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In the EXPLORER-HCM trial, mavacamten improved exercise capacity and symptoms in patients with obstructive hypertrophic cardiomyopathy (oHCM). Mavacamten effects on the primary endpoint, a composite of peak oxygen consumption (VOSubgroup analyses by beta-blocker use were performed in patients with oHCM from the EXPLORER-HCM and mavacamten long-term extension (MAVA-LTE) studies. In EXPLORER-HCM, 189 patients (75.3%) were receiving beta-blockers, and 62 (24.7%) were receiving non-dihydropyridine calcium-channel blockers or no background HCM medication; 170 patients (90.4%) receiving beta-blockers had chronotropic incompetence. Improvements in peak VOMavacamten improved measures of functional capacity, LVOT obstruction, symptom burden and biomarkers in patients with HCM regardless of beta-blocker use. Beta-blocker use was often associated with chronotropic incompetence, affecting peak VO

What is this plain language summary about? This plain language summary describes the results of a study looking at the effects of a medicine called ARRY-371797 (also known as PF-07265803) in people with dilated cardiomyopathy (DCM for short) caused by a faulty LMNA gene. This condition is called LMNA-related DCM. DCM happens when the heart becomes bigger and weaker than normal, impacting functional capacity and leading to symptoms of heart failure. This means the heart is not able to pump blood around the body as easily, and people are unable to do as much in their daily lives (like getting dressed and going shopping). People may inherit a faulty LMNA gene from one of their parents, or a faulty LMNA gene may develop when mistakes happen during cell growth and replication. ARRY-371797 targets a specific mechanism in the body that can lead to heart problems in people with a faulty LMNA gene. As ARRY-371797 is not currently approved for use outside of clinical trials, it doesn't currently have an easily recognizable trade name. What were the results? 12 American people (average age 50 years) with LMNA-related DCM took part in the study and received 400 mg or 100 mg of ARRY-371797 twice daily for 48 weeks. People knew which dose of ARRY-371797 they were taking. People were checked after 4, 12, 24, 36 and 48 weeks of taking ARRY-371797 to see how far they could walk in the 6-minute walk test (6MWT for short). The level of NT-proBNP in their blood was also measured. NT-proBNP is a biomarker used to measure the severity of heart failure. A biomarker is something found in the body that can be measured to indicate the extent of a disease. - After taking ARRY-371797 for 12 weeks, people were able to walk further in the 6MWT and had lower levels of NT-proBNP in their blood. This suggests improvement in functional capacity (exercise tolerance) and heart function. Researchers also asked people about their quality of life using the Kansas City Cardiomyopathy Questionnaire (KCCQ for short), and looked for any side effects. - Researchers saw some improvement in KCCQ scores. - Researchers saw no major side effects that they considered to be related to ARRY-371797 treatment. A side effect is something that people feel was caused by a medicine or treatment. Overall, this study showed that people with LMNA-related DCM who took ARRY-371797 had improved functional capacity (exercise tolerance), improved heart function, and improved quality of life. Phase 2 study ( NCT02057341 ) Phase 2 long-term extension study ( NCT02351856 ) Phase 3 REALM-DCM study ( NCT03439514 )

Summary Introduction Inducible laryngeal obstruction is a common and challenging cause of exertional dyspnea. We report a case of an unanticipated cardiac condition that presented with symptoms suggestive of inducible laryngeal obstruction. Discussion A 55-year-old man was evaluated for progressive exertional dyspnea and throat tightness, unexplained after multiple medical evaluations. Resting laryngeal examination was suspicious for laryngopharyngeal reflux and mild vocal fold adduction during quiet expiration. Given progressive and refractory symptoms, maximal cardiopulmonary exercise testing with intermittent laryngeal examination was performed. This study excluded laryngeal causes of exercise limitation and led to an unexpected diagnosis of persistent atrial flutter and hypertrophic cardiomyopathy. Conclusion Cardiopulmonary exercise testing with laryngeal examination can identify unexpected and life-threatening mimics of inducible laryngeal obstruction that may be missed by unmonitored exercise challenges. Suspicion for inducible laryngeal obstruction at rest may not predict the true nature of exercise limitation on cardiopulmonary exercise testing.

BACKGROUND: The development of left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM) is rare but serious and associated with poor outcomes in adults. Little is known about the prevalence, predictors, and prognosis of LVSD in patients diagnosed with HCM as children. METHODS: Data from patients with HCM in the international, multicenter SHaRe Registry (Sarcomeric Human Cardiomyopathy) were analyzed. LVSD was defined as left ventricular ejection fraction RESULTS: We studied 1010 patients diagnosed with HCM during childhood ( CONCLUSIONS: Patients with childhood-diagnosed HCM have a significantly higher lifetime risk of developing LVSD, and LVSD emerges earlier than for patients with adult-diagnosed HCM. Regardless of age at diagnosis with HCM or LVSD, the prognosis with LVSD is poor, warranting careful surveillance for LVSD, especially as children with HCM transition to adult care.

First-degree relatives of a proband with an inherited cardiac condition (ICC) are offered predictive genetic testing for the pathogenic or likely pathogenic (P/LP) cardiac gene variant (CGV) to clarify their risk for the familial condition. Relatives who test negative for a familial P/LP CGV typically do not require longitudinal cardiac surveillance. To our knowledge, no previous study has investigated adjustment to risk reduction and subsequent screening practices in genotype-negative relatives from an ICC population. We thus investigated risk perception and ongoing screening practices in genotype-negative adults who received cardiac genetic counseling. Correlations between clinical and demographic variables and risk perception and screening practices were also investigated. On average, participants (n = 71) reported a perceived 19.5% lifetime risk of developing the ICC in their family, despite their negative genetic test result. The majority (54%) of participants reported having undergone cardiac screening after disclosure of their negative result. There were no significant correlations between clinical and demographic variables and risk perception or screening practices. Furthermore, risk perception was not found to impact the likelihood of cardiac screening. These findings suggest that even with comprehensive cardiac genetic counseling, a proportion of this population did not accurately comprehend or recall their cardiac disease risk. Additional interventions beyond traditional result disclosure should be explored to help genotype-negative individuals adjust to their reduction in risk for a familial ICC.

Background: Lamin A/C gene ( LMNA )-related dilated cardiomyopathy is a serious and life-threatening condition with a high unmet medical need. This phase 2 study assessed the effects of the oral selective p38 mitogen-activated protein kinase inhibitor ARRY-371797 on functional capacity and cardiac function in patients with LMNA -related dilated cardiomyopathy. Methods: Patients with LMNA -related dilated cardiomyopathy in New York Heart Association class II–IIIA, on background heart failure treatment, received ARRY-371797 100 or 400 mg twice daily for 48 weeks. The primary end point was change from baseline in the 6-minute walk test distance at 12 weeks. Secondary end points included changes over time in 6-minute walk test distance, NT-proBNP (N-terminal pro-B-type natriuretic peptide) concentration, left ventricular ejection fraction, and quality-of-life scores on the Kansas City Cardiomyopathy Questionnaire. Data from the 2 dose groups were combined. Results: Twelve patients were enrolled; median (minimum, maximum) 6-minute walk test distance at baseline was 314 (246, 412) m. At week 12, the mean (80% CI) increase from baseline in 6-minute walk test distance was 69 (39, 100) m (median, 47 m). Median NT-proBNP concentration declined from 1409 pg/mL at baseline to 848 pg/mL at week 12. Mean left ventricular ejection fraction was stable at week 12. There was a trend toward improvement in Kansas City Cardiomyopathy Questionnaire Overall and Clinical Summary scores at week 12. No clinically significant drug-related safety concerns were identified. Conclusions: ARRY-371797 was well tolerated and resulted in potential increases in functional capacity and lower concentrations of cardiac biomarker NT-proBNP in patients with LMNA -related dilated cardiomyopathy. Registration: URL: https://clinicaltrials.gov ; Unique identifier: NCT02057341.

Background: In Lamin A/C ( LMNA ) cardiomyopathy, atrial fibrillation (AF) commonly occurs before dilated cardiomyopathy, and the ability to predict its incidence is limited. We hypothesized that left atrial (LA) echocardiographic phenotyping can identify atrial myopathy and harbingers of AF. Methods: Echocardiograms from patients with pathogenic or likely pathogenic variants in LMNA (n=77) with and without reduced left ventricular ejection fraction (LVEF, (TTNtv ) (n=35) with similar LVEF, sex, and age distributions. Echocardiographic analysis, blinded to genotype, included strain and volumetric measures of left ventricular and atrial function. The primary outcome was incident AF. Results: At baseline, 43% of the patients with pathogenic or likely pathogenic LMNA variants had a history of AF, including 26% of those with LVEF ≥50%. Compared with healthy subjects, the patients with pathogenic or likely pathogenic LMNA variants and LVEF ≥50% had reduced LA contractile strain ( LMNA , 11.8±6.1% versus control, 15.0±4.2%; P =0.003). Compared to LVEF-matched ( TTNtv ) patients, the patients with pathogenic or likely pathogenic LMNA variants and LVEF P =0.02). Over a median follow-up of 2.8 (1.2–5.7) years, LA contractile strain was the only significant predictor of AF in multivariable Cox regression (hazard ratio, 4.0 [95% CI, 1.04–15.2]). Conclusions: LMNA cardiomyopathy is associated with early intrinsic atrial myopathy reflected by high AF prevalence and reduced LA contractile strain, even in the absence of LV dysfunction and LA dilation. Whether LA strain can be used as a monitoring strategy to detect and mitigate AF complications requires validation.

As the acuity, complexity, and illness severity of patients admitted to cardiac intensive care units have increased, the need to recognize critical care cardiology (CCC) as a dedicated subspecialty in cardiovascular disease has received increasing support. Differing viewpoints exist regarding the optimal pathway for CCC training. Currently, all proposed CCC training pathways involve permutations of individual training years culminating in subspecialty certification across multiple disciplines; however, there are significant disadvantages to these training paradigms. We propose an innovative, pragmatic approach to CCC training through tailored subspecialty training in advanced heart failure and transplant cardiology (AHFTC), using elective time to enrich AHFTC training with skills and experiences necessary to become a highly skilled critical care cardiologist. The completion of this pathway would lead to completion of AHFTC training with a novel designation: distinction in critical care cardiology.

In Lamin A/C (Echocardiograms from patients with pathogenic or likely pathogenic variants inAt baseline, 43% of the patients with pathogenic or likely pathogenic

Lamin A/C gene (Patients withTwelve patients were enrolled; median (minimum, maximum) 6-minute walk test distance at baseline was 314 (246, 412) m. At week 12, the mean (80% CI) increase from baseline in 6-minute walk test distance was 69 (39, 100) m (median, 47 m). Median NT-proBNP concentration declined from 1409 pg/mL at baseline to 848 pg/mL at week 12. Mean left ventricular ejection fraction was stable at week 12. There was a trend toward improvement in Kansas City Cardiomyopathy Questionnaire Overall and Clinical Summary scores at week 12. No clinically significant drug-related safety concerns were identified.ARRY-371797 was well tolerated and resulted in increases in functional capacity and lower concentrations of cardiac biomarker NT-proBNP in patients withURL: https://clinicaltrials.gov; Unique identifier: NCT02057341.

Aims Risk stratification algorithms for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) and regional differences in clinical practice have evolved over time. We sought to compare primary prevention implantable cardioverter defibrillator (ICD) implantation rates and associated clinical outcomes in US vs. non-US tertiary HCM centres within the international Sarcomeric Human Cardiomyopathy Registry. Methods and results We included patients with HCM enrolled from eight US sites (n = 2650) and five non-US (n = 2660) sites and used multivariable Cox-proportional hazards models to compare outcomes between sites. Primary prevention ICD implantation rates in US sites were two-fold higher than non-US sites (hazard ratio (HR) 2.27 [1.89–2.74]), including in individuals deemed at high 5-year SCD risk (≥6%) based on the HCM risk-SCD score (HR 3.27 [1.76–6.05]). US ICD recipients also had fewer traditional SCD risk factors. Among ICD recipients, rates of appropriate ICD therapy were significantly lower in US vs. non-US sites (HR 0.52 [0.28–0.97]). No significant difference was identified in the incidence of SCD/resuscitated cardiac arrest among non-recipients of ICDs in US vs. non-US sites (HR 1.21 [0.74–1.97]). Conclusion Primary prevention ICDs are implanted more frequently in patients with HCM in US vs. non-US sites across the spectrum of SCD risk. There was a lower rate of appropriate ICD therapy in US sites, consistent with a lower-risk population, and no significant difference in SCD in US vs. non-US patients who did not receive an ICD. Further studies are needed to understand what drives malignant arrhythmias, optimize ICD allocation, and examine the impact of different ICD utilization strategies on long-term outcomes in HCM.

Purpose of Review We explore the sex-specific interaction of genetics and the environment on the clinical course and outcomes of hypertrophic cardiomyopathy (HCM). Recent Findings Women account for approximately one-third of patients in specialist HCM centres and reported in observational studies. As a result, evidence informing clinical guideline recommendations is based predominantly on risk factors and outcomes seen in men. However, disease progression appears to be different between the sexes. Women present at a more advanced stage of disease, are older at diagnosis, have higher symptom burden, carry greater risk for heart failure and are at greater risk of mortality compared to men. Women are more likely to be gene-positive, while men are more likely to be gene-negative. The risk of sudden cardiac death and access to specialised care do not differ between the sexes. Summary Reporting sex-disaggregated results is essential to identify the mechanisms leading to sex differences in HCM.

Left ventricular outflow tract (LVOT) obstruction is a major determinant of heart failure symptoms in obstructive hypertrophic cardiomyopathy (oHCM). Aficamten, a next-in-class cardiac myosin inhibitor, may lower gradients and improve symptoms in these patients.This study aims to evaluate the safety and efficacy of aficamten in patients with oHCM.Patients with oHCM and LVOT gradients ≥30 mm Hg at rest or ≥50 mm Hg with Valsalva were randomized 2:1 to receive aficamten (n = 28) or placebo (n = 13) in 2 dose-finding cohorts. Doses were titrated based on gradients and ejection fraction (EF). Safety and changes in gradient, EF, New York Heart Association functional class, and cardiac biomarkers were assessed over a 10-week treatment period and after a 2-week washout.From baseline to 10 weeks, aficamten reduced gradients at rest (mean difference: -40 ± 27 mm Hg, and -43 ± 37 mm Hg in Cohorts 1 and 2, P = 0.0003 and P = 0.0004 vs placebo, respectively) and with Valsalva (-36 ± 27 mm Hg and -53 ± 44 mm Hg, P = 0.001 and 0.0001 vs placebo, respectively). There were modest reductions in EF (-6% ± 7.5% and -12% ± 5.9%, P = 0.007 and P0.0001 vs placebo, respectively). Symptomatic improvement in ≥1 New York Heart Association functional class was observed in 31% on placebo, and 43% and 64% on aficamten in Cohorts 1 and 2, respectively (nonsignificant). With aficamten, N-terminal pro-B-type natriuretic peptide was reduced (62% relative to placebo, P = 0.0002). There were no treatment interruptions and adverse events were similar between treatment arms.Aficamten resulted in substantial reductions in LVOT gradients with most patients experiencing improvement in biomarkers and symptoms. These results highlight the potential of sarcomere-targeted therapy for treatment of oHCM.

IMPORTANCE: Dilated cardiomyopathy (DCM) is frequently caused by genetic factors. Studies identifying deleterious rare variants have predominantly focused on early-onset cases, and little is known about the genetic underpinnings of the growing numbers of patients with DCM who are diagnosed when they are older than 60 years (ie, late-onset DCM). OBJECTIVE: To investigate the prevalence, type, and prognostic impact of disease-associated rare variants in patients with late-onset DCM. DESIGN, SETTING, AND PARTICIPANTS: A population of patients with late-onset DCM who had undergone genetic testing in 7 international tertiary referral centers worldwide were enrolled from March 1990 to August 2020. A positive genotype was defined as the presence of pathogenic or likely pathogenic (P/LP) variants. MAIN OUTCOMES AND MEASURES: The study outcome was all-cause mortality. RESULTS: A total of 184 patients older than 60 years (103 female [56%]; mean [SD] age, 67 [6] years; mean [SD] left ventricular ejection fraction, 32% [10%]) were studied. Sixty-six patients (36%) were carriers of a P/LP variant. Titin-truncating variants were the most prevalent (present in 46 [25%] of the total population and accounting for 46 [69%] of all genotype-positive patients). During a median (interquartile range) follow-up of 42 (10-115) months, 23 patients (13%) died; 17 (25%) of these were carriers of P/LP variants, while 6 patients (5.1%) were genotype-negative. CONCLUSIONS AND RELEVANCE: Late-onset DCM might represent a distinct subgroup characterized by and a high genetic variation burden, largely due to titin-truncating variants. Patients with a positive genetic test had higher mortality than genotype-negative patients. These findings support the extended use of genetic testing also in older patients.

Background Patients with nonobstructive hypertrophic cardiomyopathy (nHCM) often experience a high burden of symptoms; however, there are no proven pharmacological therapies. By altering t...

Background: The term “end stage” has been used to describe hypertrophic cardiomyopathy (HCM) with left ventricular systolic dysfunction (LVSD), defined as occurring when left ventricular ejection fraction is Methods: Data from 11 high-volume HCM specialty centers making up the international SHaRe Registry (Sarcomeric Human Cardiomyopathy Registry) were used to describe the natural history of patients with HCM-LVSD. Cox proportional hazards models were used to identify predictors of prognosis and incident development. Results: From a cohort of 6793 patients with HCM, 553 (8%) met the criteria for HCM-LVSD. Overall, 75% of patients with HCM-LVSD experienced clinically relevant events, and 35% met the composite outcome (all-cause death [n=128], cardiac transplantation [n=55], or left ventricular assist device implantation [n=9]). After recognition of HCM-LVSD, the median time to composite outcome was 8.4 years. However, there was substantial individual variation in natural history. Significant predictors of the composite outcome included the presence of multiple pathogenic/likely pathogenic sarcomeric variants (hazard ratio [HR], 5.6 [95% CI, 2.3–13.5]), atrial fibrillation (HR, 2.6 [95% CI, 1.7–3.5]), and left ventricular ejection fraction Conclusions: HCM-LVSD affects ≈8% of patients with HCM. Although the natural history of HCM-LVSD was variable, 75% of patients experienced adverse events, including 35% experiencing a death equivalent an estimated median time of 8.4 years after developing systolic dysfunction. In addition to clinical features, genetic substrate appears to play a role in both prognosis (multiple sarcomeric variants) and the risk for incident development of HCM-LVSD (thin filament variants).

Introduction: Biallelic damaging variants in ALPK3, encoding alpha-protein kinase 3, cause pediatric-onset cardiomyopathy with manifestations that are incompletely defined. Methods and Results: We analyzed clinical manifestations of damaging biallelic ALPK3 variants in 19 pediatric patients, including nine previously published cases. Among these, 11 loss-of-function (LoF) variants, seven compound LoF and deleterious missense variants, and one homozygous deleterious missense variant were identified. Among 18 live-born patients, 8 exhibited neonatal dilated cardiomyopathy (44.4%; 95% CI: 21.5%-69.2%) that subsequently transitioned into ventricular hypertrophy. The majority of patients had extracardiac phenotypes, including contractures, scoliosis, cleft palate, and facial dysmorphisms. We observed no association between variant type or location, disease severity, and/or extracardiac manifestations. Myocardial histopathology showed focal cardiomyocyte hypertrophy, subendocardial fibroelastosis in patients under 4 years of age, and myofibrillar disarray in adults. Rare heterozygous ALPK3 variants were also assessed in adult-onset cardiomyopathy patients. Among 1548 Dutch patients referred for initial genetic analyses, we identified 39 individuals with rare heterozygous ALPK3 variants (2.5%; 95% CI: 1.8%-3.4%), including 26 missense and 10 LoF variants. Among 149 U.S. patients without pathogenic variants in 83 cardiomyopathy-related genes, we identified six missense and nine LoF ALPK3 variants (10.1%; 95% CI: 5.7%-16.1%). LoF ALPK3 variants were increased in comparison to matched controls (Dutch cohort, P = 1.6×10−5; U.S. cohort, P = 2.2×10−13). Conclusion: Biallelic damaging ALPK3 variants cause pediatric cardiomyopathy manifested by DCM transitioning to hypertrophy, often with poor contractile function. Additional extracardiac features occur in most patients, including musculoskeletal abnormalities and cleft palate. Heterozygous LoF ALPK3 variants are enriched in adults with cardiomyopathy and may contribute to their cardiomyopathy. Adults with ALPK3 LoF variants therefore warrant evaluations for cardiomyopathy.

Background: Pathogenic variants in MYBPC3 , encoding cardiac MyBP-C (myosin binding protein C), are the most common cause of familial hypertrophic cardiomyopathy. A large number of unique MYBPC3 variants and relatively small genotyped hypertrophic cardiomyopathy cohorts have precluded detailed genotype-phenotype correlations. Methods: Patients with hypertrophic cardiomyopathy and MYBPC3 variants were identified from the Sarcomeric Human Cardiomyopathy Registry. Variant types and locations were analyzed, morphological severity was assessed, and time-event analysis was performed (composite clinical outcome of sudden death, class III/IV heart failure, left ventricular assist device/transplant, atrial fibrillation). For selected missense variants falling in enriched domains, myofilament localization and degradation rates were measured in vitro. Results: Among 4756 genotyped patients with hypertrophic cardiomyopathy in Sarcomeric Human Cardiomyopathy Registry, 1316 patients were identified with adjudicated pathogenic truncating (N=234 unique variants, 1047 patients) or nontruncating (N=22 unique variants, 191 patients) variants in MYBPC3 . Truncating variants were evenly dispersed throughout the gene, and hypertrophy severity and outcomes were not associated with variant location (grouped by 5′–3′ quartiles or by founder variant subgroup). Nontruncating pathogenic variants clustered in the C3, C6, and C10 domains (18 of 22, 82%, P Conclusions: Truncating variants account for 91% of MYBPC3 pathogenic variants and cause similar clinical severity and outcomes regardless of location, consistent with locus-independent loss-of-function. Nontruncating MYBPC3 pathogenic variants are regionally clustered, and a subset also cause loss of function through failure of myofilament incorporation and rapid degradation. Cardiac morphology and clinical outcomes are similar in patients with truncating versus nontruncating variants.

Background In patients hospitalized with acute heart failure (AHF), low urine sodium concentration (U Na) after diuretic treatment may identify patients at risk for longer length of stay (LOS) and adverse events. We investigated the prognostic significance of 24‐hour cumulative postdiuretic urine sodium concentration in a multicenter clinical trial population. Methods The Renal Optimization Strategies Evaluation AHF (ROSE AHF) trial randomized 360 patients with AHF and renal dysfunction receiving intravenous diuretic to dopamine, nesiritide, or placebo. Sodium concentration was measured in cumulative urine sample collected during the first 24 hours after randomization in 298 patients. Based on prior studies, lower U Na was defined as ≤60 mmol/L. Results Lower U Na was present in 142 (48%) patients, who had longer LOS (7 days vs 5 days, P

Introduction: Genetic hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited condition primarily due to pathogenic variants in sarcomere genes, often with marked clinical variability. We hypothesized that this variability may, in part, be due to additive effects from low penetrance sarcomere variants that would otherwise be dismissed due to high population prevalence. Methods: Low-penetrance HCM-associated sarcomere gene variants were identified by meeting a threshold for enrichment in HCM (ascertained from the Sarcomeric Human Cardiomyopathy Registry, SHaRe) versus the general population (ascertained from the Genome Aggregation Database, gnomAD), defined by an odds ratio (OR) >5, and a population prevalence greater than the most common autosomal dominant pathogenic HCM variant, MYBPC3 R502W (4x10 -5 ). Clinical variables and time-event analyses were performed from SHaRe . Results: A total of 507 unique sarcomere gene variants were present in 6384 individuals with genetic testing. Ten putative low-penetrance variants were identified in the genes MYBPC3 (N=2), TNNT2 (N=1), TNNI3 (N=2), and MYH7 (N=5) with a combined OR of 12.7 (range 5.8 - 28.4). These variants had a population prevalence of 4.02x10 -5 to 3.5x10 -4 . Family members of low-penetrance variant carriers were less likely to have HCM (35/171, 20%) than those of MYBPC3 R502W carriers (44/113, 39%, p Conclusions: A subset of low-penetrance sarcomere gene variants are tolerated in the general population at higher than expected proportions for HCM and may exert an additive pathogenic effect. These findings support an oligogenic risk model of HCM.

Introduction: Dilated cardiomyopathy due to LMNA gene mutations ( LMNA -DCM) accounts for ~6% of DCM cases and is a life-threatening condition with a high unmet need. No disease-specific treatment targeting the underlying mechanism of disease is currently available. ARRY-371797 (PF-0765803), a potent, selective, oral, small-molecule inhibitor of the p38α MAPK pathway, improved exercise capacity (6MWT) in symptomatic LMNA -DCM patients (n=12) in a 48-week, open-label, Phase 2 study. Methods: This was an open-label rollover study of the long-term safety and efficacy of ARRY-371797 in symptomatic LMNA -DCM patients previously participating in the Phase 2 parent study, with eligible patients continuing on the same dose. Safety and efficacy assessments (6MWT, NT-proBNP, and KCCQ) were performed at Weeks 48, 72, 96, 120, and 144 from treatment initiation in the parent study. Results: Eight patients were enrolled (mean [SD] age, 51 [10] years; 4 males). There was a >30 m mean improvement and >10% mean increase in 6MWT distance from parent study baseline up to Week 120 ( Table ), with 3 patients (37.5%) having ≥10% improvement from baseline to Week 144. The decrease in mean NT-proBNP concentration in the parent study was maintained ( Table ). KCCQ Physical Limitation score increased at all visits except Week 48. Changes in KCCQ Clinical Summary and Overall Summary scores were variable. Treatment was generally well tolerated: 3 patients discontinued due to causes not considered treatment-related (UTI and nausea, CRT-D, and LVAD implantation); 2 experienced Grade 1 adverse events considered treatment-related. There were no deaths. Conclusions: ARRY-371797 was generally well tolerated, with evidence suggesting preserved exercise capacity over >2 years’ follow-up. Efficacy and safety of ARRY-371797 is being investigated in the REALM-DCM trial, an ongoing, pivotal, Phase 3, randomized, placebo-controlled study in LMNA -DCM.

Background:HeterozygousTTNtruncating variants cause 10% to 20% of idiopathic dilated cardiomyopathy (DCM). Although variants which disrupt canonical splice signals (ie, invariant dinucleotide of the splice donor site, invariant dinucleotide of the splice acceptor site) at exon-intron junctions are readily recognized asTTNtruncating variants, the effects of other nearby sequence variations on splicing and their contribution to disease is uncertain.Methods:Rare variants of unknown significance located in the splice regions of highly expressedTTNexons from 203 DCM cases, 3329 normal subjects, and clinical variant databases were identified. The effects of these variants on splicing were assessed using an in vitro splice assay.Results:Splice-altering variants of unknown significance were enriched in DCM cases over controls and present in 2% of DCM patients (P=0.002). Application of this method to clinical variant databases demonstrated 20% of similar variants of unknown significance inTTNsplice regions affect splicing. Noncanonical splice-altering variants were most frequently located at position +5 of the donor site (P=4.4×107) and position -3 of the acceptor site (P=0.002). SpliceAI, an emerging in silico prediction tool, had a high positive predictive value (86%–95%) but poor sensitivity (15%–50%) for the detection of splice-altering variants. Alternate exons spliced out of mostTTNtranscripts frequently lacked the consensus base at +5 donor and −3 acceptor positions.Conclusions:Noncanonical splice-altering variants inTTNexplain 1-2% of DCM and offer a 10-20% increase in the diagnostic power ofTTNsequencing in this disease. These data suggest rules that may improve efforts to detect splice-altering variants in other genes and may explain the low percent splicing observed for many alternateTTNexons.

BACKGROUND: Heterozygous truncating variants in titin (TTNtv) cause 10–20% of idiopathic dilated cardiomyopathy (DCM). Though variants which disrupt canonical splice signals (i.e. GT, AG) at exon-intron junctions are readily recognized as TTNtv, the effects of other nearby sequence variations on splicing and their contribution to disease is uncertain. METHODS: Rare variants of unknown significance (VUS) located in the splice regions of highly expressed TTN exons from 203 DCM cases, 3329 normal subjects, and clinical variant databases were identified. The effects of these variants on splicing were assessed using an in vitro splice assay. RESULTS: Splice-altering VUS were enriched in DCM cases over controls and present in 2% of DCM patients (p=0.002). Application of this method to clinical variant databases demonstrated 20% of similar VUS in TTN splice regions affect splicing. Non-canonical splice-altering variants were most frequently located at position +5 of the donor site (p=4.4e-7) and position −3 of the acceptor site (p=0.002). SpliceAI, an emerging in-silico prediction tool, had a high positive predictive value (86–95%) but poor sensitivity (15–50%) for the detection of splice-altering variants. Alternate exons spliced out of most TTN transcripts frequently lacked the consensus base at +5 donor and −3 acceptor positions. CONCLUSION: Non-canonical splice-altering variants in TTN explain 1–2% of DCM and offer a 10–20% increase in the diagnostic power of TTN sequencing in this disease. These data suggest rules that may improve efforts to detect splice-altering variants in other genes and may explain the low percent splicing observed for many alternate TTN exons.

Sarcoidosis is a complex, multisystem inflammatory disease with a heterogeneous clinical spectrum. Approximately 25% of patients with systemic sarcoidosis will have cardiac involvement that portends a poorer outcome. The diagnosis, particularly of isolated cardiac sarcoidosis, can be challenging. A paucity of randomised data exist on who, when and how to treat myocardial inflammation in cardiac sarcoidosis. Despite this, corticosteroids continue to be the mainstay of therapy for the inflammatory phase, with an evolving role for steroid-sparing and biological agents. This review explores the immunopathogenesis of inflammation in sarcoidosis, current evidence-based treatment indications and commonly used immunosuppression agents. It explores a multidisciplinary treatment and monitoring approach to myocardial inflammation and outlines current gaps in our understanding of this condition, emerging research and future directions in this field.

Lamin Cardiomyopathy (LC) is associated with refractory ventricular arrhythmias. Catheter ablation success rate is low due to presence of multiple circuits and intramural substrate. We present a LC case presented with electrical storm. During catheter ablation, arrhythmia was easily inducible but activation mapping, including full epicardial and endocardial mapping, failed to demonstrate the full tachycardia cycle length (70% only) suggesting intramural activation. Critical isthmus was not identified even with successful concealed entrainment on both Endo/epicardial surfaces. This case shows that even combined endocardial and epicardial catheter approach can be ineffective in identifying the full arrhythmogenic substrate in LC.

There is increasing understanding of the genetic basis to dilated cardiomyopathy and in this review, we offer a practical primer for the practising clinician. We aim to help all clinicians involved in the care of patients with dilated cardiomyopathy to understand the clinical relevance of the genetic basis of dilated cardiomyopathy, introduce key genetic concepts, explain which patients and families may benefit from genetic testing, which genetic tests are commonly performed, how to interpret genetic results, and the clinical applications of results. We conclude by reviewing areas for future research in this dynamic field.

Background Patient limitations guide selection of heart failure therapies, for which indications often specify New York Heart Association Class. Objectives To determine the extent of patient‐reported limitations during daily activities and compare to New York Heart Association class assigned by providers during the same visit, and to left ventricular ejection fraction (LVEF) group. Methods and Results While waiting for their appointment, 948 patients on return visits to an ambulatory HF clinic completed a written questionnaire assessing specific activity limitations, which were compared to physician‐assigned NYHA class during the same visit. Patient‐reported limitation to perform daily activity ranged from 25% for bathing to 61% for yardwork or housework and 71% for jogging or hurrying. Most patients who did not report limitations to perform daily life activities were correctly classified as NYHA I by the physicians (76%), but 12% of the 376 patients classified as NYHA I reported limitations to showering or bathing and 73% reported limitations while doing yardwork or house work. Limitation to walking was reported by 172 patients (50%) classified as class II. Limitations to walking one block were most common in patients with LVEF ≥40% compared to patients with LVEF

Background: An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter-defibrillator implantation. Methods: We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development sample, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation sample. LTVTA was defined as (1) sudden cardiac death or (2) implantable cardioverter defibrillator–treated or hemodynamically unstable VTA. The prognostic model was derived using the Fine-Gray regression model. The net reclassification was compared with current clinical practice guidelines. The results are presented as means (SD) or medians [interquartile range]. Results: We included 444 patients, 40.6 (14.1) years of age, in the derivation sample and 145 patients, 38.2 (15.0) years, in the validation sample, of whom 86 (19.3%) and 34 (23.4%) experienced LTVTA over 3.6 [1.0–7.2] and 5.1 [2.0–9.3] years of follow-up, respectively. Predictors of LTVTA in the derivation sample were: male sex, nonmissense LMNA mutation, first degree and higher atrioventricular block, nonsustained ventricular tachycardia, and left ventricular ejection fraction (https://lmna-risk-vta.fr). In the derivation sample, C-index (95% CI) of the model was 0.776 (0.711–0.842), and the calibration slope 0.827. In the external validation sample, the C-index was 0.800 (0.642–0.959), and the calibration slope was 1.082 (95% CI, 0.643–1.522). A 5-year estimated risk threshold ≥7% predicted 96.2% of LTVTA and net reclassified 28.8% of patients with LTVTA in comparison with the guidelines-based approach. Conclusions: In comparison with the current standard of care, this risk prediction model for LTVTA in laminopathies significantly facilitated the choice of candidates for implantable cardioverter defibrillators. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03058185.

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is a variably penetrant disease increasingly identified in young patients. OBJECTIVES: This study sought to describe the diverse phenotype, genotype, and outcomes in pediatric and adolescent patients. METHODS: Records from 1999 to 2016 were reviewed for individuals age

BACKGROUND: Gallium-68 Dotatate binds preferentially to somatostatin receptor (sstr) subtype-2 (sstr-2) on inflammatory cells. We aimed at investigating the potential clinical use of sstr-targeted imaging for the detection of myocardial inflammation. METHODS: 13 patients with suspected cardiac sarcoidosis (CS) based on clinical history and myocardial uptake on recent fluorine-18 fluorodeoxyglucose (FDG) PET, were enrolled to undergo Dotatate PET after FDG PET (median time 37 days [IQR 25 – 55]). Additionally, we investigated ex-vivo the immunohistochemistry expression of sstr-2 in 3 explanted sarcoid hearts. RESULTS: All FDG scans showed cardiac uptake (focal/multifocal = 6, focal on diffuse/heterogeneous = 7), and 46% (n=6) extra-cardiac uptake (mediastinal/hilar). In comparison, Dotatate scans showed definite abnormal cardiac uptake (focal/multifocal) in 4 patients, probably abnormal (heterogenous/patchy) in 3, and negative uptake in 6 cases. Similarly, 6 patients had increased mediastinal/hilar Dotatate uptake. Overall concordance of FDG and Dotatate uptake was 54% in the heart and 100% for thoracic nodal activity. Quantitatively, FDG maximum standardized uptake value was 5.0 times [3.8 – 7.1] higher in the heart, but only 2.25 times [1.7 – 3.0; P=0.019] higher in thoracic nodes relative to Dotatate. Ex-vivo, sstr-2 immunostaining was weakly seen within well-formed granulomas in all 3 examined sarcoid heart specimens with no significant staining of background myocardium or normal myocardium. CONCLUSION: Our preliminary data suggests that, compared to FDG imaging, somatostatin receptor-targeted imaging may be less sensitive for the detection of myocardial inflammation, but comparable for detecting extra-cardiac inflammation.

Hypertrophic cardiomyopathy (HCM) is a disease of heart muscle, which affects ∼1 in 500 individuals and is characterized by increased left ventricular wall thickness. While HCM is caused by pathogenic variants in any one of eight sarcomere protein genes, clinical expression varies considerably, even among patients with the same pathogenic variant. To determine whether background genetic variation or environmental factors drive these differences, we studied disease progression in 11 pairs of monozygotic HCM twins. The twin pairs were followed for 5 to 14 y, and left ventricular wall thickness, left atrial diameter, and left ventricular ejection fraction were collected from echocardiograms at various time points. All nine twin pairs with sarcomere protein gene variants and two with unknown disease etiologies had discordant morphologic features of the heart, demonstrating the influence of nonhereditable factors on clinical expression of HCM. Whole genome sequencing analysis of the six monozygotic twins with discordant HCM phenotypes did not reveal notable somatic genetic variants that might explain their clinical differences. Discordant cardiac morphology of identical twins highlights a significant role for epigenetics and environment in HCM disease progression.

Background: The impact of sex on phenotypic expression in hypertrophic cardiomyopathy (HCM) has not been well characterized in genotyped cohorts. Methods: Retrospective cohort study from an international registry of patients receiving care at experienced HCM centers. Sex-based differences in baseline characteristics and clinical outcomes were assessed. Results: Of 5873 patients (3788 genotyped), 2226 (37.9%) were women. At baseline, women were older (49.0±19.9 versus 42.9±18.4 years, P P P MYH7 variants where age at diagnosis was comparable for women and men (n=492; 34.8±19.2 versus 33.3±16.8 years, P =0.39). Over 7.7 median years of follow-up, New York Heart Association III-IV heart failure was more common in women (hazard ratio, 1.87 [CI, 1.48–2.36], P P Conclusions: In HCM, women are older at diagnosis, partly modified by genetic substrate. Regardless of genotype, women were at higher risk of mortality and developing severe heart failure symptoms. This points to a sex-effect on long-term myocardial performance in HCM, which should be investigated further.

Background: Filamin C truncating variants ( FLNCtv ) cause a form of arrhythmogenic cardiomyopathy: the mode of presentation, natural history, and risk stratification of FLNCtv remain incompletely explored. We aimed to develop a risk profile for refractory heart failure and life-threatening arrhythmias in a multicenter cohort of FLNCtv carriers. Methods: FLNCtv carriers were identified from 10 tertiary care centers for genetic cardiomyopathies. Clinical and outcome data were compiled. Composite outcomes were all-cause mortality/heart transplantation/left ventricle assist device (D/HT/LVAD), nonarrhythmic death/HT/LVAD, and sudden cardiac death/major ventricular arrhythmias. Previously established cohorts of 46 patients with LMNA and 60 with DSP -related arrhythmogenic cardiomyopathies were used for prognostic comparison. Results: Eighty-five patients carrying FLNCtv were included (42±15 years, 53% men, 45% probands). Phenotypes were heterogeneous at presentation: 49% dilated cardiomyopathy, 25% arrhythmogenic left dominant cardiomyopathy, 3% arrhythmogenic right ventricular cardiomyopathy. Left ventricular ejection fraction was FLNCtv carriers did not significantly differ from LMNA carriers and DSP carriers. In FLNCtv carriers, left ventricular ejection fraction was associated with the risk of D/HT/LVAD and nonarrhythmic death/HT/LVAD. Conclusions: Among patients referred to tertiary referral centers, FLNCtv arrhythmogenic cardiomyopathy is phenotypically heterogeneous and characterized by a high risk of life-threatening arrhythmias, which does not seem to be associated with the severity of left ventricular dysfunction.