Hospital utilisation and the costs associated with complications of ICD implantation in a contemporary primary prevention cohort

Introduction

Implantation of an implantable cardioverter defibrillator (ICD) is standard care for primary prevention of sudden cardiac death. However, ICD-related complications are increasing as the population of ICD recipients grows.

Methods

ICD-related complications in a national DO-IT Registry cohort of 1442 primary prevention ICD patients were assessed in terms of additional use of hospital care resources and costs.

Results

During a median follow-up of 28.7 months (IQR 25.2–33.7) one or more complications occurred in 13.5% of patients. A complication resulted in a surgical intervention in 53% of cases and required on average 3.65 additional hospital days. The additional hospital costs were €6,876 per complication or €8,110 per patient, to which clinical re-interventions and additional hospital days contributed most. Per category of complications, infections required most hospital utilisation and were most expensive at an average of €22,892. The mean costs were €5,800 for lead-related complications, €2,291 for pocket-related complications and €5,619 for complications due to other causes. We estimate that the total yearly incidence-based costs in the Netherlands for hospital management of ICD-related complications following ICD implantation for primary prevention are €2.7 million.

Conclusion

Complications following ICD implantation are related to a substantial additional need for hospital resources. When performing cost-effectiveness analyses of ICD implantation, including the costs associated with complications, one should be aware that real-world complication rates may deviate from trial data. Considering the economic implications, strategies to reduce the incidence of complications are encouraged.

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

Implantable cardioverter defibrillators at the end of life: future perspectives on clinical practice

The implantable cardioverter defibrillator (ICD) is effective in terminating life-threatening arrhythmias. However, in the last phase of life, ICD shocks may no longer be appropriate. Guidelines recommend timely discussion with the patient regarding deactivation of the shock function of the ICD. However, research shows that such conversations are scarce, and some patients experience avoidable and distressful shocks in the final days of life. Barriers such as physicians’ lack of time, difficulties in finding the right time to discuss ICD deactivation, patients’ reluctance to discuss the topic, and the fragmentation of care, which obscures responsibilities, prevent healthcare professionals from discussing this topic with the patient. In this point-of-view article, we argue that healthcare professionals who are involved in the care for ICD patients should be better educated on how to communicate with patients about ICD deactivation and the end of life. Optimal communication is needed to reduce the number of patients experiencing inappropriate and painful shocks in the terminal stage of their lives.

Prevalence of anxiety and risk associated with ventricular arrhythmia in patients with an implantable cardioverter defibrillator

BACKGROUND

Anxiety has been associated with adverse clinical outcomes in patients who have received an implantable cardioverter defibrillator (ICD). However, results are inconclusive likely due to different measures being used to assess anxiety. Hence, the current study aims to examine the prevalence and the association between anxiety, ventricular tachyarrhythmia's (VTa's) and all-cause mortality, respectively.

METHODS

Patients who received an ICD for the first time were recruited from 6 Dutch referral hospitals as part of the WEBCARE trial. Patients filled in validated questionnaires (GAD-7, STAI-S, HADS-A, ANX4, ICDC, FSAS) to assess their baseline anxiety symptomatology. Logistic regression analysis and Cox Regression analysis were performed to examine the association between anxiety with 1) VTa's and 2) mortality, respectively.

RESULTS

A total of 214 Patients were included in the analysis with mean age 58.9 and 82.7% being male. The prevalence rates of anxiety varied depending on which questionnaire was used 12.4% (GAD-7), 17.5% (HADS-A), and 28.1% (STAI-S). (Cox) Regression analysis revealed that none of the anxiety measures was associated with VTa's or all-cause mortality in the current sample. Stratifying the sample by gender, the analysis showed that GAD-7, STAI-S, and ANX4 scores were associated with increased risk of VTa's but only in male patients.

CONCLUSIONS

Prevalence rates of anxiety varied depending on the measurement tool used. No significant association between anxiety and VTa's and all-cause mortality was observed in the total sample. GAD-7, STAI-S, and ANX4 were associated with increased risk for VTa's but only in male patients.

Personality traits, ventricular tachyarrhythmias, and mortality in patients with an implantable cardioverter defibrillator: 6 years follow-up of the WEBCARE cohort

OBJECTIVE

Risk stratification within the ICD population warrants the examining of the role of protective- and risk factors. Current study examines the association between Type D personality, pessimism, and optimism and risk of ventricular tachyarrhythmias (VTa's) and mortality in patients with a first-time ICD 6 years post implantation.

METHODS

A total of 221 first-implant ICD patients completed questionnaires on optimism and pessimism (Life Orientation Test) and Type D personality (Type D scale DS14) 10 to 14 days after implantation. VTa's and all-cause mortality 6 years post implant comprised the study endpoints.

RESULTS

Ninety (40.7%) patients had experienced VTa's and 37 (16.7%) patients died, 12 (5.4%) due to a cardiac cause. Adjusted logistic regression analysis showed that pessimism was significantly associated with increased risk of VTa's (OR = 1.09; 95% CI = 1.00-1.19; p = .05). Type D personality (OR = 1.05; 95% CI = 0.47-2.32; p = .91) and optimism (OR = 1.00; 95% CI = 0.90-1.12; p = .98) were not associated with VTa's. None of the personality types were associated with mortality.

CONCLUSION

Pessimism was associated with VTa's but not with mortality. No significant association with either of the endpoints was observed for Type D personality and optimism. Future research should focus on the coexistent psychosocial factors that possibly lead to adverse cardiac prognosis in this patient population.

P2881Eligibility for a subcutaneous defibrillator based on standard 12-lead electrocardiogram

Background

Currently, the eligibility for a subcutaneous implantable defibrillator (S-ICD) system relies on a pre-implant vector screening based on the automated screening tool (AST).

Objective

To determine 12-lead ECG characteristics associated with eligibility for an S-ICD in a heterogeneous population at risk for sudden cardiac death (SCD). The goal is to determine patient eligibility for S-ICD using the standard 12-lead ECG, thereby avoiding additional AST screening.

Methods

We prospectively evaluated the eligibility for an S-ICD in 254 consecutive patients at risk for SCD. We identified 12-lead ECG parameters which were independently associated with AST passing (≥1 vector) using multivariable logistical regression analysis in our derivation cohort. The final model was tested in a separate validation cohort.

Results

The overall passing rate was 92% in our derivation cohort. Independent 12-lead ECG characteristics associated with AST passing were QRS≤130 ms, absence of QRS/T discordance in lead II and R/T-ratio ≥3.5 in lead II (Table). Eighty-three of 254 patients (33%) fulfilled these three criteria and had a passing rate of 100%. Of the validation cohort, 37 of 60 patients (62%) fulfilled all three criteria and also had a passing rate of 100%. The interobserver agreement for applying the ECG model was 90% (Cohen's Kappa=0.80).

Table 1 Variables Univariable Multivariable OR (95% CI) P-value OR (95% CI) P-value QRS ≤130 ms 9.65 (3.66–25.43) <0.01 8.09 (2.88–22.77) <0.01 QTc ≤450 ms 3.33 (1.18–9.54) 0.02 Absence of T-wave inversion in lead I 2.74 (1.03–7.25) 0.04 Absence of T-wave inversion in lead II 3.65 (1.29–10.33) 0.02 Absence of QRS/T-wave discordance in lead II 5.05 (1.98–12.92) <0.01 4.19 (1.49–11.74) <0.01 Absence of QRS/T-wave discordance in lead aVF 3.95 (1.53–10.19) <0.01 R/T-ratio ≥3.5 in lead II 3.58 (1.27–10.01) 0.02 4.21 (1.27–13.95) 0.02 R/T-ratio ≥3.5 in lead aVF 3.16 (1.18–8.42) 0.02 OR = odds ratio; CI = confidence interval.

Figure 1

Conclusion

Using the standard 12-lead ECG, we developed a simple screening model with a high specificity for S-ICD eligibility. Our results suggest that patients who fulfill the three ECG criteria do not need additional AST-screening. Therefore, we developed a simple flowchart to determine eligibility for an S-ICD that can be easily implemented in daily clinical practice (Figure).

P5428QRS narrowing more than 15 ms after CRT implantation is strongly associated with the long-term survival

Background

Cardiac resynchronization therapy (CRT) is used in selected heart failure patients with electrical cardiac dyssynchrony with a prolonged QRS duration and a left ventricle ejection fraction (LVEF) ≤35%. QRS duration post CRT implantation can probably predict responders and survivors. The aim of our study is to investigate the effect of QRS change on long-term survival post CRT implantation.

Methods

We performed a retrospective cohort study in patients receiving a CRT device in our tertiary referral center between January 2009 and January 2018. Clinical and electrocardiographic (ECG) data were collected at baseline, one week after CRT implantation, six months, and yearly during follow-up. The primary endpoint was death, left ventricle assisting device implantation, or heart transplantation. At the end, the cohort was dichotomized to the cut-off value of ≥15ms according current literature.

Results

The study population consisted of 219 patients of whom 145 (66%) patients were survivors and 74 (34%) non-survivors. Non-survivors were significantly older (63 vs. 68 years, p=0.001), male gender (67% vs. 82%, p=0.015), had more often diabetes mellitus (20% vs. 39%, p=0.002), chronic obstructive pulmonary disease (12% vs. 28%, p=0.003), an ischemic etiology of heart failure (42% vs. 61%, p=0.009) with previous myocardial infarction (29% vs 53%, p=0.001), previous revascularization (32% vs. 49%, p=0.019), atrial fibrillation (21% vs. 39%, p=0.004), worser NYHA class (p=0.008), and amiodarone use (10% vs. 22%, p=0.024). Blood urea nitrogen (BUN) (8.1 mmol/L vs. 10.4 mmol/L, p<0.001) and creatinine levels (96 μmol/L vs. 114 μmol/L, p=0.001) were also higher in the non-survivors group. Median QRS duration (168 ms IQR [154 to 182]) at baseline was comparable between survivors and non-survivors (170 ms vs. 166 ms, p=0.17). However, median QRS change one week after CRT implantation was significantly better in the survivors (−19 ms IQR [−30 to −2] vs. −6 ms IQR [−24 to +12], p=0.004). The QRS change at the last FU (median 5.1 years IQR [2.9 to 7.8] was consistently higher in the survivor group (−16 ms IQR [−29 to 0] vs. +1 ms IQR [−27 to +20], p=0.004). Dichotomized to ΔQRS narrowing of ≥15 ms after CRT implantation showed significantly better long-term survival (figure).

Kaplan-Meier curve

Conclusion

QRS narrowing cut-off of ≥15 ms post CRT implantation is strongly associated with the long term survival in chronic heart failure patients with reduced LVEF.

P5421Prevalence of electromagnetic interference from left ventricular assist devices in patients with implantable cardioverter defibrillator/pacemakers

Background

Many patients eligible for left ventricular assist device (LVAD) therapy already have an implantable cardioverter defibrillator (ICD) and/or pacemaker (PM). However, electromagnetic interference (EMI) between the LVAD and ICD/PM devices could be cumbersome.

Purpose

The aim of this study was to investigate the prevalence of EMI between different types of ICD/PM in patients implanted with an LVAD.

Methods

Data was obtained through a retrospective electronic patient database analysis of all LVAD patients (including HeartMate II (HMII) and HeartMate 3 (HM3)), from our tertiary referral center, from December 2006 to February 2019. Device switches have also been taken into account due to elective replacement. Electromagnetic interference was defined as ICD/PM telemetry interference (i.e. the inability to interrogate ICD/PM)

Results

In total, 109 patients received an LVAD (mean age 52±12, 83% male), Of these, 86 (79%) patients had an ICD/PM at LVAD implantation. One patient with ICD/PM was excluded from further analysis because of missing follow-up data. Among the 85 patients (45 HM II and 40 HM3), 11 (13%) experienced EMI; 5 (11%) with a HM II and 6 (15%) with a HM3 (p=0.59). The implanted ICD/PM devices were from Medtronic (n=25), Abbott (n=23), Biotronik (n=18), Boston Scientific (n=18), and Microport (n=1). EMI with the HM II was present in St Jude/Abbott devices (type 1 Atlas, 1 Unify, 1 Fortify, and 2 Promote). In HM 3 LVAD patients, EMI was observed in Biotronik devices (1 Lumax, 1 Ilivia, 1 Ilesto, and 2 Iperia) and Medtronic (Claria).

Conclusion

In our cohort of HM II and HM 3 LVAD patients, at least one in seven patients experienced EMI from either the HM II or HM3 LVAD with the ICD/PM. Electromagnetic interference from HM II LVADs was mainly present in patients with St Jude/Abbott ICD/PM devices However, in the HM3 patients, EMI was mainly present in patients with Biotronik devices, which is not yet widely known!

Dutch outcome in implantable cardioverter-defibrillator therapy (DO-IT): registry design and baseline characteristics of a prospective observational cohort study to predict appropriate indication for implantable cardioverter-defibrillator

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are widely used for the prevention of sudden cardiac death. At present, both clinical benefit and cost-effectiveness of ICD therapy in primary prevention patients are topics of discussion, as only a minority of these patients will eventually receive appropriate ICD therapy.

METHODS/DESIGN

The DO-IT Registry is a nationwide prospective cohort with a target enrolment of 1,500 primary prevention ICD patients with reduced left ventricular function in a setting of structural heart disease. The primary outcome measures are death and appropriate ICD therapy for ventricular tachyarrhythmias. Secondary outcome measures are inappropriate ICD therapy, death of any cause, hospitalisation for ICD related complications and for cardiovascular reasons. As of December 2016, data on demographic, clinical, and ICD characteristics of 1,468 patients have been collected. Follow-up will continue up to 24 months after inclusion of the last patient. During follow-up, clinical and ICD data are collected based on the normal follow-up of these patients, assuming ICD interrogations take place every six months and clinical follow-up is once a year. At baseline, the mean age was 66 (standard deviation [SD] 10) years and 27% were women.

CONCLUSION

The DO-IT Registry represents a real-world nationwide cohort of patients receiving ICDs for primary prevention of sudden cardiac death with reduced left ventricular function in a setting of structural heart disease. The registry investigates the efficacy of the current practice and aims to develop prediction rules to identify subgroups who will not (sufficiently) benefit from ICD implantation and to provide results regarding costs and budget impact of targeted supply of primary preventions ICDs.

ICDs at higher age and clinical risk factors

BACKGROUND

The implantable cardioverter defibrillator (ICD) is effective in preventing sudden cardiac death. However, in elderly patients (aged 75 years or older) the role of ICDs is still not well-defined and controversial.

METHODS

We retrospectively analysed all clinical and survival data of all ICD patients who were ≥75 years at the date of implantation in the Erasmus MC, Rotterdam, the Netherlands and the University Hospital, Basel, Switzerland. Kaplan-Meier survival analysis was performed, and mortality predictors were identified. Mortality of the cohort was compared with a random sample of patients aged 60-70 years originating from the same database and to an age- and sex-matched cohort of Dutch persons.

RESULTS

The study cohort consisted of 179 patients aged 75 years or older who were implanted between February 1999 and July 2008. The median follow-up time was 2.0 (IQR 2.8) years. Survival rates after 1, 2 and 3 years were 87, 82, 75 %, respectively. Survival was similar for primary and secondary prevention. Mortality in this study population could be predicted by combining four clinical risk factors: QRS duration >120 ms, NYHA class > II, renal failure and atrial fibrillation (AF). Survival was worse compared with the group of ICD patients aged 60-70 years and to the age- and sex-matched group of elderly persons. However, survival was not significantly worse when comparing elderly ICD patients without additional risk factors to the general population.

CONCLUSIONS

Elderly patients still have an acceptable survival probability independent of prevention indication, certainly if there are no additional clinical risk factors. The presence or absence of additional clinical risk factors should be taken into account when making the decision for implantation, since they strongly correlate with survival.

Clinical outcome of ablation for long-standing persistent atrial fibrillation with or without defragmentation

OBJECTIVE

To assess the outcome and associated risks of atrial defragmentation for the treatment of long-standing persistent atrial fibrillation (LSP-AF).

METHODS

Thirty-seven consecutive patients (60.4 ± 7.3 years; 28 male) suffering from LSP-AF who underwent pulmonary vein isolation (PVI) and linear ablation were compared. All patients were treated with the Stereotaxis magnetic navigation system (MNS). Two groups were distinguished: patients with (n = 20) and without (n = 17) defragmentation. The primary endpoint of the study was freedom of AF after 12 months. Secondary endpoints were AF termination, procedure time, fluoroscopy time and procedural complications. Complications were divided into two groups: major (infarction, stroke, major bleeding and tamponade) and minor (fever, pericarditis and inguinal haematoma).

RESULTS

No difference was seen in freedom of AF between the defragmentation and the non-defragmentation group (56.2 % vs. 40.0 %, P = 0.344). Procedure times in the defragmentation group were longer; no differences in fluoroscopy times were observed. No major complications occurred. A higher number of minor complications occurred in the defragmentation group (45.0 % vs. 5.9 %, P = 0.009). Mean hospital stay was comparable (4.7 ± 2.2 vs. 3.4 ± 0.8 days, P = 0.06).

CONCLUSION

Our study suggests that complete defragmentation using MNS is associated with a higher number of minor complications and longer procedure times and thus compromises efficiency without improving efficacy.

Adenosine testing after cryoballoon pulmonary vein isolation improves long-term clinical outcome

BACKGROUND

Adenosine infusion after pulmonary vein isolation (PVI) with radiofrequency energy reveals dormant muscular sleeves and predicts atrial fibrillation (AF) recurrence. The aim of our study was to determine whether adenosine could reveal dormant PV sleeves after cryoballoon isolation and study its effect on long-term recurrence of AF.

METHODS

Patients with paroxysmal AF underwent cryoballoon PVI. After PVI, adenosine 25 mg was infused to test for dormant muscular sleeves in each vein. If reconnection under adenosine was shown, further cryoballoon ablation was performed until no more reconnection occurred. Follow-up was performed with ECG, 24-h Holter recording, and a symptom questionnaire at three monthly intervals. Transtelephonic Holter monitoring was performed for 1 month before and 3 months after PVI. Patients who underwent cryoballoon PVI without adenosine administration were used as controls for comparison.

RESULTS

In the study group (n = 34, 24 males), adenosine revealed dormant sleeves in 9/132 (8 %) veins, and 7/34 (21 %) patients. All but one vein was further treated until the dormant sleeves were isolated. During a mean follow-up of 520 ± 147 days, 23/34 (68 %) patients were free of AF without antiarrhythmic drugs (AADs). In the control group (n = 65, 46 males), 29/65 (46 %) were free of AF without AADs. There were significantly less AF recurrences in the study group (p = 0.04).

CONCLUSIONS

Adenosine administration after cryoballoon PVI reveals dormant muscular sleeves in 21 % of patients. Clinical follow-up shows that adenosine testing is effective in reducing AF recurrence after cryoballoon ablation.

Remote monitoring and follow-up of cardiovascular implantable electronic devices in the Netherlands : An expert consensus report of the Netherlands Society of Cardiology

Remote monitoring of cardiac implanted electronic devices (CIED: pacemaker, cardiac resynchronisation therapy device and implantable cardioverter defibrillator) has been developed for technical control and follow-up using transtelephonic data transmission. In addition, automatic or patient-triggered alerts are sent to the cardiologist or allied professional who can respond if necessary with various interventions. The advantage of remote monitoring appears obvious in impending CIED failures and suspected symptoms but is less likely in routine follow-up of CIED. For this follow-up the indications, quality of care, cost-effectiveneness and patient satisfaction have to be determined before remote CIED monitoring can be applied in daily practice. Nevertheless remote CIED monitoring is expanding rapidly in the Netherlands without professional agreements about methodology, responsibilities of all the parties involved and that of the device patient, and reimbursement. The purpose of this consensus document on remote CIED monitoring and follow-up is to lay the base for a nationwide, uniform implementation in the Netherlands. This report describes the technical communication, current indications, benefits and limitations of remote CIED monitoring and follow-up, the role of the patient and device manufacturer, and costs and reimbursement. The view of cardiology experts and of other disciplines in conjunction with literature was incorporated in a preliminary series of recommendations. In addition, an overview of the questions related to remote CIED monitoring that need to be answered is given. This consensus document can be used for future guidelines for the Dutch profession.

Use of remote monitoring in the management of system-related complications in implantable defibrillator patients

Remote monitoring of implantable defibrillators (ICDs) is designed to minimise regular follow-up visits and to facilitate early detection of adverse events. With the increased rate of ICD implantations in today's clinical setting and multiple device advisories, which pose management challenges, this approach becomes very attractive. The aim of this article is to present the role of remote monitoring in the detection of system-related complications, its potential benefits and its barriers in the outpatient management of ICD patients.

The role of remote monitoring in the reduction of inappropriate implantable cardioverter defibrillator therapies

Implantable cardioverter defibrillators (ICDs) with the integrated Home Monitoring feature use dedicated mobile phone and internet links to provide the physicians and technicians in the ICD clinic with the essential device- and arrhythmia-related data stored in the ICD diagnostic memory. Various counters, graphs and intracardiac electrograms are automatically transmitted via Home Monitoring each day to allow prompt, remote presentation of arrhythmias or detection of technical problems. One of the most inconvenient side-effects of the ICD therapy is inappropriate intervention of the device. Home Monitoring data can help the physician to identify and subsequently reduce the incidence of inappropriate ICD therapy.

Ten year follow-up after radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia in the early days forever cured, or a source for new arrhythmias?

BACKGROUND

Radiofrequency (RF) catheter ablation is highly effective with a low complication rate. However, lesions created by RF energy are irreversible, inhomogeneous, and therefore potentially proarrhythmic.

OBJECTIVES

The aim of this study was to examine the magnitude and importance of long-term proarrhythmic effects of RF energy.

METHODS AND RESULTS

Between 1991 and 1995, 120 patients underwent RF ablation for atrioventricular nodal reentrant tachycardia (AVNRT). Patient data were collected by contacting patients and/or filling out a questionnaire, and medical files were screened for recurrent, documented arrhythmias, pharmacological treatment, and repeated EP study. Referring cardiologists were asked about recurrences of tachyarrhythmias. Fourteen patients (11%) were lost to follow-up. During a mean follow-up of 10 years, six patients died. Recurrences of AVNRT were not any more observed after 3 years after ablation. A total of 29 patients (24%) suffered from new arrhythmias, 6 from type 1 atrial flutter, 6 from atrial tachycardia, 9 from atrial fibrillation, and finally 16 from symptomatic premature atrial contractions (PACs), needing medical treatment or a combination of these arrhythmias. Nine patients underwent pacemaker implantation, 4 after developing procedural atrioventricular (AV) conduction disturbances, 2 after His ablation for permanent atrial fibrillation, 1 patient for sick sinus syndrome, and another 2 patients after developing late AV block, respectively, 7 and 9 years after ablation.

CONCLUSION

During long-term follow-up after RF ablation for AVNRT, no AVNRT recurrences were observed, but 29 patients (24%) suffered from new arrhythmias or late AV block. This potential proarrhythmic effect of RF energy promotes the application of alternative energy sources for ablative therapies for cardiac arrhythmias.

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.

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.

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.

Home monitoring in ICD therapy: future perspectives

The expanding indications for ICD therapy and the complexity of current devices will have impact on follow-up policy. The application of ICD therapy requires elaborate attention to technical aspects, arrhythmias, and the clinical course of the underlying disease. Currently, the quality of medical supervision is dependent on scheduled regular follow-up visits. A disadvantage of long intervals can be a delay in the physician's or patient's awareness of changes in the clinical status. Some patients will need more intensive follow-up while others will have the device as a stand-by and only need technical follow-up. A possibility to address this situation, is the transmission of data, already stored in the implanted device. This will guarantee continuous patient surveillance and could possibly help to avoid unnecessary follow-up visits.

Hybrid pharmacological and ablative therapy for the management of symptomatic atrial fibrillation

BACKGROUND

Hybrid therapy for atrial fibrillation class 1C and class III antiarrhythmic drugs (AAD) can convert atrial fibrillation (AF) into an isthmus-dependent atrial flutter (AFL) in more than 10% of patients. Hybrid pharmacological and ablative therapy offers a safe and effective approach to achieving and maintaining sinus rhythm. We evaluated the efficacy of this hybrid approach in the management of paroxysmal or persistent AF.

METHODS

Eighteen patients with symptomatic AF treated with AAD and typical anticlockwise/clockwise AFL underwent radiofrequency (RF) ablation of AFL with an anatomical approach.

RESULTS

RF ablation was successful in all patients. All but one patient continued with AAD. Four patients (22%) had recurrences of AFL. Two of them also had a recurrence of AF. Another three patients had recurrences of AF only, and finally, one patient developed an atrial tachycardia more than one year after the procedure. In conclusion, 11 patients (61%) did not experience recurrences of AF/AFL after tricuspid valve annulus (TV)-inferior caval vein (IVC) isthmus ablation with continuing antiarrhythmic drugs.

CONCLUSION

Hybrid pharmacological and ablative therapy is a safe and effective treatment for the management of patients with symptomatic AF.

Clinical benefit, survival and adverse events in patients with implantable cardioverter defibrillators: the initial Rotterdam experience

BACKGROUND

The implantable cardioverter defibrillator (ICD) has become a widely accepted therapy for patients with severe life-threatening ventricular tachyarrhythmias. The aim of this study was to illustrate the possible advantages of ICDs with respect to survival and clinical events.

METHODS AND RESULTS

Between 1998 and 2000, 92 patients (aged 58±15 years; ejection fraction 36±15%; coronary artery disease 71%) were treated with an ICD in combination with an endocardial lead system. Benefit of the ICD was estimated as the difference between total cardiac death and the projected death rate of fast ventricular tachyarrhythmias (>200 bpm), assuming that most fast ventricular tachyarrhythmias would have been fatal without termination by the ICD. Adverse events were classified according to European standards. The cardiac mortality rate was 5.5% and 9.8%, at one and two years respectively. The recurrence rate of fast VT (>200 bpm) was 22.4% and 30.2%, at one and two years respectively. The observed difference between cardiac death and projected death was very significant (p=0.002) and suggests a clear benefit from ICD implantation. Low ejection fraction (<35%) and NYHA class ≥II correlated with a higher projected death. The most common adverse event was inappropriate therapy (18%).

CONCLUSION

The results from our small series support the existing data that especially patients with poor ejection fraction (<35%) benefit from ICD implantation. The adverse event rate was low. However, inappropriate therapy remains a matter of concern. Given the high workload of correct screening and follow-up, we expect that the actual number of centres in the Netherlands permitted to implant ICDs will be unable to cope with the widening spectrum of ICD indications.