Penetrance of Dilated Cardiomyopathy in Genotype-Positive Relatives

BACKGROUND

Disease penetrance in genotype-positive (G+) relatives of families with dilated cardiomyopathy (DCM) and the characteristics associated with DCM onset in these individuals are unknown.

OBJECTIVES

This study sought to determine the penetrance of new DCM diagnosis in G+ relatives and to identify factors associated with DCM development.

METHODS

The authors evaluated 779 G+ patients (age 35.8 ± 17.3 years; 459 [59%] females; 367 [47%] with variants in TTN) without DCM followed at 25 Spanish centers.

RESULTS

After a median follow-up of 37.1 months (Q1-Q3: 16.3-63.8 months), 85 individuals (10.9%) developed DCM (incidence rate of 2.9 per 100 person-years; 95% CI: 2.3-3.5 per 100 person-years). DCM penetrance and age at DCM onset was different according to underlying gene group (log-rank P = 0.015 and P <0.01, respectively). In a multivariable model excluding CMR parameters, independent predictors of DCM development were: older age (HR per 1-year increase: 1.02; 95% CI: 1.0-1.04), an abnormal electrocardiogram (HR: 2.13; 95% CI: 1.38-3.29); presence of variants in motor sarcomeric genes (HR: 1.92; 95% CI: 1.05-3.50); lower left ventricular ejection fraction (HR per 1% increase: 0.86; 95% CI: 0.82-0.90) and larger left ventricular end-diastolic diameter (HR per 1-mm increase: 1.10; 95% CI: 1.06-1.13). Multivariable analysis in individuals with cardiac magnetic resonance and late gadolinium enhancement assessment (n = 360, 45%) identified late gadolinium enhancement as an additional independent predictor of DCM development (HR: 2.52; 95% CI: 1.43-4.45).

CONCLUSIONS

Following a first negative screening, approximately 11% of G+ relatives developed DCM during a median follow-up of 3 years. Older age, an abnormal electrocardiogram, lower left ventricular ejection fraction, increased left ventricular end-diastolic diameter, motor sarcomeric genetic variants, and late gadolinium enhancement are associated with a higher risk of developing DCM.

Pregnancy in women with dilated cardiomyopathy genetic variants

INTRODUCTION AND OBJECTIVES

Limited information is available on the safety of pregnancy in patients with genetic dilated cardiomyopathy (DCM) and in carriers of DCM-causing genetic variants without the DCM phenotype. We assessed cardiac, obstetric, and fetal or neonatal outcomes in this group of patients.

METHODS

We studied 48 women carrying pathogenic or likely pathogenic DCM-associated variants (30 with DCM and 18 without DCM) who had 83 pregnancies. Adverse cardiac events were defined as heart failure (HF), sustained ventricular tachycardia, ventricular assist device implantation, heart transplant, and/or maternal cardiac death during pregnancy, or labor and delivery, and up to the sixth postpartum month.

RESULTS

A total of 15 patients, all with DCM (31% of the total cohort and 50% of women with DCM) experienced adverse cardiac events. Obstetric and fetal or neonatal complications were observed in 14% of pregnancies (10 in DCM patients and 2 in genetic carriers). We analyzed the 30 women who had been evaluated before their first pregnancy (12 with overt DCM and 18 without the phenotype). Five of the 12 (42%) women with DCM had adverse cardiac events despite showing NYHA class I or II before pregnancy. Most of these women had a history of cardiac events before pregnancy (80%). Among the 18 women without phenotype, 3 (17%) developed DCM toward the end of pregnancy.

CONCLUSIONS

Cardiac complications during pregnancy and postpartum were common in patients with genetic DCM and were primarily related to HF. Despite apparently good tolerance of pregnancy in unaffected genetic carriers, pregnancy may act as a trigger for DCM onset in a subset of these women.

Late gadolinium enhancement distribution patterns in non-ischaemic dilated cardiomyopathy: genotype-phenotype correlation

AIMS

Late gadolinium enhancement (LGE) is frequently found in patients with dilated cardiomyopathy (DCM); there is little information about its frequency and distribution pattern according to the underlying genetic substrate. We sought to describe LGE patterns according to genotypes and to analyse the risk of major ventricular arrhythmias (MVA) according to patterns.

METHODS AND RESULTS

Cardiac magnetic resonance findings and LGE distribution according to genetics were performed in a cohort of 600 DCM patients followed at 20 Spanish centres. After exclusion of individuals with multiple causative gene variants or with variants in infrequent DCM-causing genes, 577 patients (34% females, mean age 53.5 years, left ventricular ejection fraction 36.9 ± 13.9%) conformed to the final cohort. A causative genetic variant was identified in 219 (38%) patients, and 147 (25.5%) had LGE. Significant differences were found comparing LGE patterns between genes (P < 0.001). LGE was absent or rare in patients with variants in TNNT2, RBM20, and MYH7 (0, 5, and 20%, respectively). Patients with variants in DMD, DSP, and FLNC showed a predominance of LGE subepicardial patterns (50, 41, and 18%, respectively), whereas patients with variants in TTN, BAG3, LMNA, and MYBPC3 showed unspecific LGE patterns. The genetic yield differed according to LGE patterns. Patients with subepicardial, lineal midwall, transmural, and right ventricular insertion points or with combinations of LGE patterns showed an increased risk of MVA compared with patients without LGE.

CONCLUSION

LGE patterns in DCM have a specific distribution according to the affected gene. Certain LGE patterns are associated with an increased risk of MVA and with an increased yield of genetic testing.

Combination of late gadolinium enhancement and genotype improves prediction of prognosis in non-ischemic dilated cardiomyopathy

Aims

Genotype and left ventricular scar on cardiac magnetic resonance (CMR) are increasingly recognized as risk markers for adverse outcomes in non‐ischaemic dilated cardiomyopathy (DCM). We investigated the combined influence of genotype and late gadolinium enhancement (LGE) in assessing prognosis in a large cohort of patients with DCM.

Methods and results

Outcomes of 600 patients with DCM (53.3 ± 14.1 years, 66% male) who underwent clinical CMR and genetic testing were retrospectively analysed. The primary endpoints were end‐stage heart failure (ESHF) and malignant ventricular arrhythmias (MVA). During a median follow‐up of 2.7 years (interquartile range 1.3–4.9), 24 (4.00%) and 48 (8.00%) patients had ESHF and MVA, respectively. In total, 242 (40.3%) patients had pathogenic/likely pathogenic variants (positive genotype) and 151 (25.2%) had LGE. In survival analysis, positive LGE was associated with MVA and ESHF (both, p < 0.001) while positive genotype was associated with ESHF (p = 0.034) but not with MVA (p = 0.102). Classification of patients according to genotype (G+/G−) and LGE presence (L+/L−) revealed progressively increasing events across L−/G−, L−/G+, L+/G− and L+/G+ groups and resulted in optimized MVA and ESHF prediction (p < 0.001 and p = 0.001, respectively). Hazard ratios for MVA and ESHF in patients with either L+ or G+ compared with those with L−/G− were 4.71 (95% confidence interval: 2.11–10.50, p < 0.001) and 7.92 (95% confidence interval: 1.86–33.78, p < 0.001), respectively.

Conclusion

Classification of patients with DCM according to genotype and LGE improves MVA and ESHF prediction. Scar assessment with CMR and genotyping should be considered to select patients for primary prevention implantable cardioverter‐defibrillator placement.

Association of Genetic Variants With Outcomes in Patients With Nonischemic Dilated Cardiomyopathy

BACKGROUND

The clinical relevance of genetic variants in nonischemic dilated cardiomyopathy (DCM) is unsettled.

OBJECTIVES

The study sought to assess the prognostic impact of disease-causing genetic variants in DCM.

METHODS

Baseline and longitudinal clinical data from 1,005 genotyped DCM probands were retrospectively collected at 20 centers. A total of 372 (37%) patients had pathogenic or likely pathogenic variants (genotype positive) and 633 (63%) were genotype negative. The primary endpoint was a composite of major adverse cardiovascular events. Secondary endpoints were end-stage heart failure (ESHF), malignant ventricular arrhythmia (MVA), and left ventricular reverse remodeling (LVRR).

RESULTS

After a median follow-up of 4.04 years (interquartile range: 1.70-7.50 years), the primary endpoint had occurred in 118 (31.7%) patients in the genotype-positive group and in 125 (19.8%) patients in the genotype-negative group (hazard ratio [HR]: 1.51; 95% confidence interval [CI]: 1.17-1.94; P = 0.001). ESHF occurred in 60 (16.1%) genotype-positive patients and in 55 (8.7%) genotype-negative patients (HR: 1.67; 95% CI: 1.16-2.41; P = 0.006). MVA occurred in 73 (19.6%) genotype-positive patients and in 77 (12.2%) genotype-negative patients (HR: 1.50; 95% CI: 1.09-2.07; P = 0.013). LVRR occurred in 39.6% in the genotype-positive group and in 46.2% in the genotype-negative group (P = 0.047). Among individuals with baseline left ventricular ejection fraction ≤35%, genotype-positive patients exhibited more major adverse cardiovascular events, ESHF, and MVA than their genotype-negative peers (all P < 0.02). LVRR and clinical outcomes varied depending on the underlying affected gene.

CONCLUSIONS

In this study, DCM patients with pathogenic or likely pathogenic variants had worse prognosis than genotype-negative individuals. Clinical course differed depending on the underlying affected gene.

Mutations in TRIM63 cause an autosomal-recessive form of hypertrophic cardiomyopathy

OBJECTIVE

Up to 50% of patients with hypertrophic cardiomyopathy (HCM) show no disease-causing variants in genetic studies. TRIM63 has been suggested as a candidate gene for the development of cardiomyopathies, although evidence for a causative role in HCM is limited. We sought to investigate the relationship between rare variants in TRIM63 and the development of HCM.

METHODS

TRIM63 was sequenced by next generation sequencing in 4867 index cases with a clinical diagnosis of HCM and in 3628 probands with other cardiomyopathies. Additionally, 3136 index cases with familial cardiovascular diseases other than cardiomyopathy (mainly channelopathies and aortic diseases) were used as controls.

RESULTS

Sixteen index cases with rare homozygous or compound heterozygous variants in TRIM63 (15 HCM and one restrictive cardiomyopathy) were included. No homozygous or compound heterozygous were identified in the control population. Familial evaluation showed that only homozygous and compound heterozygous had signs of disease, whereas all heterozygous family members were healthy. The mean age at diagnosis was 35 years (range 15-69). Fifty per cent of patients had concentric left ventricular hypertrophy (LVH) and 45% were asymptomatic at the moment of the first examination. Significant degrees of late gadolinium enhancement were detected in 80% of affected individuals, and 20% of patients had left ventricular (LV) systolic dysfunction. Fifty per cent had non-sustained ventricular tachycardia. Twenty per cent of patients suffered an adverse cerebrovascular event (20%).

CONCLUSION

TRIM63 appears to be an uncommon cause of HCM inherited in an autosomal-recessive manner and associated with concentric LVH and a high rate of LV dysfunction.

Clinical Findings and Prognosis of Danon Disease. An Analysis of the Spanish Multicenter Danon Registry

INTRODUCTION AND OBJECTIVES

Danon disease (DD) is caused by mutations in the LAMP2 gene. It is considered a multisystemic disease characterized by hypertrophic cardiomyopathy with pre-excitation and extreme hypertrophy, intellectual disability, myopathy, childhood presentation, and worse prognosis in men. There are scarce data on the clinical characteristics and prognosis of DD.

METHODS

We analyzed the clinical records of patients with DD from 10 Spanish hospitals.

RESULTS

Twenty-seven patients were included (mean age, 31 ± 19 years; 78% women). Male patients showed a high prevalence of extracardiac manifestations: myopathy (80%), learning disorders (83%), and visual alterations (60%), which were uncommon findings in women (5%, 0%, and 27%, respectively). Although hypertrophic cardiomyopathy was the most common form of heart disease (61%), the mean maximum wall thickness was 15 ± 7 mm and dilated cardiomyopathy was present in 12 patients (10 women). Pre-excitation was found in only 11 patients (49%). Age at presentation was older than 20 years in 16 patients (65%). After a median follow-up of 4 years (interquartile range, 2-9), 4 men (67%) and 9 women (43%) died or required a transplant. Cardiac disease and adverse events occurred later in women (37 ± 9 vs 23 ± 16 and 36 ± 20 vs 20 ± 11 years, respectively).

CONCLUSIONS

The clinical characteristics of DD differ substantially from traditional descriptions: age at presentation of DD is older, the disease is not multisystemic in women, and pre-excitation is infrequent.