Relationship between ICD implantation volume and treatment parameters of patients receiving an ICD with remote monitoring

BACKGROUND

Both highly specialized heart centres and less specialized hospitals care for patients with implantable ICDs/CRT-Ds with remote monitoring.

OBJECTIVE

To investigate potential differences in patient treatment according to centre's ICD implantation volume.

METHODS

Based on their 2012 ICD/CRT-D implantation volume, centres enrolled in the NORDIC ICD trial in Germany were assigned to one of three groups: high- (HV, n= 345), medium- (MV, n= 340) or low-volume (LV, n= 189).

RESULTS

The HV-centres had a significant higher CRT-D proportion (41.7%; LV: 36.5%; MV: 23.2%; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001), significant shorter median procedure duration (49 min; MV: 58 min; LV: 60 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) but significant longer median hospital stay (4 days; MV and LV: 3 days; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) compared to MV- and LV-centres. The X-ray exposure was shorter in MV/HV-centres (MV: 3.4 min; HV: 3.6 min; LV: 5.5 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001). Only 3.5% (LV: 2.6%; HV: 3.5%; MV: 4.1%) patients received at least one delivered inappropriate shock and 2.5% (HV: 2.0%; LV: 2.6%; MV: 2.9%) patients had withheld inappropriate ICD shocks without subsequent inappropriate shock delivery within 24.5 months of median follow-up.

CONCLUSION

Implantation volume-dependent differences were observed in the device selection, procedure duration and x-ray exposure duration. Remote monitoring in combination with adequate response pattern prevented imminent inappropriate shocks in all three groups.

REACT DX registry: Real world REACTion to atrial high rate episodes detected in implantable cardioverter-defibrillator recipients with a DX lead

BACKGROUND

Atrial fibrillation (AF) is associated with significant morbidity and is predicted by atrial high rate events. The early detection of AF is paramount to timely interventions to reduce the morbidity of AF. The DX ICD system combined with Home Monitoring® allows for continuous atrial rhythm monitoring without the need for a dedicated atrial lead.

OBJECTIVE

To establish the reaction to and timing of reactions to the detection of atrial high rate episodes (AHRE).

METHODS

A prospective cohort of DX ICD systems was followed up and the response to AHREs was collected and evaluated.

RESULTS

A total of 234 patients were enrolled; an AHRE ⩾ 6 min was detected in 13.7% of patients (n= 32) within a mean follow-up duration of 16 months. A high rate of oral anticoagulation (OAC) prescription was seen with the detection of AHREs in patients with a not-low risk CHA2DS2-VASc score. There was a delay in this prescription highlighting the potential to improve the timeliness of patient care in this group of patients.

CONCLUSIONS

The DX ICD system provides rapid and ongoing atrial rhythm monitoring such that physicians are rapidly aware of AHRE without the need for a dedicated atrial lead, but local protocols are needed to improve the response time of anti-coagulation prescription.

Atrial Fibrillation Burden and Clinical Outcomes in Heart Failure: The CASTLE-AF Trial

OBJECTIVES

This subanalysis of the CASTLE-AF (Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF) trial aimed to address the association between atrial fibrillation (AF) recurrence, AF burden, and hard clinical outcomes in heart failure (HF) patients with AF.

BACKGROUND

The CASTLE-AF trial demonstrated the benefit of CA compared to pharmacological treatment in decreasing mortality and CV hospitalizations in patients with AF and HFrEF. However, the impact of AF recurrence and AF burden after ablation on long-term treatment benefit remains unknown.

METHODS

The CASTLE-AF protocol randomized 363 patients with coexisting HF and AF in a multicenter prospective controlled fashion to catheter ablation (n = 179) versus pharmacological therapy (n = 184). Two hundred eighty patients were included in this subanalysis (as-treated), 128 of them underwent ablation and 152 received pharmacological treatment. All patients had implanted dual chamber or biventricular implantable defibrillators with activated home monitoring capabilities. The individual AF burden was calculated as the percentage of the atrial arrhythmia time per day.

RESULTS

AF burden at baseline was not predictive of the primary endpoint (p = 0.473) or all-cause mortality (p = 0.446). AF recurrence (defined as any episode >30 s) did not show any relationship with the primary endpoints of mortality and occurrence of HF, irrespective of the treatment arm. An AF burden below 50% after 6 months of catheter ablation, was associated with a significant decrease in primary composite outcome (hazard ratio [HR]: 0.33; 95% confidence interval [CI]: 0.15 to 0.71; p = 0.014) and all-cause mortality (HR: 0.23; 95% CI: 0.07 to 0.71; p = 0.031). The risk of the primary endpoint or mortality was directly related to a low (<50%) or high (≥50%) AF burden at 6 months post-ablation.

CONCLUSIONS

AF burden at 6 months was predictive of hard clinical outcomes in HF patients with AF. The first recurrent atrial tachyarrhythmia episode >30 s after ablation was not associated with improvement in mortality and hospitalization for HF. (Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF [CASTLE-AF]; NCT00643188).

Impact of Left Ventricular Function and Heart Failure Symptoms on Outcomes Post Ablation of Atrial Fibrillation in Heart Failure: CASTLE-AF Trial

BACKGROUND

Recent data demonstrate promising effects on left ventricular dysfunction and left ventricular ejection fraction (LVEF) improvement following ablation for atrial fibrillation (AF) in patients with heart failure. We sought to study the relationship between LVEF, New York Heart Association class on presentation, and the end points of mortality and heart failure admissions in the CASTLE-AF study (Catheter Ablation for Atrial Fibrillation With Heart Failure) population. Furthermore, predictors for LVEF improvement were examined.

METHODS

The CASTLE-AF patients with coexisting heart failure and AF (n=363) were randomized in a multicenter prospective controlled fashion to ablation (n=179) versus pharmacological therapy (n=184). Left ventricular function and New York Heart Association class were assessed at baseline (after randomization) and at each follow-up visit.

RESULTS

In the ablation arm, a significantly higher number of patients experienced an improvement in their LVEF to >35% at the end of the study (odds ratio, 2.17; P<0.001). Compared with the pharmacological therapy arm, both ablation patient groups with severe (<20%) or moderate/severe (≥20% and <35%) baseline LVEF had a significantly lower number of composite end points (hazard ratio [HR], 0.60; P=0.006), all-cause mortality (HR, 0.54; P=0.019), and cardiovascular hospitalizations (HR, 0.66; P=0.017). In the ablation group, New York Heart Association I/II patients at the time of treatment had the strongest improvement in clinical outcomes (primary end point: HR, 0.43; P<0.001; mortality: HR, 0.30; P=0.001).

CONCLUSIONS

Compared with pharmacological treatment, AF ablation was associated with a significant improvement in LVEF, independent from the severity of left ventricular dysfunction. AF ablation should be performed at early stages of the patient's heart failure symptoms.

Preventive or Deferred Ablation of Ventricular Tachycardia in Patients With Ischemic Cardiomyopathy and Implantable Defibrillator (BERLIN VT)

Background:

Catheter ablation for ventricular tachycardia (VT) reduces the recurrence of VT in patients with implantable cardioverter-defibrillators (ICDs). The appropriate timing of VT ablation and its effects on mortality and heart failure progression remain a matter of debate. In patients with life-threatening arrhythmias necessitating ICD implantation, we compared outcomes of preventive VT ablation (undertaken before ICD implantation to prevent ICD shocks for VT) and deferred ablation after 3 ICD shocks for VT.

Methods:

The BERLIN VT study (Preventive Ablation of Ventricular Tachycardia in Patients With Myocardial Infarction) was a prospective, open, parallel, randomized trial performed at 26 centers. Patients with stable ischemic cardiomyopathy, a left ventricular ejection fraction between 30% and 50%, and documented VT were randomly assigned 1:1 to a preventive or deferred ablation strategy. The primary outcome was a composite of all-cause death and unplanned hospitalization for either symptomatic ventricular arrhythmia or worsening heart failure. Secondary outcomes included sustained ventricular tachyarrhythmia and appropriate ICD therapy. We hypothesized that preventive ablation strategy would be superior to deferred ablation strategy in the intention-to-treat population.

Results:

During a mean follow-up of 396±284 days, the primary end point occurred in 25 (32.9%) of 76 patients in the preventive ablation group and 23 (27.7%) of 83 patients in the deferred ablation group (hazard ratio, 1.09 [95% CI, 0.62–1.92]; P =0.77). On the basis of prespecified criteria for interim analyses, the study was terminated early for futility. In the preventive versus deferred ablation group, 6 versus 2 patients died (7.9% versus 2.4%; P =0.18), 8 versus 2 patients were admitted for worsening heart failure (10.4% versus 2.3%; P =0.062), and 15 versus 21 patients were hospitalized for symptomatic ventricular arrhythmia (19.5% versus 25.3%; P =0.27). Among secondary outcomes, the proportions of patients with sustained ventricular tachyarrhythmia (39.7% versus 48.2%; P =0.050) and appropriate ICD therapy (34.2% versus 47.0%; P =0.020) were numerically reduced in the preventive ablation group.

Conclusions:

Preventive VT ablation before ICD implantation did not reduce mortality or hospitalization for arrhythmia or worsening heart failure during 1 year of follow-up compared with the deferred ablation strategy.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02501005.

Effects of ajmaline on contraction patterns of isolated rat gastric antrum and portal vein smooth muscle strips and on neurogenic relaxations of gastric fundus

Class-I-antiarrhythmics like ajmaline are known to alter smooth muscle function, which may cause alterations in gastrointestinal motility. The effects of ajmaline on isolated gastric and portal vein smooth muscle and the underlying mechanisms are unknown. We studied the effects of ajmaline on the contractile patterns of isolated preparations of gastric antrum and portal vein from Wistar rats. The organ bath technique was used to measure spontaneous or pharmacologically induced isometric contractions. Changes in force observed after application of ajmaline or under control conditions are reported as % of the amplitude of an initial K⁺-induced contraction. Electric field stimulation was used to study neurogenic relaxations of gastric fundus smooth muscle. Ajmaline increased the amplitude of spontaneous contractions of muscle strips (portal vein: control 31.1 ± 15.2%, with 100 μM ajmaline 76.6 ± 32.3%, n = 9, p < 0.01; gastric antrum: control 9.5 ± 1.6%, with 100 μM ajmaline 63.9 ± 9.96%, n = 14, p < 0.01). The frequency of spontaneous activity was reduced in portal vein, but not in gastric antrum strips. The effects of ajmaline were not blocked by tetrodotoxin, L-nitroarginine methyl ester, or atropine. Ajmaline abolished coordinated neurogenic relaxations triggered by electric field stimulation and partly reversed the inhibition of GA spontaneous activity caused by the gap junction blocker carbenoxolone. Ajmaline enhances the amplitude of spontaneous contractions in rat gastric and portal vein smooth muscle. This effect may be accompanied, but not caused by an inhibition of enteric neurotransmission. Enhanced syncytial coupling as indicated by its ability to antagonize the effects of carbenoxolone is likely to underlie the enhancement of contractility.

Catheter Ablation for Atrial Fibrillation with Heart Failure

BACKGROUND

Mortality and morbidity are higher among patients with atrial fibrillation and heart failure than among those with heart failure alone. Catheter ablation for atrial fibrillation has been proposed as a means of improving outcomes among patients with heart failure who are otherwise receiving appropriate treatment.

METHODS

We randomly assigned patients with symptomatic paroxysmal or persistent atrial fibrillation who did not have a response to antiarrhythmic drugs, had unacceptable side effects, or were unwilling to take these drugs to undergo either catheter ablation (179 patients) or medical therapy (rate or rhythm control) (184 patients) for atrial fibrillation in addition to guidelines-based therapy for heart failure. All the patients had New York Heart Association class II, III, or IV heart failure, a left ventricular ejection fraction of 35% or less, and an implanted defibrillator. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure.

RESULTS

After a median follow-up of 37.8 months, the primary composite end point occurred in significantly fewer patients in the ablation group than in the medical-therapy group (51 patients [28.5%] vs. 82 patients [44.6%]; hazard ratio, 0.62; 95% confidence interval [CI], 0.43 to 0.87; P=0.007). Significantly fewer patients in the ablation group died from any cause (24 [13.4%] vs. 46 [25.0%]; hazard ratio, 0.53; 95% CI, 0.32 to 0.86; P=0.01), were hospitalized for worsening heart failure (37 [20.7%] vs. 66 [35.9%]; hazard ratio, 0.56; 95% CI, 0.37 to 0.83; P=0.004), or died from cardiovascular causes (20 [11.2%] vs. 41 [22.3%]; hazard ratio, 0.49; 95% CI, 0.29 to 0.84; P=0.009).

CONCLUSIONS

Catheter ablation for atrial fibrillation in patients with heart failure was associated with a significantly lower rate of a composite end point of death from any cause or hospitalization for worsening heart failure than was medical therapy. (Funded by Biotronik; CASTLE-AF ClinicalTrials.gov number, NCT00643188 .).

Neointimal fibrotic lead encapsulation - Clinical challenges and demands for implantable cardiac electronic devices

Every tenth patient with a cardiac pacemaker or implantable cardioverter-defibrillator implanted is expected to have at least one lead problem in his lifetime. However, transvenous leads are often difficult to remove due to thrombotic obstruction or extensive neointimal fibrotic ingrowth. Despite its clinical significance, knowledge on lead-induced vascular fibrosis and neointimal lead encapsulation is sparse. Although leadless pacemakers are already available, their clinical operating range is limited. Therefore, lead/tissue interactions must be further improved in order to improve lead removals in particular. The published data on the coherences and issues related to lead associated vascular fibrosis and neointimal lead encapsulation are reviewed and discussed in this paper.

MR Imaging in Patients with Cardiac Pacemakers and Implantable Cardioverter Defibrillators

This joint consensus paper of the German Roentgen Society and the German Cardiac Society provides physical and electrophysiological background information and specific recommendations for the procedural management of patients with cardiac pacemakers (PM) and implantable cardioverter defibrillators (ICD) undergoing magnetic resonance (MR) imaging. The paper outlines the responsibilities of radiologists and cardiologists regarding patient education, indications, and monitoring with modification of MR sequences and PM/ICD reprogramming strategies being discussed in particular. The aim is to optimize patient safety and to improve legal clarity in order to facilitate the access of SM/ICD patients to MR imaging. Key Points:  · Conventional PM and ICD systems are no longer an absolute but rather a relative contraindication for performing an MR examination. Procedural management includes the assessment of the individual risk/benefit ratio, comprehensive patient informed consent about specific risks and "off label" use, extensive PM/ICD-related and MR-related safety precautions to reduce these risks to the greatest extent possible, as well as adequate monitoring techniques.. · MR conditional pacemaker and ICD systems have been tested and approved for MR examination under specific conditions ("in-label" use). Precise understanding of and compliance with the terms of use for the specific pacemaker system are essential for patient safety.. · The risk for an ICD patient during MR examinations is to be considered significantly higher compared to PM patients due to the higher vulnerability of the structurally damaged myocardium and the higher risk of irreversible damage to conventional ICD systems. The indication for a MR examination of an ICD patient should therefore be determined on a stricter basis and the expected risk/benefit ratio should be critically reviewed.. · This complex subject requires close collaboration between radiology and cardiology.. Citation Format · Sommer T, Bauer W, Fischbach K et al. MR Imaging in Patients with Cardiac Pacemakers and Implantable Cardioverter Defibrillators. Fortschr Röntgenstr 2017; 189: 204 - 217.

[Consensus statement: Management of oral anticoagulation for stroke prevention in patients with nonvalvular atrial fibrillation]

With the introduction of edoxaban last year in Germany, four nonvitamin K antagonist oral anticoagulants are now available for stroke prevention in patients with nonvalvular atrial fibrillation. These novel oral anticoagulants (NOAC) represent an attractive new option compared to vitamin K antagonists (e.g., warfarin or phenprocoumon) due to simple use and fewer interactions with other drugs or food. Therefore, no INR monitoring and dosage adjustments are required for NOAC. The compelling clinical advantage of NOAC is the dramatic risk reduction of hemorhagic stroke and intracranial bleeding compared to current standard. In addition, total mortality is significantly reduced by 10 %. These effects are demonstrated for all four NOAC (dabigatran, rivaroxaban, apixaban and edoxaban). Therefore, current national and international guidelines recommend NOAC as the preferred option or at least as an attractive alternative compared to the former standard of vitamin K antagonists. The economic impact and reimbursement by Statutory Health Insurance (GKV) is of major importance for treatment in an outpatient setting. For apixaban and edoxaban, an additional benefit was granted by the institution of G‑BA and IQWiG in this clinical setting, whereas dabigatran and rivaroxaban were not assessed due to market entrance prior to 2011 before the AMNOG procedure was initiated. The members of this consensus paper recommend NOAC as the preferred option for patients with nonvalvular atrial fibrillation who are currently not treated with anticoagulant drugs in spite of clear indication for anticoagulation. For new patients with nonvalvular fibrillation, it should be decided on an individual basis which treatment option is adequate for the patient with their respective comorbidities.

Adjunctive surgical atrial fibrillation ablation during cardiac surgery: real life experiences

AIM

Several tools have been invented for surgical atrial fibrillation (AF) ablation. In this study, we investigated the real world efficacy of intraoperative AF ablation (AFA) with radiofrequency-energy or cryo-ablation and performed an electro-anatomical remap in some patients with recurrences.

METHODS

Seventy-three consecutive patients (53 male, median age of 69 ± 7 years) with history of AF underwent cardiac surgery for valve repair (74 % mitral defects, 60 % aortic defects) and/or coronary artery bypass graft procedures (56 %). During a follow-up of 23 ± 11 months after AFA we performed intensified holter-monitoring (4-7 days). Patients with symptomatic relapse of atrial arrhythmias (AA) were offered the opportunity for additional electrophysiological examination (EPE).

RESULTS

During 23 ± 11 months after AFA, 45 patients (62 %) had recurrent AA. In eight patients we performed EPE. In all 8 cases, septal circumferential lesions could be demonstrated during mapping with discrete gaps. All lateral veins were isolated however, posteriorly deep inside the vein leaving the antral region completely untreated. Neither roof lines nor mitral isthmus lines were complete. Performing catheter ablation, all veins could be isolated and seven patients were free of any arrhythmias during follow up (9 ± 5 months) without taking antiarrhythmic drugs.

CONCLUSION

Surgical AF ablation may often be incomplete rendering sobering results in unselected patients. Completion of the ablation is feasible with catheter ablation with good clinical outcome.

Prevalence of atrial fibrillation in patients with high CHADS2- and CHA2DS2VASc-scores: anticoagulate or monitor high-risk patients?

Background

In patients with known atrial fibrillation (AF) different scores are utilized to estimate the risk of thromboembolic events and guide oral anticoagulation. Diagnosis of AF strongly depends on the duration of electrocardiogram monitoring. The aim of this study was to use established scores to predict the prevalence of AF.

Methods

The CHADS₂- (Congestive Heart failure, hypertension, Age >75 years, Diabetes, Stroke [doubled]) and CHA₂DS₂VASc-score (Congestive Heart failure, hypertension, Age ≥75 years [doubled], Diabetes, Stroke [doubled], Vascular disease, Age 65–74 years, Sex category [female sex]) was calculated in 150,408 consecutive patients, referred to the University Hospital of Rostock between 2007 and 2012. All factors constituting these scores and a history of AF were prospectively documented with the ICD-10 admission codes.

Results

Mean age of our study population was 67.6 ± 13.6 years with a mean CHADS₂-score of 1.65 ± 0.92 and CHA₂DS₂VASc-score of 3.04 ± 1.42. AF was prevalent in 15.9% of the participants. The prevalence of AF increased significantly with every CHADS₂- and CHA₂DS₂VASc-score point up to 54.2% in CHADS₂-score of 6 and 71.4% in CHA₂DS₂VASc-score of 9 (P < 0.001).

Conclusion

The prevalence of AF increases with increasing CHADS₂- and CHA₂DS₂VASc-score. In intermediate scores intensified monitoring may be recommended. In high scores, thromboembolic complications occurred irrespective of the presence of AF and anticoagulant therapy may be initiated irrespective of documented AF.

Exclusion of thrombocytopenia as a contraindication for invasive radiofrequency ablation in a patient with paroxysmal atrial fibrillation by using magnesium anticoagulation instead of EDTA: another case of anticoagulant-induced pseudo-thrombocytopenia

Thrombocytopenia might be an exclusion criterion for invasive radiofrequency catheter ablation; therefore it is necessary to differentiate between pseudo-thrombocytopenia and a low platelet count due to other etiologies.A 69-year-old female presented to the cardiology department with recurrent atrial fibrillation that was resistant to conventional drug treatment. The initial laboratory findings were within the normal ranges, except for low platelet counts that occurred without a specific bleeding history. The reason for thrombocytopenia was anticoagulant-induced in vitro aggregation of platelets in the presence of EDTA as well as in citrated blood samples. As recently communicated, magnesium anticoagulated blood samples prevent platelet aggregation in individuals with anticoagulant-associated pseudo-thrombocytopenia. Although its aggregation-inhibiting effect is known from previous clinical observations, magnesium sulphate has not been introduced as an anticoagulant in analytical medicine.Based on our observations, blood anticoagulated with magnesium sulphate is recommended to verify low routine platelet counts before final clinical decisions are made.

Intra-operative defibrillation testing and clinical shock efficacy in patients with implantable cardioverter-defibrillators: the NORDIC ICD randomized clinical trial

AIMS

This trial was designed to test the hypothesis that shock efficacy during follow-up is not impaired in patients implanted without defibrillation (DF) testing during first implantable cardioverter-defibrillator (ICD) implantation.

METHODS AND RESULTS

Between February 2011 and July 2013, 1077 patients were randomly assigned (1 : 1) to first time ICD implantation with (n = 540) or without (n = 537) DF testing. The intra-operative DF testing was standardized across all participating centres, and all ICD shocks were programmed to 40 J irrespective of DF test results. The primary end point was the average first shock efficacy (FSE) for all true ventricular tachycardia and fibrillation (VT/VF) episodes during follow-up. The secondary end points included procedural data, serious adverse events, and mortality. During a median follow-up of 22.8 months, the model-based FSE was found to be non-inferior in patients with an ICD implanted without a DF test, with a difference in FSE of 3.0% in favour of the no DF test [confidence interval (CI) -3.0 to 9.0%, Pnon-inferiority <0.001 for the pre-defined non-inferiority margin of -10%). A total of 112 procedure-related serious adverse events occurred within 30 days in 94 patients (17.6%) tested compared with 89 events in 74 patients (13.9%) not tested (P = 0.095).

CONCLUSION

Defibrillation efficacy during follow-up is not inferior in patients with a 40 J ICD implanted without DF testing. Defibrillation testing during first time ICD implantation should no longer be recommended for routine left-sided ICD implantation.

[Risk stratification of sudden cardiac death in dilated cardiomyopathy. Programmed ventricular stimulation]

There is a strong correlation between clinical presentation and results of the electrophysiological study (EPS) in patients with dilated cardiomyopathy. Patients with spontaneous ventricular tachycardia (VT) or syncope often have inducible VT in contrast to patients who have no history of arrhythmias or syncope. Therefore, the EPS is rather not useful for risk stratification but for planning of an adjuvant antiarrhythmic or ablation therapy. This is also true for patients with frequent ventricular extrasystole or nonsustained VT in whom VT may aggravate heart failure. An EP study may still be useful to differentiate between syncope of bradycardic or tachycardic origin.

The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial: concept and design of a randomized, controlled trial of intra-operative defibrillation testing during de novo defibrillator implantation

AIMS

Although defibrillation (DF) testing is still considered a standard procedure during implantable cardioverter-defibrillator (ICD) insertion and has been an essential element of all trials that demonstrated the survival benefit of ICD therapy, there are no large randomized clinical trials demonstrating that DF testing improves clinical outcome and if the outcome would remain the same by omitting DF testing.

METHODS AND RESULTS

Between February 2011 and July 2013, we randomly assigned 1077 patients to ICD implantation with (n = 540) or without (n = 537) DF testing. The intra-operative DF testing was standardized across all participating centres. After inducing a fast ventricular tachycardia (VT) with a heart rate ≥240 b.p.m. or ventricular fibrillation (VF) with a low-energy T-wave shock, DF was attempted with an initial 15 J shock. If the shock reversed the VT or VF, DF testing was considered successful and terminated. If unsuccessful, two effective 24 J shocks were administered. If DF was unsuccessful, the system was reconfigured and another DF testing was performed. An ICD shock energy of 40 J had to be programmed in all patients for treatment of spontaneous VT/VF episodes. The primary endpoint was the average efficacy of the first ICD shock for all true VT/VF episodes in each patient during follow-up. The secondary endpoints included the frequency of system revisions, total fluoroscopy, implantation time, procedural serious adverse events, and all-cause, cardiac, and arrhythmic mortality during follow-up. Home Monitoring was used in all patients to continuously monitor the system integrity, device programming and performance.

CONCLUSION

The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial is one of two large prospective randomized trials assessing the effect of DF testing omission during ICD implantation.

CLINICALTRIALSGOV IDENTIFIER

NCT01282918.

Spontaneous left atrial reentry tachycardias : radiofrequency ablation and outcome

AIMS

Spontaneous left atrial reentry tachycardias (LART) in patients without previous cardiac surgical or catheter ablation are rare. Several therapeutic concepts of catheter ablation have been suggested: linear lesions (LL), circumferential pulmonary vein isolation (PVI), and both (LL + PVI).

METHODS AND RESULTS

In all, 28 consecutive symptomatic patients with 51 LARTs presented to our institution for catheter ablation. Electroanatomical mapping was performed on 25 patients. Three patients were ablated conventionally during LART; 25 patients (89.3 %) had extensive low-voltage areas in the left atrium (atrial myopathy). One of the following ablation strategies was applied: first, LL (n = 8), second, PVI + LL (n = 11), and third PVI alone (n = 9). Fourteen patients (50 %) had a recurrent arrhythmia during a mean follow-up of 12.2 ± 11.1 months. Six patients presented with a recurrent LART (21.4 %), 4 with LART and atrial fibrillation (Afib) (14.3 %), and 4 with Afib (14.3 %). The recurrence rate of any arrhythmia (LART and Afib) was 37.5 % in the LL group, 44.4 % in the PVI group, and 63.6 % in the PVI + LL group (ns); the recurrence rate of LARTs was 12.5 % in the LL group, 22.2 % in the PVI group, and 63.6 % in the PVI + LL group (p < 0.05).

CONCLUSION

Atrial tachyarrhythmia recurrence after ablation of spontaneous LART in mid-term is considerable. Stable LARTs are effectively treated by LL. PVI alone may be an acceptable alternative, especially in patients with unstable LARTs and Afib. However, the risk of recurrent LARTs after a more extensive strategy with PVI and LL is considerable, probably due to proarrhythmic effects of long linear lesions.

Predictive factors for pacemaker requirement after transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been established as a treatment option for inoperable patients with symptomatic aortic valve stenosis. However, patients suffer frequently from conduction disturbances after TAVI.

Methods

Baseline, procedural as well as surface and intracardiac ECG parameters were evaluated for patients treated with TAVI and a comparison between patients requiring pacemaker with those not suffering from relevant conduction disorders were done.

Results

TAVI was successfully in all patients (n=45). Baseline surface and intracardiac ECG recording revealed longer PQ (197.1±51.2 msec versus 154.1±32.1 msec; p<0.001), longer AH (153.6±43.4 msec versus 116.1±31.2 msec; p<0.001) and HV interval (81.7±17.8 msec versus 56.8±8.5 msec; p<0.001) in patients with need for a pacemaker (n=23) versus control group (n=22); furthermore, 7-day follow-up analysis showed a higher prevalence of new left bundle branch block (LBBB) (87.0% versus 31.9%; p<0.001). Multivariate analysis revealed that only new LBBB, QRS duration >120 msec and a PQ interval >200 msec immediately (within 60 minutes) after implantation of the aortic valve were predictors for high-grade (type II second-degree and third-degree) AV block. Other clinical parameters as well as baseline electrocardiographic parameters had no impact on critical conduction delay.

Conclusion

Cardiac conduction disturbances are common after TAVI. The need for pacing after TAVI is predictable by surface ECG evaluation immediately (within 60 minutes) after the procedure.

Defibrillation Testing During Defibrillator Implantation

Implantable cardioverter defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy. ICDs improve mortality in patients after survived sudden cardiac death (SCD) and in patients at high risk of dying suddenly. All trials which show a benefit of ICD therapy, have performed some kind of defibrillation testing in order to prove correct system function, sensing of VF and effective defibrillation. Current devices show a shock efficacy of 80-90 % for singular shocks and devices provide up to seven rescue shocks. The probability that a device does not terminate an episode of VT or VF should therefore be very low. However, it is difficult to abandon defibrillation testing because prospective data is lacking that demonstrate non-inferiority, if ICDs are implanted without some kind of test. Two prospective trials are on the way and will be finish by 2013/14: the SIMPLE and NORDIC trial, which will answer the question if defibrillation testing can be abandoned without any effect on the benefit of ICD therapy or if testing may even be harmful.

[Recommendations of the Working Group of Arrhythmias of the German Society of Cardiology on the approach to patients with Riata® and Riata ST® leads (St. Jude Medical). Nucleus of the Working Group of Arrhythmias of the German Society of Cardiology]

Riata® and Riata ST® implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA) show an increased incidence of insulation defects, particularly "inside-out" lead fracture where inner, separately insulated cables penetrate through the surrounding silicone of the lead body. The exact incidence of Riata® lead problems is not clear and seems to range between 2-4% per year in the first 5 years after implantation according to new registry data. We recommend beyond a detailed information the following care of patients with Riata® and Riata ST® leads: 1) Activation of automatic ICD alerts, 2) remote monitoring with automatic daily alerts whenever possible, 3) monthly ICD controls in patients at high risk (pacemaker dependency, history of ventricular tachyarrhythmias) and high or moderate lead-related risk (8F, 7F single coil), 3-monthly controls in moderate patient and lead-related risk, 3 to 6-monthly controls in low patient and lead-related risk (no bradycardia, no history of ventricular tachyarrhythmia). Every ICD control should include meticulous analysis of oversensing artifacts in stored electrograms (EGMs) of sustained and non-sustained ventricular tachyarrhythmias and registration of EGMs during provocation testing (pectoral muscle activity, arm movements). If electrical abnormalities are observed, reoperation with addition of a new ICD lead is recommended; lead extraction only if indicated according to current guidelines. Fluoroscopy should only be performed if electrical abnormalities are found by an experienced electrophysiologist and a high frame rate and resolution. Management of fluoroscopic abnormalities in the absence of electrical abnormalities is not clear. Therefore, routine fluoroscopy of patients with Riata® leads without electrical abnormalities is not recommended.

A new single chamber implantable defibrillator with atrial sensing: a practical demonstration of sensing and ease of implantation

Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect patients from sudden cardiac death (SCD). However, inappropriate shocks may occur if tachycardias are misdiagnosed. Inappropriate shocks are harmful and impair patient quality of life. The risk of inappropriate therapy increases with lower detection rates programmed in the ICD. Single-chamber detection poses greater risks for misdiagnosis when compared with dual-chamber devices that have the benefit of additional atrial information. However, using a dual-chamber device merely for the sake of detection is generally not accepted, since the risks associated with the second electrode may outweigh the benefits of detection. Therefore, BIOTRONIK developed a ventricular lead called the Linox(SMART) S DX, which allows for the detection of atrial signals from two electrodes positioned at the atrial part of the ventricular electrode. This device contains two ring electrodes; one that contacts the atrial wall at the junction of the superior vena cava (SVC) and one positioned at the free floating part of the electrode in the atrium. The excellent signal quality can only be achieved by a special filter setting in the ICD (Lumax 540 and 740 VR-T DX, BIOTRONIK). Here, the ease of implantation of the system will be demonstrated.

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing.

Materials and methods

We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up.

Results

TAVI was performed successfully in all patients. During 7 days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p < 0.001), while rates for type II second- and third-degree were 0 versus 8% (p < 0.001) and 0 versus 12% (p < 0.001), respectively. Similarly, the prevalence of new left bundle branch block (LBBB) rose from 2 to 54% (p < 0.001). Intracardiac measurements revealed a prolongation of both AH and HV interval from 123.7 ± 41.6 to 136.6 ± 40.5 ms (p < 0.001) and from 54.8 ± 11.7 to 71.4 ± 20.0 ms (p < 0.001), respectively. Pacemaker implantation at a mean follow-up of 4.8 ± 1.2 days was subsequently performed in 23 patients (46%) due to complete AV block (12%) and type II second-degree AV block (8%) while another 13 patients (26%) received a pacemaker for the combination of new LBBB with marked HV prolongation. The high rate of first-degree AV block was primarily driven by an increase in HV interval.

Conclusion

Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1 week.

Ventricular tachycardia and sudden death after primary PCI-reperfusion therapy: impact on primary prevention of sudden cardiac death

BACKGROUND

Current approaches to coronary artery disease (CAD) and acute myocardial infarction (MI) may not be well represented in most primary prevention trials of sudden cardiac death (SCD).

METHODS

The contemporary and ongoing registry of the Rostock infarction network (Drip & Ship) represents a well-defined cohort of patients subjected to percutaneous coronary intervention (PCI) for ST-elevation infarction (STEMI) and served as the database for both candidates for an ICD for primary prevention of SCD and for sudden death (SCD) or ventricular tachycardia (VT) during follow-up.

RESULTS

A total of 855 consecutive patients were treated with PCI for STEMI or NSTEMI in the region of Rostock (Germany) between 2001 and 2004. While all cause mortality was still 17.2%, the SCD rate was low at 1.3% during 728 ± 366 days of follow-up. Within that time 85 patients (9.9%) developed an indication for ICD therapy due to an impaired LV function (LVEF ≤ 35%) and heart failure. Univariate predictors of an ICD indication were delayed reperfusion (p = 0.001), a high creatine kinase (CK) max (p = 0.009), a persistent wide QRS complex (p = 0.001), previous cerebrovascular events (p = 0.033), and chronic renal failure (p = 0. 001). However, only 16.5% of these patients qualifying for an ICD actually received an ICD; nevertheless, the actual SCD rate was only 3.5%, while 5.4% (46 patients) suffered VTs or ventricular fibrillation (VF). The SCD/VT rate in the entire infarct population was associated with time to reperfusion (0.032), left bundle-branch block (0.002), a longer history of CAD (0.032), and VT during follow-up.

CONCLUSION

While mortality in patients with STEMI is still alarming even with PCI, the risk of SCD may be considerably decreased even in patients with an LVEF below 35%. With the current approach to primary prevention of sudden cardiac death, approximately 10% of postinfarction patients qualify for ICD therapy; however this may only reach a quarter of patients prone to SCD.

[Antiarrhythmic therapy with β-receptor antagonists]

β-Blockers are an essential component of medical therapy in patients with ischemic heart disease or cardiac dysfunction of any genesis. They have an effect at the level of the sinus and the atrioventricular node, as well as on the atrial and ventricular refractory period of the myocardium. Overall, there are complicated antifibrillatory effects which are involved in the reduction of morbidity and mortality of this the therapy. According to the guidelines, it is important to uptitrate to highest tolerated dose. In patients with atrial fibrillation, antiadrenergic therapy should be the first line treatment; if well tolerated, then β-blockers alone or as a combination with an antiarrhythmic drug is preferable. Future prospective studies on the antiarrhythmic effects in this therapeutic area should include comparisons of different α - and β-selective active substances. Increasing knowledge of the differential therapy with the available active substances including intravenously applicable short-acting β-blockers, e.g., in intensive care therapy - should distinguish the different therapeutic effects.

[The patient with chronic heart failure]

An expansion of the indications for the implantation of defibrillators (ICD) has not occurred as such in recent years. Nevertheless, an increase in the number of implantation figures can be expected due to the aging population and an increasing recruitment of undersupplied regions in upcoming years. Although the first defibrillator was implanted over 20 years ago in Germany and that ICD therapy is considered as the medical standard in secondary and primary prophylaxis, there are still basic questions that can only be prospectively clarified: (1) when is the right point in time for ICD implantation? (2) Can predictors, especially those with a negative predictive value, be used to exclude patients from ICD therapy? (3) Should risk stratification, which documents the current risk for a single point in time during the illness like a snapshot, more strongly reflect the development over time of the risk? In this case, it is likely that a rethinking of risk stratification, in general, to risk stratification in the sense of observation would be necessary. An adjuvant therapy in the sense of ablation of ventricular tachycardia (VT) or antiarrhythmic therapy for primary prevention of frequently occurring episodes seems to be advised based on current data. However, the right point in time for a complementary intervention is still not clear.

[Quadricuspid aortic valve as an unusual cause of severe aortic regurgitation]

BACKGROUND

Both, acute and chronic aortic insufficiency, can be caused by various conditions. While the acute form is often associated with an endocarditis, type A aortic dissection and trauma, one possible cause of chronic aortic insufficiency is a congenital malformation of the aortic valve. Among these malformations, the quadricuspid aortic valve is the most rare form. The diagnosis is often made by Doppler echocardiography, during cardiac surgery, or postmortem.

CASE REPORT

A 44-year-old female patient presented with a 2-year history of increasing dyspnea on exertion. The physical examination revealed a diastolic heart murmur in the second right intercostal space and a blood pressure of 170/60 mmHg. Transthoracic and transesophageal Doppler echocardiography disclosed a quadricuspid aortic valve with severe aortic insufficiency. After implantation of a mechanical aortic valve, the patient was clinically well.

CONCLUSION

Quadricuspid aortic valve, often associated with aortic insufficiency, is a rare condition. The diagnosis can be made by Doppler echocardiography. The special treatment should be based on objective and subjective findings. In the absence of severe aortic regurgitation or clinical signs, a medical treatment with close follow-up is justified. In case of severe aortic regurgitation or clinical signs of cardiac decompensation, surgical treatment is recommended.

Evolution of cardiac autonomic nervous activity indices in patients presenting with transient left ventricular apical ballooning

BACKGROUND

Transient left ventricular (LV) apical ballooning (AB) is characterized by a rapidly reversible, acute LV systolic dysfunction, triggered by physical or emotional stress. Despite observations strongly suggesting catecholamine-mediated myocardial stunning due to enhanced sympathetic activity, the early time course of heart rate variability (HRV) has not been described.

METHODS

We prospectively enrolled 39 consecutive patients (median age = 68 years, range 35-85 years, 38 women) with LV AB. Indices of HRV were extracted from 24-hour ambulatory electrocardiograms on the day of hospital admission, on days 2 and 3, and 3 months after the hospitalization.

RESULTS

Within 48 hours after hospital admission, the indices of HRV were markedly depressed (standard deviation of normal-to-normal [NN] intervals [SDNN] 89.6 +/- 19.9 ms; mean standard deviation of NN intervals for 5-minute segments [SDNNi] 37.8 +/- 6.2 ms; root mean square of consecutive difference of normal-to-normal intervals [rMSSD] 23.0 +/- 9 ms; standard deviation of the averages of NN intervals for all 5-minute segments [SDANN] 70.1 +/- 18.0 ms; geometric triangular index [TI] 23.7 +/- 5.9 ms), recovered in the subacute phase and had normalized at 3 months follow-up (SDNN 124.7 +/- 24 ms; SDNNi 47.1 +/- 5.7 ms; rMSSD 31.1 +/- 10.5 ms; SDANN 118.5 +/- 27 ms; TI 31.2 +/- 8 ms; all P < 0.05). Mean RR-interval increased from 845 +/- 121 ms on day 1, to 929 +/- 84 ms at 3 months (P=0.06).

CONCLUSIONS

A marked depression of cardiac parasympathetic activity was observed in the acute phase of LV AB, followed by recovery of autonomic modulation between the subacute and the chronic phases. The rapid return of parasympathetic function may partially explain the favorable outcomes of patients presenting with LV AB.

Inducibility of atrial tachyarrhythmias after circumferential pulmonary vein isolation in patients with paroxysmal atrial fibrillation: clinical predictor and outcome during follow-up

Aims

We investigated the presence and clinical outcome of inducibility of atrial tachyarrhythmias after circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF).

Methods and results

Sixty patients with symptomatic PAF underwent CPVI guided by 3D mapping and double Lasso technique. After achievement of CPVI, the induction was performed. The left atrium (LA) volume and the isolated LA area around the right and left-sided pulmonary veins were measured by the 3D mapping system. Sustained atrial tachyarrhythmias (>10 min) were induced after CPVI in 17 of 60 patients (28%). Patients with inducible atrial tachyarrhythmias had significantly smaller isolated areas when compared with the group with non-inducible tachyarrhythmias (16.7 ± 2.3 vs. 18.8 ± 2.9%, P < 0.05). After the initial procedure, recurrence occurred in 18 of 43 (42%) patients in the non-inducible group and in 7 of 17 (41%) in the inducible group during follow-up. A repeat procedure was performed in all 25 patients with recurrence. Five patients had a recurrence after the repeat procedure during 20.8 ± 7.5 months, and there was no difference between the two groups.

Conclusion

Inducibility of atrial tachyarrhythmias is associated with proportionally smaller isolated area and does not predict the clinical efficacy of CPVI in patients with PAF.

Catheter-ablation of ventricular tachycardia in patients with coronary artery disease: influence of the endocardial substrate size on clinical outcome

Ablation of symptomatic ventricular tachycardia (VT) in patients with coronary artery disease is frequently performed using the three dimensional mapping system CARTO. In the amplitude map, bipolar potentials of <1.5 mV are considered abnormal and represent damaged myocardium due to previous infarction. This pathological electrical area can be arrhythmogenic, serving as the substrate for reentrant VT. The purpose of this study was to correlate the size of the endocardial substrate with the success of VT catheter ablation. Included in this retrospective analysis were 69 consecutive patients with coronary artery disease who underwent ablation for symptomatic clinical VT using CARTO. The voltage maps were analyzed and the area with abnormal bipolar electrograms (<1.5 mV) was determined using geometric approximation models. The area of abnormal electrograms was divided into three sizes: small (<or=15 cm(2); 11 patients), medium (16-99 cm(2); 50 patients), and large (>or=100 cm(2); 8 patients). Patient characteristics were not different between the three substrate groups in regard to age, tachycardia cycle length, or number of radiofrequency applications, however differed significantly between the small, medium and large group in regard to left ventricular ejection fraction (44 +/- 12% vs. 32 +/- 9% vs. 21 +/- 7%, respectively; P = 0.001). Overall, there was a significant correlation between myocardial infarction locations and endocardial substrate sizes (P = 0.031), such that 73% of small substrates were found after inferior myocardial infarctions, and 100% of large substrates after anterior and multiple myocardial infarctions (P = 0.003). After ablation, inducibility of ventricular arrhythmias was more rare in patients with small substrates compared to patients with medium or large substrates (small substrates: 9%, medium and large substrates: 43%, P = 0.043). Although during follow-up of 25 +/- 17 months (1 day to 72 months) there was no significant difference between endocardial substrate sizes in regard to recurrence rates (small: 27%, medium: 38%, large: 50%, P = 0.588), patients with a small substrate did not have fast VT or ventricular fibrillation (VF), in contrast to 30% and 38% of patients with medium and large substrates, respectively. We conclude that in patients with coronary artery disease a small area of low amplitude bipolar potentials (<or=15 cm(2)) was seen more often after inferior myocardial infarction than after anterior and multiple infarctions. After ablation, patients with small substrates were rarely inducible and showed a more benign course during follow-up (trend towards fewer arrhythmia recurrences and no fast VT or VF). As a result smaller arrhythmogenic substrates appear to be better amenable to catheter ablation than larger substrates.

The quick-implantable-defibrillator trial

AIMS

Earlier ICD therapy included an electrophysiological study (EPS), an extensive defibrillation threshold test (DFT), and a pre-discharge test. Now that ICD-therapy is widely accepted, an EPS is no longer performed in most patients, extensive DFT-tests have been reduced to a minimum of two effective shocks and discharge tests have been discarded in most centres. However, it has never been demonstrated prospectively that this simplification is safe.

METHODS AND RESULTS

The Quick-Implantable-Defibrillator (Quick-ICD) Trial was a prospective multi-centre trial, which randomized patients, who had survived a cardiac arrest (SCD) or an unstable ventricular tachycardia (VT), to two different clinical strategies: (a) The extensive strategy included an EPS, an extensive DFT-test, and a pre-discharge test; (b) In the simplified approach (quick strategy) the ICD was implanted without an EPS and a pre-discharge test. Two effective shocks during implantation at 21 J were sufficient. The primary endpoint of this trial was a cluster of adverse events related to the diagnostic approach and to ICD-therapy. One hundred and ninety patients were included, 97 randomized to the extensive-, 93 to the quick strategy. Mean follow-up was 12 +/- 7 months. Twenty-seven patients reached the endpoint in the quick group and 32 in the extensive group. During follow-up, the event-free survival was equal in the two study arms (test for equivalence, P = 0.0044). The initial hospital stay was significantly shorter in the quick population (8.4 +/- 4.7 vs. 11.2 +/- 7.4 days, P = 0.004)

CONCLUSION

It is safe and cost-effective to implant an ICD without an EPS, an extensive DFT-, and a pre-discharge test in carefully selected patients after survived SCD or unstable VTs.