BACKGROUND: Dilated cardiomyopathy (DCM) is a genetically heterogeneous disease, presenting diverse clinical phenotypes and outcomes based on the underlying gene affected. The influence of sex on the gene-specific long-term prognosis of patients with genetic DCM remains unclear. This study aims to determine the effect of sex on the long-term prognosis per underlying genogroup. METHODS: A retrospective cohort study was conducted using data from 4 international referral centers. Baseline and longitudinal clinical data of patients with DCM, with a median follow-up of 6.7 years (interquartile range, 3.5–11.9 years), were collected. The study included men and women with DCM who had undergone genetic testing. Patients were categorized into 7 genotype groups: cytoskeletal/Z-disk, desmosomal, nuclear envelope, motor sarcomeric, TTN , other genetic, and genotype negative. The main outcomes measured were left ventricular reverse remodeling, mortality, heart failure hospitalization, heart transplantation, and malignant ventricular arrhythmias. RESULTS: Among 1716 patients, 1130 (66%) were men and 510 (30%) had a (likely) pathogenic variant. Ventricular remodeling was gene-dependent in women, with TTN patients exhibiting the highest rate ( P =0.003) and desmosomal patients the lowest ( P =0.04) compared with the genotype-negative group. After a median follow-up of 6.7 years, 334 men (29%) and 140 women (24%) reached the primary end point. Men with a (likely) pathogenic variant had the poorest prognosis, showing a higher rate of major adverse events (adjusted hazard ratio, 1.48 [95% CI, 1.12–1.95]; P =0.02) and malignant ventricular arrhythmias (adjusted hazard ratio, 1.83 [95% CI, 1.16–2.88]; P =0.009) compared with genotype-negative women. Prognosis varied by gene in men (log-rank P <0.0001) but not in women (log-rank P =0.1). The cytoskeletal/Z-disk, desmosomal, and nuclear envelope groups had the worst prognosis in men. CONCLUSIONS: The genetic architecture and sex are critical predictors of left ventricular reverse remodeling and long-term prognosis in DCM. These factors should be integrated into individualized risk prediction models to enhance clinical outcomes in patients with DCM.

Background: Desmoplakin (DSP) cardiomyopathy, caused by variants in the gene DSP , is a unique subtype of cardiomyopathy distinct from typical dilated or arrhythmogenic right ventricular cardiomyopathies. Specific diagnostic and disease staging criteria have yet to be developed for DSP cardiomyopathy. Objective: Utilizing a large cohort of DSP cardiomyopathy patients and their genotype-positive family members, this study aims to develop diagnostic and disease staging criteria for DSP cardiomyopathy. Methods: Patients from the DSP -ERADOS Network with complete rhythm monitoring, electrocardiogram and cardiac magnetic resonance imaging were enrolled. Diagnostic criteria were assessed in initially-presenting patients (probands) and their genotype-positive family members. Early disease criteria (with preserved left ventricular ejection fraction, LVEF) were integrated into standard LVEF-based classifications. Diagnostic and staging criteria were assessed by time-event analyses (major ventricular arrhythmia and heart failure events). Results: A total of 605 patients with complete diagnostic testing were included (mean age 40 yr, 60% female, 40% probands). The most prevalent disease features in probands were premature ventricular contractions (PVCs) >500/24hr (66%), nonsustained ventricular tachycardia (NSVT, 29%), LV late gadolinium enhancement (LGE, 53%), and reduced LVEF (44%). The presence of any one of these features was 97% sensitive for diagnosis (along with a DSP pathogenic variant) and were therefore considered as diagnostic criteria. Using these criteria, 77% of genotype-positive family members were considered clinically affected. Isolated right ventricular (RV) involvement occurred in only 0.7%. The absence of diagnostic criteria identified a low-risk group (composite event rate 0.8%/year, p50%, HR 2.7, p=0.04; intermediate: LVEF 41-49%, HR 3.7, p=0.009; advanced: LVEF <40% HR 10.3, p<0.001). LGE was mostly subepicardial (87%). Circumferential (ring-like) LGE was more frequent in intermediate or advanced vs early disease (66% vs 48%, p<0.001). Conclusion: This study identifies genotype-specific diagnostic and disease staging criteria for DSP cardiomyopathy that improve identification of risk for both heart failure and sustained ventricular arrhythmias. This work highlights how gene-specific criteria may be used to refine diagnosis and staging for cardiomyopathy subtypes – a critical step as gene-targeted treatments move toward clinical trials.

Background: Atrial dilated cardiomyopathy (ADCM) related to homozygous Natriuretic Peptide Precursor A (NPPA) pathogenic variants is an exceptionally rare inherited atrial cardiomyopathy characterized by progressive atrial enlargement, supraventricular arrhythmias, and eventual atrial standstill. Case summary: We report the case of a 9-year-old girl identified through population genetic screening as a homozygous carrier of the NPPA c.449G>A (p.Arg150Gln) variant who subsequently developed symptomatic paroxysmal atrial fibrillation (AF) at the age of 18. Although baseline cardiac investigations were normal, her current evaluation shows biatrial enlargement with preserved ventricular function. She underwent radiofrequency pulmonary vein isolation; however, recurrent symptomatic AF persists, requiring ongoing antiarrhythmic therapy and long-term oral anticoagulation (CHA₂DS₂-VA: 0; HAS-BLED: 0). Notably, patients with NPPA-related ADCM have a markedly increased thromboembolic risk due to progressive atrial mechanical failure, and anticoagulation should therefore be considered irrespective of conventional clinical risk scores. Discussion and conclusions: This case highlights the importance of genetic testing in young patients with atrial fibrillation and no underlying structural heart disease. The early identification of NPPA-related atrial dilated cardiomyopathy may aid in risk stratification and guide rhythm and anticoagulation management. Expanding genetic screening in select individuals with isolated atrial fibrillation may facilitate earlier diagnosis in this exceptionally rare condition.

We report the first known case of PAMI syndrome associated with pulmonary arterial hypertension (PAH) with a positive response to cyclophosphamide and pulmonary vasodilators. The patient's history began at 7 months with severe pancytopenia and fever. As time progressed, migrating arthritis, hepatosplenomegaly, and a growth deficit manifested without a plausible explanation. At the age of 17, worsening dyspnea led to a diagnosis of severe pre‐capillary pulmonary hypertension and, after a multidisciplinary evaluation, a dual therapy with both vasoactive and immunosuppressive agents led to rapid clinical improvement. After a decade of stability, stopping sildenafil caused deterioration, reversed upon reintroduction. Thirty years after the onset of signs and symptoms, a genetic test identified the underlying condition known as PAMI syndrome. As PAMI syndrome involves intense systemic inflammation similar to PAH related to systemic lupus erythematosus (SLE), parameters and functional autonomy appropriately responded to early immunosuppressive and vasoactive therapy. PAMI syndrome, a rare autoinflammatory disease, is linked to precapillary pulmonary hypertension but the exact cause and optimal treatment approach are not fully understood, requiring further research for clarification and improved treatment options.