the mechanisms underlying the complex trait of cardiac hypertrophy. To date, most genetic variants associated with HCM have been found in sarcomeric genes. Here, we describe a novel HCM-associated variant in the noncanonical Wnt signaling interactor WTIP (Wilms tumor interacting protein) and provide evidence of a role for WTIP in complex disease. Methods: In a family affected by HCM, we used exome sequencing and identity-by-descent analysis to identify a novel variant in WTIP (p.Y233F). We knocked down WTIP in isolated neonatal rat ventricular myocytes with lentivirally delivered short hairpin ribonucleic acids and in Danio rerio via morpholino injection. We performed weighted gene coexpression network analysis for WTIP in human cardiac tissue, as well as association analysis for WTIP variation and left ventricular hypertrophy. Finally, we generated induced pluripotent stem cell–derived cardiomyocytes from patient tissue, characterized size and calcium cycling, and determined the effect of verapamil treatment on calcium dynamics. Results: WTIP knockdown caused hypertrophy in neonatal rat ventricular myocytes and increased cardiac hypertrophy, peak calcium, and resting calcium in D rerio . Network analysis of human cardiac tissue indicated WTIP as a central coordinator of prohypertrophic networks, while common variation at the WTIP locus was associated with human left ventricular hypertrophy. Patient-derived WTIP p.Y233F-induced pluripotent stem cell–derived cardiomyocytes recapitulated cellular hypertrophy and increased resting calcium, which was ameliorated by verapamil. Conclusions: We demonstrate that a novel genetic variant found in a family with HCM disrupts binding to a known Wnt signaling protein, misregulating cardiomyocyte calcium dynamics. Further, in orthogonal model systems, we show that expression of the gene WTIP is important in complex cardiac hypertrophy phenotypes. These findings, derived from the observation of a rare Mendelian disease variant, uncover a novel disease mechanism with implications across diverse forms of cardiac hypertrophy.