Genetic Characterization of Dilated Cardiomyopathy in Romanian Adult Patients

Dilated cardiomyopathy (DCM) represents a group of disorders affecting the structure and function of the heart muscle, leading to a high risk of heart failure and sudden cardiac death (SCD). DCM frequently involves an underlying genetic etiology. Genetic testing is valuable for risk stratification, treatment decisions, and family screening. Romanian population data on the genetic etiology of DCM are lacking. We aimed to investigate the genetic causes for DCM among Romanian adult patients at tertiary referral centers across the country. Clinical and genetic investigations were performed on adult patients presenting to tertiary hospitals in Romania. The genetic investigations used next-generation sequencing panels of disease-associated DCM genes. A total of 122 patients with DCM underwent genetic testing. The mean age at DCM diagnosis was 41.6 ± 12.4 years. The genetic investigations identified pathogenic or likely pathogenic variants in 50.8% of participants, while 25.4% had variants of unknown significance. Disease-causing variants in 15 genes were identified in people with DCM, with 31 previously unreported variants. Variants in TTN, LMNA, and DSP explained 75% of genetic causes for DCM. In total, 52.4% of patients had a family history of DCM/SCD. Left ventricular ejection fraction of <35% was observed in 41.9% of patients with disease-causing variants and 55% with negative or uncertain findings. Further genotype-phenotype correlations were explored in this study population. The substantial percentage (50.8%) of disease-causing variants identified in patients with DCM acknowledges the importance of genetic investigations. This study highlights the genetic landscape in genes associated with DCM in the Romanian population.

1175Structural progression increases the risk of ventricular arrhythmias in patients with arrhythmogenic cardiomyopathy

Background

Arrhythmogenic cardiomyopathy (AC) is an inheritable cardiomyopathy with incomplete penetrance, variable phenotype severity and poorly described disease progression. It is characterized by high risk of life-threatening ventricular arrhythmias and sudden cardiac death in young individuals. Risk stratification and selection of patients presenting without history of life-threatening arrhythmic events for cardioverter-defibrillator implantation in primary prevention remains challenging.

Purpose

We aimed to assess the impact of disease progression on arrhythmic outcomes in AC patients.

Methods

We included consecutive AC probands and mutation-positive family members with at least one complete follow-up evaluation. Echocardiographic and electrical parameters were defined according to the 2010 Revised Task Force criteria at inclusion and at last follow-up. Structural progression was defined as development of new echocardiographic diagnostic criteria. Electrical progression was defined as the development of new diagnostic depolarization, repolarization and/or premature ventricular complex count criteria during follow-up. Non-sustained ventricular tachycardia or ventricular tachycardia occurring during follow-up defined incident ventricular arrhythmic events.

Results

We included a total of 144 patients (48% female, 47% probands, 40±16 years old). At inclusion, 54 patients (37%) had a history of arrhythmic events, 30 patients (21%) had overt structural disease and 114 (79%) had no or minor structural disease. During 7.0 (IQR: 4.5 to 9.4) years of follow-up, 49 patients (43%) with no or minor structural disease at inclusion developed new structural criteria being defined as progressors. Among 80 participants with no or minor structural disease and no arrhythmic history at inclusion, a first arrhythmic event occurred in 14 (17%). The incidence of arrhythmic events was higher in progressors (11/27, 41%) than in non-progressors (3/53, 6%) (p<0.001) (Figure). Structural progression was associated with higher risk of first arrhythmic events during follow-up when adjusted for sex, age at inclusion and follow-up duration, independent of electrical progression (7.6, 95% CI [1.5, 37.2], P=0.01).

Incident arrhythmic events distribution

Conclusion

Almost half of patients without overt structural cardiac disease at genetic diagnosis develop new structural criteria during 7 years follow-up and 17% experienced their first ventricular arrhythmic event. Structural progression was independently associated with ventricular arrhythmic events during follow-up. These findings highlight the increased risk of arrhythmias when structural abnormalities are detected. Their finding may initiate the evaluation for primary prevention cardioverter-defibrillator implantation.

Thrombophilia genetic testing in Romanian young women with acute thrombotic events: role of Factor V Leiden, Prothrombin G20210A, MTHFR C677T and A1298C polymorphisms / Evaluarea genetică a trombofiliilor la femei tinere din România cu evenimente acute trombotice: rolul Factorului V Leiden, Protrombinei G20210A, polimorfismelor MTHFR C677T și A1298C

Objective: The present case-control study aimed at evaluating the contribution of thrombophilic polymorphisms to acute venous (VTE) as well as arterial thrombotic events (ATE) in a population of young women with few traditional thrombotic factors (CVRF).

Methods: We consecutively enrolled patients under 45 years of age, with less than 3 CVRF, evaluated for VTE or ATE, women and men as a comparator. The control group consisted of healthy young women. A thrombophilia panel and genetic testing for Factor V Leiden (FVL), G20210A Prothrombin and MTHFR polimorphisms were done.

Results: A total of 323 persons were enrolled: 71 women and 121 men with thromboembolic events, and 131 healthy female as controls. Hyperhomocysteinemia was more frequent in ATE (30.4%) than VTE female patients (6.25%), p<0.01. Genetic testing was available in 45 women and 84 men with acute thrombotic events and in all controls. Homozygous FVL was associated with VTE in young women (10.3% vs 0% controls, p<0.01). Prothrombin G20210A polymorphism had the lowest prevalence – 5.4% and only heterozygosity was found. MTHFR C677T heterozygosity showed no significant difference between women patients and controls (62.2 % vs 43.5% respectively, p=0.1). The homozygous status, less frequent (6.6%), was not associated with ATE or VTE. Homozygous MTHFR A1298C was associated with VTE in women (17.2% patients vs 4.5% controls, OR 4.34, p 0.02, CI 1.22-15.3).

Conclusion: In young women with few CVRF, mild hyperhomocysteinemia, homozygosity for FVL and for MTHFR A1298C polymorphisms increase the risk for VTE but not ATE. MTHFR polymorphisms are found with increased frequency in both healthy persons and patients therefore, their significance as an important thrombotic risk modifier remains unclear.