Hemodynamic monitoring by intracardiac impedance measured by cardiac resynchronization defibrillators: Evaluation in a controlled clinical setting (BIO.Detect HF II study).

BACKGROUND: In patients with cardiac resynchronization therapy defibrillators (CRT-Ds), intracardiac impedance measured by dedicated CRT-D software may be used to monitor hemodynamic changes. We investigated the relationship of hemodynamic parameters assessed by intracardiac impedance and by echocardiography in a controlled clinical setting. METHODS: The study enrolled 68 patients (mean age, 66 ± 9 years; 74% males) at 12 investigational sites. The patients had an indication for CRT-D implantation, New York Heart Association class II/III symptoms, left ventricular ejection fraction 15%-35%, and a QRS duration ≥150 ms. Two months after a CRT-D implantation, hemodynamic changes were provoked by overdrive pacing. Intracardiac impedance was recorded at rest and at four pacing rates ranging from 10 to 40 beats/min above the resting rate. In parallel, echocardiography measurements were performed. We hypothesized that a mean intra-individual correlation coefficient (rmean) between stroke impedance (difference between end-systolic and end-diastolic intracardiac impedance) measured by CRT-D and the aortic velocity time integral (i.e., stroke volume) determined by echocardiography would be significantly larger than 0.65. RESULTS: The hypothesis was evaluated in 40 patients with complete data sets. The rmean was 0.797, with a lower confidence interval bound of 0.709. The study hypothesis was met (p = 0.007). A stepwise reduction of stroke impedance and stroke volume was observed with increasing heart rate. CONCLUSIONS: Intracardiac impedance measured by implanted CRT-Ds correlated well with the aortic velocity time integral (stroke volume) determined by echocardiography. The impedance measurements bear potential and are readily available technically, not requiring implantation of additional material beyond standard CRT-D system.

Fluid status telemedicine alerts for heart failure: a randomized controlled trial.

AIMS: Hospital admissions are frequently preceded by increased pulmonary congestion in heart failure (HF) patients. This study evaluated whether early automated fluid status alert notification via telemedicine improves outcome in HF patients. METHODS AND RESULTS: Patients recently implanted with an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy were eligible if one of three conditions was met: prior HF hospitalization, recent diuretic treatment, or recent brain natriuretic peptide increase. Eligible patients were randomized (1:1) to have fluid status alerts automatically transmitted as inaudible text message alerts to the responsible physician or to receive standard care (no alerts). In the intervention arm, following a telemedicine alert, a protocol-specified algorithm with remote review of device data and telephone contact was prescribed to assess symptoms and initiate treatment. The primary endpoint was a composite of all-cause death and cardiovascular hospitalization. We followed 1002 patients for an average of 1.9 years. The primary endpoint occurred in 227 patients (45.0%) in the intervention arm and 239 patients (48.1%) in the control arm [hazard ratio, HR, 0.87; 95% confidence interval (CI), 0.72-1.04; P = 0.13]. There were 59 (11.7%) deaths in the intervention arm and 63 (12.7%) in the control arm (HR, 0.89; 95% CI, 0.62-1.28; P = 0.52). Twenty-four per cent of alerts were not transmitted and 30% were followed by a medical intervention. CONCLUSION: Among ICD patients with advanced HF, fluid status telemedicine alerts did not significantly improve outcomes. Adherence to treatment protocols by physicians and patients might be challenge for further developments in the telemedicine field.

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.

Cardiac resynchronization therapy improves psycho-cognitive performance in patients with heart failure.

BACKGROUND: Reduced cognitive performance and high prevalence of depression have been reported in patients with congestive heart failure (CHF) and severe left ventricular dysfunction. However, effects of contemporary device therapy on cognitive performance and depression symptoms have not been studied thoroughly. METHODS: Seventy-four consecutive CHF patients-45 receiving a biventricular defibrillator (CRT-D) and 29 receiving an implantable single or dual-chamber defibrillator (ICD) as a control group-were enrolled in this investigator-initiated, prospective, controlled, and investigator-blinded study. A set of neuropsychological tests (mini-mental state examination, DemTect, age-concentration test, and Beck depression inventory) was performed before, at 3 and at 6 months after device implantation. RESULTS: DemTect-score improved significantly (F = 7.8; P = 0.007) after CRT-D-implantation compared with ICD. Age-concentration test revealed better concentration ability after CRT-D-implantation (F = 8.3; P = 0.005) compared with ICD. Under CRT-D mini-mental state examination showed a significant improvement (F = 4.2; P = 0.043). CRT with defibrillator therapy also improved depression revealed by beck depression inventory (F = 14.7; P< 0.001) compared with ICD. CONCLUSION: This prospective study is the first to demonstrate psycho-cognitive improvement by resynchronization therapy in CHF patients with severe left ventricular dysfunction. In contrast to ICD therapy, the beneficial effect of CRT-D on psycho-cognitive performance might be attributed to improved cardiac function and haemodynamics.

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.

Effectiveness and Reliability of Selected Site Pacing for Avoidance of Phrenic Nerve Stimulation in CRT Patients with Quadripolar LV Leads: The EffaceQ Study.

BACKGROUND: Cardiac resynchronization therapy (CRT) relies on sufficient left ventricular (LV) pacing with safety margin to phrenic nerve stimulation (PNS). Previous studies introduced LV vector reprogramming in bipolar coronary sinus leads to optimize LV pacing and avoid PNS. We investigated the efficacy and reliability of quadripolar leads in CRT. METHODS: The EffaceQ study enrolled 344 patients with de novo CRT implantation with a quadripolar LV lead in an observational, prospective multicenter study. The study was powered to demonstrate that in at least 90% of patients with an implanted quadripolar LV lead, a viable LV pacing configuration (LVPC) is available (primary end point: LV pacing threshold ≤2.5 V/0.5 ms, sufficient PNS margin). RESULTS: Quadripolar leads were successfully implanted in 96% of patients. A total of 278 of 299 (93.0%) patients with complete data met the criteria for viable LVPC. With the use of traditional LVPCs, a viable LVPC would have been available (268 of 299 patients; P = 0.002) in significantly fewer patients (89.6%). In any LVPC, PNS was inducible in 65.0% of patients and 22.6% of patients reported PNS during ambulatory 3-month follow-up. LVPC reprogramming was performed in 49.8% of patients. PNS inducibility decreased from distal to proximal electrodes, whereas LV pacing thresholds increased from distal to proximal. At prehospital discharge, 5.9 ± 2.8 viable LVPCs were observed, stable during follow-up. The quadripolar electrode offered significantly more LVPC for LV optimization and PNS avoidance. CONCLUSION: Quadripolar LV leads yield high numbers of patients with viable LVPCs and alternatives for noninvasive repositioning of LV pacing.

Clinical relevance of slow ventricular tachycardia in heart failure patients with primary prophylactic implantable cardioverter defibrillator indication.

AIMS: Implantable cardioverter defibrillators (ICDs) have shown to reduce all-cause mortality in heart failure patients. In SCD-HeFT study, ICDs were programmed with a detection zone of ≥ 187 b.p.m. Thus, the incidence and clinical significance of slower ventricular tachycardias (VTs) in these patients remains largely unknown, though clinically important for device selection, programming, and follow-up. METHODS AND RESULTS: We prospectively studied symptomatic heart failure patients with an indication for a primary prophylactic ICD with or without concomitant resynchronization therapy according to SCD-HeFT inclusion criteria. Devices were programmed to an additional monitor zone for slow VTs at heart rates 130-186 b.p.m. Two hundred consecutive patients (86% male) were followed for a mean of 509 ± 308 days. One hundred and thirty-seven patients (68.5%) were New York Heart Association class III, 75 patients (37.5%) were on cardiac resynchronization therapy, and 124 (62%) had ischaemic cardiomyopathy. We observed 473 VT episodes in 36 patients (18%) and 131 ventricular fibrillation episodes in 30 patients (15%). Ventricular tachycardia overall occurred in 40 patients (20%). The incidence of slow VTs was low in only 12 patients (6%). No patient with slow VT suffered from syncope, palpitation, or decompensation leading to hospitalization. We did not find any reliable predictor for increased long-term risk of slow VTs. CONCLUSION: Incidence of slow VTs in a typical heart failure population with primary prophylactic ICD-implantation ± resynchronization therapy is very low. Slow VTs detected in the ICD monitor zone remained clinically asymptomatic. Thus, single chamber and atriobiventricular ICDs with a VT/ventricular fibrillation zone of ≥ 187 b.p.m. and one burst before shock delivery might be sufficient and pragmatic for the vast majority of these patients.

Impedance-based remote monitoring in patients with heart failure and concomitant chronic kidney disease.

AIMS: Remote monitoring (RM) of thoracic impedance represents an early marker of pulmonary congestion in heart failure (HF). Chronic kidney disease (CKD) may promote fluid overload in HF patients. We investigated whether concomitant CKD affected the efficacy of impedance-based RM in the OptiLink HF trial. METHODS AND RESULTS: Among HF patients included in the OptiLink HF trial, time to the first cardiovascular hospitalization and all-cause death according to the presence of concomitant CKD was analysed. CKD was defined as GFR < 60 mL/min/1.73 m2 at enrolment. Of the 1002 patients included in OptiLink HF, 326 patients (33%) had HF with concomitant CKD. The presence of CKD increased transmission of telemedical alerts (median of 2 (1-5) vs. 1 (0-3); P = 0.012). Appropriate contacting after alert transmission was equally low in patients with and without CKD (57% vs. 59%, P = 0.593). The risk of the primary endpoint was higher in patients with CKD compared with patients without CKD (hazard ratio (HR), 1.62 [95% confidence interval (CI), 1.16-2.28]; P = 0.005). Impedance-based RM independently reduced primary events in HF patients with preserved renal function, but not in those with CKD (HR 0.68 [95% CI, 0.52-0.89]; P = 0.006). CONCLUSIONS: The presence of CKD in HF patients led to a higher number of telemedical alert transmissions and increased the risk of the primary endpoint. Inappropriate handling of alert transmission was commonly observed in patients with chronic HF and CKD. Guidance of HF management by impedance-based RM significantly decreased primary event rates in patients without CKD, but not in patients with CKD.

Ablation of typical right atrial flutter in patients with pulmonary hypertension.

BACKGROUND: RF ablation for cavotricuspid isthmus (CTI) dependent flutter is an established therapy. Right atrial hypertrophy and enlargement are associated with the occurrence of cavotricuspid isthmus dependent flutter. Therefore, patients with pulmonary hypertension (PAH) are prone to atrial arrhythmias like cavotricuspid isthmus dependent flutter. However, the influence of PAH on typical atrial flutter ablation procedure has not been systematically examined. METHODS: In a retrospective single-centre analysis data of patients undergoing an ablation procedure for cavotricuspid isthmus dependent flutter between January 2007 and October 2009 at Hannover Medical School, Germany were analysed. Only procedures performed by experienced electrophysiologists with an 8mm RF-ablation catheter were included. Data for 196 patients were analysed. Thirty-eight patients were identified with PAH and were compared to 158 patients without PAH for procedural ablation parameters, procedure time, ablation time, ablation points and fluoroscopy time. RESULTS: A bidirectional block of the CTI was achieved in all patients. Patients with severe PAH had a significantly longer procedure time (78±40 min vs. 62±29 min; p=0.033), total ablation time (20±11 min vs. 15±9 min; p=0.02) and more ablation lesions (26±16 vs. 19±12; p=0.018) as compared to patients without PAH. CONCLUSION: Cavotricuspid isthmus dependent flutter ablation in patients with PAH is associated with longer procedure duration and a greater amount of cumulative tissue ablation needed to achieve bidirectional block of the CTI compared to patients without pulmonary hypertension.

Depressive Symptoms and Quality of Life in Patients With Heart Failure and an Implantable Cardioverter-Defibrillator.

Background: Heart failure (HF) is associated with development of depressive symptoms and reduced quality of life (QoL). Patients with HF and an implantable cardioverter-defibrillator (ICD) were evaluated regarding depressive symptoms and QoL. Methods: The present study included 446 patients with HF and an ICD. Depressive symptoms were assessed using the Patient Health Questionnaire 9 (PHQ-9), QoL was evaluated using the Minnesota Living with Heart Failure Questionnaire (MLHFQ). Functional ability and exercise tolerance were assessed at inclusion and after 6 months with help of the 6-min walking test (6MWT). Results: Patients included in the study had a mean age of 65.8 years and were predominantly male (83.6%), with mostly ischemic (n = 277; 62.1%) or dilated (n = 150; 33.6%) cardiomyopathy. One hundred ninety-three (43.2%) patients had depressive symptoms, of whom 75 patients (16.8%) were classified as moderate to severe depression according to the PHQ-9 at baseline. Depressive symptoms were associated with low QoL independent of NYHA functional class. High NYHA functional class, high PHQ-9 score, age and body mass index (BMI) were associated with a lower 6MWT at enrollment, while depressive symptoms (expressed as higher PHQ-9 score) and age were associated with a lower 6MWT after 6 months. Patients with history of smoking and a higher BMI showed higher PHQ-9 scores after 6 months. Patients under antidepressant medication showed improved PHQ-9 score after 6 months, indicating controlled/treated depression. However, patients with low QoL at inclusion remained with low QoL after 6 months. Conclusion: Depressive symptoms correlate with low QoL and lower long-term functional status in patients with HF and an ICD. Depressive symptoms are associated with smoking and obesity, which themselves are risk factors for a poor prognosis in HF. Only a small fraction of patients with HF and ICD showing depressive symptoms receives appropriate treatment. Assessing depressive symptoms and lifestyle factors should be part of a multimodal treatment plan in patients with HF and an ICD.

Differences in management of telemedicine alerts on weekdays and public holidays: Results from the OptiLink heart failure trial.

BACKGROUND: In the OptiLink heart failure study, timely and appropriate reactions to telemedicine alerts improved clinical outcomes in heart failure patients. This analysis investigates the relation between the weekday of alert transmission and the subsequent patient contact. METHODS: In patients enrolled in the intervention arm of the OptiLink heart failure study (n = 505, age 66.1 ± 10.1, 77.2% male, left-ventricular ejection fraction 26.7% ± 6.1%), fluid index threshold crossing alerts were analysed according to the weekday of the transmission. Transmissions on Mondays-Thursdays were categorized as TD1, Fridays-Sundays as well as public holidays as TD2. RESULTS: Of 1365 transmitted alerts, 867 (63.5%) were categorized as TD1 and 498 (36.5%) as TD2. Same day telephone contacts were more frequent in TD1 (46.2%) than in TD2 (18.3%; p < 0.001). Accordingly, the median time to contact was significantly longer in TD2 compared with TD1 (2(1-3) vs 0(0-1) days; p < 0.001). Rates of no telephone contact were no different between the groups (12.1% vs 12.4%; p = 0.866). Although signs of worsening heart failure were prevalent in 32.4% in TD1 versus 32.1% in TD2 (p = 0.996), initiation of a pharmacological intervention occurred more likely in TD1 compared with TD2 (27.9% vs 22.9%; p = 0.041). No differences existed concerning hospitalization for heart failure within 30 days after alert transmission (3.9% vs 3.4%; p = 0.636). CONCLUSION: Alert transmissions during weekends and public holidays were less likely associated with timely patient contacts and initiation of pharmacological interventions than during the week. Telemedical centres providing 24/7 remote monitoring service and specific education programmes for physicians might help to optimize patient care.

Remote Monitoring With Appropriate Reaction to Alerts Was Associated With Improved Outcomes in Chronic Heart Failure: Results From the OptiLink HF Study.

BACKGROUND: Impedance-based remote monitoring (RM) failed to reduce clinical events in the OptiLink heart failure (HF) trial. However, rates of alert-driven interventions triggered by intrathoracic fluid index threshold crossings (FTC) were low indicating physicians' inappropriate reactions to alerts. METHODS: We separated appropriate from inappropriate contacts to FTC transmissions in the OptiLink HF trial (Optimization of Heart Failure Management Using OptiVol™ Fluid Status Monitoring and CareLink™). Appropriate contacts had to meet the following criteria: (1) initial telephone contact within 2 working days after FTC transmission, (2) follow-up contacts according to study protocol, and (3) medical intervention initiated after FTC due to cardiac decompensation. We compared time to cardiovascular death or HF hospitalization between RM patients contacted appropriately or inappropriately and patients with usual care. RESULTS: In the RM group, at least one FTC alert was transmitted in 356 patients (70.5%; n=505). Of note, only 55.5% (n=758) of all transmitted FTCs (n=1365) were followed by an appropriate contact. While 113 patients (31.7%; n=356) have been contacted appropriately after every FTC, in 243 patients (68.3%; n=356) at least one FTC was not responded by an appropriate contact. Compared with usual care, RM with appropriate contacts to FTC alerts independently reduced the risk of the primary end point (hazard ratio, 0.61 [95% CI, 0.39-0.95]; P=0.027). CONCLUSIONS: RM appropriate reactions to FTC alerts are associated with significantly improved clinical outcomes in patients with advanced HF and implantable cardioverter-defibrillators.

Treatment of patients with recurrent or persistent infection of cardiac implantable electronic devices.

BACKGROUND: Increasing rates of bacterial infections in device therapy of cardiac rhythm disturbances pose a clinical problem. Radical surgical treatment yields the best long-term results but is frequently preceded by conservative treatment or limited surgical procedures leading to an unnecessary long treatment course. Recurrence/persistence of infection then potentially poses an even more serious clinical problem. METHODS AND RESULTS: A total of 192 consecutive explantation procedures were performed for cardiac implantable electronic device (CIED) infections over a 10 year period. Forty-nine cases followed recurrence of infection subsequent to prior surgical treatment for device infection. Differences in patient/disease characteristics and outcome were looked for in recurrent as compared to primary infections (referral mode) to identify a potential requirement for adjusting treatment in recurrence. With a minimum follow-up of 24 months, 98% eradication of infection was observed independent of referral mode. Differences between primary and recurrent infection essentially reflected the primary presenting clinical picture-chronic smouldering vs. acute systemic infection. Various parameters that follow from this differentiation are significantly different between the groups. There was however no difference in outcome in terms of mortality and rate of recurrence. In addition, the parameters of the extraction procedure did not differ considerably. CONCLUSION: Despite significant differences in baseline and disease characteristics between primary and recurrent CIED infection, a standardized radical protocol results in an equally high success rate in eradicating infection in both groups. Nevertheless, direct and un-delayed referral of patients with suspected CIED infection to specialized centres is recommended as it saves time for the patient.

A prospective experience with the lead integrity alert: new certainties and new uncertainties.

Lead fracture is one of the major complications in implantable cardioverter defibrillator (ICD) therapy often leading to a series of inadequate shocks and thus greatly impairing quality of life of patients. The novel lead integrity alert algorithm by Medtronic (Medtronic Inc., Minneapolis, MN, USA) is addressing this problem. We report a case of a lead failure being correctly predicted by shifting lead impedances about 4 weeks before the first episode of oversensing. Additionally, our case illustrates the new problem of how to clinically handle a patient with a highly probable, but not completely certain, ICD-lead failure.

Arrhythmia susceptibility in mice after therapy with beta-catenin-transduced hematopoietic progenitor cells after myocardial ischemia/reperfusion.

BACKGROUND: Hematopoietic progenitor cells (HPCs) can improve cardiac function after myocardial infarction. However, occurrence of arrhythmias is a potential limitation of cell therapy. In this study, we investigated the cardiac electrophysiological properties of ex vivo expanded HPCs, generated by beta-catenin gene transfer, after transcoronary delivery in a murine model of ischemia/reperfusion (I/R) injury. METHODS AND RESULTS: To assess arrhythmia inducibility of ex vivo expanded HPCs, mice were subjected to I/R and assigned to sham operation (n = 8), I/R (n = 21) and HPC (n = 15) treatment. Six weeks later, mice were subjected to long-term electrocardiogram recording and in vivo transvenous electrophysiological study. After I/R, mice showed a significant prolongation of conduction and repolarization compared with sham-operated mice. There was a marked increase in ventricular ectopic activity in infarcted mice as compared with sham-operated mice. Cardiac electrophysiological parameters and ventricular ectopic activity were not altered in mice treated with HPCs in comparison with control I/R mice. CONCLUSION: Transcoronary delivery of genetically ex vivoexpanded HPCs did not alter the electrophysiological properties in mice after I/R. Therefore, ex vivo beta-catenin-mediated HPC expansion may represent an attractive therapeutic option for cell transplantation treatment of myocardial infarction without electrophysiological side effects.

Left atrial substrate ablation in addition to pulmonary vein isolation in paroxysmal atrial fibrillation using a large 28-mm cryoballoon.

We report a case of successful isolation of all pulmonary veins (PV) for symptomatic paroxysmal atrial fibrillation using a 23-mm cryoballoon with continued paroxysmal atrial fibrillation during a 3-month follow-up. Left atrial-to-PV-junction ablation was then performed 3 months after the first procedure using a larger 28-mm balloon despite unrecovered isolation of all four PV, thereby curing symptomatic atrial fibrillation in this case.

Morphology of current of injury does not predict long term active fixation ICD lead performance.

BACKGROUND: Currents of injury (COI) have been associated with improved lead performance during perioperative measurements in pacemaker and ICD implants. Their relevance on long term lead stability remains unclear. METHODS: Unipolar signals were recorded immediately after active fixation ICD lead positioning, blinded to the implanting surgeon. Signals were assigned to prespecified COI types by two independent investigators. Sensing, pacing as well as changes requiring surgical intervention were prospectively investigated for 3 months. RESULTS: 105 consecutive ICD lead implants were studied. All could be assigned to a particular COI with 48 type 1, 43 type 2 and 14 type 3 signals. Pacing impedance at implant was 703.8+/-151.6 Ohm with a significant COI independent drop within the first week. Sensing was 10.6mV+/- 3.7mV and pacing threshold at implant was 0.8+/-0.3mV at 0.5ms at implant. There was no significant difference between COI groups at implant and during a 3 months follow up regarding sensing, pacing nor surgical revisions. CONCLUSIONS: Three distinct patterns of unipolar endocardial potentials were observed in active fixation ICD lead implant, but COI morphology did not predict lead performance after 3 months.

Implant-based multi-parameter telemonitoring of patients with heart failure and a defibrillator with vs. without cardiac resynchronization therapy option: a subanalysis of the IN-TIME trial.

AIMS: In the IN-TIME trial, automatic daily implant-based multiparameter telemonitoring significantly improved clinical outcomes in patients with chronic systolic heart failure and implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D). We compared IN-TIME results for ICD and CRT-D subgroups. METHODS: Patients with LVEF ≤ 35%, NYHA class II/III, optimized drug treatment, no permanent atrial fibrillation, and a dual-chamber ICD (n = 274) or CRT-D (n = 390) were randomized 1:1 to telemonitoring or no telemonitoring for 12 months. Primary outcome measure was a composite clinical score, classified as worsened if the patient died or had heart failure-related hospitalization, worse NYHA class, or a worse self-reported overall condition. RESULTS: The prevalence of worsened score at study end was higher in CRT-D than ICD patients (26.4% vs. 18.2%; P = 0.014), as was mortality (7.4% vs. 4.1%; P = 0.069). With telemonitoring, odds ratios (OR) for worsened score and hazard ratios (HR) for mortality were similar in the ICD [OR = 0.55 (P = 0.058), HR = 0.39 (P = 0.17)] and CRT-D [OR = 0.68 (P = 0.10), HR = 0.35 (P = 0.018)] subgroups (insignificant interaction, P = 0.58-0.91). CONCLUSION: Daily multiparameter telemonitoring has a potential to reduce clinical endpoints in patients with chronic systolic heart failure both in ICD and CRT-D subgroups. The absolute benefit seems to be higher in higher-risk populations with worse prognosis.

Effect of restoring sinus rhythm on sleep apnea in patients with atrial fibrillation or flutter.

Sleep apnea (SA) is more prevalent in patients with atrial fibrillation (AF), but the impact of cardioversion on disordered breathing is unknown. Thus, we investigated the influence of restoring sinus rhythm in patients with AF and atrial flutter (AFlut) on SA. The 16 patients (mean age 63.1 +/- 11.2) with AF (n = 6) or AFlut (n = 10) and SA (apnea-hypopnea index >10) received cardioversion or ablation of cavotricuspid isthmus. We compared the severity of SA by sleep polygraphy under AF/Aflut with the first night after restoring sinus rhythm and after 4 weeks. Apnea-hypopnea index before and immediately after restoring sinus rhythm was similar (31.7 +/- 13.2 vs 30.1 +/- 15.7, p = NS) despite a significantly reduced heart rate (86.7 +/- 26.5 vs 67.8 +/- 11.9 beats/min, p <0.02). After 4 weeks, apnea-hypopnea index remained unchanged (38.1 +/- 18.1, p = NS) although heart rate was further reduced (61.8 +/- 8.8 beats/min, p <0.003). In our study, SA could not be improved by cardioversion of AF/AFlut. Therefore, although it is well known that SA leads to AF, eliminating AF does not cure or improve SA. In conclusion, our study shows that AF should be regarded more as an innocent bystander than a causative or aggravating condition in SA.

Right ventricular pacing is an independent predictor for ventricular tachycardia/ventricular fibrillation occurrence and heart failure events in patients with an implantable cardioverter-defibrillator.

AIMS: There is increasing evidence that right ventricular (RV) pacing may have detrimental effects by increasing morbidity and mortality for heart failure in implantable cardioverter-defibrillator (ICD) patients. In this study we prospectively tested the hypothesis that cumulative RV pacing increases ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence (primary endpoint) and hospitalization and mortality for heart failure (secondary endpoint) in a predominantly secondary prophylactic ICD patient population. METHODS AND RESULTS: Two hundred and fifty patients were divided into two groups according to the median of cumulative RV pacing (< or =2 vs. >2%) and prospectively followed-up for occurrence of primary and secondary endpoints for 18 +/- 4 months. Established predictors for VT/VF occurrence and heart failure events such as age, left ventricular ejection fraction (EF), QRS duration, history of atrial fibrillation, and NT-proBNP were collected at enrollment. Multivariate Cox regression analysis revealed that cumulative RV pacing > 2% and EF < 40% were independent predictors for VT/VF occurrence and heart failure events. Kaplan-Meier analysis showed that patients with >2% cumulative RV pacing more frequently suffered from VT/VF occurrence and heart failure hospitalization. CONCLUSION: Cumulative RV pacing > 2% and EF < 40% are independent predictors for VT/VF occurrence and mortality and hospitalization for heart failure in predominantly secondary prophylactic ICD patients. Our data show that algorithms capable of reducing cumulative RV pacing should be used more frequently in clinical practice.