A new model for predicting adverse outcomes in arrhythmogenic right ventricular cardiomyopathy

INTRODUCTION

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disease leading to ventricular arrhythmias and heart failure. Determining optimal time for heart transplantation (HTx) is challenging; therefore, it is necessary to identify risk factors for disease progression.

OBJECTIVES

The study aimed to identify predictors of end‑stage heart failure and to evaluate the role of biomarkers in predicting adverse outcomes in ARVC.

PATIENTS AND METHODS

A total of 91 individuals with ARVC (59 men; mean [SD] age, 47 [16] years) were included. In all patients, information on medical history was collected, electrocardiography and echocardiography were performed, and serum levels of selected biomarkers (soluble form of the ST2 protein [sST2], galectin‑3 [Gal‑3], extracellular matrix metalloproteinases [MMP‑2 and MMP‑9], N‑terminal pro-B‑type natriuretic peptide [NT‑proBNP], and high‑sensitivity troponin T [hs‑TnT]) were measured. Thereafter, the participants were followed for the primary end point of death or HTx, as well as the secondary end point of major arrhythmic events (MAEs), defined as sudden cardiac death, ventricular fibrillation, sustained ventricular tachycardia, or appropriate implantable cardioverter‑defibrillator intervention.

RESULTS

During the median (interquartile range) follow‑up of 36.4 (29.8-41.2) months, 13 patients (14%) reached the primary end point of death or HTx, and 27 (30%) experienced MAEs. The patients who achieved the primary end point had higher levels of sST2, MMP‑2, NT‑proBNP, and hs‑TnT, but not of Gal-3 and MMP-9. Three factors turned out to be independent predictors of death or HTx: higher NT‑proBNP concentration (≥890.3 pg/ml), greater right ventricular end‑diastolic area (≥39 cm2), and a history of atrial tachycardia. None of the biomarkers predicted MAEs.

CONCLUSIONS

An NT‑proBNP concentration greater than or equal to 890.3 pg/ml, right ventricular end-diastolic area of 39 cm2 or greater, and a history of atrial tachycardia were identified as risk factors for death or HTx in ARVC. Higher levels of sST2, MMP‑2, NT‑proBNP, and hs‑TnT were associated with reaching the primary end point of death or HTx. The biomarkers had no value in predicting ventricular arrhythmias.

Pathogenic variants in plakophilin-2 gene (PKP2) are associated with better survival in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is mainly caused by mutations in genes encoding desmosomal proteins. Variants in plakophilin-2 gene (PKP2) are the most common cause of the disease, associated with conventional ARVC phenotype. The study aims to evaluate the prevalence of PKP2 variants and examine genotype-phenotype correlation in Polish ARVC cohort. All 56 ARVC patients fulfilling the current criteria were screened for genetic variants in PKP2 using denaturing high-performance liquid chromatography or next-generation sequencing. The clinical evaluation involved medical history, electrocardiogram, echocardiography, and follow-up. Ten variants (5 frameshift, 2 nonsense, 2 splicing, and 1 missense) in PKP2 were found in 28 (50%) cases. All truncating variants are classified as pathogenic/likely pathogenic, while the missense variant is classified as variant of uncertain significance. Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003), more often had negative T waves in V1-V3 (p = 0.01), had higher left ventricular ejection fraction (p = 0.04), and were less likely to present symptoms of heart failure (p = 0.01) and left ventricular damage progression (p = 0.04). Combined endpoint of death or heart transplant was more frequent in subgroup without PKP2 mutation (p = 0.03). Pathogenic variants in PKP2 are responsible for 50% of ARVC cases in the Polish population and are associated with a better prognosis. ARVC patients with PKP2 mutation are less likely to present left ventricular involvement and heart failure symptoms. Combined endpoint of death or heart transplant was less frequent in this group.

Implantable cardiac defibrillator events in patients with arrhythmogenic right ventricular cardiomyopathy

OBJECTIVE

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a risk of sudden cardiac death. Optimal risk stratification is still under debate. The main purpose of this long-term, single-centre observation was to analyse predictors of appropriate and inappropriate implantable cardioverter-defibrillator (ICD) interventions in the population of patients with ARVC with a high risk of life-threatening arrhythmias.

METHODS

The study comprised 65 adult patients (median age 40 years, 48 men) with a definite diagnosis of ARVC who received ICD over a time span of 20 years in primary (40%) or secondary (60%) prevention of sudden cardiac death. The study endpoints were first appropriate and inappropriate ICD interventions (shock or antitachycardia pacing) after device implantation.

RESULTS

During a median follow-up of 7.75 years after ICD implantation, nine patients died and six individuals underwent heart transplantation. Appropriate ICD interventions occurred in 43 patients (66.2%) and inappropriate ICD interventions in 18 patients (27.7%). Multivariable analysis using cause-specific hazard model identified three predictors of appropriate ICD interventions: right ventricle dysfunction (cause-specific HR 2.85, 95% CI 1.56 to 5.21, p<0.001), age <40 years at ICD implantation (cause-specific HR 2.37, 95% CI 1.13 to 4.94, p=0.022) and a history of sustained ventricular tachycardia (cause-specific HR 2.55, 95% CI 1.16 to 5.63, p=0.020). Predictors of inappropriate ICD therapy were not found. Complications related to ICD implantation occurred in 12 patients.

CONCLUSIONS

Right ventricle dysfunction, age <40 years and a history of sustained ventricular tachycardia were predictors of appropriate ICD interventions in patients with ARVC. The results may be used to improve risk stratification before ICD implantation.

Ablation of atrial tachyarrhythmias late after surgical correction of tetralogy of Fallot: long-term follow-up

BACKGROUND

After the surgical correction of tetralogy of Fallot, surgical scars and natural obstacles form pathways capable of supporting an atrial tachyarrhythmia (AT). Radiofrequency (RF) ablation is effective, although the few studies published on this topic had relatively short follow-up periods.

AIM

The aims of the study were to evaluate the acute and long-term effects of RF ablation of AT and examine the charac-teristics of arrhythmia recurrence.

METHODS

Tetralogy of Fallot patients (n = 16, age 44.7 ± 10.7 years) referred for ablation of ATs, appearing 25.7 ± 9.6 years after repair, were studied.

RESULTS

Twenty-five ATs were ablated, including 16 cavo-tricuspid isthmus atrial flutters (CTI-AFLs) and nine intraatrial reentrant tachycardia (IART). In one patient with paroxysmal atrial fibrillation (PAF), pulmonary vein isolation was also performed. Ten patients had permanent, and six had paroxysmal arrhythmia prior to the first ablation. Four patients had PAF. Regardless of the type of first ablated arrhythmia, all 16 patients required CTI-AFL ablation. The effectiveness of the first RF ablation reached 88%. The acute efficacy of RF ablation was 100% for CTI-AFL and 78% for IART. Long-term follow-up was possible in 15 out of 16 patients (mean follow-up 68.8 ± 36.6 months). Four patients were free of sustained arrhythmia, nine (60%) had AF. After the last RF ablation, an episode suggestive of CTI-AFL/IART was documented only in one patient.

CONCLUSIONS

Ablation of CTI-AFL/IART in tetralogy of Fallot patients is safe and effective. AF was observed in most patients during the long-term follow-up. Regardless of the type of the first ablated arrhythmia, all patients required CTI-AFL ablation.

Economic evaluation of screening for familiar form of arrhythmogenic right ventricular cardiomyopathy in Poland

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a myocardial disease associated with fibrofatty tissue replacement in heart muscle leading to arrhythmia, heart failure or sudden death (SCD) often being the first manifestation in probands. At least 50% of cases of ARVC are inherited.

AIM

To evaluate costs and cost-effectiveness of diagnosis of the disease in asymptomatic relatives in Poland.

METHODS

239 asymptomatic subjects (mean age 35 years, 120 male) belonging to 42 families affected with ARVC were examined between May 2003 and May 2005. The costs of outpatient visits and additional diagnostic tests were included. Payer perspective was used.

RESULTS

In all individuals ECG and transthoracic echocardiography were performed. Magnetic resonance imaging and signal-averaged ECG were performed in 35 patients suspected of having ARVC. The diagnostic criteria for ARVC were fulfilled in 29 patients and 57 subjects were recognised borderline. Total costs of screening amounted to 71 090 PLN (approximately 20,000 euro). The average cost per one case of detected ARVC was 2451 PLN (approximately 680 euro).

CONCLUSIONS

Costs of early detection of ARVC in individuals with a family history of the disease in Polish settings are low. Due the avilability of primary prevention of SCD the family screening in asymptomatic subjects is a cost-effective procedure.