Personalized Management of Sudden Death Risk in Primary Cardiomyopathies: From Clinical Evaluation and Multimodality Imaging to Ablation and Cardioverter-Defibrillator Implant

Sudden cardiac death represents the leading cause of death worldwide; although the majority of sudden deaths occur in an elderly population with coronary artery disease, some occur in young and otherwise healthy individuals, as is the case of cardiomyopathies. The aim of the present review is to provide a stepwise hierarchical approach for the global sudden death risk estimation in primary cardiomyopathies. Each individual risk factor is analyzed for its contribution to the overall risk of sudden death for each specific cardiomyopathy as well as across all primary myocardial diseases. This stepwise hierarchical and personalized approach starts from the clinical evaluation, subsequently passes through the role of electrocardiographic monitoring and multimodality imaging, and finally concludes with genetic evaluation and electro-anatomical mapping. In fact, the sudden cardiac death risk assessment in cardiomyopathies depends on a multiparametric approach. Moreover, current indications for ventricular arrhythmia ablation and defibrillator implantation are discussed.

Reduction in Ventricular Tachyarrhythmia Burden in Patients Enrolled in the RAID Trial

BACKGROUND

The RAID (Ranolazine Implantable Cardioverter-Defibrillator) randomized placebo-controlled trial showed that ranolazine treatment was associated with reduction in recurrent ventricular tachycardia (VT) requiring appropriate implantable cardioverter-defibrillator (ICD) therapy.

OBJECTIVES

This study aimed to identify groups of patients in whom ranolazine treatment would result in the highest reduction of ventricular tachyarrhythmia (VTA) burden.

METHODS

Andersen-Gill analyses were performed to identify variables associated with risk for VTA burden among 1,012 patients enrolled in RAID. The primary endpoint was VTA burden defined as VTA episodes requiring appropriate treatment.

RESULTS

Multivariate analysis identified 7 factors associated with increased VTA burden: history of VTA, age ≥65 years, New York Heart Association functional class ≥III, QRS complex (≥130 ms), low ejection fraction (<30%), atrial fibrillation (AF), and concomitant antiarrhythmic drug (AAD) therapy. The effect of ranolazine on VTA burden was seen among patients without concomitant AAD therapy (HR [HR]: 0.68; 95% CI: 0.55-0.84; P < 0.001), whereas no effect was seen among those who are concomitantly treated with other AADs (HR: 1.33; 95% CI: 0.90-1.96; P = 0.16); P = 0.003 for interaction. In patients with cardiac resynchronization therapy (CRT) ICDs, ranolazine treatment was associated with a 36% risk reduction for VTA recurrence (HR: 0.64; 95% CI: 0.47-0.86; P < 0.001), whereas among patients with ICDs without CRT no significant effect was noted (HR: 0.94; 95% CI: 0.74-1.18; P = 0.57); P = 0.047 for interaction.

CONCLUSIONS

In patients with high risk for VTA, ranolazine is effective in reducing VTA burden, with significantly greater effect in CRT-treated patients, those without AF, and those not treated with concomitant AADs. In patients already on AADs or those with AF, the addition of ranolazine did not affect VTA burden. (Ranolazine Implantable Cardioverter-Defibrillator Trial [RAID]; NCT01215253).

Transient Asystole From Pacing Inhibition During Percutaneous Coronary Intervention

A 68-year-old man with a biventricular implantable cardioverter-defibrillator who was pacemaker dependent was admitted for percutaneous coronary intervention. The patient had an asystolic cardiac arrest as a result of electromagnetic interference during an orbital atherectomy. We should keep electromagnetic interference from the machine in mind when performing orbital atherectomy. (Level of Difficulty: Beginner.)

The IC-D score for predicting prophylactic cardioverter-defibrillator implantation following acute myocardial infarction

BACKGROUND

A reduced left ventricular ejection fraction (LVEF) ≤35% ≥6 weeks following an acute myocardial infarction (MI) may indicate prophylactic implantation of a cardioverter-defibrillator (ICD). We sought to find predictors of absence of significant left ventricular (LV) remodeling post-MI.

METHODS

All consecutive patients hospitalized for acute MI with an LVEF ≤35% at discharge in our institution from 2010 were retrospectively included. Patients were assigned to two groups according to the persistence of an LVEF ≤35% (ICD+) or a recovery >35% (ICD-). Logistic regression was performed to build a predictive score, which was then externally validated.

RESULTS

Among a total of 1533 consecutive MI patients, 150 met inclusion criteria, 53 (35%) in the ICD+ group and 97 in the ICD group. After multivariable analyses, an LVEF ≤25% at discharge (adjusted OR 6.23 [2.47 to 17.0], p < .0001) and a CPK peak at the MI acute phase >4600 UI/L (adjusted OR 9.99 [4.27 to 25.3], p < .0001) both independently predicted non-recovery at 6 weeks. The IC-D (Increased Cpk-LV Dysfunction) score predicted persistent LVEF ≤35% with areas under curve of 0.83 and 0.73, in the study population and in a multicenter validation cohort of 150 patients, respectively (p < .0001).

CONCLUSIONS

The association of a severely reduced LVEF and a major release of myocardial necrosis biomarkers at the acute phase of MI predict unfavorable remodeling, and prophylactic ICD implantation.

Detection and management of arrhythmias in peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is an idiopathic dilated cardiomyopathy, in which previously healthy women present with heart failure secondary to left ventricular (LV) systolic dysfunction during the last months of pregnancy or up to 5 months postpartum. PPCM occurs worldwide. The incidence seems to be increasing, possibly due to increasing awareness of the condition and diagnosis thereof. Women diagnosed with PPCM present with symptoms and signs of heart failure, thromboembolism or arrhythmia. Although the incidence of arrhythmias in this condition is not well documented, patients with PPCM often have rhythm disturbances. Indeed, life-threating arrhythmias contribute significantly to sudden cardiac death (SCD) in this population, especially when patients have poor systolic function. In this review, we summarize the evidence on atrial and ventricular arrhythmias in PPCM, as detected by various diagnostic modalities. Furthermore, we summarize the management of arrhythmias in PPCM, as recommended by contemporary guidelines.

Transvenous extraction of 3-year-old Seldinger guide wire lost in venous system and causing superior vena cava syndrome - rare complication of implantable cardioverter-defibrillator implantation

A 65-year-old male patient underwent left-sided placement of implantable cardioverter-defibrillator. At three years after implantation he emerged complaining on left upper limb and left-sided neck edema. Left brachicephalic vein thrombosis due to device leads was recognized. The attending cardiologist referred the patient to university radiology department for venous angioplasty but the patient was admitted to cardiology department. Coronary angiography was performed due to suspicion of ischemic heart disease. However, it showed the presence of foreign body in cardiovascular system - completely intravascular round-tipped guide wire used in Seldinger technique for insertion of the endocardial lead abandoned in left subclavian vein and reaching to superior vena cava. Patient was transferred to third-degree reference lead extraction center. The procedure was performed under general anesthesia in hybrid operating room. Via femoral vein access we introduced Needle's Eye Snare and grasped the guide wire. Then, using polytetrafluoroethylene sheath the tissue adhesions were dissected and the complete guide wire was retrieved.

Characteristic of fibrotic myocardial lesions associated with life-threatening ventricular tachyarrhythmias in patients with ischemic and non-ischemic cardiomyopathies

AIM

To identify the features of myocardial scar and fibrosis associated with the occurrence of malignant ventricular tachyarrhythmias (VTs) in high-risk patients with ischemic (ICMP) and non-ischemic cardiomyopathy (NICMP).

MATERIALS AND METHODS

This prospective study included 50 patients (41 men, 9 women), age = 60 ± 13 years, 30 patients of them with ICMP and 20 patients with NICMP, who underwent echocardiography (Echo) and contrast magnetic resonance imaging (MRI) of the heart followed by implantation of cardioverter-defibrillators (ICD) or resynchronizing devices with defibrillator (CPTD) to prevent sudden cardiac death.

RESULTS

Sustained VTs were reported in 20/30 (67%) patients with ICMP and in 5/20 (25%) patients with NICMP on follow-up [26 (22-37) months]. Successive univariate and ROC-analyses of Echo and MRI-indices between patients with and without recurrence of VTs found different results for ICMP and NICMP patients groups. In ICMP patients the VTs were associated with wide transmural fibrosis on contrast MRI that covered 3 or more segments of left ventricular. These segments were preferably localized in the middle parts of the inferior and inferolateral segments of the left ventricle. The independent predictors of VTs in NICMP patients were non-transmural fibrosis at 4.5% of the left ventricular mass by contrast MRI as well as low left ventricular ejection fraction (less than 26%) by Echo.

CONCLUSION

To determine the indications for implantation of the ICD and CRTD for primary prevention of sudden cardiac death, it is advisable to take into account not only the value of ejection fraction of left ventricular, but also the features of the fibrosis of the left ventricle by contrast MRI of the heart.

Implantable cardioverter defibrillator does not cure the heart

A man with non-ischemic cardiomyopathy, EF 22%, permanent AF and ICD was admitted for elective device replacement. The need for the optimization of the ventricular rate and avoidance of right ventricular pacing made it necessary to up-grade the existing pacing system using direct His bundle pacing and dual chamber ICD. This enabled the regularization of ventricular rate, avoiding the RV pacing and optimize the beta-blocker dose. The one month follow-up already showed reduction in left ventricle diameter, improvement in ejection fraction, NYHA class decrease to II. The His bundle pacing enabled the optimal treatment of the patient resulting in excellent clinical improvement.

The impact of remote monitoring of implanted cardioverter-defibrillator (ICD) and cardiac resynchronisation therapy device (CRT-D) patients on healthcare costs in the Silesian population: three-year follow-up

BACKGROUND

The population of patients with implanted cardioverter-defibrillators (ICD) and cardiac resynchronisation therapy devices (CRT-D) is constantly growing. The use of remote-monitoring (RM) techniques in this group can significantly improve clinical outcomes, but there are limited data about the impact of RM on healthcare costs from a payer's perspective.

AIM

The aim of the study was to assess the impact on costs for the healthcare system of RM in patients with ICD or CRT-D.

METHODS

We examined a cohort of 842 patients with ICD or CRT-D. The group was divided into two groups based on RM (or no RM [NRM]), matched according to important clinical characteristics. The subjects were followed for a maximum of three years after implantation (mean follow-up 2.11 ± 0.83 years). The overall costs for the healthcare provider in the follow-up were defined as the primary endpoint. The secondary endpoint was the use of different types of medical contact events: hospitalisation and number of in-clinic and general practitioner visits (without the number of remote transmissions).

RESULTS

In the three-year follow-up, the reduction in the costs of treatment for National Health Care in the RM group was 33.5% (median value, p < 0.001). In patients with implanted CRT-D, the reduction reached 42.7% (p = 0.011), and with ICD it was 31.3% (p = 0.007). We observed no significant reduction in the median hospitalisation costs in the three-year follow-up in the RM group (p = NS), despite a 25% drop in the mean value. The costs of outpatient visits were slightly higher in the RM group (p = NS). In the follow-up period, there was no reduction in the number of medical contact events (p = NS).

CONCLUSIONS

Remote monitoring in patients with implanted ICD or CRT-D devices reduces the cost for the national healthcare provider.

Complications in recipients of cardioverter-defibrillator or cardiac resynchronization therapy: Insights from Silesian Center Defibrillator registry

BACKGROUND

Current real-life information from all-comers registries from middle and east Europe about the incidence and type of complications during long-term follow-up of patients with cardioverters-defibrillators (ICD) and cardiac resynchronization devices-defibrillators (CRT-D) is still insufficient. The aim of the study was to assess the incidence and determinants of short- and long-term complications related to implantable ICD and CRT-D.

METHODS

We studied 1,105 recipients hospitalized in our center in 2009-2013, followed for a mean of 2.4 years (total of 2,652 patient-years). The independent association between ICD and CRT-D recipients' and implantation-procedures' characteristics with the incidence of complications was analyzed using multivariable Cox regression analysis.

RESULTS

In 2-month post-procedural period, 124 (11.2%) patients developed complications. Independent predictors of short-term complications (within 2 months) were: atrial fibrillation, dual chamber ICD implantation, and use of antiplatelet therapy or coumarin. Twenty-seven (2.44%) patients experienced complications, mostly lead-related (n = 21). Independent predictors of long-term complications (2-12 months after implantation) were atrial fibrillation and dual chamber ICD implantation.

CONCLUSIONS

Despite significant technological progress and operators' experience, the occurrence of complications in ICD and CRT-D recipients is still substantial. Majority of complications are recorded in the early post-implantation phase. Analysis of independent predictors of complications seem to be essential in helping to reduce adverse events in the future and strongly supports the need for routine follow-up.

Candida and cardiovascular implantable electronic devices: a case of lead and native aortic valve endocarditis and literature review

Use of cardiovascular implantable electronic devices (CIED), including permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), has increased dramatically over the past two decades. Most CIED infections are caused by staphylococci. Fungal causes are rare and their prognosis is poor. To our knowledge, there has not been a previously reported case of multifocal Candida endocarditis involving both a native left-sided heart valve and a CIED lead. Here, we report the case of a 70-year-old patient who presented with nausea, vomiting, and generalised fatigue, and was found to have Candida glabrata endocarditis involving both a native aortic valve and right atrial ICD lead. We review the literature and summarise four additional cases of CIED-associated Candida endocarditis published from 2009 to 2014, updating a previously published review of cases prior to 2009. We additionally review treatment guidelines and discuss management of CIED-associated Candida endocarditis.