Shocks after implantable cardioverter-defibrillator implantation in idiopathic cardiomyopathy patients: a myocardial biopsy study

Abstract

Prediction of follow-up shock is crucial to stratify patients with dilated cardiomyopathy (DCM) requiring implantable cardioverter defibrillator (ICD). The objective of the article is to assess the predictive value of endo-myocardial biopsy (EMB) towards ICD shock and follow-up mortality. A series of patients with DCM scheduled for ICD implantation underwent EMB to further determine the genesis of DCM. Presence of fibrosis and inflammation was documented and related to outcomes. A total of 240 patients were referred for ICD as primary (56%) and secondary (44%) prophylaxis. EMB showed myocardial fibrosis in 55.4%, inflammation in 55.7%, and viral genomic material in 60%. Median follow-up was 39 months (1-209). Appropriate and inappropriate shocks occurred in 29.2 and 20.4%. At logistic regression, determinants of appropriate shock were ICD indication for secondary prophylaxis (direct relationship: p = 0.009, OR 3.4, CI 1.3-8.8) and presence of inflammation at EMB (inverse relationship: p = 0.04, OR 0.4, CI 0.1-0.9). Moreover, the sole determinant of inappropriate shock was age at implant (inverse relationship: p = 0.003, OR = 0.9, CI 0.90-0.98). Overall mean estimated survival was 168 months and 5-year survival was 83%. Degree of improvement in LVEF% was the sole determinant of follow-up mortality (inverse relationship p = 0.02; HR = 0.9; CI 0.88-0.99). Present selection criteria for ICDs implant rely mainly on LVEF% that lacks sensitivity and specificity. EMB can identify the substrate of increased or reduced life-threatening arrhythmias. Presence of inflammation is a positive prognostic factor for reduced arrhythmogenic risk, independently by the ICD implantation indication.

Selvester score predicts implantable cardioverter defibrillator shocks in patients with non‐ischemic cardiomyopathy

“…In the cardiac MRI study carried out by Wu et al, it was reported that myocardial scar tissue increased the frequency of ICD shock in NICMP 11 . The study conducted by Safak et al stated that the presence of inflammation was decisive in endomyocardial biopsy in idiopathic cardiomyopathy patients in appropriate ICD shocks 23 . Also it has been showed that inflammation, and myocardial stretch, is associated with myocardial damage and fibrosis which predispose arrhythmias.…”

Cardioverter-defibrillators in patients with dilated cardiomyopathy syndrome: predictors of appropriate shocks and influence on the outcomes

“…(2018 г.) у пациентов с признаками активного миокардита, по данным ЭМБ, частота оправданных срабатываний оказалась достоверно меньше, чем при его отсутствии (p=0,04), что свидетельствует о том, что при активном миокардите у большинства пациентов торопиться с имплантацией ИКД не стоит [31]. В нашем исследовании при изолированном миокардите срабатывание дефибриллятора зарегистрировано лишь в одном случае, существенно большее число шоков отмечалось при сочетании генетической кардиомиопатии и миокардита (70%).…”

Indications for Implantation and Efficiency of Cardioverter-Defibrillators in Patients With Dilated Cardiomyopathy

“…В то же время в работе H-P. Schultheiss (2018) и соавт. у пациентов с признаками активного миокардита, по данным ЭМБ, частота оправданных срабатываний оказалась статистически значимо меньше, чем при его отсутствии (p=0,04), что свидетельствует о том, что в острый период в большинстве случаев не стоит торопиться с имплантацией [21].…”