Understanding whether vasovagal syncope is a lifelong disorder might shed insight into its physiology and affect management strategies. Accordingly, we determined the age of the first syncopal spell in adult patients who sought care for syncope.
Patients were 42 +/- 18 years old with 64% women. They had had a median 8 syncope spells (interquartile range [IQR]: 4, 20) with a median frequency of 1.0 syncopal spells per year. The range of syncopal spells was 1-3,375, and the range of duration of history of syncope was 0.003-70 years. The first syncopal spell occurred at ages 0-81 in a skewed distribution, with a marked mode age of 13 years, a median age of 18 years (IQR 12, 37), and a mean age of 26 +/- 20 years. The distributions were statistically indistinguishable across countries (P = 0.50), among Canadian regions (P = 0.69), and between the studies (P = 0.49). The same modal values were seen in males and females, and in patients or =40 years old. However, patients > or =40 years had median ages of onset older than patients
Anticoagulation in patients undergoing atrial fibrillation (AF) ablation is crucial to minimize the risk of thromboembolic complications. There are broad ranges of approaches to anticoagulation management pre and post AF ablation procedures. The purpose of this study was to determine the anticoagulation strategies currently in use in patients peri- and post AF ablation in Canada.
A Web-based national survey of electrophysiologists performing AF ablation in Canada collected data regarding anticoagulation practice prior to ablation, periprocedural bridging, and duration of postablation anticoagulation.
The survey was completed by 36 (97%) of the 37 electrophysiologists performing AF ablation across Canada. Prior to AF ablation, 58% of electrophysiologists started anticoagulation for patients with paroxysmal AF CHADS(2) scores of 0 to 1, 92% for paroxysmal AF CHADS(2) scores = 2, 83% for persistent AF CHADS(2) scores of 0 to 1, and 97% for persistent AF CHADS(2) scores = 2. For patients with CHADS(2) 0 to 1, warfarin was continued for at least 3 months by most physicians (89% for paroxysmal and 94% for persistent AF). For patients with CHADS(2) = 2 and with no recurrence of AF at 1 year post ablation, 89% of physicians continued warfarin.
Although guidelines recommend long-term anticoagulation in patients with CHADS(2) = 2, 11% of physicians would discontinue warfarin in patients with no evidence of recurrent AF 1 year post successful ablation. Significant heterogeneity exists regarding periprocedural anticoagulation management in clinical practice. Clinical trial evidence is required to guide optimal periprocedural anticoagulation and therapeutic decisions regarding long-term anticoagulation after an apparently successful catheter ablation for AF.
Comment In: Can J Cardiol. 2013 Feb;29(2):139-4122819445
There is uncertainty about the proper role of defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion.
A prospective registry was conducted at 13 sites in Canada between January 2006 and October 2007.
To document the details of DT, the reasons for not conducting DT, and the costs and complications associated with DT.
DT was conducted at implantation in 230 of 361 patients (64%). DT was more likely to be conducted for new implants compared with impulse generator replacements (71% vs 32%, P = 0.0001), but was similar for primary and secondary prevention indications (64% vs 63%, P = NS). Among patients not having DT, the reason(s) given were: considered unnecessary (44%); considered unsafe, mainly due to persistent atrial fibrillation (37%); lack of an anesthetist (20%); and, patient or physician preference (6%). When performed, DT consisted of a single successful shock > or = 10J below maximum device output in 65% of cases. A 10J safety-margin was met by 97% of patients, requiring system modification in 2.3%. Major perioperative complications occurred in 4.4% of patients having DT versus 6.6% of patients not having DT (P = NS). ICD insertion was $844 more expensive for patients having DT (P = 0.16), largely due to increased costs ($28,017 vs $24,545) among patients having impulse generator replacement (P = 0.02).
DT was not performed in a third of ICD implants, usually due to a perceived lack of need or relative contraindication.
Radiofrequency ablation (RFA) has become an accepted therapy for atrial fibrillation (AF). The objective of this study was to perform an economic evaluation of RFA versus antiarrhythmic drug therapy (AAD) as first-line treatment of symptomatic paroxysmal AF.
To estimate and compare the costs of RFA versus AAD, a decision analytic model was developed using data on AF recurrence, hospitalization rates, AAD use, and treatment crossover rates derived directly from the Randomized Trial of RFA versus AAD as First-Line Treatment of Symptomatic Atrial Fibrillation (RAAFT). Resource utilization was modeled to reflect Canadian clinical practice in AF management. Unit costs of healthcare interactions were based on available Canadian government resources and published literature. Costs were assessed based on intention-to-treat. Total expected costs were computed to include initial treatment, hospital stay, physician fees, diagnostic tests, and outpatient visits. Sensitivity analyses were performed to account for the uncertainties. The study was conducted from the third party payer's perspective and costs are reported in 2005 Canadian dollars with 3% discount rate used in the analysis.
During the 2-month blanking period following therapy selection, total average costs for RFA and AAD were $10,465 and $2,556, respectively; at 1-year follow-up, these were $12,823 and $6,053; and total 2-year cumulative total average costs were $15,303 and $14,392. Sensitivity analyses did not alter the results, suggesting the model is robust.
RFA as first-line treatment strategy in patients with symptomatic paroxysmal AF was cost neutral 2 years after the initial procedure compared to AAD.
There is emerging evidence for clinical superiority of catheter ablation over rate and rhythm control strategies in paroxysmal atrial fibrillation (PAF). The objective of this study was to compare costs related to medical therapy versus catheter ablation for PAF in Ontario (Canada).
Costs related to medical therapy in the analysis included the cost of anticoagulation, rate and rhythm control medications, noninvasive testing, physician follow-up visits, and hospital admissions, as well as the cost of complications related to this management strategy. Costs related to catheter ablation were assumed to include the cost of the ablation tools (electroanatomic mapping or intracardiac echocardiography-guided pulmonary vein ablation), hospital and physician billings, and costs related to periprocedural medical care and complications. Costs related to these various elements were obtained from the Canadian Registry of Atrial Fibrillation (CARAF), government fee schedules, and published data. Sensitivity analyses looking at a range of initial success rates (50-75%) and late attrition rates (1-5%), prevalence of congestive heart failure (CHF) (20-60%), as well as discounting varying from 3% to 5% per year were performed.
The cost of catheter ablation ranged from $16,278 to $21,294, with an annual cost of $1,597 to $2,132. The annual cost of medical therapy ranged from $4,176 to $5,060. Costs of ongoing medical therapy and catheter ablation for PAF equalized at 3.2-8.4 years of follow-up.
Catheter ablation is a fiscally sensible alternative to medical therapy in PAF with cost equivalence after 4 years.
Patients with atrial fibrillation (AF) are at increased risk for ischemic stroke. In patients who have suffered a stroke, screening for AF is routinely performed only for a short period after the stroke as part of the evaluation for possible causes. If AF is detected after an ischemic stroke, oral anticoagulation therapy is recommended for secondary stroke prevention. In 25% to 30% of stroke patients, the stroke mechanism cannot be determined (cryptogenic stroke). The incidence of paroxysmal AF undetected by short-term monitoring in patients with cryptogenic stroke is unknown, but has important therapeutic implications on patient care. The optimum monitoring duration and method of AF detection after stroke are unknown. The purpose of this study is to evaluate the incidence of AF and time to AF detection in patients with cryptogenic stroke using an insertable cardiac monitor.
The CRYSTAL AF trial is a randomized prospective study to evaluate a novel approach to long-term monitoring for AF detection in patients with cryptogenic stroke. Four hundred fifty cryptogenic stroke patients (by definition, without a history of AF) will be enrolled at approximately 50 sites in Europe, Canada, and the United States. Patients will be randomized in a 1:1 fashion to standard arrhythmia monitoring (control arm) or implantation of the subcutaneous cardiac monitor (Reveal XT; Medtronic, Inc, Minneapolis, MN) (continuous monitoring arm).
The primary end point is time to detection of AF within 6 months after stroke. The clinical follow-up period will be at least 12 months. Study completion is expected at the end of 2012.
Comment In: Am Heart J. 2010 Dec;160(6):e43; author reply e4521146646
Device-related infection is a major limitation of device therapy for cardiac arrhythmia.
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.
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.
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.
The DISCERN AF study (Discerning Symptomatic and Asymptomatic Episodes Pre and Post Radiofrequency Ablation of Atrial Fibrillation) monitored atrial fibrillation (AF) using an implantable cardiac monitor (ICM) to assess the incidence and predictors of asymptomatic AF before and after catheter ablation.
Patients with symptomatic AF underwent implantation of an ICM with an automated AF detection algorithm 3 months before and 18 months after ablation. Patients kept a standardized diary to record symptoms of arrhythmia, and ICM data were downloaded every 3 months. All episodes were blindly adjudicated and correlated with the diary. Asymptomatic recurrences were ICM episodes of 2 minutes or longer with no associated diary symptoms.
Fifty patients had 2355 ICM episodes. Of these, 69.0% were true AF/atrial flutter (AFL)/atrial tachycardia (AT); 16.0%, sinus with extrasystoles; 11.0%, artifact; and 4.0%, sinus arrhythmia. Total AF/AFL/AT burden was reduced by 86% from a mean (SD) of 2.0 (0.5) h/d per patient before to 0.3 (0.2) h/d per patient after ablation (P
Comment In: JAMA Intern Med. 2013 Jan 28;173(2):156-723266835
Empiric pacemaker compared with a monitoring strategy in patients with syncope and bifascicular conduction block--rationale and design of the Syncope: Pacing or Recording in ThE Later Years (SPRITELY) study.
This study seeks to identify the optimal management strategy for patients with syncope in the context of bifascicular block and preserved left ventricular systolic function.
This multicentre, randomized, open label, parallel group pragmatic randomized trial will test the hypothesis that a strategy of empiric permanent pacemaker implantation in patients with syncope and bifascicular heart block improves future outcome more effectively than a strategy of therapy guided by prolonged monitoring with an implantable loop recorder (ILR). A total of 120 patients with bifascicular block, preserved left ventricular function, and = 1 syncopal spell in the preceding year will be randomized to receive a permanent pacemaker or ILR in at least 20 centres in Canada, the USA, Asia, and Europe. The primary outcome measure will be a composite of Major Adverse Study-Related Events (MASRE) in a 2-year observation period, wherein the events are death, syncope, symptomatic bradycardia, asymptomatic diagnostic bradycardia, and acute and chronic device complications. Prespecified secondary endpoints will include syncope symptoms, quality of life, and economic burden.
This trial will provide high-level and generalizable evidence for the use of either permanent pacing or implantable loop recorders as a first line intervention for patients with syncope, preserved systolic function, and bifascicular block.
Dual-chamber pacemakers frequently document atrial fibrillation (AF) in patients without symptoms. Pacemaker-detected AF is associated with a 2.5-fold increased risk of stroke, although it is not established whether oral anticoagulation reduces this risk. This study sought to determine the prevalence and predictors of pacemaker-detected AF and to document current oral anticoagulant use.
A retrospective analysis included all patients from a single academic hospital who had pacemakers capable of documenting AF. Blinded evaluation of all echocardiograms conducted within 6 months of implantation was performed.
Of 445 patients, pacemaker-detected AF was present in 246 (55.3%), who were older (74.3 ± 13.7 years vs 71.7 ± 14.4, P = 0.046), more likely to have a history of clinical AF (29.7% vs 19.1%, P = 0.01), and had a larger left atrial volume index (34.4 ± 11.8 mL/m(2) vs 30.0 ± 9.9 mL/m(2), P = 0.019) than the patients without pacemaker-detected AF. Among patients without a clinical history of AF, left atrial volume index was higher among those with pacemaker-detected AF (33.7 ± 11.3 mL/m(2) vs 29.0 ± 10.1 mL/m(2), P = 0.034). Anticoagulants were used in 35.3% of patients with pacemaker-detected AF, compared with 21.6% of patients without (P