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.).

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.

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.

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.

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.

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.

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.

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.

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.