The impact of CIEDs with automatic "wireless" remote monitoring on efficiency.

BACKGROUND: A benefit of automatically transmitting or "wireless" CIEDs (W-CIED) is the prompt detection of device malfunction and arrhythmias. We hypothesized that the use of W-CIEDs would improve the efficiency of remote monitoring by decreasing unnecessary CIED remote transmissions because of the automatic detection of abnormalities. OBJECTIVE: To compare the frequency of patient-initiated transmissions in patients with W-CIEDs versus non-wireless CIEDs (NW-CIED) at a single pediatric and congenital heart center. METHODS: Retrospective cohort study of patients with W-CIEDs followed over a 2-year period compared to a similar cohort of patients with NW-CIED. All CIED remote transmissions during were reviewed for indication and outcome. RESULTS: The W-CIED cohort had 87 patients; mean age 20 ± 13 years; NW-CIED cohort had 220 patients; mean age 22 ± (13) years. The mean number of symptomatic patient-initiated transmissions per patient was 0.93 ± 2.65 in the W-CIED cohort versus 0.39 ± 0.64 in the NW-CIED cohort (p ≤ .001). The mean number of asymptomatic patient-initiated transmission sent per patient in the W-CIED cohort was 1.86 ± 2.59 versus 0.81 ± 1.41 in the NW-CIED cohort (p ≤ .0001). Type of device, age, and presence of congenital heart disease were not significantly associated with the incidence of patient-initiated remote monitoring transmissions. CONCLUSIONS: The frequency of patient-initiated transmission was higher in the W-CIED cohort, contradictory to the study hypothesis. This may reflect a lack of patient understanding of the benefit or functionality of W-CIEDs and may be mitigated by education to both providers and patients.

Acute outcomes of three-dimensional mapping for fluoroscopy reduction in paediatric catheter ablation for supraventricular tachycardia.

BACKGROUND: Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study. METHODS: Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications. RESULTS: In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01). CONCLUSIONS: In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.

Frequency of CIED remote monitoring: A quality improvement follow-up study.

BACKGROUND: Based on the findings of a prior study of CIED (Cardiac Implantable Electrical Device) remote monitoring (RM) frequency at the same center, the University of Michigan Congenital Heart Center (UMCHC) instituted a quality improvement (QI) change to reduce the frequency of routine CIED RM from every 2 months to every 3 months. The objective of this study is to determine the impact of this QI initiative to reduce workload without compromising patient care. METHODS: This is a single-center, retrospective cohort study of all UMCHC patients with CIEDs followed via Medtronic CareLink CIED remote monitoring system from July 2015 to June 2017, after the QI change in 2014. The primary outcome was success of transition to new monitoring schedule. Secondary outcomes included complications, incidence of actionable events (AES), patient compliance, and change in workload. Outcomes were compared to the prior study. RESULTS: There were 325 patients (mean age was 24  ±  14 years) included, of who 293 (90%) completely transitioned to the new RM schedule. During the study period, 96 transmissions included AES (4% of total), of which 50 (52%) were asymptomatic and discovered on routine monitoring. No patient experienced a complication attributable to decreased RM frequency. The mean number of interrogations decreased by 1.6 per patient over the 2-year period compared to prior study. CONCLUSIONS: This study demonstrated successful implementation of a QI initiative to reduce CIED monitoring frequency at a single center with no patient adverse events. The intervention reduced workload and potentially improved patient compliance with routine RM.

Variation in Pediatric Post-Ablation Care: A Survey of the Pediatric and Congenital Electrophysiology Society (PACES).

Although catheter ablation is a standard treatment for pediatric arrhythmias, there are no consensus guidelines for follow-up care. This study describes the variation in post-ablation practices identified through a survey of the pediatric and congenital electrophysiology society (PACES). Pediatric and congenital electrophysiology society members were invited to participate in an online survey of post-ablation practices in September 2014. Survey questions targeted routine post-ablation practices for three common arrhythmia substrates: atrioventricular nodal reentry tachycardia, concealed accessory pathways (AP), and manifest APs. Significant practice variation was defined as <90% concordance among respondents. There were 70 respondents from 67 centers, 29 (41%) in practice for <10 years. Uniform practices included aspirin after left side ablation by 65 (93%), immediate post-procedure ECG by 63 (90%), and performance of outpatient follow-up in 69 (99%) including ECG in 97-100% depending on substrate. The majority, 57 (81%), have standardized follow-up independent of substrate. Post-procedural observation is highly variable, with 25 (36%) discharging patients on the day of ablation, 22 (33%) observing patients in hospital overnight, and 21 (30%) basing hospitalization on pre-defined criteria. Immediate post-procedure echo is performed after all ablations in only 16 (23%). Discharge from outpatient care occurs at a median time of 12 months for each arrhythmia substrate. Common post-ablation practices are evident among pediatric electrophysiologists. However, they report significant variation in post-procedure monitoring practices and testing. The rationale for these variances, and their impact on costs and outcomes, should be defined.

Nadolol for Treatment of Supraventricular Tachycardia in Infants and Young Children.

Supraventricular tachycardia (SVT) is a common infant arrhythmia, for which beta-blockers are frequently chosen as therapy. Propranolol is a common choice though it is dosed every 6-8 h. We reviewed the clinical results of treating infant SVT with an extemporaneous preparation of nadolol. Retrospective cohort study of patients under 2 years old receiving nadolol for SVT at a single center. Patients were ascertained by patient and pharmacy databases. Twenty-eight infants received nadolol, of whom 25 had regular narrow complex tachycardia, 2 atrial flutter, and 1 focal atrial tachycardia. Patient age at initiation was a median 54 days (range 10-720). The final dose was 1 mg/kg/day in 22/28 patients (range 0.5-2). Once-daily dosing was used in 20 patients (71.4%); dosing was BID in 7, TID in 1. Among regular narrow complex tachycardia patients, 18/25 received nadolol monotherapy and 7 required additional agents; flecainide in 6, digoxin in 1. The median age of tachyarrhythmia onset was 18 days (range 1-180) with a median age of nadolol initiation of 30 days (range 11-390). Of the 20 regular narrow complex tachycardia patients initiated on nadolol monotherapy, 85% had no recurrences as of 1-year follow-up. Side effects were suspected in 3 of 28 (10.7%), including wheezing (n = 1, 3.5%), irritability and diarrhea (n = 1, 3.5%), and bradycardia (n = 1, 3.5%). Oral nadolol suspension was a successful treatment for SVT in 85% of patients with minimal adverse effects. Single daily dosing was used in the majority of patients.

Out of many, one: integrating data in the paediatric cardiovascular environment.

Large volumes of data and multiple computing platforms are now universal components of paediatric cardiovascular medicine, but are in a constant state of evolution. Often, multiple sets of related data reside in disconnected "silos", resulting in clinical, administrative, and research activities that may be duplicative, inefficient, and at times inaccurate. Comprehensive and integrated data solutions are needed to facilitate these activities across congenital heart centres. We describe methodology, key considerations, successful use cases, and lessons learnt in developing an integrated data platform across our congenital heart centre.

Implantable Cardioverter Defibrillator Outcomes in Pediatric and Congenital Heart Disease: Time to System Revision.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) are intended to prevent sudden cardiac death yet also impose a risk of morbidity. This study describes the outcomes of ICDs in a pediatric and congenital heart disease (CHD) population from a single center. METHODS: Retrospective cohort study of all patients with an ICD followed at the University of Michigan Congenital Heart Center from 2005-2013. The primary outcome was ICD system revision for any reason excluding routine generator change for battery depletion. RESULTS: There were 191 ICD systems in 131 patients, including 57 with CHD, 24 with hypertrophic cardiomyopathy, and 45 with structurally normal hearts. Median age was 16 years at initial implant. Total follow-up was 850 patient-years; median 4.9 years/patient. There were 43 (33%) patients who required 60 ICD revisions; 70 revisions/1,000 patient-years of follow-up. Revisions included 25 lead extractions with replacement, 21 lead additions, five lead repositions, and four full system revisions. Kaplan-Meier (K-M) median time to appropriate shock was similar to the median time to system revision. K-M time to system revision was significantly affected by recalled lead performance. CONCLUSIONS: The need for ICD system revision is high in this pediatric and CHD population and occurs at a rate similar to the rate of receiving appropriate therapy. These results highlight the need for judicious implant criteria and improved device longevity.

The Impact of Rapid Handpump Repairs on Diarrhea Morbidity in Children: Cross-Sectional Study in Kwale County, Kenya.

BACKGROUND: Handpumps are used by millions of people as their main source of water. Although handpumps represent only a basic form of water provision, there have been continuous efforts to improve the performance of these systems as they are likely to remain in use for many years to come. The introduction of a professional maintenance service in southern Kenya has shown an order of magnitude improvement in operational performance over community-based management, with 90% of handpump faults repaired within 3 days of being reported. One driver behind these efforts is the assumption that a more reliable water supply will lead to a reduction in water-related disease. However, it is not clear if operational improvements lead to health gains. Despite limited empirical evidence, some modeling studies suggest that even short periods of drinking contaminated water can lead to disproportionate negative health impacts. OBJECTIVE: The aim of this study was to assess whether the improvements in operational performance from the rapid professional maintenance of rural handpumps lead to improved household health outcomes. METHODS: From a sample of households using handpumps as their primary water source in Kwale County, Kenya, we measured the 2-week prevalence of World Health Organization-defined diarrhea in children, reported by the adult respondent for each household. We compared the rates before and after a period during which the households' handpumps were being professionally maintained. We then conducted a cross-sectional analysis, fitting logistic regression models with reported diarrhea as the dependent variable and speed of repair as the independent exposure of interest, adjusting for household socioeconomic characteristics; dwelling construction; and Water, Sanitation, and Hygiene (WASH)-related factors. We fitted an additional model to examine select interactions between covariates. RESULTS: Reported diarrhea in children was lower in households whose pumps had been repaired within 24 hours (adjusted odds ratio 0.35, 95% CI 0.24-0.51). This effect was robust to the inclusion of multiple categories of covariates. No reduction was seen in households whose pump repairs took more than 24 hours. Analysis of interaction terms showed that certain interventions associated with improved WASH outcomes were only associated with reductions in diarrhea in conjunction with socioeconomic improvements. CONCLUSIONS: Only pump repairs consistently made within 24 hours of failure led to a reduction in diarrhea in the children of families using handpumps. While the efficacy of reduction in diarrhea is substantial, the operational challenges of guaranteeing same-day repairs limits the effectiveness of even best-in-class pump maintenance. Maintenance regimes that cannot bring handpump downtimes close to zero will struggle to generate health benefits. Other factors that reduce diarrhea prevalence have limited effect in isolation, suggesting that WASH interventions will be more effective when undertaken as part of more holistic poverty-reduction efforts.

Cardiac Resynchronization Therapy for Patients With Mild to Moderately Reduced Ejection Fraction and Left Bundle Branch Block.

BACKGROUND: It is unknown whether cardiac resynchronization therapy (CRT) would improve or halt the progression of heart failure (HF) in patients with mild to moderately reduced ejection fraction (HFmmrEF) and left bundle branch block (LBBB). OBJECTIVE: This study aimed to investigate the outcomes of CRT in patients with HFmmrEF and left ventricular conduction delay. METHODS: A prospective, randomized clinical trial sponsored by the National Heart, Lung, and Blood Institute included 76 patients who met the study inclusion criteria (left ventricular ejection fraction [LVEF] of 36%-50% and LBBB). Patients received CRT-pacemaker and were randomized to CRT-OFF (right ventricular pacing 40 beats/min) or CRT-ON (biventricular pacing 60-150 beats/min). At a 6-month follow-up, pacing programming was changed to the opposite settings. New York Heart Association class, N-terminal pro-brain natriuretic peptide levels, and echocardiographic variables were collected at baseline, 6 months, and 12 months. The primary study end point was the left ventricular end-systolic volume (LVESV) change from baseline, and the primary randomized comparison was the comparison of 6-month to 12-month changes between randomized groups. RESULTS: The mean age of the patients was 68.4 ± 9.8 years (male, 71%). Baseline characteristics were similar between the 2 randomized groups (all P > .05). In patients randomized to CRT-OFF first, then CRT-ON, LVESV was reduced from baseline only after CRT-ON (baseline, 116.1 ± 36.5 mL; CRT-ON, 87.6 ± 26.0 mL; P < .0001). The randomized analysis of LVEF showed a significantly better change from 6 to 12 months in the OFF-ON group (P = .003). LVEF was improved by CRT (baseline, 41.3% ±.7%; CRT-ON, 46.0% ± 8.0%; P = .002). In patients randomized to CRT-ON first, then CRT-OFF, LVESV was reduced after both CRT-ON and CRT-OFF (baseline, 109.8 ± 23.5 mL; CRT-ON, 91.7 ± 30.5 mL [P < .0001]; CRT-OFF, 99.3 ± 28.9 mL [P = .012]). However, the LVESV reduction effect became smaller between CRT-ON and CRT-OFF (P = .027). LVEF improved after both CRT-ON and CRT-OFF (baseline, 42.7% ± 4.3%; CRT-ON, 48.5% ± 8.6% [P < .001]; CRT-OFF, 45.9% ± 7.7% [P = .025]). CONCLUSION: CRT for patients with HFmmrEF significantly improves LVEF and ventricular remodeling after 6 months of CRT. The study provides novel evidence that early CRT benefits patients with HFmmrEF with LBBB.

Utility of intrathoracic impedance monitoring in pediatric and congenital heart disease.

BACKGROUND: The utility of cardiac device-based intrathoracic monitoring (OptiVol, Medtronic Inc., Minneapolis, MN, USA) for congestive heart failure (CHF) exacerbation has not been evaluated in pediatric or congenital heart disease patients. METHODS: This was a retrospective study of all patients at a single center with an endocardial OptiVol capable device. OptiVol index values were collected in 2-week bins from January 2007 to December 2010. The clinical outcomes were CHF exacerbation defined as hospitalization or medication change for CHF and device-treated ventricular arrhythmia based on remote or in-office device interrogation. Clinical and OptiVol data were collected by separate investigators blinded to the other parameter. OptiVol data were correlated to the clinical outcomes to determine sensitivity and predictability for multiple threshold values in the entire cohort and pediatric and congenital subgroups. RESULTS: Forty-seven patients were included. A total of 1,106 months of OptiVol data were collected. Median age of the cohort was 18 years (range 6-58 years). There were 23 pediatric, median age 13 years (range 6-16), at device implant, and 18 patients, median age 31 years (range 13-58), considered at risk for heart failure at implant. There were three heart failure exacerbations and 17 treated ventricular arrhythmias. The study population-specific positive predictive value (PPV) of OptiVol was low (sensitivity 33% and PPV ≤4.4%) for both CHF exacerbation and arrhythmias in all analyzed groups. CONCLUSIONS: The sensitivity and positive predictive value of intrathoracic impedance monitoring was low in this population of adult congenital and pediatric patients. Recent improvements to the OptiVol algorithm may decrease these deficiencies.

Verapamil in infants: an exaggerated fear?

The use of intravenous verapamil for tachyarrhythmia in infants is widely considered contraindicated due to the perceived risk of hemodynamic collapse after administration. This article reviews the relatively limited evidence that led to this well-known contraindication and highlights the interesting process by which medical practice may evolve in the absence of persuasive science.

Pattern of recovery for transient complete heart block after open heart surgery for congenital heart disease: duration alone predicts risk of late complete heart block.

Transient complete heart block (TCHB) is defined as complete interruption of atrioventricular conduction (AVC) after cardiac surgery followed by return of conduction. This study aimed to assess the risk for the development of late complete heart block (LCHB) after recovery of TCHB and to examine the electrocardiographic and electrophysiologic properties of the AVC system after TCHB. Of the 44 patients in this study who experienced TCHB, 37 recovered completely. Seven patients progressed from TCHB to intermittent CHB or LCHB requiring pacemaker implantation. Preoperative, early postoperative, and late postoperative electrocardiograms as well as postoperative atrial stimulation were obtained. The results showed that the median duration of TCHB was 5 days in the TCHB group compared with 9 days in the LCHB group (p = 0.01). All 37 subjects with TCHB recovered AVC within 12 days, but only two with LCHB did so (p = 0.02). The risk of LCHB for the patients with 7 days of postoperative TCHB or longer was 13 times greater than for the patients with fewer than 7 days of TCHB (p = 0.01). The median late postoperative PR interval was slightly but significantly longer in the LCHB group than in the TCHB group (p = 0.02). In contrast, the electrophysiologic properties between the two groups did not differ significantly. From those findings, we concluded that delayed recovery of AVC after surgical TCHB (≥7 days), but not electrophysiologic properties of recovered AVC assessed early in the postoperative period strongly, predicts risk of LCHB. Follow-up evaluation of AVC is particularly indicated for the delayed recovery group.

Implanted defibrillators in young hypertrophic cardiomyopathy patients: a multicenter study.

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease, with an annual risk of sudden cardiac death (SCD) estimated at 1 %. Limited data are available regarding both the risk of SCD in the young HCM population and the use of implantable cardioverter-defibrillators (ICDs). This retrospective study included all patients with HCM who underwent ICD implantation for primary or secondary prevention of SCD before the age of 30 years at five institutions between 1995 and 2009. There were 99 devices implanted in 73 patients. Appropriate shocks occurred for 11 % of all the patients. None of the previously identified conventional risk factors for SCD in HCM patients were associated with increased risk of appropriate shocks in the young study cohort. During a median follow-up period of 2.4 years, inappropriate shocks occurred for 22 % of the patients. Older age at implant was associated with a decreased risk of inappropriate shock. Those who underwent implantation in the earlier decade had a higher incidence of inappropriate shocks. Late complications including lead fracture or dislodgement, generator malfunction, and infection occurred for 32 % of the patients. Three patients died (4 %), one of whom had an arrhythmic sudden death. A greater proportion of primary prevention implantations was performed for patients from the latter decade. Over time, ICD use in young HCM patients has become increasingly primary prevention oriented. Shock rates mirror those reported in adult series, and there is a substantial incidence of device complications.

Nurse Practitioner Delivered Virtual Care in a Pediatric Specialty Clinic.

INTRODUCTION: Virtual care in pediatric specialty practice has become widely used to increase access to care, one in which nurse practitioners (NPs) can play a vital role. We sought to evaluate the outcomes of virtual care provided by pediatric cardiology and electrophysiology (EP) NPs for pediatric and congenital heart disease patients. METHOD: Retrospective review of all virtual care visits performed by pediatric EP NPs between October 2019 and October 2021 at a single tertiary care center. RESULTS: NPs delivered virtual care for 287 pediatric EP evaluations for 276 patients; 132 (45%) independently, with the remaining 155 collaborating with an electrophysiologist as a shared visit. The mean age was 15.2 ± 8.9 years. DISCUSSION: NPs performed a significant subset of these visits independently and were a vital part of all visits in this study. The role of the NP in specialty pediatric virtual care should continue to be supported and advanced.

Novel ryanodine receptor 2 mutation associated with a severe phenotype of catecholaminergic polymorphic ventricular tachycardia.

An adolescent girl with a history of anxiety associated seizure-like episodes was ultimately diagnosed with catecholaminergic polymorphic ventricular tachycardia. She tested positive for a novel mutation of the ryanodine receptor. The report underscores how genetic arrhythmia syndromes may be mistaken for neurologic disorders.

Cryoablation therapy for atrioventricular nodal reentrant tachycardia in children: a multicenter experience of efficacy.

Atrioventricular nodal reentrant tachycardia (AVNRT), a common tachycardia in children, is routinely treated by catheter ablation using radiofrequency or cryothermal energy. Acute success rates of 95-97 % are reported for cryoablation, similar to those achieved with radiofrequency ablation (RFA). However, early studies reported higher recurrence rates after cryoablation for treatment of AVNRT than those reported for RFA. This study evaluated the success and recurrence rates for cryoablation in a current cohort of pediatric patients across several institutions. Patients 21 years old or younger with AVNRT who underwent cryoablation at five participating centers between 2004 and 2009 were retrospectively reviewed. Patient demographics and procedural data were extracted from patient records and analyzed. A total of 434 patients with AVNRT who underwent cryoablation were identified. Cryoablation was used as the exclusive ablation method for 379 patients. For 97 % (368/379) of these patients, cryoablation was acutely successful. A higher acute success rate was found with the 6-mm-tip catheter (99 %) than with the 4-mm-tip catheter (91 %) (p < 0.01). Recurrence was experienced by 7.3 % of the patients. Recurrence was more likely for those treated with the 4-mm-tip catheter (6/42, 14 %) than for those who had the larger catheters (12/204, 6 %) No patient experienced permanent heart block. Success and recurrence rates for this cohort of patients were similar to those reported for RFA used to treat AVNRT in pediatric patients. The findings show a higher success rate and a lower recurrence rate after cryoablation with a 6-mm-tip catheter than after use of the 4-mm-tip catheter, with an associated excellent safety profile.

Clinical characteristics and long-term outcomes of catheter ablation in young adults with atrial fibrillation.

PURPOSE: We aim to describe the long-term safety and efficacy of catheter ablation (CA) in young patients (<30 years) with atrial fibrillation (AF). METHODS: This was a retrospective study of patients aged 18-30 who underwent CA for AF, and clinical characteristics and long-term outcomes are reported. Survival analyses were performed between the study group and a propensity-matched older cohort (>30 years, mean age: 58±10 years). RESULTS: From January 2000 to January 2019, a 1st CA (radiofrequency energy n=72, cryoballoon n=10), was performed in 82 patients (mean age 26±4 years, paroxysmal n=61, persistent n=14, longstanding persistent n=7), among 6336 consecutive patients with AF. During a follow-up of 5±5 years, 56% and 30% of the patients with paroxysmal and non-paroxysmal AF were arrhythmia free without antiarrhythmic drug (AAD) therapy after a single CA (P=0.02). After 1.5±0.8 CA procedures, 76% and 75% of the patients with paroxysmal AF and non-paroxysmal AF were arrhythmia free without AADs (P=0.54). Compared to a propensity-matched group of older patients, young patients were as likely to remain in sinus rhythm after CA (P=0.47), however after fewer repeat CAs (1.5±0.8 vs 1.9±0.9, P<0.009). There were no long-term adverse outcomes associated with CA. CONCLUSIONS: CA is a safe and effective treatment of AF in young patients with comparable outcomes to the older patients, however after fewer procedures.

Impact and Modifiers of Ventricular Pacing in Patients With Single Ventricle Circulation.

BACKGROUND: Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPMv) may be associated with additional adverse long-term outcomes. OBJECTIVES: The goal of this study was to quantify the attributable risk of PPMv in patients with SV, and to identify modifiable risk factors. METHODS: This international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPMv. Enrollment was at implantation. Controls were matched 1:1 to PPMv subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death. RESULTS: In total, 236 PPMv subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPMv cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPMv was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPMv population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation. CONCLUSIONS: PPMv in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPMv cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors.

No increased bleeding events with continuation of oral anticoagulation therapy for patients undergoing cardiac device procedure.

BACKGROUND: Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high-risk patients undergoing device-related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device-related procedure. METHODS AND RESULTS: We retrospectively studied 766 consecutive patients taking warfarin long term who underwent device-related procedures. Patients were grouped by treatment: discontinued warfarin (-warfarin, n = 243), no interruption of warfarin (+warfarin, n = 324), and discontinued warfarin with heparin bridging (+heparin, n = 199). The study primary endpoint was systemic bleeding or formation of moderate or severe pocket hematoma within 30 days of the procedure. Thirty-one (4%) patients had bleeding events, including pocket hematoma in 29 patients. The bleeding events occurred more often for +heparin (7.0%) than -warfarin (2.1%) or +warfarin (3.7%, P = 0.029). For +warfarin group, INR of 2.0-2.5 at time of procedure did not increase bleeding risk compared with INR less than 1.5 (3.7% vs 3.4%; P = 0.72), but INR greater than 2.5 increased the bleeding risk (10.0% vs 3.4%; P = 0.029). Concomitant aspirin use with warfarin significantly increased bleeding risk than warfarin alone (5.6% vs 1.4%, P = 0.02). Median length of hospitalization was significantly shorter for +warfarin than +heparin (1 vs 6 days; P < 0.001). CONCLUSION: Continuation of oral anticoagulation therapy with an INR level of <2.5 does not impose increased risk of bleeding for device-related procedures, although precaution is necessary to avoid supratherapeutic anticoagulation levels.

Multicenter study of the effectiveness of implantable cardioverter defibrillators in children and young adults with heart disease.

Implantable cardioverter defibrillators (ICDs) are being used with increasing frequency in children and young adults. Our aim was to examine the appropriateness and frequency of ICD discharges in children and young adults, to compare the effectiveness of ICDs when placed for primary or secondary prevention, and to provide time-dependent analysis of ICD discharges. Data were collected from seven institutions on 210 patients <30 years of age who underwent ICD implantation from October 1992 to January 2007. Median age at implant was 15.4 years with a follow-up average of 3.3 years. Heart disease was categorized as electrical (n = 90, 42%), cardiomyopathic (n = 62, 30%), or congenital heart disease (n = 58, 28%). ICDs are increasingly placed for primary prevention. There are increased appropriate ICD discharges for ICDs placed for secondary prevention (52%) versus primary prevention (14%) at 5 years. There is no difference in the risk of inappropriate discharges between primary and secondary prevention indications. There is an increased risk for inappropriate therapy in the congenital heart disease population. An increasing number of ICDs are being placed for primary prevention in young patients, a marked shift in practice during the last two decades. The benefits of ICDs remain greater in secondary than in primary-prevention patients. In both groups, approximately 25% of patients received inappropriate discharges within 5 years of implant. Patients with congenital heart disease are the most affected by inappropriate discharges.