Novel Implantable Cardioverter Defibrillator Programming With High Rate Cut-Off, Long Detection Intervals and Multiple Anti-Tachycardia Pacing Reduces Mortality.

BACKGROUND: Implantable cardioverter defibrillator (ICD) therapies, even when appropriate, are associated with increased risk. Therapy-reducing strategies have been shown to reduce the mortality rate.Methods and Results:In total, 895 patients with ICD and cardiac resynchronization therapy with defibrillation function (CRT-D) were included in the study; of these, 506 (57%) patients undergoing secondary prevention were included. Devices implanted before May 2014 were programmed according to conventional programming (CP), the others according to our novel programming (NP) with high rate cut-off, longer detection intervals and 4-6 anti-tachycardia pacing (ATP) trains in the ventricular tachycardia (VT) zone. Time-to-first-event for mortality, appropriate and inappropriate therapies were analyzed. Follow-up time was 24.0 months (IQR 13.0-24.0 months). There was a significant reduction in mortality rate (11.4% vs. 25.4%, P<0.001) and in the rate of appropriate (18.8% vs. 42.2%, P<0.001) and inappropriate therapies (5.2% vs. 18.0%, P<0.001) with NP according to Kaplan-Meier analyses. In multivariate analysis, NP (hazard ratio [HR]=0.35; P<0.001), chronic kidney disease (HR=1.55), reduced ejection fraction (EF) (HR=1.35), secondary ICD indication (HR=2.35) and age at implantation (HR=1.02) were associated with mortality reduction. NP was also associated with significant reduction in the rate of appropriate and inappropriate therapies. These results were consistent after stratification for primary and secondary prevention. CONCLUSIONS: Novel ICD programming reduced mortality and morbidity due to appropriate or inappropriate ICD therapies in secondary as well as in primary ICD indication.

Brain Natriuretic Peptide and Discovery of Atrial Fibrillation After Stroke: A Subanalysis of the Find-AFRANDOMISED Trial.

Background and Purpose- Diagnosing paroxysmal atrial fibrillation (pAF) can be challenging after acute ischemic stroke. Enhanced and prolonged Holter-ECG monitoring (EPM) improves the detection rate but is not feasible for all patients. We hypothesized that brain natriuretic peptide (BNP) may help to identify patients with stroke at high risk for pAF to select patients for EPM more effectively. Methods- Patients with acute cerebral ischemia ≥60 years presenting in sinus rhythm and without history of AF were included into a prospective, randomized multicenter study to receive either EPM (3× 10-day Holter-ECG) or usual stroke care diagnostic work-up. BNP plasma levels were measured on randomization and 3 months thereafter. Levels were compared between patients with and without pAF detected by means of EPM or usual care. Furthermore, the number needed to screen for EPM depending on BNP cut offs was calculated. Results- A total of 398 patients were analyzed. In 373 patients (93.7%), BNP was measured at baseline and in 275 patients (69.1%) after 3 months. pAF was found in 27 patients by means of EPM and in 9 patients by means of usual care (P=0.002). Median BNP was higher in patients with pAF as compared to patients without AF in both study arms at baseline (57.8 versus 28.3 pg/mL in the EPM arm, P=0.0003; 46.2 versus 27.7 pg/mL, P=0.28 in the control arm) and after 3 months (74.9 versus 31.3 pg/mL, P=0.012 in the EPM arm, 99.3 versus 26.3 pg/mL, P=0.02 in the control arm). Applying a cut off of 100 pg/mL, the number needed to screen was reduced from 18 by usual care to 3 by EPM. Conclusions- BNP measured early after ischemic stroke identifies a subgroup of patients with stroke at increased risk for AF, in whom EPM is particularly efficacious. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01855035.

High Predictive Value of Adenosine Provocation in Predicting Atrial Fibrillation Recurrence After Pulmonary Vein Isolation With Visually Guided Laser Balloon Compared With Radiofrequency Ablation.

BACKGROUND: We recently demonstrated that the acute reconnection rate detected with adenosine provocation test (APT) was significantly lower after pulmonary vein isolation (PVI) with visually guided laser balloon ablation (VGLB) than with RF ablation (RF). We evaluated the recurrence rate of atrial arrhythmias at 12 months after VGLB vs. RF and the significance of APT results for the outcome.Methods and Results:Fifty patients with paroxysmal AF were randomized to either RF or VGLB ablation in a 1 : 1 fashion. After PVI each PV underwent an APT. All patients underwent a 3-day Holter and clinical follow-up every 3 months. Significantly less PVs reconnected during APT in the VGLB-arm (10 PV (10.8%) vs. 29 PV (30.9%); P=0.001). Significantly less patients had a recurrence of atrial arrhythmia in the VGLB-arm (3 vs. 9; P=0.047). In the VGLB-arm no recurrence was seen in those patients with a negative APT (negative predictive value (NPV)=100%). Only 3 of the 8 patients with a positive APT in the VGLB-arm had a recurrence (positive PV (PPV)=37%). Recurrences in the RF-arm were seen in 3 patients with positive APT as well as in 6 patients with negative APT (PPV=18% and NPV=33%). CONCLUSIONS: There was significantly less recurrence of atrial arrhythmias at 12 months after PVI with VGLB. A negative APT after PVI with VGBL predicted freedom from AF with a very high NPV meaning that the high acute efficiency of the VGLB persisted long term.

A RAndomized Trial to compare the acute reconnection after pulmonary vein ISolation with Laser-BalloON versus radiofrequency Ablation: RATISBONA trial.

INTRODUCTION: Dormant conduction and acute reconnection in the pulmonary veins (PV) during a PV isolation can be detected by performing an adenosine provocation test (APT). Visually guided laser balloon ablation (VGLB) creates deep transmural lesions, thus causing less acute reconnection. This study compared the acute PV reconnection rate after isolation with VGLB or with RF using an APT. METHODS AND RESULTS: Patients with paroxysmal AF were randomized to PVI with the VGLB or RF ablation. Each PV underwent an APT at least 20 minutes after successful isolation with injection of 18 mg adenosine. Primary endpoint was the difference between the two ablation methods regarding acute PV reconnection rate detected with APT. A total of 50 patients were randomized into the study (25 VGLB). The basic characteristics and mean procedure time were not different between the two groups. Note that 96% of the 97 targeted PVs in the VGLB group and 98% of the 96 targeted PVs in the RF group could be isolated (P  =  0.41). APT was performed at similar times (after 28 minutes in VGLB-arm vs. after 31.5 minutes in RF-arm; P  =  0.12). Significantly less PVs were reconnected during APT in the VGLB group than in the RF group (10 PV [10.8%] vs. 29 PV [30.9%]; P  =  0.001). CONCLUSION: The acute PV reconnection rate is significantly less after PVI with VGBL than with RF. The clinical significance of this apparently better procedural efficiency of the VGBL ablation should be assessed with new randomized studies looking at AF recurrence.

Clinical value of different QRS-T angle expressions.

Aims: Increased spatial angle between QRS complex and T wave loop orientations has repeatedly been shown to predict cardiac risk. However, there is no consensus on the methods for the calculation of the angle. This study compared the reproducibility and predictive power of three most common ways of QRS-T angle assessment. Methods and results: Electrocardiograms of 352 healthy subjects, 941 survivors of acute myocardial infarction (MI), and 605 patients recorded prior to the implantation of automatic defibrillator [implantable cardioverter defibrillator (ICD)] were used to obtain QRS-T angle measurements by the maximum R to T (MRT), area R to T (ART), and total cosine R to T (TCRT) methods. The results were compared in terms of physiologic reproducibility and power to predict mortality in the cardiac patients during 5-year follow-up. Maximum R to T results were significantly less reproducible compared to the other two methods. Among both survivors of acute MI and ICD recipients, TCRT method was statistically significantly more powerful in predicting mortality during follow-up. Among the acute MI survivors, increased spatial QRS-T angle (TCRT assessment) was particularly powerful in predicting sudden cardiac death with the area under the receiver operator characteristic of 78% (90% confidence interval 63-90%). Among the ICD recipients, TCRT also predicted mortality significantly among patients with prolonged QRS complex duration when the spatial orientation of the QRS complex is poorly defined. Conclusion: The TCRT method for the assessment of spatial QRS-T angle appears to offer important advantages in comparison to other methods of measurement. This approach should be included in future clinical studies of the QRS-T angle. The TCRT method might also be a reasonable candidate for the standardization of the QRS-T angle assessment.

Sex difference in appropriate shocks but not mortality during long-term follow-up in patients with implantable cardioverter-defibrillators.

AIMS: Implantable cardioverter-defibrillators (ICDs) have been shown to improve survival, although a considerable number of patients never receive therapy. Implantable cardioverter-defibrillators are routinely implanted regardless of sex. There is continuing controversy whether major outcomes differ between men and women. METHODS AND RESULTS: In this retrospective single-centre study, 1151 consecutive patients (19% women) undergoing ICD implantation between 1998 and 2010 were followed for mortality and first appropriate ICD shock over 4.9 ± 2.7 years. Sex-related differences were investigated using multivariable Cox models adjusting for potential confounders. During follow-up, 318 patients died, a rate of 5.9% per year among men and 4.6% among women (uncorrected P = 0.08); 266 patients received a first appropriate ICD shock (6.3% per year among men vs. 3.6% among women, P = 0.002). After multivariate correction, independent predictors of all-cause mortality were age (hazard ratio, HR = 1.04 per year of age, 95% confidence interval (CI) [1.03-1.06], P < 0.001), left ventricular ejection fraction (HR = 0.98 per %, 95% CI [0.97-1.00], P = 0.025), renal function (HR = 0.99 per mL/min/1.73 m(2), 95% CI [0.99-1.00], P = 0.009), use of diuretics (HR = 1.81, 95% CI [1.29-2.54], P = 0.0023), peripheral arterial disease (HR = 2.21, 95% CI [1.62-3.00], P < 0.001), and chronic obstructive pulmonary disease (HR = 1.48, 95% CI [1.13-1.94], P = 0.029), but not sex. Female sex (HR = 0.51, 95% CI [0.33-0.81], P = 0.013), older age (HR = 0.98, 95% CI [0.97-0.99], P < 0.001), and primary prophylactic ICD indication (HR = 0.69, 95% CI [0.52-0.93], P = 0.043) were independent predictors for less appropriate shocks. CONCLUSION: Women receive 50% less appropriate shocks than men having similar mortality in this large single-centre population. These data may pertain to individually improved selection of defibrillator candidates using risk factors, e.g. sex as demonstrated in this study.

ICD risk stratification studies - EU-CERT-ICD and the European perspective.

BACKGROUND AND RATIONALE: In patients with ischemic or non-ischemic cardiomyopathy and impaired left ventricular ejection fraction, treatment with implantable cardioverter-defibrillator (ICD) has been shown to improve survival and guidelines recommend their use for primary prevention of sudden cardiac death. Experts disagree regarding the validity of decade-old trial results as the basis for this recommendation, therefore, reconsideration of prophylactic ICD treatment is needed. EU-CERT-ICD, DANISH-ICD AND DO-IT: In order to update the evidence on prophylactic ICD treatment, several prospective studies are underway in Europe. The prospective EU-CERT-ICD cohort study (NCT 02064192) is enrolling 2500 patients and compares patients undergoing first ICD implantation with controls with an earlier clinical decision to go without ICD implantation strictly unrelated to the study. The DANISH ICD study (NCT 00542945) has randomized 1000 patients with dilated cardiomyopathy and an LVEF ≤35% (1:1 ICD implantation vs. control). The prospective DO-IT multicenter registry will include 1500 ICD patients in multiple Dutch high-volume implanting centers. Due to the widespread use of ICD therapy, new randomized trials seem not straightforward to envisage in many countries. CONCLUSION: The above described ICD studies will provide additional evidence regarding the effectiveness of primary prophylactic ICDs in Europe and may have an impact on ICD treatment guidelines. They could also help to design randomized trials in low risk patients.

A randomized study of remote monitoring and fluid monitoring for the management of patients with implanted cardiac arrhythmia devices.

AIMS: Only limited comparative data exist on the benefits of fluid monitoring (FM) combined with remote monitoring (RM) regarding morbidity and mortality of heart failure (HF) patients. This prospective single-centre randomized pilot study aimed to estimate the influence of RM in combination with FM on HF hospitalizations as well as ventricular tachyarrhythmias and mortality. METHODS AND RESULTS: Patients with standard indication for implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy and defibrillator were implanted with devices capable of RM and FM, and were followed for 15 months. Subjects were randomly allocated to RM including OptiVol and predefined management of alerts (remote group), or standard in-office visits every 3 months (control group). A total of 176 patients (77% male; 66 ± 12 years; left ventricular ejection fraction (LVEF) 32 ± 11%; ischemic cardiomyopathy 50%; CRT device 50%; primary prevention 85%) were analysed. Cox proportional hazard analysis on the time to first HF-related hospitalization showed a hazard ratio of 1.23 [0.62-2.44] (P = 0.551) favouring the control group. In the remote group, 13 patients (15%) experienced ICD shocks vs. 10 patients (11%) in the control group (P = 0.512). The average time to first ICD shock was 212 ± 173 days in the remote arm and 212 ± 143 days in the control arm (P = 0.994). The Kaplan-Meier estimate of mortality after 1 year was 8.6% (eight deaths) in the remote group vs. 4.6% in the control group (six deaths; P = 0.502). CONCLUSION: In a single-centre randomized pilot study of RM in combination with FM, no significant influence on HF-related hospitalizations, ICD shocks, or mortality was found.

Unmasking the dormant pulmonary vein conduction with adenosine administration after pulmonary vein isolation with laser energy.

AIMS: The isolation of the pulmonary veins (PVs) is the mainstay of atrial fibrillation (AF) ablation, which with current ablation techniques can be achieved in almost all cases. Reconnection of PVs constitutes the most frequent cause of AF recurrence. Visually guided laser balloon ablation (VGLA) is a novel system with very high rate of persistence of pulmonary vein isolation (PVI) three months after the first procedure shown in preclinical and clinical studies. We aimed to determine the acute efficiency of the laser energy during PVI with the help of adenosine provocation. METHODS AND RESULTS: Twenty-six patients (19 male; mean age 64 ± 9 years) with symptomatic paroxysmal AF were included in the study. Pulmonary vein isolation was performed using the VGLA system. After successful PVI, we studied the effects of intravenous adenosine (18 mg) on activation of each PV at least 20 min after PVI. A total of 104 PVs were targeted. The balloon catheter could not be placed in two PVs. Of the remaining 102 PVs 99 (97% of the ablated PVs) could be successfully isolated. Adenosine was administered for each isolated PV in 25 patients. Only six PVs (6.7%) in five patients (20%) showed a PV reconnection during adenosine provocation. CONCLUSION: Pulmonary vein isolation with VGLA is a feasible technique for PVI with a very effective acute lesion formation. The clinical significance of this low reconnection rate has to be determined.

Finding atrial fibrillation in stroke patients: Randomized evaluation of enhanced and prolonged Holter monitoring--Find-AF(RANDOMISED) --rationale and design.

BACKGROUND: Detecting paroxysmal atrial fibrillation (AF) in patients with ischemic strokes presenting in sinus rhythm is challenging because episodes are often short, occur randomly, and are frequently asymptomatic. If AF is detected, recurrent thromboembolism can be prevented efficiently by oral anticoagulation. Numerous uncontrolled studies using various electrocardiogram (ECG) devices have established that prolonged ECG monitoring increases the yield of AF detection, but most established procedures are time-consuming and costly. The few randomized trials are mostly limited to cryptogenic strokes. The optimal method, duration, and patient selection remain unclear. Repeated prolonged continuous Holter ECG monitoring to detect paroxysmal AF within an unspecific stroke population may prove to be a widely applicable, effective secondary prevention strategy. STUDY DESIGN: Find-AFRANDOMISED is a randomized and controlled prospective multicenter trial. Four hundred patients 60 years or older with manifest (symptoms ≥24 hours or acute computed tomography/magnetic resonance imaging lesion) and acute (symptoms ≤7 days) ischemic strokes will be included at 4 certified stroke centers in Germany. Those with previously diagnosed AF/flutter, indications/contraindications for oral anticoagulation, or obvious causative blood vessel pathologies will be excluded. Patients will be randomized 1:1 to either enhanced and prolonged Holter ECG monitoring (10 days at baseline and after 3 and 6 months) or standard of care (≥24-hour continuous ECG monitoring, according to current stroke guidelines). All patients will be followed up for at least 12 months. OUTCOMES: The primary end point is newly detected AF (≥30 seconds) after 6 months, confirmed by an independent adjudication committee. We plan to complete recruitment in autumn 2014. First results can be expected by spring 2016.

Passive-fixation lead failure rates and long-term patient mortality in subjects implanted with Sprint Fidelis electrodes.

AIMS: To evaluate passive-fixation lead failure rates and long-term patient survival in subjects implanted with Sprint Fidelis electrodes. METHODS AND RESULTS: We identified 748 subjects who received a Sprint Fidelis (n = 429; Medtronic models 6948: 94.8%, 6949: 2.6%, 6930: 1.9%, 6931: 0.7%) or a Sprint 'non-Fidelis' implantable cardioverter defibrillator lead (n = 319, Medtronic models 6944: 68.6%, 6947: 17.9%, 6942: 7.8%, 6943: 3.4%, 6945: 2.2%) at our centre between 1998 and 2008. Kaplan-Meier patient survival was lower in the Fidelis group than in the Control cohort (68.4 vs. 77.0% at 5 years, P = 0.0061), but multivariate analyses revealed no significant association between mortality and implanted lead type. Passive-fixation lead failure rate at 5 years was 14.4% (95% confidence interval (CI) [9.2, 19.3]) in the Fidelis (n = 414) group and 1.8% (95% CI [0.0-3.8]) in the Control (n = 241) cohort (P < 0.001 upon multivariate comparison). CONCLUSION: Failure rates of passive-fixation Sprint Fidelis leads are increased and similar to those previously reported for active-fixation Fidelis electrodes. Despite the elevated risk for lead failure and its potential sequelae, the Sprint Fidelis has no obvious impact on long-term mortality.

Sex differences in ICD benefit.

BACKGROUND: Implantable cardioverter defibrillators (ICD) have been demonstrated to improve survival, but a considerable number of patients never receive appropriate therapy. The influence of sex on ICD effectiveness in primary prophylactic ICD therapy is unclear. SUMMARY: Until now, guideline recommendations are equal for men and women, yet only an average of 20% of enrolled patients in large randomized ICD studies were women. Epidemiological data from the Framingham Heart Study exhibit lower incidences of SCD in women (≈50%). This difference is in only in part owed to less severe underlying cardiac disease or comorbidities but it persists after correction of confounding factors. Several of the large randomized studies have conducted gender substudies. In MADIT-II, the survival benefit for women was similar as for men, although the risk of appropriate ICD therapy was lower for women. In SCD-HeFT and DEFINITE, the survival benefits for women were less compared to men, or not existent. Trends were contradictingly summarized by two meta-analyses. By this important post-hoc research, important hypotheses for prospective work in the ICD subgroup of women are generated. At the same time, it is undisputed that the complication rate of ICD implantations is higher in women. The largest ICD registry to date Ontario (Canada) confirms the lower appropriate shock rate in women but found no differences in total mortality. CONCLUSIONS: Further subgroup analyses of large ICD cohorts by sex are needed, as well as studies investigating the influence of sex on ICD treatment--and potentially ICD indication--prospectively.

Measurement of Left Atrial Pressure is a Good Predictor of Freedom From Atrial Fibrillation.

BACKGROUND: It is suggested that an elevated left atrial pressure (LAP) promotes ectopic beats emanating in the pulmonary veins (PVs) and that LAP might be a marker for structural remodeling. This study aimed to identify if the quantification of LAP correlates with structural changes of the LA and may therefore be associated with outcomes following pulmonary vein isolation (PVI). METHODS: We analysed data from 120 patients, referred to PVI due to drug-refractory atrial fibrillation (AF) (age 63±8; 57% men). The maximum (mLAP) and mean LAP (meLAP) were measured after transseptal puncture. RESULTS AND CONCLUSIONS: Within a mean follow-up of 303±95 days, 60% of the patients maintained in sinus rhythm after the initial procedure and 78% after repeated PVI. Performing univariate Cox-regression analysis, type of AF, LA-volume (LAV), mLAP and the meLAP were significant predictors of recurrence after PVI (p=0.03; p=0.001; p=0.01). In multivariate analysis mLAP>18mmHg, LAV>100 ml and the presence of persistent AF were significant predictors (p=0.001; p=0.019; p=0.017). The mLAP >18 mmHg was associated with a hazard ratio of 3.8. Analyzing receiver-operator characteristics, the area under the curve for mLAP was 0.75 (p<0.01). mLAP >18 mmHg predicts recurrence with a sensitivity of 77 % and specificity of 60 %. There was a linear correlation between the LAV from MDCT and mLAP (p = 0.01, R2 = 0.61). The mLAP measured invasively displays a significant predictor for AF recurrence after PVI. There is a good correlation between LAP and LAV and both factors may be useful to quantify LA remodeling.

High-sensitivity troponin assay improves prediction of cardiovascular risk in patients with cerebral ischaemia.

BACKGROUND AND PURPOSE: Clinical scores are recommended for predicting cardiovascular risk in patients with cerebral ischaemia to inform secondary prevention. Blood biomarkers may improve prediction beyond clinical scores. METHODS: Within the observational Find-AF trial (ISRCTN46104198), 197 patients >18 years of age with cerebral ischaemia and without atrial fibrillation had blood sampled at baseline. The predictive value of five biomarkers for a combined vascular endpoint (acute coronary syndrome, stroke, cardiovascular death) and all-cause mortality was determined, alone and in addition to the Essen Stroke Risk Score (ESRS), Stroke Prognostic Instrument 2 (SPI-2) and National Institutes of Health Stroke Scale (NIH-SS). RESULTS: There were 23 vascular events (11.7%) and 13 deaths (6.6%) to 1 year follow-up. In multivariate analyses of all markers, only high-sensitivity troponin T (hsTropT) remained independently predictive for vascular events (p=0.045) and all-cause mortality (p=0.004). hsTropT was higher in patients with a vascular event (median 12.7 ng/ml vs 5.1 ng/ml), and patients with hsTropT above the median of 6.15 ng/ml had vascular events more frequently (HR 3.86, p=0.008). For prediction of vascular events as well as all-cause mortality, hsTropT significantly improved multivariate Cox regression models with ESRS, SPI-2 or NIH-SS. The c-statistic increased non-significantly from 0.695 (ESRS) or 0.710 (hsTropT) to 0.747 (ESRS+hsTropT) and from 0.699 (SPI-2) to 0.763 (SPI-2+hsTropT). No patient with a low-risk ESRS and an hsTropT below the median had a vascular event or died. CONCLUSIONS: hsTropT predicts vascular events and all-cause mortality in patients with acute cerebral ischaemia and improves prediction beyond established clinical scores.

Rationale, objectives, and design of the EUTrigTreat clinical study: a prospective observational study for arrhythmia risk stratification and assessment of interrelationships among repolarization markers and genotype.

AIMS: The EUTrigTreat clinical study has been designed as a prospective multicentre observational study and aims to (i) risk stratify patients with an implantable cardioverter defibrillator (ICD) for mortality and shock risk using multiple novel and established risk markers, (ii) explore a link between repolarization biomarkers and genetics of ion (Ca(2+), Na(+), K(+)) metabolism, (iii) compare the results of invasive and non-invasive electrophysiological (EP) testing, (iv) assess changes of non-invasive risk stratification tests over time, and (v) associate arrythmogenomic risk through 19 candidate genes. METHODS AND RESULTS: Patients with clinical ICD indication are eligible for the trial. Upon inclusion, patients will undergo non-invasive risk stratification, including beat-to-beat variability of repolarization (BVR), T-wave alternans, T-wave morphology variables, ambient arrhythmias from Holter, heart rate variability, and heart rate turbulence. Non-invasive or invasive programmed electrical stimulation will assess inducibility of ventricular arrhythmias, with the latter including recordings of monophasic action potentials and assessment of restitution properties. Established candidate genes are screened for variants. The primary endpoint is all-cause mortality, while one of the secondary endpoints is ICD shock risk. A mean follow-up of 3.3 years is anticipated. Non-invasive testing will be repeated annually during follow-up. It has been calculated that 700 patients are required to identify risk predictors of the primary endpoint, with a possible increase to 1000 patients based on interim risk analysis. CONCLUSION: The EUTrigTreat clinical study aims to overcome current shortcomings in sudden cardiac death risk stratification and to answer several related research questions. The initial patient recruitment is expected to be completed in July 2012, and follow-up is expected to end in September 2014. Clinicaltrials.gov identifier: NCT01209494.

Long-Term Follow-up of Enhanced Holter-Electrocardiography Monitoring in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Prolonged electrocardiography (ECG)-monitoring in stroke patients improves the detection of paroxysmal atrial fibrillation (pAF). However, most randomized studies only had short follow-up. We aimed to provide 3-year follow-up data for AF detection and stroke recurrence risk. METHODS: We randomized 402 patients aged ≥60 years with acute ischemic strokes without AF to either enhanced and prolonged monitoring (EPM; 3×10-day Holter-ECG-monitoring) or standard-of-care (≥24 hours ECG-monitoring). The endpoint of the current analysis was AF within 36 months analyzed by intention to treat. Long-term follow-up was performed for 36 months. RESULTS: Two hundred and seventy-four patients (80%) participated in the extended follow-up (median duration of follow-up was 36 months [interquartile range, 12 to 36]). During the first 6 months, more AF was documented in the EPM arm compared to the control arm (13.5% vs. 5.1%; 95% confidence interval, 2.9% to 14.4%; P=0.004). During months 6 to 36, AF was less detected in the EPM intervention arm than in the control arm (2.0% vs. 7.3%; 95% confidence interval, 0.7% to 9.9%; P=0.028). Overall, the detection rate of AF within 36 months was numerically higher within the EPM group (15.0% vs. 11.1%, P=0.30). Numerically less patients in the EPM arm had recurrent ischemic strokes (5.5% vs. 9.1%, P=0.18), transient ischemic attacks (3.0% vs. 4.5%, P=0.44) or died (4.5% vs. 6.6%, P=0.37). CONCLUSIONS: Enhanced and prolonged ECG monitoring increased AF detection during the first six months, but there was significantly more clinical AF during months 6 to 36 observed in the usual-care arm. This suggests that EPM leads to an earlier detection of clinically relevant AF.

Acute and long-term feasibility of contralateral transvenous lead placement with subcutaneous, pre-sternal tunnelling in patients with chronically implanted rhythm devices.

AIMS: A growing number of patients with implanted rhythm devices require new or additional leads, e.g. in cases of electrode defect or planned device upgrade. If the ipsilateral subclavian vein is occluded, transvenous electrode placement from the contralateral side with subcutaneous, pre-sternal lead tunnelling (TUN) is one potential option that has been described in anecdotal reports. The aim of this retrospective study was to determine the acute and long-term feasibility of this approach. METHODS AND RESULTS: We identified 18 subjects (67% male, 66±14 years) who underwent TUN at our institution between the years 1995 and 2009. Implantation protocols and patient files were reviewed for peri-operative complications and long-term lead performance. Furthermore, patients were interviewed for symptoms related to the tunnelled lead. Twenty transvenous leads (seven implantable cardioverter defibrillator leads; five left ventricular, four right ventricular, four right atrial pace/sense electrodes) were successfully tunnelled without significant peri-operative complications. The follow-up duration was 29±36 (3-162) months. Electrical parameters remained stable in 95% (19/20) of the tunnelled leads. In one right ventricle pace/sense lead, ventricular oversensing was documented 10 months after TUN, and the lead was replaced because a structural defect could not be excluded. Five patients died without causal relationship to the procedure 4-48 months after TUN. One patient reported discomfort related to the tunnelled lead. CONCLUSION: Contralateral transvenous lead implantation with subcutaneous, pre-sternal TUN appears to be a feasible option in selected patients with an implanted rhythm device and ipsilateral subclavian vein occlusion.

T-wave alternans testing in pacemaker patients: comparison of pacing modes and long-term prognostic relevance.

BACKGROUND: T-wave alternans (TWA) is a useful method for identifying patients who are at risk for sudden cardiac death. We aimed to determine the effects of different pacing modes on test results and long-term prognostic relevance of TWA in patients following a dual-chamber (DDD) pacemaker implantation. METHODS: Sixty-three patients (mean age 68 ± 13 years) with structural heart disease and recently implanted DDD pacemakers were enrolled. Left ventricular (LV) function was normal or moderately impaired (mean LV ejection fraction 61 ± 13%). All patients underwent sequential TWA testing using atrial and ventricular pacing. RESULTS: During atrial pacing requiring physiologic conduction to the ventricles, 21% of TWA tests were positive, 43% negative, and 36% indeterminate. When using right ventricular (RV) pacing in the same patients, 19% of tests were positive, 40% negative, and 41% indeterminate. When positive and indeterminate tests were grouped as nonnegative, the concordance between atrial and ventricular pacing was 62% (κ= 0.22). After a mean follow-up of 5.9 ± 1.9 years, 18 (29%) patients had died. Improved survival was predicted by a negative TWA test using atrial pacing (P = 0.028), but not with ventricular pacing (P = 0.722). CONCLUSIONS: In patients with dual-chamber pacemakers, there is a low concordance of TWA test results between atrial pacing with intrinsic conduction to the ventricles and apical RV pacing via pacemaker electrode. However, TWA during atrial pacing clearly exerts long-term prognostic relevance in a patient group with preserved LV function and structural heart disease.

Enhanced detection of paroxysmal atrial fibrillation by early and prolonged continuous holter monitoring in patients with cerebral ischemia presenting in sinus rhythm.

BACKGROUND AND PURPOSE: Diagnosis of paroxysmal atrial fibrillation is difficult but highly relevant in patients presenting with cerebral ischemia yet free from atrial fibrillation on admission. Early initiation and prolongation of continuous Holter monitoring may improve diagnostic yield compared with the standard of care including a 24-hour Holter recording. METHODS: In the observational Find-AF trial (ISRCTN 46104198), consecutive patients presenting with symptoms of cerebral ischemia were included. Patients free from atrial fibrillation at presentation received 7-day Holter monitoring. RESULTS: Two hundred eighty-one patients were prospectively included. Forty-four (15.7%) had atrial fibrillation documented by routine electrocardiogram on admission. All remaining patients received Holter monitors at a median of 5.5 hours after presentation. In those 224 patients who received Holter monitors but had no previously known paroxysmal atrial fibrillation, the detection rate with early and prolonged (7 days) Holter monitoring (12.5%) was significantly higher than for any 24-hour (mean of 7 intervals: 4.8%, P = 0.015) or any 48-hour monitoring interval (mean of 6 intervals: 6.4%, P = 0.023). Of those 28 patients with new atrial fibrillation on Holter monitoring, 15 (6.7%) had been discharged without therapeutic anticoagulation after routine clinical care (ie, with data from 24-hour Holter monitoring only). Detection rates were 43.8% or 6.3% for short supraventricular runs of ≥ 10 beats or prolonged episodes (> 5 hours) of atrial fibrillation, respectively. Diagnostic yield appeared to be only slightly and not significantly increased during the first 3 days after the index event. CONCLUSIONS: Prolongation of Holter monitoring in patients with symptoms of cerebral ischemic events increases the rate of detection of paroxysmal atrial fibrillation up to Day 7, leading to a relevant change in therapy in a substantial number of patients. Early initiation of monitoring does not appear to be crucial. Hence, prolonged Holter monitoring (≥ 7 days) should be considered for all patients with unexplained cerebral ischemia.

Ventricular oversensing due to manufacturer-related differences in implantable cardioverter-defibrillator signal processing and sensing lead properties.

AIMS: Ventricular oversensing remains a significant problem in modern implantable cardioverter-defibrillator (ICD) systems. The role of manufacturer-related differences in device-based signal processing on the one hand and sensing lead properties on the other is largely unknown. This retrospective study aimed to evaluate and compare the incidence and mechanisms of ventricular oversensing in single- or dual-chamber ICD systems from Biotronik (BTK), Guidant (GDT), and Medtronic (MDT). METHODS AND RESULTS: In 245 consecutive patients, device function, stored episodes, and lead parameters were evaluated at implant and during 243 ± 18 days of follow-up. Oversensing occurred in 3.3% of the patients [four T-wave oversensing (TWO), three R-wave double-sensing, and one diaphragmatic myopotentials]. The incidence of ventricular oversensing was generally low if an ICD device and an ICD lead were from one identical manufacturer (BTK: 2/68, GDT: 1/80, and MDT: 1/69; P = 0.67). In the subgroup of ICDs connected to leads from other manufacturers, however, ventricular oversensing was observed in none of 19 GDT and MDT ICDs but in 4 of 9 BTK devices (44.4%, P = 0.012). These four cases of oversensing (three R-wave double-sensing and one TWO) all occurred in BTK ICDs connected to integrated bipolar ICD leads from other manufacturers. CONCLUSION: Significant manufacturer-related differences exist in the incidence of ventricular oversensing in single- and dual-chamber ICD systems. Biotronik devices connected to integrated bipolar ICD leads from other manufacturers have an increased risk for R-wave double-sensing.