Risk of occurrence of electromagnetic interference from the application of transcutaneous electrical nerve stimulation on the sensing function of implantable defibrillators

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is an established method for pain relief. But electrical TENS currents are also a source of electromagnetic interference (EMI). Thus, TENS is considered to be contraindicated in implantable cardioverter-defibrillator (ICD) patients. However, data might be outdated due to considerable advances in ICD and cardiac resynchronization therapy (CRT) filtering and noise protection algorithm technologies. The aim of this pilot safety study was to re-evaluate the safety of TENS in patients with modern ICDs.

METHODS AND RESULTS

One hundred and seven patients equipped with 55 different models of ICD/CRT with defibrillators from 4 manufacturers underwent a standardized test protocol including TENS at the cervical spine and the thorax, at 2 stimulation modes-high-frequency TENS (80 Hz) and burst-mode TENS (2 Hz). Potential interference monitoring included continuous documentation of ECG Lead II, intracardiac electrograms and the marker channel. Electromagnetic interference was detected in 17 of 107 patients (15.9%). Most frequent were: interpretations as a premature ventricular beats (VS/S) in 15 patients (14%), noise reversion in 5 (4.6%) which resulted in temporary asynchronous pacing in 3 (2.8%), interpretation as ventricular tachycardia/ventricular fibrillation in 2 (1.9%), and premature atrial beat in 2 (1.9%) patients. Electromagnetic interference occurrence was influenced by position (chest, P < 0.01), higher current intensity (P < 0.01), and manufacturer (P = 0.012).

CONCLUSION

Overall, only intermittent and minor EMI were detected. Prior to the use of TENS in patients with ICDs, they should undergo testing under the supervision of a cardiac device specialist.

Closed loop stimulation in patients with chronic heart failure and severe chronotropic incompetence: Responders versus non-responders

BACKGROUND

Clinical effects of rate-adaptive pacing (RAP) are unpredictable and highly variable among cardiac resynchronization therapy (CRT) patients with chronotropic incompetence. Physiologic sensors such as Closed Loop Stimulation (CLS), measuring intracardiac impedance changes (surrogate for ventricular contractility), may add clinical benefit and help identify predictors of response to RAP. The objective of the present BIOlCREATE study subanalysis was to identify criteria for selection of CRT patients who are likely to respond positively to CLS-based RAP.

METHODS

In the randomized, crossover BIO|CREATE study, CRT patients with severe chronotropic incompetence and NYHA class II/III were randomized to CLS with conventional upper sensor rate programming or to no RAP for 1 month, followed by crossover for another month. At 1-month and 2-month follow-ups, patients underwent treadmill-based cardiopulmonary exercise test. Positive CLS response was defined as a ≥ 5% reduction in ventilatory efficiency slope. Eight of 17 patients (47%) were CLS responders. In this subanalysis, we compared responders and non-responders to explore outcomes, mechanisms, and predictors.

RESULTS

All cardiopulmonary variables, health-related quality of life, patient activity status, and NT-proBNP concentration showed favorable trend in CLS responders and unfavorable trend in non-responders, underlining the need to find predictors. Following all analyses, we recommend CLS in heart failure patients with improved left ventricular ejection fraction (LVEF >40%, after a ≥ 10-point increase from a CRT-pre-implant value of ≤40%), corresponding to 'HFimpEF' in the universal classification system.

CONCLUSION

HFimpEF patients are likely to benefit from CLS-based RAP, in contrast to 'HFrEF' (heart failure with reduced LVEF [≤40%]).

Closed loop stimulation in heart failure patients with severe chronotropic incompetence: responder versus non-responders

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Biotronik SE & Co. KG Woermannkehre 1 12359 Berlin

Background

The prevalence of chronotropic incompetence (CI) in heart failure (HF) population is high and negatively impacts prognosis. Rate-adaptive pacing (RAP) is an important treatment option for CI. However, only a proportion of HF patients treated with cardiac resynchronisation therapy (CRT) devices benefit from accelerometer-based RAP in terms of exercise tolerance, functional capacity, and quality of life (QoL). Further research is needed to identify patient characteristics predicting positive response to RAP, and to evaluate performance of alternative sensors such as closed loop stimulation (CLS) driven by cardiac impedance measurements. An optimal outcome measure is represented by ventilatory efficiency (VE) slope during cardio-pulmonary exercise test (CPX) because of superior prognostic value.

Purpose

The purpose of the BIO|Create pilot study was to assess the benefit of CLS in CRT patients with CI. In this predefined subanalysis, we identify predictors of positive response to CLS (reduction of VE slope by ≥5%) and compare study outcomes in responders vs non-responders.

Methods

The study enrolled CRT patients with NYHA class II or III and severe CI (&lt;75% of age-predicted maximum heart rate [HR] or &lt;50% of HR reserve utilised at end-exercise). Patients were randomised to DDD-CLS mode or to DDD pacing at 40 beats/min for 1 month, followed by crossover for another month. At 1- and 2-month follow-ups, exercise tolerance was assessed by treadmill CPX, functional capacity by 6-min walk test, and QoL by the EQ-5D-5L and Minnesota Living with HF (MLHFQ) questionnaires.

Results

Among 17 patients with full follow-up datasets, 8 (47%) were responders to CLS. Compared to non-responders, responders had larger left ventricular (LV) ejection fraction at baseline (46 ± 3 vs 36 ± 9 %; p = 0.0070), smaller end-diastolic (121 ± 34 vs 181 ± 41 ml; p = 0.0085) and end-systolic (65 ± 23 vs 114 ± 39 ml; p = 0.0076) LV volumes, and were predominantly in NYHA class II (p = 0.0498). For study outcomes, the mean difference between DDD-CLS and DDD-40 modes in responders vs non-responders was - 6.1 (-16.4%) vs +2.7 (+6.8%) for VE slope (both p &lt; 0.05), +0.5 vs -0.2 ml/min (O2 uptake efficiency slope), +1.3 vs -0.3 ml/kg/min (peak O2 uptake), +1.4 vs -0.75 mmHg (end-exercise end-tidal CO2), 16 vs 7 m (6-min walk distance), 0.08 vs 0.06 (EQ-5D-5L index), 1.9 vs 0 (EQ-5D-5L scale), and -2.5 vs +1.75 (MLHFQ).

Conclusions

For the first time, predictors for positive outcome of RAP in CRT patients have been identified. Patients with less advanced HF were responders to RAP driven by CLS principle. In addition, a consistent increase in exercise and functional capacity and QoL in these patients could be achieved. In contrast, patients with advanced HF experienced worse exercise capacity and QoL during RAP, suggesting caution if RAP is desirable due to CI. Further clinical research is needed to evaluate if positive response to RAP can improve hard clinical outcomes.

Benefit of a wearable cardioverter defibrillator for detection and therapy of arrhythmias in patients with myocarditis

Aims

Myocarditis may lead to malignant arrhythmias and sudden cardiac death. As of today, there are no reliable predictors to identify individuals at risk for these catastrophic events. The aim of this study was to evaluate if a wearable cardioverter defibrillator (WCD) may detect and treat such arrhythmias adequately in the peracute setting of myocarditis.

Methods and results

In this observational, retrospective, single centre study, we reviewed patients presenting to the Charité Hospital from 2009 to 2017, who were provided with a WCD for the diagnosis of myocarditis with reduced ejection fraction (<50%) and/or arrhythmias. Amongst 259 patients receiving a WCD, 59 patients (23%) were diagnosed with myocarditis by histology. The mean age was 46 ± 14 years, and 11 patients were women (19%). The mean WCD wearing time was 86 ± 63 days, and the mean daily use was 20 ± 5 h. During that time, two patients (3%) had episodes of sustained ventricular tachycardia (VT; four total) corresponding to a rate of 28 sustained VT episodes per 100 patient‐years. Consequently, one of these patients underwent rhythm stabilization through intravenous amiodarone, while the other patient received an implantable cardioverter defibrillator. Two patients (3.4%) were found to have non‐sustained VT.

Conclusions

Using a WCD after acute myocarditis led to the detection of sustained VT in 2/59 patients (3%). While a WCD may prevent sudden cardiac death after myocarditis, our data suggest that WCD may have impact on clinical management through monitoring and arrhythmia detection.

Creation of physiologic rhythm by closed loop stimulation in heart failure patients with severe chronotropic incompetence: worldwide first results of a pilot study

Background

The prevalence of chronotropic incompetence (CI) in heart failure (HF) population is high and negatively impacts prognosis. In HF patients with an implanted cardiac resynchronisation therapy (CRT) device and severe CI, the effect of rate adaptive pacing on patient outcomes is unclear. Closed loop stimulation (CLS) based on cardiac impedance measurement may be an optimal method of heart rate adaptation according to metabolic need in HF patients with severe CI.

Purpose

This is the first study evaluating the effect of CLS on the established prognostic parameters assessed by the cardio-pulmonary exercise (CPX) testing and on quality of life (QoL) of the patients.

Methods

A randomised, controlled, double-blind and crossover pilot study has been performed in CRT patients with severe CI defined as the inability to achieve 70% of the age-predicted maximum heart rate (APMHR). After baseline assessment, patients were randomised to either DDD-CLS pacing (group 1) or DDD pacing at 40 bpm (group 2) for a 1-month period, followed by crossover for another month. At baseline and at 1- and 2-month follow-ups, a CPX was performed and QoL was assessed using the EQ-5D-5L questionnaire. The main endpoints were the effect of CLS on ventilatory efficiency (VE) slope (evaluated by an independent CPX expert), the responder rate defined as an improvement (decrease) of the VE slope by at least 5%, percentage of maximal predicted heart rate reserve (HRR) achieved, and QoL.

Results

Of the 36 patients enrolled in the study, 20 fulfilled the criterion for severe CI and entered the study follow-up (mean age 68.9±7.4 years, 70% men, LVEF=41.8±9.3%, 40%/60% NYHA class II/III). Full baseline and follow-up datasets were obtained in 17 patients. The mean VE slope and HRR at baseline were 34.4±4.4 and 49.6±23.8%, respectively, in group 1 (n=7) and 34.5±12.2 and 54.2±16.1% in group 2 (n=10). After completing the 2-month CPX, the mean difference between DDD-CLS and DDD-40 modes was −2.4±8.3 (group 1) and −1.2±3.5 (group 2) for VE slope, and 17.1±15.5% (group 1) and 8.7±18.8% (group 2) for HRR. Altogether, VE slope improved by −1.8±2.95 (p=0.31) in DDD-CLS versus DDD-40, and HRR improved by 12.9±8.8% (p=0.01). The VE slope decreased by ≥5% in 47% of patients (“responders to CLS”). The mean difference in the QoL between DDD-CLS and DDD-40 was 0.16±0.25 in group 1 and −0.01±0.05 in group 2, resulting in an overall increase by 0.08±0.08 in the DDD-CLS mode (p=0.13).

Conclusion

First results of the evaluation of the effectiveness of CLS in CRT patients with severe CI revealed that CLS generated an overall positive effect on well-established surrogate parameters for prognosis. About one half of the patients showed CLS response in terms of improved VE slope. In addition, CLS improved quality of life. Further clinical research is needed to identify predictors that can increase the responder rate and to confirm improvement in clinical outcomes.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Biotronik SE & Co. KG

Protected risk stratification with the wearable cardioverter-defibrillator: results from the WEARIT-II-EUROPE registry

Background

The prospective WEARIT-II-EUROPE registry aimed to assess the value of the wearable cardioverter-defibrillator (WCD) prior to potential ICD implantation in patients with heart failure and reduced ejection fraction considered at risk of sudden arrhythmic death.

Methods and results

781 patients (77% men; mean age 59.3 ± 13.4 years) with heart failure and reduced left ventricular ejection fraction (LVEF) were consecutively enrolled. All patients received a WCD. Follow-up time for all patients was 12 months. Mean baseline LVEF was 26.9%. Mean WCD wearing time was 75 ± 47.7 days, mean daily WCD use 20.3 ± 4.6 h. WCD shocks terminated 13 VT/VF events in ten patients (1.3%). Two patients died during WCD prescription of non-arrhythmic cause. Mean LVEF increased from 26.9 to 36.3% at the end of WCD prescription (p < 0.01). After WCD use, ICDs were implanted in only 289 patients (37%). Forty patients (5.1%) died during follow-up. Five patients (1.7%) died with ICDs implanted, 33 patients (7%) had no ICD (no information on ICD in two patients). The majority of patients (75%) with the follow-up of 12 months after WCD prescription died from heart failure (15 patients) and non-cardiac death (15 patients). Only three patients (7%) died suddenly. In seven patients, the cause of death remained unknown.

Conclusions

Mortality after WCD prescription was mainly driven by heart failure and non-cardiovascular death. In patients with HFrEF and a potential risk of sudden arrhythmic death, WCD protected observation of LVEF progression and appraisal of competing risks of potential non-arrhythmic death may enable improved selection for beneficial ICD implantation.

Graphic abstract

[Informations on psychotropics and their adaptations for patients suffering from mental disorders in France during the SARS-CoV-2 epidemic]

The 2019-20 coronavirus pandemic (SARS-CoV-2; severe acute respiratory syndrome coronavirus 2) has dramatic consequences on populations in terms of morbidity and mortality and in social terms, the general confinement of almost half of the world's population being a situation unprecedented in history, which is difficult today to measure the impact at the individual and collective levels. More specifically, it affects people with various risk factors, which are more frequent in patients suffering from psychiatric disorders. Psychiatrists need to know: (i) how to identify, the risks associated with the prescription of psychotropic drugs and which can prove to be counterproductive in their association with COVID-19 (coronavirus disease 2019), (ii) how to assess in terms of benefit/risk ratio, the implication of any hasty and brutal modification on psychotropic drugs that can induce confusion for a differential diagnosis with the evolution of COVID-19. We carried out a review of the literature aimed at assessing the specific benefit/risk ratio of psychotropic treatments in patients suffering from COVID-19. Clinically, symptoms suggestive of COVID-19 (fever, cough, dyspnea, digestive signs) can be caused by various psychotropic drugs and require vigilance to avoid false negatives and false positives. In infected patients, psychotropic drugs should be used with caution, especially in the elderly, considering the pulmonary risk. Lithium and Clozapine, which are the reference drugs in bipolar disorder and resistant schizophrenia, warrant specific attention. For these two treatments the possibility of a reduction in the dosage - in case of minimal infectious signs and in a situation, which does not allow rapid control - should ideally be considered taking into account the clinical response (even biological; plasma concentrations) observed in the face of previous dose reductions. Tobacco is well identified for its effects as an inducer of CYP1A2 enzyme. In a COVID+ patient, the consequences of an abrupt cessation of smoking, particularly related with the appearance of respiratory symptoms (cough, dyspnea), must therefore be anticipated for patients receiving psychotropics metabolized by CYP1A2. Plasma concentrations of these drugs are expected to decrease and can be related to an increase risk of relapse. The symptomatic treatments used in COVID-19 have frequent interactions with the most used psychotropics. If there is no curative treatment for infection to SARS-CoV-2, the interactions of the various molecules currently tested with several classes of psychotropic drugs (antidepressants, antipsychotics) are important to consider because of the risk of changes in cardiac conduction. Specific knowledge on COVID-19 remains poor today, but we must recommend rigor in this context in the use of psychotropic drugs, to avoid adding, in patients suffering from psychiatric disorders, potentially vulnerable in the epidemic context, an iatrogenic risk or loss of efficiency.

Velocity characteristics of atrial fibrillation sources determined by electrographic flow mapping before and after catheter ablation

BACKGROUND

Electrographic-Flow-(EGF)-Mapping is a novel method to identify Atrial Fibrillation (AF) drivers. Sources of excitation during AF can be characterized and monitored.

OBJECTIVE

The aim of this study was to evaluate the correlation between velocity of EGF around a respective AF source and its spatial variability (SV) and stability (SST).

METHODS

25 patients with AF were included in this study (persistent: n = 24, long-standing persistent: n = 1; mean age 70 ± 8.3 years, male: n = 17). Focal impulse and Rotor-Mapping (FIRM) was performed in addition to pulmonary vein isolation. One-minute epochs of unipolar electrograms recorded via a 64-pole basket catheter in both atria were re-analyzed with EGF-Mapping. SST was calculated as the percentage of time in which a source was detected.

RESULTS

AF sources identified with EGF-Mapping show a wide range of SV during 1 min covering between 0.12% and 38% of the recorded basket-catheter surface. The 12 atria where the sources showed highest temporal stability (TS; between 34% and 97% of 1 min recorded) and those 12 with the lowest TS (between 11 and 20%) differed significantly in their velocities (17.8 el/s vs 12.2 el/s; p < 0.01). In 11 atria ablation caused an average decrease of TS by 47% and of velocity by 27% while SV more than doubled.

CONCLUSION

Less stable AF-sources with high spatial variability showed reduced excitation propagation velocity while stable AF sources displayed a high average velocity in their vicinity. Importantly, catheter ablation reduced stability of sources and velocity suggesting a role of these parameters in guidance of ablation.

CONDENSED ABSTRACT

Electrographic Flow (EGF)-Mapping is a novel method to identify Atrial Fibrillation (AF) drivers based on modeling of an electrical potential surface and subsequent flow analysis. Sources of excitation during AF can be characterized and monitored. The aim of this study was to evaluate the correlation between velocity of EGF around a respective AF source and its spatial variability and stability. Less stable AF sources with high spatial variability showed reduced excitation propagation velocity while very stable AF sources displayed a high average velocity in their vicinity. Catheter ablation reduced stability of sources and velocity.

Cryoballoon ablation in the elderly: one year outcome and safety of the second-generation 28mm cryoballoon in patients over 75 years old

Aims

The efficacy of the second-generation cryoballoon (CB) ablation in patients with atrial fibrillation (AF) has been demonstrated previously. Data on the efficacy of CB ablation in elderly patients is missing. The aim of this study was to evaluate the long-term success rate of pulmonary vein isolation (PVI) in patients ≥75 years vs. <75 years using the second-generation 28mm CB.

Methods and results

Eighty patients [n = 40 ≥75 years (Group 1); n = 40 <75 years (Group 2)] with paroxysmal [n = 37 (46%) or persistent (n = 43 (54%)] AF were included. Median follow-up was 12 [6;18] months (Group 1 vs. 13 [6;27]) months (Group 2; P = 0.8). PVI was performed in all patients using cryoablation. Follow-up was obtained using 24h-Holter monitoring or via an implanted loop recorder or pacemaker. CHA2DS2VASc-Score (Group 1: 4 [4;5] vs. Group 2: 2 [1;3], P < 0.001) and HASBLED-Score (Group 1: 2 [2;3] and Group 2: 2 [1;3], (P = 0.009)) differed significantly between the two groups. Mean fluoroscopy time was 22.9 [16.3;31.9] in Group 1 and 24.5 [19.1;30.6] in Group 2 (P = 0.75), and mean procedure time was 125 min [105;151] in Group 1 and 130.5 min [117.5;147.3] in Group 2 (P = 0.66). Arrhythmia recurrence was similar in Group 1 and Group 2 (12/40 (30%) vs. 10/40 (25%) (P = 0.62). One transient ischaemic attack occurred in Group 2. No further major complications were documented in this patients cohort.

Conclusion

CB ablation in patients ≥75 years has favourable success rates and similar complication rates compared with patients <75 years.

Left atrial appendage angiography is associated with the incidence and number of magnetic resonance imaging-detected brain lesions after percutaneous catheter-based left atrial appendage closure

BACKGROUND

Percutaneous catheter-based left atrial appendage closure (LAAC) is a procedure being increasingly performed in patients with atrial fibrillation and high bleeding risk.

OBJECTIVE

The purpose of this study was to evaluate the incidence of magnetic resonance imaging (MRI)-detected acute brain lesions (ABLs) as well as potential changes in neurocognitive function after percutaneous LAAC in patients with atrial fibrillation.

METHODS

Brain MRI at 3 T was performed within 24 hours before and after LAAC along with neurologic (National Institutes of Health Stroke Scale [NIHSS] score) and cognitive (Montreal Cognitive Assessment [MoCA] test) assessment. Acquired MRI sequences included high-resolution diffusion-weighted imaging as well as fluid-attenuated inversion recovery.

RESULTS

Successful device implantation was achieved in all 23 patients (age 74.1 ± 10.5 years; 16 male) using the Amulet (n = 18), Occlutech (n = 3), or LAmbre (n = 2) device. Thirty-seven ABLs were detected by MRI in 12 of 23 patients (52%) after LAAC. The number of periprocedural LAA angiographies was significantly higher in patients with ABL than in those without ABL (1.67 ± 0.65 vs 1.18 ± 0.41; P = .048) and was associated with a higher number of ABL (ρ = 0.615; P = .033). Compared to pre-LAAC assessment, post-LAAC MoCA and NIHSS scores revealed similar results. After LAAC, MoCA test (mean 24.1 ± 4.6 vs 23.2 ± 4.6; P = .09) and NIHSS score (mean 1.0 ± 1.7 vs 1.2 ± 1.8; P = .1) were similar between patients with and those without ABL, respectively.

CONCLUSION

MRI-detected ABLs are commonly observed after percutaneous LAAC. The number of LAA angiographies is significantly associated with the number of ABLs; however, the clinical implications of ABL have yet to be determined.

Long-term follow up of 3 T MRI-detected brain lesions after percutaneous catheter-based left atrial appendage closure

BACKGROUND

Left atrial appendage closure (LAAC) for stroke prevention is an increasingly performed intervention.

AIMS

This prospective study aims to evaluate the incidence of long-term magnetic resonance imaging (MRI)-detected brain lesions as well as potential changes of neurocognitive function after percutaneous LAAC.

METHODS

Brain MRI at 3 T was performed within 24 hr before and after LAAC. A follow-up MRI was carried out after three months. Neuro-cognitive examination using the National Institutes of Health Stroke Scale (NIHSS) score and the Montreal Cognitive Assessment (MoCA) Test was performed.

RESULTS

Successful device implantation was achieved in all 25 patients (age 74.6 ± 10.2 years, male = 17) using the Amulet (n = 20), Occlutech (n = 3), or a Lambre (n = 2) device. In 12/25 (48%) patients, acute brain lesions (ABL) were detected after LAAC. A three-month follow-up MRI was performed in seven patients, and no new ABLs were seen. In 5/7 (71%) patients, there were no residual changes from the ABLs detectable. However, the FLAIR sequence was still positive in two patients. After LAAC, there were no significant differences in the MoCA-test (mean 24.3 ± 4.5 vs. 23.5 ± 4.5; P = 0.1) and the NIHSS-score (mean 0.9 ± 1.6 vs. 1.2 ± 1.8; P = 0.1). This was the same at the three-month follow-up (MoCA-test 23.5 ± 4.5 vs. 23.8 ± 2.7; P = 0.3; NIHSS-score 1.2 ± 1.8 vs. 1.0 ± 0.8; P = 0.4).

CONCLUSION

While new MRI-detected brain lesions are commonly observed after percutaneous LAAC, ABLs were no longer detectable in 71% of the patients at the three-month follow-up. There were no significant changes in neurocognitive function after LAAC and at the three-month follow-up.

Apixaban, rivaroxaban, and dabigatran use in patients undergoing catheter ablation for atrial fibrillation using the second-generation cryoballoon

BACKGROUND

Data are limited on the safety of periprocedural anticoagulation with novel oral anticoagulants (NOACs) in patients undergoing pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB) for the treatment of atrial fibrillation.

HYPOTHESIS

We hypothesized that the incidence of acute periprocedural complications in patients undergoing PVI do not differ between patients treated with VKA compared to NOACs.

METHODS

In 200 consecutive patients (mean age, 64.3 _ 10.6 years; female, n = 83) with symptomatic atrial fibrillation, PVI using the second-generation 28-mm CB was performed. In patients treated with NOACs, the medication was stopped the day of the procedure and continued the evening after the procedure with a reduced dosage. Patients treated with phenprocoumon were continued on uninterrupted phenprocoumon with a target INR of 2 to 3. If INR was <2, bridging with low-molecular-weight heparin was performed.

RESULTS

Forty-seven of 200 patients (23.5%) were treated with a vitamin K antagonist (VKA) and 55 (27.5%) were treated with apixaban, 67 (33.5%) with rivaroxaban, and 31 (15.5%) with dabigatran. Seven (3.5%) major complications occurred in the overall population. Major bleeding complications did not differ significantly between the 2 groups (P = 0.23). One patient taking VKA had a pericardial tamponade at the end of the procedure; 2 patients treated with apixaban developed a groin hematoma requiring surgical intervention. Transient ischemic attack occurred in 1 patient of the apixaban and rivaroxaban group.

CONCLUSIONS

Apixaban, rivaroxaban, and dabigatran, compared with uninterrupted VKA, did not show a higher risk for major bleeding or ischemic complications in patients undergoing PVI using the second-generation CB.

Loop Recorder Detected High Rate of Atrial Fibrillation Recurrence after a Single Balloon- or Basket-Based Ablation of Paroxysmal Atrial Fibrillation: Results of the MACPAF Study

Purpose

Pulmonary vein isolation (PVI) is an established approach to treat symptomatic non-permanent atrial fibrillation (AF). Detecting AF recurrence after PVI is important, if discontinuation of oral anticoagulation after ablation is considered.

Methods

Patients with symptomatic paroxysmal AF were enrolled in the prospective randomized mesh ablator vs. cryoballoon pulmonary vein (PV) ablation of symptomatic paroxysmal AF study, comparing efficacy and safety of the HD Mesh Ablator^® (C.R. Bard, Lowell, MA, USA) and the Arctic Front^® (Medtronic, Minneapolis, MN, USA) catheter. Rhythm status post-PVI was closely monitored for 1 year using the implantable loop recorder (ILR) Reveal XT^® (Medtronic Minneapolis, MN, USA).

Results

The study was terminated after the first interim analysis due to the inability of the HD Mesh Ablator^® to achieve the predefined primary study endpoint, an exit block of all PVs. After a 90-day blanking period, 23 (62.2%) out of 37 study patients (median 63.0 years; 41% females) had at least one episode of AF. AF recurrence was associated with AF episodes during the blanking period {hazard ratios (HR) 5.10 [95% confidence interval (CI) 1.21–21.4]; p = 0.038}, and a common left-sided PV ostium [HR 4.17 (95%CI 1.48–11.8); p = 0.039] but not with catheter type, age, gender, cardiovascular risk profile, or left atrial volume. There was a trend toward AF recurrence in patients without complete PVI of all PV (p = 0.095). Overall, 337 (59.4%) out of 566 ILR-detected episodes represented AF. Comparing patients with AF recurrence to those without, there was no difference in cognitive performance 6 months post-ablation.

Conclusion

Using an ILR, in more than 60% of all patients with paroxysmal AF, a recurrence of AF was detected within 12 months after ablation. In patients with a common PV ostium, the first generation balloon-based catheter is obviously less effective.

Clinical trials

http://Clinicaltrials.gov NCT01061931.

Successful re-ablation of a permanent junctional reciprocating tachycardia with cryoenergy : Case report of a 19-year-old patient

We report the case of a 19-year-old male patient who presented with a permanent junctional reciprocating tachycardia (PJRT). After a primarily successful radiofrequency ablation of a para-Hisian, midseptal, accessory pathway, recurrence of tachycardia was documented. Thereafter, successful ablation using cryoenergy was performed. Since this second ablation the patient has been free of tachycardia. Our case study shows that the treatment of PJRT in young adults using cryoenergy can be successfully and safely conducted, especially after tachycardia recurrence following an initial radiofrequency ablation.

[Recurrent microdislocation of pacemaker leads due to an aortic aneurysm of the aorta ascendens]

We report about a 79 years old female patient which was admitted due to a symptomatic AV block 3rd degree. The coronary angiography excluded a coronary artery disease and the echocardiography revealed a normal left ventricular systolic function. Therefore a dual-chamber pacemaker was implanted. Following two micro-dislocations of the right ventricular lead, which required operative revisions, a computed tomography of the heart was performed. This detected an aneurysm of the ascending aorta (5 cm maximum diameter) with compression of the superior caval vein. This case shows that a possible cause of recurrent micro-dislocations could be a pathological anatomy of the heart.

[Wide QRS complex tachycardia in a patient with ischemic cardiomyopathy and prior ventricular tachycardia ablation]

CASE REPORT

This article reports the case of a 76-year-old patient with multiple implantable cardioverter defibrillator (ICD) interventions of the single chamber ICD. On admission the 12-lead electrocardiogram (ECG) documented a wide QRS complex tachycardia without clearly identifiable P waves. The patient had previously had two ventricular tachycardia (VT) ablations due to VT storms. The resting ECG revealed a sinus rhythm with a wide QRS complex. During the electrophysiological investigation typical atrial flutter could be detected and an ablation of the cavotricuspid isthmus was performed. During the follow-up period, the patient has been free from tachycardia.

CONCLUSION

The case described emphasizes that a differentiation between supraventricular tachycardia (SVT) and VT based on a stored ECG without an atrial channel can be challenging.

[Right ventricular outflow tract tachycardia 30 years after surgical correction of tetralogy of Fallot]

This case report describes a 31-year-old man with a sustained wide complex tachycardia with left bundle brunch block morphology after surgical repair of a tetralogy of Fallot. The tachycardia was inducible after orciprenaline administration after ventricular stimulation with one extra beat. In combination with the three-dimensional electroanatomic mapping system and pace mapping technique the origin of the tachycardia was identified at the lateral free wall of the right ventricular outflow tract tachycardia (RVOT) inferior of the pulmonary valve. Successful radiofrequency ablation was performed and the patient is still free from ventricular tachycardia.

Insular Cortex Lesions, Cardiac Troponin, and Detection of Previously Unknown Atrial Fibrillation in Acute Ischemic Stroke

Background and Purpose—

Detection rates of paroxysmal atrial fibrillation (AF) after acute ischemic stroke increase with duration of ECG monitoring. To date, it is unknown which patient group may benefit most from intensive monitoring strategies. Therefore, we aimed to identify predictors of previously unknown AF during in-hospital ECG monitoring.

Methods—

All consecutive patients with imaging-confirmed ischemic stroke admitted to our tertiary care hospital from February 2011 to December 2013 were registered prospectively. Patients received continuous bedside ECG monitoring for at least 24 hours. Detection of previously unknown AF during in-hospital ECG monitoring was obtained from medical records. Patients with AF on admission ECG or known history of AF were excluded from analysis.

Results—

Among 1228 patients (median age, 73 years; median National Institutes of Health Stroke Scale, 4; 43.4% women), previously unknown AF was detected in 114 (9.3%) during a median time of continuous ECG monitoring of 3 days (interquartile range, 2–4 days). Duration of monitoring ( P <0.01), older age ( P <0.01), history of hypertension ( P =0.03), insular cortex involvement ( P <0.01), and higher high-sensitivity cardiac troponin T ( P =0.04) on admission were independently associated with subsequent detection of AF in a multiple regression analysis. Addition of high-sensitivity cardiac troponin T, insular cortex stroke, or both to the CHADS2 score (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke [2P]) significantly improved c -statistics from 0.63 to 0.68 ( P =0.01), 0.70 ( P <0.01), and 0.72 ( P <0.001), respectively.

Conclusions—

Insular cortex involvement, higher admission high-sensitivity cardiac troponin T, older age, hypertension, and longer monitoring are associated with new detection of AF during in-hospital ECG monitoring. Patients with higher high-sensitivity cardiac troponin T or insular cortex involvement may be candidates for prolonged ECG monitoring.

[Cardiac resynchronisation with atrial sensing: Is it feasible?]

In this article the cases of two female patients with heart failure (functional class III) and an intrinsic complete left bundle branch block are reported. Both patients have had an implanted cardioverter defibrillator (ICD) connected to a VDD lead for primary prevention of sudden cardiac death. Atrial sensing was good/acceptable with a physiological frequency histogram and normal PQ time. A system upgrade to cardiac resynchronization therapy device (CRT) was planned. The VDD lead was directly connected to the Bivent ICD. The follow up showed stable measurements and a high biventricular pacing rate. Thus, usage of VDD leads for atrial sensing in CRT seems to be possible in a selected patient population.

Cost-effectiveness of paclitaxel-coated balloon angioplasty in patients with drug-eluting stent restenosis

BACKGROUND

The economic impact of drug-eluting stent (DES) in-stent restenosis (ISR) is substantial, highlighting the need for cost-effective treatment strategies.

HYPOTHESIS

Compared to plain old balloon angioplasty (POBA) or repeat DES implantation, drug-coated balloon (DCB) angioplasty is a cost-effective therapy for DES-ISR.

METHODS

A Markov state-transition model was used to compare DCB angioplasty with POBA and repeat DES implantation. Model input parameters were obtained from the literature, and the cost analysis was conducted from a German healthcare payer's perspective. Extensive sensitivity analyses were performed.

RESULTS

Initial procedure costs amounted to €3488 for DCB angioplasty and to €2782 for POBA. Over a 6-month time horizon, the DCB strategy was less costly (€4028 vs €4169) and more effective in terms of life-years (LYs) gained (0.497 versus 0.489) than POBA. The DES strategy incurred initial costs of €3167 and resulted in 0.494 LYs gained, at total costs of €4101 after a 6-month follow-up. Thus, DCB angioplasty was the least costly and most effective strategy. Base-case results were influenced mostly by initial procedure costs, target lesion revascularization rates, and the costs of dual antiplatelet therapy.

CONCLUSIONS

DCB angioplasty is a cost-effective treatment option for coronary DES-ISR. The higher initial costs of the DCB strategy compared to POBA or repeat DES implantation are offset by later cost savings.

Potential lifetime cost-effectiveness of catheter-based renal sympathetic denervation in patients with resistant hypertension

AIMS

Recent studies have demonstrated the safety and efficacy of catheter-based renal sympathetic denervation (RDN) for the treatment of resistant hypertension. We aimed to determine the cost-effectiveness of this approach separately for men and women of different ages.

METHODS AND RESULTS

A Markov state-transition model accounting for costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness was developed to compare RDN with best medical therapy (BMT) in patients with resistant hypertension. The model ran from age 30 to 100 years or death, with a cycle length of 1 year. The efficacy of RDN was modelled as a reduction in the risk of hypertension-related disease events and death. Analyses were conducted from a payer's perspective. Costs and QALYs were discounted at 3% annually. Both deterministic and probabilistic sensitivity analyses were performed. When compared with BMT, RDN gained 0.98 QALYs in men and 0.88 QALYs in women 60 years of age at an additional cost of €2589 and €2044, respectively. As the incremental cost-effectiveness ratios increased with patient age, RDN consistently yielded more QALYs at lower costs in lower age groups. Considering a willingness-to-pay threshold of €35 000/QALY, there was a 95% probability that RDN would remain cost-effective up to an age of 78 and 76 years in men and women, respectively. Cost-effectiveness was influenced mostly by the magnitude of effect of RDN on systolic blood pressure, the rate of RDN non-responders, and the procedure costs of RDN.

CONCLUSION

Renal sympathetic denervation is a cost-effective intervention for patients with resistant hypertension. Earlier treatment produces better cost-effectiveness ratios.

Abstract 319: Potential Lifetime Cost-Effectiveness of Catheter-Based Renal Sympathetic Denervation in Patients with Resistant Hypertension

Aims - Recent studies have demonstrated the safety and efficacy of catheter-based renal sympathetic denervation (RD) for the treatment of resistant hypertension. We aimed to determine the cost-effectiveness of this approach separately for men and women of different ages.

Methods and results - A Markov state-transition model accounting for costs, survival, quality of life, and incremental cost-effectiveness was developed to compare RD with best medical therapy (BMT). The model ran from age 30 to 100 years or death, with a Markov cycle length of 1 year. All patients entered the model with elevated systolic blood pressure (SBP, 180 mmHg), but free from prior cardiovascular disease (CVD) events. Patients could remain in this disease-free state or could have one of the following primary CVD events: myocardial infarction, angina, stroke or heart failure. After an event, patients transitioned into chronic disease states and/or could suffer from secondary CVD events. In the base case scenario, RD resulted in a sustained SBP reduction of 20 mmHg and in a corresponding relative risk reduction of adverse CVD events and death. The cost analysis was conducted from a health care payer perspective. Effectiveness was expressed as quality-adjusted life-years (QALY) gained. Costs and effects were discounted at 3% per annum, respectively. Deterministic and probabilistic sensitivity analyses were conducted to evaluate the robustness of the results. As compared with BMT, RD gained 0.99 QALYs in men and 0.91 QALYs in women 60 years of age at an additional cost of $3,265 and $2,594, respectively. As the incremental cost-effectiveness ratio increased with patient age, RD consistently yielded more QALYs at lower costs in lower age groups. Considering a willingness to pay threshold of $50,000/QALY, there was a 95% probability that RD would remain cost-effective up to an age of 82 and 80 years in men and women, respectively. Cost-effectiveness was influenced most by the extent of SBP lowering by RD, the rate of RD non-responders, and the costs associated with the RD procedure.

Conclusion - RD offers a cost-effective treatment option for the prevention of CVD events in patients with resistant hypertension. An earlier intervention produces better cost-effectiveness ratios.

[Magnetic resonance imaging and implantable cardiac devices. Current status and future perspectives of MR-compatible systems]

Conventional pacemakers and implantable cardioverter-defibrillators (ICD) have always been regarded as a contraindication to magnetic resonance imaging (MRI). MR-compatible systems represent a recent and particularly important innovation, since they will provide device patients with significantly improved access to MR examinations. However, the safe application of MR-compatible technology requires a detailed understanding of the strictly defined cardiologic and radiologic requirements and conditions that are to be adhered to before and during an MR examination. The present article gives an overview of problematic MR interactions with implanted devices, illustrates the most important aspects of MR-compatible pacemaker and ICD systems, analyzes their current clinical status, and offers a critical perspective.

Absent proximal right coronary artery with a fistula into the pulmonary vein

A 32-year-old woman was admitted with a third-degree atrioventricular block. A permanent pacemaker was implanted and the patient was discharged. One week later, the patient presented again with a sustained ventricular tachycardia. Coronary angiography and computed tomography imaging with three-dimensional reconstructions revealed the absence of the proximal part of the right coronary artery (RCA) with a fistula into the pulmonary vein. This is the first case describing an absent proximal RCA combined with a pulmonary vein fistula.

Unmasking of myopotential oversensing by an integrated bipolar defibrillator lead following AV node ablation

A 73-year-old man with nonischemic cardiomyopathy underwent catheter ablation of ventricular tachycardia that had resulted in frequent shocks from his implanted cardiac resynchronization therapy defibrillator (CRT-D). Coexisting atrial fibrillation required AV node ablation which rendered the patient pacemaker dependent. During follow-up, recurrent episodes of dizziness occurred caused by inhibition of pacing due to oversensing of pectoral muscle myopotentials. Surgical revision was performed and the intraoperative examination revealed an intact integrated bipolar defibrillator lead with appropriate connections to the CRT-D header. The placement of an additional pace/sense lead completely resolved the patient's symptoms and no further myopotential oversensing was recorded.

Iceman Survived due to Cooling Device

Although mild hypothermia treatment is part of the standard postresuscitation care today, no standard method for treatment of accidental severe hypothermia has been yet established. Different strategies including invasive and noninvasive methods have been described in the literature. We present the case of a 75-year-old man with accidental severe hypothermia (23°C) and demonstrate that using a surface cooling device with automatic controlled temperature feedback mechanism (ArcticSun2000 Medivance, Louisville, Colorado, USA) is an effective and safe method for controlled rewarming in this life-threatening setting.

Optimal fluoroscopic projections for angiographic imaging of the pulmonary vein ostia: lessons learned from the intraprocedural reconstruction of the left atrium and pulmonary veins

AIMS

Electrical isolation of the pulmonary veins (PVs) is the cornerstone of the ablative treatment of atrial fibrillation. Selective angiography of the PVs in standard fluoroscopic projections is often used for intraprocedural identification of PVs and their ostia. Variable spatial orientation and significant variability of PV anatomy are important limitations of this imaging approach.

METHODS AND RESULTS

Sixty patients undergoing a PV isolation procedure received intraprocedural rotational angiography and three-dimensional reconstruction of the left atrium (LA) and PVs. For each patient, 33 angiographic projections were independently evaluated [right anterior oblique (RAO) 80 degrees to left anterior oblique (LAO) 80 degrees, in steps of 5 degrees] by two physicians in order to identify the optimal projections of the PV ostia according to the following definition: Sagittal plane: (i) clear identification of both superior and inferior segments of the LA-PV junction and (ii) no overlapping between LA (and/or left atrial appendage) and PV ostium. Frontal plane: (i) clear identification of all four quadrants of the PV ostium and (ii) fluoroscopic angles at which the maximal horizontal ostial diameter is visualized. A successful reconstruction of the LA and all PVs was obtained in 58 (97%) patients. An optimal ostial projection in a sagittal plane was identified for all four PVs. The optimal ostial projection was RAO 5 degrees for the right superior PVs in 57 out of 58 patients (98%), RAO 55 degrees for the right inferior PVs in 54 out of 58 patients (93%), LAO 45 degrees for the left superior PVs in 46 out of 58 patients (80%), and LAO 60 degrees for the left inferior PVs in 48 out of 58 patients (83%). An optimal ostial projection in a frontal plane was identified only for the inferior PVs. The optimal ostial projection was LAO 40 degrees for the right inferior PVs in 55 out of 58 patients (95%) and RAO 45 degrees for the left inferior PVs in 51 out of 58 patients (88%).

CONCLUSION

If selective angiography is to be used to delineate anatomy and location of the PV ostia to guide PV isolation, different fluoroscopic projections are required for different PVs. The preselected RAO and LAO projections proposed in our study result in optimal angiographic projections of all PV ostia in at least one plane in the majority of patients.