C65 POST–DISCHARGE ARRHYTHMIC RISK STRATIFICATION OF PATIENTS WITH ACUTE MYOCARDITIS AND LIFE–THREATENING VENTRICULAR TACHYARRHYTHMIAS

Aims

The outcomes of patients presenting with acute myocarditis and life–threatening ventricular arrhythmias (LT–VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population.

Methods and Results

We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT–VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter–defibrillator therapy or synchronized external cardioversion. Median follow–up was 23months [first to third quartile (Q1–Q3) 7–60]. Fifty–eight (37.2%) patients experienced MAEs after discharge, at a median of 8 months (Q1–Q3 2.5–24.0 months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38–6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39–8.53), and absence of positive short–tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40–4.79) at first CMR.

Conclusions

In this international multicentre study, patients discharged free from HTx or LVAD after an acute myocarditis complicated by LT–VA had a recurrence of MAEs during follow–up of 37.2%, after a median time of 8 months. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence.

Apical sparing strain pattern observed in danon disease: insights from a global registry

Background

Danon Disease (DD) is a rare X-linked autophagic disorder due to mutations in the Lysosomal Associated Membrane Protein 2 (LAMP-2) gene and causes severe cardiac manifestations. Measurement of longitudinal strain (LS) has been shown to provide diagnostic insights into different etiologies of hypertrophic cardiomyopathies compared to conventional echocardiographic parameters.

Purpose

The aim of this study was to describe the pattern of global and regional LS in DD.

Methods

A retrospective, international registry, using medical records provided by patients, was formed to describe the natural history of DD. Complete echocardiogram images were available for review and LS was analyzed globally and regionally (basal, mid, apex).

Results

A total of eighteen DD patients (male 72%, mean age 17.2±10 years) had sufficient quality echocardiographic images for both traditional and myocardial strain evaluation. Notable traditional echocardiographic parameters included a mean EF of 60±11%, LV mass index 200±159 g/m2, intraventricular septal diameter 17.7±10.3 mm, LV posterior wall diameter 16.1±7.7 mm, LA volume index 21.9±13 mL/m2. Global longitudinal strain was reduced with a mean of −12.1±4.9% with an observed regional strain gradient: apex (−16.6±6.6%), mid (−10.9±4.7%) and basal (−9.2±4.5%). Bull's eye plot patterns reflected an apical sparing pattern that was similar to that described in cardiac amyloidosis.

Conclusion

In this DD cohort, we describe for the first time a strain pattern characterized by reduction in global longitudinal strain with apical sparing, which was originally pathognomonic for cardiac amyloidosis. This strain pattern in conjunction with a paradoxically normal LA volume may discriminate patients with DD from other hypertrophic conditions.

Funding Acknowledgement

Type of funding source: None

Cardiomyopathy phenotyping and risk-stratification in danon disease

Background

Danon Disease (DD) is a rare, X-linked vacuolar myopathy due to mutations in Lysosomal Associated Membrane Protein 2 (LAMP-2). Though it is strongly associated with severe cardiomyopathy, heart failure and sudden death, there is no data on typical cardiac magnetic resonance (CMR) imaging characteristics in DD and their association with clinical severity and outcome.

Purpose

To phenotype and risk-stratify DD patients.

Methods

CMR scans of confirmed DD patients recruited in a global registry were prospectively analyzed for biventricular volumes, ejection fraction (EF), left ventricular (LV) strain, mass (LVM) and late gadolinium enhancement (LGE) in a core-lab blinded fashion. A major adverse cardiac event (MACE) was a composite of death, heart transplant and implantable cardioverter defibrillator (ICD) for secondary prevention.

Results

12 DD patients (5 males [42%], median age 13 yrs [interquartile range (IQR) 5]) were included. LV hypertrophy (LVH) was present in 10/12 (83%), associated with LV dilation in 2 females. LVH was typically asymmetric in females (5/7) and concentric in males (3/5); right ventricular (RV) hypertrophy frequent in females (4/7). LV strain was reduced (global circumferential strain [GCS] −12±4%) and LGE common (73%), often extensive and always sparing the basal-mid septum. LGE was strongly associated with heart failure (BNP r=0.9, p=0.0021). Patients with MACE (6 [50%], median follow-up 2.9 yrs) had elevated LVM (241±63 g, p=0.032), impaired LV strain (GCS: −9.8±3.9, p=0.02) and higher LGE mass (median 56 g [IQR 35], p=0.021) compared to those without events during follow-up (LVM 155±56 g, GCS −14.9±1.6, LGE mass 0 g [IQR 8]). CMR characteristics were predictors of MACE (LV strain: hazard ratio [HR] 1.4, p=0.021; LGE mass: HR 1.1, p=0.03).

Conclusions

LGE sparing the basal-mid septum was pathognomonic in DD. LVH with reduced LV strain was the most common DD phenotype but the spectrum included LV dilation and RV hypertrophy in females. CMR characteristics (LV strain and LGE) were associated with heart failure and predicted worse outcome (heart transplant and fatal arrhythmias). CMR phenotyping and risk-stratification of this severe and underrecognized cardiomyopathy may aid diagnosis and clinical management in DD patients who need selection for early heart transplant, ICD implantation and targeted gene therapy.

Danon Disease Phenotypes and Outcome

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Institute of Health and Rocket Pharmaceuticals

P902Danon disease: clinical features and outcomes

Background

Danon Disease (DD) is a rare X-linked autophagic vacuolar myopathy, characterized by high penetrance and severe cardiomyopathy; cognitive, skeletal muscle and vision impairment may occur as well. Due to its rarity, clinical presentation and outcomes are still uncertain.

Purpose

To describe clinical features and outcomes of DD in female and male patients

Methods

Individuals and families from United Kingdom, Australia, and United States were recruited through via advertisements on Facebook groups related to DD. Participants completed a survey about symptoms and medical history and provided their medical records to the research team.

Results

A total of 44 patients (54.5% female) with positive genetic testing for DD were included. De novo mutations occurred in one out of four patients. Cardiomyopathy occurred in 86.3% of patients (18/24 females, 20/20 males) at a mean age of 7.3 years for males and 19.4 years for females (p=0.001). Females presented with either hypertrophic cardiomyopathy (HCM, 66.7%) or dilated cardiomyopathy (DCM, 8.3%) whereas males presented with HCM 90% of the time. 34.2% of patients were diagnosed with Wolff-Parkinson-White syndrome.

Twelve patients (7 females, 5 males) underwent cardiac magnetic resonance (CMR) Out of the 9 cases, 8 (88.9%) exhibited extensive patchy late gadolinium-enhancement (LGE) in multiple segments of the left ventricle; 3 cases also had right ventricular LGE. Median cardiac mass index was 155 g/m2 (Q1-Q3: 70–237; v.n. 31–79 g/m2). Overall, 17 (38.6%) patients died or required or heart transplant (HTx). Median age at the time of death or HTx was 17 years and 42 years in males and females, respectively (p=0.025 by the log-rank test)

Cognitive impairment, mainly described as learning disabilities, was diagnosed in 90.0% of males (18/20) and 79.2% (19/24) of females; intelligence quotient (IQ) measurement was reported in 8 patients (3 females, 5 males) and 7 of them showed IQ below the average. Symptomatic skeletal myopathy was present in 28 (63.3%) of patients, with a higher prevalence in males (85% vs. 45.8%; p<0.01). Retinopathy was reported in 14 (31.2%) patients and occurred equally in both genders (p=0.34).

Conclusions

DD causes significant cardiac morbidity with the need for transplant at a young age; in 25% of cases DD is due to a de novo mutation. While in males DD is more frequently multisystemic with a more rapid clinical deterioration, in females the clinical presentation is variable. However, the presence of severe cases in females warrant the clinicians to screen for DD in both sexes with clinical manifestations or positive family history

Acknowledgement/Funding

Rocket Pharmaceuticals

2422Outcome of histologically-proven fulminant versus acute non-fulminant myocarditis with left ventricular systolic dysfunction. Evidence from the International Registry on Acute Myocarditis

Background

Fulminant myocarditis (FM) is a form of acute myocarditis characterized by severe left ventricular (LV) dysfunction requiring inotropes and/or mechanical circulatory support. Based on a retrospective single-center study published in 2000, patients with FM were considered to have better outcomes than those affected by acute non-fulminant myocarditis (NFM) presenting with LV systolic dysfunction (LVSD). Recently, this tenet was challenged, though substantial disagreement still exists.

Purpose

Aim of the present study is to provide additional evidence on the outcome of FM and to ascertain if patient stratification based on the main histologic subtypes can provide additional prognostic information.

Methods

Two hundred and twenty patients (median age 42 years, 46.3% female) with histologically proven acute myocarditis (onset of symptoms <30 days) presenting with LVSD were included in a retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan. The primary endpoint was the occurrence of cardiac death or heart transplant (HTx) within 60 days from admission and at long-term follow-up.

Results

Patients with FM (N=165) had significantly higher rates of cardiac death and HTx compared with those with NFM (N=55), both at 60 days (28.0% vs. 1.8%, p=0.0001) and at 7-year follow up (47.7% vs. 10.4%, p<0.0001; Figure). At Cox-multivariate analysis, the histologic subtype emerged as a further variable affecting outcome in FM patients, with giant cell myocarditis having a significantly worse prognosis compared with eosinophilic and lymphocytic myocarditis both at 60 days (62.5% vs. 26.3% vs. 21.0%) and at 3 years (81.3% vs. 39.9% vs. 37.3%, overall p<0.0001). In a sub-analysis including only adults with lymphocytic myocarditis, the main endpoints occurred more frequently in FM compared with NFM both at 60 days (19.5% vs. 0%, p=0.005) and up to 7 years (41.4% vs. 3.1%, p=0.0004).

Outcome of FM vs NFM

Conclusions

The results of this international registry confirm that patients with FM have higher rates of cardiac death and HTx both in the short and long-term compared with patients with NFM. Furthermore, we provide evidence that the histologic subtype of FM carries independent prognostic value, highlighting the need for timely endomyocardial biopsy in this condition.

Acknowledgement/Funding

None