Implantable Cardioverter-Defibrillators for Secondary Prevention of Sudden Cardiac Death: A Review

Nanoscale piezoelectric patches preserve electrical integrity of infarcted hearts

Ischemic heart disease is the leading cause of death worldwide. Several approaches have been explored to restore cardiac function, however few investigated new strategies to improve electrical functional recovery. Herein, we have investigated the impact of piezoelectric patches (Piezo patches), capable of generating electric charges upon mechanical deformation, on rat cardiac slices, healthy and ischemic hearts (ex vivo), on infarcted mice (in vivo) and on healthy and infarcted pigs (in vivo). Piezo patches did not preclude cardiac slice contractility, while compared with electrically inert control patches. In addition, Piezo patches showed an adequate safety profile in a working heart model as no electrophysiologic alterations were detected in healthy hearts. Epicardial implantation of Piezo patches in acutely infarcted mice hearts significantly improved myocardial electrical integrity without disturbing systolic function. Moreover, Piezo patches partially prevented ischemia-related adverse cardiac remodeling, reducing left ventricular chamber dilatation and compensatory hypertrophy. Coherently, Piezo patch-implanted hearts revealed downregulation of genes associated with extracellular matrix remodeling. Importantly, in vivo implantation of Piezo patches in porcine hearts revealed to be electrically safe as no major effects in its electrophysiology were detected. Overall, the results presented here endorse Piezo patches as a promising therapeutic strategy to improve post-myocardial infarction structural and electrical remodeling.

Comparison of Single-Coil Versus Dual-Coil Implantable Cardioverter Defibrillator Devices: A Systematic Review and Meta-Analysis of Efficacy and Extraction-Related Outcomes

BACKGROUND

Implantable cardioverter defibrillators (ICD) are battery-operated devices used to manage irregular heart rhythms and deliver therapeutic shocks to the heart. This updated systematic review and meta-analysis compares the efficacy and extraction-related outcomes of single-coil versus dual-coil ICDs in view of conflicting data.

METHODS

Several databases, including PubMed, Cochrane Library, and Google Scholar, were comprehensively explored dating from inception to April 1, 2024. Data were compared using odds ratio (OR), hazard ratio (HR), and mean differences (MD). A value of p < 0.05 indicated statistical significance.

RESULTS

Ultimately, 28 studies were included in this quantitative synthesis. Defibrillation threshold (DFT) indicated statistical superiority in the dual-coil cohort (MD: 0.58; 95% confidence interval [CI]: 0.07-1.09; p = 0.03). In addition, all-cause mortality was significantly elevated in the dual-coil cohort (HR: 0.91; 95% CI: 0.87-0.97; p = 0.001). Furthermore, implant time was significantly lower in the single-coil group (MD: -7.44; 95% CI: -13.44 to -1.43; p = 0.02). Other outcomes, including first shock efficacy, cardiac mortality, post-extraction major complications, post-extraction procedural success, and post-extraction mortality, did not demonstrate any significant statistical differences.

CONCLUSION

In conclusion, despite the desirable safety profile of single-coil ICDs, the use of dual-coil ICDs continues to hold merit due to their superior efficacy and advanced sensing capabilities, especially in complex cases. In addition, the perceived risk of a greater adverse profile in dual-coil lead extraction can be refuted by preliminary aggregate results generated within this meta-analysis. However, further robust studies are warranted before arriving at a valid conclusion.

Application prospect of speckle tracking echocardiography in pacemaker implantation

More than 1 million permanent pacemakers are implanted worldwide each year, half of which are in patients with high-grade atrioventricular block. Pacemakers provide adequate frequency support in the initial stage, but traditional right ventricular (RV) pacing may lead to or aggravate left ventricular dysfunction and arrhythmia. Several potential risk factors for heart failure and arrhythmias after pacemaker surgery have been identified, but their occurrence remains difficult to predict clinically. Compared with RV pacing, His bundle pacing (HBP) and left bundle branch pacing (LBBP) activate the intrinsic His-Purkinje conduction system and provide physiological activation, but whether HBP and LBBP also cause ventricular mechanical dyssynchrony remains uncertain. The implantation of cardiac resynchronization therapy and implantable cardioverter defibrillator depends on left ventricular ejection fraction (LVEF). LVEF This depends on volume changes and is less reproducible. Speckle tracking echocardiography (STE) is a technique that can accurately quantify the degree and duration of systolic deformation. STE detects changes in myocardial function more sensitively than traditional measures of diastolic and systolic function, including LVEF. Clinicians can evaluate myocardial strain and synchrony based on strain (percent change in segmental length from baseline) and strain rate (strain per unit time). This review and case series investigate the clinical use of speckle tracking echocardiography in pacemaker implantation.

Long-term outcomes among out-of-hospital cardiac arrest survivors with reversible vs. non-reversible causes

AIMS

A reversible cause of out-of-hospital cardiac arrest (OHCA) is vaguely defined in international guidelines as an identifiable transient or potentially correctable condition. However, studies evaluating long-term outcomes of patients experiencing OHCA due to reversible and non-reversible causes are lacking. We aimed to determine differences in long-term outcomes in OHCA survivors according to different aetiology.

METHODS AND RESULTS

From the British Columbia Cardiac Arrest registry, adults with non-traumatic OHCA (2009-2016) surviving to hospital discharge were identified. Patients were categorized by OHCA aetiology combining reversibility and underlying ischaemic aetiology. The primary outcome was a composite of all-cause mortality, recurrent OHCA, or re-hospitalization for sudden cardiac arrest or ventricular arrhythmias. Using the Kaplan-Meier method and multivariable Cox regression models, we compared the risk of the composite outcome according to different OHCA aetiology. Of 1325 OHCA hospital-discharge survivors (median age 62.8 years, 77.9% male), 431 (32.5%) had reversible ischaemic, 415 (31.3%), non-reversible ischaemic, 99 (7.5%), reversible non-ischaemic, and 380 (28.7%), non-reversible non-ischaemic aetiologies. At 3 years post discharge, the Kaplan-Meier event-free rate was highest in patients with a reversible ischaemic aetiology [91%, 95% confidence interval (CI) 87-94%], and lowest in those with a reversible non-ischaemic aetiology (62%, 95% CI 51-72%). In multivariate analyses, compared with non-reversible non-ischaemic cause, reversible ischaemic cause was associated with a significantly lower hazard ratio (HR; 0.52, 95% CI 0.33-0.81), reversible non-ischaemic cause with a significantly higher HR (1.53, 95% CI 1.03-2.32), and non-reversible ischaemic cause with a non-significant HR (0.92, 95% CI 0.64-1.33) for the composite outcome.

CONCLUSION

Compared to other aetiologies, the presence of a reversible ischaemic cause is associated with improved long-term OHCA outcomes.

Analysis of ionizing radiation doses received by patients during electrocardiological procedures

Medical procedures in the field of electrocardiology belong to a large group of cardiological procedures. Performing them involves exposure to ionizing radiation. In this study, five medical procedures in the field of electrocardiology performed in three medical facilities were analyzed in terms of patients' exposure to ionizing radiation. A total of 178 patients were analyzed. Depending on the type of procedure, the recorded doses ranged from 7.4 to 614.62 mGy. The majority of electrocardiological procedures are pacemaker implantations 38% and RF ablation 33%. The results obtained show a significant dispersion of the recorded dose values in the same type of treatment. This is reflected, for example, in the high coefficient of variation for doses in RF ablation. The type of X-ray machine used during the procedure also influences the dose values. Although the exposure of patients undergoing electrocardiological procedures to ionizing radiation is much lower than in the case of cardiac vascular procedures, it may reach a similar level, especially in the case of implantation of devices regulating the correct functioning of the heart.

Advances and challenges in the diagnosis and management of left ventricular noncompaction in adults: A literature review

In the realm of cardiovascular health, isolated left ventricular noncompaction (LVNC) stands out for its distinct morphological features and the clinical challenges it presents, particularly in adults. This literature review explores the intricacies of LVNC, aiming to unravel its epidemiological spread, diagnostic hurdles, and therapeutic strategies. Despite technological advancements in cardiac imaging that have improved the recognition of LVNC, a significant gap persists alongside a fragmented understanding of its pathogenesis. The studies scrutinized reveal a broad spectrum of prevalence rates influenced by diverse diagnostic tools and demographic variables. This variation underscores the complexity of accurately identifying LVNC and the resultant implications for clinical management. The review succinctly addresses the need for precise guidelines to navigate the diagnosis of LVNC and outlines the imperative for tailored clinical management approaches that cater to the wide array of patient presentations, from asymptomatic cases to those with severe cardiac dysfunction. By highlighting the critical gaps in current literature-namely the absence of standardized diagnostic criteria and a comprehensive pathogenic model-the review sets the stage for future research directions. These endeavors are essential for enhancing diagnostic accuracy, refining management protocols, and ultimately improving patient outcomes in this complex subset of cardiomyopathy, thus contributing significantly to the advancement of cardiovascular medicine.

The Plumber Versus Electrician Dilemma: To Bypass or to Defibrillate?

We present a unique case of an 80-year-old male who presented to our emergency department following cardiac defibrillation when he was found to be in polymorphic ventricular tachycardia (VT) after a syncopal event while at cardiac rehabilitation. He had known coronary artery disease and had a four-vessel coronary artery bypass graft (CABG) 20 years prior to presentation. He underwent left heart catheterization (LHC) two months prior to the syncopal event for worsening shortness of breath and the decision at that time was to proceed with medical management and intervene with redo-CABG if shortness of breath did not improve or progressively worsened. While admitted under our care after the polymorphic VT event, we faced the dilemma of whether to proceed with redo-CABG first since cardiac ischemia is a common cause of polymorphic VT or whether to insert an implantable cardioverter-defibrillator (ICD) before proceeding with redo-CABG. We present the current literature that addresses ICD implantation for secondary prevention and our approach to this complicated case.

Predictors of mortality and clinical outcomes following implantable cardioverter-defibrillator therapy in elderly patients: A retrospective single-center cohort study

Background and aims

Implantable cardioverter-defibrillators (ICDs) are frequently used to prevent sudden cardiac death in patients with high-risk arrhythmias. However, the use of ICD therapy in elderly patients beyond the predicted age of life expectancy is still controversial. We aimed to evaluate the predictors of mortality and clinical outcomes following ICD implantation in elderly patients.

Methods

We conducted a retrospective analysis of 145 elderly patients aged 72 years and older who received ICD implantation between January 2010 and August 2015. We collected and analyzed baseline data, including clinical, demographic, and medical history, the reason for ICD therapy, procedural data, and echocardiography results. Follow-up data included the development of complications and mortality. The predictors of mortality were identified using the univariate and multivariable Cox regression models.

Results

During the median follow-up duration of 30.5 [18.0-48.0] months, 141 cases completed follow-up (mean age = 76.0 ± 3.7 years). Forty-four patients experienced at least one episode of ICD therapy. Inappropriate shock, recurrent shock, and device-related infection were the most frequent complications observed in our study. Of the 145 patients, 42 died during the follow-up period, with an average survival time of 22.4 months after ICD implantation. Among these patients, 11 received ICD for primary prevention, and 31 received it for secondary prevention. Cardiovascular problems were the leading cause of death. We found that a low baseline ejection fraction (EF) was an independent predictor of mortality (hazard ratio = 0.93, 95% confidence interval: 0.90-0.98; p = 0.008).

Conclusion

Our study suggests that ICD therapy is a valuable treatment option for elderly patients beyond their predicted age of life expectancy. The study highlights the importance of baseline EF as a significant predictor of mortality in these patients.

Overview of Cardiac Arrhythmias and Treatment Strategies

Maintenance of normal cardiac rhythm requires coordinated activity of ion channels and transporters that allow well-ordered propagation of electrical impulses across the myocardium. Disruptions in this orderly process provoke cardiac arrhythmias that may be lethal in some patients. Risk of common acquired arrhythmias is increased markedly when structural heart disease caused by myocardial infarction (due to fibrotic scar formation) or left ventricular dysfunction is present. Genetic polymorphisms influence structure or excitability of the myocardial substrate, which increases vulnerability or risk of arrhythmias in patients. Similarly, genetic polymorphisms of drug-metabolizing enzymes give rise to distinct subgroups within the population that affect specific drug biotransformation reactions. Nonetheless, identification of triggers involved in initiation or maintenance of cardiac arrhythmias remains a major challenge. Herein, we provide an overview of knowledge regarding physiopathology of inherited and acquired cardiac arrhythmias along with a summary of treatments (pharmacologic or non-pharmacologic) used to limit their effect on morbidity and potential mortality. Improved understanding of molecular and cellular aspects of arrhythmogenesis and more epidemiologic studies (for a more accurate portrait of incidence and prevalence) are crucial for development of novel treatments and for management of cardiac arrhythmias and their consequences in patients, as their incidence is increasing worldwide.

Machine Learning-Based Phenomapping in Patients with Heart Failure and Secondary Prevention Implantable Cardioverter-Defibrillator Implantation: A Proof-of-Concept Study

Background

Previous studies have failed to implement risk stratification in patients with heart failure (HF) who are eligible for secondary implantable cardioverter-defibrillator (ICD) implantation. We aimed to evaluate whether machine learning-based phenomapping using routinely available clinical data can identify subgroups that differ in characteristics and prognoses.

Methods

A total of 389 patients with chronic HF implanted with an ICD were included, and forty-four baseline variables were collected. Phenomapping was performed using hierarchical k-means clustering based on factor analysis of mixed data (FAMD). The utility of phenomapping was validated by comparing the baseline features and outcomes of the first appropriate shock and all-cause death among the phenogroups.

Results

During a median follow-up of 2.7 years for device interrogation and 5.1 years for survival status, 142 (36.5%) first appropriate shocks and 113 (29.0%) all-cause deaths occurred. The first 12 principal components extracted using the FAMD, explaining 60.5% of the total variability, were left for phenomapping. Three mutually exclusive phenogroups were identified. Phenogroup 1 comprised the oldest patients with ischemic cardiomyopathy; had the highest proportion of diabetes mellitus, hypertension, and hyperlipidemia; and had the most favorable cardiac structure and function among the phenogroups. Phenogroup 2 included the youngest patients, mostly those with non-ischemic cardiomyopathy, who had intermediate heart dimensions and function, and the fewest comorbidities. Phenogroup 3 had the worst HF progression. Kaplan-Meier curves revealed significant differences in the first appropriate shock (p = 0.002) and all-cause death (p < 0.001) across the phenogroups. After adjusting for medications in Cox regression, phenogroups 2 and 3 displayed a graded increase in appropriate shock risk (hazard ratio [HR] 1.54, 95% confidence interval [CI] 1.03-2.28, p = 0.033; HR 2.21, 95% CI 1.42-3.43, p < 0.001, respectively; p for trend < 0.001) compared to phenogroup 1. Regarding mortality risk, phenogroup 3 was associated with an increased risk (HR 2.25, 95% CI 1.45-3.49, p < 0.001). In contrast, phenogroup 2 had a risk (p = 0.124) comparable with phenogroup 1.

Conclusions

Machine-learning-based phenomapping can identify distinct phenotype subgroups in patients with clinically heterogeneous HF with secondary prophylactic ICD therapy. This novel strategy may aid personalized medicine for these patients.

Clinical Course and Outcomes in Patients with Left Ventricular Dysfunction Due to Myocardial Infarction After Kawasaki Disease

Long-term outcomes of patients with left ventricular dysfunction after Kawasaki disease (KD) remain unknown. The clinical course of 37 patients (29 males 8 females) with left ventricular ejection function (LVEF) less than 45% after KD since 1978 was retrospectively investigated. Cardiac events in this study were defined as admissions because of heart failure, fatal ventricular arrhythmias, heart transplantation, and death. Their ages when evaluated ranged from 1 to 70 years (median 35 years). The onset of KD ranged from 2 months to 20 years (median 21 months). All patients had bilateral coronary artery lesions, and multi-vessel occlusion occurred in 31 patients (84%). Previous myocardial infarction (MI) was found in 28 patients (76%). The interval from the onset of acute KD to the initial MI ranged from 15 days to 25 years (median 3 months). Reperfusion therapy was successful in 6 patients (30%), and coronary artery bypass grafting was performed in 23 patients (62%). Non-sustained ventricular tachycardia and fatal ventricular arrhythmias were detected in 11 patients and 22 patients, respectively. There were 15 deaths (41%). The 20-year and 50-year survival rates after KD were 84% (95% CI 67-92) and 54% (34-73), respectively (n = 37). The 30-year cardiac event-free rate after the detection of low LVEF was 42% (95% CI 27-59). The cutoff point of the left ventricular end-diastolic dimension for cardiac events was 65 mm. Patients with low LVEF had fatal ventricular arrhythmias and a worsening of their ischemic cardiomyopathy after 30 years of age and their outcomes were poor.

miR-3113-5p, miR-223-3p, miR-133a-3p, and miR-499a-5p are sensitive biomarkers to diagnose sudden cardiac death

Background

Sudden cardiac death (SCD) remains a great health threat and diagnostic challenge, especially those cases without positive autopsy findings. Molecular biomarkers have been urgently needed for the diagnosis of SCD displaying negative autopsy results. Due to their nature of stability, microRNAs (miRNAs) have emerged as promising diagnostic biomarkers for cardiovascular diseases.

Methods

This study investigated whether specific cardio-miRNAs (miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p) could serve as potential biomarkers for the diagnosis of SCD. Thirty-four SCD cases were selected, 18 categorized as SCD with negative autopsy (SCD-negative autopsy) findings and 16 as SCD with positive autopsy (SCD-positive autopsy) findings such as coronary atherosclerosis and gross myocardial scar. Carbon monoxide (CO) intoxication (n = 14) and fatal injury death (n = 14) that displayed no pathological changes of myocardium were selected as control group, respectively. Histological analyses were performed to reveal the pathological changes and real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression of those miRNAs.

Results

It showed that heart samples from the SCD-negative autopsy group displayed no remarkable difference with regard to the expression of cleaved-caspase3, CD31, and CD68 and the extent of fibrotic tissue accumulation when compared with control samples. The four cardio-miRNAs were significantly up-regulated in the SCD samples as compared with control. When discriminating SCD from controls, receiver operating characteristic (ROC) curve analysis revealed that the areas under the curve (AUC) of these 4 miRNAs were from 0.7839 to 0.9043 with sensitivity of 64.71–97.06% and specificity of 70–100%. Moreover, when discriminating the specific causes of SCD, the four miRNA expressions increased in the heart from the SCD-negative autopsy group as relative to that from the SCD-positive autopsy group, and a combination of two miRNAs presented higher diagnostic value (AUC = 0.7407–0.8667).

Conclusion

miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p may serve as independent diagnostic biomarkers for SCD, and a combination of two of these miRNAs could further discriminate detailed causes of SCD.

Anxiety and depression symptoms in Danish patients with an implantable cardioverter-defibrillator: prevalence and association with indication and sex up to 2 years of follow-up (data from the national DEFIB-WOMEN study)

AIMS

To investigate (i) the prevalence of anxiety and depression and (ii) the association between indication for implantable cardioverter-defibrillator (ICD) implantation and sex in relation to anxiety and depression up to 24 months' follow-up.

METHODS AND RESULTS

Patients with a first-time ICD, participating in the national, multi-centre, prospective DEFIB-WOMEN study (n = 1496; 18% women) completed the Hospital Anxiety and Depression Scale at baseline, 3, 6, 12, and 24 months. Data were analysed using linear mixed modelling for longitudinal data. Patients with a secondary prophylactic indication (SPI) had higher mean anxiety scores than patients with a primary prophylactic indication (PPI) at baseline, 3, and 12 months and higher mean depression scores at all-time points, except at 24 months. Women had higher mean anxiety scores as compared to men at all-time points; however, only higher mean depression scores at baseline. Overall, women with SPI had higher anxiety and depression symptom scores than men with SPI. Symptoms decreased over time in both women and men. From baseline to follow-up, the prevalence of anxiety (score ≥8) was highest in patients with SPI (13.3-20.2%) as compared to patients with PPI (range 10.0-14.7%). The prevalence of depression was stable over the follow-up period in both groups (range 8.5-11.1%).

CONCLUSION

Patients with a SPI reported higher anxiety and depression scores as compared to patients with PPI. Women reported higher anxiety scores than men, but only higher depression scores at baseline. Women with SPI reported the highest anxiety and depression scores overall.

Prognostic value of cardiovascular magnetic resonance left ventricular volumetry and geometry in patients receiving an implantable cardioverter defibrillator

BACKGROUND

Current indications for implantable cardioverter defibrillator (ICD) implantation for sudden cardiac death prevention rely primarily on left ventricular (LV) ejection fraction (LVEF). Currently, two different contouring methods by cardiovascular magnetic resonance (CMR) are used for LVEF calculation. We evaluated the comparative prognostic value of these two methods in the ICD population, and if measures of LV geometry added predictive value.

METHODS

In this retrospective, 2-center observational cohort study, patients underwent CMR prior to ICD implantation for primary or secondary prevention from January 2005 to December 2018. Two readers, blinded to all clinical and outcome data assessed CMR studies by: (a) including the LV trabeculae and papillary muscles (TPM) (trabeculated endocardial contours), and (b) excluding LV TPM (rounded endocardial contours) from the total LV mass for calculation of LVEF, LV volumes and mass. LV sphericity and sphere-volume indices were also calculated. The primary outcome was a composite of appropriate ICD shocks or death.

RESULTS

Of the 372 consecutive eligible patients, 129 patients (34.7%) had appropriate ICD shock, and 65 (17.5%) died over a median duration follow-up of 61 months (IQR 38-103). LVEF was higher when including TPM versus excluding TPM (36% vs. 31%, p < 0.001). The rate of appropriate ICD shock or all-cause death was higher among patients with lower LVEF both including and excluding TPM (p for trend = 0.019 and 0.004, respectively). In multivariable models adjusting for age, primary prevention, ischemic heart disease and late gadolinium enhancement, both LVEF (HR per 10% including TPM 0.814 [95%CI 0.688-0.962] p = 0.016, vs. HR per 10% excluding TPM 0.780 [95%CI 0.639-0.951] p = 0.014) and LV mass index (HR per 10 g/m2 including TPM 1.099 [95%CI 1.027-1.175] p = 0.006; HR per 10 g/m2 excluding TPM 1.126 [95%CI 1.032-1.228] p = 0.008) had independent prognostic value. Higher LV end-systolic volumes and LV sphericity were significantly associated with increased mortality but showed no added prognostic value.

CONCLUSION

Both CMR post-processing methods showed similar prognostic value and can be used for LVEF assessment. LVEF and indexed LV mass are independent predictors for appropriate ICD shocks and all-cause mortality in the ICD population.

Temporal trends and sex differences in sudden cardiac death in the Copenhagen City Heart Study

OBJECTIVE

More knowledge about the development of sudden cardiac death (SCD) in the general population is needed to develop meaningful predictors of SCD. Our aim with this study was to estimate the incidence of SCD in the general population and examine the temporal changes, demographics and clinical characteristics.

METHODS

All participants in the Copenhagen City Heart Study were followed from 1993 to 2016. All death certificates, autopsy reports and national registry data were used to identify all cases of SCD.

RESULTS

A total of 14 562 subjects were included in this study. There were 8394 deaths with all information available, whereof 1335 were categorised as SCD. The incidence of SCD decreased during the study period by 41% for persons aged 40-90 years, and the standardised incidence rates decreased from 504 per 100 000 person-years (95% CI 447 to 569) to 237 per 100 000 person-years (95% CI 195 to 289). The incidence rate ratio of SCD between men and women ≤75 years was 1.99 (95% CI 1.62 to 2.46). The proportion of SCD of all cardiac deaths decreased during the observation period and decreased with increasing age. Men had more cardiovascular comorbidities (OR 1.34, 95% CI 1.07 to 1.68, p<0. 01), and SCD was the first registered manifestation of cardiac disease in 50% of all cases.

CONCLUSION

The incidence of SCD in the general population has declined significantly during the study period but should be further investigated for more recent variations as well as novel risk predictors for persons with low to medium risk of SCD.

Faradization for insomnia: a sleep neurology history

NONE

Insomnia is highly prevalent and challenging to treat. We typically regard insomnia as a disorder of the modern world, but physicians and patients have been struggling with this malady for millennia. Here we present the curious historical practice of using electrization or faradization to treat insomnia. We present methods of application, hypotheses regarding mechanism of action, and historical case reports and case series to better understand this phenomenon. We put faradization for insomnia in the context of the modern use of electrical therapies to support and facilitate human health in multiple different health care arenas. Last, we examine current efforts to use these antiquated concepts to address insomnia through transcranial direct current stimulation and cranial electrical stimulation.

Changes in the Physical Function and Psychological Distress from Pre-Implant to 1, 6, and 12 Months Post-Implant in Patients Undergoing Implantable Cardioverter Defibrillator Therapy

Recipients of implantable cardioverter-defibrillator (ICD) therapy in Western countries often experience distressful physical and psychological adjustments. Sociocultural influences on post-implant recovery are likely; however, evidence from other ethnic/cultural backgrounds is lacking. This study aimed to examine the changes in physical function and psychological distress (anxiety and depressive symptoms) from pre-implant to one, six, and 12 months post-implant in Korean patients undergoing ICD therapy. A total of 34 patients underwent pre- to post-implant longitudinal assessments of physical and psychological function using mixed modeling procedures. Physical function significantly declined from pre-implant to one month post-implant (B = -10.05, p = 0.004) and then nearly returned to the pre-implant level at six months post-implant (B = 8.34, p = 0.028). This level of improvement continued through 12 months post-implant. In psychological distress, significant improvements were observed from pre-implant to one month (anxiety (B = -1.20, p = 0.020) and in depressive symptoms (B = -1.15, p = 0.037)), which then plateaued without significant changes from one to 12 months. We concluded that physical function recovery occurred six months post-implant, but function remained poor until 12 months post-implant. Psychological distress improved one month post-implant and it was maintained. Clinicians must provide more intensive interventions to improve long-term physical function after ICD therapy.

Utilization of implantable cardioverter-defibrillators for the prevention of sudden cardiac death in emerging countries: Improve SCA clinical trial

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are underutilized in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA Study is the largest prospective study to evaluate the benefit of ICD therapy in underrepresented geographies. This analysis reports the primary objective of the study.

OBJECTIVES

The objectives of this study was to determine whether patients with primary prevention (PP) indications with specific risk factors (1.5PP: syncope, nonsustained ventricular tachycardia, premature ventricular contractions >10/h, and low ventricular ejection fraction <25%) are at a similar risk of life-threatening arrhythmias as patients with secondary prevention (SP) indications and to evaluate all-cause mortality rates in 1.5PP patients with and without devices.

METHODS

A total of 3889 patients were included in the analysis to evaluate ventricular tachycardia or fibrillation therapy and mortality rates. Patients were stratified as SP (n = 1193) and patients with PP indications. The PP cohort was divided into 1.5PP patients (n = 1913) and those without any 1.5PP criteria (n = 783). The decision to undergo ICD implantation was left to the patient and/or physician. The Cox proportional hazards model was used to compute hazard ratios.

RESULTS

Patients had predominantly nonischemic cardiomyopathy. The rate of ventricular tachycardia or fibrillation in 1.5PP patients was not equivalent (within 30%) to that in patients with SP indications (hazard ratio 0.47; 95% confidence interval 0.38-0.57) but was higher than that in PP patients without any 1.5PP criteria (hazard ratio 0.67; 95% confidence interval 0.46-0.97) (P = .03). There was a 49% relative risk reduction in all-cause mortality in ICD implanted 1.5PP patients. In addition, the number needed to treat to save 1 life over 3 years was 10.0 in the 1.5PP cohort vs 40.0 in PP patients without any 1.5PP criteria.

CONCLUSION

These data corroborate the mortality benefit of ICD therapy and support extension to a selected PP population from underrepresented geographies.

Remote Monitoring of Implantable Cardioverter-Defibrillators, Cardiac Resynchronization Therapy and Permanent Pacemakers: A Health Technology Assessment

BACKGROUND

Under usual care, people with an implantable cardioverter-defibrillator (ICD), cardiac resynchronization therapy with or without a defibrillator (CRT-D and CRT-P, respectively), or a permanent pacemaker have follow-up in-person clinic visits. Remote monitoring of these devices allows the transfer of the information stored in the device so that it can be accessed by the clinic personnel via a secured website.

METHODS

We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for remote monitoring of ICDs, CRTs, and permanent pacemakers plus clinic visits compared with clinic visits alone. This is an update of a 2012 health technology assessment. In addition to the eligible randomized controlled trials (RCTs) from the 2012 publication, we included RCTs identified through a systematic literature search on June 1, 2017. We assessed the risk of bias of each study using the Cochrane risk of bias tool and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We conducted an economic evaluation to determine the cost-effectiveness of remote monitoring blended with in-clinic follow-up compared to in-clinic follow-up alone in patients with an ICD, a CRT-D, or a pacemaker. We determined the budget impact of blended remote monitoring in patients implanted with ICD, CRT-D, CRT-P, or pacemaker devices from the perspective of the Ontario Ministry of Health and Long-Term Care. To understand patient experiences with remote monitoring, we interviewed 16 patients and family members.

RESULTS

Based on 15 RCTs in patients with implanted ICDs or CRT-Ds, remote monitoring plus clinic visits resulted in fewer patients with inappropriate ICD shocks within 12 to 37 months of follow-up (moderate quality evidence; absolute risk difference -0.04 [95% confidence interval -0.07 to -0.01]), fewer total clinic visits (moderate quality evidence), and a shorter time to detection and treatment of events (moderate quality evidence) compared with clinic visits alone. There was a similar risk of major adverse events (moderate quality evidence).Based on 6 RCTs in patients with pacemakers, remote monitoring plus clinic visits reduced the arrhythmia burden (high quality evidence), the time to detection and treatment of arrhythmias (high quality evidence), and the number of clinic visits (moderate quality evidence]) compared with clinic visits alone. Here again, there was a similar risk of major adverse events (high quality evidence).Results from the economic evaluation showed that among ICD and CRT-D recipients, blended remote monitoring (remote monitoring plus in-clinic follow ups) was more costly (incremental value of $4,354 per person) and more effective, providing higher quality-adjusted life years (incremental value of 0.19), compared to in-clinic follow-up alone. Among pacemaker recipients, blended remote monitoring was less costly (with an incremental saving of $2,370 per person) and more effective (with an incremental value of 0.12 quality-adjusted life years) than with in-clinic follow-up alone. We estimated that publicly funding remote monitoring could result in cost savings of $14 million over the first five years.Participants using remote monitoring reported that these devices provide important medical and safety benefits in managing their heart condition. Remote cardiac monitoring provides patients and their family members with an increased freedom. Their belief that the device will help with earlier detection of technical or clinical problems reduces the amount of stress and distraction their condition causes in their lives.

CONCLUSIONS

Remote monitoring of ICDs, CRT-Ds, and pacemakers plus clinic visits resulted in improved outcomes without increasing the risk of major adverse events compared with clinic visits alone. Remote monitoring is a cost-effective option for patients implanted with cardiac electronic devices. Patients reported positive experiences using remote monitoring, and perceived that the device provided important medical and safety benefits.

Comparison of ventricular tachyarrhythmia recurrence between ischemic cardiomyopathy and dilated cardiomyopathy: a retrospective study

Background

The use of an implantable cardioverter-defibrillator (ICD) has been established as an effective secondary prevention strategy for ventricular tachycardia (VT)/ventricular fibrillation (VF). However, few reports discuss the difference in clinical predictors for recurrent VT/VF between patients with ischemic cardiomyopathy (ICM) and patients with dilated cardiomyopathy (DCM).

Methods

From May 2004 to December 2015, 132 consecutive patients who had ICM (n = 94) or DCM (n = 38) and had received ICD implantation for secondary prevention were enrolled in this study. All anti-tachycardia events during follow-up were validated. The clinical characteristics and echocardiographic parameters were obtained for comparison. The incidence of recurrence of VT/VF, cardiovascular mortality, all-cause mortality, the change of left ventricular ejection fraction (LVEF) and LV volume were analyzed.

Results

At a mean follow-up of 3.62 ± 2.93 years, 34 patients (36.2%) in the ICM group and 22 patients (57.9%) in the DCM group had a recurrence of VT/VF episodes (p = 0.032). The DCM group had a lower LVEF (p = 0.019), a larger LV end-diastolic volume (LVEDV) (p = 0.001), a higher prevalence of LVEDV >158 mL (p = 0.010), and a larger LV end-systolic volume (p = 0.010) than the ICM group. LVEDV >158 mL and no use of angiotensin-converting-enzyme inhibitor/angiotensin receptor blocker were independent predictors of recurrences of VT/VF in ICM patients but not in DCM patients. There were no difference in cardiovascular mortality and all-cause mortality between the ICM and DCM patients.

Conclusion

The DCM patients had a higher recurrence rate of VT/VF than did the ICM patients during long-term follow-up. An enlarged LV is an independent predictor of the recurrence of VT/VF in ICM patients receiving ICD for secondary prevention.

Effectiveness of a comprehensive interactive eHealth intervention on patient-reported and clinical outcomes in patients with an implantable cardioverter defibrillator [ACQUIRE-ICD trial]: study protocol of a national Danish randomised controlled trial

BACKGROUND

In Denmark and other countries, there has been a shift in the management of patients with an implantable cardioverter defibrillator (ICD) with remote device monitoring largely replacing in-hospital visits. Less patient-nurse and patient-physician interaction may lead to gaps in patients' quality of care and impede patients' adaptation to living successfully with the ICD. A comprehensive eHealth intervention that include goal-setting, monitoring of symptoms of depression, anxiety, and quality of life, psychological treatment, information provision, supportive tools, online dialogues with nursing staff and access to an online community network, may help fill these gaps and be particularly beneficial to patients who suffer from anxiety and depression. This study will evaluate the effectiveness of the ACQUIRE-ICD care innovation, a comprehensive and interactive eHealth intervention, on patient-reported and clinical outcomes.

METHODS

The ACQUIRE-ICD study is a multicenter, prospective, two-arm, unblinded randomised controlled superiority trial that will enroll 478 patients implanted with a first-time ICD or ICD with cardiac synchronisation therapy (CRT-D) from the six implanting centers in Denmark. The trial will evaluate the clinical effectiveness and cost-effectiveness of the ACQUIRE-ICD care innovation, as add-on to usual care compared with usual care alone. The primary endpoint, device acceptance, assessed with the Florida Patient Acceptance Survey, is evaluated at 12 months' post implant. Secondary endpoints, evaluated at 12 and 24 months' post implant, include patient-reported outcomes, return to work, time to first ICD therapy and first hospitalisation, mortality and cost-effectiveness.

DISCUSSION

The effectiveness of a comprehensive and interactive eHealth intervention that relies on patient-centred and personalised tools offered via a web-based platform targeted to patients with an ICD has not been assessed so far. The ACQUIRE-ICD care innovation promotes and facilitates that patients become active participants in the management of their disease, and as such addresses the need for a more patient-centered disease-management approach. If the care innovation proves to be beneficial to patients, it may not only increase patient empowerment and quality of life but also free up time for clinicians to care for more patients.

TRIAL REGISTRATION

The trial has been registered on https://clinicaltrials.gov/ct2/show/NCT02976961 on November 30, 2016 with registration number [ NCT02976961 ].

Selection bias, interventions and outcomes for survivors of cardiac arrest

OBJECTIVE

Cardiac catheterisation and implantable cardioverter defibrillator (ICD) insertion are increasingly common following cardiac arrest survival. However, much of the evidence for the benefit is observational, leaving open the possibility that biased patient selection confounds the association between these invasive procedures and improved outcome. We evaluated the likelihood of selection bias in the association between cardiac catheterisation or ICD placement and outcome by measuring long-term outcomes overall and in a cause-specific approach that separated cardiac mortality from non-cardiac mortality.

METHODS

We performed a multivariable survival analysis of a clinical cohort between 2005 and 2013, with follow-up through 2015. We included patients who had out-of-hospital or inhospital cardiac arrest that survived to discharge, and evaluated the association between cardiac catheterisation or ICD insertion and all-cause, cardiovascular and non-cardiovascular mortality.

RESULTS

Among 678 patients who survived cardiac arrest, we observed lower all-cause mortality among patients who underwent cardiac catheterisation (adjusted HR (aHR) 0.40; P<0.01) or ICD insertion (aHR 0.55; P<0.01). However, cause-specific analysis showed that the benefits of cardiac catheterisation and ICD insertion resulted from reduced non-cardiac causes of death (cardiac catheterisation: aHR 0.24, P<0.01; ICD: aHR 0.58, P<0.01), while reduced cardiac cause of death was not associated with cardiac catheterisation (cardiac catheterisation: aHR 0.75, P=0.33).

CONCLUSIONS

There is evidence of selection bias in the secondary prevention survival benefit attributable to cardiac catheterisation for patients who survive cardiac arrest. Observational studies that consider its effects on all-cause mortality likely overestimate the potential benefit of this procedure.