Impact of a Chronic Total Coronary Occlusion on the Incidence of Appropriate Implantable Cardioverter-Defibrillator Shocks and Mortality: A Substudy of the Dutch Outcome in ICD Therapy (DO-IT)) Registry

BACKGROUND

Chronic total coronary occlusions (CTO) substantially increase the risk for sudden cardiac death. Among patients with chronic ischemic heart disease at risk for sudden cardiac death, an implantable cardioverter defibrillator (ICD) is the favored therapy for primary prevention of sudden cardiac death. This study sought to investigate the impact of CTOs on the risk for appropriate ICD shocks and mortality within a nationwide prospective cohort.

METHODS AND RESULTS

This is a subanalysis of the nationwide Dutch-Outcome in ICD Therapy (DO-IT) registry of primary prevention ICD recipients in The Netherlands between September 2014 and June 2016 (n=1442). We identified patients with chronic ischemic heart disease (n=663) and assessed available coronary angiograms for CTO presence (n=415). Patients with revascularized CTOs were excluded (n=79). The primary end point was the composite of all-cause mortality and appropriate ICD shocks. Clinical follow-up was conducted for at least 2 years. A total of 336 patients were included, with an average age of 67±9 years, and 20.5% was female (n=69). An unrevascularized CTO was identified in 110 patients (32.7%). During a median follow-up period of 27 months (interquartile range, 24-32), the primary end point occurred in 21.1% of patients with CTO (n=23) compared with 11.9% in patients without CTO (n=27; P=0.034). Corrected for baseline characteristics including left ventricular ejection fraction, and the presence of a CTO was an independent predictor for the primary end point (hazard ratio, 1.82 [95% CI, 1.03-3.22]; P=0.038).

CONCLUSIONS

Within this nationwide prospective registry of primary prevention ICD recipients, the presence of an unrevascularized CTO was an independent predictor for the composite outcome of all-cause mortality and appropriate ICD shocks.

Development and external validation of prediction models to predict implantable cardioverter-defibrillator efficacy in primary prevention of sudden cardiac death

Aims

This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation.

Methods and results

We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1–2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0–3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality.

Conclusion

Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed.

Five year outcomes of the subcutaneous implantable cardioverter-defibrillator EFFORTLESS (evaluation of factors impacting clinical outcome and cost effectiveness of the S-ICD) registry

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Boston Scientific

OnBehalf

EFFORTLESS Registry

Introduction

Patients (pts) implanted with transvenous (TV) implantable cardioverter-defibrillator (ICD) experience complications (Cx) associated with TV leads and inappropriate shocks (IAS) for atrial fibrillation (AF) or other supraventricular tachycardias (SVT). The EFFORTLESS S-ICD Registry is a 5-year (yr) follow-up (f/u) study of pts implanted with the subcutaneous ICD (S-ICD).

Purpose

To report on the 5-yr outcomes of pts with a wide range of S-ICD indications implanted with early generation devices.

Methods

Pts were enrolled at 43 centers February 2011-December 2014. Kaplan-Meier Cx, appropriate shock (AS), and IAS rates are reported.

Results

994 pts (495 retrospective) were enrolled in the EFFORTLESS study and 984 pts (28% female, 48 ± 17 yrs, BMI 27 ± 6 kg/m2, ejection fraction 43 ± 18%) underwent S-ICD implantation. Mean study f/u was 4.4 ± 1.6 yrs. The pt cohort had diverse etiologies: 31% ischemic heart disease, 19% non-ischemic cardiomyopathy, 11% hypertrophic cardiomyopathy, 17% channelopathies, and 20% of pts miscellaneous. Total system- and procedure-related Cx (table) were 9.4% at 5 yrs. AS and IAS rates at 5 yrs were 15.9% and 16.9%, respectively and the IAS rates for AF/SVT and t wave oversensing were 3.1% and 5.8%, respectively. More pts experienced Cx and IAS in the first yr than in yrs 2-5 altogether (8.7 vs 8.2%), the most common as a result of discomfort/erosion (38%), IAS (26%), system infection (9%), and premature battery depletion (9%). Of these late Cx, 74% were experienced by retrospective pts. Spontaneous conversion efficacy for the first shock and final shocks was 89.7% and 97.7%. Of the 91 (9.2%) deaths reported, none were associated with the S-ICD system or procedure. Cause of death was cardiac for 40 pts, non-cardiac for 40 pts, other for 4 pts, and unknown for 7 pts. Only 20 (2.0%) pts had their S-ICD replaced for a TV device for pacing: 4 bradycardia, 7 anti-tachycardia, and 9 for biventricular pacing.

Conclusions

The EFFORTLESS registry provides 5-year follow-up for a diverse, large, multinational S-ICD registry. Complications primarily occurred in the first year but remained low through 5 years. Inappropriate shock rates were typically observed in older generation devices prior to introduction of the SMART Pass filter. Replacement for TV-ICD due to the need for pacing was rare. Outcome 30 day 1 yr 2 yr 3 yr 4 yr 5yr Annual Complications (Kaplan-Meier) 2.0 5.3 6.8 7.6 8.6 9.4 1.9 IAS, overall (Kaplan-Meier) 1.7 8.7 11.6 13.1 14.6 16.9 3.4 IAS, t wave oversensing 3.4 5.8 1.2

Effect of remote monitoring on patient-reported outcomes in European heart failure patients with an implantable cardioverter-defibrillator: primary results of the REMOTE-CIED randomized trial

AIMS

The European REMOTE-CIED study is the first randomized trial primarily designed to evaluate the effect of remote patient monitoring (RPM) on patient-reported outcomes in the first 2 years after implantation of an implantable cardioverter-defibrillator (ICD).

METHODS AND RESULTS

The sample consisted of 595 European heart failure patients implanted with an ICD compatible with the Boston Scientific LATITUDE® RPM system. Patients were randomized to RPM plus a yearly in-clinic ICD check-up vs. 3-6-month in-clinic check-ups alone. At five points during the 2-year follow-up, patients completed questionnaires including the Kansas City Cardiomyopathy Questionnaire and Florida Patient Acceptance Survey (FPAS) to assess their heart failure-specific health status and ICD acceptance, respectively. Information on clinical status was obtained from patients' medical records. Linear regression models were used to compare scores between groups over time. Intention-to-treat and per-protocol analyses showed no significant group differences in patients' health status and ICD acceptance (subscale) scores (all Ps > 0.05). Exploratory subgroup analyses indicated a temporary improvement in device acceptance (FPAS total score) at 6-month follow-up for secondary prophylactic in-clinic patients only (P < 0.001). No other significant subgroup differences were observed.

CONCLUSION

Large clinical trials have indicated that RPM can safely and effectively replace most in-clinic check-ups of ICD patients. The REMOTE-CIED trial results show that patient-reported health status and ICD acceptance do not differ between patients on RPM and patients receiving in-clinic check-ups alone in the first 2 years after ICD implantation.ClinicalTrials.gov Identifier: NCT01691586.

High incidence of (ultra)low oesophageal temperatures during cryoballoon pulmonary vein isolation for atrial fibrillation

Background

Low oesophageal temperatures (OTs) during cryoballoon pulmonary vein isolation (PVI) have been associated with complications. This study assessed the incidence of low OT in clinical practice during cryoballoon PVI and verified possible predictive values for low OT.

Methods

Consecutive patients who underwent PVI using the second-generation cryoballoon were retrospectively included. The distance from the oesophagus to the different pulmonary veins (PVs) (OP distance), body mass index (BMI), sex, age, balloon temperature and application time were studied as potential predictors of low OTs. Computed tomography was performed before the procedure to determine the OP distance. OT was measured using an oesophageal temperature probe. Applications were ended prematurely if the OT reached <16 °C. Low and ultralow OT were defined as OT <20 and <16 °C respectively.

Results

Two hundred and four patients were included. Low OT was observed in 54 patients (26%) and 27 patients (13%) reached ultralow OTs. OP distance was the only predictor of low OTs after multivariate analysis. A cut-off value of 19 mm showed 96.2% sensitivity and 37.8% specificity in predicting low OTs. No clinically relevant relation was found between low OTs and BMI, age, sex, balloon temperature or application duration.

Conclusions

The incidence of low OT was 26% for cryoballoon PVI. OP distance was the only predictor of low OTs. Since an OP distance <19 mm was present in all patients in at least one PV, we recommend routine OT measurement during PVI cryoballoon therapy to prevent oesophagus-related complications.

Shorter RSPV cryoapplications result in less phrenic nerve injury and similar 1-year freedom from atrial fibrillation

BACKGROUND

In the 123-study, we prospectively assessed, in a randomized fashion, the minimal cryoballoon application time necessary to achieve pulmonary vein (PV) isolation (PVI) in patients with paroxysmal atrial fibrillation (AF) with the aim to reduce complications by shortening the application duration. The first results of this study demonstrated that shortened cryoballoon applications (<2 minutes) resulted in less phrenic nerve injury (PNI) without compromising acute isolation efficacy for the right PVs. We now report the 1-year follow-up results regarding safety and efficacy of shorter cryoballoon applications.

METHODS

A total of 222 patients with AF were randomized to two applications of 1 min "short," 2 min "medium," or 3 min "long" duration, 74 per group. Recurrence of AF and PV reconduction at 1-year follow-up were assessed.

RESULTS

The overall 1-year freedom from AF was 79% and did not differ significantly between the short, medium, and long application groups (77%, 74%, and 85% for short, medium, and long application groups, respectively; P = 0.07). In 30 patients, a redo PVI procedure was performed. For all four PVs, there was no significant difference in reconduction between the three groups. Reconduction was most common in the left superior PV (57%). The right superior PV (RSPV) showed significantly less reconduction (17%) compared to the other PVs.

CONCLUSIONS

Shortening cryoballoon applications of the RSPV to <2 minutes results in less PNI, while acute success and 1-year freedom from AF are not compromised. Therefore, shorter cryoballoon applications (especially) in the RSPV could be used to reduce PNI.

Incidence and predictors of implantable cardioverter-defibrillator therapy and its complications in idiopathic ventricular fibrillation patients

Aims

Idiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac arrest. Implantable cardioverter-defibrillator (ICD) implantation is currently the only treatment option. Limited data are available on the prevalence and complications of ICD therapy in these patients. We sought to investigate ICD therapy and its complications in patients with IVF.

Methods and results

Patients were selected from a national registry of IVF patients. Patients in whom no underlying diagnosis was found during follow-up were eligible for inclusion. Recurrence of ventricular arrhythmia (VA) was derived from medical and ICD records, electrogram records of ICD therapies were used to differentiate between appropriate or inappropriate interventions. Independent predictors for appropriate ICD shock were calculated using cox regression. In 217 IVF patients, recurrence of sustained VAs occurred in 66 patients (30%) during a median follow-up period of 6.1 years. Ten patients died (4.6%). Thirty-eight patients (17.5%) experienced inappropriate ICD therapy, and 32 patients (14.7%) had device-related complications. Symptoms before cardiac arrest [hazard ratio (HR): 2.51, 95% confidence interval (CI): 1.48–4.24], signs of conduction disease (HR: 2.27, 95% CI: 1.15–4.47), and carrier of the DPP6 risk haplotype (HR: 3.24, 1.70–6.17) were identified as independent predictors of appropriate shock occurrence.

Conclusion

Implantable cardioverter-defibrillator therapy is an effective treatment in IVF, treating recurrences of potentially lethal VAs in approximately one-third of patients during long-term follow-up. However, device-related complications and inappropriate shocks were also frequent. We found significant predictors for appropriate ICD therapy. This may imply that these patients require additional management to prevent recurrent events.

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Background

The second‐generation cryoballoon significantly improves outcome of pulmonary vein isolation (PVI) but may cause more complications than the first generation. Currently, no consensus regarding optimal cryoballoon application time exists. The 123‐study aimed to assess the minimal cryoballoon application duration necessary to achieve PVI (primary endpoint) and the effect of application duration on prevention of phrenic nerve injury (PNI).

Methods

Patients <75 years of age with paroxysmal atrial fibrillation, normal PV anatomy, and left atrial size <40 cc/m² or <50 mm were randomized to two applications of different duration: “short,” “medium,” or “long.” A total of 222 patients were enrolled, 74 per group.

Results

Duration per application was 105 (101‐108), 164 (160‐168), and 224 (219‐226) s and isolation was achieved in 79, 89, and 90% (P < 0.001) of the PVs after two applications in groups short, medium, and long, respectively. Only for the left PVs, the success rate of the short group was significantly less compared to the medium‐ and long‐duration groups (P < 0.001). PNI during the procedure occurred in 19 PVs (6.5%) in the medium and in 20 PVs (6.8%) in the long duration groups compared to only five PVs (1.7%) in the short duration group (P < 0.001).

Conclusions

Short cryoballoon ablation application times, less than 2 min, did affect the success for the left PVs but not for the right PVs and resulted in less PNI. A PV tailored approach with shorter application times for the right PVs might be advocated.

Use of three-dimensional computed tomography overlay for real-time cryoballoon ablation in atrial fibrillation reduces radiation dose and contrast dye

AIMS

Cryoballoon pulmonary vein (PV) isolation in patients with atrial fibrillation has proven to be effective in short-term and long-term follow-up. To visualise the PV anatomy, pre-ablation contrast pulmonary venography is commonly performed. Three-dimensional (3D) computed tomography (CT) overlay is a new technique creating a live 3D image of the left atrium by integrating a previously obtained CT scan during fluoroscopy. To evaluate the benefits of 3D CT overlay during cryoballoon ablation, we studied the use of 3D CT overlay versus contrast pulmonary venography in a randomised fashion in patients with paroxysmal atrial fibrillation undergoing cryoballoon PV isolation.

METHODS AND RESULTS

Between October 2012 and June 2013, 30 patients accepted for PV isolation were randomised to cryoballoon PV isolation using either 3D CT overlay or contrast pulmonary venography. All patients underwent a pre-procedural cardiac CT for evaluation of the anatomy of the left atrium (LA) and the PVs. In the 3D CT overlay group, a 3D reconstruction of the LA and PVs was made. An overlay of the CT reconstruction was then projected over live fluoroscopy. Patients in the contrast pulmonary venography group received significantly more contrast agent (77.1 ± 21.2 cc vs 40.1 ± 17.6 cc, p < 0.001) and radiation (43.0 ± 21.9 Gy.cm2 vs 28.41 ± 11.7 Gy.cm2, p = 0.04) than subjects in the 3D CT overlay group. There was no difference in total procedure time, fluoroscopy time and the amount of cryoapplications between the two groups.

CONCLUSION

The use of 3D CT overlay decreases radiation and contrast dye exposure and can assist in guiding cryoballoon-based PV isolation.

Long-term results of surgical minimally invasive pulmonary vein isolation for paroxysmal lone atrial fibrillation

AIMS

Transcatheter pulmonary vein ablation is the current treatment of choice for symptomatic drug-refractory atrial fibrillation (AF). Video-assisted surgical pulmonary vein isolation (sPVI) is an alternative therapy to percutaneous ablation for the treatment of AF. Long-term results of sPVI are currently unknown. The aim of this study was to report on the long-term efficacy and safety of sPVI in patients with paroxysmal AF.

METHODS AND RESULTS

The study design was observational and retrospective. From July 2005 to January 2011, 42 patients with drug-refractory paroxysmal AF underwent video-assisted sPVI in two different centres. Patients were eligible for sPVI when suffering from symptomatic, drug-refractory paroxysmal AF and they agreed to the alternative of sPVI. The median preoperative AF duration was 24 months (range 3-200). Success was defined as the absence of AF on 24 h or 96 h Holter monitoring during follow-up, off antiarrhythmic drugs (AAD). Adverse events and follow-up monitoring were based on the Heart Rhythm Society Consensus Statement 2012 for the catheter and surgical ablation of AF. Mean age was 55 ± 10 years, and 76% were males. After a mean follow-up of 5 years (SD 1.7), 69% of all patients were free from atrial arrhythmias without the use of AAD, and 83% with the use of AAD. Major peri-procedural adverse events occurred in four (9.5%) patients, no strokes or mortalities were registered during long-term follow-up.

CONCLUSION

This retrospective study shows that sPVI for the treatment of paroxysmal AF is effective and that the outcomes are maintained at long-term follow-up.

Prognostic value of microvolt T-wave alternans in a real-world ICD population. Twente ICD Cohort Studie (TICS)

Introduction

Survival benefit from ICD implantation is relatively low in primary prevention patients. Better patient selection is important to maintain maximum survival benefit while reducing the number of unnecessary implants. Microvolt T-wave alternans (MTWA) is a promising risk marker. In this study, we aimed to evaluate the predictive value of MTWA in ICD patients.

Methods and results

This study was a substudy of the Twente ICD Cohort Study (TICS). Patients with ischaemic or non-ischaemic left ventricular dysfunction who received an ICD following current ESC guidelines were eligible for inclusion. Exercise-MTWA was performed and classified as non-negative or negative. The primary endpoint was the composite of mortality and appropriate shock therapy. Analysis was performed in 134 patients (81 % male, mean age 62 years, mean ejection fraction 26.5 %). MTWA was non-negative in 64 %. There was no relation between non-negative MTWA testing and mortality and/or appropriate shock therapy (all p-values >0.15). Due to clinical conditions, 24 % were ineligible for testing. These patients experienced the highest risk for mortality (p < 0.01).

Conclusion

Non-negative MTWA testing did not predict mortality and/or appropriate shock therapy. Furthermore, MTWA testing is not feasible in a large percentage of patients. These ineligible patients experience the highest risk for mortality.

Surgical Minimally Invasive Pulmonary Vein Isolation for Lone Atrial Fibrillation

Objective

Minimally invasive surgical pulmonary vein isolation (SMI-PVI) is an emerging therapy for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Nevertheless, the midterm and long-term results of SMI-PVI remain unknown. The aim of this retrospective multicenter study was to report on midterm efficacy and safety of SMI-PVI.

Methods

The study design was retrospective, multicentric, and observational. From July 2005 to November 2011, a total of 86 patients with drug-refractory paroxysmal or persistent AF underwent SMI-PVI in three centers. Patients were eligible for SMI-PVI if they had symptomatic, drug-refractory AF or after failed transcatheter pulmonary vein isolation. Success was defined as absence of AF on 24- or 96-hour Holter monitoring during follow-up, in the absence of antiarrhythmic drugs (AADs).

Results

The mean ± SD age was 54 ± 11 years, and 78% were men. The median AF duration was 30 months (range, 2–203); paroxysmal AF was present in 86% of the patients, persistent in 14%. Fifteen patients (17%) underwent previous transcatheter ablations. After a median follow-up of 24 months (range, 6–78), 72% of all patients were free from atrial arrhythmias without the use of AADs. With AADs, this was 83%. Major perioperative adverse events occurred in 7 patients (8%).

Conclusions

This retrospective multicenter study shows that SMI-PVI is effective at a median follow-up of 24 months for the treatment of mostly paroxysmal drug-refractory AF. Perioperative adverse events do remain a point of caution.

Performance of an external transtelephonic loop recorder for automated detection of paroxysmal atrial fibrillation

BACKGROUND

Although atrial fibrillation (AF) is the most commonly encountered arrhythmia, some of the properties make its detection challenging. In daily practice, underdiagnosis can lead to less effective treatment in prevention of stroke. Based on data from studies on treatment of AF, more intensive follow-up strategies, including 7-day Holter recording, 30-day event recording, and even implantable cardiac monitoring devices, are suggested. The study purpose is to evaluate the performance of a continuous single-channel loop recorder with automatic AF detection and transtelephonic electrocardiogram (ECG) transmission capabilities.

METHODS AND RESULTS

A consecutive cohort of 153 patients admitted to the stroke unit with a presumptive diagnosis of ischemic cerebrovascular accident was screened for AF. Twenty-four-hour rhythm observation was performed using a single-channel external loop recorder (ELR) configured for automated AF detection. A total of 45 patients with a known history of AF, AF on the admission ECG, or incomplete registrations were excluded. Extensive additional frequency-based settings were used to establish a reference registration. In total, 2923 recordings were transmitted. We evaluated all events, of which 1190 were designated by the device as AF. The sensitivity, specificity, PPV, and NPV for identifying AF using the ELR were, respectively, 93%, 51%, 5%, and 99%.

CONCLUSIONS

In this ELR validation study, the dedicated AF detection algorithm showed to be highly sensitive but not specific for AF. Applicability of an ELR might be limited for efficacious detection of AF, as manual verification is mandatory for a vast amount of recordings.

Optimisation of cardiac resynchronization therapy in clinical practice during exercise

Aims

Although cardiac resynchronisation therapy (CRT) is an established treatment to improve cardiac function, a significant amount of patients do not experience noticeable improvement in their cardiac function. Optimal timing of the delay between atrial and ventricular pacing pulses (AV delay) is of major importance for effective CRT treatment and this optimum may differ between resting and exercise conditions. In this study the feasibility of haemodynamic measurements by the non-invasive finger plethysmographic method (Nexfin) was used to optimise the AV delay during exercise.

Methods and results

Thirty-one patients implanted with a CRT device in the last 4 years participated in the study. During rest and in exercise, stroke volume (SV) was measured using the Nexfin device for several AV delays. The optimal AV delay at rest and in exercise was determined using the least squares estimates (LSE) method. Optimisation created a clinically significant improvement in SV of 10 %. The relation between HR and the optimal AV delay was patient dependent.

Conclusion

A potential increase in SV of 10 % can be achieved using Nexfin for optimisation of AV delay during exercise. A considerable number of patients showed benefit with lengthening of the AV delay during exercise.

Is T-wave alternans testing feasible in candidates for prophylactic implantable defibrillators?

AIMS

Previous studies have demonstrated that microvolt T-wave alternans (TWA) screening in patients with ischaemic and dilated cardiomyopathy is effective in identifying patients at high or low risk of sudden cardiac death. It remains unclear which percentage of potential recipients of an implantable cardioverter defibrillator (ICD) are able to perform TWA testing using an exercise protocol which is, at this moment, the golden standard. In this study, we evaluated the feasibility of TWA in the risk stratification of potential ICD recipients with ischaemic or dilated cardiomyopathy.

METHODS AND RESULTS

Medical charts of 165 primary prevention ICD recipients were reviewed to decide if patients were able to perform a TWA exercise test or not. Reasons to waiver a test were: atrial fibrillation or flutter, pacemaker dependency, recent (cardiovascular) surgery (<1 month) and inability to exercise. Of the potential ICD recipients 35% had one or more of these contraindications and were therefore not suitable for testing.

CONCLUSION

In several studies, TWA is a promising risk stratifier for predicting sudden cardiac death; however, in our population, 35% of the potential ICD candidates could not be tested. In order to fulfil its promise as a predictor for SCD, an alternative means to measure TWA needs to be evaluated.

Incidence and predictors of phantom shocks in implantable cardioverter defibrillator recipients

BACKGROUND

Implantable cardioverter defibrillators (ICDs) are designed to deliver shocks or antitachycardia pacing (ATP) in the event of ventricular arrhythmias. During follow-up, some ICD recipients experience the sensation of ICD discharge in the absence of an actual discharge (phantom shock). The aim of this study was to evaluate the incidence and predictors of phantom shocks in ICD recipients.

METHODS

Medical records of 629 consecutive patients with ischaemic or dilated cardiomyopathy and prior ICD implantation were studied.

RESULTS

With a median follow-up of 35 months, phantom shocks were reported by 5.1 % of ICD recipients (5.7 % in the primary prevention group and 3.7 % for the secondary prevention group; p=NS). In the combined group of primary and secondary prevention, there were no significant predictors of the occurrence of phantom shocks. However, in the primary prevention group, phantom shocks were related to a history of atrial fibrillation (p=0.03) and NYHA class <III (p=0.05). In the secondary prevention group, there were no significant predictors for phantom shocks.

CONCLUSION

Phantom shocks occur in approximately 5 % of all ICD recipients. In primary prevention patients, a relation with a history of atrial fibrillation and NYHA class <III were significant predictors for the occurrence of phantom shocks. In the secondary prevention patients, no significant predictors were found.

Continuation of vitamin K antagonists as acceptable anticoagulation regimen in patients undergoing pulmonary vein isolation

BACKGROUND

Recent studies have demonstrated that radiofrequency isolation of the pulmonary veins (PVI) is an effective treatment for symptomatic atrial fibrillation. Based on these positive results, non- pharmacological therapy has been incorporated in the guidelines for drug refractory atrial fibrillation, resulting in an increased popularity. The prevention of thromboembolic complications remains an important issue.

METHODS

In January 2010, we adopted an anticoagulation strategy based on continuation of vitamin K antagonists (VKAs) and selective use of transoesophageal echocardiogram (TEE). We retrospectively analysed the results of this strategy in all patients referred for PVI treatment. VKAs were started for all patients 2 months prior to treatment. Discontinuation of oral anticoagulation was considered 3 months after treatment based on thromboembolic and bleeding risk profile. Bleeding and thromboembolic complications were registered during outpatient clinic follow-up up until 3 months.

RESULTS

We performed 151 PVI procedures from January 2010 to March 2011. All patients were seen 6 weeks after discharge. No transient ischaemic accidents or ischaemic cerebrovascular incidents occurred pre-, peri- or postprocedure. Four (2.7%) procedures were complicated by tamponade requiring pericardiocentesis.

CONCLUSIONS

Our data support the increasing evidence for continuation of periprocedural administration of VKAs complemented by a selective TEE approach as a safe therapy for thromboembolic complications.

Conductor externalization of the Riata internal cardioverter defibrillator lead: tip of the iceberg? Report of three cases and review of literature

AIMS

Recently, concerns about St Jude's Riata lead family have come to light. We present three cases of patients with Riata internal cardioverter defibrillator (ICD) leads with externalized conductors.

METHODS AND RESULTS

All patients had the same insulation defect, with externalized conductors, but differed in presentation and symptoms. These cases, which form 3 of 179 (1.68%) of our total Riata lead population, presented four or more years after implantation. This may be an indication that the problem with the Riata lead may well be greater than reported in the recent St Jude Medical device advisory letter.

CONCLUSION

The management of the Riata lead problem is discussed as, up until now, management of patients with an implanted Riata lead has been based on detecting electric abnormalities on regular ICD interrogation only.

ECG quantification of myocardial scar does not differ between primary and secondary prevention ICD recipients with ischemic heart disease

BACKGROUND

Myocardial scar is an anatomic substrate for potentially lethal arrhythmias. Recent study showed that higher QRS-estimated scar size using the Selvester QRS score was associated with increased arrhythmogenesis during electrophysiologic testing. Therefore, QRS scoring might play a potential role in risk stratification before implantable cardioverter defibrillator (ICD) implantation. In this study, we tested the hypothesis that QRS scores among ICD recipients for secondary prevention are higher than QRS scores in primary prevention patients.

METHODS AND RESULTS

From the hospital database, 100 consecutive patients with ischemic heart disease and prior ICD implantation were selected. Twelve-lead electrocardiograms (ECGs) had been obtained before implantation. ECGs were scored following the 32-points Selvester QRS scoring system and corrected for underlying conduction defects and/or hypertrophy. Ninety-three ECGs were suitable for scoring; seven ECGs were rejected because of noise, missing leads, excessive ventricular extrasystoles, or ventricular pacing. No statistically significant difference in QRS score was found between the primary [6.90 (standard deviation [SD] 3.94), n = 63] and secondary prevention group [6.17 (SD 4.50) (P = 0.260), n = 30]. Left ventricular ejection fraction (LVEF) was significantly higher in the secondary prevention group [31% (SD 13.5) vs 24% (SD 11.7) (P = 0.015)]. When patients with LVEF > or =35% were excluded, QRS scores were still comparable, namely 7.02 (SD 4.04) in the primary prevention group (n = 52) and 6.28 (SD 4.24) in the secondary (P = 0.510) (n = 18).

CONCLUSION

We found no significant difference in QRS score between the ischemic primary and secondary prevention groups. Therefore, a role of the Selvester QRS score as a risk stratifier remains unlikely.

Microvolt T-wave alternans during exercise and pacing are not comparable

AIMS

The absence of microvolt T-wave alternans (MTWA) identifies a group of patients who are at low risk for ventricular arrhythmia or sudden cardiac death. However, in exercised assessed MTWA, 20-40% of all test results are indeterminate. We hypothesised that MTWA during pacing would yield less indeterminate results.

METHODS AND RESULTS

Thirty patients with ischaemic cardiomyopathy and prior dual chamber implantable cardioverter defibrillator implantation were enrolled. All patients underwent sequential MTWA testing using an exercise (E), atrial-paced (A), and atrioventricular-paced (AV) protocol. The number of indeterminate tests was lower during pacing (A: 17%; AV: 3%) compared with exercise (37%) (E vs. A: P = 0.015, E vs. AV: P = <0.001). When positive and indeterminate test results were grouped as non-negative, the concordance rates between E and A, E and AV, and A and AV were 60% (kappa = 0.17), 57% (kappa = 0.058), and 70% (kappa = 0.348), respectively. If indeterminate results were excluded, agreements were 60% (kappa = 0.19), 50% (kappa = 0.129) and 67% (kappa = 0.33), respectively.

CONCLUSION

Indeterminate test results are less common during pacing. However, there is a low concordance rate between test results using different protocols. This necessitates further study to determine the predictive value of each method in high risk patients with ischaemic cardiomyopathy.

Challenging pacemaker implantation: persistent left superior vena cava with absent right superior vena cava

A persistent left superior vena cava (PLSVC) in combination with an absent right superior vena cava (RSVC) is a rare congenital cardiovascular abnormality which is usually found by chance during pacemaker (PM) implantation. In this case we describe a PM implantation using right cephalic approach through PLSVC and coronary sinus (CS), with lead fixation in right atrium and a posterolateral branch of the CS.

Acute success and short-term follow-up of catheter ablation of isthmus-dependent atrial flutter; a comparison of 8 mm tip radiofrequency and cryothermy catheters

Objectives

To compare the acute success and short-term follow-up of ablation of atrial flutter using 8 mm tip radiofrequency (RF) and cryocatheters.

Methods

Sixty-two patients with atrial flutter were randomized to RF or cryocatheter (cryo) ablation. Right atrial angiography was performed to assess the isthmus. End point was bidirectional isthmus block on multiple criteria. A pain score was used and the analgesics were recorded. Patients were followed for at least 3 months.

Results

The acute success rate for RF was 83% vs 69% for cryo (NS). Procedure times were similar (mean 144 ± 48 min for RF, vs 158 ± 49 min for cryo). More applications were given with RF than with cryo (26 ± 17 vs. 18 ± 10, p < 0.05). Fluoroscopy time was longer with RF (29 ± 15 vs. 19 ± 12 min, p < 0.02). Peak CK, CK-MB and CK-MB mass were higher, also after 24 h in the cryo group. Troponin T did not differ. Repeated transient block during application (usually with cryoablation) seemed to predict failure. Cryothermy required significantly less analgesia (p < 0.01), and no use of long sheaths (p < 0.005).

The isthmus tended to be longer in the failed procedures (p = 0.117). This was similar for both groups, as was the distribution of anatomic variations. Recurrences and complaints in the successful patients were similar for both groups, with a very low recurrence of atrial flutter after initial success.

Conclusions

In this randomized study there was no statistical difference but a trend to less favorable outcome with 8 mm tip cryocatheters compared to RF catheters for atrial flutter ablation. Cryoablation was associated with less discomfort, fewer applications, shorter fluoroscopy times and similar procedure times. The recurrence rate was very low. Cryotherapy can be considered for atrial flutter ablation under certain circumstances especially when it has been used previously in the same patient, such as in an AF ablation.

Outcome in patients with an ICD incorporating cardiac resynchronisation therapy: Differences between primary and secondary prophylaxis

BACKGROUND

The incidence of ventricular tachyarrhythmias in ICD patients with cardiac resynchronisation therapy (CRT-D) is not well studied.

AIM

To analyse event free survival in CRT-D patients with a primary or a secondary prophylactic ICD indication.

METHODS

Prospective, single centre. Eighty-six patients, 44% with a primary prophylactic indication. Actuarial event-free rates for mortality and arrhythmias were calculated.

RESULTS

Baseline clinical characteristics were not significantly different between primary and secondary prophylaxis. Primary prophylaxis patients were more likely to be in NYHA class III. Over 21 months, 724 ventricular events with therapy occurred in 36 patients (42%). The actuarial event-free rates, at 1 and 3 years, from appropriate ICD therapy were higher (P<0.001) for primary (79.0% and 67.8%) than for secondary prophylaxis (45.6% and 27.0%). Appropriate ICD therapy occurred more in NYHA class II compared to class III (P=0.016). Underlying disease (ischemic versus non-ischemic) and functional class did not play a role in multivariate analysis.

CONCLUSION

Important arrhythmic events in patients with heart failure, and CRT-D occur at a very high rate when the indication is secondary prophylaxis. Patients with primary prophylaxis have an annual event rate of 10%, even though they tend to have a worse heart failure class.

One-year follow-up in a prospective, randomized study comparing radiofrequency and cryoablation of arrhythmias in Koch's triangle: clinical symptoms and event recording

AIMS

To rely solely on clinical symptoms of recurrent palpitations to evaluate the success of interventional procedures can be misleading. This study was designed to assess the efficacy of event recording in evaluating long-term success in patients treated for atrioventricular nodal reentrant tachycardia (AVNRT) or right posteroseptally located accessory pathways (RPS) either by radiofrequency (RF) or by cryoablation (CA).

METHODS AND RESULTS

Sixty-three patients with AVNRT and eight with RPS were randomized. Patients were encouraged to activate an event recorder in the case of recurrent palpitations for the first 3 months. One year after the procedure, patients were asked specific arrhythmia related questions. Thirty-six patients underwent RF and 35 CA. Acute success was finally achieved in 34 (94%) patients in the RF and 33 (94%) in the CA groups. Assessment of long-term success demonstrated a similar proportion of palpitations in the RF and CA groups: 11 (31%) vs. 17 (49%). Only 12 patients activated the event recorder, four patients in RF, including one patient with chest pain, and eight in the CA group. Analysis of recordings revealed recurrent AVNRT or circus movement tachycardia in four patients (one RF and three CA), atrial fibrillation in one RF patient, and sinus tachycardia in six (one RF and five with CA). In addition, a complete 12 lead ECG of a recurrent arrhythmia was made in three RF and two CA patients (in-hospital or after the event recording). A total of seven patients underwent a second procedure (four RF and three CA). Without the event recorder, seven patients would have been misclassified as having recurrent arrhythmia.

CONCLUSION

Event recording enhances the sensitivity of detecting arrhythmia recurrences in evaluating therapy efficacy and should be considered in every interventional follow-up study. Analysis of recordings showed that CA is as effective as RF in the treatment of AVNRT and RPS at long-term follow-up.

Imaging of a coronary artery bypass graft during coronary sinus venography

Retrograde coronary sinus perfusion to maintain viability during cardiac surgery means that a connection via the capillary system to the coronary arteries, and potentially bypass grafts, may be possible. Coronary sinus (CS) venography prior to resynchronisation therapy in this patient with previous bypass grafting was associated with visualisation of these grafts.

Magnetic navigation in AV nodal re-entrant tachycardia study: early results of ablation with one- and three-magnet catheters

AIMS

Steering soft, flexible catheters using an external magnetic field could have advantages for heart catheterization, especially for therapy of tachyarrhythmias. Our aims were to assess the feasibility of magnetic navigation to Koch's triangle and reliable ablation of atrioventricular nodal re-entry tachycardia (AVNRT) with a magnetic catheter.

METHODS AND RESULTS

Consecutive patients with AVNRT were mapped and ablated with a magnetically enabled catheter (Helios I or II), with, respectively, one and three magnets at the tip. The catheter was remotely advanced with the Cardiodrive system and orientated with the Navigant control system. After initial positioning with the external magnets, adjustment was made in 5 degrees steps. Success rates, procedure, and fluoroscopy times were analysed, and compared with a local contemporary series of conventional AVNRT ablations. Magnetic navigation was feasible in all 20 patients. Targets were easily reached. Catheters remained stable in position during accelerated junctional rhythms. Ablation was successful in 18/20 procedures (90%). No significant complications occurred. Median patient fluoroscopy time was 12 min, median physician fluoroscopy time was 4 min. Fluoroscopy times tended to be shorter than that in the conventionally treated group. Procedure duration decreased significantly over time, median procedure time was similar to that in the conventional group.

CONCLUSION

AVNRT can be successfully mapped and ablated using magnetic navigation. A learning curve was evident, unrelated to catheter type, but to increasing operator experience. Physician radiation times were one-third of patient times. No complications occurred. Procedure time is comparable with that of conventional ablation.

Left Ventricular Lead Placement Within a Coronary Sinus Side Branch Using Remote Magnetic Navigation of a Guidewire: A Feasibility Study

BACKGROUND

A novel magnetic navigation system (MNS) allowing remote guidance of catheters and guidewires might assist in implantation of left ventricular (LV) pacing leads.

OBJECTIVE

To assess the feasibility of deploying a LV pacing lead into a coronary sinus (CS) side branch using a magnetically guided wire and of performing the procedure without a CS guiding sheath.

METHODS

Twenty-one patients were included in this study. Nine underwent CRT device implantation using a MNS to steer the guidewire (MNS group) while 12 patients were conventionally implanted (control group). In 6 patients in the MNS group, the procedure was performed using a CS guiding sheath. In 3 others, the decision was to perform the procedure without a CS sheath. In these patients the wire was advanced manually, while the external magnets oriented it toward the CS os. In the CS, "vector based" navigation was used to guide the wire to the desired side branch.

RESULTS

In all 9 patients in the MNS group, the target vessel could be successfully engaged by the magnetically guided wire. In 7, the LV lead was lodged in the target vessel. In 2 patients, the LV lead was repositioned in an anterolateral side branch due to instability or inability to engage the vessel with it. Mean total procedure time was 164 +/- 58 minutes (without sheath 229 +/- 52 vs with sheath 132 +/- 26 minutes; P = 0.007). Mean fluoroscopy time was 28 +/- 9 minutes. For control patients, the procedure and fluoroscopy time were similar (144 +/- 41 minutes and 26 +/- 12 minutes, respectively). No major complications occurred.

CONCLUSION

LV lead implantation can be performed using a remote magnetically steered guidewire. Though the lead could be implanted without a CS guiding sheath, longer procedure times were required.

Intracardiac echocardiography during interventional procedures

BACKGROUND

As non-surgical percutaneous interventions are increasingly considered for many cardiac conditions, high quality near field continuous imaging is warranted, in order to optimize the results, and to prevent and detect complications. Transesophageal echocardiography is the standard imaging technique, however general anesthesia and endotracheal intubation is required during prolonged monitoring of percutaneous interventions. Intracardiac echocardiography is a novel emerging tool that allows a view within the cardiac chambers and the large vessels and can be employed by the interventional cardiologist.

METHOD

In our department, a phased array, multi-frequency, four-way steerable catheter (AcuNaV - Siemens) was used for anatomic and haemodynamic cardiac assessment and for guidance and monitoring during non-coronary percutaneous interventions. In total 135 patients underwent intracardiac echocardiographic investigation, 4 during diagnostic heart catheterization, 6 during percutaneous coronary intervention with the use of a new left ventricular assist device, the Impella Recover LP 2.5 system, 26 during percutaneous transluminal septal myocardial ablation (10 patients were reevaluated with intracardiac echocardiography at 6 months), 50 during interatrial communication closure, 4 during percutaneous left atrial appendage transcatheter occlusion, 7 during percutaneous balloon valvuloplasty, 1 during percutaneous aortic valve replacement and 27 during pulmonary vein ablation. All patients tolerated the procedure very well with no catheter related complications. However, there were two complications, which were due to the guidewire and the sheath, an inferior vena cava dissection and a femoral vein dissection, respectively.

CONCLUSION

Phased array intracardiac imaging is a safe technology, which facilitates non-surgical interventions by providing high quality images. It eliminates the need for general anesthesia and thus increases the patient comfort.

Contrast echocardiography for perfusion in right ventricular cardiomyopathy

Right ventricular (RV) cardiomyopathy is a familiar myocardial disease of RV characterized by extensive fatty replacement of the myocardium. Conventional echocardiography is able to show abnormalities in myocardial contractility, but fat on the images appears to be similar to the surrounding tissue or fluid. The present case suggests the clinical role of contrast echocardiography showing perfusion abnormalities in patients with RV cardiomyopathy in the region of the fat depositions.

Targets and endpoints in ablation therapy for atrial fibrillation in the light of pathophysiological mechanisms

Atrial fibrillation (AF), an important public health problem is a complex and multifactorial arrhythmia. Non-pharmacological treatment for symptomatic patients is of increasing importance. The different catheter ablation techniques in AF treatment developed during recent years, all based on different pathophysiological insights, are discussed. The non-standardized use of different follow-up methods after ablation make interpretation and comparison of results difficult.

Pulmonary vein antrum isolation guided by phased-array intracardiac echocardiography: A third way to do PV ablation

BACKGROUND

Pulmonary vein isolation (PVI) has emerged as an important strategy in the treatment of patients with atrial fibrillation (AF). The two most frequently used techniques are segmental PVI and left atrial circumferential ablation.

AIM

To describe and discuss pulmonary vein antrum isolation guided by phased-array intracardiac echocardiography (ICE) as an alternative approach, and to present initial results.

METHODS

Patients with symptomatic AF were included. The antra (the larger circumferential area around the PVs) were isolated guided by ICE. ICE was also used to titrate the ablation energy.

RESULTS

38 patients (3 with persistent AF) were included. Of the 35 patients with paroxysmal AF, 24 are without recurrences, and in six the incidence of paroxysms was significantly reduced after one procedure and a mean follow-up of 201 days. No major complications occurred.

CONCLUSION

Pulmonary vein antrum isolation guided by ICE is a promising technique in AF ablation and has the potential to avoid severe complications.

Anticoagulation in atrial fibrillation and flutter

Atrial fibrillation and atrial flutter are important risk factors for stroke. Based on a literature search, pathogenesis of thromboembolism, risk assessment in patients, efficacy of anticoagulation therapy and its alternatives are discussed. Special emphasis is put on issues like paroxysmal atrial fibrillation, atrial flutter and anticoagulation surrounding catheter ablation and cardioversion. A strategy for anticoagulation around the time of pulmonary vein ablation is suggested.

Combined transesophageal echocardiography and transesophageal cardioversion probe: technical aspects

A probe assembly for simultaneous transesophageal echocardiography and transesophageal cardioversion has been developed. This probe allows cardioversion with the delivery of much lower energy than the standard external approach. Details of the probe construction and its use are described, as is the prospect for future practice. The use of a combined probe may be the technique of choice for patients who require both cardioversion and transesophageal echocardiography.

Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1+/-2.4 preprocedural versus 18.6+/-2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2+/-0.2 versus 1.2+/-0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1+/-2.5 mm versus 16.5+/-2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up.

CRAVT: a prospective, randomized study comparing transvenous cryothermal and radiofrequency ablation in atrioventricular nodal re-entrant tachycardia

BACKGROUND

Transvenous catheter ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) with radiofrequency (RF) is effective and safe, but carries a 1-3% incidence of early and potentially late heart block. Cryothermy can create transient effects, and identify potentially successful ablation sites and decrease the risk for permanent heart block.

METHODS

In this prospective, randomized trial 102 patients with recurrent narrow QRS-complex tachycardia suggestive of AVNRT were randomized to either RF or cryoablation before a diagnostic study.

RESULTS

In 63 patients with AVNRT, 33 were randomized to RF and 30 to cryoablation. Procedural success was achieved, respectively, in 30 (91%) patients in the RF and 28 (93%) in the cryoablation group. The median number of cryothermal applications was significantly lower than the number of RF applications (2 versus 7, p<0.005). No accelerated junctional rhythm was seen with cryothermy, while it was present in 31/33 RF patients. Both fluoroscopy and procedural times were comparable. The radiological position of the successful site in relation to anatomical landmarks was slightly different (p<0.05). No cryothermy related complications were observed, and no permanent AV conduction disturbances occurred. During a mean follow up of 13+/-7 months long-term clinical success was seen in one additional patient in each group. In the same period, 3 patients in both groups experienced recurrent AVNRT.

CONCLUSION

Cryoablation is as effective and safe as RF for AVNRT. Significantly fewer applications are necessary, with comparable procedure times. This makes cryothermy useful for the treatment of tachyarrhythmias near the compact AV node.

Usefulness of transesophageal echocardiography using a combined probe when converting atrial fibrillation to sinus rhythm

We studied the feasibility and efficacy of transesophageal echocardiography (TEE) combined with transesophageal cardioversion (TEC). Secondary aims were to study left atrial flow velocities before and 1 and 5 minutes after TEC, biochemical markers of myocardial damage, and patient tolerability. TEC after a short period of anticoagulation and exclusion of a clot with TEE was safe. TEC was well tolerated and efficacious. The use of a combined probe for TEE and TEC therefore can save time and be more effective. A custom-made probe for combined TEE plus TEC was used. TEC was performed with a step-up protocol (20 J to between 30 and 50 J) and with biphasic shocks. Presence of spontaneous echo contrast was scored. Cumulative energy needed to achieve sinus rhythm was calculated. Discomfort was scored on a scale of 0 to 10. Twenty-six patients underwent combined TEE/TEC. Sinus rhythm was achieved in 24 of 26 patients (92%) with a mean cumulative energy of 42.3 J. Sixteen of 26 patients were cardioverted with a 20-J shock, and 6 of these patients had early recurrence of atrial fibrillation. All biochemical markers were unaffected, and TEE/TEC was well tolerated. Left atrial appendage velocity decreased significantly after TEC. Thus, the use of a TEE/TEC probe offers effective cardioversion with low energy levels, is well tolerated, and hemodynamics during and immediately after cardioversion can be monitored. Early cardioversion after exclusion of a clot with this combined probe is time saving and cost effective.

Twiddler's Syndrome Detected by Home Monitoring Device

Lead fracture due to twiddler's syndrome, was detected in a 68-year-old patient 1 month after implantation of an ICD by means of the incorporated home monitoring system. The patient was admitted and the lead replaced. This case illustrates the clinical benefit of the home monitoring system.

Visualization of a coronary sinus valve using intracardiac echocardiography

Cannulation of the coronary sinus (CS) is sometimes difficult due to the presence of anatomical anomalies. Fluoroscopy is of limited value in visualizing these variations. This case is the first to demonstrate how intracardiac echocardiography (ICE) allows visualization of a valve, which is one of the causes of problematic cannulation of the CS. Based on information obtained by ICE an appropriate catheter could be selected.

First Dutch experience with percutaneous left atrial appendage transcatheter occlusion

BACKGROUND

Patients with atrial fibrillation (AF) have an increased risk of thromboembolic stroke, dependent on clinical variables. Oral anticoagulation significantly decreases the risk of stroke or embolism, but sometimes this is difficult to manage and may be contraindicated. Approximately 90% of atrial thrombi in nonrheumatic AF are found in the left atrial appendage (LAA). A new device has been developed which allows percutaneous LAA occlusion (PLAATO) and might be an alternative to oral anticoagulation. Feasibility in dogs and humans was described previously.

METHODS AND RESULTS

As part of an international multicentre trial, three patients received a percutaneous transcatheter LAA occlusion device. Implantations were performed without general anaesthesia, guided by intracardiac and transoesophageal echocardiography and without major complications. The implantations were well tolerated by the patients, who entered a long-term follow-up to be compared with a historical control group.

CONCLUSION

Transseptal percutaneous LAA occlusion is feasible. Its role as an alternative to oral anticoagulation, however, needs to be further defined.

Electrical isolation of pulmonary veins using cryothermal energy: study design and initial results

In the September 2003 issue of the Netherlands Heart Journal, the wrong figures where inserted in this article. The article is reprinted here with the correct figures.

BACKGROUND

Atrial fibrillation (AF) is the most frequently encountered arrhythmia. Radiofrequency pulmonary vein (PV) ablation is promising for symptomatic paroxysmal AF, but is associated with a significant risk of PV stenosis.

OBJECTIVES

To assess the efficacy of cryothermal PV ablation and the incidence of PV stenosis.

METHODS

Highly symptomatic patients with paroxysmal or persistent AF were eligible for cryothermal ablation. Multislice spiral CT scans were performed before, and three months after ablation. AF burden was assessed using transtelephonic ECG recording and by telephone enquiry.

RESULTS

An attempt was made to isolate 27 PVs in 15 patients. In total, 20 PVs could be isolated (74% acute success). No significant difference in PV diameter was seen before and after ablation. Five out of 12 patients with paroxysmal AF were completely without AF after one ablation procedure. An additional two patients reported a significant reduction in symptoms. In the three patients with persistent AF no improvement was reported.

CONCLUSION

Cryothermal PV ablation was effective in isolation of the targeted PVs. It appears to be safe, as no PV stenosis was seen in this study three months after the ablation. Taking into account a learning curve, we consider the clinical results to be very promising.

Electrical isolation of pulmonary veins using cryothermal energy: study design and initial results

BACKGROUND

Atrial fibrillation (AF) is the most frequently encountered arrhythmia. Radiofrequency pulmonary vein (PV) ablation is promising for symptomatic paroxysmal AF, but is associated with a significant risk of PV stenosis.

OBJECTIVES

To assess the efficacy of cryothermal PV ablation and the incidence of PV stenosis.

METHODS

Highly symptomatic patients with paroxysmal or persistent AF were eligible for cryothermal ablation. Multislice spiral CT scans were performed before, and three months after ablation. AF burden was assessed using transtelephonic ECG recording and by telephonic enquiry.

RESULTS

An attempt was made to isolate 27 PVs in 15 patients. In total, 20 PVs could be isolated (74% acute success). No significant difference in PV diameter was seen before and after ablation. Five out of 12 patients with paroxysmal AF were completely without AF after one ablation procedure. An additional two patients reported a significant reduction in symptoms. In the three patients with persistent AF no improvement was reported.

CONCLUSION

Cryothermal PV ablation was effective in isolation of the targeted PVs. It appears to be safe, as no PV stenosis was seen in this study three months after the ablation. Taking into account a learning curve, we consider the clinical results to be very promising.