Subcutaneous implantable cardioverter defibrillator indication in prevention of sudden cardiac death in difficult clinical situations: A French expert position paper

Molecular genetic screening after non-ischaemic sudden cardiac arrest and no overt cardiomyopathy in real life: A major tool for the aetiological diagnostic work-up

BACKGROUND

With the development of advanced sequencing techniques, genetic testing has emerged as a valuable tool for the work-up of non-ischaemic sudden cardiac arrest (SCA).

AIMS

To evaluate the effectiveness of genetic testing in patients with unexplained SCA, according to clinical phenotype.

METHODS

All patients who underwent molecular genetic testing for non-ischaemic SCA with no left ventricular cardiomyopathy between 2012 and 2021 in two French university hospitals were included.

RESULTS

Of 66 patients (mean age 36.7±11.9years, 54.5% men), 21 (31.8%; 95% confidence interval 22.4-45.3%) carried a genetic variant: eight (12.1%) had a pathogenic or likely pathogenic (P/LP) variant and 13 (19.7%) had a variant of uncertain significance (VUS). Among 37 patients (56.1%) with no phenotypic clues, genetic testing identified a P/LP variant in five (13.5%), mainly in RYR2 (n=3) and SCN5A (n=2), and a VUS in nine (24.3%). None of the nine patients with phenotypic evidence of channelopathies had P/LP variants, but two had VUS in RYR2 and NKX2.5. Among the 20 patients with suspected arrhythmogenic cardiomyopathy, three P/LP variants (15.0%) and two VUS (10.0%) were found in DSC2, PKP2, SCN5A and DSG2, TRPM4, respectively. Genetic testing was performed sooner after cardiac arrest (P<0.001) and results were obtained more rapidly (P=0.02) after versus before 2016.

CONCLUSION

This study highlights the utility of molecular genetic testing with a genetic variant of interest identified in one-third of patients with unexplained SCA. Genetic testing was beneficial even in patients without phenotypic clues, with one-fourth of patients carrying a P/LP variant that could have direct implications.

Inappropriate shock incidence in patients with subcutaneous implantable cardioverter-defibrillators with concomitant cardiac implantable electronic devices: A single-center cohort study

BACKGROUND

Subcutaneous implantable cardioverter defibrillators (S-ICDs) are occasionally used in combination with other cardiac implantable electronic devices (CIEDs). However, whether the incidence of inappropriate shock increases in patients with S-ICDs and concomitant CIEDs remains unclear. This study aimed to investigate the association between the concomitant use of CIEDs and the incidence of inappropriate shock in patients with current-generation S-ICDs.

METHODS

A total of 127 consecutive patients received an S-ICD. Patients were assigned to two groups depending on concomitant use of CIEDs at the time of S-ICD implantation: patients without other CIEDs (non-combined group, 106 patients) and patients with other CIEDs (combined group, 21 patients). CIEDs included pacemakers, implantable cardioverter defibrillators, cardiac resynchronization therapy pacemakers, and cardiac resynchronization therapy defibrillators. The primary outcome was inappropriate shock, defined as a shock other than ventricular arrhythmia. Hazard ratios and 95% confidence intervals were calculated using a time-varying Cox proportional hazards model which was adjusted for age because age differed between the groups and could be a confounder.

RESULTS

During a median follow-up period of 2.2 years (interquartile range, 1.0-3.4 years), inappropriate shock events occurred in 17 (16%) and five (19%) patients of the non-combined and combined groups, respectively. While the age-adjusted hazard ratio for inappropriate shock was 24% higher in the combined than in the non-combined group (hazard ratio = 1.24, 95% confidence interval, 0.39-3.97), this difference was insignificant (p = .71).

CONCLUSION

The incidence of inappropriate shock did not differ between patients with and without concomitant use of CIEDs, suggesting that S-ICDs could potentially be combined with other CIEDs without increasing the number of inappropriate shocks. Further studies are warranted to confirm the safety and feasibility of concomitant use of S-ICDs and CIEDs.

Effects and Complications of Subcutaneous Implantable Cardioverter-Defibrillator in the Prevention of Sudden Cardiac Death: A Narrative Review

An implantable cardioverter-defibrillator (ICD) is one of those devices that is a big boom for the prevention of sudden deaths due to heart failure. This particular device has been in use for just a couple of years, but its impact in the domain has brought about a considerable change in the way a specific issue of the cardiovascular system is tackled. Although subcutaneous or hypodermic implantable cardioverter-defibrillator (S-ICD) is considered to be a better alternative as far as transvenous implantable cardioverter-defibrillator (TV-ICD) is concerned, the former, being a newer introduction in the market, needs to be assessed in depth to clearly understand its effects and complications. Various types of research have been conducted on the efficacy of this device, and in most of the studies, the supremacy of this device is clearly evident when compared with other devices that are used for the same purpose. Better innovations in subcutaneous or hypodermic implantable cardioverter-defibrillators would enable them to be manufactured in a more efficient and cost-effective way so that a huge lot of people are benefited from this device. This review article is a whole peep into the various studies done in this domain, thereby providing adequate scientific insights about subcutaneous or hypodermic implantable cardioverter-defibrillators in a very simple and comprehensive manner.

Pro-Con Debate: Are Patients With a Cardiovascular Implantable Electronic Device Suitable to Receive Care in a Free-Standing Ambulatory Surgery Center?

Migration of surgical and other procedures that require anesthesia care from a hospital to a free-standing ambulatory surgery center (ASC) continues to grow. Patients with cardiac implantable electronic devices (CIED) might benefit from receiving their care in a free-standing ASC setting. However, these patients have cardiovascular comorbidities that can elevate the risk of major adverse cardiovascular events. CIEDs are also complex devices and perioperative management varies between devices marketed by various manufacturers and require consultation and ancillary services, which may not be available in a free-standing ASC. Thus, perioperative care of these patients can be challenging. Therefore, the suitability of this patient population in a free-standing ASC remains highly controversial. Although applicable advisories exist, considerable discussion continues with surgeons and other proceduralists about the concerns of anesthesiologists. In this Pro-Con commentary article, we discuss the arguments for and against scheduling a patient with a CIED in a free-standing ASC.

[Infections in interventional electrophysiology]

The implantation of pacemakers and defibrillators carries the highest risk of infection in interventional electrophysiology. The use of implantable cardiac devices is continually increasing with almost 2 million devices implanted worldwide each year. The recipients' profile may also be associated with an increased risk of infection. Several measures can be implemented to reduce the risk of device-related infection. Systematic antibiotic prophylaxis has proven to be beneficial provided that prescription modalities are respected, especially with respect to the selection of the appropriate molecule and timing of administration prior to the procedure. Despite all the precautions taken during surgery (asepsis, prophylactic antibiotic therapy….) the estimated rate of peri-procedural infection is around 2%. Device related infections are associated with a high rate of morbidity and mortality as well as substantial healthcare costs. Staphylococcus aureus (SA) and epidermidis (SE) are the pathogenic agents involved in most cases. Prevention is crucial given the difficulties in treating such infections because of the near-systematic need to remove the device and antibiotic resistance. Leadless pacemakers and subcutaneous defibrillators are potential alternatives to implantable endocardial devices, albeit with certain limitations. A group of experts has recently issued consensus paper on the prevention, diagnosis and treatment of infections associated with endocardial implantable cardiac devices.

A Recurrent Exertional Syncope and Sudden Cardiac Arrest in a Young Athlete with Known Pathogenic p.Arg420Gln Variant in the RYR2 Gene

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is one of causes of sudden cardiac death in the young, especially in athletes. Diagnosis of CPVT may be difficult since all cardiological examinations performed at rest are usually normal, and exercise stress test-induced ventricular tachycardia is not commonly present. The identification of a pathogenic mutation in RYR2 or CASQ2 is diagnostic in CPVT. We report on a 20-year-old athlete who survived two sudden cardiac arrests during swimming. Moreover, he suffered repeated syncopal spells on exercise. The diagnosis was made only following genetic testing using a multi-gene panel, and the p.Arg420Gln RYR2 variant was identified. We present diagnostic and therapeutic issues in this young athlete with CPVT.