Transvenous lead extraction of implantable cardioverter-defibrillators: A comprehensive outcome-and risk factor analysis.

BACKGROUND: Device complications, such as infection or lead dysfunction necessitating transvenous lead extraction (TLE) are continuously rising amongst patients with transvenous implantable-cardioverter-defibrillator (ICD). OBJECTIVES: Aim of this study was to characterize the procedural outcome and risk-factors of patients with indwelling 1- and 2-chamber ICD undergoing TLE. METHODS: We conducted a subgroup analysis of all ICD patients in the GALLERY (GermAn Laser Lead Extraction RegistrY) database. Predictors for procedural failure and all-cause mortality were assessed. RESULTS: We identified 842 patients with an ICD undergoing TLE with the mean age of 62.8 ± 13.8 years. A total number of 1610 leads were treated with lead dysfunction (48.5%) as leading indication for extraction, followed by device-related infection (45.4%). Lead-per-patient ratio was 1.91 ± 0.88 and 60.0% of patients had dual-coil defibrillator leads. Additional extraction tools, such as mechanical rotating dilator sheaths and snares were utilized in 6.5% of cases. Overall procedural complications occurred in 4.3% with 2.0% major complications and a procedure-related mortality of 0.8%. Clinical success rate was 97.9%. All-cause in-hospital mortality was 3.4%, with sepsis being the leading cause for mortality. Multivariate analysis revealed lead-age ≥10 years (OR:5.82, 95%CI:2.1-16.6; p = .001) as independent predictor for procedural failure. Systemic infection (OR:9.57, 95%CI:2.2-42.4; p < .001) and procedural complications (OR:8.0, 95%CI:2.8-23.3; p < .001) were identified as risk factors for all-cause mortality. CONCLUSIONS: TLE is safe and efficacious in patients with 1- and 2-chamber ICD. Although lead dysfunction is the leading indication for extraction, systemic device-related infection is the main driver of all-cause mortality for ICD patients undergoing TLE.

Safety and Efficacy of Excimer Laser Powered Lead Extractions in Obese Patients: A GALLERY Subgroup Analysis.

BACKGROUND: The incidence of cardiac implantable electronic device (CIED)-related complications, as well as the prevalence of obesity, is rising worldwide. Transvenous laser lead extraction (LLE) has grown into a crucial therapeutic option for patients with CIED-related complications but the impact of obesity on LLE is not well understood. METHODS AND RESULTS: All patients (n = 2524) from the GermAn Laser Lead Extraction RegistrY (GALLERY) were stratified into five groups according to their body mass index (BMI, <18.5; 18.5-24.9; 25-29.9; 30-34.9; ≥35 kg/m2). Patients with a BMI ≥ 35.0 kg/m2 had the highest prevalence of arterial hypertension (84.2%, p < 0.001), chronic kidney disease (36.8%, p = 0.020) and diabetes mellitus (51.1%, p < 0.001). The rates for procedural minor (p = 0.684) and major complications (p = 0.498), as well as procedural success (p = 0.437), procedure-related (p = 0.533) and all-cause mortality (p = 0.333) were not different between groups. In obese patients (BMI ≥ 30 kg/m2), lead age ≥10 years was identified as a predictor of procedural failure (OR: 2.99; 95% CI: 1.06-8.45; p = 0.038). Lead age ≥10 years (OR: 3.25; 95% CI: 1,31-8.10; p = 0.011) and abandoned leads (OR: 3.08; 95% CI: 1.03-9.22; p = 0.044) were predictors of procedural complications, while patient age ≥75 years seemed protective (OR: 0.27; 95% CI: 0.08-0.93; p = 0.039). Systemic infection was the only predictor for all-cause mortality (OR: 17.68; 95% CI: 4.03-77.49; p < 0.001). CONCLUSIONS: LLE in obese patients is as safe and effective as in other weight classes, if performed in experienced high-volume centers. Systemic infection remains the main cause of in-hospital mortality in obese patients.

Transvenous lead extraction in patients with systemic cardiac device-related infection-Procedural outcome and risk prediction: A GALLERY subgroup analysis.

BACKGROUND: Transvenous lead extraction (TLE) has evolved as one of the most crucial treatment options for patients with cardiac device-related systemic infection (CDRSI). OBJECTIVE: The aim of this study was to characterize the procedural outcome and risk factors of patients with CDRSI undergoing TLE. METHODS: A subgroup analysis of patients with CDRSI of the GALLERY (GermAn Laser Lead Extraction RegistrY) database was performed. Predictors for complications, procedural failure, and all-cause mortality were evaluated. RESULTS: A total of 722 patients (28.6%) in the GALLERY had "systemic infection" as extraction indication. Patients with CDRSI were older (70.1 ± 12.2 years vs 67.3 ± 14.3 years; P < .001) and had more comorbidities than patients with local infections or noninfectious extraction indications. There were no differences in complete procedural success (90.6% vs 91.7%; P = .328) or major complications (2.5% vs 1.9%; P = .416) but increased procedure-related (1.4% vs 0.3%; P = .003) and all-cause in-hospital mortality (11.1% vs 0.6%; P < .001) for patients with CDRSI. Multivariate analyses revealed lead age ≥10 years as a predictor for procedural complications (odds ratio [OR] 3.23; 95% confidence interval [CI] 1.58-6.60; P = .001). Lead age ≥10 years (OR 2.57; 95% CI 1.03-6.46; P = .04) was also a predictor for procedural failure. We identified left ventricular ejection fraction <30% (OR 1.70; 95% CI 1.00-2.99; P = .049), age ≥75 years (OR 2.1; 95% CI 1.27-3.48; P = .004), chronic kidney disease (OR 1.92; 95% CI 1.17-3.14; P = .01), and overall procedural complications (OR 5.15; 95% CI 2.44-10.84; P < .001) as predictors for all-cause mortality. CONCLUSION: Patients with CDRSI undergoing TLE demonstrate an increased rate of all-cause in-hospital, as well as procedure-related mortality, despite having comparable procedural success rates. Given these data, it seems paramount to develop preventive strategies to detect and treat CDRSI in its earliest stages.

Atrial Fibrillation and Transvenous Lead Extraction-A Comprehensive Subgroup Analysis of the GermAn Laser Lead Extraction RegistrY (GALLERY).

Background: Atrial fibrillation is the most common arrhythmia and has been described as driver of cardiovascular morbidity and risk factor for cardiac device-related complications, as well as in transvenous lead extraction (TLE). Objectives: Aim of this study was to characterize the procedural outcome and risk-factors of patients with atrial fibrillation (AF) undergoing TLE. Methods: We performed a subgroup analysis of all AF patients in the GALLERY (GermAn Laser Lead Extraction RegistrY) database. Predictors for all-cause mortality were assessed. Results: A total number of 510 patients with AF were identified with a mean age of 74.0 ± 10.3 years. Systemic infection (38.4%) was the leading cause for TLE, followed by local infection (37.5%) and lead dysfunction (20.4%). Most of the patients (45.9%) presented with pacemaker systems to be extracted. The total number of leads was 1181 with a 2.3 ± 0.96 leads/patient. Clinical procedural success was achieved in 97.1%. Occurrence of major complications was 1.8% with a procedure-related mortality of 1.0%. All-cause mortality was high with 5.9% and septic shock being the most common cause. Systemic device infection (OR: 49.73; 95% CI: 6.56−377.09, p < 0.001), chronic kidney disease (CKD; OR: 2.67; 95% CI: 1.01−7.03, p = 0.048) and a body mass index < 21 kg/m2 (OR: 6.6; 95% CI: 1.68−25.87, p = 0.007) were identified as independent predictors for all-cause mortality. Conclusions: TLE in AF patients is effective and safe, but in patients with systemic infection the mortality due to septic shock is high. Systemic infection, CKD and body mass index <21 kg/m2 are risk factors for death in patient with AF undergoing TLE.

The GermAn Laser Lead Extraction RegistrY: GALLERY.

AIMS: The GermAn Laser Lead Extraction RegistrY: GALLERY is a retrospective, national multicentre registry, investigating the safety and efficacy of laser lead extraction procedures in Germany. METHODS AND RESULTS: Twenty-four German centres that are performing laser lead extraction have participated in the registry. All patients, treated with a laser lead extraction procedure between January 2013 and March 2017, were consecutively enrolled. Safety and efficacy of laser lead extraction were investigated. A total number of 2524 consecutive patients with 6117 leads were included into the registry. 5499 leads with a median lead dwell time of 96 (62-141) months were treated. The mean number of treated leads per patient was 2.18 ± 1.02. The clinical procedural success rate was 97.86% and the complete lead removal was observed in 94.85%. Additional extraction tools were used in 6.65% of cases. The rate of procedural failure was 2.14% with lead age ≥10 years being its only predictor. The overall complication rate was 4.32%, including 2.06% major and 2.26% minor complications. Procedure-related mortality was 0.55%. Female sex and the presence of abandoned leads were predictors for procedure-related complications. The all-cause in-hospital mortality was 3.56% with systemic infection being the strongest predictor, followed by age ≥75 years and chronic kidney disease. CONCLUSION: In the GALLERY, a high success- and low procedure-related complication rates have been demonstrated. In multivariate analysis, female sex and the presence of abandoned leads were predictors for procedure-related complications, while the presence of systemic infection, age ≥75 years, and chronic kidney disease were independent predictors for all-cause mortality.

Experience with a Wearable Cardioverter-defibrillator in 436 Patients.

The aim of the present study was to review the safety and efficiency of wearable cardioverter-defibrillators (WCDs) under current guideline-directed medical therapy (GDMT). We retrospectively analyzed 436 consecutive WCD patients seen in the years 2014-2020. Detected automatic arrhythmia alarm (AA) episodes were validated and classified as correct or incorrect. The positive predictive value (PPV) was calculated. GDMT was optimized in our outpatient clinic to maximal tolerated doses. During a total wear time (WT) of 23,527 days, 3,135 AAs were transmitted from 206 of 436 (47.2%) patients. Visual analysis revealed correct diagnoses of non-sustained ventricular tachycardia (VT) in 38 AAs from 6 patients (total PPV, 1.21%; PPV in VT patients, 41%); the remaining AAs were artifacts. No appropriate or inappropriate shocks and fatalities were recorded. LVEF significantly improved (P < .001) during the WT from 25% (range, 20%-30%) to 40% (range, 34%-46%). Defibrillators were implanted in 109 patients (27%). The PPV for VT of the WCD was very low. There were fewer instances of true VT than previously reported, and no shocks (appropriate or inappropriate) were delivered. The majority of patients greatly improved with GDMT, and device implantation rates were lower than previously reported. Improvements in arrhythmia detection algorithms are warranted. Based on our results, WCDs are rarely needed for lifesaving shocks under optimal GDMT.

Performance of implantable loop recorders. Role of R vector and detection algorithms.

INTRODUCTION: We evaluated the performance of implantable loop recorders (ILRs) with different detection algorithms and looked for artifacts and therapeutic consequences and their dependence on patient factors. METHODS AND RESULTS: 586 RevealLinq™ ILRs (first generation (NT): n = 335; second generation with TruRhythm™ (TR): n = 251) were implanted during 2014-2021 (syncope n = 206; embolic stroke of unknown source (ESUS) n = 380). Automatically detected EGM episodes (n = 18,650) were classified as correct or incorrect for asystole (AS), atrial fibrillation (AF) or tachycardia (TA). Incorrect episodes were caused by loss of signal (LO), noise (NO), extrasystole (ES) and T-wave oversensing (TWO). Left directed R axes, lower R-amplitudes and older age were related to artifacts. Results were separated by indication. In ESUS patients TR reduced total median artifact episodes: 0.6 (0-7) vs 0 (0-5) (p < 0.03) and median artifact examination time: 0.3 (0-3.5) vs 0 (0-2.5) (p = 0.03) per patient-year. This benefit is caused by significant reductions in total AS and ES-AS artifacts. The total positive predictive value (PPV) improved only in syncope patients (45 vs 71%, p = 0.002). Accordingly in syncope patients with TR more therapeutic consequences could be established (log rank 0.003). DISCUSSION: Patients R-axis and measured R-amplitudes during implantation predicted artifacts. This should be taken into account during ILR implantation. Total artifacts, AS artifacts and time spent for artifact analysis was reduced by the new TR detection algorithm in ESUS patients, whereas total artifacts remained unchanged in syncope patients despite reduction of AS artifacts. However TR had no effect on AF and TA episode detection and therefore has to be improved.

Induction of atrial fibrillation by implantable cardioverter-defibrillator shock: a forgotten entity.

A 65-year-old patient received an implantable cardioverter-defibrillator shock that resulted in ventricular tachycardia termination but induction of atrial fibrillation. The possible consequences of this rarely reported event are discussed.

Analysis of causes of death in patients with implanted defibrillators.

AIMS: Implantable cardioverter defibrillators (ICDs) are used for primary or secondary prevention of sudden cardiac death. We sought to clarify prognosis and causes of death after ICD implantation. METHODS AND RESULTS: A total of 2743 patients with ICDs implanted during 1990-2020 were analyzed. Median age was 68.5 (59.6-74.6) years; 21% women, median left ventricular ejection fraction (LVEF) was 30 (23-35), 52% had an ischemic etiology and 77% had a primary preventive indication. Mortality rate after 10 years was 22, 44, 55, and 72% in the 1st, 2nd, 3rd, and 4th age quartile, respectively. The calculated median sex and age adjusted loss of life years compared to the average German population was 9.7 (6.1-14.0) years. Prognosis was independently related to sex, age, LVEF, and glomerular filtration rate. 713 out of 852 deaths could be classified to a specific cause. Congestive heart failure (CHF) accounted for death in 214 (30%) and sudden death (SD) for 144 patients (20%). Postmortem interrogation of devices in 74 patients revealed VT/VF in 39 and no episodes in 35 patients. Cancer was identified as the cause of death in 121 patients (17% of cases), of which 36 were bronchial carcinomas. 73 (10%) of patients died due to infection. 67 patients (9%) died within 24 h of procedures. Compared to other causes, significantly more life years were lost associated with procedures and SD: 9.3 (5.7-12.9) versus 12.1 (7.4-15.2) and 11.9 (7.6-17.8) years. CONCLUSION: Life expectancy of ICD patients is lower than for the general population. Mortality is predominantly due to CHF, but there is still a considerable rate of SD. The occurrence of cancers, most importantly bronchial carcinomas, and infections, warrants protective measures. Some deaths during procedures are possibly preventable. Patients with ICDs comprise a vulnerable cohort, and treatment has to be optimized in many directions to improve prognosis.

Evaluation of Myocardial Gene Expression Profiling for Superior Diagnosis of Idiopathic Giant-Cell Myocarditis and Clinical Feasibility in a Large Cohort of Patients with Acute Cardiac Decompensation.

AIMS: The diagnostic approach to idiopathic giant-cell myocarditis (IGCM) is based on identifying various patterns of inflammatory cell infiltration and multinucleated giant cells (GCs) in histologic sections taken from endomyocardial biopsies (EMBs). The sampling error for detecting focally located GCs by histopathology is high, however. The aim of this study was to demonstrate the feasibility of gene profiling as a new diagnostic method in clinical practice, namely in a large cohort of patients suffering from acute cardiac decompensation. Methods and Results: In this retrospective multicenter study, EMBs taken from n = 427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age: 47.03 ± 15.69 years). In each patient, the EMBs were analyzed on the basis of histology, immunohistology, molecular virology, and gene-expression profiling. Out of the total of n = 427 patient samples examined, GCs could be detected in 26 cases (6.1%) by histology. An established myocardial gene profile consisting of 27 genes was revealed; this was narrowed down to a specified profile of five genes (CPT1, CCL20, CCR5, CCR6, TLR8) which serve to identify histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Once this newly established profiling approach was applied to the remaining patient samples, an additional n = 31 patients (7.3%) could be identified as having IGCM without any histologic proof of myocardial GCs. In a subgroup analysis, patients diagnosed with IGCM using this gene profiling respond in a similar fashion to immunosuppressive therapy as patients diagnosed with IGCM by conventional histology alone. Conclusions: Myocardial gene-expression profiling is a promising new method in clinical practice, one which can predict IGCM even in the absence of any direct histologic proof of GCs in EMB sections. Gene profiling is of great clinical relevance in terms of a) overcoming the sampling error associated with purely histologic examinations and b) monitoring the effectiveness of therapy.

Incidence of sleep apnea and association with atrial fibrillation in an unselected pacemaker population: Results of the observational RESPIRE study.

BACKGROUND: Patients with atrial fibrillation (AF) often have sleep apnea (SA), but diagnosis of SA with polysomnography is costly. SA monitoring is a pacemaker feature that measures respiratory disturbance index, the sum of abnormal respiratory events divided by sleep duration. OBJECTIVE: The purpose of this study was to evaluate the incidence and severity of SA and its association with AF in an unselected population fitted with pacemakers. METHODS: RESPIRE (REgistry of Sleep APnea monItoring and Atrial Fibrillation in pacemakeR patients) was a multicenter, international, observational, open-label study following adult subjects for 18 months after implantation with an SA monitoring-enabled dual-chamber pacemaker. Severe SA was defined as average respiratory disturbance index ≥20 from implantation to follow-up visit. The first co-primary end point was the difference in significant AF (cumulative AF episodes lasting ≥24 hours over 2 consecutive days) between subjects with severe and those nonsevere SA at 12 months in the full analysis set (N = 553). The second co-primary end point was the rate of major serious adverse events at 18 months in the modified intention-to-treat set (N = 1024). RESULTS: Severe SA was detected in 31.1% (172 of 553). A higher incidence of significant AF was reported in patients with severe SA than in patients with nonsevere SA (25.0% vs 13.9%; difference 11.1%; 95% confidence interval 3.7%-18.4%; P = .002). Significant AF increased with time in both groups, but at a faster rate in the severe SA group. No intergroup difference in the overall rate of major serious adverse events was observed (P = .065). CONCLUSION: SA screening over 12 months identified severe SA in almost one-third of unselected patients fitted with pacemakers. Severe SA was associated with a higher incidence of significant AF.

Cardiac contractility modulation treatment in patients with symptomatic heart failure despite optimal medical therapy and cardiac resynchronization therapy (CRT).

BACKGROUND: A significant proportion of patients receiving CRT are non-responders. We evaluated the efficacy of Cardiac Contractility Modulation in subjects with reduced LVEF who, despite cardiac resynchronization therapy (CRT), continued to experience clinically significant symptoms. METHODS: This was a multi-center, open label, treatment-only, feasibility study of 17 CRT non-responders who received CCM therapy. Changes in NYHA class, ejection fraction (EF), Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score, and exercise tolerance (6 minute walk test; 6MWT and peak VO2) were analyzed over 6 months. Mortality and hospitalization rates were determined. RESULTS: Patients (82% male) were 69.4 ±â€¯9.6 years of age with baseline EF = 22.8 ±â€¯6.5%. Among primary endpoints, peak VO2 increased 1.1 ±â€¯1.6 ml/kg/min (p = 0.03) and MLWHFQ improved (-16 ±â€¯16 points; p < 0.01). Mean NYHA class improved (-0.33 ±â€¯0.49; p = 0.02), 6MWT increased (52 ±â€¯60 m; p < 0.01), while EF trended up (2.9 ±â€¯5.8%; p = 0.08) at 6 months. During the 6-month follow-up period, there were 18 hospitalizations in 9 subjects and 2 patients died. CONCLUSIONS: Patients with heart failure and reduced ejection fraction who remain moderately to severely symptomatic despite use of CRT, may benefit from CCM therapy with improvement in quality of life and exercise tolerance. A larger prospective study in this population is warranted.

Clinical Course of Dual-Chamber Implantable Cardioverter-Defibrillator Recipients followed by Cardiac Remote Monitoring: Insights from the LION Registry.

Patients receiving dual-chamber implantable cardioverter-defibrillator (DR-ICD) therapy are at risk of developing atrial arrhythmia because of the increased rate of ventricular pacing and the progression of heart failure. Remote monitoring (RM) may identify the patients at highest risk of adverse events such as atrial arrhythmias. A total of 283 patients with 91,632 remote transmissions during a 15-month follow-up (FU) period enrolled in the LION registry were analysed. The parameters retrieved included the pacing mode, lower rate limit, percentage of atrial (%AP) and ventricular pacing (%VP), and percentage of atrial arrhythmia burden (%AB). In 92.7% of patients, the devices were initially programmed in DDD(R) or DDI(R), with changes of the pacing mode in 19.3% only. The lower rate limit remained stable in 80.4% of patients. At the first transmission, 8.7% of patients suffered from RM-detected atrial arrhythmia, which reached 36% during FU. The %AP was not associated with increased AB (p = 0.67), but the %VP was different in patients developing RM-detected atrial arrhythmia (26.9% vs. 13.7%, p < 0.00001). The %VP increased in 105 patients (significance level of α = 0.05), and 11 patients crossed the border of 50% VP. The LION substudy supports the concept of using RM in a real-world DR-ICD population. Remote monitoring of DR-ICDs allows for the quantification of the course of the pacing parameters and AB. Based on these observations, device parameters can be adjusted and optimized.

First clinical evaluation of an atrial haemodynamic sensor lead for automatic optimization of cardiac resynchronization therapy.

AIMS: One option to improve cardiac resynchronization therapy (CRT) responder rates lies in the optimization of pacing intervals. A haemodynamic sensor embedded in the SonRtip atrial lead measures cardiac contractility and provides a systematic automatic atrioventricular and interventricular delays optimization. This multi-centre study evaluated the safety and performance of the lead, up to 1 year. METHODS AND RESULTS: A total of 99 patients were implanted with the system composed of the lead and a CRT-Defibrillator device. Patients were followed at 1, 3, 6, and 12 months post-implant. The primary safety objective was to demonstrate that the atrial lead complication free rate was superior to 90% at 3-months follow-up visit. A lead handling questionnaire was filled by implanting investigators. Lead electrical performances and the performance of the system to compute AV and VV delays were evaluated at each study visit over 1 year. The complication free rate at 3 months post-implant was 99.0% [95%CI 94.5-100.0%], P < 0.001. Electrical performances of the lead were adequate whatever the atrial lead position and remained stable over the study period. The optimization algorithm was able to compute AV and VV delays in 97% of patients, during >75% of the weeks. CONCLUSION: The atrial lead is safe to implant and shows stable electrical performance over time. It therefore offers a promising tool for automatic CRT optimization to further improve responder rates to CRT.

Home monitoring of implantable cardioverter-defibrillators: interpretation reliability of the second-generation "IEGM Online" system.

AIMS: Intracardiac electrograms (IEGMs) are essential for the assessment of implantable cardioverter-defibrillator (ICD) function. The Biotronik Home Monitoring systems transmit an 'IEGM Online' that is shorter than the full-length programmer IEGM due to technical constrains. The aim of this study was to evaluate the accuracy of the physician's classification of the underlying rhythm based on the second-generation IEGM Online. METHODS AND RESULTS: In total, 1533 patients treated with single- and dual-chamber ICDs and cardiac resynchronization therapy defibrillators were enrolled at 67 investigational sites and followed for 15 months. The investigators classified the rhythm shown in IEGM Online as ventricular tachycardia, ventricular fibrillation, atrial fibrillation, other supraventricular tachyarrhythmia, oversensing due to lead failure, T-wave oversensing, or other rhythm. At the next in-office follow-up, the investigators classified independently the rhythm seen in the corresponding programmer IEGM. The two rhythm classifications were compared thereafter. Both IEGM Online and programmer IEGM were available in 2099 arrhythmic or oversensing events, of which 146 (7.0%) were classified as other rhythm or artefacts and were excluded as inconclusive or atypical. The remaining 1953 events, affecting 352 patients (23.0%), were classified correctly in 1803 cases (92.3%). The accuracy of rough rhythm classification as ventricular, supraventricular, or oversensing was 97.2%. CONCLUSION: The Lumax and IEGM Online HD Evaluation study demonstrates that remote IEGM analysis is reasonably accurate in a remote monitoring system that transmits shorter IEGM than the full-length programmer IEGM for the sake of frequent, fully automatic data transmission.

Noninvasive monitoring of stroke volume with resynchronization devices in patients with ischemic cardiomyopathy.

BACKGROUND: A novel method to estimate cardiac volumes based on impedance measurements using the leads of a resynchronization device has been developed. This study investigated the method in patients with ischemic cardiomyopathy and documented wall motion abnormalities. METHOD AND RESULTS: Fifteen postinfarction patients (age 68 ± 8 years, ejection fraction 27 ± 5%) with symptomatic heart failure and ≥ 1 akinetic or dyskinetic segment were included. During the implantation of a cardiac resynchronization therapy (CRT) device, acute impedance curves were recorded along with stroke volume determined by the arterial pulse contour method. In an overdrive protocol, the impedance parameter "stroke impedance" decreased in significant correlation with stroke volume in all patients. The median correlation coefficient between stroke volume and stroke impedance was 0.83 (interquartile range 0.70-0.89). Furthermore, the atrioventricular delay was optimized based on impedance and reference stroke volume. After optimization by the impedance method, it differed by 18 ± 15 ms from the figure after optimization by the invasive reference. Compared with a standard atrioventricular delay of 120 ms, stroke volume was improved by 8.6 ± 9.8% with the use of invasive optimization and by 6.4 ± 10.8% with the use of impedance-based optimization. CONCLUSIONS: In CRT patients with chronic infarction and wall motion abnormalities, impedance is a valid parameter to estimate stroke volume and to guide optimization of CRT timing.

Potential role of telemedical service centers in managing remote monitoring data transmitted daily by cardiac implantable electronic devices: results of the early detection of cardiovascular events in device patients with heart failure (detecT-Pilot) study.

OBJECTIVE: Implantable cardioverter-defibrillators (ICDs) alone or combined with cardiac resynchronization therapy (CRT-Ds) featuring automatic home monitoring (HM) function can be monitored remotely on a daily basis. Different ways of implementing HM into clinical routines are possible, with efficient patient management being the main objective. In this study, a concept using a telemedical service center (TmSC) to manage HM data was developed and investigated regarding patients' satisfaction, physicians' satisfaction, and alert filtering. SUBJECTS AND METHODS: Fifty-five ICD or CRT-D patients with symptomatic heart failure were enrolled. The TmSC received HM data, identified "actionable parameters" (APs) by following protocol-defined procedures, conducted structured patient interviews, and forwarded selected APs to the respective follow-up clinic. Satisfaction of patients and physicians with the TmSC was evaluated at the end of the study by purpose-designed questionnaires. RESULTS: During a mean follow-up of 402±200 days, 3,831 APs were identified and analyzed at the TmSC (5.28 per patient-month). Most APs were triggered by a pilot detection algorithm for worsening heart failure (2.80 per patient-month), followed by atrial tachyarrhythmia episodes (1.10 per patient-month) and ventricular pacing issues (0.87 per patient-month). The TmSC forwarded 682 APs (18% of all APs) to 10 study sites. Approximately 65% of physicians and patients deemed the TmSC improved patient care. CONCLUSIONS: The TmSC-based management concept was well accepted and appreciated by the majority of physicians and patients. It may be helpful in gaining symptomatic information on top of automatic HM data and in supporting smaller clinics in the follow-up of their device patients.

Dissimilar ventricular rhythms: implications for ICD therapy.

Sensing of left ventricular (LV) activity in some devices used for cardiac resynchronization therapy (CRT) was designed primarily to prevent the delivery of an LV stimulus into the LV vulnerable period. Such a sensing function of the LV channel is not universally available in contemporary CRT devices. Recordings of LV electrograms may provide special diagnostic data unavailable solely from the standard right ventricular electrogram and corresponding marker channel. We used the LV sensing function of Biotronik CRT defibrillators to find 3 cases of dissimilar ventricular rhythms or tachyarrhythmias. Such arrhythmias are potentially important because concomitant slower right ventricular activity may prevent or delay implantable cardioverter-defibrillator therapy for a life-threatening situation involving a faster and more serious LV tachyarrhythmia. Dissimilar ventricular rhythms may not be rare and may account for cases of unexplained sudden death with a normally functioning implantable cardioverter-defibrillator and no recorded terminal arrhythmia.

Potential value of automated daily screening of cardiac resynchronization therapy defibrillator diagnostics for prediction of major cardiovascular events: results from Home-CARE (Home Monitoring in Cardiac Resynchronization Therapy) study.

AIM: To investigate whether diagnostic data from implanted cardiac resynchronization therapy defibrillators (CRT-Ds) retrieved automatically at 24 h intervals via a Home Monitoring function can enable dynamic prediction of cardiovascular hospitalization and death. METHODS AND RESULTS: Three hundred and seventy-seven heart failure patients received CRT-Ds with Home Monitoring option. Data on all deaths and hospitalizations due to cardiovascular reasons and Home Monitoring data were collected prospectively during 1-year follow-up to develop a predictive algorithm with a predefined specificity of 99.5%. Seven parameters were included in the algorithm: mean heart rate over 24 h, heart rate at rest, patient activity, frequency of ventricular extrasystoles, atrial-atrial intervals (heart rate variability), right ventricular pacing impedance, and painless shock impedance. The algorithm was developed using a 25-day monitoring window ending 3 days before hospitalization or death. While the retrospective sensitivities of the individual parameters ranged from 23.6 to 50.0%, the combination of all parameters was 65.4% sensitive in detecting cardiovascular hospitalizations and deaths with 99.5% specificity (corresponding to 1.83 false-positive detections per patient-year of follow-up). The estimated relative risk of an event was 7.15-fold higher after a positive predictor finding than after a negative predictor finding. CONCLUSION: We developed an automated algorithm for dynamic prediction of cardiovascular events in patients treated with CRT-D devices capable of daily transmission of their diagnostic data via Home Monitoring. This tool may increase patients' quality of life and reduce morbidity, mortality, and health economic burden, it now warrants prospective studies. ClinicalTrials.gov NCT00376116.

Are autoantibodies against the beta1-adrenergic receptor markers for dilated cardiomyopathy?

BACKGROUND: Dilated cardiomyopathy (DCM) is one of the leading causes of heart failure in the western world but there is still no specific and early diagnosis available. Besides a genetic predisposition and viral infections, autoimmune reactions play an important role in the pathogenesis of DCM. The beta1-adrenergic receptor (beta1-AR) has been described as the major target structure in autoimmune DCM. METHODS: In this study a recombinant GST-beta1-AR fusion protein comprising the second extracellular loop was generated as a target for the analysis of autoantibodies in sera from 115 patients with different heart failure diseases (41 DCM, 30 non-ischemic secondary cardiomyopathy [NISCM], 44 coronary artery disease [CAD]). Sera were collected from a non-selected population of heart failure patients in consecutive order. RESULTS: Autoantibodies against the beta1-AR were detected in 37% of DCM, 30% of NISCM, and 36% of CAD patients but none of the controls were positive. Furthermore, our data show that cardiomyopathy patients with anti-beta1-AR antibodies are younger (54 years vs. 61 years [DCM], 53 years vs. 56 years [NISCM], 61 years vs. 61 years [CAD]. Regardless of diagnosis antibody-positive patients had lower EF levels (29% vs. 32%, p = 0.0001 [DCM]; 23% vs. 25%, p < 0.0001 [NISCM]; 23% vs. 25%, p < 0.0001 [CAD]) than the antibody-negative counterparts but, nevertheless, also lower NT-proBNP levels compared to antibody negative patients (567 pg/mL vs. 1296 pg/mL, p = 0.0005 [DCM]; 224 pg/mL vs. 1135 pg/mL, p = 0.0002 [NISCM]; 605 pg/mL vs. 940 pg/mL, p = 0.0005 [CAD]). CONCLUSIONS: We conclude that DCM patients should be further characterized and differentiated by the detection of autoantibodies against beta1-AR. Autoimmune DCM patients are younger compared with their non-autoimmune counterparts, possibly due to the autoimmune trigger of the disease or reflecting an early stage of the disease. Surprisingly, the autoimmune patients have worse clinical manifestations but show less excessive NT-proBNP levels. It is not clear yet, though, whether these autoantibodies have a direct impact on the NT-proBNP levels. Whether or not these data are a consequence of pathogenic antibodies has to be elucidated in further studies.