Validation of the Emory Risk Score in the Transcatheter Aortic Valve Implantation Population: A Canadian Perspective.

Background: Permanent pacemaker (PPM) implantation may be indicated post-transcatheter aortic valve implantation (TAVI). The Emory Risk Score (ERS) is a validated predictive risk score of the need for a PPM post-TAVI using a balloon-expandable valve. Our objectives were to determine the validity of the ERS in our local TAVI population with both balloon-expandable and self-expanding valves and to identify additional electrocardiographic (ECG) parameters predictive of the need for a PPM post-TAVI. Methods: Retrospective chart and electronic database reviews were performed to collect demographic and procedural information. Two expert readers reviewed all ECGs. Independent factors associated with PPM implantation were examined with multivariable logistic regression via a stepwise selection process with calculation of the area under the receiver operating characteristic curve to assess model discrimination. Results: The overall PPM implantation rate was 11.7%; rates were 9% for the Sapien 3 valves, 10% for the Evolut Pro valves, and 17% for the Evolut R valves. The ERS was found to not be predictive of need for PPM post-TAVI for the entire cohort. Right bundle branch block was the only ERS parameter independently associated with new PPM implant (8.5% vs 25%, odds ratio = 3.59, P = 0.01). No additional ECG parameters met the criteria for statistical significance. Conclusions: The poor predictive value of the ERS in determining the need for a PPM post-TAVI in our patient population suggests that further refinement of a formula (or risk-calculator) is warranted. Identification of a precise risk-calculator is likely to facilitate patient mobilization and reduce inpatient healthcare resource utilization.

Introduction: L'implantation d'un stimulateur cardiaque permanent (SCP) peut être indiquée après l'implantation valvulaire aortique par cathéter (post-IVAC). L'Emory Risk Score (ERS) est un score de prédiction du risque validé de la nécessité d'un SCP post-IVAC au moyen d'une valve expansible par ballonnet. Nous avions pour objectif de déterminer la validité de l'ERS auprès de notre population ayant eu une IVAC soit par valve expansible par ballonnet ou valve auto-expansible, et de déterminer d'autres paramètres électrocardiographiques (ECG) prédictifs de la nécessité d'un SCP post-IVAC. Méthodes: Nous avons réalisé des revues rétrospectives de dossiers et de bases de données électroniques pour collecter les données démographiques et interventionnelles. Deux experts ont lu et interprété tous les ECG. Les facteurs indépendants associés à l'implantation du SCP ont été examinés en effectuant la régression logistique multivariée par processus de sélection pas-à-pas au moyen du calcul de la surface sous la courbe caractéristique d'efficacité du récepteur afin d'évaluer la discrimination du modèle. Résultats: Le taux global d'implantation d'un SCP était de 11,7 % ; les taux étaient de 9 % pour les valves Sapien 3, de 10 % pour les valves Evolut Pro et de 17 % pour les valves Evolut R. Nous avons observé que l'ERS ne permettait pas de prédire si l'implantation d'un SCP post-IVAC était nécessaire pour la cohorte entière. Le bloc de branche droit était le seul paramètre de l'ERS indépendamment associé à la nouvelle implantation d'un SCP (8,5 % vs 25 %, rapport de cotes = 3,59, P = 0,01). Aucun autre paramètre ECG ne satisfaisait au critère de signification statistique. Conclusions: La faible valeur prédictive de l'ERS à déterminer la nécessité d'un SCP post-IVAC au sein de notre population de patients montre que des améliorations de la formule (ou calculateur de risques) sont justifiées. L'identification d'un calculateur de risques précis devrait favoriser l'adhésion des patients et réduire l'utilisation des ressources en soins de santé en milieu hospitalier.

High-impedance alerts with pulse generator-Lead mismatch.

Background: Cardiac Implantable Electronic Devices (CIED) include pulse generators and leads. In some implanting centers, it is a common practice to combine devices with leads from different companies. Case series have reported episodic high-impedance changes in Boston Scientific CIEDs with competitor leads. We investigated the incidence of high-impedance abnormalities in matched versus mismatched Boston Scientific Accolade pacemakers. Methods: A retrospective chart review identified all consecutive Boston Scientific Accolade pacemakers implanted between January 2017 and June 2019 at a Canadian tertiary care center. The primary outcome was the occurrence of transient, high-impedance changes which resulted in a switch to unipolar pacing/sensing in the absence of any other identifiable lead issue. Fisher exact tests (two-tailed, α = .05) were used to compare the incidence of outcomes in matched versus mismatched systems. Results: 514 Boston Scientific Accolade pacemakers were associated with 882 individual leads. The primary outcome occurred with 21 leads (20 Medtronic and 1 Abbott), associated with occasional pacing inhibition, presyncope, and/or early surgical revision. Mismatched lead-device pairs were significantly associated with CIED malfunction compared to matched lead-device pairs (3.3% vs. 0%, p = .0019). The median time from implant to unipolar safety switch was 12.4 months. The median follow-up time was 21.6 months. Conclusion: Use of mismatched leads with a Boston Scientific Accolade device was associated with an increased risk of undesirable changes in sensing polarity with occasional inappropriate pacing inhibition. Awareness of this interaction can allow for the institution of appropriate programming remedies and may increase scrutiny of the use of mismatched CIED systems.

Predictors of appropriate shock after generator replacement in patients with an implantable cardioverter defibrillator.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) are indicated for the primary prevention of sudden cardiac death in patients with reduced left ventricular ejection fraction (LVEF). The ongoing risk/benefit profile of an ICD at generator replacement is unknown. This study aimed to identify predictors of appropriate ICD shocks and therapies after first ICD generator replacement, and its procedure-related complications. METHODS: We conducted a multicenter, retrospective cohort study including patients with primary prevention ICDs who underwent generator replacement between April 2005 and July 2015 at three Canadian centers. The primary and secondary outcomes were appropriate ICD shock and any appropriate ICD therapy, respectively. Procedure-related complication rates were also reported. RESULTS: Of the 219 patients in the cohort, 61 (28%) experienced an appropriate shock while 40 (18%) experienced appropriate antitachycardia pacing over a median follow up of 2.2 years. Independent predictors of appropriate ICD shocks included: LVEF at time of replacement (adjusted odds ratio [OR] 0.4 per 10% increase in LVEF, P < .001), a history of appropriate ICD shocks prior to replacement (OR 4.9, P < .001), and a history of inappropriate ICD shocks (OR 4.2, 95%, P < .002). Similar predictors were identified for the secondary outcome of any appropriate ICD therapy. Device-related complications were reported in 25 (11%) patients, with 1 (0.5%) resulting in death, 14 (6.3%) requiring site re-operation, and 6 (2.7%) requiring cardiac surgical management. CONCLUSION: Not all primary prevention ICD patients undergoing generator replacement will require appropriate device therapies afterwards. Generator replacement is associated with several risks that should be weighed against its anticipated benefit. A comprehensive assessment of the risk-benefit profile of patients undergoing generator replacement is warranted.

Signage as an intervention on a general medicine ward to reduce unnecessary testing.

BACKGROUND: Up to 30% of medical spending in developed countries is unnecessary. Unnecessary testing is not only wasteful economically, but can be injurious to patients. Studies have shown that interventions such as education, auditing, and restrictive ordering can reduce unnecessary testing. However, these interventions are time- and resource-intensive. We conducted a study to determine if the passive intervention of placing signs on clinicians' computers was effective in reducing unnecessary testing. AIMS: To determine the effectiveness of signage on physicians' computers to limit unnecessary testing. METHODS: We identified two acute medicine wards on which all orders are placed via computer. On one ward (Ward A), we placed signs outlining recommendations regarding responsible test-ordering. Ward B acted as a control. Data was collected during a 6-month study period to determine whether test-ordering practices differed. RESULTS: A total of 1645 patients accounting for 17 786 patient-days were included in the study. Fewer tests were ordered on Ward A than Ward B (7.38 vs 8.20 tests/patient-day; P < 0.01). Additionally, significantly fewer patients on Ward B received ≥1 complete blood count/day (36.1% vs 42.5%, P = 0.04). This effect was most pronounced among patients admitted for 7-30 days. CONCLUSION: The passive intervention of placing signs on clinicians' computers significantly reduced unnecessary testing.

A cracking complication: Displacement of existing clavicle fracture complicating subcutaneous implantable cardioverter defibrillator implantation.

An 18 year old male with an incompletely healed clavicle fracture presented with unexplained syncope. Subsequent investigations were consistent with a diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). A subcutaneous implantable cardioverter-defibrillator (S-ICD) was successfully implanted and defibrillation threshold (DFT) testing performed as per standard protocol. Shortly following the procedure, the patient complained of pain and swelling over the left clavicle. A radiograph revealed aggravation and displacement of the underlying clavicle fracture. Surgical reduction and internal fixation was performed one week later.

Relation of Increasing QRS Duration Over Time and Cardiovascular Events in Outpatients With Heart Failure.

An increase in the duration of the QRS complex over time has been shown to be associated with poor clinical outcomes in specific subgroups of heart failure (HF) patients. There is a paucity of data on the clinical impact of increasing QRS duration on outcomes in HF with narrow QRS duration. This was a retrospective study of consecutive adult referrals to a tertiary outpatient HF clinic over a 2-year period. All patients with a narrow QRS, (<130 ms) were included. The primary outcome was mortality. Secondary outcomes were HF hospitalization and a composite of HF hospitalization, implantation of cardiac resynchronization therapy or left ventricular assist device and cardiac transplant. A total of 253 patients with 2 or more QRS measurments were included. Death occurred in 41 patients (16%), 258 HF hospitalizations occurred in 116 patients (46%) and the composite occurred in 127 patients (50%). Multivariable analyses found that a rate of QRS duration change of ≥1 ms/month was independently associated with increased mortality (odds ratio [OR] 2.26, 95% confidence interval [CI] 1.04 to 4.91), HF hospitalization (relative risk [RR] 2.01, 95% CI 1.37 to 2.94), and the composite (OR 2.40, 95%CI 1.44 to 4.02). A new QRS >130 ms was also independently associated with mortality (OR 3.27, 95%CI 1.29-8.32), HF hospitalization (RR 2.75, 95% CI 1.72 to 4.4) and the composite (OR 2.52, 95%CI 1.27 to 4.99). In conclusion, in patients with HF and a narrow baseline QRS, an increase in QRS duration of ≥1 ms per month is associated with increased mortality and HF hospitalization. HF patients may benefit from serial monitoring of QRS duration.

Is donating blood for the faint of heart? a systematic review of predictors of syncope in whole blood donors.

BACKGROUND: Adverse events during donation negatively impact the likelihood of subsequent donation. Syncope is a possible complication of blood donation in healthy individuals. This systematic review aims to identify risk factors for syncope in healthy blood donors. STUDY DESIGN AND METHODS: Medline, Embase, Cochrane, CINAHL, Web of Science, Transfusion Evidence Library, and PubMed libraries up to November 2016 were searched. Inclusion criteria were observational and interventional trials, case series including more than 10 participants, randomized controlled trials, and clinical trials. Papers required data pertaining to syncopal events separate from presyncope for inclusion. Incomplete text or non-English language versions were excluded. Papers were evaluated using the CHARMS 2014 checklist. RESULTS: From 3316 papers, 1297 unique citations were identified, and 11 were selected for data extraction. Sex, estimated blood volume, age, donor status, blood pressure, heart rate, weight, previous reaction, caffeine, sleep, and donation site were identified as risk factors for syncope during blood donation. CONCLUSION: Possible risk factors for syncope in healthy blood donors have been identified that could allow for improved screening prior to donation and potential reduction in donor attrition due to negative experiences.

Routine creatine kinase testing does not provide clinical utility in the emergency department for diagnosis of acute coronary syndromes.

BACKGROUND: Despite the high sensitivity and negative predictive value of contemporary high-sensitivity troponin T assays (hsTnT), creatine kinase (CK) continues to be routinely tested for the diagnosis of acute coronary syndrome (ACS). We conducted a study to identify the clinical utility of routine CK measurement, its relevance in clinical decision making in the era of hsTnT, and the potential cost-savings achievable by limiting its use. METHODS: We conducted a retrospective review of all adult patients presenting to a tertiary care center in the year 2017. We identified patients presenting with cardiac complaints who had non-diagnostic hsTnT and positive CK. These patients underwent chart review to determine whether a diagnosis of AMI was made. RESULTS: A total of 36,251 presentations were reviewed. 9951 had cardiac complaints and 8150 had CK measured. 82% of these patients had hsTnT and CK measured; 2012 of these patients had non-diagnostic hsTnT with positive CK. Of these 2012 patients, only 1 was subsequently diagnosed with AMI (0.012%). CK provided no diagnostic benefit over hsTnT alone in > 99.9% of cases. With a cost for CK of $4/test, we estimated that routine CK testing costs at least $32,000 per year in our center, and over $100,000 per year across the region. CONCLUSION: Routine CK testing does not provide a significant benefit to patient care and therefore represents an unnecessary system cost. Routine CK testing for the diagnosis of AMI should be eliminated from emergency departments in the era of hsTnT assays.

Characterization of a Unique Form of Arrhythmic Cardiomyopathy Caused by Recessive Mutation in LEMD2.

Nuclear envelope proteins have been shown to play an important role in the pathogenesis of inherited dilated cardiomyopathy. Here, we present a remarkable cardiac phenotype caused by a homozygous LEMD2 mutation in patients of the Hutterite population with juvenile cataract. Mutation carriers develop arrhythmic cardiomyopathy with mild impairment of left ventricular systolic function but severe ventricular arrhythmias leading to sudden cardiac death. Affected cardiac tissue from a deceased patient and fibroblasts exhibit elongated nuclei with abnormal condensed heterochromatin at the periphery. The patient fibroblasts demonstrate cellular senescence and reduced proliferation capacity, which may suggest an involvement of LEM domain containing protein 2 in chromatin remodeling processes and premature aging.

Inadvertent Removal of a Right Ventricular Pacemaker Lead by a Knotted Transvenous Pacing Wire.

We report an unusual complication of permanent pacemaker (PPM) implantation in a patient with a temporary transvenous pacemaker (TVP) in situ, in which the TVP lead formed a knot around the newly-placed right ventricular (RV) lead, complicating TVP removal. The case underscores the fact that suboptimal TVP lead placement, such as looping in the RV, can result in complications during implantation of a permanent pacemaker. HOW TO CITE THIS ARTICLE: Wiens EJ, Seifer CM et al. Inadvertent Removal of a Right Ventricular Pacemaker Lead by a Knotted Transvenous Pacing Wire. Indian J of Crit Care Med 2019;23(2):102-103.

Pregnancy in Catecholaminergic Polymorphic Ventricular Tachycardia.

OBJECTIVES: This investigation was a retrospective study of catecholaminergic polymorphic ventricular tachycardia (CPVT) patients in Canada and the Netherlands to compare pregnancy, postpartum, and nonpregnant event rates. BACKGROUND: CPVT is characterized by life-threatening arrhythmias during exertion or emotional stress. The arrhythmic risk in CPVT patients during pregnancy is unknown. METHODS: Baseline demographics, genetics, treatment, and pregnancy complications were reviewed. Event rate calculations assumed a 40-week pregnancy and 24-week postpartum period. RESULTS: Ninety-six CPVT patients had 228 pregnancies (median 2 pregnancies per patient; range: 1 to 10; total: 175.4 pregnant patient-years). The median age of CPVT diagnosis was 40.7 years (range: 12 to 84 years), with a median follow-up of 2.9 years (range: 0 to 20 years; total 448.1 patient-years). Most patients had pregnancies before CPVT diagnosis (82%). Pregnancy and postpartum cardiac events included syncope (5%) and an aborted cardiac arrest (1%), which occurred in patients who were not taking beta-blockers. Other complications included miscarriages (13%) and intrauterine growth restriction (1 case). There were 6 cardiac events (6%) during the nonpregnant period. The pregnancy and postpartum event rates were 1.71 and 2.85 events per 100 patient-years, respectively, and the combined event rate during the pregnancy and postpartum period was 2.14 events per 100 patient-years. These rates were not different from the nonpregnant event rate (1.46 events per 100 patient-years). CONCLUSIONS: The combined pregnancy and postpartum arrhythmic risk in CPVT patients was not elevated compared with the nonpregnant period. Most patients had pregnancies before diagnosis, and all patients with events were not taking beta-blockers at the time of the event.

Clinical outcomes of cardiac resynchronization therapy with and without a defibrillator in elderly patients with heart failure.

BACKGROUND: Evidence regarding the incremental benefit of cardiac resynchronization therapy (CRT) with a defibrillator (CRT-D) versus without (CRT-P) in elderly patients with heart failure is limited. We compared mortality and cardiac hospitalisation between CRT-D and CRT-P in the elderly. METHODS: A retrospective chart review identified all consecutive patients with age ≥75 with CRT implantation over the last 10 years at a Canadian tertiary care cardiac centre. Kaplan-Meier survival analyses and cumulative incidence curves were used to compare mortality and time to first cardiac hospitalisation, respectively, with CRT-D versus CRT-P over a 3 year period. Analyses were also repeated with propensity score matching based on age, sex, primary versus secondary prevention, date of implant, and Charlson Comorbidity Index. RESULTS: One hundred and seventy CRT patients were identified. A total of 128 received CRT-D while 42 received CRT-P. Median age was 79 (IQR 77-81), and the majority were male (83%). CRT-P patients had a higher burden of comorbidities (Charlson score 7, IQR 6-8) than CRT-D patients (Charlson score 5, IQR 5-7; P < 0.001). There was no significant difference in survival between the two groups in an unmatched comparison (P = 0.69) and with a propensity score-matched cohort (P = 0.91). Secondary prevention CRT-D patients had a higher risk of hospitalisation compared to primary prevention CRT-D patients; however, there was no significant difference in hospitalisation between the CRT-D and CRT-P groups. CONCLUSION: This study suggests there is no significant difference in mortality or cardiac hospitalisation between CRT-D and CRT-P in elderly patients with heart failure.

Right ventricular pacing is associated with increased rates of appropriate implantable cardioverter defibrillator shocks.

BACKGROUND: Right ventricular (RV) pacing has been associated with increased risk of pacemaker-induced cardiomyopathy, hospitalization and death among patients with implantable cardioverter defibrillators (ICDs). Little is known about its association with ventricular tachyarrhythmias. We hypothesize that RV pacing is associated with increased incidence of appropriate ICD shocks and death. METHODS: Retrospective study of consecutive patients with de novo ICD insertion (excluding cardiac resynchronization therapy devices) from a single tertiary care center. Patients were classified into <10% RV pacing (low-pace group) and ≥10% RV pacing (high-pace group). Data were compared using two-tailed t tests and Fisher's exact test. Binomial logistic regression was performed to identify predictors of appropriate ICD therapies. RESULTS: A total of 178 patients (54 high paced and 124 low paced) were included. Mean follow-up was 43 ± 11 months. Appropriate shocks occurred in 27 patients (15%) and were significantly higher in the high-pace group (35% vs. 10%, p = 0.008), as the number of deaths (31% vs. 11%, p = 0.001). Binary logistic regression showed a significantly increased risk of shock (OR 2.99, p = 0.01) and death (OR 3.61, p = 0.002) in high-paced patients. Multivariable analysis showed no difference in risk of shocks based on age, sex or ejection fraction. Older patients had higher risk of death. CONCLUSIONS: In this population of ICD patients, those with a high prevalence of RV pacing experienced more shocks for VF/VT and had higher mortality. Further studies should be done to determine whether minimizing RV pacing reduces arrhythmias, shock burden and death in patients with ICDs.

Atrial fibrillation in elderly patients with implantable loop recorders for unexplained syncope.

BACKGROUND: An implantable loop recorder (ILR) assists in the diagnosis of unexplained syncope and atrial fibrillation (AF). Both become prevalent with age. Limited data exist describing the incidence of AF as the diagnostic rhythm underlying syncope in the elderly. This study aims to report the incidence of AF in older adults with ILRs for unexplained syncope and identify clinical characteristics associated with AF in this population. METHODS: Retrospective observational study on patients with unexplained syncope seen in syncope clinics from two Canadian centers. Participants were ≥65 years old, without a history of AF, and received an ILR for unexplained syncope. Data were collected from patient's clinic charts. Arrhythmia diagnosis was based on ILR electrocardiogram reading during syncope (symptom-rhythm correlation). Fisher's exact test and the Student's t test were used to compare participants with and without AF. RESULTS: In our cohort of 222 patients, 124 were females and 98 were males. Mean age at implant was 80 ± 8 years. Arrhythmia was diagnosed in 98 patients (44.1%). Median time to diagnosis was 18 months. AF was diagnosed in 17 (7.7%) participants. There were fewer males in the AF group than the no AF group (11.8%, 46.8%, p = 0.01). Age, baseline EKG, and prevalence of hypertension, diabetes, stroke, or ischemic heart disease were not statistically different between patients with AF and without AF. CONCLUSIONS: Atrial fibrillation was a common diagnostic rhythm in this cohort of adults, aged 65 and older, with ILRs for unexplained syncope. It was observed more frequently in females.

Atrial fibrillation detected initially during acute medical illness: A systematic review.

OBJECTIVE:: There is uncertainty about the incidence of and prognosis associated with atrial fibrillation that is documented for the first time in the setting of an acute stressor, such as surgery or medical illness. Our objective was to perform a systematic review of the incidence and long-term recurrence rates for atrial fibrillation occurring transiently with stress in the setting of acute medical illness. DATA SOURCES:: Medline, Embase and Cochrane Central to September 2017. STUDY SELECTION:: We included retrospective and prospective observational studies, and randomised controlled trials. The population of interest included patients hospitalised for medical (i.e. non-surgical) illness who developed newly diagnosed atrial fibrillation. Studies were included if they included data on either the incidence of atrial fibrillation or the rate of atrial fibrillation recurrence in atrial fibrillation occurring transiently with stress patients following hospital discharge. DATA EXTRACTION:: Two reviewers collected data independently and in duplicate. We characterised each study's methodology for ascertainment of prior atrial fibrillation history, atrial fibrillation during hospitalisation and atrial fibrillation recurrence after hospital discharge. DATA SYNTHESIS:: Thirty-six studies reported the incidence of atrial fibrillation. Ten used a prospective design and included a period of continuous electrocardiographic (ECG) monitoring. Atrial fibrillation incidence ranged from 1% to 44%, which was too heterogeneous to justify meta-analysis ( I2=99%). In post-hoc meta-regression models, the use of continuous ECG monitoring explained 13% of the variance in atrial fibrillation incidence, while care in an intensive care unit explained none. Two studies reported the long-term rate of atrial fibrillation recurrence following atrial fibrillation occurring transiently with stress. Neither of these studies used prospective, systematic monitoring. Recurrence rates at 5 years ranged from 42% to 68%. CONCLUSIONS:: The incidence of atrial fibrillation with medical illness may be as high as 44%, with higher estimates in reports using continuous ECG monitoring. Within 5 years following hospital discharge, atrial fibrillation recurrence is documented in approximately half of patients; however, the true rate may be higher. PROTOCOL REGISTRATION: PROSPERO CRD42016043240.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke.

OBJECTIVES: The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF. METHODS: In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis. RESULTS: We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05). CONCLUSIONS: Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke.

OBJECTIVES: The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF. METHODS: In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis. RESULTS: We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05). CONCLUSIONS: Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Implantable loop recorders in the real world: a study of two Canadian centers.

PURPOSE: Implantable loop recorders (ILRs) are increasingly being used for ambulatory electrocardiography. We sought to evaluate ILR indications, diagnostic yield, ILR-guided interventions, and complications in two Canadian centers. METHODS: This was a retrospective study using electronic medical records to identify ILR implants at Queen's University and the University of Manitoba. Information was collected on patient characteristics, medications, indication for implant, results of prior investigations, diagnostic outcome, and subsequent management. RESULTS: A total of 540 patients were identified; 386 had completed monitoring at time of analysis. Forty patients were lost to follow-up. Indications were unexplained syncope 84.8%, palpitations 12.8%, and suspected atrial fibrillation 11.7%. For syncope, ILRs documented arrhythmia or conduction disorder in 46%. Most common conditions were asystole/sinus pause (22%), complete heart block (10.4%), and atrial fibrillation (AF) (6.9%). After ILR diagnosis, 39.9% of implanted patients received pacemaker/ICD and 2.7% underwent catheter ablation. For palpitations, ILRs documented arrhythmia or conduction disorder in 60.4%. Most common conditions were AVNRT, AF, complete heart block, and ventricular tachycardia. After diagnosis, 25% underwent catheter ablation and 22.9% received pacemaker/ICD. For suspected AF, AF was diagnosed in 40%. Complications were observed in 3.3% of implanted patients: implant site infection 1.5%, non-infectious implant site pain requiring device removal or pocket revision 1.5%, 0.2% hypertrophic scar, and 0.2% device malfunction. CONCLUSIONS: An ILR has excellent diagnostic yield for syncope, palpitations, and suspected AF, and a considerable proportion of patients undergo ILR-directed interventions following monitoring. ILR implantation is a low-risk procedure.