BACKGROUND: Cardiac involvement is the main determinant of adverse outcomes in Fabry disease. The study aimed to investigate cardiovascular outcomes in patients with Fabry disease. METHODS: This was a multicenter, retrospective, longitudinal study of consecutively referred adult patients with Fabry disease. The primary end point was the occurrence of major adverse cardiovascular events defined as a composite of cardiovascular death, major arrhythmic events, bradyarrhythmias requiring pacemaker implantation, and stroke. RESULTS: A total of 680 patients (age, 42.3±15.9 years; 41.0% male; 68.7% on disease-specific therapy) were included. During a median follow-up of 7.1 (interquartile range, 3.9–11.6) years, 92 patients (13.5%) experienced a major adverse cardiovascular event. At 10 years, freedom from major adverse cardiovascular event was 85.1% (95% CI, 81.3–88.2) and was lower in men compared with women (76.1% [95% CI, 68.9–81.9] versus 91.3% [95% CI, 87.0–94.2]; log-rank χ ² =26.9; P <0.001). On multivariable analysis, age (hazard ratio, 1.04 [95% CI, 1.01–1.06] per 1 year; P <0.001), estimated glomerular filtration rate (hazard ratio, 0.99 [95% CI, 0.98–0.99] per 1 mL/min per 1.73 m ² ; P <0.001), QRS interval (hazard ratio, 1.02 [95% CI, 1.01–1.03] per 1 ms; P =0.002), and left ventricular mass index (hazard ratio, 1.01 [95% CI, 1.00–1.01] per 1 g/m ² ; P =0.032) were independent predictors of major adverse cardiovascular events during follow-up. CONCLUSIONS: This study shows that the prevention and treatment of cardiovascular disease remain an unmet need for patients with Fabry disease.

PRKAG2 cardiomyopathy is a rare genetic disorder that manifests early in life with an autosomal dominant inheritance pattern. It harbors left ventricular hypertrophy (LVH), ventricular pre-excitation and progressively worsening conduction system defects. Its estimated prevalence among patients with LVH ranges from 0.23 to about 1%, but it is likely an underdiagnosed condition. We report the association of the PRKAG2 missense variant c.1006G>A p. (Val336Ile) with LVH, conduction abnormalities (short PR interval and incomplete right bundle branch bock) and early-onset arterial hypertension (AH) in a 44-year-old Caucasian patient. While cardiac magnetic resonance (CMR) showed a mild hypertrophic phenotype with maximal wall thickness of 17 mm in absence of tissue alterations, the electric phenotype was relevant including brady–tachy syndrome and recurrent syncope. The same variant has been detected in the patient’s sister and daughter, with LVH + early-onset AH and electrocardiographic (ECG) alterations + lipothymic episodes, respectively. Paying close attention to the coexistence of LVH and ECG alterations in the proband has been helpful in directing genetic tests to exclude primary cardiomyopathy. Hence, identifying the genetic basis in the patient allowed for familial screening as well as a proper follow-up and therapeutic management of the affected members. A review of the PRKAG2 cardiomyopathy literature is provided alongside the case report.

BACKGROUND: Implanted cardioverter-defibrillators (ICDs) have been used in patients with hypertrophic cardiomyopathy (HCM) to prevent sudden death, and have proven lifesaving for many patients. However, experience with ICD therapy has largely been derived from relatively small HCM cohorts confined to specific countries or regions of the world. Therefore, we sought to determine the effectiveness of ICDs in preventing sudden death due to life-threatening ventricular arrhythmias in a large international multicenter HCM population. METHODS: Databases from 25 HCM centers (8 in the United States, 9 in Europe, 4 in Asia, and 1 each in Australia, Africa, Mexico, and South America) were retrospectively interrogated to identify consecutive patients with HCM with ICDs (1992 to 2024) followed for 7±6 years (up to 32 years) for clinical outcomes. RESULTS: A total of 3387 patients were identified (63% men). They had a mean left ventricular thickness of 22±7 mm. The participants had received ICDs at a mean age of 47±17 years. Over follow-up, 550 patients (16%) experienced ≥1 appropriate ICD therapy (2.6%/y), including 86 of the 247 implanted for secondary prevention (35% [6.4%/y]) and 464 of the 3140 implanted for primary prevention (15% [2.2%/y]). Appropriate therapy occurred in the 464 primary prevention patients at a mean age of 49±17 years, with a median time to first appropriate therapy of 4 years after ICD implantation; 16% of these received their first appropriate therapy ≥10 years after implantation, and 47% experienced multiple interventions. Independent predictors of appropriate ICD therapy included unexplained syncope, left ventricular apical aneurysms, left ventricular systolic dysfunction, and nonsustained ventricular tachycardia on ambulatory monitoring. Of the 3140 primary prevention patients, 2946 survived (94%) and 194 died (6%) (0.8%/y), including 68 due to HCM (0.3%/y), predominantly of end-stage heart failure (n=43) or stroke (n=9). In contrast, 11 patients (0.4%) died suddenly, with device failures occurring in 2.4% of those with life-threatening ventricular tachyarrhythmias. Survival free from HCM-related mortality at 10 and 20 years was 97% and 91%, respectively. CONCLUSIONS: In this international multicenter study, the largest to date, including >3300 consecutive patients with HCM and ICDs, device therapy terminated potentially lethal ventricular tachyarrhythmias in 1 of 6 patients, with low HCM-related mortality rates for patients with ICDs. These novel data demonstrate the effectiveness of the ICD initiative, which has probably favorably altered the natural history of many patients with HCM worldwide.

Cardiac magnetic resonance (CMR) imaging provides significant advantages in the non-invasive diagnosis of cardiac diseases. An emerging phenotype is increasingly being described in CMR reports, the LGE “ring-like” pattern, which resembles a circumferential/semi-circumferential LV scar. Different conditions exhibit this fibrosis distribution, the majority of them being genetically determined and mostly involving cardiomyopathy-causative genes (desmosomal but also other non-desmosomal related genes). Furthermore, inflammatory diseases, such as myocarditis or sarcoidosis, could be responsible for LV fibrosis, potentially exhibiting an RL distribution. Given the heterogeneity of such conditions, effective patient management requires a stepwise and multiparametric diagnostic work-up that integrates clinical, instrumental, and genetic data to identify the specific aetiology and guide personalised treatments.

Background: Founder mutations in MYBPC3 may contribute substantially to the genetic burden of hypertrophic cardiomyopathy (HCM) and provide important insights into genotype–phenotype correlations and population-specific disease mechanisms. In this study, we investigated two recurrent canonical splice-site variants, MYBPC3 c.1458-1G>A and c.3331-1G>A, identified in patients with HCM from the Emilia-Romagna region of Northern Italy. Methods: Ninety-one unrelated patients with HCM carrying either MYBPC3c.1458-1G>A or c.3331-1G>A were analyzed. Haplotype reconstruction was performed to assess a possible founder effect and estimate the approximate age of the shared ancestral allele. Functional characterization was carried out by RNA sequencing of myocardial tissue to evaluate the impact of the variants on splicing. Clinical and phenotypic data were compared with those of carriers of other truncating MYBPC3 variants or pathogenic variants in other sarcomeric genes. Results: Both variants, classified as pathogenic according to ACMG criteria, shared a conserved variant-specific core haplotype. Founder age was estimated at approximately 10.5 generations (~262 years), consistent with a regional founder effect. RNA sequencing demonstrated aberrant splicing for both variants, resulting in premature termination codons and presumably subsequent nonsense-mediated mRNA decay. Clinically, carriers showed delayed disease onset, with a mean onset in the fifth decade of life, and a comparatively milder phenotype, including a lower incidence of sudden cardiac death, than patients carrying other truncating MYBPC3 variants or pathogenic variants in other sarcomeric genes. Both variants exhibited partial penetrance (approximately 63–67%) and age-dependent variable expressivity. Conclusions:MYBPC3 c.1458-1G>A and c.3331-1G>A represent novel founder alleles associated with HCM in Northern Italy. Identification of these locally prevalent variants improves molecular diagnosis, family screening, and supports the development of variant-targeted therapeutic approaches.

(1) Background: Anti-drug antibodies (ADAs) may develop during enzyme replacement therapy (ERT) for Fabry disease and potentially affect biochemical response. Evidence have been derived mainly from males, while comparisons between agalsidase-alpha and agalsidase-beta remain limited by differences in ADA assays. The aim of the study is to evaluate ADA prevalence and titers in patients with Fabry disease treated with agalsidase-alpha or agalsidase-beta and to investigate associations with sex, GLA genotype, residual α-galactosidase A activity, and lyso-Gb3 levels. (2) Methods: This multicenter observational study included 117 patients with Fabry disease receiving ERT (50 males, 67 females), treated with agalsidase-alpha (n = 52) or agalsidase-beta (n = 65). ADAs were measured using an in-house enzyme-linked immunosorbent assay, and lyso-Gb3 by liquid chromatography–tandem mass spectrometry. GLA variants were centrally classified as predicted null-type or predicted non-null-type on the basis of the variant class, and α-galactosidase A activity at diagnosis was normalized to the lower limit of the assay reference interval. Multivariable regression analysis identified factors associated with ADA positivity and lyso-Gb3 levels. (3) Results: ADAs were detected in 55/117 patients. Positivity was more frequent in males than females, with no statistically significant difference between agalsidase-alpha and agalsidase-beta. Predicted null-type variants were associated with higher ADA positivity and titers, particularly in males. In multivariable models, male sex and predicted null-type variants independently predicted ADA positivity, whereas higher normalized α-galactosidase A activity was associated with lower odds. ADA positivity was not independently associated with lyso-Gb3. (4) Conclusions: ADA detection was primarily associated with male sex and predicted null-type GLA variants; no statistically significant association with the agalsidase administered was found. The high prevalence of binding ADAs in females warrants confirmation using orthogonal and functional assays.