Rate Of Inappropriate Therapy Research Articles

Implantable cardioverter defibrillator therapy in paediatric patients for primary vs. secondary prevention.

The decisions about placing an ICD in a child are more difficult than in an adult due to longer expected lifespan and the complication risk. Young patients gain the most years from ICDs, despite higher risk of device-related complications. The secondary prevention ICD indication is clear, and device is implanted regardless of potential complications. For primary prevention, risk of sudden cardiac death and complications need to be evaluated. We aimed to compare outcomes for primary and secondary prevention ICDs. Retrospective nationwide cohort study including paediatric patients identified from the Danish ICD registry with ICD implanted at an age ≤ 15 from 1982-21. Demographics, complications (composite of device-related infections or lead-failure requiring re-operation, mortality because of arrhythmia, or unknown cause), and mortality were retrieved from medical charts. Endpoint was appropriate therapy (shock or anti-tachycardia pacing for ventricular tachycardia or fibrillation). Of 72 receiving an ICD, the majority had channelopathies (n = 34) or structural heart diseases (n = 28). ICDs were implanted in 23 patients for primary prevention and 49 for secondary prevention, at median ages of 13.8 and 11.6 years (P-value 0.01), respectively. Median follow-up was 9.0 (interquartile ranges: 4.7-13.5) years. The 10-year cumulative incidence of first appropriate therapy was 70%, with complication and inappropriate therapy rates at 41% and 15%, respectively. No difference was observed between prevention groups for all outcomes. Six patients died during follow-up. In children, two-thirds are secondary prevention ICDs. Children have higher appropriate therapy and complication rates than adults, while the inappropriate therapy rate was low.

The effect of Remote Monitor vs Standard of Care therapy on outcome A systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Project no. RRF-2.3.1-21-2022-00004 (MILAB) has been implemented with the support provided by the European Union. Background Remote monitoring (RM) in heart failure (HF) patients with cardiac implantable electronic devices (CIED) is a reliable approach to strictly following the device-specific and heart failure-related parameters. Despite a few positive outcome data, results are incomprehensive. Aims We aimed to assess the benefit of continuous RM vs. standard of care (SoC) in the reduction of all-cause mortality, heart failure hospitalization (HF), and cardiovascular-related hospitalization (CV), and inappropriate therapy. Methods A systematic review and meta-analysis of randomized controlled trials (RCT) testing RM vs. SoC for the management of HF patients were performed. Endpoints were all-cause mortality, CV- and HF hospitalizations and inappropriate therapy. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated. CENTRAL, EMBASE and MEDLINE were searched up to 21th of December 2021. Only randomized controlled studies were included. Results Fourteen RCTs that enrolled a total of 8370 patients were identified to evaluate all-cause mortality, resulting in an OR 0.88 (95% CI 0.75 to 1.03). When CV - and HF hospitalizations were assessed, there were no differences between the RM group and SoC group, and the OR was 0.93 (95% CI 0.82 to 1.05) and 0.95 (95% CI 0.75 to 1.19), respectively.Moreover RM did not have an effect on the rate of inappropriate therapy, OR was 0.73. (95% CI 0.30 to 1.81). Conclusions RM proved to be non-inferior in reducing all-cause mortality, CV- and HF hospitalization and rate of inappropriate therapy when compared to standard of care despite of the heterogeneous study cohorts and unstandardized alert actions.

Long-Term clinical outcomes of subcutaneous implantable defibrillator therapy in patients with heart failure and reduced ejection fraction: a single center experience

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): P. JACON consultant: Boston Scientific France Introduction The implantable cardioverter defibrillator (ICD) is the most effective therapy for prevention of sudden cardiac death in high-risk patients with heart failure and reduced ejection fraction (HFrEF). The subcutaneous implantable cardioverter defibrillator (S-ICD) has been considered as a comparable and relatively safer alternative to transvenous ICD in patients (pts) without pacing indication. Purpose Our aim was to assess the clinical "real-life" outcomes of S-ICD in patients with HFrEF and primary or secondary prevention, over a long-term follow-up (FU) period after S-ICD implantation. Methods All pts with HFrEF (left ventricular ejection fraction ≤35%) implanted with a S-ICD and a FU above 6 months were included in a cross-sectional monocentric study. Pts were followed by remote monitoring. Results 88 pts were included (52 ± 12.8 years old, male 87.5%). Indications were: primary 92% and secondary 8% prevention (ischemic cardiopathy 46%; dilated 46%; hypertrophic 5%; congenital 2%; valvular 1%). The mean left ventricular ejection fraction was 27%. 9 pts had a previous transvenous ICD implanted, but required revision because of infection or lead defects. The mean FU period was 33 ± 18 months with a mortality rate of 10% (S-ICD-related death secondary to inappropriate (inap) shocks for one patient). 5 pts underwent S-ICD system extraction after a mean FU period of 30 ± 21 months. Reasons were infectious complication (1 pt), pacing indication (2 pts) and S-ICD lead dysfunction (2 pts). Extraction after heart transplant was performed in 4 pts. During FU, 18 pts (20.5%) experienced at least one therapy: 8 pts (9%) with appropriate (ap) (3.3% per year) and 11 pts (12%) with inap shocks (4.36% per year). A total number of 24 ap shocks have been observed (3 ± 4 ap shocks per patient, several shocks for 3 pts), the first shock occurred after a mean FU period of 24 ± 14 months. 2 pts were referred to VT ablation and no recurrence of events was observed after medical therapy modification for the other pts. For the 11 pts with inap shocks, time to the first event was 19 ± 20 months. Reasons were: supraventricular arrhythmias (18%), T wave (36%) and noise (54%) oversensing. There was 1.8 ± 1.6 shock per patient with several shocks for 4 pts. Among pts with inap shocks, 2 pts required S-ICD system extraction, 1 pt died, while reprogramming and medical therapy options were efficient in other pts. Conclusion In pts with HFrEF at high risk of sudden cardiac death, S-ICD has proven to be effective in treating ventricular arrhythmias. However, more investigations must be conducted to explain the real-life high rate of inappropriate therapies. Abstract Figure. Survival-free from therapies curve

Long-term follow-up of adult patients with congenital heart disease and an implantable cardioverterdefibrillator.

Sudden cardiac death is common in the adult congenital heart disease (ACHD) population. Knowledge and experience about the use of implantable cardioverter defibrillators (ICD) in ACHD patients is very limited. We aimed to characterize a cohort of patients with ACHD and ICDs. Thirty consecutive ACHD patients submitted to an ICD implantation in a single tertiary center were evaluated. Data on baseline clinical features, heart defect, indication for ICD, type of device, appropriate therapies, ICD-related complication, and mortality during follow-up were collected. Of the 30 patients,56.7% received appropriate therapies due to ventricular tachycardia (VT) or ventricular fibrillation (VF). The rate of inappropriate therapies and device-related complications was 33.3%. Secondary prevention and primary prevention patients with class I indications for ICD had more appropriate therapies than complication, but this relationship was reversed for patients with class II indications. Remote monitoring played an important role in diagnosing new atrial arrhythmias before scheduled visits in 46.2% of patients, leading to a change in medication. VT/VF episodes were associated with a composite of death, cardiac transplantation, and hospital admission (OR 13.0; 95% CI: 2.1-81.5). ICDs are not only useful in preventing SCD, but also have a major role in diagnosing atrial tachyarrhythmias ahead of scheduled visits. Although improvements in ICD technology might reduce complications and inappropriate therapies, adequate selection of candidates for primary prevention still remains difficult because of the lack of clear indications.

P3261SVT discrimination algorithms significantly reduce the rates of inappropriate therapies in the setting of modern day delayed high-rate detection programming

P3261SVT discrimination algorithms significantly reduce the rates of inappropriate therapies in the setting of modern day delayed high-rate detection programming

Persistence of ICD indication at the time of replacement in patients with initial implant for primary prevention indication: Effect on subsequent ICD therapies

BackgroundIndication to implantable cardioverter defibrillator (ICD) for primary prevention of sudden death relies on left ventricular ejection fraction (LVEF). We measured the proportion of patients in whom indication to ICD persisted at the time of generator replacement (GR) and searched for predictors of appropriate therapies after GR. MethodsWe identified all consecutive patients who had received an ICD at our hospital, for LVEF ≤35% and no previous arrhythmias or unexplained syncope. Then, we included the 166 patients who outlived their first device and underwent GR. ResultsAt the time of GR (mean follow-up 59 ± 20 months), ICD indication (i.e. LVEF ≤35% or previously treated ventricular arrhythmias) persisted in 114 (69%) patients. After GR, appropriate ICD therapies were delivered in 30 (26%) patients with persistent ICD indication and in 12 (23%) of the remaining patients (p = 0.656). Nonetheless, the annual rate of therapies was higher in the first group (1.08 versus 0.53 events/year; p < 0.001), as well as the rate of inappropriate therapies (0.03 versus 0 events/year; p = 0.031). The only independent predictor of appropriate ICD therapies after GR was the rate of shocks received before replacement (Hazard Ratio: 1.41; 95% confidence interval: 1.01–1.96; p = 0.041). ConclusionIn heart failure with reduced LVEF, ICD indication persisted at the time of GR in 69% of patients. However, even in the absence of persistent ICD indication at GR, the risk of recurrence of arrhythmic events was not null.

Abstract 16941: Device Therapies Among Patients Receiving Primary Prevention Implantable Cardioverter Defibrillators (ICDs): Insights From the Cardiovascular Research Network Longitudinal Study of ICDs

Introduction: Primary prevention implantable cardioverter defibrillators (ICDs) reduce mortality in select patients with left ventricular systolic dysfunction (LVSD). The occurrence of device therapies after ICD implantation in contemporary clinical practice is not well described, especially in patient subgroups designated in the Centers for Medicare and Medicaid Services (CMS) 2005 Coverage with Evidence Development (CED). Methods: The Longitudinal Study of ICDs assessed rates and correlates of device therapies (overall and those requiring shock) up to 3 years post-implant among 2540 patients with LVSD receiving first-time primary prevention ICDs in 7 US health care systems from 2006-2009. Implant data from the National Cardiovascular Data Registry ICD Registry were linked to electronic longitudinal health care system data and a novel centrally adjudicated repository of device therapies abstracted from medical records. Proportional hazard models evaluated associations with device therapies by appropriateness, adjusted for demographic and clinical factors. Results: Subjects were 26% women, 35% &lt;65 years old, and 59% non-Hispanic white. Over a mean 26 months, 738 (29.1%) received at least 1 therapy (median 2). Estimated 3-year risk of any device therapy was 36% (24% appropriate, 12% inappropriate); for therapy requiring shock, corresponding values were 24%, 14%, 9%. The rate of appropriate therapy was higher in men than women (adjusted hazard ratio 1.84, 95% confidence interval 1.43-2.35). The rate of inappropriate therapy was higher for subjects &lt;65 than for those &gt;=65 years (1.40, 1.04-1.88), and lower among 2009 implants compared to 2006 (0.66, 0.46-0.95). Regarding the 3 CMS CED patient subgroups, neither ejection fraction nor heart failure symptom severity was associated with device therapy; for LVSD etiology, the rate of inappropriate therapy was nominally but not significantly higher among subjects with non-ischemic cardiomyopathy of &lt; 9 months duration (1.38, 0.88-2.18). Conclusions: In a representative cohort of primary prevention ICD patients in usual care, rates of device therapies were somewhat lower than in landmark trials, differed by some patient characteristics, but did not differ meaningfully for CMS CED subgroups.

Are dual-chamber implantable cardioverter-defibrillators really better than single-chamber ones? A systematic review and meta-analysis

Although dual-chamber (DC) cardioverter defibrillators (ICDs) offer theoretical advantage over single-chamber (SC) ICDs, clinical studies showed conflicting results. The aim of this systematic review and meta-analysis was to compare DC and SC ICDs. A systematic search of publications in PubMed, Embase, and the Cochrane Library without language restriction was performed. Randomized or nonrandomized controlled studies that compared DC and SC ICDs were included. Six randomized studies including 2,388 patients and 14 nonrandomized studies including 113,931 patients were identified. No difference in mortality was observed between DC and SC ICDs recipients in randomized studies. In nonrandomized studies, higher mortality was shown in DC group. There was no difference in the rate of inappropriate therapy between the DC and SC group after pooling the results from randomized studies as well as nonrandomized studies. More complications were observed with DC ICDs recipients. DC ICDs showed no conclusive superiority over SC ICDs. Without indications for antibradycardia therapy, SC ICDs seem to be the preferred selection.

Reduction of the Inappropriate ICD Therapies by Implementing a New Fuzzy Logic–Based Diagnostic Algorithm

The aim of the study was to analyze the value of a completely new fuzzy logic-based detection algorithm (FA) in comparison with arrhythmia classification algorithms used in existing ICDs in order to demonstrate whether the rate of inappropriate therapies can be reduced. On the basis of the RR intervals database containing arrhythmia events and controls recordings from the ICD memory a diagnostic algorithm was developed and tested by a computer program. This algorithm uses the same input signals as existing ICDs: RR interval as the primary input variable and two variables derived from it, onset and stability. However, it uses 15 fuzzy rules instead of fixed thresholds used in existing devices. The algorithm considers 6 diagnostic categories: (1) VF (ventricular fibrillation), (2) VT (ventricular tachycardia), (3) ST (sinus tachycardia), (4) DAI (artifacts and heart rhythm irregularities including extrasystoles and T-wave oversensing-TWOS), (5) ATF (atrial and supraventricular tachycardia or fibrillation), and 96) NT (sinus rhythm). This algorithm was tested on 172 RR recordings from different ICDs in the follow-up of 135 patients. All diagnostic categories of the algorithm were present in the analyzed recordings: VF (n = 35), VT (n = 48), ST (n = 14), DAI (n = 32), ATF (n = 18), NT (n = 25). Thirty-eight patients (31.4%) in the studied group received inappropriate ICD therapies. In all these cases the final diagnosis of the algorithm was correct (19 cases of artifacts, 11 of atrial fibrillation and 8 of ST) and fuzzy rules algorithm implementation would have withheld unnecessary therapies. Incidence of inappropriate therapies: 3 vs. 38 (the proposed algorithm vs. ICD diagnosis, respectively) differed significantly (p < 0.05). VT/VF were detected correctly in both groups. Sensitivity and specificity were calculated: 100%, 97.8%, and 100%, 72.9% respectively for FA and tested ICDs recordings (p < 0.05). Diagnostic performance of the proposed fuzzy logic based algorithm seems to be promising and its implementation could diminish ICDs inappropriate therapies. We found FA usefulness in correct diagnosis of sinus tachycardia, atrial fibrillation and artifacts in comparison with tested ICDs.

Implantable cardioverter‐defibrillators: a long‐term view

No long-term data on implantable cardioverter-defibrillators (ICDs) exist in Australasia. We examined all patients receiving a new ICD implant at Wellington Hospital between January 2001 and December 2005 to determine long-term outcomes in this patient population. Follow-up data were collected and Kaplan-Meier curves were constructed for survival and long-term outcomes, and Cox proportional hazard model was used for calculation of hazard ratio. In the study period, 138 new ICDs were implanted, and the mean follow-up time was 84 ± 16 months. Patients were predominantly male (76%), 75% were European, 20% were Maori. Median age was 59 years (range 16-80 years). In 47% of patients, there was an ischaemic substrate. A secondary-prevention indication was present in 77%. The 7-year survival rate was 72%. No difference in mortality was observed between primary- and secondary-prevention groups. The 7-year appropriate therapy rate was 55%. The appropriate shock rate was greater in secondary prevention than in primary-prevention patients was observed (hazard ratio = 2.11, 95% confidence interval 1.16-3.85, P= 0.01). Over the study period, inappropriate therapy rate was 25%. This was more common in patients with prior atrial fibrillation (hazard ratio = 3.57, 95% confidence interval 1.80-7.09, P < 0.001). The median device longevity was 6.8 years. This is the first long-term follow-up study of ICD patients in New Zealand. We observed a low mortality rate when compared with other published registries, but a similar rate of both appropriate and inappropriate shock therapy.

High incidence of appropriate and inappropriate ICD therapies in children and adolescents with implantable cardioverter defibrillator.

Appropriate and inappropriate therapies of implantable cardioverter defibrillators have a major impact on morbidity and quality of life in ICD recipients, but have not been systematically studied in children and young adults during long-term follow-up. ICD implantation was performed in 20 patients at the mean age of 16 +/- 6 years, 11 of which had prior surgical repair of a congenital heart defect, 9 patients had other cardiac diseases. Implant indications were aborted sudden cardiac death in six patients, recurrent ventricular tachycardia in 9 patient, and syncope in 5 patients. Epicardial implantation was performed in 6 and transvenous implantation in 14 patients. Incidence, reasons and predictors (age, gender, repaired congenital heart disease, history of supraventricular tachycardia, and epicardial electrode system) of appropriate and inappropriate ICD therapies were analyzed during a mean follow-up period of 51 +/- 31 months range 18-132 months. There were a total 239 ICD therapies in 17 patients (85%) with a therapy rate of 2.8 per patient-years of follow-up. 127 (53%) ICD therapies in 15 (75%) patients were catagorized as appropriate and 112 (47%) therapies in 10 (50%) patients as inappropriate, with a rate of 1.5 appropriate and 1.3 inappropriate ICD therapies per patient-years of follow-up. Time to first appropriate therapy was 16 +/- 18 months. Appropriate therapies were caused by ventricular fibrillation in 29 and ventricular tachycardia in 98 episodes. Termination was successful by antitachycardia pacing in 4 (3%) and by shock therapy in 123 episodes (97%). Time to first inappropriate therapy was 16 +/- 17 months. Inappropriate therapies were caused by supraventricular tachycardia in 77 (69%), T wave oversensing in 19 (17%), and electrode defect in 16 episodes (14%). It caused shocks in 87 (78%) and only antitachycardia pacing in 25 episodes (22%). No clinical variable could be identified as predictor of either appropriate or inappropriate ICD therapies. There is a high rate of ICD therapies in young ICD recipients, the majority of which occur during early follow-up. The rate of inappropriate therapies is as high as 47% and is caused by supraventricular tachycardia and electrode complications in the majority of cases. Prospective trials are required to establish preventative strategies of ICD therapies in this young patient population.