Long-Term Outcomes of Resynchronization-Defibrillation for Heart Failure.

BACKGROUND: The Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT) showed a greater benefit with respect to mortality at 5 years among patients who received cardiac-resynchronization therapy (CRT) than among those who received implantable cardioverter-defibrillators (ICDs). However, the effect of CRT on long-term survival is not known. METHODS: We randomly assigned patients with New York Heart Association (NYHA) class II or III heart failure, a left ventricular ejection fraction of 30% or less, and an intrinsic QRS duration of 120 msec or more (or a paced QRS duration of 200 msec or more) to receive either an ICD alone or a CRT defibrillator (CRT-D). We assessed long-term outcomes among patients at the eight highest-enrolling participating sites. The primary outcome was death from any cause; the secondary outcome was a composite of death from any cause, heart transplantation, or implantation of a ventricular assist device. RESULTS: The trial enrolled 1798 patients, of whom 1050 were included in the long-term survival trial; the median duration of follow-up for the 1050 patients was 7.7 years (interquartile range, 3.9 to 12.8), and the median duration of follow-up for those who survived was 13.9 years (interquartile range, 12.8 to 15.7). Death occurred in 405 of 530 patients (76.4%) assigned to the ICD group and in 370 of 520 patients (71.2%) assigned to the CRT-D group. The time until death appeared to be longer for those assigned to receive a CRT-D than for those assigned to receive an ICD (acceleration factor, 0.80; 95% confidence interval, 0.69 to 0.92; P = 0.002). A secondary-outcome event occurred in 412 patients (77.7%) in the ICD group and in 392 (75.4%) in the CRT-D group. CONCLUSIONS: Among patients with a reduced ejection fraction, a widened QRS complex, and NYHA class II or III heart failure, the survival benefit associated with receipt of a CRT-D as compared with ICD appeared to be sustained during a median of nearly 14 years of follow-up. (RAFT ClinicalTrials.gov number, NCT00251251.).

Mortality Risk Increases With Clustered Ventricular Arrhythmias in Patients With Implantable Cardioverter-Defibrillators.

OBJECTIVES: This study sought to examine the adverse prognosis associated with ventricular arrhythmia clusters that falls outside the current electrical storm definition. BACKGROUND: Electrical storm is most frequently defined as a cluster of ≥3 episodes of ventricular arrhythmia (VA) in a 24-h period. This definition has been associated with adverse cardiovascular outcomes and mortality, but the effect of lesser and greater clustering of arrhythmias has not been described. METHODS: Among all patients in the Resynchronization in Ambulatory Heart Failure trial, 14,515 implantable cardioverter-defibrillator-detected events with data available were rigorously adjudicated in blinded fashion. Arrhythmia incidence was examined for clustering, defined as 2 or more VA events occurring within 3 months. The prognostic importance of clustering was analyzed by varying the cluster length and number of events used to define a cluster. Mortality rates of groups with clustered arrhythmias were compared to patients with no arrhythmia or with unclustered arrhythmia. RESULTS: The trial included 1,764 patients, among whom 465 patients had two or more VA episodes within 3 months, whereas 406 had unclustered arrhythmias. Compared to patients with no arrhythmia, patients experiencing unclustered VA had increased risk of death (hazard ratio [HR]: 1.45; 95% confidence interval [CI]: 1.09 to 1.93; p = 0.011), whereas the risk was even higher in patients with clustered arrhythmia (HR: 2.68; 95% CI: 2.13 to 3.36; p < 0.0001). Mortality risk increased with higher VA burden (number of VAs in a cluster) and shorter cluster length. This was observed in all groups tested, including the cluster with the least VA burden in the longest cluster length tested (2 VA episodes occurring within 3 months) (mortality HR: 2.85; 95% CI: 1.95 to 4.17; p < 0.0001). Although clustered arrhythmias terminated with antitachycardia pacing were associated with increased mortality, clusters terminated with implantable cardioverter-defibrillator shocks were associated with still higher mortality risk. CONCLUSIONS: Significant adverse prognostic association of clustered VAs is observable with even 2 VA events within 3 months and increases with higher cluster density.

Risk of stroke and other adverse outcomes in patients with perioperative atrial fibrillation 1 year after non-cardiac surgery.

AIMS: To determine the 1-year risk of stroke and other adverse outcomes in patients with a new diagnosis of perioperative atrial fibrillation (POAF) after non-cardiac surgery. METHODS AND RESULTS: The PeriOperative ISchemic Evaluation (POISE)-1 trial evaluated the effects of metoprolol vs. placebo in 8351 patients, and POISE-2 compared the effect of aspirin vs. placebo, and clonidine vs. placebo in 10 010 patients. These trials included patients with, or at risk of, cardiovascular disease who were undergoing non-cardiac surgery. For the purpose of this study, we combined the POISE datasets, excluding 244 patients who were in atrial fibrillation (AF) at the time of randomization. Perioperative atrial fibrillation was defined as new AF that occurred within 30 days after surgery. Our primary outcome was the incidence of stroke at 1 year of follow-up; secondary outcomes were mortality and myocardial infarction (MI). We compared outcomes among patients with and without POAF using multivariable adjusted Cox proportional hazards models. Among 18 117 patients (mean age 69 years, 57.4% male), 404 had POAF (2.2%). The stroke incidence 1 year after surgery was 5.58 vs. 1.54 per 100 patient-years in patients with and without POAF, adjusted hazard ratio (aHR) 3.43, 95% confidence interval (CI) 2.00-5.90; P < 0.001. Patients with POAF also had an increased risk of death (incidence 31.37 vs. 9.34; aHR 2.51, 95% CI 2.01-3.14; P < 0.001) and MI (incidence 26.20 vs. 8.23; aHR 5.10, 95% CI 3.91-6.64; P < 0.001). CONCLUSION: Patients with POAF have a significantly increased risk of stroke, MI, and death at 1 year. Intervention studies are needed to evaluate risk reduction strategies in this high-risk population.

Comparison of Usefulness of Cardiac Resynchronization Therapy in Patients With Type 1 Myotonic Dystrophy With Versus Without Left Bundle Branch Block.

Patients with type 1 myotonic dystrophy show reduced left ventricular systolic function in the presence of left bundle branch block due to electromechanical dys-synchrony. Our prospective study tracked a cohort of 64 type 1 myotonic dystrophy patients that demonstrated a high burden of atrial and ventricular arrhythmias and conduction delays. Of these patients, 12 (19%) patients had left bundle branch block, which was associated with reduced left ventricular systolic function. Eight of these patients received cardiac resynchronization therapy devices resulting in reduction of median QRS complex duration from 173 to 166 ms (p = 0.04), and improvement in median left ventricular ejection fraction from 37% to 46% (p = 0.007). In conclusion, cardiac resynchronization therapy device therapy is both feasible and effective in treating advanced cardiac disease in this vulnerable group of patients by improving left ventricular function.

Ventricular tachycardia in patients with type 1 myotonic dystrophy: a case series.

BACKGROUND: Type 1 myotonic dystrophy (DM1) is associated with a variety of cardiac conduction abnormalities and the frequent need for permanent pacing. However, the role of ventricular tachycardia (VT) and the implied risk of sudden cardiac death (SCD) is poorly understood. CASE SUMMARY: This study examined a 56-patient DM1 cohort of men and women, and identified five patients (two females and three males) with ventricular arrhythmias (8.9%). Patients were reviewed on a case-by-case basis, with their clinical presentation and management of VT and the associated cardiomyopathy indicated. Patient cardiac function was determined by 12-lead electrocardiogram, 48-h Holter monitor, and transthoracic echocardiography. These patients were therefore suitable candidates for implantable cardioverter-defibrillator implantation and received these devices; four of the five patients also received cardiac resynchronization therapy. Medical therapies included angiotensin converting enzyme inhibition, mineralocorticoid receptor antagonist, and following device implantation, beta-blocker therapy was initiated. DISCUSSION: Our case series demonstrates the prevalence of VT in patients with DM1 highlighting the associated risks of SCD in this patient population. The burden of ventricular arrhythmias, advanced conduction disease, and cardiomyopathy are best treated with a combination of device and medical therapies.

A Population-Based Study of Adherence to Guideline Recommendations and Appropriate-Use Criteria for Implantable Cardioverter Defibrillators.

Studies evaluating physician adherence to guideline recommendations for implantable cardioverter defibrillator (ICD) therapy are sparse, and none exist for the application of appropriate-use criteria (AUC) in clinical practice. As part of a quality improvement initiative, a review of all ICD procedures was performed from January 1, 2015 to December 31, 2016 in Alberta, Canada, to evaluate the proportion of patients receiving appropriate ICD therapy and to identify reasons for nonadherence. Our device-implant process involves an electrophysiologist or implanting cardiologist evaluation, reminders of ICD eligibility criteria on the device requisition, and peer-review consensus. Implants were classified according to the 2008 American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) ICD guidelines, 2013 Canadian Cardiovascular Society (CCS) Cardiac Resynchronization Therapy (CRT) guidelines, and 2013 AUC. There were 1,300 ICD procedures performed, and the mean age was 63.8 ± 12.9 years; 79% were male; the mean ejection fraction was 0.32 ± 0.13, and 69% were for primary prevention. Among all implants, < 1% were discordant with American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) recommendations. Among CRT implants, 10% were inconsistent with Canadian Cardiovascular Society (CCS) recommendations. According to AUC, 92% of implants were appropriate. Reasons for nonadherence to ACC/AHA/HRS recommendations included QRS width < 120 msec (n = 3), LVEF > 0.35 (n = 2) and recent myocardial infarction (MI) (n = 1). The most common reason for nonadherence to AUC was the absence of criteria for classification (n = 57, 4%). In this population-based study, we found that a process of specialist evaluation, eligibility reminders on device forms, and peer-review consensus may improve adherence to guideline recommendations and AUC for ICD therapy.

Differentiating Ventricular From Supraventricular Arrhythmias Using the Postpacing Interval After Failed Antitachycardia Pacing.

BACKGROUND: Implantable cardioverter defibrillator arrhythmia discrimination algorithms often are unable to discriminate ventricular from supraventricular arrhythmias. We sought to evaluate whether the response to antitachycardia pacing (ATP) in patients with an implantable cardioverter defibrillator could further discriminate ventricular from supraventricular arrhythmias in patients receiving ATP. METHODS AND RESULTS: All episodes of ventricular or supraventricular tachycardia where ATP was delivered in patients enrolled in RAFT (Cardiac-Resynchronization Therapy for Mild-to-Moderate Heart Failure Trial) were included. RAFT randomized 1798 patients with New York Heart Association class II/III heart failure, left ventricular ejection fraction ≤30%, and QRS duration of ≥120 ms to a implantable cardioverter defibrillator±cardiac resynchronization therapy. The tachycardia cycle lengths (TCLs) before and after the delivery of ATP and the postpacing intervals were assessed. Overall, 10 916 ATP attempts were reviewed for 8150 tachycardia episodes in 924 patients. After excluding tachycardias where ATP terminated the episode or where the specific mechanism of the tachycardia was uncertain, we analyzed 3676 ATP attempts delivered for 2046 tachycardia episodes in 541 patients. A shorter difference between postpacing interval and TCL (PPI-TCL) was more likely to be associated with ventricular tachycardia than with supraventricular tachyarrhythmia (138.1±104.2 versus 277.4±126.9 ms; p<0.001). Analysis of the receiver operator curve for the PPI-TCL revealed an area under the curve of 0.803 (p<0.001; 95% confidence interval, 0.784-0.822). The majority of tachycardias with a PPI-TCL >360 ms were supraventricular with a PPI-TCL value of ≤360 ms having a sensitivity of 97.4% and specificity of 28.3% for ventricular tachycardia. CONCLUSIONS: The ATP response, specifically the PPI-TCL, can further discriminate ventricular from supraventricular arrhythmias in patients with implantable cardioverter defibrillators when the currently available discriminators fail. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00251251.

Predictors, Prognosis, and Management of New Clinically Important Atrial Fibrillation After Noncardiac Surgery: A Prospective Cohort Study.

BACKGROUND: Despite the frequency of new clinically important atrial fibrillation (AF) after noncardiac surgery and its increased association with the risk of stroke at 30 days, there are limited data informing their prediction, association with outcomes, and management. METHODS: We used the data from the PeriOperative ISchemic Evaluation trial to determine, in patients undergoing noncardiac surgery, the association of new clinically important AF with 30-day outcomes, and to assess management of these patients. We also aimed to derive a clinical prediction rule for new clinically important AF in this population. We defined new clinically important AF as new AF that resulted in symptoms or required treatment. We recorded an electrocardiogram 6 to 12 hours postoperatively and on the 1st, 2nd, and 30th days after surgery. RESULTS: A total of 211 (2.5% [8351 patients]; 95% confidence interval, 2.2%-2.9%) patients developed new clinically important AF within 30 days of randomization (8140 did not develop new AF). AF was independently associated with an increased length of hospital stay by 6.0 days (95% confidence interval, 3.5-8.5 days) and vascular complications (eg, stroke or congestive heart failure). The usage of an oral anticoagulant at the time of hospital discharge among patients with new AF and a CHADS2 score of 0, 1, 2, 3, and ≥4 was 6.9%, 10.2%, 23.0%, 9.4%, and 33.3%, respectively. Two independent predictors of patients developing new clinically important AF were identified (ie, age and surgery). The prediction rule included the following factors and assigned weights: age ≥85 years (4 points), age 75 to 84 years (3 points), age 65 to 74 years (2 points), intrathoracic surgery (3 points), major vascular surgery (2 points), and intra-abdominal surgery (1 point). The incidence of new AF based on scores of 0 to 1, 2, 3 to 4, and 5 to 6 was 0.5%, 1.0%, 3.1%, and 5.3%, respectively. CONCLUSIONS: Age and surgery are independent predictors of new clinically important AF in the perioperative setting. A minority of patients developing new clinically important AF with high CHADS2 scores are discharged on an oral anticoagulant. There is a need to develop effective and safe interventions to prevent this outcome and to optimize the management of this event when it occurs.

Cardiac Resynchronization Therapy Reduces Ventricular Arrhythmias in Primary but Not Secondary Prophylactic Implantable Cardioverter Defibrillator Patients: Insight From the Resynchronization in Ambulatory Heart Failure Trial.

BACKGROUND: The RAFT (Resynchronization in Ambulatory Heart Failure Trial) demonstrated that cardiac resynchronization therapy (CRT) reduced both mortality and heart failure hospitalizations in patients with functional class II or III heart failure and widened QRS. We examined the influence of CRT on ventricular arrhythmias in patients with primary versus secondary prophylaxis defibrillator indications. METHODS AND RESULTS: All ventricular arrhythmias among RAFT study participants were downloaded and adjudicated by 2 blinded reviewers with an overreader for disagreements and committee review for remaining discrepancies. Incidence of ventricular arrhythmias among patients randomized to CRT-D versus implantable cardioverter defibrillator (ICD) were compared within the groups of patients treated for primary prophylaxis and for secondary prophylaxis. Of 1798 enrolled patients, 1764 had data available for adjudication and were included. Of these, 1531 patients were implanted for primary prophylaxis, while 233 patients were implanted for secondary prophylaxis; 884 patients were randomized to ICD and 880 to CRT-D. During 5953.6 patient-years of follow-up, there were 11 278 appropriate ICD detections of ventricular arrhythmias. In the primary prophylaxis group, CRT-D significantly reduced incidence ventricular arrhythmias in comparison to ICD (hazard ratio, 0.86; 95% confidence interval, 0.74-0.99; P=0.044). This effect was not seen in the secondary prophylaxis group (hazard ratio, 1.14; 95% confidence interval, 0.82-1.58; P=0.45). CRT-D was not associated with significant differences in overall ventricular arrhythmia burden in either group. CONCLUSIONS: CRT reduced the rate of onset of new ventricular arrhythmias detected by ICDs in patients without a history of prior ventricular arrhythmias. This effect was not observed among patients who had prior ventricular arrhythmias. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00251251.

Left ventricular lead position and outcomes in the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT).

BACKGROUND: Conflicting data exist regarding the association between left ventricular (LV) lead position and benefit from cardiac resynchronization therapy. We evaluated the relationships between LV lead positions and the risk of death or hospitalization for heart failure (HF) in the cardiac resynchronization therapy arm of the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT). METHODS: LV lead position was categorized by site investigator (MD) and in a chest radiograph core laboratory (CXR) as "anterior," "lateral," or "posterior" in the short axis, and "basal," "mid," or "apical" in the long axis. Agreement between MD and CXR LV lead position classification was evaluated and the independent relationship between LV lead position and clinical outcome was assessed using Cox multivariable models. RESULTS: Agreement between MD and CXR LV lead position was poor (κ ≤ 0.26). Over 39 ± 20 months, 140 of 447 (31.3%) patients met the RAFT primary end point (death or HF hospitalization). In adjusted analyses, neither MD-determined nor CXR-determined anterior or apical LV lead position was significantly associated with the primary outcome. However, CXR-defined apical LV lead position was associated with a higher risk of HF hospitalization (hazard ratio, 1.99; P = 0.004). CONCLUSIONS: Poor agreement between implanting physician and core lab CXR-based categorizations of LV lead position was observed. Neither categorization method resulted in significant associations between apical or anterior LV lead position and the risk of the composite primary outcome of death or heart failure hospitalization. However, CXR-defined apical lead position was associated with increased risk of HF hospitalization.

Cardiac resynchronization therapy in patients with permanent atrial fibrillation: results from the Resynchronization for Ambulatory Heart Failure Trial (RAFT).

BACKGROUND: Cardiac resynchronization (CRT) prolongs survival in patients with systolic heart failure and QRS prolongation. However, most trials excluded patients with permanent atrial fibrillation. METHODS AND RESULTS: The Resynchronization for Ambulatory Heart Failure Trial (RAFT) randomized patients to an implantable cardioverter defibrillator (ICD) or ICD+CRT, stratified by the presence of permanent atrial fibrillation. Patients with permanent atrial fibrillation were randomized to CRT-ICD (n=114) or ICD (n=115). Patients receiving a CRT-ICD were similar to those receiving an ICD: age (71.6±7.3 versus 70.4±7.7 years), left ventricular ejection fraction (22.9±5.3% versus 22.3±5.1%), and QRS duration (151.0±23.6 versus 153.4±24.7 ms). There was no difference in the primary outcome of death or heart failure hospitalization between those assigned to CRT-ICD versus ICD (hazard ratio, 0.96; 95% CI, 0.65-1.41; P=0.82). Cardiovascular death was similar between treatment arms (hazard ratio, 0.97; 95% CI, 0.55-1.71; P=0.91); however, there was a trend for fewer heart failure hospitalizations with CRT-ICD (hazard ratio, 0.58; 95% CI, 0.38-1.01; P=0.052). The change in 6-minute hall walk duration between baseline and 12 months was not different between treatment arms (CRT-ICD: 19±84 m versus ICD: 16±76 m; P=0.88). Patients treated with CRT-ICD showed a trend for a greater improvement in Minnesota Living with Heart Failure score between baseline and 6 months (CRT-ICD: 41±21 to 31±21; ICD: 33±20 to 28±20; P=0.057). CONCLUSIONS: Patients with permanent atrial fibrillation who are otherwise CRT candidates appear to gain minimal benefit from CRT-ICD compared with a standard ICD.

Complications associated with revision of Sprint Fidelis leads: report from the Canadian Heart Rhythm Society Device Advisory Committee.

BACKGROUND: It has been observed that replacement of an implantable cardioverter-defibrillator generator in response to a device advisory may be associated with a substantial rate of complications, including death. The risk of lead revision in response to a lead advisory has not been determined previously. METHODS AND RESULTS: Twenty-five implantable cardioverter-defibrillator implantation and follow-up centers from the Canadian Heart Rhythm Society Device Advisory Committee were surveyed to assess complication rates as a result of lead revisions due to the Sprint Fidelis advisory issued in October 2007. As of June 1, 2009, there had been 310 lead failures found in 6237 Sprint Fidelis leads in Canada (4.97%) over a follow-up of 40 months. There were 469 leads to be revised, 66% for confirmed fracture. Of the patients who underwent revision, 95% had a new lead inserted, whereas 4% had a pace/sense lead added. The lead was removed in 248 cases (53%), by simple traction in 61% and by laser lead extraction in 33%. Complications were encountered in 14.5% of the lead revisions; 7.25% of these were major, whereas 7.25% were minor. There were 2 deaths (0.43%). The overall risk of complications (19.8%) was greater in those who underwent lead removal at the time of revision than in those whose leads were abandoned (8.6%; P=0.0008). CONCLUSIONS: The overall rate of major complications that arose from lead revision due to the Sprint Fidelis advisory was significant. This must be taken into account when lead revision is planned in those patients who have not yet demonstrated an abnormality in lead performance.

Anticoagulation of patients on chronic warfarin undergoing arrhythmia device surgery: wide variability of perioperative bridging in Canada.

BACKGROUND: In patients undergoing cardiac rhythm device surgery, it is common practice to discontinue oral anticoagulation and to perform heparin bridging in order to reduce the risk of bleeding and minimize the risk of thromboembolic events. OBJECTIVE: The purpose of this study was to determine the perioperative anticoagulation strategies currently in use. METHODS: A survey presented four clinical scenarios of patients on oral anticoagulation undergoing cardiac rhythm device surgery. The scenarios represented a gradient of perceived thromboembolic risk based on the presence of atrial fibrillation, a mechanical heart valve, previous stroke, and the remainder of the CHADS(2) risk factors (congestive heart failure, hypertension, age >75 years, diabetes, previous stroke or transient ischemic attack). Respondents were offered six options that included discontinuing oral anticoagulation without heparin, three different heparin bridging protocols, and ongoing oral anticoagulation with reduced or therapeutic dose warfarin. RESULTS: Based on responses from 38 (61%) of 62 electrophysiologists surveyed across Canada, 83% of respondents held warfarin without bridging in a low-risk, 78-year-old patient with atrial fibrillation (CHADS(2) score 1). In three higher-risk patient scenarios, 67% to 100% of respondents chose heparin bridging or ongoing warfarin; 38% to 72% of respondents chose heparin bridging, with 23% to 36% choosing variable use of ongoing warfarin. In all three cases where respondents indicated that they would bridge, each of the three heparin regimens was chosen by at least 20% of respondents. CONCLUSION: There is a wide range of approaches to perioperative management in patients on oral anticoagulation undergoing cardiac rhythm device surgery. Clinical equipoise is evident and supports the need for comparative studies.

Formation of a national network for rapid response to device and lead advisories: The Canadian Heart Rhythm Society Device Advisory Committee.

The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned to respond to advisories regarding cardiac rhythm device and lead performance on behalf of the CHRS. In the event of an advisory, the Chair uses an e-mail network to disseminate advisory information to Committee members broadly representative of the Canadian device community. A consensus recommendation is prepared by the Committee and made available to all Canadian centres on the CHRS Web site after approval by the CHRS executive. This collaborative approach using an e-mail network has proven very efficient in providing a rapid national response to device advisories. The network is an ideal tool to collect specific data on implanted device system performance and allows for prompt reporting of clinically relevant data to front-line clinicians and patients.

Utilization of a national network for rapid response to the Medtronic Fidelis lead advisory: the Canadian Heart Rhythm Society Device Advisory Committee.

BACKGROUND/OBJECTIVE: The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned in 2006 to develop a mechanism for responding to advisories regarding cardiac rhythm device and lead performance. METHODS: In the event of an advisory, the Chair classifies the advisory as urgent, semi-urgent, or routine based on the nature of the threat to the patient and the number of patients affected. The Chair uses an e-mail network with the committee members to disseminate advisory information and to assemble a consensus recommendation. Committee membership is broadly representative of the Canadian device community, including both academic and nonacademic centers, adult and pediatric specialists, and includes balanced regional representation. Recommendations are approved by the CHRS executive and made available to all implant and follow-up centers on the CHRS website. RESULTS: With the Medtronic Fidelis lead advisory of October 15, 2007, the Chair classified the advisory as semi-urgent and initiated an e-mail discussion and preliminary survey of all Canadian implantable cardioverter-defibrillator (ICD) centers within 3 hours of advisory announcement. A CHRS membership statement was issued within 48 hours. Within 5 working days, sample letters to physicians and patients were posted for local adaptation and distribution. Complete data collection was obtained from all Canadian defibrillator centers. Analyses at 20, 25, 30, and 32 months suggest an accelerating course of failures (3.91% at 32 months, P <.0001), with a reduced likelihood of presentation with inappropriate shocks (from 56% to 21%, P = .0003). CONCLUSION: A collaborative approach using an e-mail network provides a mechanism for a rapid national response to device advisories. The network allows collection of focused data on implanted device system performance and facilitates timely reporting of clinically relevant data to patients and clinicians.

Bridge or continue Coumadin for device surgery: a randomized controlled trial rationale and design.

PURPOSE OF REVIEW: Many patients requiring cardiac arrhythmia device surgery are on chronic oral anticoagulation therapy. The periprocedural management of their anticoagulation presents a dilemma to physicians, particularly in the subset of patients with moderate-to-high risk of arterial thromboembolic events. Physicians have responded by treating patients with bridging anticoagulation while oral anticoagulation is temporarily discontinued. However, there are a number of downsides to bridging anticoagulation around device surgery; there is a substantial risk of significant device pocket hematoma with important clinical sequelae; bridging anticoagulation may lead to more arterial thromboembolic events and bridging anticoagulation is expensive. RECENT FINDINGS: In response to these issues, a number of centers have explored the option of performing device surgery without cessation of oral anticoagulation. The observational data suggest a greatly reduced hematoma rate with this strategy. Despite these encouraging results, most physicians are reluctant to move to operating on continued Coumadin in the absence of confirmatory data from a randomized trial. SUMMARY: We have designed a prospective, single-blind, randomized, controlled trial to address this clinical question. In the conventional arm, patients will be bridged. In the experimental arm, patients will continue on oral anticoagulation and the primary outcome is clinically significant hematoma. Our study has clinical relevance to at least 70 000 patients per year in North America.

Effect of fish oil on arrhythmias and mortality: systematic review.

OBJECTIVE: To synthesise the literature on the effects of fish oil-docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-on mortality and arrhythmias and to explore dose response and formulation effects. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, Embase, the Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, Allied and Complementary Medicine, Academic OneFile, ProQuest Dissertations and Theses, Evidence-Based Complementary Medicine, and LILACS. Studies reviewed Randomised controlled trials of fish oil as dietary supplements in humans. DATA EXTRACTION: The primary outcomes of interest were the arrhythmic end points of appropriate implantable cardiac defibrillator intervention and sudden cardiac death. The secondary outcomes were all cause mortality and death from cardiac causes. Subgroup analyses included the effect of formulations of EPA and DHA on death from cardiac causes and effects of fish oil in patients with coronary artery disease or myocardial infarction. DATA SYNTHESIS: 12 studies totalling 32 779 patients met the inclusion criteria. A neutral effect was reported in three studies (n=1148) for appropriate implantable cardiac defibrillator intervention (odds ratio 0.90, 95% confidence interval 0.55 to 1.46) and in six studies (n=31 111) for sudden cardiac death (0.81, 0.52 to 1.25). 11 studies (n=32 439 and n=32 519) provided data on the effects of fish oil on all cause mortality (0.92, 0.82 to 1.03) and a reduction in deaths from cardiac causes (0.80, 0.69 to 0.92). The dose-response relation for DHA and EPA on reduction in deaths from cardiac causes was not significant. CONCLUSIONS: Fish oil supplementation was associated with a significant reduction in deaths from cardiac causes but had no effect on arrhythmias or all cause mortality. Evidence to recommend an optimal formulation of EPA or DHA to reduce these outcomes is insufficient. Fish oils are a heterogeneous product, and the optimal formulations for DHA and EPA remain unclear.