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In 2022 and 2023, Medtronic recalled implantable defibrillators because they may deliver less than full-energy shocks. The 2022 problem truncates the second phase of the waveform (SCP-T2), resulting in ∼32-J shocks, and is mitigated by downloadable software. The 2023 malfunction truncates the first phase of the waveform, resulting in 0- to 12-J shocks due to a glassed feedthrough problem (GFT-T1) that might be avoided by programming B>AX shock polarity. The purpose of this study was to assess the consequences of GFT-T1 and SCP-T2 shocks in the Food and Drug Administration's Manufacturers and User Facility Device Experience (MAUDE) database and to estimate the incidences of GFT-T1 and SCP-T2. We analyzed MAUDE reports supplemented by Medtronic data; lead failures were excluded. The incidences of SCP-T2 and GFT-T1 were estimated using USA volumes for devices with glassed feedthroughs. One hundred thirty-two devices delivered truncated shocks: 27 (20.5%) were GFT-T1; 103 (78.0%) were SCP-T2; and 2 (1.5%) truncated both phases (BOTH-T1&2). Of 54 ventricular fibrillation (VF) patients, 21 (38.9%) were not defibrillated by truncated shocks: 8 (38.1%) received GFT-T1 shocks, 12 (57.1%) received SCP-T2 shocks, and 1 received a BOTH-T1&2 shock; 2 patients suffered unrelated deaths; 1 was externally rescued; 1 outcome was unknown; the others were defibrillated by subsequent shocks or terminated spontaneously. The majority of patients (79.1%) shocked for ventricular tachycardia (VT) were converted, primarily (94.1%) by SCP-T2 shocks. Estimated incidences of GFT-T1 and SCP-T2 were 0.0078%–0.0088% and 0.1062%–0.1110%. GFT-T1 and SCP-T2 shocks can result in failure to terminate VF/VT, but they may be preventable. Although the incidences of these truncated shocks are very low, heightened surveillance is warranted. [ABSTRACT FROM AUTHOR]

The LifeVest® wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death in at-risk patients who are not candidates for an implantable defibrillator. The safety and efficacy of the WCD may be impacted by inappropriate shocks (IAS). The purpose of this study was to assess the causes and clinical consequences of WCD IAS in survivors of IAS events. The Food and Drug Administration's Manufacturers and User Facility Device Experience database was searched for IAS adverse events (AE) that were reported during 2021 and 2022. A total of 2568 IAS-AE were found (average number of IAS per event: 1.5 ± 1.9; range 1–48). IAS were caused by tachycardias (1255 [48.9%]), motion artifacts (840 [32.7%]), and oversensing (OS) of low-level electrical signals (473 [18.4%]) (P <.001). Tachycardias included atrial fibrillation (AF) (828 [32.2%]), supraventricular tachycardia (SVT) (333 [13.0%]), and nonsustained ventricular tachycardia/fibrillation (NSVT/VF) (87 [3.4%]). Activities responsible for motion-induced IAS included riding a motorcycle, lawnmower, or tractor (n = 128). In 19 patients, IAS induced sustained ventricular tachycardia or ventricular fibrillation that subsequently were terminated by appropriate WCD shocks. Thirty patients fell and suffered physical injuries. Conscious patients (n = 1905) did not use the response buttons to abort shocks (47.9%) or used them improperly (20.2%). IAS resulted in 1190 emergency room visits or hospitalizations, and 17.3% of patients (421/2440) discontinued the WCD after experiencing IAS, especially multiple IAS. The LifeVest WCD may deliver IAS caused by AF, SVT, NSVT/VF, motion artifacts, and oversensing of electrical signals. These shocks may be arrhythmogenic, result in injuries, precipitate WCD discontinuation, and consume medical resources. Improved WCD sensing, rhythm discrimination, and methods to abort IAS are needed. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Leadless intracardiac pacemakers were developed to avoid the complications of transvenous pacing systems. The Medtronic Micra™ transcatheter pacemaker is one such system. We found an unexpected number of major adverse clinical events (MACE) in the Food and Drug Administration's Manufacturers and User Facility Device Experience (MAUDE) database associated with Micra implantation.Objective: The purpose of this study was to describe these MACE and compare them to implant procedure MACE in MAUDE for Medtronic CapSureFix™ active-fixation transvenous pacing leads.Methods: During January 2021, we queried the MAUDE database for reports of MACE for Micra pacemakers and CapSureFix leads using the simple search terms "death," "tamponade," and "perforation." Reports from 2016-2020 were included.Results: The search identified 363 MACE for Micra and 960 MACE for CapSureFix leads, including 96 Micra deaths (26.4%) vs 23 CapSureFix deaths (2.4%) (P <.001); 287 Micra tamponades (79.1%) vs 225 tamponades for CapSureFix (23.4%) (P <.001); and 99 rescue thoracotomies for Micra (27.3%) vs 50 rescue thoracotomies for CapSureFix (5.2%) (P <.001). More Micra patients required cardiopulmonary resuscitation (21.8% vs 1.1%) and suffered hypotension or shock (22.0% vs 5.8%) than CapSureFix recipients (P <.001). Micra patients were more likely to survive a myocardial perforation or tear if they had surgical repair (P = .014).Conclusion: Micra leadless pacemaker implantation may be complicated by myocardial and vascular perforations and tears that result in cardiac tamponade and death. We estimate the incidence is low (<1%). Rescue surgery to repair perforations may be lifesaving. MACE are significantly less for implantation of CapSureFix transvenous ventricular pacing leads. [ABSTRACT FROM AUTHOR]

New-onset left bundle branch block (N-LBBB) after transcatheter aortic valve replacement (TAVR) is a challenging clinical dilemma. In our single-center study, 60 out of 172 patients who underwent permanent pacemaker implantation (PPM) after TAVR had N-LBBB (34.9%). At a median follow-up duration of 357 days (IQR, 178; 560 days), two patients (3.5%) were completely pacemaker-dependent, and four others (7%) were partially dependent. Twelve patients (24%) recovered conduction in their left bundle at a median follow-up duration of 5 weeks (IQR, 4; 14 weeks). Due to the lack of clinical predictors of pacemaker dependency, active surveillance is warranted and may be an alternative to permanent pacemaker implantation. [ABSTRACT FROM AUTHOR]

Background: Internal insulation breaches (IBR) may result in implantable cardioverter-defibrillator lead failure and adverse clinical events. Concerns exist that the Durata lead may be prone to IBR.Objective: The goals of this study were to assess Durata failures in the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database and compare them to failures in MAUDE for Endotak Reliance and Sprint Quattro Secure (QS) leads.Methods: We searched the MAUDE database from 2008 to 2018 for IBR and other failure modes. Included were explanted leads whose manufacturers found an insulation or conductor defect not caused by extrinsic factors.Results: The MAUDE search found 1011 qualifying leads. The cause of failure differed among leads (P < .001). The primary cause of Durata failure was IBR (293 of 316 leads [93%]), with IBR accounting for 47% (137 of 293); few QS (9 of 523 [1.7%]) and no Endotak Reliance leads failed because of IBR (P < .001). Durata IBR were responsible for 11 failures to treat ventricular tachycardia/ventricular fibrillation, and all were caused by high-voltage (HV) shorts between the proximal superior vena cava coil and a distal right ventricular coil cable (n = 10) or sensing conductor (n = 1); low values of HV impedance were found in these leads during defibrillation threshold testing (n = 3), after a shock or aborted shock (n = 7), and by an alert (n = 1). Inappropriate therapy was caused by 51 Durata IBR, but no QS IBR.Conclusion: Durata implantable cardioverter-defibrillator leads are susceptible to IBR that may result in failure to treat ventricular tachycardia/ventricular fibrillation or inappropriate therapy; such failures may occur without forewarning. HV testing of Durata leads may be indicated during pulse generator replacement or when an insulation defect is suspected. [ABSTRACT FROM AUTHOR]

Background: Studies have shown mortality benefit for implantable cardioverter-defibrillators (ICDs) in ST-elevation myocardial infarction (STEMI) patients with reduced left ventricular ejection fraction (LVEF), but contemporary eligibility and appropriate utilization of ICDs is unknown.Objective: The purpose of this study was to determine the contemporary eligibility and appropriate utilization of ICDs post-STEMI.Methods: Using the prospective Minneapolis Heart Institute regional STEMI registry, LVEF before discharge and at follow-up were stratified into 3 groups: normal (LVEF ≥50%), mildly reduced (LVEF 35%-49%), and severely reduced (LVEF <35%).Results: From March 2003 to June 2012, 3626 patients were treated. Patients with in-hospital death (n = 187), ICD in place (n = 21), negative cardiac biomarkers (n = 337), and undocumented in-hospital LVEF (n = 9) were excluded, leaving 3072 patients in the final analysis, including 1833 (59.7%) with LVEF ≥50%, 875 (28.5%) with LVEF between 35% and 49%, and 364 (11.8%) with LVEF <35% before hospital discharge. Overall, 1029 patients (33.5%) underwent follow-up echocardiography ≥40 days post-STEMI, including 140 of the 364 patients (38.5%) discharged with LVEF <35%. In total, 73 patients (7.1%) with follow-up echocardiography ≥40 days post-STEMI met criteria for an ICD (68 LVEF ≤30%, 5 LVEF 30%-35%, and New York Heart Association class II or greater). Only 26 of these patients (35.6%) underwent ICD placement within 1 year post-STEMI. Overall, only 10% to 15% of potentially eligible patients had an ICD implemented.Conclusion: Rates of ICD implantation in appropriate STEMI patients after 40 days are low. Strategies are needed to identify and expand access to these high-risk patients. [ABSTRACT FROM AUTHOR]

Background: A significant proportion of implantable cardioverter-defibrillators (ICDs) have been subject to Food and Drug Administration (FDA) advisories. The impact of device advisories on mortality or patient care is poorly understood. Although estimated risks of ICD generators under advisory are low, dependency on ICD therapies to prevent sudden death justifies the assessment of long-term mortality. Objective: To test the association of FDA advisory status with long-term mortality. Methods: The study was a retrospective, single-center review of clinical outcomes, including device malfunctions, in patients from implantation to either explant or death. Patients with ICDs first implanted at Cleveland Clinic between August 1996 and May 2004 who became subject to FDA advisories on ICD generators were identified. Mortality was determined by using the Social Security Death Index. Results: In 1644 consecutive patients receiving first ICD implants, 704 (43%) became subject to an FDA advisory, of which 172 (10.5%) were class I and 532 (32.3%) were class II. ICDs were explanted before advisory notifications in 14.0% of class I and 10.1% of class II advisories. Among ICDs under advisory, 28 (4.0%) advisory-related and 15 non–advisory- related malfunctions were documented. Over a median follow-up of 70 months, 814 patients died. Kaplan-Meier 5-year survival rate was 65.6% overall, and 64.2, 61.1, and 69.3% in patients with no, class I, and class II advisories, respectively (P = .17). Conclusions: ICD advisories impacted 43% of the patients. Advisory-related malfunctions affected 4% within the combined advisory group. Based on a conservative management strategy, ICDs under advisory were not associated with increased mortality over a background of significant disease-related mortality. [Copyright &y& Elsevier]

Background: The impact of new-onset persistent left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR) on all-cause mortality has been controversial.Methods: We conducted a systematic review and meta-analysis of eleven studies (7398 patients) comparing the short- and long- outcomes in patients who had new-onset LBBB after TAVR vs. those who did not.Results: During a mean follow-up of 20.5±14months, patients who had new-onset persistent LBBB after TAVR had a higher incidence of all-cause mortality (29.7% vs. 23.6%; OR 1.28 (1.04-1.58), p=0.02), rehospitalization for heart failure (HF) (19.5% vs. 17.3%; OR 1.4 (1.13-1.73), p=0.002), and permanent pacemaker implantation (PPMi) (19.7% vs. 7.1%; OR 2.4 (1.64-3.52), p<0.001) compared with those who did not. Five studies (4180 patients) reported adjusted hazard ratios (HR) for all-cause mortality; new LBBB remained associated with a higher risk of mortality (adjusted HR 1.43 (1.08-1.9), p<0.01, I2=81%).Conclusion: Post-TAVR persistent LBBB is associated with higher PPMi, HF hospitalizations, and all-cause mortality. While efforts to identify patients who need post-procedural PPMi are warranted, more studies are required to evaluate the best follow-up and treatment strategies, including the type of pacing device if required, to improve long-term outcomes in these patients. [ABSTRACT FROM AUTHOR]