The National ICD Registry Report: Version 2.1 including leads and pediatrics for years 2010 and 2011

MR-Safe Cartesian Platform for Active Cardiac Shimming: Preliminary Validation

OBJECTIVE

Implanted Cardioverter Defibrillators (ICDs) induce a large (100 parts per million) inhomogeneous magnetic field in the magnetic resonance imaging (MRI) scanner which cannot be corrected by the scanner's built-in shim coils, leading to significant image artifacts that can make portions of the heart unreadable. To compensate for the field inhomogeneity, an active shim coil capable of countering the field deviation in user-defined regions was designed that must be optimally placed at patient-specific locations. We aim to develop and evaluate an MR-safe robotic solution for automated shim coil positioning.

METHODS

We designed and fabricated an MR-safe Cartesian platform that holds the shim coil inside the scanner. The platform consists of three lead screw stages actuated by pneumatic motors, achieving decoupled translations of 140 mm in each direction. The platform is made of plastics and fiberglass with the control electronics placed outside the scanner room, ensuring MR safety. Mechanical modeling was derived to provide design specifications.

RESULTS

Experiments show that the platform achieves less than 2 mm average motion error and 0.5 mm repeatability in all directions, and reduces the adjustment time from 5 min to a few seconds. Phantom and animal trials were conducted, showing that the proposed system is able to position a heavy shim coil ( kg) for improved ICD artifact suppression.

CONCLUSION

This robotic platform provides an effective method for reliable shim coil positioning inside the scanner.

SIGNIFICANCE

This work contributes to improving cardiac MRI quality that could facilitate accurate diagnosis and treatment planning for patients with implanted ICDs.

Aligning goals with care: Advance directives in older adults with implantable cardioverter-defibrillators

BACKGROUND

Patients ≥80 with implantable cardioverter-defibrillators (ICDs) have high rates of hospitalization and mortality, yet few have documented advance directives. We sought to determine the prevalence of advance directives in adults ≥80 years with ICDs, focusing on those with frailty and cognitive impairment.

METHODS

Prospective cohort study (July 2016-May 2019) in an electrophysiology clinic. Presence of advance directives (health care proxies [HCP] and living wills [LW], or medical orders for life-sustaining treatment [MOLST]) was determined by medical record review. Frailty and cognitive impairment were screened using 4-m gait speed and Mini-Cog.

RESULTS

77 Veterans were evaluated. Mean age 84 years, 100% male, 70% frail. Overall, 52 (68%) had an HCP and 37 (48%) had a LW/MOLST. Of 67 with cognitive testing, 36% were impaired. HCP documentation was similar among frail and non-frail (69% vs. 65%). LW/MOLST was more prevalent among frail versus non-frail (52% vs. 39%). There was no difference in HCP documentation by cognitive status (67%). A LW/MOLST was more frequent for cognitively impaired versus non-impaired (50% vs. 42%). Among 19 Veterans who were frail and cognitively impaired, 14 (74%) had an HCP and 11 (58%) had a LW/MOLST.

CONCLUSIONS

Most Veterans had a documented advance directive, but a significant minority did not. Simple frailty and cognitive screening tools can rapidly identify patients for whom discussion of advance directives is especially important.

Frailty Status Modifies the Efficacy of ICD Therapy for Primary Prevention Among Patients With HF

BACKGROUND

Implantable cardioverter-defibrillator (ICD) therapy is recommended to reduce mortality risk in patients with heart failure with reduced ejection fraction (HFrEF). Frailty is common among patients with HFrEF and is associated with increased mortality risk. Whether the therapeutic efficacy of ICD is consistent among frail and nonfrail patients with HFrEF remains unclear.

OBJECTIVES

The aim of this study was to evaluate the effect modification of baseline frailty burden on ICD efficacy for primary prevention among participants of the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial).

METHODS

Participants in SCD-HeFT with HFrEF randomized to ICD vs placebo were included. Baseline frailty was estimated using the Rockwood Frailty Index (FI), and participants were stratified into high (FI > median) vs low (FI ≤ median) frailty burden groups. Multivariable Cox models with multiplicative interaction terms (frailty × treatment arm) were constructed to evaluate whether baseline frailty status modified the treatment effect of ICD for all-cause mortality.

RESULTS

The study included 1,676 participants (mean age: 59 ± 12 years, 23% women) with a median FI of 0.30 (IQR: 0.23-0.37) in the low frailty group and 0.54 (IQR: 0.47-0.60) in the high frailty group. In adjusted Cox models, baseline frailty status significantly modified the treatment effect of ICD therapy (Pinteraction = 0.047). In separate stratified analysis by frailty status, ICD therapy was associated with a lower risk of all-cause mortality among participants with low frailty burden (HR: 0.56; 95% CI: 0.40-0.78) but not among those with high frailty burden (HR: 0.86; 95% CI: 0.68-1.09).

CONCLUSIONS

Baseline frailty modified the efficacy of ICD therapy with a significant mortality benefit observed among participants with HFrEF and a low frailty burden but not among those with a high frailty burden.

Appropriateness of implantable cardioverter-defibrillator device implants in the United States

BACKGROUND

The appropriate use criteria (AUCs) are a diverse group of indications aimed to better evaluate the benefits of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy.

OBJECTIVE

The purpose of this study was to quantify the proportion of ICD and cardiac resynchronization therapy with defibrillator (CRT-D) implants as appropriate, may be appropriate (MA), or rarely appropriate (RA) on the basis of the AUC guidelines.

METHODS

This is a multicenter retrospective study of patients within the National Cardiovascular Data Registry undergoing ICD implantation between April 2018 and March 2019 at >1500 US hospitals. The appropriateness of ICD implants was adjudicated using the AUC.

RESULTS

Of 309,318 ICDs, 241,438 were primary prevention implants (78.1%) and 67,880 secondary prevention implants (21.9%); 243,532 (79%) were mappable to the AUC. For primary prevention, 185,431 ICDs (96.4%) were appropriate, 5660 (2.9%) MA, and 1205 (0.6%) RA. For secondary prevention, 47,498 ICDs (92.7%) were appropriate, 2581 (5%) MA, and 1157 (2.3%) RA. A significant number of RA devices were implanted in patients with New York Heart Association class IV heart failure who were ineligible for advanced therapies (53.9%) and those with myocardial infarction within 40 days (18.1%). The appropriateness of the pacing lead was more variable, with 48,470 dual-chamber ICD implants (62%) being classified as appropriate, 29,209 (37.4%) MA, and 448 (0.6%) RA. Among CRT-D implants, 63,848 (82.2%) were appropriate, 9900 (12.7%) MA, and 3940 (5.1%) RA for left ventricular pacing. A total of 99,754 implants were deemed appropriate but excluded from Centers for Medicare & Medicaid Services National Coverage Determination. More than 92% of hospitals had an RA implant rate of <4%.

CONCLUSION

In this large national registry, 95% of mappable ICD and CRT-D implants were considered appropriate, with <2% of RA implants. Nearly 100,000 appropriate implants are excluded by Centers for Medicare & Medicaid Services National Coverage Determination.

Left ventricular lead implantation failure in an unselected nationwide cohort

BACKGROUND

Left ventricular (LV) lead implantation is often the most challenging aspect of cardiac resynchronization therapy (CRT) procedures; early studies reported implant failure rates in ∼10% of cases.

OBJECTIVE

The purpose of this study was to define rates, reasons for, and factors independently associated with LV lead implant failure.

METHODS

We studied patients with left bundle branch block and ejection fraction ≤ 35% who underwent planned de novo transvenous CRT implantation (2010-2016) and were reported to the National Cardiovascular Data Registry ICD Registry. Independent predictors of LV lead implant failure were determined using logistic regression; age, sex, and variables with a univariable P value of <.15 were considered for inclusion in the model.

RESULTS

Of the 111,802 patients who underwent a planned CRT procedure, 3.6% of patients (n = 3979) had LV lead implant failure. Reasons for implant failure included venous access (7.5%), coronary sinus access (64.3%), tributary vein access (13.5%), coronary sinus dissection (7.6%), unacceptable threshold (4.4%), and diaphragmatic stimulation (1.7%). Significant independent predictors of LV lead implant failure included younger age (odds ratio [OR] 1.01; 95% confidence interval [CI] 0.1.01-1.02), female sex (OR 1.38; 95% CI 1.29-1.47), black race (vs white, OR 1.44; 95% CI 1.32-1.57), Hispanic ethnicity (OR 1.23; 95% CI 1.08-1.40), QRS duration (OR 1.055 per 10 ms; 95% CI 1.038-1.072 per 10 ms), obstructive sleep apnea (OR 1.14; 95% CI 1.04-1.24), and implantation by a physician without specialized training (vs electrophysiology trained, OR 1.53; 95% CI 1.34-1.76).

CONCLUSION

LV lead implant failure is uncommon in the current era and is most commonly due to coronary sinus access failure. Predictors of LV lead implant failure included younger age, female sex, black race, Hispanic ethnicity, increased QRS duration, sleep apnea, and absence of electrophysiology training.

Impact of age on the prognosis of patients with ventricular tachyarrhythmias and aborted cardiac arrest

BACKGROUND

This study evaluated the prognostic impact of age on patients presenting with ventricular tachyarrhythmias (VTA) and aborted cardiac arrest.

MATERIAL AND METHODS

The present registry-based, monocentric cohort study included all consecutive patients presenting at the University Medical Center Mannheim (UMM) between 2002 and 2016 with ventricular tachycardia (VT), ventricular fibrillation (VF) and aborted cardiac arrest. Middle-aged (40-60 years old) were compared to older patients (> 60 years old). Furthermore, age was analyzed as a continuous variable. The primary endpoint was all-cause mortality at 2.5 years. The secondary endpoints were cardiac death at 24 h, all-cause mortality at index hospitalization, all-cause mortality after index hospitalization and the composite endpoint at 2.5 years of cardiac death at 24 h, recurrent VTA, and appropriate implantable cardioverter defibrillator (ICD) treatment.

RESULTS

A total of 2259 consecutive patients were included (28% middle-aged, 72% older). Older patients were more often associated with all-cause mortality at 2.5 years (27% vs. 50%; hazard ratio, HR = 2.137; 95% confidence interval, CI 1.809-2.523, p = 0.001) and the secondary endpoints. Even patient age as a continuous variable was independently associated with mortality at 2.5 years in all types of VTA. Adverse prognosis in older patients was demonstrated by multivariate Cox regression analyses and propensity score matching. Chronic kidney disease (CKD), systolic left ventricular dysfunction (LVEF) < 35%, cardiopulmonary resuscitation (CPR) and cardiogenic shock worsened the prognosis for both age groups, whereas acute myocardial infarction (STEMI/NSTEMI) and the presence of an ICD improved prognosis.

CONCLUSION

The results of this study suggest that increasing age is associated with increased mortality in VTA patients. Compared to the middle-aged, older patients were associated with higher all-cause mortality at 2.5 years and the secondary endpoints.

End-Stage/Advanced Heart Failure: Geriatric Palliative Care Considerations

Heart failure remains a condition with high morbidity and mortality affecting 23 million people globally with a cost burden equivalent to 5.4% of the total health care budget in the United States. These costs include repeated hospitalizations as the disease advances and care that may not align with individual wishes and values. The coincidence of comorbid conditions with advanced heart failure poses significant challenges in the geriatric population. Advance care planning, medication education, and minimizing polypharmacy are primary palliative opportunities leading to specialist palliative care such as symptom management at end of life and timing of referral to hospice.

Inter-American Society of Cardiology (CIFACAH-ELECTROSIAC) and Latin-American Heart Rhythm Society (LAHRS): multidisciplinary review on the appropriate use of implantable cardiodefibrillator in heart failure with reduced ejection fraction

BACKGROUND

Our main objective was to present a multidisciplinary review on the epidemiology of sudden cardiac death (SCD) and the tools that could be used to identify malignant ventricular arrhythmias (VAs) and to perform risk stratification. In addition, indications and contraindications for the use of implantable cardioverter defibrillator (ICD) in general and in special populations including the elderly and patients with chronic kidney disease (CKD) are also given.

METHODS

An expert group from the Inter American Society of Cardiology (IASC), through their HF Council (CIFACAH) and Electrocardiology Council (ElectroSIAC), together with the Latin American Heart Rhythm Society (LAHRS), reviewed and discussed the literature regarding the appropriate use of an ICD in people with heart failure (HF) with reduced ejection fraction (HFpEF). Indications and contraindications for the use of ICD are presented in this multidisciplinary review.

RESULTS

Numerous clinical studies have demonstrated the usefulness of ICD in both primary and secondary prevention of SCD in HFpEF. There are currently precise indications and contraindications for the use of these devices.

CONCLUSIONS

In some Latin American countries, a low rate of implantation is correlated with low incomes, but this is not the case for all Latin America. Determinants of the low rates of ICD implantation in many Latin American countries are still a matter of research. VA remains one of the most common causes of cardiovascular death associated with HFrEF and different tools are available for stratifying the risk of SCD in this population.

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.

Economic Evaluation of Anesthesiology-Led Cardiac Implantable Electronic Device Service

BACKGROUND

Implementation of an anesthesiology-led cardiac implantable electronic device (CIED) service can be viewed to have economic and efficiency challenges. This study evaluates the cost savings of an anesthesiology-led CIED service.

METHODS

A total of 830 patients presented in the pre-implementation period from 1 March 2016 to 31 December 2017, and 1981 patients presented in the post-implementation period from 1 January 2018 to 31 October 2021. Interrupted time-series analysis for single-group comparisons was used to evaluate the cost savings resulting from reduction in operating room (OR) start delays for patients with CIEDs.

RESULTS

OR start-time delay was reduced by 10.6 min (95%CI: -20.5 to -0.83), comparing pre- to post-implementation. For an OR cost of USD 45/min, we estimated the direct cost to the department to be USD 1.68/min. The intervention translated into a total cost reduction during the intervention period of USD 250,000 (USD 18,000 to USD 470,000) per year for the institution and USD 9800 (USD 730 to USD 17,000) per year for the department. The yearly cost of employing a full-time team of CIED specialists would have been USD 135,456. The service triggered electrophysiology consultation on 13 device malfunctions.

CONCLUSIONS

An anesthesiology-led CIED service resulted in substantial cost savings, increased OR efficiency and patient safety.

Risk of ventricular arrhythmias following implantable cardioverter-defibrillator generator change in patients with recovered ejection fraction: Implications for shared decision-making

INTRODUCTION

Guidelines indicate primary-prevention implantable cardioverter-defibrillators (ICDs) for most patients with left ventricular ejection fraction (LVEF) ≤ 35%. Some patients' LVEFs improve during the life of their first ICD. In patients with recovered LVEF who never received appropriate ICD therapy, the utility of generator replacement upon battery depletion remains unclear. Here, we evaluate ICD therapy based on LVEF at the time of generator change, to educate shared decision-making regarding whether to replace the depleted ICD.

METHODS

We followed patients with a primary-prevention ICD who underwent generator change. Patients who received appropriate ICD therapy for ventricular tachycardia or ventricular fibrillation (VT/VF) before generator change were excluded. The primary endpoint was appropriate ICD therapy, adjusted for the competing risk of death.

RESULTS

Among 951 generator changes, 423 met inclusion criteria. During 3.4 ± 2.2 years follow-up, 78 (18%) received appropriate therapy for VT/VF. Compared to patients with recovered LVEF > 35% (n = 161 [38%]), those with LVEF ≤ 35% (n = 262 [62%]) were more likely to require ICD therapy (p = .002; Fine-Gray adjusted 5-year event rates: 12.7% vs. 25.0%). Receiver operating characteristic analysis revealed the optimal LVEF cutoff for VT/VF prediction to be 45%, the use of which further improved risk stratification (p < .001), with Fine-Gray adjusted 5-year rates 6.2% versus 25.1%.

CONCLUSION

Following ICD generator change, patients with primary-prevention ICDs and recovered LVEF have significantly lower risk of subsequent ventricular arrhythmias compared to those with persistent LVEF depression. Risk stratification at LVEF 45% offers significant additional negative predictive value over a 35% cutoff, without a significant loss in sensitivity. These data may be useful during shared decision-making at the time of ICD generator battery depletion.

Benefits, harms, and costs of newborn genetic screening for hypertrophic cardiomyopathy: Estimates from the PreEMPT model

PURPOSE

Population newborn genetic screening for hypertrophic cardiomyopathy (HCM) is feasible, however its benefits, harms, and cost-effectiveness are uncertain.

METHODS

We developed a microsimulation model to simulate a US birth cohort of 3.7 million newborns. Those identified with pathogenic/likely pathogenic variants associated with increased risk of HCM underwent surveillance and recommended treatment, whereas in usual care, individuals with family histories of HCM underwent surveillance.

RESULTS

In a cohort of 3.7 million newborns, newborn genetic screening would reduce HCM-related deaths through age 20 years by 44 (95% uncertainty interval [UI] = 10-103) however increase the numbers of children undergoing surveillance by 8127 (95% UI = 6308-9664). Compared with usual care, newborn genetic screening costs $267,000 per life year saved (95% UI, $106,000 to $919,000 per life year saved).

CONCLUSION

Newborn genetic screening for HCM could prevent deaths but at a high cost and would require many healthy children to undergo surveillance. This study shows how modeling can provide insights into the tradeoffs between benefits and costs that will need to be considered as newborn genetic screening is more widely adopted.

Inappropriate Shocks With Subcutaneous Implantable Cardioverter-Defibrillator in a Young Patient: A Case Report

Implantable cardioverter-defibrillators (ICDs) are increasingly used for the primary and secondary prevention of sudden cardiac death (SCD). Currently, transvenous (TV) and subcutaneous (S) ICDs are the two different types used. Preservation of central venous vasculature, no risk of vascular or myocardial injury during implant, easier explantation, and lower risk of systemic infections have driven the increased use of S-ICDs. The shocks delivered by ICDs for non-life-threatening arrhythmias or because of oversensing T waves or noise are known as inappropriate shocks. Here, we present the case of a 33-year-old man who had an S-ICD implanted in 2019 for hypertrophic cardiomyopathy. He had a TV-ICD implanted in 2010 which was explanted in 2013 due to infective endocarditis, and the patient underwent a mechanical mitral valve replacement. He was at intermediate risk for SCD over the next five years. He had an S-ICD implanted in 2019 and had never received any shock before. Electrocardiogram showed normal sinus rhythm, left axis deviation, QRS 110 ms, hyperacute T waves in inferior leads, and T-wave inversion in lateral leads. He then began experiencing inappropriate shocks three years after S-ICD placement due to a drop in R wave amplitude secondary to noise oversensing in October 2022. Despite reprogramming the device from the primary vector to an alternate vector, the patient had further inappropriate shocks two months later due to noise oversensing. The patient was discussed in a multidisciplinary team meeting and the S-ICD was explanted according to the patient's wishes and a loop recorder was implanted.

Age and the Risk of Ventricular Tachyarrhythmia in Patients With an Implantable Cardioverter-Defibrillator

BACKGROUND

The benefit of implantable cardioverter-defibrillators (ICDs) in elderly patients is controversial.

OBJECTIVES

The aims of this study were to evaluate the risk for ventricular tachyarrhythmia (VTA) and ICD shocks by age groups and to assess the competing risk for VTA and death without prior VTA.

METHODS

The study included 5,170 primary prevention ICD recipients enrolled in 5 landmark ICD trials (MADIT [Multicenter Automatic Defibrillator Implantation Trial] II, MADIT-Risk, MADIT-CRT [MADIT Cardiac Resynchronization Therapy], MADIT-RIT [MADIT Reduce Inappropriate Therapy], and RAID [Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillator]). Fine and Gray regression analysis was used to evaluate the risk for fast VTA (ventricular tachycardia ≥200 beats/min or ventricular fibrillation) vs death without prior fast VTA in 3 prespecified age groups: <65, 65 to <75, and ≥75 years.

RESULTS

The cumulative incidence of fast VTA at 3 years was similar for patients <65 years of age and those 65 to <75 years of age (17% vs 15%) and was lowest among patients ≥75 years of age (10%) (P < 0.001). Multivariate Fine and Gray analysis showed a 40% lower risk for fast VTA in patients ≥75 years of age (HR: 0.60; 95% CI: 0.46-0.78; P < 0.001) compared with patients <65 years of age. In patients ≥75 years of age, a risk reversal was observed whereby the risk for death without prior fast VTA exceeded the risk for developing fast VTA. A history of nonsustained ventricular tachycardia, male sex, and the presence of nonischemic cardiomyopathy were identified as predictors of fast VTA in patients ≥75 years of age.

CONCLUSIONS

Patients ≥75 years of age have a significantly lower risk for VTA and ICD shocks compared with younger patients. Aging is associated with a higher risk for death compared with the risk for fast VTA, the reverse of what is seen in younger patients.

Survival Probability and Survival Benefit Associated With Primary Prevention Implantable Cardioverter-Defibrillator Generator Changes

Background As patients derive variable benefit from generator changes (GCs) of implantable cardioverter-defibrillators (ICDs) with an original primary prevention (PP) indication, better predictors of outcomes are needed. Methods and Results In the National Cardiovascular Data Registry ICD Registry, patients undergoing GCs of initial non-cardiac resynchronization therapy PP ICDs in 2012 to 2016, predictors of post-GC survival and survival benefit versus control heart failure patients without ICDs were assessed. These included predicted annual mortality based on the Seattle Heart Failure Model, left ventricular ejection fraction (LVEF) >35%, and the probability that a patient's death would be arrhythmic (proportional risk of arrhythmic death [PRAD]). In 40 933 patients undergoing GCs of initial noncardiac resynchronization therapy PP ICDs (age 67.7±12.0 years, 24.5% women, 34.1% with LVEF >35%), Seattle Heart Failure Model-predicted annual mortality had the greatest effect size for decreased post-GC survival (P<0.0001). Patients undergoing GCs of initial noncardiac resynchronization therapy PP ICDs with LVEF >35% had a lower Seattle Heart Failure Model-adjusted survival versus 23 472 control heart failure patients without ICDs (model interaction hazard ratio, 1.21 [95% CI, 1.11-1.31]). In patients undergoing GCs of initial noncardiac resynchonization therapy PP ICDs with LVEF ≤35%, the model indicated worse survival versus controls in the 21% of patients with a PRAD <43% and improved survival in the 10% with PRAD >65%. The association of the PRAD with survival benefit or harm was similar in patients with or without pre-GC ICD therapies. Conclusions Patients who received replacement of an ICD originally implanted for primary prevention and had at the time of GC either LVEF >35% alone or both LVEF ≤35% and PRAD <43% had worse survival versus controls without ICDs.

Trends in Use of Single- vs Dual-Chamber Implantable Cardioverter-Defibrillators Among Patients Without a Pacing Indication, 2010-2018

IMPORTANCE

Use of dual-chamber implantable cardioverter-defibrillator (ICD) systems among patients without a pacing indication is an example of low-value care given higher procedural risks, higher costs, and little evidence for benefit from an atrial lead. However, variation in the use of dual-chamber systems was present among patients without a pacing indication.

OBJECTIVE

To examine the temporal trends and hospital variation in use of single- and dual-chamber ICD implantation among patients without a pacing indication undergoing first-time ICD implantation.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter cross-sectional study was conducted using the US National Cardiovascular Data Registry ICD Registry. A total of 266 182 patients undergoing initial implantation of a single- or dual-chamber transvenous ICD without a bradycardia pacing indication, class I or II cardiac resynchronization therapy indication, or history of atrial fibrillation or atrial flutter were included. The study was conducted from April 1, 2010, to December 31, 2018; data analysis was performed from October 19, 2020, to January 5, 2022.

EXPOSURES

Implantation of a single- or dual-chamber ICD.

MAIN OUTCOMES AND MEASURES

Temporal trends among patients undergoing single- vs dual-chamber ICDs were determined using the Cochran-Armitage trend test, and hospital-level variation using adjusted hospital median odds ratios was examined.

RESULTS

A total of 266 182 patients (single-chamber ICD, 134 925; dual-chamber ICD, 131 257) were included in this analysis; mean (SD) age was 58.0 (14.0) years and 91 990 patients (68.2%) were men. The use of dual-chamber ICDs decreased from 64.7% (n = 15 694) in 2010 to 42.2% (n = 9762) in 2018 (P < .001). Adjusted for patient characteristics, the median hospital-level proportion of single-chamber ICDs increased from 42.9% (95% CI, 42.6%-45.0%) in 2010 to 50.0% (95% CI, 47.8%-51.0%) in 2018. The median odds ratio for the use of dual-chamber ICDs, adjusted for patient characteristics, was 1.6 (95% CI, 1.6-1.8) in 2010 and 1.5 (95% CI, 1.5-1.8) in 2018, indicating decreasing but persistent variation in use.

CONCLUSIONS AND RELEVANCE

In this national study of US patients undergoing first-time ICD implantation without a clinical indication for an atrial lead, the use of dual-chamber devices decreased. However, institutional variability in the use of atrial leads persists, suggesting differences in individual or institutional cultures of real-world practice and opportunity to reduce this low-value practice.

Informed consent and compulsory medical device registries: ethics and opportunities

Many high-risk medical devices earn US marketing approval based on limited premarket clinical evaluation that leaves important questions unanswered. Rigorous postmarket surveillance includes registries that actively collect and maintain information defined by individual patient exposures to particular devices. Several prominent registries for cardiovascular devices require enrolment as a condition of reimbursement for the implant procedure, without informed consent. In this article, we focus on whether these registries, separate from their legal requirements, have an ethical obligation to obtain informed consent from enrolees, what is lost in not doing so, and the ways in which seeking and obtaining consent might strengthen postmarket surveillance in the USA.

Fragmented QRS is associated with ventricular arrhythmias in heart failure patients: A systematic review and meta-analysis

INTRODUCTION

Many primary prevention heart failure (HF) patients with an implantable cardiac defibrillator (ICD) rarely experience life-threatening ventricular arrhythmias (VA). New strategies are required to identify patients most at risk of VA and sudden cardiac death who would benefit from an ICD. One potential method is the detection of fragmented QRS (fQRS) on the electrocardiogram. The aim was to assess the predictive capacity of fQRS for VA and mortality in ischemic (ICM) and non-ischemic cardiomyopathy (NICM) primary prevention HF patients.

METHODS AND RESULTS

A systematic review and meta-analysis of studies examining fQRS in HF patients with or without an ICD who met primary prevention indications with reduced ejection fraction ≤40%. Outcome measures were VA (or appropriate ICD therapy) and all-cause mortality. Ten studies involving 3885 patients were included for analysis. Most patients were male with non-fQRS patients being significantly younger (-1.5[-2.66, -0.42], p = .03). Diabetes was more likely in fQRS patients (1.12[1.01, 1.25], p = .03) while non-fQRS patients were 28% more likely to have a history of atrial fibrillation (0.82[0.67,1.00], p = .05). Ventricular arrhythmias were significantly 1.5 times more likely in patients with fQRS (1.51[1.02, 2.25], p = .04). HF patients were 1.7 times more likely to die of any cause if fQRS was present (1.68[1.13, 2.52], p = .01). NICM patients with fQRS have a significant 2.6-fold increased incidence of death compared with ICM patients (2.55[1.63, 3.98], p < .0001).

CONCLUSION

fQRS is associated with VA and all-cause mortality and may be a novel marker in the risk stratification of primary prevention HF patients indicated for ICD implantation.

Longitudinal Outcomes Associated With Non-Evidence-Based Implantable Cardioverter-Defibrillators Among Medicare Beneficiaries (From the National Cardiovascular Data Registry)

Primary prevention implantable cardioverter-defibrillators (ICDs) in patients with recent myocardial infarction or coronary revascularization and those with newly diagnosed or severe heart failure (HF) are considered non-evidence-based, as defined by pivotal randomized clinical trials. Although non-evidence-based ICDs have been associated previously with greater risk of in-hospital adverse events, longitudinal outcomes are not known. We used Medicare-linked data from the National Cardiovascular Data Registry's ICD Registry to identify patients discharged alive following first-time primary prevention ICD implantations performed between 2010 and 2013. We compared longitudinal outcomes, including all-cause mortality and all-cause hospital readmission among patients receiving non-evidence-based versus evidence-based ICDs, up to 4.75 years after implantation, using multivariable time-to-event analyses. Of 71,666 ICD implantations, 9,609 (13.4%) were classified as non-evidence-based. Compared to patients receiving evidence-based ICDs, non-evidence-based ICD recipients had greater mortality risk at 90 days (HR = 1.44, CI: 1.37 - 1.52, p <0.0001) and at 1 year (HR = 1.19, CI: 1.15 - 1.24, p <0.0001), but similar mortality risk at 3 years (HR = 1.03, CI: 0.98 - 1.08, p = 0.2630). Risk of all-cause hospitalization was higher in patients with non-evidence-based ICDs at 90 days (HR = 1.17, CI: 1.14 - 1.20, p <0.0001), but the difference diminished at 1 year (HR = 1.04, CI 1.00 - 1.07, p = 0.0272) and at 3 years (HR = 0.94, CI: 0.90 - 0.99, p = 0.0105). In conclusion, among patients undergoing primary prevention ICD implantations between 2010 and 2013, those with non-evidence-based ICDs were at increased risk of mortality and readmission during longitudinal follow-up. Differences in the risk of mortality and hospitalization were highest in the first year following device implantation.

Cost-minimization analysis of a wearable cardioverter defibrillator in adult patients undergoing ICD explant procedures: Clinical and economic implications

Aims

Patients with permanently increased risk of sudden cardiac death (SCD) can be protected by implantable cardioverter defibrillators (ICD). If an ICD must be removed due to infection, for example, immediate reimplantation might not be possible or indicated. The wearable cardioverter defibrillator (WCD) is an established, safe and effective solution to protect patients from SCD during this high‐risk bridging period. Very few economic evaluations on WCD use are currently available.

Methods

We conducted a systematic review to evaluate the available evidence of WCD in patients undergoing ICD explant/lead extraction. Additionally, a decision model was developed to compare use and costs of the WCD with standard therapy (in‐hospital stay). For this purpose, a cost‐minimization analysis was conducted, and complemented by a one‐way sensitivity analysis.

Results

In the base case scenario, the WCD was less expensive compared to standard therapy. The cost‐minimization analysis showed a cost reduction of €1782 per patient using the WCD. If costs of standard care were changed, cost savings associated with the WCD varied from €3500 to €0, assuming costs for standard care of €6800 to €3600.

Conclusion

After ICD explantation, patients can be safely and effectively protected from SCD after hospital discharge through WCD utilization. Furthermore, the use of a WCD for this patient group is cost saving when compared to standard therapy.

Cardiac Magnetic Resonance Assessment of Response to Cardiac Resynchronization Therapy and Programming Strategies

OBJECTIVES

The objective was to determine the feasibility and effectiveness of cardiac magnetic resonance (CMR) cine and strain imaging before and after cardiac resynchronization therapy (CRT) for assessment of response and the optimal resynchronization pacing strategy.

BACKGROUND

CMR with cardiac implantable electronic devices can safely provide high-quality right ventricular/left ventricular (LV) ejection fraction (RVEF/LVEF) assessments and strain.

METHODS

CMR with cine imaging, displacement encoding with stimulated echoes for the circumferential uniformity ratio estimate with singular value decomposition (CURE-SVD) dyssynchrony parameter, and scar assessment was performed before and after CRT. Whereas the pre-CRT scan constituted a single "imaging set" with complete volumetric, strain, and scar imaging, multiple imaging sets with complete strain and volumetric data were obtained during the post-CRT scan for biventricular pacing (BIVP), LV pacing (LVP), and asynchronous atrial pacing modes by reprogramming the device outside the scanner between imaging sets.

RESULTS

100 CMRs with a total of 162 imaging sets were performed in 50 patients (median age 70 years [IQR: 50 years-86 years]; 48% female). Reduction in LV end-diastolic volumes (P = 0.002) independent of CRT pacing were more prominent than corresponding reductions in right ventricular end-diastolic volumes (P = 0.16). A clear dependence of the optimal CRT pacing mode (BIVP vs LVP) on the PR interval (P = 0.0006) was demonstrated. The LVEF and RVEF improved more with BIVP than LVP with PR intervals ≥240 milliseconds (P = 0.025 and P = 0.002, respectively); the optimal mode (BIVP vs LVP) was variable with PR intervals <240 milliseconds. A lower pre-CRT displacement encoding with stimulated echoes CURE-SVD was associated with greater improvements in the post-CRT CURE-SVD (r = -0.69; P < 0.001), LV end-systolic volume (r = -0.58; P < 0.001), and LVEF (r = -0.52; P < 0.001).

CONCLUSIONS

CMR evaluation with assessment of multiple pacing modes during a single scan after CRT is feasible and provides useful information for patient care with respect to response and the optimal pacing strategy.

Tricuspid regurgitation associated with implantable electrical device insertion: A systematic review and meta-analysis

BACKGROUND

Implantable cardioverter defibrillator (ICD) and permanent pacemaker (PPM) lead placement may worsen or result in tricuspid regurgitation (TR). While the association between lead placement and the incidence of TR has been established, current understanding of this problem remains incomplete. This systematic review and meta-analysis sought to pool the existing evidence to better understand the occurrence and severity of TR associated with cardiac implantable electrical device (CIED) insertion.

METHODS

An electronic search was performed to identify all relevant studies published from 2000 to 2018. Overall, 15 studies were selected for the analysis comprising 4019 patients with data reported on TR development following ICD or PPM lead placement. Demographic information, perioperative clinical variables, and clinical outcome measures, including pre and postoperative echocardiographic TR grade changes, were extracted and pooled for systematic review.

RESULTS

Mean patient age was 69 years [95% CI: 64.62-73.59], and 63% [95% CI: 57-68] were male. Devices implanted included ICD in 57% [95%CI: 43-70] and PPM in 41% [95%CI: 31-52]. The most common indications for pacemaker implantation were sick sinus syndrome in 22% [95% CI: 22-37] and AV block in 21% [95%CI:12-34. The commonest indications for ICD implantation were primary and secondary prevention of sudden cardiac death. Atrial fibrillation was present in 37% [95%CI: 28-46] and congestive heart failure in 15% [95%CI: 2-57]. Baseline distribution of TR grades were as follows: grade 0/1 TR in 89% [95%CI: 82-93], grade 2 TR in 8% [95%CI: 5-13], grade 3 TR in 2% [95%CI: 0-7] and grade 4 TR in 2% [95%CI: 1-4]. Post-procedure, grade 0/ 1 TR decreased to 68% [95% CI: 51-81] (p < 0.01), grade 2 TR increased to 21% [15-28] (p < 0.01), grade 3 TR increased to 13% [95%CI: 5-32] (p = 0.02), and grade 4 TR increased to 7% [95%CI: 5-9] (p < 0.01).

CONCLUSION

ICD and PPM lead placement is associated with increased TR post-procedure. Further studies are warranted to evaluate changes in TR grade in the long term.

Appropriate ICD Interventions for Ventricular Arrhythmias Are Predicted by Higher Syntax Scores I and II in Patients with Ischemic Heart Disease

Aims. The occurrence of ventricular arrhythmias (VAs) in ischemic heart disease (IHD) patients is related to the presence and extent of fibrotic/scar tissue. As coronary atherosclerosis is the underlying cause of myocardial ischemia and fibrosis, in IHD patients implanted with an implantable cardioverter defibrillator (ICD) we investigated the relation between the VA burden and the complexity of coronary atherosclerotic lesions. Methods and results. In IHD patients who underwent coronary angiography and ICD implant, the Syntax scores I and II (SSI-II), as index of the severity of the coronary atherosclerotic disease, and the occurrence of VA were assessed. Overall 144 patients were included (123 males). Of these 22 patients (15%) experienced at least one episode of VA (cycle length 298 ± 19 msec) that required ICD intervention. The number of episodes per patient and per year was 4 ± 6 and 2.8 ± 4, respectively. Patients that experienced a VA compared to those free from arrhythmic events did not have distinct baseline clinical characteristics except for a higher SS I and SS II (21 (IQR 13–38) vs. 16 (IQR 10–23); p = 0.037; and 50 (IQR 39–62) vs. 42 (IQR 34–50); p = 0.012). In the binary logistic regression analyses the SS I and II were the only independent predictors of VA occurrence. A higher SS II was also associated with an earlier time to first event (p = 0.005). Conclusion. Higher SS I-II scores reflect a more severe coronary atherosclerosis and are associated with a greater VA burden. Further studies are needed to better clarify the ability of SSI-II to stratify the risk of IHD patients to develop life-threatening VA.

Sudden Cardiac Death in Patients with Heart Disease and Preserved Systolic Function: Current Options for Risk Stratification

Sudden cardiac death (SCD) is the leading cause of cardiovascular mortality in patients with coronary artery disease without severe systolic dysfunction and in heart failure with preserved ejection fraction. From a global health perspective, while risk may be lower, the absolute number of SCDs in patients with left ventricle ejection fraction >35% is higher than in those with severely reduced left ventricle ejection fraction (defined as ≤35%). Despite these observations and the high amount of available data, to date there are no clear recommendations to reduce the sudden cardiac death burden in the population with mid-range or preserved left ventricle ejection fraction. Ongoing improvements in risk stratification based on electrophysiological and imaging techniques point towards a more precise identification of patients who would benefit from ICD implantation, which is still an unmet need in this subset of patients. The aim of this review is to provide a state-of-the-art approach in sudden cardiac death risk stratification of patients with mid-range and preserved left ventricular ejection fraction and one of the following etiologies: ischemic cardiomyopathy, heart failure, atrial fibrillation or myocarditis.

Patient with an implantable cardiac electrical stimulation device. What should the anesthesiologist know?

Patients with implantable electric stimulation devices are challenging to the anesthesiologist since these cases demand a comprehensive knowledge about how the device operates, the indications for the implant and the implications that must be addressed during the perioperative period . This article is intended to provide the reader with clear and structured information so that the anesthesiologist will be able to safely deal with the situation of a patient with an implantable cardiac stimulation device, who has been programmed for emergent surgery. A search for the scientific evidence available was conducted in Pubmed / Medline, ScienceDirect, OVID, SciELO), for a non-systematic review. The incidence of the use of cardiac electric stimulation devices has been growing. Their operation is increasingly complex, and demands being constantly updated on the knowledge in the area.

Use and Outcomes of Dual Chamber or Cardiac Resynchronization Therapy Defibrillators Among Older Patients Requiring Ventricular Pacing in the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

IMPORTANCE

Frequent right ventricular (RV) pacing can cause and exacerbate heart failure. Cardiac resynchronization therapy (CRT) has been shown to be associated with improved outcomes among patients with reduced left ventricular ejection fraction who need frequent RV pacing, but the patterns of use of CRT vs dual chamber (DC) devices and the associated outcomes among these patients in clinical practice is not known.

OBJECTIVE

To assess outcomes, variability in use of device type, and trends in use of device type over time among patients undergoing implantable cardioverter defibrillator (ICD) implantation who were likely to require frequent RV pacing but who did not have a class I indication for CRT.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used the National Cardiovascular Data Registry (NCDR) ICD Registry. A total of 3100 Medicare beneficiaries undergoing first-time implantation of CRT defibrillator (CRT-D) or DC-ICD from 2010 to 2016 who had a class I or II guideline ventricular bradycardia pacing indication but not a class I indication for CRT were included. Data were analyzed from August 2018 to October 2019.

EXPOSURES

Implantation of a CRT-D or DC-ICD.

MAIN OUTCOMES AND MEASURES

All-cause mortality, heart failure hospitalization, and complications were ascertained from Medicare claims data. Multivariable Cox proportional hazards models and Fine-Gray models were used to evaluate 1-year mortality and heart failure hospitalization, respectively. Multivariable logistic regression was used to evaluate 30-day and 90-day complications. All models accounted for clustering. The median odds ratio (MOR) was used to assess variability and represents the odds that a randomly selected patient receiving CRT-D at a hospital with high implant rates would receive CRT-D if they had been treated at a hospital with low CRT-D implant rates.

RESULTS

A total of 3100 individuals were included. The mean (SD) age was 76.3 (6.4) years, and 2500 (80.6%) were men. The 1698 patients (54.7%) receiving CRT-D were more likely than those receiving DC-ICD to have third-degree atrioventricular block (828 [48.8%] vs 432 [30.8%]; P < .001), nonischemic cardiomyopathy (508 [29.9%] vs 255 [18.2%]; P < .001), and prior heart failure hospitalizations (703 [41.4%] vs 421 [30.0%]; P < .001). Following adjustment, CRT-D was associated with lower 1-year mortality (hazard ratio [HR], 0.70; 95% CI, 0.57-0.87; P = .001) and heart failure hospitalization (subdistribution HR, 0.77; 95% CI, 0.61-0.97; P = .02) and no difference in complications compared with DC-ICD. Hospital variation in use of CRT was present (MOR, 2.00), and the use of CRT in this cohort was higher over time (654 of 1351 [48.4%] in 2010 vs 362 of 594 [60.9%] in 2016; P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study of older patients in contemporary practice undergoing ICD implantation with a bradycardia pacing indication but without a class I indication for CRT, CRT-D was associated with better outcomes compared with DC devices. Variability in use of device type was observed, and the rate of CRT implantation increased over time.

Heart Failure and Shared Decision-Making: Patients Open to Medication-Related Cost Discussions

BACKGROUND

Discussions of medication costs between patients and clinicians are infrequent and often suboptimal. In the context of recently introduced drugs that are effective but expensive, patients with heart failure with reduced ejection fraction provide an ideal population to understand the perspectives of patients with chronic illness on medication cost and cost discussions.

METHODS

To explore patients' perspectives on discussing out-of-pocket medication costs with clinicians, 49 adults, aged 44 to 70 years, with heart failure with reduced ejection fraction were recruited from outpatient heart failure clinics. Descriptive qualitative analysis was performed on open-ended text data.

RESULTS

Participants who had prior medication-related cost discussions described their experience as generally positive, but about half of the participants had never had a cost discussion with their clinician. Most participants were open to cost discussions with clinicians and preferred that the clinician initiate discussions regarding medication cost. Importantly, these preferences held constant across reported levels of financial burden.

CONCLUSIONS

These data suggest a substantial willingness on the part of patients with heart failure with reduced ejection fraction to incorporate cost discussions into their care and identify important aspects of these discussions for clinicians to consider when engaging in conversations where cost is relevant. Improving understanding about how to integrate patient preferences regarding cost discussions into clinical encounters is an important priority for advancing patient-centered care.

Association Between Industry Payments to Physicians and Device Selection in ICD Implantation

IMPORTANCE

Little is known about the association between industry payments and medical device selection.

OBJECTIVE

To examine the association between payments from device manufacturers to physicians and device selection for patients undergoing first-time implantation of a cardioverter-defibrillator (ICD) or cardiac resynchronization therapy-defibrillator (CRT-D).

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, patients who received a first-time ICD or CRT-D device from any of the 4 major manufacturers (January 1, 2016-December 31, 2018) were identified. The data from the National Cardiovascular Data Registry ICD Registry was linked with the Open Payments Program's payment data. Patients were categorized into 4 groups (A, B, C, and D) corresponding to the manufacturer from which the physician who performed the implantation received the largest payment. For each patient group, the proportion of patients who received a device from the manufacturer that provided the largest payment to the physician who performed implantation was determined. Within each group, the absolute difference in proportional use of devices between the manufacturer that made the highest payment and the proportion of devices from the same manufacturer in the entire study cohort (expected prevalence) was calculated.

EXPOSURES

Manufacturers' payments to physicians who performed an ICD or CRT-D implantation.

MAIN OUTCOMES AND MEASURES

The primary outcome of the study was the manufacturer of the device used for the implantation.

RESULTS

Over a 3-year period, 145 900 patients (median age, 65 years; 29.6% women) received ICD or CRT-D devices from the 4 manufacturers implanted by 4435 physicians at 1763 facilities. Among these physicians, 4152 (94%) received payments from device manufacturers ranging from $2 to $323 559 with a median payment of $1211 (interquartile range, $390-$3702). Between 38.5% and 54.7% of patients received devices from the manufacturers that had provided physicians with the largest payments. Patients were substantially more likely to receive devices made by the manufacturer that provided the largest payment to the physician who performed implantation than they were from each other individual manufacturer. The absolute differences in proportional use from the expected prevalence were 22.4% (95% CI, 21.9%-22.9%) for manufacturer A; 14.5% (95% CI, 14.0%-15.0%) for manufacturer B; 18.8% (95% CI, 18.2%-19.4%) for manufacturer C; and 30.6% (95% CI, 30.0%-31.2%) for manufacturer D.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, a large proportion of ICD or CRT-D implantations were performed by physicians who received payments from device manufacturers. Patients were more likely to receive ICD or CRT-D devices from the manufacturer that provided the highest total payment to the physician who performed an ICD or CRT-D implantation than each other manufacturer individually.

Integration of novel monitoring devices with machine learning technology for scalable cardiovascular management

Ambulatory monitoring is increasingly important for cardiovascular care but is often limited by the unpredictability of cardiovascular events, the intermittent nature of ambulatory monitors and the variable clinical significance of recorded data in patients. Technological advances in computing have led to the introduction of novel physiological biosignals that can increase the frequency at which abnormalities in cardiovascular parameters can be detected, making expert-level, automated diagnosis a reality. However, use of these biosignals for diagnosis also raises numerous concerns related to accuracy and actionability within clinical guidelines, in addition to medico-legal and ethical issues. Analytical methods such as machine learning can potentially increase the accuracy and improve the actionability of device-based diagnoses. Coupled with interoperability of data to widen access to all stakeholders, seamless connectivity (an internet of things) and maintenance of anonymity, this approach could ultimately facilitate near-real-time diagnosis and therapy. These tools are increasingly recognized by regulatory agencies and professional medical societies, but several technical and ethical issues remain. In this Review, we describe the current state of cardiovascular monitoring along the continuum from biosignal acquisition to the identification of novel biosensors and the development of analytical techniques and ultimately to regulatory and ethical issues. Furthermore, we outline new paradigms for cardiovascular monitoring.

Advances in cardiovascular monitoring technologies have resulted in an influx of consumer-targeted wearable sensors that have the potential to detect numerous heart conditions. In this Review, Krittanawong and colleagues describe processes involved in biosignal acquisition and analysis of cardiovascular monitors, as well as their associated ethical, regulatory and legal challenges.

Advances in the use of cardiovascular monitoring technologies, such as the development of novel portable sensors and machine learning algorithms that can provide near-real-time diagnosis, have the potential to provide personalized care.

Wearable sensor technologies can detect numerous biosignals, such as cardiac output, blood-pressure levels and heart rhythm, and can integrate multiple modalities.

The use of novel biosignals for diagnosis raises concerns regarding accuracy and actionability within clinical guidelines, in addition to medical, legal and ethical issues.

Machine learning-based interpretation of biosensor data can facilitate rapid evaluation of the haemodynamic consequences of heart failure or arrhythmias, but is limited by the presence of noise and training data that might not be representative of the real-world clinical setting.

The use of data derived from cardiovascular monitoring devices is associated with numerous challenges, such as data security, accessibility and ownership, in addition to other ethical and regulatory concerns.

Trends in Use and In-Hospital Outcomes of Subcutaneous Implantable Cardioverter Defibrillators in Patients Undergoing Long-Term Dialysis

BACKGROUND AND OBJECTIVES

Patients on dialysis are at high risk of complications related to implantable cardioverter defibrillator (ICD) implantation; use of subcutaneous ICDs may be preferred over transvenous devices due to lower risk of bloodstream infection and interference with vascular access sites. We evaluated trends in use and in-hospital outcomes of subcutaneous compared with transvenous ICDs among patients on dialysis in the United States.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective analysis of ICD implants from 2012 to 2018 among patients on dialysis reported to the National Cardiovascular Data Registry ICD Registry, a nationally representative US ICD Registry. We examined overall trends in subcutaneous ICD adoption as a proportion of all eligible ICD implants among patients on dialysis and then compared in-hospital outcomes between eligible subcutaneous ICD and transvenous ICD recipients using inverse probability of treatment weighting.

RESULTS

Of the 23,136 total ICD implants in patients on dialysis during the study period, 3195 (14%) were subcutaneous ICDs. Among eligible first-time ICD recipients on dialysis, the proportion of subcutaneous ICDs used increased yearly from 10% in 2012 to 69% in 2018. In propensity score-weighted analysis of 3327 patients, compared with transvenous ICDs, patients on dialysis receiving subcutaneous ICDs had a higher rate of in-hospital cardiac arrest (2% versus 0.4%, P=0.002), but there was no significant difference in total in-hospital complications (2% versus 1%, P=0.08), all-cause death, or length of hospital stay.

CONCLUSIONS

The utilization of subcutaneous ICDs among US patients on dialysis has been steadily increasing. The overall risk of short-term complications is low and comparable with transvenous ICDs, but higher risks of in-hospital cardiac arrest merits closer monitoring and further investigation.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_09_23_CJN07920520.mp3.

Social cognitive intervention following an initial implantable cardioverter defibrillator: Better treatment response for secondary versus primary prevention

BACKGROUND

The patient + partner (P+P) is a patient/partner-focused social cognitive intervention with demonstrated efficacy to improve outcomes following an initial implantable cardioverter defibrillator (ICD). Little is known about how the patient response may differ by ICD implant indication. The aim of this study was to examine the response to intervention for patients with an initial ICD by reasons for primary versus secondary ICD indication.

METHOD

A longitudinal secondary analysis of data from a randomized clinical trial testing the P+P intervention examined patient health outcomes over 12 months, stratified by the indication for the ICD: primary prevention without cardiac resynchronization therapy (CRT) (1o No CRT, n = 100), primary prevention with CRT (1o CRT, n = 78), secondary prevention after cardiac arrest (2° Cardiac Arrest, n = 66), and secondary prevention for other arrhythmias (2o Other, n = 57). Outcomes included physical and mental health status (Short-Form-36 Physical Component Summary and Mental Component Summary), physical symptoms (Patient Concerns Assessment), depression (Patient-Health-Questionniare-9), and anxiety (State-Trait Anxiety Inventory).

RESULTS

Participants (n = 301) were on average 64 years old, primarily male (73.7%) and Caucasian (91%) with reduced ejection fraction (34%). There were no baseline differences between ICD groups for all outcomes (P > .05). Patients in the 2° Cardiac Arrest group showed greater improvement from baseline to 3 months in physical and mental health outcomes. The 2° Cardiac Arrest group had better physical (F = 11.48, P = .004) and mental health (F = 4.34, P = .038) and less severe physical (z = 2.24, P = 0.013) and depressive symptoms (z = 2.71, P = .003) at 12 months compared to the 1o No CRT group.

CONCLUSION

The P+P intervention was more effective for promoting physical and psychological health outcomes for individuals receiving an ICD for 2o prevention after cardiac arrest.

Safety and Efficacy of Cardiovascular Implantable Electronic Device Extraction in Elderly Patients: A Meta-Analysis and Systematic Review

Background

Transvenous lead extraction of cardiovascular implantable electronic device (CIED) has been proven safe in the general patient population with the advances in extraction techniques. Octogenarians present a unique challenge given their comorbidities and the perceived increase in morbidity and mortality.

Objective

To assess the safety and outcomes of CIED extraction in octogenarians to younger patients.

Methods

We performed an extensive literature search and systematic review of studies that compared CIED extraction in octogenarians versus non-octogenarians. We separately assessed the rate of complete procedure success, clinical success, procedural mortality, major and minor complications. Risk ratio (RR) 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used due to heterogeneity across study cohorts.

Results

Seven studies with a total of 4,182 patients were included. There was no difference between octogenarians and non-octogenarians in complete procedure success (RR 1.01, 95% CI 1.00 - 1.02, p = 0.19) and clinical success (RR 1.01, 95% CI 1.00 - 1.01, p = 0.13). There was also no difference in procedural mortality (RR 1.43, 95% CI 0.46 - 4.39, p = 0.54), major complication (RR 1.40, 95% CI 0.68 - 2.88, p = 0.36), and minor complication (RR 1.43, 95% CI 0.90 - 2.29, p = 0.13).

Conclusion

In this study, there was no evidence to suggest a difference in procedural success and complication rates between octogenarians and younger patients. Transvenous lead extraction can be performed safely and effectively in the elderly population.

Evaluation of a Novel Educational Intervention to Improve Conversations About Implantable Cardioverter-Defibrillators Management in Patients with Advanced Heart Failure

Background: Implantable cardioverter-defibrillators (ICDs) reduce the incidence of sudden cardiac death for high-risk patients with heart failure (HF), but shocks from these devices can also cause pain and anxiety at the end of life. Although professional society recommendations encourage proactive discussions about ICD deactivation, clinicians lack training in conducting these conversations, and they occur infrequently. Methods: As part of a six-center randomized controlled trial, we evaluated the educational component of a multicomponent intervention shown to increase conversations about ICD deactivation by clinicians who care for a subset of patients with advanced HF. This consisted of a 90-minute training workshop designed to improve the quality and frequency of conversations about ICD management. To characterize its utility as an isolated intervention, we compared HF clinicians' pre- and postworkshop scores (on a 5-point Likert scale) assessing self-reported confidence and skills in specific practices of advance care planning, ICD deactivation discussions, and empathic communication. Results: Forty intervention-group HF clinicians completed both pre- and postworkshop surveys. Preworkshop scores showed high baseline levels of confidence (4.36, standard deviation [SD] = 0.70) and skill (4.08, SD = 0.72), whereas comparisons of pre- and postworkshop scores showed nonsignificant decreases in confidence (-1.16, p = 0.252) and skill (-0.20, p = 0.843) after the training session. Conclusions: Our findings showed no significant changes in self-assessment ratings immediately after the educational intervention. However, our data did demonstrate that HF clinicians had high baseline self-perceptions of their skills in advance care planning conversations and appear to be well-primed for further professional development to improve communication in the setting of advanced HF.

Clinical factors associated with baseline history of atrial fibrillation and subsequent clinical outcomes following initial implantable cardioverter‐defibrillator placement

BACKGROUND

Atrial fibrillation (AF) is frequently present in patients with heart failure (HF) and an implantable cardioverter-defibrillator (ICD). This study aims to identify clinical factors associated with a baseline history of AF in ICD recipients, and compares subsequent clinical outcomes in those with and without a baseline history of AF.

METHODS

We studied 566 consecutive first-time ICD recipients at an academic center between 2011 and 2018. Logistic regression multivariable analyses were used to identify clinical factors associated with a baseline history of AF at the time of ICD implant. Cox-proportional hazard regression models were constructed for multivariate analysis to examine associations between a baseline history of AF with subsequent clinical outcomes, including ICD therapies, HF readmission, and all-cause mortality.

RESULTS

Of all patients, 201 (36%) had a baseline history of AF at the time of ICD implant. In multivariate analyses, clinical factors associated with a baseline history of AF included hypertension, valvular heart disease, body weight, PR interval, and serum creatinine level. After multivariate adjustment for potential confounders, a baseline history of AF was associated with an increased risk of anti-tachycardia pacing (HR = 1.84, 95% CI = 1.19-2.85, P = .006), appropriate ICD shocks (HR = 1.80, 95% CI = 1.05-3.09, P = .032), and inappropriate ICD shocks (HR = 3.72, 95% CI = 1.7-7.77, P = .0001), but not other adverse outcomes.

CONCLUSION

Among first-time ICD recipients, specific clinical characteristics were associated with a baseline history of AF at the time of ICD implant. After adjustment for potential confounders, a baseline history of AF was associated with a higher risk of all ICD therapies in follow-up.

Effect of physical and psychocognitive function and perceived health status on 12-month adverse cardiac events among implantable cardioverter-defibrillator recipients

BACKGROUND

Post-implant recovery in patients with implantable cardioverter-defibrillators (ICDs) is often compromised because of reduced physical and psycho-cognitive function and poor health perception, leading to short event-free survival.

OBJECTIVES

To examine the effects of psychocognitive function, health perception, and ICD-related factors on 12-month cardiac events among ICD patients.

METHODS

Using a prospective study design, ICD patients underwent baseline assessment and were followed for 12 months to assess cardiac events.

RESULTS

Cardiac events occurred in 14 patients (18.9%) (N = 74: age, 58 years; primary ICDs, 45.9%). Time after ICD implant (odds ratio [OR] = 1.002; p = .028) and executive function (OR = 1.021; p = .027) were significant predictors of 12-month cardiac events, while other physical and psychological indices were not.

CONCLUSIONS

Reduced executive function and longer time after implant predicted the events. Healthcare professionals need to assess executive function and provide treatment and support to improve executive function.

A real-time system for selectively sensing and pacing the His-bundle during sinus rhythm and ventricular fibrillation

Background

The His–Purkinje (HP) system provides a pathway for the time-synchronous contraction of the heart. His bundle (HB) of the HP system is gaining relevance as a pacing site for treating non-reversible bradyarrhythmia despite limited availability of tools to identify the HB. In this paper, we describe a real-time stimulation and recording system (rt-SRS) to investigate using multi-electrode techniques to identify and selectively pace the HB. The rt-SRS can not only be used in sinus rhythm, but also during ventricular fibrillation (VF). The rt-SRS will also help investigate the so far unknown causal effects of selectively pacing the HB during VF.

Methods

The rt-SRS consists of preamplifiers, data acquisition cards interfaced with a real-time controller, a current source, and current routing switches on a remote computer, which may be interrupted to stimulate using a host machine. The remote computer hosts a series of algorithms designed to aid in identifying electrodes directly over the HB, to accurately detect activation rates without over-picking, and to deliver stimulation pulses. The performance of the rt-SRS was demonstrated in seven isolated, perfused rabbit hearts.

Results

The rt-SRS can visualize up to 96 channels of raw data, and spatial derivative data at 6.25-kHz sampling rate with an input-referred noise of 100 µV. The rt-SRS can send up to ± 150 V of stimuli pulses to any of the 96 channels. In the rabbit experiments, HB activations were detected in 18 ± 6.8% of the 64 electrodes used during VF.

Conclusions

The rt-SRS is capable of measuring and responding to cardiac electrophysiological phenomena in real-time with precisely timed and placed electrical stimuli. This rt-SRS was shown to be an effective research tool by successfully detecting and quantifying HB activations and delivering stimulation pulses to selected electrodes in real-time.

Yazd Province of Iran ICD Registry for the Years 2014-2016

OBJECTIVE

This study aimed to investigate the trends in the care of patients undergoing implantable cardioverter-defibrillator (ICD) implantation in our region and to analyze whether the quality of care is the same as the other centers or not?

METHODS

Adult patients with an indication for ICD implants were enrolled in our registry and followed over a 19-43-month period.

RESULTS

The ICD implantation rate was 100/million per year. The mean age of patients treated with ICD was 62.36 (±12.93) years old and the majority of patients were men (77.6%). Most patients had ischemic heart failure (65.2%). Nearly half of the patients had NYHA class III (53.8%) and the mean of ejection fraction was 26.7 (±9.8%). ICDs were frequently implanted for primary prevention (71.9%). Single chamber ICDs (ICD-VR) were chosen in 25.2%, dual-chamber ICDs in 37.1% (ICD-DR) and biventricular ICDs (CRT-D) in 37.6%, respectively. Complications related to ICD implantation occurred in about 7.49% of all procedures. During follow-up period death occurred in 14.8% of our patients. Also, 13.3% of patients received ICD shock which was appropriate in 71% of patients.

CONCLUSIONS

In comparison between our registry and NCDR registry, baseline patient characteristics and ICD type were almost the same, but the complication rate was higher. There is still a need to perform a large multicenter registry in our community to improve our knowledge in this Era.

Decision-making regarding primary prevention implantable cardioverter-defibrillators among older adults

Most implantable cardioverter defibrillators (ICDs) are implanted for the purpose of primary prevention of sudden cardiac death among older patients with heart failure with reduced ejection fraction. Shared decision‐making prior to device implantation is guideline‐recommended and payer‐mandated. This article summarizes patient and provider attitudes toward device placement, device efficacy and effectiveness, potential periprocedural complications, long‐term events such as shocks, quality of life, costs, and shared decision‐making principles and recommendations. Most patients eligible for an ICD anticipate more than 10 years of survival. Physicians are less likely to offer an ICD to patients ≥80 years of age given a perceived lack of benefit. There is a dearth of data from randomized clinical trials addressing device efficacy among older patients; there is a need for more research in this area. However, currently available data support the use of ICDs irrespective of age provided life expectancy exceeds 1 year. Advanced age is independently associated with complications at the time of device placement but not the risk of device infection. The risk of inappropriate shock may be comparable or lower than that of younger patients. While quality of life is generally not adversely impacted by an ICD, a subset of patients experience post‐traumatic stress disorder. ICDs are cost‐effective from societal and health care sector perspectives; however, out‐of‐pocket costs vary according to insurance type and level. Shared decision‐making encounters may be incremental and iterative in nature. Providers are encouraged to partner with their patients, providing them counsel tailored to their values, preferences, and clinical presentation inclusive of age.

CMR DENSE and the Seattle Heart Failure Model Inform Survival and Arrhythmia Risk After CRT

OBJECTIVES

This study sought to determine if combining the Seattle Heart Failure Model (SHFM-D) and cardiac magnetic resonance (CMR) provides complementary prognostic data for patients with cardiac resynchronization therapy (CRT) defibrillators.

BACKGROUND

The SHFM-D is among the most widely used risk stratification models for overall survival in patients with heart failure and implantable cardioverter-defibrillators (ICDs), and CMR provides highly detailed information regarding cardiac structure and function.

METHODS

CMR Displacement Encoding with Stimulated Echoes (DENSE) strain imaging was used to generate the circumferential uniformity ratio estimate with singular value decomposition (CURE-SVD) circumferential strain dyssynchrony parameter, and the SHFM-D was determined from clinical parameters. Multivariable Cox proportional hazards regression was used to determine adjusted hazard ratios and time-dependent areas under the curve for the primary endpoint of death, heart transplantation, left ventricular assist device, or appropriate ICD therapies.

RESULTS

The cohort consisted of 100 patients (65.5 [interquartile range 57.7 to 72.7] years; 29% female), of whom 47% had the primary clinical endpoint and 18% had appropriate ICD therapies during a median follow-up of 5.3 years. CURE-SVD and the SHFM-D were independently associated with the primary endpoint (SHFM-D: hazard ratio: 1.47/SD; 95% confidence interval: 1.06 to 2.03; p = 0.02) (CURE-SVD: hazard ratio: 1.54/SD; 95% confidence interval: 1.12 to 2.11; p = 0.009). Furthermore, a favorable prognostic group (Group A, with CURE-SVD <0.60 and SHFM-D <0.70) comprising approximately one-third of the patients had a very low rate of appropriate ICD therapies (1.5% per year) and a greater (90%) 4-year survival compared with Group B (CURE-SVD ≥0.60 or SHFM-D ≥0.70) patients (p = 0.02). CURE-SVD with DENSE had a stronger correlation with CRT response (r = -0.57; p < 0.0001) than CURE-SVD with feature tracking (r = -0.28; p = 0.004).

CONCLUSIONS

A combined approach to risk stratification using CMR DENSE strain imaging and a widely used clinical risk model, the SHFM-D, proved to be effective in this cohort of patients referred for CRT defibrillators. The combined use of CMR and clinical risk models represents a promising and novel paradigm to inform prognosis and device selection in the future.

Clinical experience of magnetic resonance imaging in patients with cardiac pacing devices: unrestricted patient population

Background

Magnetic resonance imaging (MRI) in patients with cardiac pacing devices has become available despite previously being considered absolutely contraindicated. However, most institutional safety protocols have included several limitations on patient selection, leaving MRI unavailable for many patients.

Purpose

To evaluate the first 1000 MRI examinations conducted on patients with cardiac pacing devices at Helsinki University Hospital for any potential safety hazards and also to evaluate the long-term functionality of the safety protocol in “real-life” clinical practice.

Material and Methods

A total of 1000 clinically indicated MRI scans were performed with a 1.5-T MRI scanner according to the safety protocol. The following information was collected from the electronic medical record (EMR): patients’ date of birth; sex; pacing device generator model; date of MRI scan; date of the latest pacing device generator implantation; and the body region scanned. The EMR of these patients was checked and especially searched for any pacing device related safety hazards or adverse outcomes during or after the MRI scan.

Results

Only one potentially dangerous adverse event was noted in our study group. In addition, patients with abandoned leads, temporary pacing devices, and newly implanted pacing device generators were scanned successfully and safely.

Conclusion

MRI scans can be performed safely in patients with cardiac pacing devices if the dedicated safety protocol is followed.

Facility-Level Variation and Clinical Outcomes in Use of Cardiac Resynchronization Therapy With and Without an Implantable Cardioverter-Defibrillator

BACKGROUND

Little is known about real-world facility-level preferences for cardiac resynchronization therapy devices with (CRT-D) and without (CRT-P) defibrillator backup. We quantify this variation at the facility level and exploit this variation to compare outcomes of patients receiving these 2 devices.

METHODS AND RESULTS

Claims data from fee-for-service Medicare beneficiaries were used to identify new CRT-P and CRT-D implants, 2006 to 2012. We modeled factors associated with receipt of each device, and compared mortality, hospitalizations, and reoperations for patients receiving each using both logistic regression and instrumental variable analysis to account for confounding. Among 71 459 device recipients (CRT-P, 11 925; CRT-D, 59 534; 31% women), CRT-P recipients were older, more likely to be women, and had more comorbidities. Variation in device selection among facilities was substantial: After adjustment for patient characteristics, the odds of receiving a CRT-P (versus CRT-D) device were 7.6× higher for a patient treated at a facility in the highest CRT-P use quartile versus a facility in the lowest CRT-P use quartile. Logistic modeling suggested a survival advantage for CRT-D devices but with falsification end points indicating residual confounding. By contrast, in the instrumental variable analysis using facility variability as the proposed instrument, clinical characteristics and falsification end points were well balanced, and 1-year mortality in patients who received CRT-P versus CRT-D implants did not differ, while CRT-P patients had a lower probability of hospitalizations and reoperations in the year following implant.

CONCLUSIONS

CRT-P versus CRT-D selection varies substantially among facilities, adjusted for clinical factors. After instrumental variable adjustment for clinical covariates and facility preference, survival was no different between the devices. Therefore, CRT-P may be preferred for Medicare beneficiaries considering new CRT implantation.