Ashish Sood MBBS, Samual Turnbull BSc, Kasun De Silva MBBS, Ashwin Bhaskaran MBBS, MSc (Int Med), Richard G. Bennett BSc, MBChB, PhD, Timothy G. Campbell BSc, PhD, Liza Thomas MBBS, PhD, Saurabh Kumar MBBS, PhD
Background
Catheter ablation (CA) is efficacious for the treatment of ventricular tachycardia (VT) in patients with structural heart disease; however, heart failure contributes to long-term mortality in this cohort. Whether CA worsens left ventricular function requires investigation.
Methods
We retrospectively analyzed 142 consecutive patients with structural heart disease undergoing CA for VT. Pre-ablation left ventricular ejection fraction (LVEF) was compared to LVEF postablation, predictors of change in LVEF were identified, and the relationship between change in LVEF and arrhythmic recurrence was assessed.
Results
Patients with ischemic cardiomyopathy (ICM) had lower pre-ablation LVEF than patients with non-ischemic cardiomyopathy (NICM) (36.2 ± 14.3% vs. 50.8 ± 12.8%, p < 0.001). There was no statistically significant change in LVEF following ablation for patients with ICM (p = 0.45) or NICM (p = 0.75). Patients with pre-ablation LVEF ≤20% experienced the largest recovery in LVEF, mean recovery 5.3% (95% CI: 0.6–10.1), p = 0.03, with LVEF recovery postablation similar in ICM and NICM patients (p = 0.69). Recovery of LVEF was associated with a decreased incidence of ventricular arrhythmia (VA) recurrence (p = 0.03) and an increased VA-recurrence-free survival (p = 0.04).
Conclusion
CA for VT does not cause a decline in LVEF among patients with structural heart disease. The subset of patients with severely impaired LVEF may experience an increase in LVEF following ablation and an associated reduction in VA recurrence.
{"title":"Impact of catheter ablation for ventricular tachycardia on left ventricular ejection fraction in patients with structural heart disease","authors":"Ashish Sood MBBS, Samual Turnbull BSc, Kasun De Silva MBBS, Ashwin Bhaskaran MBBS, MSc (Int Med), Richard G. Bennett BSc, MBChB, PhD, Timothy G. Campbell BSc, PhD, Liza Thomas MBBS, PhD, Saurabh Kumar MBBS, PhD","doi":"10.1002/joa3.70042","DOIUrl":"https://doi.org/10.1002/joa3.70042","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Catheter ablation (CA) is efficacious for the treatment of ventricular tachycardia (VT) in patients with structural heart disease; however, heart failure contributes to long-term mortality in this cohort. Whether CA worsens left ventricular function requires investigation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We retrospectively analyzed 142 consecutive patients with structural heart disease undergoing CA for VT. Pre-ablation left ventricular ejection fraction (LVEF) was compared to LVEF postablation, predictors of change in LVEF were identified, and the relationship between change in LVEF and arrhythmic recurrence was assessed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Patients with ischemic cardiomyopathy (ICM) had lower pre-ablation LVEF than patients with non-ischemic cardiomyopathy (NICM) (36.2 ± 14.3% vs. 50.8 ± 12.8%, <i>p</i> < 0.001). There was no statistically significant change in LVEF following ablation for patients with ICM (<i>p</i> = 0.45) or NICM (<i>p</i> = 0.75). Patients with pre-ablation LVEF ≤20% experienced the largest recovery in LVEF, mean recovery 5.3% (95% CI: 0.6–10.1), <i>p</i> = 0.03, with LVEF recovery postablation similar in ICM and NICM patients (<i>p</i> = 0.69). Recovery of LVEF was associated with a decreased incidence of ventricular arrhythmia (VA) recurrence (<i>p</i> = 0.03) and an increased VA-recurrence-free survival (<i>p</i> = 0.04).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>CA for VT does not cause a decline in LVEF among patients with structural heart disease. The subset of patients with severely impaired LVEF may experience an increase in LVEF following ablation and an associated reduction in VA recurrence.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The optimal indication for implantable cardioverter-defibrillator (ICD) implantation in the aging population remains a subject of debate, given the high incidence of nonarrhythmic mortality in this cohort. The authors have investigated the clinical outcomes of octogenarians undergoing ICD implantation for both primary and secondary prevention, with a focus on ICD therapies and the timing of mortality.1 Their findings suggest that while device utilization was infrequent, it preceded mortality by a significant margin. This may encourage clinicians to adopt a more aggressive approach to ICD implantation, even in elderly patients. However, several concerns warrant consideration.
A prior large-scale study evaluating the clinical implications of ICD generator replacement in the aging population reported that a substantial proportion of patients over 80 years of age succumbed before experiencing appropriate device utilization.2 The discrepancy between these findings may stem from differences in baseline patient characteristics. Could the authors provide data on the proportion of patients who received guideline-directed medical therapy, which is known to mitigate arrhythmic events? Additionally, how many patients underwent catheter ablation for ventricular arrhythmias? Given that aggressive catheter ablation can reduce arrhythmic burden and thereby decrease the need for ICD intervention,3 this information would be critical for contextualizing the study's findings.
Furthermore, the exclusion of patients with an observation period of fewer than 30 days raises concerns,1 as these individuals may be at particularly high risk for arrhythmic events. Their omission could potentially bias the results and limit the generalizability of the study.
In the present study, approximately 20% of patients received cardiac resynchronization therapy (CRT),1 which promotes cardiac reverse remodeling and may reduce the incidence of ventricular arrhythmias. The impact of CRT on preventing appropriate ICD utilization likely differs from that observed in patients with ICD implantation alone. Clarification on this point would enhance the interpretation of the findings.
Finally, the risk of device-related complications, including bleeding and infection, remains a significant concern, particularly in elderly patients with multiple comorbidities.4 These risks must be carefully weighed against the potential benefits of ICD implantation in this population.
The authors declare no conflict of interest.
{"title":"How to indicate implantable cardioverter-defibrillator in the aging population","authors":"Risako Orita, Naoya Kataoka MD, PhD, Teruhiko Imamura MD, PhD","doi":"10.1002/joa3.70038","DOIUrl":"https://doi.org/10.1002/joa3.70038","url":null,"abstract":"<p>To Editor,</p><p>The optimal indication for implantable cardioverter-defibrillator (ICD) implantation in the aging population remains a subject of debate, given the high incidence of nonarrhythmic mortality in this cohort. The authors have investigated the clinical outcomes of octogenarians undergoing ICD implantation for both primary and secondary prevention, with a focus on ICD therapies and the timing of mortality.<span><sup>1</sup></span> Their findings suggest that while device utilization was infrequent, it preceded mortality by a significant margin. This may encourage clinicians to adopt a more aggressive approach to ICD implantation, even in elderly patients. However, several concerns warrant consideration.</p><p>A prior large-scale study evaluating the clinical implications of ICD generator replacement in the aging population reported that a substantial proportion of patients over 80 years of age succumbed before experiencing appropriate device utilization.<span><sup>2</sup></span> The discrepancy between these findings may stem from differences in baseline patient characteristics. Could the authors provide data on the proportion of patients who received guideline-directed medical therapy, which is known to mitigate arrhythmic events? Additionally, how many patients underwent catheter ablation for ventricular arrhythmias? Given that aggressive catheter ablation can reduce arrhythmic burden and thereby decrease the need for ICD intervention,<span><sup>3</sup></span> this information would be critical for contextualizing the study's findings.</p><p>Furthermore, the exclusion of patients with an observation period of fewer than 30 days raises concerns,<span><sup>1</sup></span> as these individuals may be at particularly high risk for arrhythmic events. Their omission could potentially bias the results and limit the generalizability of the study.</p><p>In the present study, approximately 20% of patients received cardiac resynchronization therapy (CRT),<span><sup>1</sup></span> which promotes cardiac reverse remodeling and may reduce the incidence of ventricular arrhythmias. The impact of CRT on preventing appropriate ICD utilization likely differs from that observed in patients with ICD implantation alone. Clarification on this point would enhance the interpretation of the findings.</p><p>Finally, the risk of device-related complications, including bleeding and infection, remains a significant concern, particularly in elderly patients with multiple comorbidities.<span><sup>4</sup></span> These risks must be carefully weighed against the potential benefits of ICD implantation in this population.</p><p>The authors declare no conflict of interest.</p>","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Technological development has improved the battery longevity of cardiac implantable electronic devices (CIEDs). However, there have been no reports on the extent of the improvement in battery longevity in the real world.
Methods
Patients who underwent CIED exchanges from February 2006 to June 2023 were included in this study. The actual battery longevity calculated from the implantation date to the battery replacement date and the predicted battery longevity based on manufacturer reports were investigated. All patients were divided into five groups according to their initial implantation dates. After excluding the first and last groups, the data among the middle three groups (P1, P2, P3) were compared.
Results
A total of 3119 patients (pacemakers [PMs], 2138; ICDs, 477; cardiac resynchronization therapy pacemakers [CRTPs], 121; cardiac resynchronization therapy defibrillators [CRTDs], 383) were enrolled in this study. The predicted device longevity improved over time for all devices, but in recent analyses, it has been overestimated compared to the actual device longevity for PMs, ICDs, and CRTPs. The actual device longevity of PMs, ICDs, and CRTDs exhibited an extension in the early two periods (P1 vs. P2), but no extension was observed in the most recent two periods (P2 vs. P3). CRTPs showed no improvement in any of the periods.
Conclusion
The battery longevity has improved by only about 1 year over the past nearly 15 years. Moreover, the discrepancy between the predicted and actual battery longevity suggests that a reevaluation of the methods for calculating the predicted battery longevity may be necessary.
{"title":"Advancements in BATTERY longevity of cardiac implantable electronic devices from real-world data: BATTERY study","authors":"Maiko Kuroda MD, Michio Nagashima MD, Masataka Narita MD, Wataru Sasaki MD, Naomichi Tanaka MD, PhD, Kazuhisa Matsumoto MD, PhD, Tsukasa Naganuma MD, Hitoshi Mori MD, PhD, Yoshifumi Ikeda MD, PhD, Kengo Korai MD, Masato Fukunaga MD, Kenichi Hiroshima MD, Kenji Ando MD, Ritsushi Kato MD, PhD","doi":"10.1002/joa3.70041","DOIUrl":"https://doi.org/10.1002/joa3.70041","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Technological development has improved the battery longevity of cardiac implantable electronic devices (CIEDs). However, there have been no reports on the extent of the improvement in battery longevity in the real world.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Patients who underwent CIED exchanges from February 2006 to June 2023 were included in this study. The actual battery longevity calculated from the implantation date to the battery replacement date and the predicted battery longevity based on manufacturer reports were investigated. All patients were divided into five groups according to their initial implantation dates. After excluding the first and last groups, the data among the middle three groups (P1, P2, P3) were compared.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 3119 patients (pacemakers [PMs], 2138; ICDs, 477; cardiac resynchronization therapy pacemakers [CRTPs], 121; cardiac resynchronization therapy defibrillators [CRTDs], 383) were enrolled in this study. The predicted device longevity improved over time for all devices, but in recent analyses, it has been overestimated compared to the actual device longevity for PMs, ICDs, and CRTPs. The actual device longevity of PMs, ICDs, and CRTDs exhibited an extension in the early two periods (P1 vs. P2), but no extension was observed in the most recent two periods (P2 vs. P3). CRTPs showed no improvement in any of the periods.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The battery longevity has improved by only about 1 year over the past nearly 15 years. Moreover, the discrepancy between the predicted and actual battery longevity suggests that a reevaluation of the methods for calculating the predicted battery longevity may be necessary.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rungroj Krittayaphong MD, Sukrit Treewaree MD, Ahthit Yindeengam BSc, Gregory Y. H. Lip MD
Background
The objective of this study was to compare the risk of estimated glomerular filtration rate (eGFR) decline between atrial fibrillation (AF) patients with direct oral anticoagulants (DOACs) and warfarin.
Methods
We studied patients with nonvalvular AF from a prospective multicenter national AF registry in Thailand. Patients with missing eGFR data or eGFR less than 30 mL/min/1.73 m2 were excluded. Follow-up data including eGFR were collected every 6 months until 3 years. eGFR decline was assessed by eGFR slope. We compared eGFR slope between patients who received DOACs and warfarin at baseline. In the warfarin group, we assessed the impact of good anticoagulation control by time in the therapeutic range (TTR).
Results
A total of 1708 patients were studied (mean age 68.1 years; 42.6% female). Patients with DOACs had a significantly slower rate of eGFR decline compared to warfarin. The eGFR slope was 2.32 mL/min/1.73 m2 per year in the warfarin group (95% CI: 3.09 to 1.55), and 1.31 mL/min/1.73 m2 per year in the DOAC group (95% CI: 1.97 to 0.64). The effect of OAC type on the eGFR slope remained significant even after the adjustment of baseline variables including baseline eGFR. There was no difference in GFR decline as reflected by eGFR slope when comparing warfarin patients with TTR <65% and ≥65%.
Conclusion
In this prospective cohort of Asian patients with AF, DOACs were associated with a slower rate of eGFR decline when compared with warfarin. In the latter group, this was irrespective of the quality of anticoagulation control.
{"title":"Renal function decline in Asian patients with atrial fibrillation with warfarin and non-vitamin K antagonist oral anticoagulants: A report from the COOL-AF registry","authors":"Rungroj Krittayaphong MD, Sukrit Treewaree MD, Ahthit Yindeengam BSc, Gregory Y. H. Lip MD","doi":"10.1002/joa3.70037","DOIUrl":"https://doi.org/10.1002/joa3.70037","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The objective of this study was to compare the risk of estimated glomerular filtration rate (eGFR) decline between atrial fibrillation (AF) patients with direct oral anticoagulants (DOACs) and warfarin.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We studied patients with nonvalvular AF from a prospective multicenter national AF registry in Thailand. Patients with missing eGFR data or eGFR less than 30 mL/min/1.73 m<sup>2</sup> were excluded. Follow-up data including eGFR were collected every 6 months until 3 years. eGFR decline was assessed by eGFR slope. We compared eGFR slope between patients who received DOACs and warfarin at baseline. In the warfarin group, we assessed the impact of good anticoagulation control by time in the therapeutic range (TTR).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 1708 patients were studied (mean age 68.1 years; 42.6% female). Patients with DOACs had a significantly slower rate of eGFR decline compared to warfarin. The eGFR slope was 2.32 mL/min/1.73 m<sup>2</sup> per year in the warfarin group (95% CI: 3.09 to 1.55), and 1.31 mL/min/1.73 m<sup>2</sup> per year in the DOAC group (95% CI: 1.97 to 0.64). The effect of OAC type on the eGFR slope remained significant even after the adjustment of baseline variables including baseline eGFR. There was no difference in GFR decline as reflected by eGFR slope when comparing warfarin patients with TTR <65% and ≥65%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>In this prospective cohort of Asian patients with AF, DOACs were associated with a slower rate of eGFR decline when compared with warfarin. In the latter group, this was irrespective of the quality of anticoagulation control.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>Defibrillation threshold (DFT) testing has long been debated in the field of implantable cardioverter defibrillator (ICD) management, with contemporary practice leaning towards its selective rather than routine use. The study by Narita et al.<span><sup>1</sup></span> presents a compelling case where DFT testing played a pivotal role in evaluating the function of an ICD lead with very high shock impedance, ultimately guiding clinical decision-making. Their findings provide valuable insights into the evolving role of impedance monitoring and highlight the limitations of low-voltage subthreshold measurement (LVSM) in assessing true shock impedance (TSI).</p><p>The report describes a case in which an Endotak Reliance 0296 lead exhibited a progressive increase in shock impedance over 11 years, eventually surpassing 200 Ω. This raised concerns about potential lead dysfunction, necessitating a clinical approach to determine the safety, and efficacy of continued use. The authors convincingly demonstrate that despite the alarmingly high impedance recorded by LVSM, the lead remained functional, as confirmed by successful DFT testing with a true shock impedance of 103 Ω.</p><p>The discrepancy between LVSM and TSI is a critical finding. LVSM has been widely adopted for its non-invasive, pain-free nature, but, as shown in this case, it may not always provide an accurate reflection of true lead function. The authors postulate that lead encapsulation and environmental stress cracking may have contributed to the impedance increase. These factors, along with the known risk of calcification in GORE-expanded polytetrafluoroethylene (ePTFE)-coated coils, raise important considerations for long-term lead surveillance.</p><p>DFT testing has been largely deemphasized in recent years due to concerns about procedural risks and limited impact on patient outcomes in standard ICD implants.<span><sup>2</sup></span> However, this case underscores its utility in specific clinical scenarios. In the presence of suspected lead dysfunction, particularly with high-voltage impedance concerns, DFT testing can provide a definitive functional assessment of lead replacement and decrease the LVSM to the normal range, making it easy to detect future lead fractures using LVSM. Furthermore, prior study suggests that a commanded low-energy impedance test (0.1 Joule) is a safer and more reliable method for identifying and verifying potential open shock line conditions compared to high-energy shock testing.<span><sup>3</sup></span> This raises the possibility that a combined approach using both low- and high-energy shocks could enhance the assessment of lead function in such cases. By incorporating both strategies, clinicians may improve diagnostic accuracy and ensure the long-term functionality of ICD leads while minimizing unnecessary interventions. The study by Narita et al. presents a well-documented case highlighting the complexities of ICD lead impedance monitoring. Their findings sup
{"title":"Editorial to “Can lead damage be ruled out using defibrillation threshold testing in patients with very high-impedance shock leads?”","authors":"Taro Temma MD, PhD, Toshihisa Anzai MD, PhD","doi":"10.1002/joa3.70040","DOIUrl":"https://doi.org/10.1002/joa3.70040","url":null,"abstract":"<p>Defibrillation threshold (DFT) testing has long been debated in the field of implantable cardioverter defibrillator (ICD) management, with contemporary practice leaning towards its selective rather than routine use. The study by Narita et al.<span><sup>1</sup></span> presents a compelling case where DFT testing played a pivotal role in evaluating the function of an ICD lead with very high shock impedance, ultimately guiding clinical decision-making. Their findings provide valuable insights into the evolving role of impedance monitoring and highlight the limitations of low-voltage subthreshold measurement (LVSM) in assessing true shock impedance (TSI).</p><p>The report describes a case in which an Endotak Reliance 0296 lead exhibited a progressive increase in shock impedance over 11 years, eventually surpassing 200 Ω. This raised concerns about potential lead dysfunction, necessitating a clinical approach to determine the safety, and efficacy of continued use. The authors convincingly demonstrate that despite the alarmingly high impedance recorded by LVSM, the lead remained functional, as confirmed by successful DFT testing with a true shock impedance of 103 Ω.</p><p>The discrepancy between LVSM and TSI is a critical finding. LVSM has been widely adopted for its non-invasive, pain-free nature, but, as shown in this case, it may not always provide an accurate reflection of true lead function. The authors postulate that lead encapsulation and environmental stress cracking may have contributed to the impedance increase. These factors, along with the known risk of calcification in GORE-expanded polytetrafluoroethylene (ePTFE)-coated coils, raise important considerations for long-term lead surveillance.</p><p>DFT testing has been largely deemphasized in recent years due to concerns about procedural risks and limited impact on patient outcomes in standard ICD implants.<span><sup>2</sup></span> However, this case underscores its utility in specific clinical scenarios. In the presence of suspected lead dysfunction, particularly with high-voltage impedance concerns, DFT testing can provide a definitive functional assessment of lead replacement and decrease the LVSM to the normal range, making it easy to detect future lead fractures using LVSM. Furthermore, prior study suggests that a commanded low-energy impedance test (0.1 Joule) is a safer and more reliable method for identifying and verifying potential open shock line conditions compared to high-energy shock testing.<span><sup>3</sup></span> This raises the possibility that a combined approach using both low- and high-energy shocks could enhance the assessment of lead function in such cases. By incorporating both strategies, clinicians may improve diagnostic accuracy and ensure the long-term functionality of ICD leads while minimizing unnecessary interventions. The study by Narita et al. presents a well-documented case highlighting the complexities of ICD lead impedance monitoring. Their findings sup","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Rehan Zahid MBBS, Syed Tawassul Hassan MBBS, Muhammad Shaheer Bin Faheem MBBS, Aleeza Rehman MBBS, Syed Muhammad Ali MD
<p>We read the article “Implantable cardiac defibrillator outcomes in octogenarians” and appreciate the authors, Stringer et al., for their efforts in examining the outcomes of implantable cardiac defibrillator (ICD) in overlooked elderly population (80 or <) having increased susceptibility to sudden cardiac death (SCD).<span><sup>1</sup></span> We highly commend their work for analyzing outcomes like mortality, frailty, and usage frequency related to ICD treatment and acknowledge their contribution to the ongoing discussion of ICD therapy in older adults. However, we found several methodological gaps that can significantly affect this study's findings.</p><p>Firstly, the study relied on univariate statistical tests without any multivariate adjustments. This can fail to provide the accurate relationship of covariates such as demographics that include age and gender and comorbidities like hypertension, diabetes, and atrial fibrillation with the study outcomes, excluding necessary confounders that can significantly impact the effect of ICD and study conclusions.<span><sup>2</sup></span> Although the Dalhousie frailty score helps in risk stratification and better frailty assessment in octogenarians, it requires detailed data on patients' health conditions, while the study documented a significant loss of device records and follow-up data that can lead to inaccurate findings. Further, it requires subjective clinical judgment rather than relying on medical records, as in this study. Authors had assumed the patients to be alive who had a clinical or emergency visit in the last 3 months of the study, inducing misclassification bias as the patients who were not able to report due to any reason might be classified as dead, distorting mortality outcomes. Among patients in the primary prevention group, a set threshold of 188 bpm for ventricular tachycardia (VT)/Ventricular fibrillation (VF) is not suitable for those who experience severe arrhythmias at lower cardiac rates, and a nonindividualized programming approach can cause excessive shocks affecting the quality of life of these patients.<span><sup>3</sup></span> Also, aggressive ATP usage before shocks can delay the needed shocks for patients with prolonged ventricular arrhythmias.<span><sup>3</sup></span> A total of five patients (6.3%) were classified as critically frail; this underpowered subgroup analysis can increase the risk of type 2 errors, undermining the outcomes of this study.<span><sup>4</sup></span> Women have a higher risk of procedural and postimplantation ICD-related complications, but only 14% of the total population of this study were female, limiting the generalizability of findings toward the female population.<span><sup>5</sup></span></p><p>Lastly, to control confounders, we recommend using multivariable regressions and adapting the electronic frailty index designed for retrospective study designs to enhance the data's reliability. However, misclassification bias can be avoided b
{"title":"Implantable cardiac defibrillator outcomes in octogenarians","authors":"Muhammad Rehan Zahid MBBS, Syed Tawassul Hassan MBBS, Muhammad Shaheer Bin Faheem MBBS, Aleeza Rehman MBBS, Syed Muhammad Ali MD","doi":"10.1002/joa3.70039","DOIUrl":"https://doi.org/10.1002/joa3.70039","url":null,"abstract":"<p>We read the article “Implantable cardiac defibrillator outcomes in octogenarians” and appreciate the authors, Stringer et al., for their efforts in examining the outcomes of implantable cardiac defibrillator (ICD) in overlooked elderly population (80 or <) having increased susceptibility to sudden cardiac death (SCD).<span><sup>1</sup></span> We highly commend their work for analyzing outcomes like mortality, frailty, and usage frequency related to ICD treatment and acknowledge their contribution to the ongoing discussion of ICD therapy in older adults. However, we found several methodological gaps that can significantly affect this study's findings.</p><p>Firstly, the study relied on univariate statistical tests without any multivariate adjustments. This can fail to provide the accurate relationship of covariates such as demographics that include age and gender and comorbidities like hypertension, diabetes, and atrial fibrillation with the study outcomes, excluding necessary confounders that can significantly impact the effect of ICD and study conclusions.<span><sup>2</sup></span> Although the Dalhousie frailty score helps in risk stratification and better frailty assessment in octogenarians, it requires detailed data on patients' health conditions, while the study documented a significant loss of device records and follow-up data that can lead to inaccurate findings. Further, it requires subjective clinical judgment rather than relying on medical records, as in this study. Authors had assumed the patients to be alive who had a clinical or emergency visit in the last 3 months of the study, inducing misclassification bias as the patients who were not able to report due to any reason might be classified as dead, distorting mortality outcomes. Among patients in the primary prevention group, a set threshold of 188 bpm for ventricular tachycardia (VT)/Ventricular fibrillation (VF) is not suitable for those who experience severe arrhythmias at lower cardiac rates, and a nonindividualized programming approach can cause excessive shocks affecting the quality of life of these patients.<span><sup>3</sup></span> Also, aggressive ATP usage before shocks can delay the needed shocks for patients with prolonged ventricular arrhythmias.<span><sup>3</sup></span> A total of five patients (6.3%) were classified as critically frail; this underpowered subgroup analysis can increase the risk of type 2 errors, undermining the outcomes of this study.<span><sup>4</sup></span> Women have a higher risk of procedural and postimplantation ICD-related complications, but only 14% of the total population of this study were female, limiting the generalizability of findings toward the female population.<span><sup>5</sup></span></p><p>Lastly, to control confounders, we recommend using multivariable regressions and adapting the electronic frailty index designed for retrospective study designs to enhance the data's reliability. However, misclassification bias can be avoided b","PeriodicalId":15174,"journal":{"name":"Journal of Arrhythmia","volume":"41 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joa3.70039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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