Aims
In patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), implantable cardioverter-defibrillator (ICD) shocks are sometimes ineffective and may even trigger fatal electrical storms. We assessed the efficacy and complications of ICDs placed in patients with CPVT who presented with a sentinel event of sudden cardiac arrest (SCA) while undiagnosed and therefore untreated.
Methods and results
We analysed 136 patients who presented with SCA and in whom CPVT was diagnosed subsequently, leading to the initiation of guideline-directed therapy, including β-blockers, flecainide, and/or left cardiac sympathetic denervation. An ICD was implanted in 79 patients (58.1%). The primary outcome of the study was sudden cardiac death (SCD). The secondary outcomes were composite outcomes of SCD, SCA, appropriate ICD shocks, and syncope. After a median follow-up of 4.8 years, SCD had occurred in three patients (3.8%) with an ICD and none of the patients without an ICD (P = 0.1). SCD, SCA, or appropriate ICD shocks occurred in 37 patients (46.8%) with an ICD and 9 patients (15.8%) without an ICD (P < 0.0001). Inappropriate ICD shocks occurred in 19 patients (24.7%) and other device-related complications in 22 patients (28.9%).
Conclusion
In previously undiagnosed patients with CPVT who presented with SCA, an ICD was not associated with improved survival. Instead, the ICD was associated with both a high rate of appropriate ICD shocks and inappropriate ICD shocks along with other device-related complications. Strict adherence to guideline-directed therapy without an ICD may provide adequate protection in these patients without all the potential disadvantages of an ICD.
We provide further evidence that relatively common variants in KCNE1 may result in a mild QT phenotype designated as "LQT5-Lite" to distinguish such potentially proarrhythmic common variants (ie, functional risk alleles) from rare pathogenic variants that truly confer monogenic disease susceptibility, albeit with incomplete penetrance.
Significant paravalvular leak (PVL) complicates between 6% and 15% of valve replacements and can result in heart failure and hemolysis. Paravalvular leak can be effectively treated with repeat surgery; however, these procedures are associated with significant operative morbidity. Percutaneous PVL closure is increasingly being utilized as the first line therapy for symptomatic patients, but efficacy may be limited by the lack of dedicated closure devices. Areas covered: This article will review the etiology and prevalence of PVL, discuss outcomes with surgical closure, describe the mounting data supporting percutaneous interventions, and highlight areas for future research emphasizing the need for new dedicated closure devices. Expert commentary: Percutaneous PVL closure can be safely accomplished in the majority of patients with PVL thereby avoiding the risks associated with repeat surgical intervention. However, percutaneous interventions are associated with higher rates of persistent leakage in part due to off-label use of devices intended for other applications. Efforts to develop devices specifically intended for PVL closure are needed to further improve outcomes for percutaneous PVL closure.
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