Outcomes of leadless pacemaker implantation after cardiac surgery and transcatheter structural valve interventions.

INTRODUCTION: Permanent pacing indications are common after cardiac surgery and transcatheter structural valve interventions. Leadless pacemakers (LPs) have emerged as a useful alternative to transvenous pacemakers. However, current commercially available LPs are unable to provide atrial pacing or cardiac resynchronization and relatively little is known about LP outcomes after cardiac surgery and transcatheter valve interventions. METHODS: This retrospective study included patients who received a Micra VR (MicraTM MC1VR01) or Micra AV (MicraTM MC1AVR1) (Medtronic) leadless pacemaker following cardiac surgery or transcatheter structural valve intervention between September 2014 and September 2022. Device performance and clinical outcomes, including ventricular pacing burden, ejection fraction, and need for conversion to transvenous pacing systems, were evaluated during follow-up. RESULTS: A total of 78 patients were included, of whom 40 received a Micra VR LP implant, and 38 received a Micra AV LP implant. The mean age of the cohort was 65.9 ± 17.9 years, and 48.1% were females. The follow-up duration for the entire cohort was 1.3 ± 1.1 years: 1.6 ± 1.3 years for the Micra VR group and 0.8 ± 0.5 years for the Micra AV group. Among the cohort, 50 patients had undergone cardiac surgery and 28 underwent transcatheter structural valve interventions. Device electrical performance was excellent during follow-up, with a small but clinically insignificant increase in ventricular pacing threshold and a slight decrease in pacing impedance. The mean right ventricle pacing (RVP) burden significantly decreased over time in the entire cohort (74.3% ± 37.2% postprocedure vs. 47.7% ± 40.6% at last follow-up, p < .001), and left ventricle ejection fraction (LVEF) showed a modest but significant downward trend during follow-up (55.0% ± 10.6% vs. 51.5% ± 11.2% p < .001). Patients with Micra VR implants had significantly reduced LVEF during follow-up (54.1% ± 11.9% vs. 48.8% ± 11.9%, p = .003), whereas LVEF appeared stable in the Micra AV group during follow-up (56.1% ± 9.0% vs. 54.6% ± 9.7%, p = .06). Six patients (7.7%) required conversion to transvenous pacing systems, four who required cardiac resynchronization for drop in LVEF with high RVP burden and two who required dual-chamber pacemakers for symptomatic sinus node dysfunction. CONCLUSION: Leadless pacemakers provide a useful alternative to transvenous pacemakers in appropriately selected patients after cardiac surgery and transcatheter structural valve interventions. Device performance is excellent over medium-term follow-up. However, a significant minority of patients require conversion to transvenous pacing systems for cardiac resynchronization or atrial pacing support, demonstrating the need for close electrophysiologic follow-up in this cohort.

Prospective validation of a risk score to predict pacemaker implantation after transcatheter aortic valve replacement.

INTRODUCTION: The need for pacemaker is a common complication after transcatheter aortic valve replacement (TAVR). We previously described the Emory Risk Score (ERS) to predict the need for new pacemaker implant (PPM) after TAVR. Metrics included in the score are a history of syncope, pre-existing RBBB, QRS duration ≥140 ms, and prosthesis oversizing ≥16%. To prospectively validate the previously described risk score. METHODS: We prospectively evaluated all patients without pre-existing pacemakers, ICD, or pre-existing indications for pacing undergoing TAVR with the Edwards SAPIEN 3 prosthesis at our institution from March 2019 to December 2020 (n = 661). Patients were scored prospectively; however, results were blinded from clinical decision-making. The primary endpoint was PPM at 30 days after TAVR. Performance of the ERS was evaluated using logistic regression, a calibration curve to prior performance, and receiver operating characteristic (ROC) analysis. RESULTS: A total of 48 patients (7.3%) had PPM after TAVR. A higher ERS predicted an increased likelihood of PPM (OR 2.61, 95% CI: 2.05-3.25 per point, p < 0.001). There was good correlation between observed and expected values on the calibration curve (slope = 1.04, calibration at large = 0.001). The area under the ROC curve was 0.81 (95% CI [0.74-0.88], p < 0.001). CONCLUSIONS: The ERS prospectively predicted the need for PPM in a serial, real-world cohort of patients undergoing TAVR with a balloon-expandable prosthesis, confirming findings previously described in retrospective cohorts. Notably, the prospective performance of the score was comparable with that of the initial cohorts. The risk score could serve as a framework for preprocedural risk stratification for PPM after TAVR.

Long-term performance of single-connector (DF4) implantable defibrillator leads.

AIMS: Single-connector (DF4) defibrillator leads have become the predominantly implanted transvenous implantable cardioverter-defibrillator lead. However, data on their long-term performance are derived predominantly from manufacturer product performance reports. METHODS AND RESULTS: We reviewed medical records in 5289 patients with DF4 leads between 2011 and 2023 to determine the frequency of lead-related abnormalities. We defined malfunction as any single or combination of electrical abnormalities requiring revision including a sudden increase (≥2×) in stimulation threshold, a discrete jump in high-voltage impedance, or sensing of non-physiologic intervals or noise. We documented time to failure, predictors of failure, and management strategies. Mean follow-up after implant was 4.15 ± 3.6 years (median = 3.63), with 37% of leads followed for >5 years. A total of 80 (1.5%) leads demonstrated electrical abnormalities requiring revision with an average time to failure of 4 ± 2.8 years (median = 3.5). Of the leads that malfunctioned, 62/80 (78%) were extracted and replaced with a new lead and in the other 18 cases, malfunctioned DF4 leads were abandoned, and a new lead implanted. In multivariable models, younger age at implant (OR 1.03 per year; P < 0.001) and the presence of Abbott/St. Jude leads increased the risk of malfunction. CONCLUSION: DF4 defibrillator leads demonstrate excellent longevity with >98.3% of leads followed for at least 5 years still functioning normally. Younger age at implant and lead manufacturer are associated with an increased risk of DF4 lead malfunction. The differences in lead survival between manufacturers require further investigation.

Subdural open drains as an effective and low-cost modality for the treatment of chronic subdural hematomas.

PURPOSE: We present a series that describes the presenting features and clinical outcomes in patients with CSDH treated with a standardised technique and an open-drain placement. METHODS: We reviewed the medical records of 155 consecutive patients at a single centre who underwent CSDH evacuation by placing burr holes, accompanied by intraoperative irrigation and a subdural Penrose drain between 2014 and 2018. RESULTS: The mean age was 65.9 years, 81.9% were males. The most common clinical characteristics were an altered mental state (21.9%) and headache (12.9%). It was necessary to perform a second surgical intervention due to the evidence in the postoperative tomography of a residual hematoma in 10.3% of the cases; there were 2 cases of recurrence in 6 months (1.3%). Pneumonia (6.5%) and seizures (5.8%) were the most frequent medical complications. Intracranial infections accounted for 1.9%, and the mortality rate was 6.4% of cases. CONCLUSIONS: We provided our experience with a low-cost and less-commonly used technique in the management of CSDH. This technique showed similar recurrence, mortality and intracranial infection rates to those reported in the literature for closed drainage systems. Additional studies will be required to assess this technique.

3D-Printed Endoport vs. Open Surgery for Evacuation of Deep Intracerebral Hemorrhage.

BACKGROUND: Large-sized clinical trials have failed to show an overall benefit of surgery over medical treatment in managing spontaneous intracerebral hemorrhages (ICH); less invasive techniques have shown to decrease brain injury caused by surgical manipulation in the standard open approach improving the clinical outcomes of patients. Thereby, we propose a low-cost 3D-printed endoport for a less invasive ICH evacuation. In this study, the authors compare the clinical outcomes of early surgical evacuation using a 3D-printed endoport vs. a standard open surgery (OS). METHODS: A retrospective analysis was conducted comparing patients who underwent early evacuation of a deep hypertensive ICH through an endoport vs. OS at a single center from August 2017 to March 2019. Demographic, clinical, and radiologic data were reviewed. The primary outcomes were the 90-day post-stroke functional outcome and mortality. RESULTS: A total of 36 patients were included. The two cohorts (18 endoport; 18 OS) showed no statistically significant differences in demographic, clinical, and radiologic characteristics, including median admission hemorrhage volume, Glasgow Coma Scale, and ICH scores. At 90-day post-stroke, 44% of patients in the endoport group and 17% in the OS group had a favorable functional outcome (mRS 0-3) (p = 0.039); moreover, the endoport group showed lower mortality (33% vs. 72%, p = 0.019). CONCLUSIONS: This study suggests that an endoport-assisted ICH evacuation may have better functional outcomes and lower mortality than OS. The proposed device could provide a safe, low-cost alternative for ICH's surgical treatment. More rigorous research is hence needed to assess the potential benefits of this technique.

Life cycle management of Micra transcatheter pacing system: Data from a high-volume center.

BACKGROUND: Data on the management of Micra transcatheter pacing system (TPS) at the time of an upgrade or during battery depletion is limited. OBJECTIVE: We sought to evaluate the management patterns of patients implanted with a Micra TPS during long-term follow-up. METHODS: We retrospectively identified patients who underwent Micra implantation from April 2014 to November 2019. We identified patients who underwent extraction (n = 11) or had an abandoned Micra (n = 12). RESULTS: We identified 302 patients who received a Micra during the period of the study. Mean age was 72.7 ± 15.4 years, 54.6% were men, and left ventricular ejection fraction was 51.9 ± 5.2%. Mean follow-up was 1105.5 ± 529.3 days. Procedural complications included pericardial tamponade (n = 1) treated with pericardiocentesis, significant rise in thresholds (n = 6) treated with reimplantation (n = 4), and major groin complications (n = 2). Indications for extraction included an upgrade to cardiac resynchronization therapy (CRT) device (n = 3), bridging after extraction of an infected transvenous system (n = 3), elevated thresholds (n = 3), and non-Micra-related bacteremia (n = 2). The median time from implantation to extraction was 78 days (interquartile range: 14-113 days), with the longest extraction occurring at 1442 days. All extractions were successful, with no procedural or long-term complications. Indications for abandonment included the need for CRT (n = 6), battery depletion (n = 2), increasing thresholds/failure to capture (n = 3), and pacemaker syndrome (n = 1). All procedures were successful, with no procedural or long-term complications. CONCLUSION: In this large single-center study, 6% of patients implanted with a Micra required a system modification during long-term follow-up, most commonly due to the requirement for CRT pacing. These patients were managed successfully with extraction or abandonment.

Characteristics of Pediatric Stroke and Association of Delayed Diagnosis with Mortality in a Mexican Tertiary Care Hospital.

BACKGROUND AND OBJECTIVES: Pediatric cerebrovascular disease carries significant morbidity and mortality. Early recognition of a pediatric stroke as well and its most common risk factors are important, but that diagnosis is often delayed. It is believed that the incidence in our center is higher than it appears. This study aims to assess the incidence and characteristics of the pediatric stroke in our university hospital. Likewise, this study seeks to evaluate if a longer symptoms-to-diagnosis time is associated with mortality in patients with ischemic stroke. METHODS: A retrospective study including children with stroke admitted to the UANL University Hospital from January 2013 to December 2016. RESULTS: A total of 41 patients and 46 stroke episodes were admitted. About 45.7% had an ischemic stroke and 54.3% had a hemorrhagic stroke. A mortality of 24.4% and a morbidity of 60.9% were recorded. Regarding ischemic and hemorrhagic stroke, an increased symptoms-to-diagnosis time and a higher mortality were obtained with a relative risk of 2.667 (95% confidence interval [CI]: 1.09-6.524, p = 0.013) and 8.0 (95% CI: 2.18-29.24, p = < 0.0001), respectively. A continuous increase in the incidence rate, ranging from 4.57 to 13.21 per 1,000 admissions comparing the first period (2013) versus the last period (2016), p = 0.02, was found in our center. CONCLUSIONS: Pediatric stroke is a rare disease; however, its incidence shows a continuous increase. More awareness toward pediatric stroke is needed.

Crossed anterior cerebral circulation in the anterior communicating artery complex, first case report with angiographic evidence.

INTRODUCTION: This case report illustrates a new variant in the anterior cerebral artery complex, identified during carotid angioplasty. CLINICAL CASE: A 50-year-old male patient diagnosed with left carotid stenosis was diagnosed and treated by a cerebral angiography. During the procedure, crossed circulation in the anterior cerebral artery was identified. The presence of this variation demanded to discard distal emboli or artery dissection. Angioplasty was performed and the patient followed up without neurological deficit. DISCUSSION: Among the most possible and prevalent variations in anterior circulation, none of them explain the phenomenon we observed. Therefore, a new variant is established. The knowledge about variants in cerebral circulation is important to rule out pathology. CONCLUSION: Cerebral diagnostic angiography has become more available and frequent because of the rising in endovascular tools to treat stroke patients. Considering this new variation and others is important to discard pathology.

Backtesting VaR under the COVID-19 sudden changes in volatility.

We analyze the impact of the COVID-19 pandemic on the conditional variance of stock returns. We look at this effect from a global perspective, so we employ series of major stock market and sector indices. We use the Hansen's Skewed-t distribution with EGARCH extended to control for sudden changes in volatility. We oversee the COVID-19 effect on measures of downside risk such as the Value-at-Risk. Our results show that there is a significant sudden shift up in the return distribution variance post the announcement of the pandemic, which must be explained properly to obtain reliable measures for financial risk management.

Sex-based differences in procedural complications associated with atrial fibrillation catheter ablation: A systematic review and meta-analysis.

BACKGROUND: Women undergoing atrial fibrillation catheter ablation (AFCA) have higher rates of vascular complications and major bleeding. However, most studies have been underpowered to detect differences in rarer complications such as stroke/transient ischemic attack (TIA) and procedural mortality. METHODS: We performed a systematic review of databases (PubMed, World of Science, and Embase) to identify studies published since 2010 reporting AFCA complications by sex. Six complications of interest were (1) vascular/groin complications; (2) pericardial effusion/tamponade; (3) stroke/TIA; (4) permanent phrenic nerve injury; (5) major bleeding; and (6) procedural mortality. For meta-analysis, random effects models were used when heterogeneity between studies was ≥50% (vascular complications and major bleeding) and fixed effects models for other endpoints. RESULTS: Of 5716 citations, 19 studies met inclusion criteria, comprising 244,353 patients undergoing AFCA, of whom 33% were women. Women were older (65.3 ± 11.2 vs. 60.4 ± 13.2 years), more likely hypertensive (60.6% vs. 55.5%) and diabetic (18.3% vs. 16.5%), and had higher CHA2 DS2 -VASc scores (3.0 ± 1.8 vs. 1.4 ± 1.4) (p < .0001 for all comparisons). The rates of all six complications were significantly higher in women. However, despite statistically significant differences, the overall incidences of major complications were very low in both sexes: stroke/TIA (women 0.51% vs. men 0.39%) and procedural mortality (women 0.25% vs. men 0.19%). CONCLUSION: Women experience significantly higher rates of AFCA complications. However, the incidence of major procedural complications is very low in both sexes. The higher rate of complications in women may be partially attributable to older age and a higher prevalence of comorbidities at the time of ablation. More detailed studies are needed to better define the mechanisms of increased risk in women and to identify strategies for closing the sex gap.

Cardiac implantable electronic devices in patients with persistent left superior vena cava-A single center experience.

BACKGROUND: There are limited data on cardiac implantable electronic device implantation (CIED) in patients with persistent left superior vena cava (PLSVC). OBJECTIVE: To describe the outcomes of implanting CIEDs with a focus on cardiac resynchronization therapy (CRT) in patients with PLSVC. METHODS: We identified all patients with a PLSVC that underwent CIED implantation from December 2008 until February 2019 at our institution by querying the electronic medical record (n = 34). We then identified controls in a 3:1 fashion (n = 102) by matching on device type (CRT vs non-CRT). Procedure success, complications, fluoroscopy and procedural time were recorded. Outcomes were compared using a two-way analysis of variance test and conditional regression modeling for continuous and categorical variables, respectively. RESULTS: A total of 34 patients with PLSVC underwent 38 procedures. Four patients underwent dual chamber system implantation followed by a subsequent upgrade to CRT. Thirteen patients underwent CRT implantation: one was implanted via the right subclavian while the rest were implanted via the PLSVC. Left ventricular (P = .06). Procedure and fluoroscopy times were significantly higher in the PLSVC as compared with the control group (97.7 vs 66.1 minute, P < .001 and 18.1 minute vs 8.7 minutes, P = .005, respectively). CONCLUSION: CIED implant in patients with PLSVC is feasible but technically more challenging and appears to be associated with higher risk of right ventricular lead dislodgment.

Outcomes of convergent atrial fibrillation ablation with continuous rhythm monitoring.

BACKGROUND: Outcomes of catheter ablation for persistent atrial fibrillation (PeAF) are suboptimal. The convergent procedure (CP) may offer improved efficacy by combining endocardial and epicardial ablation. METHODS: We reviewed 113 consecutive patients undergoing the CP at our institution. The cohort was divided into two groups based on the presence (n = 92) or absence (n = 21) of continuous rhythm monitoring (CM) following the CP. Outcomes were reported in two ways. First, using a conventional definition of any atrial fibrillation/atrial tachycardia (AF/AT) recurrence lasting >30 seconds, after a 90 day blanking period. Second, by determining AF/AT burden at relevant time points in the group with CM. RESULTS: Across the entire cohort, 88% had either persistent or long-standing persistent AF, mean duration of AF diagnosis before the CP was 5.1 ± 4.6 years, 45% had undergone at least one prior AF ablation, 31% had impaired left ventricle ejection fraction and 62% met criteria for moderate or severe left atrial enlargement. Mean duration of follow-up after the CP was 501 ± 355 days. In the entire cohort, survival free from any AF/AT episode >30 seconds at 12 months after the blanking period was 53%. However, among those in the CM group who experienced recurrences, mean burden of AF/AT was generally very low (<5%) and remained stable over the duration of follow-up. Ten patients (9%) required elective cardioversion outside the 90 day blanking period, 11 patients (9.7%) underwent repeat ablation at a mean of 229 ± 178 days post-CP and 64% were off AADs at the last follow-up. Procedural complications decreased significantly following the transition from transdiaphragmatic to sub-xiphoid surgical access: 23% versus 3.8% (P = .005) CONCLUSIONS: In a large, consecutive series of patients with predominantly PeAF, the CP was capable of reducing AF burden to very low levels (generally <5%), which appeared durable over time. Complication rates associated with the CP decreased significantly with the transition from transdiaphragmatic to sub-xiphoid surgical access. Future trials will be necessary to determine which patients are most likely to benefit from the convergent approach.

Outcomes of Micra leadless pacemaker implantation with uninterrupted anticoagulation.

BACKGROUND: Implantation of the MICRA Leadless pacemaker requires the use of a 27 French introducer, blunt delivery system and device fixation to the myocardium via nitinol tines. While prior studies have proven its safety, it is unclear whether performing this procedure with uninterrupted anticoagulation exposes patients to increased risks. We sought to investigate the feasibility and safety of continuing therapeutic anticoagulation during the periprocedural period. METHODS: We evaluated all patients undergoing MICRA placement at our institution between April 2014 and August 2018 with complete follow-up data (n = 170). Patients were stratified into two groups: those on active anticoagulation (OAC, n = 26), defined as having an International normalized ratio >2.0 or having continued a direct oral anticoagulant, and those not anticoagulated (Off-OAC, n = 144). We evaluated for a composite outcome of all major complications, including access site complications and pericardial effusion. RESULTS: OAC and Off-OAC groups had similar mean age (74 ± 13 vs 75 ± 13 years; P = .914). The OAC group had a nonsignificantly lower prevalence of end-stage renal disease (8% vs 17%; P = .375) and aspirin use (27% vs 47%; P = .131). Those in the OAC group were more likely to be on warfarin than those in the Off-OAC group (81% vs 30%; P < .001). The rate of the composite endpoint was similar between the OAC and Off-OAC groups (3.8 % vs 1.4%, respectively; P = .761). Length of stay was similar between groups (1.3 ± 2.6 vs 2.3 ± 3.4 days; P = 0.108). CONCLUSION: Continuation of therapeutic anticoagulation during MICRA implantation appears to be feasible, safe and associated with shorter hospitalization among appropriately selected individuals.

Effect of defibrillation threshold testing on effectiveness of the subcutaneous implantable cardioverter defibrillator.

BACKGROUND: Defibrillation threshold (DFT) testing is recommended with the subcutaneous implantable cardioverter defibrillator (SICD). OBJECTIVE: To describe first shock efficacy for appropriate SICD therapies stratified by the presence of implant DFT testing. METHODS: We reviewed all patients receiving SICDs at our institution and stratified them based on whether implant DFT testing was performed. Appropriate shocks were reviewed to see if ventricular tachycardia/ventricular fibrillation (VT/VF) terminated with a single shock. First shock efficacy was stratified by implant DFT status. RESULTS: 178 patients implanted with SICDs and followed in our center were included in this study. Of these, 135 (76%) underwent DFT testing (DFT (+) group). In the DFT (+), 80 appropriate shocks were needed to treat 69 episodes of VT/VF. The first shock was effective in 61 out of 69 episodes (88.4%), whereas multiple shocks were required to terminate VT/VF in the remaining eight episodes. Among 43 patients without implant DFT testing (DFT (-) group), 20 appropriate shocks to treat 17 episodes of VT/VF occurred in seven patients. VT/VF was successfully terminated with the first shock in 16 out of 17 episodes (first shock efficacy 94.1 %). There was no significant difference in first shock effectiveness between those with and without implant DFT testing (P  =  0.97). CONCLUSION: A strategy that omits DFT testing at implant did not appear to compromise the effectiveness of the SICD. These data suggest that routine DFT testing at SICD implant might not be necessary. Randomized trials are needed to confirm this finding.

Procedural outcomes and long-term survival following trans-venous defibrillator lead extraction in patients with end-stage renal disease.

AIMS: End-stage renal disease (ESRD) increases the risk of implantable cardioverter-defibrillator (ICD) infection. We sought to define outcomes of lead extraction in patients with ESRD. METHODS AND RESULTS: Implantable cardioverter-defibrillator lead extractions at our institution from January 2006 to March 2014 were stratified by absence (Control-Ex, n = 465) or presence (ESRD-Ex, n = 43) of ESRD. Procedural outcomes and survival were determined by medical records review. Survival in the ESRD-Ex group was compared with a contemporaneous cohort with ESRD undergoing ICD lead implantation (ESRD-I, n = 127). Among extraction patients, those with ESRD were more likely to be extracted for infection (74.4% vs. 28.6%, P < 0.001). Extraction procedure success (Control-Ex: 97% vs. ESRD-Ex: 93%, P = 0.17) and procedural deaths (Control-Ex: 1.1% vs. ESRD-Ex: 2.3%, P = 0.413) were similar. Survival 1 year following extraction was worse in the ESRD-Ex group compared with the Control-Ex, with a survival rate of 65.6% vs. 92.6% (P < 0.001); these curves continued to diverge through year 3. One-year survival in the ESRD-Ex group was worse than among ESRD patients undergoing ICD implant (ESRD-I), but these curves converged and survival was similar by year 3. CONCLUSIONS: Implantable cardioverter-defibrillator lead extraction can be performed safely and effectively in patients with ESRD. However, despite high rates of procedural success, long-term mortality following extraction in ESRD patients is substantial. Much of the long-term mortality risk appears to be accounted for by the presence of ESRD and an indication for an ICD.

Procedural outcomes and long-term survival following lead extraction in octogenarians.

BACKGROUND: Octogenarians account for a significant percentage of patients with indwelling pacemakers or defibrillators. OBJECTIVES: To determine procedural outcomes and long-term survival after lead extraction (LE) in octogenarians. METHODS: We retrospectively identified all patients who underwent defibrillator or pacemaker LE at our institution between January 1, 2007 and May 31, 2016. Patients were stratified based on age into two groups: <80 years old (Group 1, n = 674) or ≥80 (Group 2, n = 100). Outcomes were determined by medical records review and query of the Social Security Death Index. RESULTS: Patients in Group 2 were more likely to be hypertensive (77% vs 61%, P = 0.02), more like to have coronary artery disease (50% vs 39%, P = 0.049), and more likely to be extracted for infectious indications (47% vs 33%, P = .009). The number of leads extracted per procedure was 2.0 ± 0.8 and the mean dwell time of the oldest extracted lead was 5.6 ± 4.3 years, without significant differences between groups. Extraction procedure success (Group 1: 94.7%, Group 2: 96%, P = 0.808) and procedural deaths (Group 1: 0.9% vs Group 2: 0%, P = 1.0) were similar. There was no significant difference in survival up to 3 years following LE between groups. CONCLUSION: At experienced centers, LE can be performed safely in octogenarians with procedural success rates and long-term survival comparable to younger individuals.

Clinical Performance of Magnetic Resonance Imaging Conditional and Nonconditional Cardiac Implantable Electronic Devices.

OBJECTIVES: This study compared risks associated with magnetic resonance imaging (MRI) in patients with non-MRI conditional and MRI conditional pacing and defibrillator systems with particular attention to clinically actionable outcomes. BACKGROUND: While recipients of new MRI conditional pacemaker and defibrillator systems may undergo MRI scanning with very low risk, safety and regulatory concerns persist regarding such scanning in recipients of non-MRI conditional systems. METHODS: Patients with any cardiac device who were referred for MRI were prospectively enrolled at a single center and underwent scanning at 1.5 Tesla. Pre- and postscan lead characteristic changes, system integrity, and symptoms were analyzed. A comparison was made between non-MRI conditional and MRI conditional devices. RESULTS: 105 patients were evaluated allowing for comparison of 97 scans with non-MRI conditional devices and 16 scans with MRI conditional devices. The cohort included those with pacemaker dependency, defibrillator, and cardiac resynchronization devices. Small, nonsignificant changes were observed in lead characteristics following scanning, and there was no significant difference when comparing non-MRI and MRI conditional devices. Lead parameter changes did not require lead revision or programming changes. No device reset, failures, or premature scan termination was observed. CONCLUSIONS: 1.5 T MRI scanning in patients with MRI conditional and non-MRI conditional cardiac devices was performed with similar, low clinical risk.

Peri-infarct zone pacing to prevent adverse left ventricular remodelling in patients with large myocardial infarction.

AIMS: We sought to determine whether peri-infarct pacing prevents left ventricular (LV) remodelling and improves functional and clinical outcomes in patients with large first myocardial infarction (MI). METHODS AND RESULTS: A total of 126 patients at 27 international sites within 10 days of onset of anterior or non-anterior MI with creatine phosphokinase >3000 U/L and QRS duration ≤120 ms were randomized 1:1:1 to dual-site biventricular pacing vs. single-site LV only pacing vs. non-implanted control. The primary endpoint was the echocardiographic core laboratory-assessed change in LV end-diastolic volume (ΔLVEDV) from baseline to 18 months between the pooled pacing therapy groups and the control group. ΔLVEDV increased by 15.3 ± 28.6 mL in the control group and by 16.7 ± 30.5 mL in the pooled pacing groups during follow-up (adjusted mean difference (95% CI) = 0.6 (-12.3, 13.5) mL, P = 0.92). There were also no significant between-group differences in the change in LV end-systolic volume or ejection fraction over time. Quality of life, as assessed by the Minnesota Living with Heart Failure (HF) and European Quality of Life-5 Dimension questionnaires and New York Heart Association class, was also similar between groups during 18-month follow-up. Six-minute walk distance improved during follow-up to an equal degree between groups, and there were no significant differences in the 18-month rates of death or HF hospitalization between the pooled pacing therapy vs. control groups (17.4 vs. 21.7% respectively, P = 0.59). CONCLUSIONS: In the present multicentre, randomized trial, peri-infarct pacing did not prevent LV remodelling or improve functional or clinical outcomes during 18-month follow-up in patients with large first MI. CLINICALTRIALSGOV IDENTIFIER: NCT01213251.

The learning curve associated with the introduction of the subcutaneous implantable defibrillator.

AIMS: The subcutaneous implantable cardioverter defibrillator (S-ICD) was introduced to overcome complications related to transvenous leads. Adoption of the S-ICD requires implanters to learn a new implantation technique. The aim of this study was to assess the learning curve for S-ICD implanters with respect to implant-related complications, procedure time, and inappropriate shocks (IASs). METHODS AND RESULTS: In a pooled cohort from two clinical S-ICD databases, the IDE Trial and the EFFORTLESS Registry, complications, IASs at 180 days follow-up and implant procedure duration were assessed. Patients were grouped in quartiles based on experience of the implanter and Kaplan-Meier estimates of complication and IAS rates were calculated. A total of 882 patients implanted in 61 centres by 107 implanters with a median of 4 implants (IQR 1,8) were analysed. There were a total of 59 patients with complications and 48 patients with IAS. The complication rate decreased significantly from 9.8% in Quartile 1 (least experience) to 5.4% in Quartile 4 (most experience) (P = 0.02) and non-significantly for IAS from 7.9 to 4.8% (P = 0.10). Multivariable analysis demonstrated a hazard ratio of 0.78 (P = 0.045) for complications and 1.01 (P = 0.958) for IAS. Dual-zone programming increased with experience of the individual implanter (P < 0.001), which reduced IAS significantly in the multivariable model (HR 0.44, P = 0.01). Procedure time decreased from 75 to 65 min (P < 0.001). The complication rate and procedure time stabilized after Quartile 2 (>13 implants). CONCLUSION: There is a short and significant learning curve associated with physicians adopting the S-ICD. Performance stabilizes after 13 implants.

Management of New-Onset Postoperative Atrial Fibrillation Utilizing Insertable Cardiac Monitor Technology to Observe Recurrence of AF (MONITOR-AF).

BACKGROUND: New-onset postoperative atrial fibrillation (POAF) occurs in up to 30% of patients undergoing coronary artery bypass grafting (CABG). POAF is associated with short- and long-term mortality. METHODS: To identify the true incidence and time course of recurrent atrial fibrillation (AF) in patients with POAF, we prospectively assigned 23 patients with POAF to receive an implantable loop recorder (ILR; Medtronic Inc., Minneapolis, MN, USA) for the detection of recurrent AF. Two electrophysiologists independently adjudicated monthly ILR transmissions to classify recurrent AF. We defined AF as any episode lasting ≥6 minutes. RESULTS: The cohort included 23 subjects averaging 69.1 ± 7.2 years of age. Their mean CHADS2 score averaged 1.9 ± 0.8. Note that 26.1% underwent direct current cardioversion prior to discharge; 95.7% left the hospital taking amiodarone and 26.1% warfarin. A total of 14 patients (60.9%) experienced recurrent AF. AF first recurred within 3 months in nine patients (39.1%), and in 10 patients AF emerged or continued beyond 3 months. Eight of 17 (47.1%) patients followed for at least 1 year experienced AF recurrence beyond 1 year of CABG. The time from surgery to first AF episode averaged 143 ± 22.5 days. Long-term monitoring shows that 60.9% of patients with POAF develop recurrent AF. CONCLUSION: POAF may represent a propensity for recurrent paroxysmal atrial fibrillation, and not simply a transient consequence of postoperative stress and inflammation. Better detection of recurrent AF might identify patients at risk for stroke who would benefit from continuing anticoagulation.