Risk factors for sudden cardiac death to determine high risk patients in specific patient populations that may benefit from a wearable defibrillator

Abstract

BACKGROUND There is a high risk for sudden cardiac death (SCD) in certain patient groups that would not meet criteria for implantable cardioverter defibrillator (ICD) therapy. In conditions such as hypertrophic cardiomyopathy (HCM) there are clear risk scores that help define patients who are high risk for SCD and would benefit from ICD therapy. There are however many areas of uncertainty such as certain patients post myocardial infarction (MI). These patients are high risk for SCD but there is no clear tool for risk stratifying such patients. AIM To assess risk factors for sudden cardiac death in major cardiac disorders and to help select patients who might benefit from Wearable cardiac defibrillators (WCD). METHODS A literature search was performed looking for risk factors for SCD in patients post-MI, patients with left ventricular systolic dysfunction (LVSD), HCM, long QT syndrome (LQTS). There were 41 studies included and risk factors and the relative risks for SCD were compiled in table form. RESULTS We extracted data on relative risk for SCD of specific variables such as age, gender, ejection fraction. The greatest risk factors for SCD in post MI patients was the presence of diabetes [Hazard ratio (HR) 1.90-3.80], in patient with LVSD was ventricular tachycardia (Relative risk 3.50), in LQTS was a prolonged QTc (HR 36.53) and in patients with HCM was LVH greater than 20 mm (HR 3.10). A proportion of patients currently not suitable for ICD might benefit from a WCD CONCLUSION There is a very high risk of SCD post MI, in patients with LVSD, HCM and LQTS even in those who do not meet criteria for ICD implantation. These patients may be candidates for a WCD. The development of more sensitive risk calculators to predict SCD is necessary in these patients to help guide treatment.

No beneficial use of the wearable cardioverter defibrillator among patients suffering from inherited and congenital heart disease: data from a European multicenter registry

“…Long-QT syndrome has an absolute SCD risk of 4.9%–13% ( 18 ) and has a heightened risk for Torsade de Pointes tachycardia ( 2 ). In 13% of patients, a sudden cardiac arrhythmia or death occurs before age 40.…”

Effective treatment of electrical storm by a wearable cardioverter defibrillator in a patient with severely impaired left ventricular function after myocardial infarction: a case report

“…Forty-eight percent of patients with a WCD suffer from sleep disturbance and feel disabled in daily routine activities. Despite this, a WCD should be offered to motivated high-risk patients after individual consideration of the risk factors according to the guidelines [ 2 , 9 ]. Additionally, improved and close monitoring of WCD patients by telemedicine might increase acceptance and quality of life in affected patients [ 19 ].…”

Implantable Cardioverter-Defibrillator for Primary Prevention in Asia

“… 60 , 61 Male sex also carries a high risk and was shown to double the risk when compared with female sex. 62 , 63 Positive family history of SCD as well as smoking history or current smoking were also reported to be independent risk factors for malignant VTA and SCD. 64 , 65 One important risk factor that should always be sought (including the performance of prolonged cardiac monitoring), is the presence as well as the burden of NSVT.…”