[Whether to implant a defibrillator or not? The Possibility of Using the MADIT-ICD Benefit Score Calculator in Real Practice].

AIM: To study the predictive capabilities of the MADIT-ICD Benefit Score calculator in assessing the benefit of implantable cardioverter defibrillator (ICD) placement for the primary prevention of sudden cardiac death (SCD). MATERIAL AND METHODS: This study included 388 patients with NYHA II-IV functional class chronic heart failure (CHF) with a left ventricular ejection fraction (LVEF) ≤35 % who underwent ICD placement for the primary prevention of SCD. Patients were followed up for two years to record the endpoints of first-time paroxysmal sustained ventricular tachyarrhythmia (VT) or non-arrhythmic death. RESULTS: According to the results of calculation with the MADIT-ICD Benefit Score calculator, 276 (71 %) patients had a high risk of VT (score ≥7) and 150 (39 %) had a high risk of non-arrhythmic death (score ≥3). 336 (94%) patients would benefit from an ICD: 148 (38 %) with a high level of probability and 218 (56 %) with a medium level of probability. According to the incidence of endpoints, VT episodes predominated in the low-ICD benefit group (36%), while the high-ICD benefit group had a relatively high incidence of non-arrhythmic death (12%). CONCLUSION: The results obtained for a cohort of Russian patients with CHF and reduced LVEF indicated that the use of the MADIT-ICD Benefit Score in routine clinical practice does not improve the stratification of SCD risk compared to the traditional approach to selecting patients with CHF for ICD based on the LVEF value.

Multi-phase implementation of automated external defibrillator use by nurses during in-hospital cardiac arrest and its impact on survival.

OBJECTIVE: We sought to evaluate the impact of a medical directive allowing nurses to use defibrillators in automated external defibrillator-mode (AED) on in-hospital cardiac arrest (IHCA) outcomes. METHODS: We completed a health record review of consecutive IHCA for which resuscitation was attempted using a pragmatic multi-phase before-after cohort design. We report Utstein outcomes before (Jan.2012-Aug.2013;Control) the implementation of the AED medical directive following usual practice (Sept.2013-Aug.2016;Phase 1), and following the addition of a theory-based educational video (Sept.2016-Dec.2017;Phase 2). RESULTS: There were 753 IHCA with the following characteristics (Before n = 195; Phase 1n = 372; Phase 2n = 186): mean age 66, 60.0% male, 79.3% witnessed, 29.1% noncardiac-monitored medical ward, 23.9% cardiac cause, and initial ventricular fibrillation/tachycardia (VF/VT) 27.2%. Comparing the Before, Phase 1 and 2: an AED was used 0 time (0.0%), 21 times (5.7%), 15 times (8.1%); mean times to 1st analysis were 7 min, 3 min and 1 min (p < 0.0001); mean times to 1st shock were 12 min, 10 min and 8 min (p = 0.32); return of spontaneous circulation (ROSC) was 63.6%, 59.4% and 58.1% (p = 0.77); survival was 24.6%, 21.0% and 25.8% (p = 0.37). Among IHCA in VF/VT (n = 165), time to 1st analysis and 1st shock decreased by 5 min (p = 0.01) and 6 min (p = 0.23), and ROSC and survival increased by 3.0% (p = 0.80) and 15.6% (p = 0.31). There was no survival benefit overall (1.2%; p = 0.37) or within noncardiac-monitored areas (-7.2%; p = 0.24). CONCLUSIONS: The implementation of a medical directive allowing for AED use by nurses successfully improved key outcomes for IHCA victims, particularly following the theory-based education video and among the VF/VT group.

Commotio Cordis in Non-Sport-Related Events: A Systematic Review.

BACKGROUND: Commotio cordis is an increasingly recognized cause of sudden cardiac death. Although commonly linked with athletes, many events occur in non-sport-related settings. OBJECTIVES: The goal of this study was to characterize and compare non-sport-related vs sport-related commotio cordis. METHODS: PubMed and Embase were searched for all cases of commotio cordis from inception to January 5, 2022. RESULTS: Of 334 commotio cordis cases identified, 121 (36%) occurred in non-sport-related contexts, which included assault (76%), motor vehicle accidents (7%), and daily activities (16%). Projectiles were implicated significantly less in non-sport-related events (5% vs 94%, respectively; P < 0.001). Nonprojectile etiologies in non-sport-related events mostly consisted of impacts with body parts (79%). Both categories affected similar younger aged demographic (P = 0.10). The proportion of female victims was significantly higher in non-sport-related events (13% vs 2%, respectively; P = 0.025). Mortality was significantly higher in non-sport-related events (88% vs 66%, respectively; P < 0.001). In non-sport-related events, rates of cardiopulmonary resuscitation (27% vs 97%, respectively; P < 0.001) and defibrillation (17% vs 81%, respectively; P < 0.001) were both lower and resuscitation was more commonly delayed beyond 3 min (80% vs 5%, respectively; P < 0.001). CONCLUSIONS: Commotio cordis occurs across a spectrum of non-sport-related settings including assault, motor vehicle accidents, and daily activities. Both categories affected a younger and male-predominant demographic. Mortality is higher in non-sport-related commotio cordis, likely owing to lower rates of cardiopulmonary resuscitation, defibrillation, automated external defibrillator availability, and extended time to resuscitation. Increased awareness of non-sport-related commotio cordis is essential to develop a means of prevention and mortality reduction, with earlier recognition and prompt resuscitation measures.

Age differences of patients treated with wearable cardioverter defibrillator: Data from a multicentre registry.

BACKGROUND: Wearable cardioverter defibrillators (WCD) are used as a 'bridging' technology in patients, who are temporarily at high risk for sudden cardiac death (SCD). Several factors should be taken into consideration, for example patient selection, compliance and optimal drug treatment, when WCD is prescribed. We aimed to present real-world data from seven centres from Germany and Switzerland according to age differences regarding the outcome, prognosis, WCD data and compliance. MATERIALS AND METHODS: Between 04/2012 and 03/2021, 1105 patients were included in this registry. Outcome data according to age differences (old ≥45 years compared to young <45 years) were analysed. At young age, WCDs were more often prescribed due to congenital heart disease and myocarditis. On the other hand, ischaemic cardiomyopathy (ICM) was more present in older patients. Wear days of WCD were similar between both groups (p = .115). In addition, during the WCD use, documented arrhythmic life-threatening events were comparable [sustained ventricular tachycardia: 5.8% vs. 7.7%, ventricular fibrillation (VF) .5% vs. .6%] and consequently the rate of appropriate shocks was similar between both groups. Left ventricular ejection fraction improvement was documented over follow-up with a better improvement in younger patients as compared to older patients (77% vs. 63%, p = .002). In addition, at baseline, the rate of atrial fibrillation was significantly higher in the older age group (23% vs. 8%; p = .001). The rate of permanent cardiac implantable electronic device implantation (CiED) was lower in the younger group (25% vs. 36%, p = .05). The compliance rate defined as wearing WCD at least 20 h per day was significantly lower in young patients compared to old patients (68.9% vs. 80.9%, p < .001). During the follow-up, no significant difference regarding all-cause mortality or arrhythmic death was documented in both groups. A low compliance rate of wearing WCD is predicted by young patients and patients suffering from non-ischaemic cardiomyopathies. CONCLUSION: Although the compliance rate in different age groups is high, the average wear hours tended to be lower in young patients compared to older patients. The clinical events were similar in younger patients compared to older patients.

A novel artificial intelligence based algorithm to reduce wearable cardioverter-defibrillator alarms.

BACKGROUND: The wearable cardioverter defibrillator (WCD) is an important tool in mitigating sudden cardiac death (SCD). The WCD provides patient alarms for detected arrhythmias or electrical noise/artifact. Some patients experience frequent alarms for artifact. We sought to evaluate the effects of a novel artificial intelligence algorithm to reduce alarms related to electrical noise or artifact (advanced arrhythmia discrimination algorithm, AArD). METHODS: A retrospective review of a large commercial database of prescribed WCD. Patients prescribed the WCD during the years 2017 (discrimination algorithm, DA group) or during 2019 (advanced arrhythmia discrimination algorithm, AArD) were analyzed. A total of 96,000 patients were sampled, 48,000 in the control group (using standard direct algorithm, DA) and compared to 48,000 in the intervention AArD (4000 per group per month) for 12 months. The AArD further discriminates ECG signals based on a machine-learning algorithm utilizing intensity and frequency beyond the standard DA. Outcomes regarding alarms, arrhythmias, and safety were analyzed. RESULTS: The AArD algorithm was associated with a significant decrease in frequency of alarms over the course of WCD use; 54% of patients in the AARD versus 27% of DA had 0 alarms (P < .001). In the entire cohort, there was a 56% relative reduction in alarms with the use of AArD. Appropriate arrhythmia treatment time was not significantly different between the groups (44 s DA vs 45 s AArD [p = ns]). CONCLUSIONS: A novel artificial intelligence algorithm reduces alarms without delaying appropriate therapy for VT/VF. These changes may improve compliance and quality of life in patients with a WCD.

The Case for Home AED in Children, Adolescents, and Young Adults Not Meeting Criteria for ICD.

Children, adolescents, and young adults with conditions such as cardiomyopathies and channelopathies are at higher risk of sudden cardiac death caused by lethal arrhythmias, especially ventricular fibrillation. Timely defibrillation saves lives. Patients thought to be at significantly high risk of sudden death typically undergo placement of an implantable cardioverter-defibrillator. Patients thought to be at lower risk are typically followed medically but do not undergo implantable cardioverter-defibrillator placement. However, low risk does not equal no risk. Compared with the general population, many of these patients are at significantly higher risk for lethal arrhythmias. We make the case that such individuals and families will benefit from having an at-home automatic external defibrillator. Used in conjunction with conventional measures such as training on cardiopulmonary resuscitation, an at-home automatic external defibrillator could lead to significantly shortened time to defibrillation with better overall and neurological survival. We recommend that the cost of such home automatic external defibrillators should be covered by medical insurance.

The value of wearable cardioverter defibrillator in adult patients with recent myocardial infarction: Economic and clinical implications from a health technology assessment perspective.

AIMS: Sudden cardiac death (SCD) causes high mortality and substantial societal burdens for healthcare systems (HSs). The risk of SCD is significantly increased in patients with reduced left ventricular ejection fraction after myocardial infarction (MI). Current guidelines recommend re-evaluation of cardioverter-defibrillator implantation 40 days post-MI, earliest. Medical therapy alone does not provide sufficient protection against SCD, especially in the first month post-MI, and needs time. Consequently, there is a gap in care of high-risk patients upon hospital discharge. The wearable cardioverter defibrillator (WCD) is a proven safe, effective therapy, which temporarily protects from SCD. Little information on WCD cost-effectiveness exists. We conducted this research to demonstrate the medical need of the device in the post-MI setting defining WCD cost-effectiveness. METHODS & RESULTS: Based on a randomized clinical trials (RCTs) and Italian and international data, we developed a Markov-model comparing costs, patient survival, and quality-of-life, and calculated the Incremental Cost-Effectiveness Ratio (ICER) of a WCD vs. current standard of care in post-MI patients. The rather conservative base case analysis - based on the RCT intention-to-treat results - produced an ICER of €47,709 per Quality Adjusted Life Year (QALY) gained, which is far lower than the accepted threshold of €60,000 in the Italian National HS. The ICER per Life Year (LY) gained was €38,276. CONCLUSION: WCD utilization in post-MI patients is clinically beneficial and cost-effective. While improving guideline directed patient care, the WCD can also contribute to a more efficient use of resources in the Italian HS, and potentially other HSs as well.

Real life experience with the wearable cardioverter-defibrillator in an international multicenter Registry.

Patients at high risk for sudden cardiac death (SCD) may benefit from wearable cardioverter defibrillators (WCD) by avoiding immediate implantable cardioverter defibrillator (ICD) implantation. Different factors play an important role including patient selection, compliance and optimal drug treatment. We aimed to present real world data from 4 centers from Germany and Switzerland. Between 04/2012 and 03/2019, 708 patients were included in this registry. Patients were followed up over a mean time of 28 ± 35.5 months. Outcome data including gender differences and different etiologies of cardiomyopathy were analyzed. Out of 708 patients (81.8% males, mean age 61.0 ± 14.6), 44.6% of patients had non-ischemic cardiomyopathy, 39.8% ischemic cardiomyopathy, 7.9% myocarditis, 5.4% prior need for ICD explantation and 2.1% channelopathy. The mean wear time of WCD was 21.2 ± 4.3 h per day. In 46% of patients, left ventricular ejection fraction (LVEF) was > 35% during follow-up. The younger the patient was, the higher the LVEF and the lower the wear hours per day were. The total shock rate during follow-up was 2.7%. Whereas an appropriate WCD shock was documented in 16 patients (2.2%), 3 patients received an inappropriate ICD shock (0.5%). During follow-up, implantation of a cardiac implantable electronic device was carried out in 34.5% of patients. When comparing German patients (n = 516) to Swiss patients (n = 192), Swiss patients presented with longer wear days (70.72 ± 49.47 days versus 58.06 ± 40.45 days; p = 0.001) and a higher ICD implantation rate compared to German patients (48.4% versus 29.3%; p = 0.001), although LVEF at follow-up was similar between both groups. Young age is a negative independent predictor for the compliance in this large registry. The most common indication for WCD was non-ischemic cardiomyopathy followed by ischemic cardiomyopathy. The compliance rate was generally high with a decrease of wear hours per day at younger age. Slight differences were found between Swiss and German patients, which might be related to differences in mentality for ICD implantation.

Prediction of early death after myocardial infarction in patients with reduced left ventricular ejection fraction. The search for new indications for cardioverter-defibrillator implantation (ICD).

BACKGROUND: The highest rate of death is in the first few weeks after myocardial infarction (MI). However, the assessment of indications for primary prevention implantable cardioverter-defibrillator (ICD) implantation should be postponed until at least 40 days after MI. AIMS: Our aim was to identify the subgroup of high-risk patients with reduced left ventricular ejection fraction (LVEF) who would benefit from primary prevention ICD implantation within 40 days of MI. METHODS: Out of 205 606 patients with MI, in this study, we included 18 736 patients treated invasively, with LVEF <40%, who survived until hospital discharge. Patients were divided into two groups according to the survival status at 40 days - patients who died within this period (n = 1331) and patients who survived (n = 17405). RESULTS: Among all patients who died within 12-months after MI, 37.7% did die during the first 40 days. Patients with cardiac arrest before hospital admission or within the first 48 hours of hospitalization (hazard ratio [HR], 3.35; 95% confidence interval [CI], 2.82-3.98; P <0.0001], cardiogenic shock before admission or during hospitalization (HR, 3.06; 95% CI, 2.62-3.59; P <0.0001), unsuccessful percutaneous coronary interventions (PCI; HR, 2.42; 95% CI, 2.11-2.84; P <0.0001), LVEF <20% (ref. LVEF ≥30%; HR, 2.75; 95% CI, 2.25-3.36; P <0.0001) had approximately threefold and patients with chronic kidney disease almost 1.5-times (HR, 1.25; 95% CI, 1.47-3.59; P = 0.0053) higher 40-day mortality compared to patients without these risk factors. The most striking differences in mortality between these subgroups were observed shortly after discharge. CONCLUSIONS: The highest risk of death in patients with reduced LVEF who survived until hospital discharge occurred within the first 40 days after MI. There is a possibility to select patients with the worst prognosis and treat them more aggressively.

Deep Brain Stimulation Generator Failure due to External Defibrillation in a Patient with Essential Tremor.

There exist only two case reports to date of open cardiac defibrillation with deep brain stimulator system (DBS) implantation. We report a 64-year-old male with DBS system in place for essential tremor who underwent cardiac defibrillation after cardiac arrest. Afterwards, his device impedances were all high and his tremor symptoms returned. Both problems resolved with implantation of a new generator and required no changes to the intracranial leads or extension cables. This is significantly different from the two previous reports. One included a significantly different DBS system relying on transcutaneous RF transmission and reported a lesioning effect after cardioversion. The other utilized a modern DBS system but reported damage to the generator and intracranial leads. We report that only the generator sustained damage, and that there were no intracranial changes that occurred.

BET 1: Can hands-on defibrillation be performed safely?

A short cut review was carried out to see whether hands-on defibrillation could be performed safely. 6 papers presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that hands-on defibrillation has the potential to be performed safely if the rescuer uses appropriate electrical insulating barriers such as polyethylene gloves or class 1 electrical insulating gloves. The safety profile of nitrile gloves is unclear. Since detection of shock was used as a proxy for safety, additional investigation is warranted before hands-on defibrillation becomes common practice.

Inflammatory markers in the diagnostic workup of pacemaker- and defibrillator­related infections in patients referred for transvenous lead extraction.

BACKGROUND: Infectious complications can be life­threatening in patients with permanent transvenous pacemakers and their diagnosis can be challenging. AIMS: The aim of the study was to assess the diagnostic utility of white blood cell (WBC) count and C­reactive protein (CRP) concentrations in infectious complications in patients with cardiac pacemakers. METHODS: The prospective study included patients who underwent transvenous lead extraction (TLE) due to various indications. The diagnosis of lead­dependent infective endocarditis (LDIE) was based on the modified Duke criteria, and the diagnosis of local infection was based on symptoms related to device pocket. The study population consisted of 640 patients: 63 (9.9%) with LDIE, 61 (9.5%) with local infection, and 516 controls (80.6%) referred for TLE due to noninfectious indications. We evaluated WBC count and CRP concentrations in each group of patients and assessed the predictive value of these tests for the diagnosis of LDIE and local infection. RESULTS: Patients with local infection did not differ in terms of median WBC and CRP values compared with controls (P = 0.99 and P = 0.13, respectively), whereas patients with LDIE had higher median WBC count and CRP level (P <0.001 and P <0.001, respectively). In the LDIE group, WBC diagnostic test showed 46.0% sensitivity, 95.3% specificity, 90.5% accuracy, 51.8% positive predictive value, and 94.2% negative predictive value. The diagnostic test based on CRP levels showed 84.1% sensitivity, 81.8% specificity, 82.0% accuracy, 33.5% positive predictive value, and 97.9% negative predictive value. CONCLUSIONS: In patients undergoing TLE due to infectious indications, inflammatory markers (WBC count, CRP level) were within normal range in the local­infection group and markedly elevated in the LDIE group. Inflammatory markers were useful to determine the extent of the infection in patients with local infection.

Ascending Defibrillation Waveform Significantly Reduces Myocardial Morphological Damage and Injury Current.

OBJECTIVES: This study tested the hypothesis that a biphasic defibrillation waveform with an ascending first phase (ASC) causes less myocardial damage by pathology and injury current than a standard biphasic truncated exponential (BTE) waveform in a swine model. BACKGROUND: Although lifesaving, defibrillation shocks have significant iatrogenic effects that reduce their benefit for patient survival. METHODS: An ASC waveform with an 8-ms linear ramp followed by an additional positive 0.5-ms decaying portion with amplitudes of 20 J (ASC 20J) and 25 J (ASC 25J) was used. The control was a 25-J BTE conventional waveform (BTE 25J) RESULTS: The ASC 20J and ASC 25J shocks were both successful in 6 of 6 pigs, but the BTE 25J was successful in only 6 of 14 pigs (p < 0.05). Post-shock ST-segment elevation (injury current) in the right ventricular electrode was significantly greater with BTE 25J than with ASC 20J and ASC 25J. With a blinded pathology reading, hemorrhage, inflammation, thrombi, and necrosis 24 h post-shock were significantly greater with BTE 25J than with ASC 20J and ASC 25J. Troponin levels were also markedly lower at 3, 4, 5, and 6 h post-shock. CONCLUSIONS: Defibrillation shocks cause electrophysiological, histological, and biochemical signs of myocardial damage and necrosis. These signs of damage are markedly less for an ASC waveform than for a conventional BTE waveform.

Inappropriately Firing Defibrillator: A Simulation Case for Emergency Medicine Residents.

Introduction: Emergency physicians must be able to manage inappropriately firing defibrillators. Many physicians may not experience this high-risk, low-frequency patient presentation during residency. We created this simulation to increase residents' knowledge of basic defibrillator function and confidence in managing patients with malfunctioning defibrillators. Methods: Sixteen emergency medicine residents of all levels of training participated in this curriculum. The educational experience began with a lecture. Residents then managed the simulated patient encounter in groups of four. The patient was a 63-year-old male presenting after feeling his defibrillator fire. He was found to have a supraventricular tachycardia with an inappropriately firing defibrillator. Learners needed to recognize the inappropriately firing defibrillator, inactivate it with a magnet, and treat the arrhythmia. Implementation of this scenario required audiovisual equipment and a simulation room equipped with high-fidelity simulator, patient monitor, code cart, defibrillator, and pacemaker magnet. Learners completed pre- and postcourse surveys to assess changes in baseline knowledge of defibrillator function and self-reported confidence in managing these complicated patients. Results: After participating in this educational intervention, residents improved their performance on a 10-question quiz from a class mean of 60% to 84% (p < .001). Residents also exhibited an increase in self-reported confidence in managing patients with inappropriately firing defibrillators (p < .001) and in knowing when to place a magnet over a patient's defibrillator (p < .001). Discussion: Residents demonstrated increased knowledge of defibrillator function as well as increased confidence in managing patients with malfunctioning defibrillators after participating in this simulation experience.