Effect of Implantable vs Prolonged External Electrocardiographic Monitoring on Atrial Fibrillation Detection in Patients With Ischemic Stroke: The PER DIEM Randomized Clinical Trial.

Importance: The relative rates of detection of atrial fibrillation (AF) or atrial flutter from evaluating patients with prolonged electrocardiographic monitoring with an external loop recorder or implantable loop recorder after an ischemic stroke are unknown. Objective: To determine, in patients with a recent ischemic stroke, whether 12 months of implantable loop recorder monitoring detects more occurrences of AF compared with conventional external loop recorder monitoring for 30 days. Design, Setting, and Participants: Investigator-initiated, open-label, randomized clinical trial conducted at 2 university hospitals and 1 community hospital in Alberta, Canada, including 300 patients within 6 months of ischemic stroke and without known AF from May 2015 through November 2017; final follow-up was in December 2018. Interventions: Participants were randomly assigned 1:1 to prolonged electrocardiographic monitoring with either an implantable loop recorder (n = 150) or an external loop recorder (n = 150) with follow-up visits at 30 days, 6 months, and 12 months. Main Outcomes and Measures: The primary outcome was the development of definite AF or highly probable AF (adjudicated new AF lasting ≥2 minutes within 12 months of randomization). There were 8 prespecified secondary outcomes including time to event analysis of new AF, recurrent ischemic stroke, intracerebral hemorrhage, death, and device-related serious adverse events within 12 months. Results: Among the 300 patients who were randomized (median age, 64.1 years [interquartile range, 56.1 to 73.7 years]; 121 were women [40.3%]; and 66.3% had a stroke of undetermined etiology with a median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score of 4 [interquartile range, 3 to 5]), 273 (91.0%) completed cardiac monitoring lasting 24 hours or longer and 259 (86.3%) completed both the assigned monitoring and 12-month follow-up visit. The primary outcome was observed in 15.3% (23/150) of patients in the implantable loop recorder group and 4.7% (7/150) of patients in the external loop recorder group (between-group difference, 10.7% [95% CI, 4.0% to 17.3%]; risk ratio, 3.29 [95% CI, 1.45 to 7.42]; P = .003). Of the 8 specified secondary outcomes, 6 were not significantly different. There were 5 patients (3.3%) in the implantable loop recorder group who had recurrent ischemic stroke vs 8 patients (5.3%) in the external loop recorder group (between-group difference, -2.0% [95% CI, -6.6% to 2.6%]), 1 (0.7%) vs 1 (0.7%), respectively, who had intracerebral hemorrhage (between-group difference, 0% [95% CI, -1.8% to 1.8%]), 3 (2.0%) vs 3 (2.0%) who died (between-group difference, 0% [95% CI, -3.2% to 3.2%]), and 1 (0.7%) vs 0 (0%) who had device-related serious adverse events. Conclusions and Relevance: Among patients with ischemic stroke and no prior evidence of AF, implantable electrocardiographic monitoring for 12 months, compared with prolonged external monitoring for 30 days, resulted in a significantly greater proportion of patients with AF detected over 12 months. Further research is needed to compare clinical outcomes associated with these monitoring strategies and relative cost-effectiveness. Trial Registration: ClinicalTrials.gov Identifier: NCT02428140.

A 19-year study on pacemaker-related infections: a claim for using postoperative antibiotics.

BACKGROUND: Although the incidence of pacemaker-related infection (PMINF) is low, it necessitates removal of the pacing system. There is currently no consensus on antibiotics during implantation. METHODS: A prospective database on patients undergoing pacemaker surgery from 1991 to 2009 was reviewed to determine factors associated with PMINF. Specifically, three eras of antibiotic use were compared to elucidate the effect of antibiotics on PMINF: no antibiotics, perioperative antibiotics, and peri- plus postoperative antibiotics. RESULTS: There were 3,253 procedures with PMINF identified in 46 (1.4%) patients. Over 19 years, PMINF incidence fell from 3.6% (no antibiotics) to 2.9% (perioperative antibiotics), to 0.4% (peri- plus postoperative antibiotics). On univariate analysis, the following were associated with PMINF: nonuse of postoperative antibiotics (3.0% vs 0.4%, P < 0.001), year of implant (P < 0.001), repeat procedures (2.3% vs 1%, P = 0.006), nonuse of perioperative antibiotics (3.6% vs 1.3%, P = 0.027). With postoperative antibiotics, rates were significantly reduced in new implants (1/1,289 = 0.1% vs 22/967 = 2.3%, P < 0.001) and repeat procedures (7/692 = 1.0% vs 16/305 = 5.2%, P < 0.001). On multivariate analysis, the following were significant (standardized coefficients denote relative importance): postoperative antibiotics (0.776), repeat procedures (0.508), year of implant (0.142), perioperative antibiotics (0.088). CONCLUSIONS: The PMINF rate is reduced significantly by perioperative antibiotics with a further significant reduction with postoperative antibiotics. However, the reduction in PMINF rate could be a result of changes in practice in the different time eras. This study suggests consideration of perioperative followed by postoperative antibiotics to minimize pacemaker infections.

Cardiac resynchronization therapy modulation of exercise left ventricular function and pulmonary O2 uptake in heart failure.

To better understand the mechanisms contributing to improved exercise capacity with cardiac resynchronization therapy (CRT), we studied the effects of 6 mo of CRT on pulmonary O(2) uptake (Vo(2)) kinetics, exercise left ventricular (LV) function, and peak Vo(2) in 12 subjects (age: 56 ± 15 yr, peak Vo(2): 12.9 ± 3.2 ml·kg(-1)·min(-1), ejection fraction: 18 ± 3%) with heart failure. We hypothesized that CRT would speed Vo(2) kinetics due to an increase in stroke volume secondary to a reduction in LV end-systolic volume (ESV) and that the increase in peak Vo(2) would be related to an increase in cardiac output reserve. We found that Vo(2) kinetics were faster during the transition to moderate-intensity exercise after CRT (pre-CRT: 69 ± 21 s vs. post-CRT: 54 ± 17 s, P < 0.05). During moderate-intensity exercise, LV ESV reserve (exercise - resting) increased 9 ± 7 ml (vs. a 3 ± 9-ml decrease pre-CRT, P < 0.05), and steady-state stroke volume increased (pre-CRT: 42 ± 8 ml vs. post-CRT: 61 ± 12 ml, P < 0.05). LV end-diastolic volume did not change from rest to steady-state exercise post-CRT (P > 0.05). CRT improved heart rate, measured as a lower resting and steady-state exercise heart rate and as faster heart rate kinetics after CRT (pre-CRT: 89 ± 12 s vs. post-CRT: 69 ± 21 s, P < 0.05). For peak exercise, cardiac output reserve increased significantly post-CRT and was 22% higher at peak exercise post-CRT (both P < 0.05). The increase in cardiac output was due to both a significant increase in peak and reserve stroke volume and to a nonsignificant increase in heart rate reserve. Similar patterns in LV volumes as moderate-intensity exercise were observed at peak exercise. Cardiac output reserve was related to peak Vo(2) (r = 0.48, P < 0.05). These findings demonstrate the chronic CRT-mediated cardiac factors that contribute, in part, to the speeding in Vo(2) kinetics and increase in peak Vo(2) in clinically stable heart failure patients.

Reduced incidence of CIED infections with peri- and post-operative antibiotic use in CRT-P/D and ICD procedures.

Higher cardiac implantable electronic device (CIED) infection incidence has been observed with cardiac resynchronization therapy pacemaker/defibrillator (CRT-P/D) and implantable cardioverter defibrillator (ICD) devices compared to traditional pacemakers with a 1.2% rate reported at 1 year. CIED infection management has high morbidity/mortality. A previous study from this institution demonstrated significantly reduced CIED infection rate when peri/post-operative antibiotics were given for traditional pacemaker procedures. The present study examines CIED infection incidence following peri/post-operative antibiotics during CRT-P/D and ICD procedures. All patients who underwent CRT-P/D and ICD procedures from 1996 to 2015 received IV cephalexin/clindamycin pre- and 8-hours post-procedure followed by 5 days of oral therapy. There were 427 procedures (CRT-P = 146 (34.2%); CRT-D = 142 (33.3%); ICD = 139 (32.6%)). Mean age at time of procedure was 61.6 years. Mean follow-up duration was 4.26 years. CIED infection occurred in 6 patients (ICD = 4, CRT-P = 1, CRT-D = 1), amounting to a rate of 4.96/1000 device-years in total. Times to CIED infection from procedure were: 1.7, 3.5, 6.7, 7.3, 7.9 and 9.2 years. Five out of 6 infections occurred in patients with repeat procedures. This study demonstrates that administration of peri- followed by post-operative antibiotics during CRT-P/D and ICD procedures is associated with a very low rate of CIED infection. This rate of 4.96 infections per 1000 device-years compares favorably to contemporary rates of 8.9 infections per 1000 device-years. Most CIED infections occur late and well-beyond the 1-year follow-up of the Prevention of Arrhythmia Device Infection Trial, the largest trial on this question. This approach should be considered pending a definitive trial.

Impact of Cardiac Resynchronization Therapy on Daily Physical Activity in Heart Failure Patients.

PURPOSE: Cardiac resynchronization therapy (CRT) has emerged as a beneficial therapy for heart failure (HF) patients. It has been shown to enhance cardiac pump function and increase exercise capacity in patients with HF who display wide QRS complex on their electrocardiogram. To date, few studies have assessed daily physical activity (PA) in CRT patients. The objective of this pilot study was to assess the impact of CRT on the physical function and daily PA of HF patients who met the standard indications for CRT implantation. METHODS: The daily PA of 18 CRT patients was measured using a SenseWear Armband for ∼3 d. Daily PA measurements included steps/d and time spent sedentary (≤1.5 metabolic equivalent tasks), in light PA (1.6-2.9 metabolic equivalent tasks), and in moderate-vigorous PA (≥3 metabolic equivalent tasks). To assess exercise capacity, a 6-min walk test was performed pre- and post-CRT. RESULTS: There was no significant change in the 6-min walk test distance from pre- to post-CRT (383 ± 99 m at baseline vs 402 ± 104 m post-CRT). There was a decrease in total steps/d from 3405 ± 2334 pre-CRT to 2553 ± 1692 post-CRT (P = .017). Furthermore, no significant changes were observed pre- to post-CRT with regard to the additional PA assessments. CONCLUSIONS: Our patients exhibited a sedentary lifestyle pre- and post-CRT. These findings underscore the need for a cardiac rehabilitation program that encourages post-CRT patients to decrease sedentary time.

Safety and efficacy of AAIR pacing in selected patients with sick sinus syndrome.

BACKGROUND: The DANPACE study suggested implanting dual-pacing dual-sensing dual-response rate-adaptive (DDDR) pacemakers in patients with sick sinus syndrome, even though 90.7% of their atrial-pacing atrial-sensing inhibited-response rate-adaptive (AAIR) group did not require upgrade. Most centers implant DDDR pacemakers due to risk of future atrioventricular (AV) block. Given that AAIR pacemakers are less expensive, have one less lead with potentially one less point of complication, we question whether DDDR pacemakers are superior to AAIR pacemakers. We aim to describe long-term outcomes of AAIR implants. METHODS: Patients presenting to the Grey Nuns Hospital in Edmonton, Canada from 1990 to 2012 with sick sinus syndrome without AV block had AAIR pacemakers implanted. Outcomes that were measured over the follow-up time included need for ventricular lead reoperation, incidence of AV block and incidence of sudden cardiac death from AV block. RESULTS: During this period, 330 patients presented with sick sinus syndrome. Eighty-seven (26.4%) patients met criteria for and received AAIR pacemakers. Seventy-eight (91.8%) did not require upgrade over mean follow-up of 10.6 ±â€Š0.6 years. Amongst this group, 31 patients (39.7%) were alive, whereas 47 (60.3%) were deceased at end of follow-up due to other comorbidities. No sudden deaths were attributable to AV block. Only 7 patients (8.2%) required ventricular lead reoperation: 2 (2.4%) presented urgently with symptomatic AV block; 3 (3.5%) had atrial fibrillation requiring beta-blockade; 1 (1.2%) had atrial lead dislodgment; and 1 (1.2%) was electively upgraded at battery end-of-life. CONCLUSIONS: This study looks at safety of AAIR pacemakers with only 2.4% of patients developing AV block requiring urgent upgrade. Approximately 91.8% of patients remained with their original AAIR pacemakers (mean follow-up 10.6 vs 5.4 years in DANPACE). Our findings are similar to the DANPACE study but our conclusions are different as we believe AAIR pacing should be considered for selected patients with sick sinus syndrome without AV block.

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.

Proportion of patients followed in a specialized heart failure clinic needing an implantable cardioverter defibrillator as determined by applying different trial eligibility criteria.

Numerous trials have demonstrated survival benefits using implantable cardioverter defibrillators (ICDs) for primary prevention in selected patients with left ventricular (LV) systolic dysfunction. However, eligibility criteria differed across these trials. Without a risk stratification scheme that clearly identifies those who will benefit, there remains debate about which patients with heart failure (HF) should receive ICDs for primary prevention. To explore the implications of applying different eligibility criteria, this study evaluated all patients seen in a specialized HF clinic from August 2003 to January 2004. Of the 309 consecutive patients in the cohort, 46 were excluded because their HF complicated recent myocardial infarcts (n = 3); their LV ejection fractions were not measured (n = 9); or their HF was due to valvular disease, myocarditis, or peripartum cardiomyopathy (n = 34). The Multicenter Automatic Defibrillator Implantation Trial-II criteria were met by 85 patients (32%), and 134 patients (51%) met the Sudden Cardiac Death in Heart Failure Trial criteria. Even allocation decisions based on randomized trial evidence can have vastly different resource implications depending on which trial is chosen. Thus, the development and validation of a risk stratification scheme to identify those patients most likely to benefit from ICDs for primary prophylaxis should be a research priority.

Pulmonary edema post-cardioversion: a potential calcium signalling problem.

The present report describes an unusual case of pulmonary edema after adenosine cardioversion of a supraventricular tachycardia. Despite a structurally normal heart, a 52-year-old woman presented with pulmonary edema on two separate occasions, having had her atrioventricular nodal re-entrant tachycardia terminated with 12 mg of intravenous adenosine. A third similar episode of tachycardia that was terminated with verapamil was not complicated by pulmonary edema.

Short- and long-term outcomes in children undergoing radiofrequency catheter ablation before their second birthday.

BACKGROUND: Tachyarrhythmias can cause substantial morbidity and mortality in infants and very young children. Our objective was to assess early and late outcomes in children undergoing radiofrequency catheter ablation before their second birthday. METHODS: This is a retrospective review of medical records from 1995 till 2009 at a single institution with a large referral base. RESULTS: Thirty-four children younger than 2 years of age were brought to the electrophysiology laboratory for catheter ablation for tachyarrhythmia. Radiofrequency ablation (42 procedures) was performed in 31 children (mean weight, 7.4 kg; range, 2.6-12.3 kg). Tachyarrhythmias were atrioventricular re-entry tachycardia (19), ectopic or multifocal atrial tachycardia (6), atrial flutter (1), ventricular tachycardia (3), and congenital junctional ectopic tachycardia (2). Seventeen children presented with tachycardia-induced cardiomyopathy and heart failure. Three patients required extracorporeal life support prior to the procedure. Radiofrequency catheter ablation was successful in 74% of these very young children vs 91% in a comparison group of children older than 2 years (n = 447). Among patients with initially successful ablations, there was no tachyarrhythmia recurrence during medium- to long-term follow-up (1.4-15.0 years; mean, 7.3 years). Major complications occurred in 4 very young children. Eight of 11 patients in whom ablation failed or could not be done required another form of continued aggressive treatment. CONCLUSION: Catheter ablation is indicated and successful in critically ill infants with life-threatening tachyarrhythmia refractory to medical therapy. Initially successful procedures are associated with excellent long-term outcomes, but significant complication rates require that such procedures be reserved for carefully selected patients and performed by highly skilled staff.

Postpacemaker implant pericarditis: incidence and outcomes with active-fixation leads.

Pericarditis has been noted as a potential complication of pacemaker implantation. This study evaluated the risk of developing pericarditis following pacemaker implantation with active-fixation atrial leads. Included were 1,021 consecutive patients (mean age 73.4+/-0.4 years, range 16-101 years; 45.2% women) undergoing new pacemaker system implantation between 1991 and 1999 who were reviewed for the complication of pericarditis. The incidence and outcomes of postimplantation pericarditis in patients receiving active-fixation atrial leads were compared to those not receiving these leads. Of 79 patients who received active-fixation atrial leads, 4 (5%) developed pericarditis postpacemaker implantation. Of 942 patients with passive-fixation atrial leads or no atrial lead (i.e., a ventricular lead only), none developed pericarditis postoperatively (P < 0.001). Of patients receiving active-fixation ventricular leads only (n = 97), none developed pericarditis. No complications were apparent at the time of implantation in patients who developed pericarditis. Pleuritic chest pain developed between 1 and 28 hours postoperatively. Three patients had pericardial rubs without clinical or echocardiographic evidence of tamponade. They were treated conservatively with acetylsalicylic acid or ibuprofen and their symptoms resolved without sequelae in 1-8 days. One patient (without pericardial rub) died due to cardiac tamponade on postoperative day 6. Postmortem examination revealed hemorrhagic pericarditis with no gross evidence of lead perforation. Pericarditis complicates pacemaker implantation in significantly more patients who receive active-fixation atrial leads. It may be precipitated byperforation of the atrial lead screw through the thin atrial wall. Patients developing postoperative pericarditis should befollowed closely due to the risk of cardiac tamponade.

Automatic sensor algorithms expedite pacemaker follow-ups.

OBJECTIVE: Automatic algorithms can be used to optimize settings and reduce the duration of pacemaker (PM) clinical follow-up. METHODS: This study prospectively evaluated 87 patients (74.2 +/- 10.7 years old, 52% men) who received PM with the Autoslope algorithm. Patients randomized to the manual group (group M, n = 43) performed a walk test and used sensor-indicated rate histograms to adjust the sensor, while in the automatic group (group A, n = 44) the sensor was automatically adjusted by the Autoslope. The patients were followed for 6 months. Follow-up time required for device interrogation and optimal sensor set-up, and the number of sensor parameters reprogramming were recorded. Changes in the patients' activity level were also evaluated. RESULTS: Group A required significantly less follow-up time than group M (9.4 +/- 5.7 min vs 13.5 +/- 8.5 min, P = 0.0002). The average number of sensor parameters reprogrammed during visits was significantly lower in group A than M (0.6 +/- 0.9 vs 0.9 +/- 1.3, P = 0.048). Threshold was adjusted 34.4% of the time in the sensor evaluations in group M versus 12.9% in group A (P = 0.0004). Although more patients in group A reported being more active, the changes in patients' activity level did not lead to increasing sensor setup time or number of parameter reprogramming in either group. CONCLUSIONS: Auto sensor adjustment required less time during routine PM clinical follow-up by reducing steps needed for manual sensor threshold adjustment.