Clinical and Economic Outcomes Associated With Remote Monitoring for Cardiac Implantable Electronic Devices: A Population-Based Analysis.

BACKGROUND: Despite expert recommendations advocating use of remote monitoring (RM) of cardiac implantable electronic devices, implementation in routine clinical practice remains modest due to inconsistent funding policies across health systems and uncertainty regarding the efficacy of RM to reduce adverse cardiovascular outcomes. METHODS: We conducted a population-based cohort study of patients with de novo implantable cardioverter-defibrillators (ICDs) with or without cardiac resynchronization therapy (CRT-D), using administrative health data in Alberta, Canada, from 2010 to 2016. We assessed RM status as a predictor of all-cause mortality and cardiovascular (CV) hospitalization using Cox proportional hazards modelling, and direct health costs by generalized linear models. From this real-world data, we then constructed a decision-analytic Markov model to estimate the projected costs and benefits associated with RM compared with in-clinic visit follow-up alone. RESULTS: Among 2799 ICD and CRT-D patients, 1830 (63.4%) were followed by RM for a mean follow-up of 50.3 months. After adjustment for age, sex, and comorbidities, RM was associated with a lower risk of death (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.36-0.52; P < 0.001) and CV hospitalization (HR 0.76, 95% CI 0.64-0.91; P = 0.002). In the economic model, cost savings were observed over 5 years with an estimated savings of $12,195 per person (95% CI -$21,818 to -$4,790). The model estimated a cost-savings associated with RM strategy in 99% of simulations. CONCLUSIONS: These population data support more widespread implementation of RM technology to facilitate better patient outcomes and improve health system efficiency.

A Novel High-Resolution Surface Electrocardiographic Method to Identify and Characterize Myocardial Scar: A Proof-of-Concept Study.

BACKGROUND: The placement of the left ventricular (LV) lead in an area free of myocardial scar is an important determinant of cardiac resynchronization therapy response. We sought to develop and validate a simple, practical, and novel electrocardiographic (ECG)-based approach to intraoperatively identify the presence of LV scar. We hypothesized that there would be a reduction in the measured amplitude of the LV pacing stimulus on the skin surface using a high-resolution (HR) ECG when pacing from LV regions with scar compared with regions without scar. We term this the ECG Amplitude Signal Evaluation (EASE) method. METHODS: Consecutive patients with ischemic LV systolic dysfunction and standard criteria for de novo cardiac resynchronization therapy implantation were prospectively enrolled. All underwent a preimplant contrast-enhanced cardiac magnetic resonance study to assess for scar. The average amplitude of the LV pacing impulse was sampled on HR surface ECG intraprocedurally and then compared with the cardiac magnetic resonance results. RESULTS: A total of 38 LV pacing sites were assessed among 13 recipients. The median voltage measured on the surface HR ECG in regions with scar was reduced by 41% (interquartile range, 17% to 63%), whereas there was no measurable change in voltage (interquartile range, 0 to 0%) in regions without scar compared with the maximal amplitude (Wilcoxon P < 0.0001). CONCLUSION: The EASE method appears to be of potential value as a novel intraoperative tool to guide LV lead placement to regions free of scar. Future work is required to validate the utility of this method in a larger patient cohort.

CONTEXTE: La mise en place de la sonde ventriculaire gauche dans une zone exempte de cicatrice myocardique est un facteur déterminant de la réponse au traitement de resynchronisation cardiaque. Nous avons cherché à développer et à valider une approche électrocardiographique (ECG) simple, concrète et novatrice afin de repérer de manière peropératoire la présence de tissu cicatriciel au ventricule gauche (VG). Nous avons émis l'hypothèse qu'il y aurait une diminution de l'amplitude du rythme de stimulation du ventricule gauche mesurée à la surface de la peau à l'ECG haute résolution (HR) lors de la stimulation de régions du VG présentant du tissu cicatriciel comparativement aux régions exemptes de cicatrices. Il s'agit de ce que nous appelons la méthode EASE ( E CG A mplitude S ignal E valuation). MÉTHODOLOGIE: Des patients vus de manière consécutive qui présentaient une dysfonction systolique ischémique du VG et répondaient aux critères standard pour l'implantation de novo d'un dispositif de resynchronisation cardiaque ont été recrutés de manière prospective. Tous ont fait l'objet d'une résonance magnétique cardiaque améliorée par injection d'un produit de contraste avant l'implantation pour évaluer la présence de tissu cicatriciel. L'amplitude moyenne de l'impulsion de stimulation du VG a été échantillonnée sur l'ECG de surface HR réalisé pendant l'intervention, puis comparée aux résultats de la résonance magnétique cardiaque. RÉSULTATS: En tout, 38 points de stimulation du VG ont été évalués chez 13 receveurs. Le voltage médian mesuré sur l'ECG de surface HR dans les régions présentant du tissu cicatriciel était réduit de 41 % (intervalle interquartile : 17 % à 63 %), tandis qu'il n'y avait pas de changement mesurable du voltage (intervalle interquartile : 0 à 0 %) dans les régions exemptes de cicatrices par rapport à l'amplitude maximale (test de Wilcoxon, p < 0,0001). CONCLUSION: La méthode EASE semble avoir une utilité potentielle en tant que nouvel outil peropératoire pour guider la mise en place de la sonde ventriculaire gauche dans les régions exemptes de cicatrices. Il faudra réaliser d'autres travaux pour valider l'utilité de cette méthode dans une cohorte de patients plus importante.

Post-operative pain following cardiac implantable electronic device implantation: insights from the BRUISE CONTROL trials.

AIMS: Post-operative pain following cardiac implantable electronic device (CIED) insertion is associated with patient dissatisfaction, emotional distress, and emergency department visits. We sought to identify factors associated with post-operative pain and develop a prediction score for post-operative pain. METHODS AND RESULTS: All patients from the BRUISE CONTROL-1 and 2 trials were included in this analysis. A validated Visual Analogue Scale (VAS) was used to assess the severity of pain related to CIED implant procedures. Patients were asked to grade the most severe post-operative pain, average post-operative pain, and pain on the day of the first post-operative clinic. Multivariable regression analyses were performed to identify predictors of significant post-operative pain and to develop a pain-prediction score. A total of 1308 patients were included. Multivariable regression analysis found that the presence of post-operative clinically significant haematoma {CSH; P value < 0.001; odds ratio (OR) 3.82 [95% confidence interval (CI): 2.37-6.16]}, de novo CIED implantation [P value < 0.001; OR 1.90 (95% CI: 1.47-2.46)], female sex [P value < 0.001; OR 1.61 (95% CI: 1.22-2.12)], younger age [<65 years; P value < 0.001; OR 1.54 (95% CI: 1.14-2.10)], and lower body mass index [<20 kg/m2; P value < 0.05; OR 2.05 (95% CI: 0.98-4.28)] demonstrated strong and independent associations with increased post-operative pain. An 11-point post-operative pain prediction score was developed using the data. CONCLUSION: Our study has identified multiple predictors of post-operative pain after CIED insertion. We have developed a prediction score for post-operative pain that can be used to identify individuals at risk of experiencing significant post-operative pain.

Effect of Direct Oral Anticoagulants, Warfarin, and Antiplatelet Agents on Risk of Device Pocket Hematoma: Combined Analysis of BRUISE CONTROL 1 and 2.

BACKGROUND: Oral anticoagulant use is common among patients undergoing pacemaker or defibrillator surgery. BRUISE CONTROL (Bridge or Continue Coumadin for Device Surgery Randomized Controlled Trial; NCT00800137) demonstrated that perioperative warfarin continuation reduced clinically significant hematomas (CSH) by 80% compared with heparin bridging (3.5% versus 16%). BRUISE-CONTROL-2 (NCT01675076) observed a similarly low risk of CSH when comparing continued versus interrupted direct oral anticoagulant (2.1% in both groups). Using patient level data from both trials, the current study aims to: (1) evaluate the effect of concomitant antiplatelet therapy on CSH, and (2) understand the relative risk of CSH in patients treated with direct oral anticoagulant versus continued warfarin. METHODS: We analyzed 1343 patients included in BRUISE-CONTROL-1 and BRUISE-CONTROL-2. The primary outcome for both trials was CSH. There were 408 patients identified as having continued either a single or dual antiplatelet agent at the time of device surgery. RESULTS: Antiplatelet use (versus nonuse) was associated with CSH in 9.8% versus 4.3% of patients (P<0.001), and remained a strong independent predictor after multivariable adjustment (odds ratio, 1.965; 95% CI, 1.202-3.213; P=0.0071). In multivariable analysis, adjusting for antiplatelet use, there was no significant difference in CSH observed between direct oral anticoagulant use compared with continued warfarin (odds ratio, 0.858; 95% CI, 0.375-1.963; P=0.717). CONCLUSIONS: Concomitant antiplatelet therapy doubled the risk of CSH during device surgery. No difference in CSH was found between direct oral anticoagulant versus continued warfarin. In anticoagulated patients undergoing elective or semi-urgent device surgery, the patient specific benefit/risk of holding an antiplatelet should be carefully considered. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00800137, NCT01675076.

Continued vs. interrupted direct oral anticoagulants at the time of device surgery, in patients with moderate to high risk of arterial thrombo-embolic events (BRUISE CONTROL-2).

Aims: Guidelines recommend warfarin continuation rather than heparin bridging for pacemaker and defibrillator surgery, after the BRUISE CONTROL trial demonstrated an 80% reduction in device pocket haematoma with this approach. However, direct oral anticoagulants (DOACs) are now used to treat the majority of patients with atrial fibrillation. We sought to understand the best strategy to manage the DOACs at the time of device surgery and specifically hypothesized that performing device surgery without DOAC interruption would result in a reduced haematoma rate. Methods and results: We randomly assigned patients with atrial fibrillation and CHA2DS2-VASc score ≥2, to continued vs. interrupted DOAC (dabigatran, rivaroxaban, or apixaban). The primary outcome was blindly evaluated, clinically significant device pocket haematoma: resulting in re-operation, interruption of anticoagulation, or prolonging hospital stay. In the continued arm, the median time between pre- and post-operative DOAC doses was 12 h; in the interrupted arm the median time was 72 h. Clinically significant haematoma occurred in of 7 of 328 (2.1%; 95% CI 0.9-4.3) patients in the continued DOAC arm and 7 of 334 (2.1%; 95% CI 0.9-4.3) patients in the interrupted DOAC arm (P = 0.97). Complications were uncommon, and included one stroke and one symptomatic pericardial effusion in each arm. Conclusions: These results suggest that, dependent on the clinical scenario, either management strategy (continued DOAC or interrupted DOAC) might be reasonable, at least for patients similar to those enrolled in our trial.

Assessing physician knowledge regarding indications for a primary prevention implantable defibrillator and potential barriers for referral.

BACKGROUND: Although there is clear evidence to demonstrate that primary prevention implantable defibrillators (ICDs) reduce mortality in high-risk patients, ICDs are underutilized. Limited data exist assessing referring physicians' knowledge about guideline indications and attitudes towards ICDs, which may influence decision for referral. METHODS AND RESULTS: The Arrhythmia Working Group from the Alberta Cardiovascular and Stroke Strategic Clinical Network developed a web-based survey consisting of case scenarios regarding primary prevention ICD indications and a list of barriers for referral to aid in the design of a complex device care pathway. We invited referring physicians to participate in the survey including internists and cardiologists and cardiology residents. The survey was completed by 109 of 799 (response rate = 14%) of physicians. Of those, 55% were internists, 32% cardiologists, and 13% cardiology residents. The majority of physicians were male (62%), practicing in a university hospital (66%). Overall, complete guideline-concordant answers were provided by 34% of physicians. In multivariable analysis, predictors of complete guideline concordance were being a cardiologist (odd ratio [OR] 5.9, confidence interval [CI] 2.1-16.4, P = 0.001) and cardiology resident (OR 6.7, CI 1.7-27.3, P = 0.007). The most common barrier for referral for internists was lack of confidence in knowledge of guideline recommendations; while cardiologists reported concerns about cost-effectiveness and cardiology residents were most concerned with inappropriate shocks. CONCLUSION: Knowledge regarding indications for primary prevention ICD is limited and varies significantly among referring physicians. The barriers for referral differ among physician groups and addressing these identified barriers may help to improve appropriate ICD utilization.

Sudden cardiac death.

Sudden death accounts for 300,000-400,000 deaths annually in the United States. Most sudden deaths are cardiac, and most sudden cardiac deaths are related to arrhythmias secondary to structural heart disease or primary electrical abnormalities of the heart. The most common structural disease leading to sudden death is ischemic heart disease. Nonischemic cardiomyopathy and other structural abnormalities such as arrhythmogenic ventricular dysplasia and hypertrophic cardiomyopathy may also be causative. Patients without structural disease have a primary electrical abnormality, such as long-QT syndrome or Brugada syndrome. Severe left ventricular systolic dysfunction is the main marker for sudden death in patients with ischemic or nonischemic cardiomyopathy. In other conditions, other markers for structural heart disease and electrical abnormalities need to be considered. It is seen that ß-blocker therapy is associated with a reduction in sudden cardiac death across a broad range of disorders. Nevertheless, the implantable cardioverter defibrillator remains the most effective treatment strategy in selected patients.

Impact of programming strategies aimed at reducing nonessential implantable cardioverter defibrillator therapies on mortality: a systematic review and meta-analysis.

BACKGROUND: Patients who receive implantable cardioverter defibrillator therapies are at higher risk of death versus those who do not. Programmed settings to reduce nonessential implantable cardioverter defibrillator therapies (therapy reduction programming) have been developed but may have adverse effects. This systematic review and meta-analysis assessed the relationship between therapy reduction programming with the risks of death from any cause, implantable cardioverter defibrillator shocks, and syncope. METHODS AND RESULTS: MEDLINE, EMBASE, and clinicaltrials.gov databases were searched to identify relevant studies. Those that followed patients for ≥6 months and reported mortality were included. Six met the inclusion criteria; 4 randomized (Comparison of Empiric to Physician-Tailored Programming of ICDs [EMPIRIC], Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy [MADIT-RIT], Avoid Delivering Therapies for Non-sustained Arrhythmias in ICD Patients III [ADVANCE III], and Programming Implantable Cardioverter-Defibrillators in Patients with Primary Prevention Indication to Prolong Time to First Shock [PROVIDE]) and 2 prospective studies (Role of Long Detection Window Programming in Patients With Left Ventricular Dysfunction, Non-ischemic Etiology in Primary Prevention Treated with a Biventricular ICD [RELEVANT] and Primary Prevention Parameters Evaluation [PREPARE]). These 6 studies included 7687 (3598 conventional and 4089 therapy reduction programming) patients. Most (77%) participants were men, had a history of ischemic heart disease (56%), and were prescribed ß-blockers (84%). Therapy reduction programming was associated with a 30% relative reduction in mortality (95% confidence interval, 16%-41%; P<0.001). No significant heterogeneity among studies was observed (P=0.6). A similar 26% reduction in mortality was observed when only the 4 randomized trials were included (95% confidence interval, 11%-40%; P=0.002). These results were not significantly altered after adjustment for baseline characteristics. No significant difference in the risk of syncope was observed with conventional versus therapy reduction programming (P=0.5). CONCLUSIONS: Therapy reduction programming results in a large, significant, and consistent reduction in mortality, with no apparent increase in the risk of syncope.

Alternative surgical approach to repair of the ascending aorta.

We describe a case of complete endovascular repair of the ascending aorta using a transfemoral approach. A 59-year-old man with a history of two previous sternotomies experienced an ascending aortic pseudoaneurysm arising from the graft-to-graft anastomosis of a previous DeBakey type I aortic dissection repair. A custom-made Zenith TX2 (William Cook Europe ApS, Bjaeverskov, Denmark) thoracic aortic aneurysm endovascular graft, designed specifically for the ascending aorta, was introduced through the left femoral artery and deployed under a rapid ventricular pacing protocol to achieve precise placement between the sinotubular junction and the aortic arch.

Recent history of vasovagal syncope in a young, referral-based population is a stronger predictor of recurrent syncope than lifetime syncope burden.

INTRODUCTION: accurate selection of patients for vasovagal syncope studies requires strong risk stratification and knowledge of the natural history of syncope. We aimed to test the hypothesis that recent history of vasovagal syncope compared to distant history better predicts subsequent recurrence of syncope. METHODS AND RESULTS: in all, 208 subjects with a positive tilt test and ≥ 3 lifetime syncope spells were followed for 1 year. Syncope episodes in the preceding year and total historical spells were compared for their ability to predict a syncope recurrence using the criteria of optimal statistical significance, best linear separation of risk populations, and impact on power calculations. The number of vasovagal syncope spells in the preceding year better predicted syncope recurrence when compared to total number of historical spells (likelihood ratio statistic 28.4, P < 0.0001; versus 20.4, P = 0.001), and showed a substantial effect as the number of syncope events increased. For example, syncope recurred in 22% of those with <2 spells in the previous year compared to 69% in those with >6 spells. A history of no syncope compared to any syncope in the preceding year was associated with a 1-year probability of 7% versus 46% for syncope recurrence. A study designed to detect a 50% decrease in syncope recurrence at P = 0.05 with 80% power would require 159 patients with at least 3 lifetime spells, and only 108 patients with at least 3 spells in the previous year. CONCLUSIONS: the number of syncope events in the year preceding clinical evaluation is the best predictor of syncope recurrence.

Device-related infection among patients with pacemakers and implantable defibrillators: incidence, risk factors, and consequences.

BACKGROUND: Device-related infection is a major limitation of device therapy for cardiac arrhythmia. METHODS: The authors analyzed the incidence and risk factors for cardiac device infection (CDI) among consecutive patients implanted with pacemaker (PM) or implantable cardioverter defibrillator (ICD) (including cardiac resynchronization therapy devices) at a tertiary health center in Hamilton, Ontario, Canada. Most patients with device-related infections were identified by an internal infection control system that reports any positive wound and blood cultures following surgery, between 2005 and the present. A retrospective review of patient records was also performed for all patients who received an ICD or PM between July 1, 2003 and March 20, 2007. RESULTS: A total of 24 infections were identified among 2,417 patients having device surgery (1%). Fifteen of these infections (60%) were diagnosed within 90 days of the last surgical procedure. Univariate analysis showed that patients presenting with CDI were more likely to have had a device replacement, rather than a new implant, had more complex devices (dual/triple chamber vs single), and were more likely to have had a prior lead dislodgement. Multivariate analysis found device replacement (P = 0.02) and cardiac resynchronization therapy (CRT)/dual-chamber devices (P = 0.048) to be independent predictors of infection. One patient developed septic pulmonary emboli after having laser-assisted lead extraction. No patient died and 22 patients received a new device. CONCLUSION: CDI occurs in about 1% of cases in high volume facilities. Pulse generator replacement surgery and dual- or triple-chamber device implantation were associated with a significantly increased risk of infection.