Implantable Defibrillator Therapy Research Articles

Rate and impact on patient outcome and healthcare utilization of complications requiring surgical revision: Subcutaneous versus transvenous implantable defibrillator therapy

Comparison data on management of device-related complications and their impact on patient outcome and healthcare utilization between subcutaneous implantable cardioverter-defibrillator (S-ICD) and transvenous ICD (TV-ICD) are lacking. We designed this prospective, multicentre, observational registry to compare the rate, nature, and impact of long-term device-related complications requiring surgical revision on patient outcome and healthcare utilization between patients undergoing S-ICD or TV-ICD implantation. A total of 1099 consecutive patients who underwent S-ICD or TV-ICD implantation were enrolled. Propensity matching for baseline characteristics yielded 169 matched pairs. Rate, nature, management, and impact on patient outcome of device-related complications were analyzed and compared between two groups. During a mean follow-up of 30 months, device-related complications requiring surgical revision were observed in 20 patients: 3 in S-ICD group (1.8%) and 17 in TV-ICD group (10.1%; p = .002). Compared with TV-ICD patients, S-ICD patients showed a significantly lower risk of lead-related complications (0% vs. 5.9%; p = .002) and a similar risk of pocket-related complications (0.6 vs. 2.4; p = .215) and device infection (0.6% vs. 1.2%; p = 1.000). Complications observed in S-ICD patients resulted in a significantly lower number of complications-related rehospitalizations (median 0 vs. 1; p = .013) and additional hospital treatment days (1.0 ± 1.0 vs. 6.5 ± 4.4 days; p = .048) compared with TV-ICD patients. Compared with TV-ICD, S-ICD is associated with a lower risk of complications, mainly due to a lower risk of lead-related complications. The management of S-ICD complications requires fewer and shorter rehospitalizations.

Progressive increase in activation delay during premature stimulation is related to ventricular fibrillation in Brugada syndrome.

The local conduction delay has been deemed to play an important role in the perpetuation of ventricular fibrillation (VF) in Brugada syndrome (BrS). We evaluated the relationship between the activation delay during programmed stimulation and cardiac events in BrS patients. This study included 47 consecutive BrS patients who underwent an electrophysiological study and received implantable cardiac defibrillator therapy. We divided the patients into two groups based on whether they had developed VF (11 patients) or not (36 patients) during the follow-up period of 89 ± 53 months. The activation delay was assessed using the interval between the stimulus and the QRS onset during programmed stimulation. The mean increase in delay (MID) was used to characterize the conduction curves. The MID at the right ventricular outflow tract (RVOT) was significantly greater in patients with VF (4.5 ± 1.2 ms) than in those without VF (2.2 ± 0.9 ms) (p < .001). A receiver operating characteristics curve analysis indicated that the optimal cut-off point for discriminating VF occurrence was 3.3 with 88.9% sensitivity and 91.3% specificity. Furthermore, patients with an MID at the RVOT ≥ 3.3 ms showed significantly higher rates of VF recurrence than those with an MID at the RVOT < 3.3 ms (p < .001). The clinical characteristics, including the signal-averaged electrocardiogram measurement and VF inducibility were similar between the two groups. A prolonged MID at the RVOT was associated with VF and maybe an additional electrophysiological risk factor for VF in BrS patients.

Renal Denervation for the Management of Refractory Ventricular Arrhythmias: ASystematicReview.

The authors performed a systematic review and meta-analysis to determine the efficacy of renal denervation (RDN) in patients with refractory ventricular arrhythmias (VA) or electrical storm (ES). Although catheter ablation is efficacious for the treatment of structural heart disease ventricular tachycardia (VT), there are proportion of patients who have refractory VT despite multiple procedures. In this setting, novel adjunctive therapies such as renal denervation have been performed. A systematic review of published data was performed. Studies that evaluated patients undergoing RDN for VA or ES were included. Outcome measures of VA, sudden cardiac death, ES, or device therapy were required. Case reports, editorials, and conference presentations were excluded. Random effects meta-analysis was conducted to explore change or final mean values in the study outcomes. A total of 328 articles were identified by the literature search. Seven studies met the eligibility criteria and were included in the systematic review, with a total of 121 pooled patients. The weighted mean age was 63.8 ± 13.1 years, ejection fraction 30.5 ± 10.3%, 76% were men, 99% were on a beta blocker, 79% were on amiodarone, 46% had previously undergone catheter ablation, and 8.3% had previously undergone cardiac sympathetic denervation. Meta-analysis demonstrated a significant effect of RDN in reducing implantable cardiac defibrillator therapies, with a standardized mean difference (SMD) of-3.11 (p<0.001). RDN also reduced the number of VA episodes (SMD-2.13; p<0.001), antitachycardia pacing episodes (SMD-2.82; p=0.002), and shocks (SMD-2.82; p=0.002). RDN is an effective treatment for refractory VAs and ES, although randomized data are lacking.

J point elevation in high precordial leads associated with risk of ventricular fibrillation.

IntroductionThe significance of high precordial electrocardiograms in idiopathic ventricular fibrillation (IVF) is unknown.MethodThis study included 50 consecutive patients (48 men; age, 42 ± 18 years) who had spontaneous ventricular fibrillation not linked to structural heart disease and received implantable cardiac defibrillator therapy. IVF was diagnosed in 35 patients and Brugada syndrome was diagnosed in other 15 patients. Electrocardiograms in high intercostal space were compared between 35 patients with IVF and 105 age‐ and sex‐matched healthy controls (patient: control ratio, 1:3).ResultsThe frequency of J point elevation ≥ 0.1 mV in the 4th intercostal spaces was similar between patients with IVF (14%) and healthy controls (7%). However, the frequency of J point elevation ≥ 0.1 mV in the 3rd intercostal space was higher in patients with IVF (40%) than controls (11%) (p < .01). J point elevation was present only in the 3rd intercostal space but not in the 4th intercostal space in 30% of patients with IVF but only in 6% of controls (p < .01). During follow‐up, the recurrence of ventricular fibrillation was higher in patients with IVF who had J point elevation in the 3rd intercostal space (36%) and Brugada syndrome(40%) than those with IVF who did not have J point elevation in the 3rd intercostal space(11%) (p < .05 for both).ConclusionJ point elevation in the 3rd intercostal space was associated with IVF and recurrences of ventricular fibrillation. Electrocardiogram recordings in the high intercostal space may be useful to identify risk of sudden death.

Risk Factors and Long-Term Survival of Octogenarians and Nonagenarians Undergoing Transvenous Lead Extraction Procedures

Introduction: Transvenous lead extraction (TLE) has become a frequently used tool for the management of complications related to pacemakers, implantable cardiac defibrillators and cardiac resynchronization therapy devices. However, it is still a matter of debate whether the lead extraction procedure is a safe treatment choice in the elderly. Methods: We collected the clinical information from 3,810 patients undergoing TLE in 2 high-volume centers (Poland and Italy) between 2006 and 2017. We tested risk factors, effectiveness, safety and long-term survival in 3 groups of patients: those aged 80–89.99 years, ≥90 years and 30–79.99 years. Results: Lower BMI, lower levels of hemoglobin and more comorbidities characterized the patients, whose ages ranged from 80 to 89.99 years. Those aged ≥90 years most often had single-chamber pacemakers. Octogenarians and nonagenarians were more often undergoing TLE due to infectious indications (57.19 and 74.29 vs. 45.35% in younger individuals). Lead age and the number of leads extracted were comparable in the 3 groups. In octogenarians, leads were more often removed using standard extraction techniques: simple traction and mechanical dilatators, whereas in nonagenarians TLE was more complex. The duration of the procedure was shorter in older patients, while clinical and procedural effectiveness was similar to that in younger individuals. The rate of major complications related to TLE did not differ between octogenarians and younger subjects (2.0 vs. 1.38%, p = ns), and the number of procedure-related risk factors was smaller in older people. Nonagenarians did not develop any major complication related to TLE. Long-term mortality after TLE was similar among octogenarians and nonagenarians (39.67 and 40.00%) but higher than in younger patients (24.41; p < 0.001 and 0.05). Conclusions: Lead extraction procedures appear effective and safe in octogenarians and nonagenarians, comparable to younger individuals. Procedure-related risk in the elderly is not associated with most of the typical risk factors encountered in younger subjects, but only with the higher number of pacemaker, implantable cardiac defibrillator and cardiac resynchronization therapy device procedures before TLE. Long-term survival after TLE was found to be similar among octogenarians and nonagenarians being about 60% at over 3 years of follow-up. Age alone should not be considered a risk factor for the occurrence of major complications or procedure-related death, and therefore it should not prevent candidacy for TLE.

Long-Term Survival After Implantable Cardiac Defibrillator Therapy According to Sex: A Propensity Matched Study.

Background: Whether the sex factor influences the benefit of the implantable cardioverter-defibrillator (ICD) for the prevention of sudden death remains a subject of debate. Using a prospective registry, we sought to analyze the survival and time to first ICD therapy according to sex. Materials and Methods: Retrospective analysis of a prospective cohort of patients undergoing an ICD implant from 2008 to 2019. Data about time to first appropriate therapy, type of therapy administered, and incidence and causes of mortality were collected. Results: Among 756 ICD patients, 150 (19.8%) were women. Women were younger (51 ± 15 years vs. 61 ± 14 years; p < 0.001) and showed a lower rate of ischemic cardiomyopathy (23% vs. 54%; p < 0.001) and atrial fibrillation (12% vs. 19%; p = 0.05). Women had higher left ventricular ejection fraction (39% ± 17% vs. 35% ± 13%) and showed more frequently left bundle branch block (39% vs. 28%, p = 0.027). The rate of primary prevention (68% vs. 59.6%; p = 0.058) and cardiac resynchronization therapy (27% vs. 19%, p = 0.02) were higher in women. After a median follow-up of 46 months (3382 patient-years), the incidence of both the primary combined endpoint of mortality/transplant (20% vs. 29%; logrank = 0.031) and ICD therapies (27% vs. 34%; p = 0.138) were lower in women. According to the propensity score-matching analysis, no differences were observed between both sexes with respect to the incidence of mortality/transplant (24.8% vs. 28.6%; logrank = 0.88), ICD therapies (28% vs. 27%; logrank = 0.17), and main cause of death (heart failure [HF]). Conclusions: The clinical characteristics at the moment of ICD implant are different between sexes. After adjusting them, both sexes equally benefit from the ICD. HF is the main cause of mortality both in men and women.

Long-term outcomes evaluated by device-monitored physical activity in patients with implantable cardiac defibrillator or cardiac resynchronization therapy device

Abstract Background The patients with implantable cardiac defibrillator (ICD) or cardiac resynchronization therapy device (CRT) have high risk of cardiac events, and lower physical activity has been thought to be associated with higher rate of cardiac events. On the other hand, cardiovascular implantable electronic devices can monitor physical activity through a built-in accelerometer. This study aimed to analyze long-term outcomes by device-based monitoring of physical activity in patients with ICD or CRT. Methods We retrospectively reviewed 89 patients with ICD/CRT, (56 males, 66.5 years old; ICD 45, CRT-D 42, CRT-P 2) who survived longer than 6 months after implantation in our institution. We analyzed physical activity by devices at 6th month and divided to 2 groups; In Low activity group (group L; n=38), their physical activity (moving time above 70 steps/min walk level) is less than 2 hours/day, and in Normal activity group (group N; n=51), physical activity is more than 2 hours/day. We evaluated their background characteristics in each group, physical activity at 12th month, and composite outcomes of hospitalization due to worsening of heart failure (HF) and death of any cause. Results Mean follow-up period was 57.4 months (median 40 months). In group L, they had higher age (71.1 y.o. vs. 63.2 y.o.; p=0.0003), higher rate of low EF (76.3% vs. 54.9%; p=0.035), and lower rate of attendance to outpatient cardiac rehabilitation program (10.5% vs 27.5%; p=0.043) compared with group N. 85.7% of patients in group L stayed in low physical activity at 12th month, and 87.8% of patient in group N stayed in normal physical activity. Composite outcomes of HF hospitalization and death occurred significantly higher in group L (Log-rank p&amp;lt;0.0001; 29.0% vs. 5.9% at 1 year, and 68.7% vs. 16.2% at 3 year: Figure 1) than in group N. Each event, HF hospitalization and death of any cause were shown significantly higher in group L (Log-rank p&amp;lt;0.0001). In group L, mortality rate of patients who could improve their physical activity from 6th month to 12th month was significantly lower than patients who stayed in low physical activity (Log-rank p=0.038). Conclusions Lower level of device-monitored physical activity was associated with higher mortality and higher rate of HF hospitalization in patients with ICD or CRT. Most of the patient in lower physical activity could not improve their activity from 6th month to 12th month. Early and continuous intervention is necessary especially for high risk patients such as high age or low EF. Figure 1 Funding Acknowledgement Type of funding source: None

Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip

Abstract Background Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR. Methods We retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction, functional mitral regurgitation grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up. Results 93 patients (68.2±10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-months follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0–17.8 vs 2.7–13.5, p=0.002), sustained VT or ventricular fibrillation (0.9–2.5 vs 0.5–2.9, p=0.012) and ICD antitachycardia therapies (2.5–12.0 vs 0.9–5.0, p=0.033) were observed. Conclusion PMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort. Proportion of patients who presented ven Funding Acknowledgement Type of funding source: None

Improving guideline-mandated care of patients with implantable cardiac defibrillators.

Implantable cardiac defibrillators reduce the risk of sudden cardiac death in selected patients. The value of an implantable cardiac defibrillator declines as the patient's disease progresses. Guidelines suggest that the appropriateness of maintaining implantable cardiac defibrillator therapy be regularly reviewed as part of monitoring of the patient's disease trajectory. It is recommended that implantable cardiac defibrillators are deactivated as patients approach the end of life. Patients with a better understanding of their current state of health and the role that the implantable cardiac defibrillator plays within it are more likely to make informed decisions about the timing of deactivation. A quality improvement project was undertaken on appropriate deactivation of implantable cardiac defibrillators within a large tertiary cardiac centre. This was driven by audit data showing inadequate patient communication and documentation around deactivation. Drivers for change included the introduction of electronic data records, clinical review of comorbid patients approaching elective battery change and an ongoing forum for patient and carer education. Measured outcomes included the number of deactivations performed, evidence of patient discussion and consent, and timing of deactivation of the implantable cardiac defibrillator. There were increased numbers of timely device deactivations undertaken following the interventions with improved documented evidence of patient discussion and consent. The educational forum was received favourably. Focused multidisciplinary interventions can impact favourably on appropriate implantable cardiac defibrillator deactivation and improve patient engagement.

Lower Rates of Heart Failure and All-Cause Hospitalizations During Pulmonary Artery Pressure-Guided Therapy for Ambulatory Heart Failure: One-Year Outcomes From the CardioMEMS Post-Approval Study.

Ambulatory hemodynamic monitoring with an implantable pulmonary artery (PA) sensor is approved for patients with New York Heart Association Class III heart failure (HF) and a prior HF hospitalization (HFH) within 12 months. The objective of this study was to assess the efficacy and safety of PA pressure-guided therapy in routine clinical practice with special focus on subgroups defined by sex, race, and ejection fraction. This multi-center, prospective, open-label, observational, single-arm trial of 1200 patients across 104 centers within the United States with New York Heart Association class III HF and a prior HFH within 12 months evaluated patients undergoing PA pressure sensor implantation between September 1, 2014, and October 11, 2017. The primary efficacy outcome was the difference between rates of adjudicated HFH 1 year after compared with the 1 year before sensor implantation. Safety end points were freedom from device- or system-related complications at 2 years and freedom from pressure sensor failure at 2 years. Mean age for the population was 69 years, 37.7% were women, 17.2% were non-White, and 46.8% had preserved ejection fraction. During the year after sensor implantation, the mean rate of daily pressure transmission was 76±24% and PA pressures declined significantly. The rate of HFH was significantly lower at 1 year compared with the year before implantation (0.54 versus 1.25 events/patient-years, hazard ratio 0.43 [95% CI, 0.39-0.47], P<0.0001). The rate of all-cause hospitalization was also lower following sensor implantation (1.67 versus 2.28 events/patient-years, hazard ratio 0.73 [95% CI, 0.68-0.78], P<0.0001). Results were consistent across subgroups defined by ejection fraction, sex, race, cause of cardiomyopathy, presence/absence of implantable cardiac defibrillator or cardiac resynchronization therapy and ejection fraction. Freedom from device- or system-related complications was 99.6%, and freedom from pressure sensor failure was 99.9% at 1 year. In routine clinical practice as in clinical trials, PA pressure-guided therapy for HF was associated with lower PA pressures, lower rates of HFH and all-cause hospitalization, and low rates of adverse events across a broad range of patients with symptomatic HF and prior HFH. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02279888.

Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip®.

BackgroundLimited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR.MethodsWe retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction (LVEF), functional mitral regurgitation (FMR) grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up.ResultsNinety-three patients (68.2±10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-month follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0±17.8 vs. 2.7±13.5, P=0.002), sustained VT or ventricular fibrillation (0.9±2.5 vs. 0.5±2.9, P=0.012) and ICD antitachycardia therapies (2.5±12.0 vs. 0.9±5.0, P=0.033) were observed.ConclusionsPMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort.

Echocardiographic Predictors of All-Cause Mortality in Patients with Hypertrophic Cardiomyopathy following Pacemaker Implantation.

Objectives To examine the association between the echocardiographic parameters measured as left atrial diameter (LAD) and left ventricular end-diastolic diameter (LVEDD) and long-term risk of all-cause mortality in adults with hypertrophic cardiomyopathy (HCM) following pacemaker implantation. Methods A total of 94 adult patients with HCM who underwent pacemaker implantation from November 2002 to June 2013 in our Arrhythmia Center for symptomatic bradycardia and did not receive an implantable cardiac defibrillator (ICD) or cardiac resynchronization therapy (CRT) during follow-up were retrospectively extracted. Results After careful examination of the medical records, we retrospectively evaluated the clinical characteristics of 74 patients with LAD records (58.1 ± 14.9 years) and 76 patients with LVEDD records (57.6 ± 15.2 years). Based on the receiver-operating characteristic (ROC) curve, the values of LAD = 44 mm and LVEDD = 43 mm were identified to predict the all-cause mortality. In the Kaplan–Meier survival, LAD ≥44 mm and LVEDD ≥43 mm were both significantly associated with all-cause mortality (log-rank test P < 0.05). Cox regression analysis indicated that LAD ≥44 mm (HR 3.580; 95% CI = 1.055–12.148; P=0.041) was an independent predictor of all-cause mortality, while LVEDD ≥43 mm was not significantly associated with all-cause mortality. LVOTO was also significantly associated with all-cause mortality (HR = 0.166; 95% CI = 0.036–0.771; P=0.022). Conclusions In HCM patients with pacemaker implantation, LAD ≥44 mm was an independent predictor of all-cause mortality.

Recovered Left Ventricular Ejection Fraction and Its Prognostic Impacts in Hospitalized Heart Failure Patients with Reduced Ejection Fraction.

It has been recently recognized that recovery of left ventricular ejection fraction (EF), termed "recovered EF", occurs in a proportion of heart failure patients with reduced EF (HFrEF), and is associated with better prognosis. However, the clinical characteristics of "recovered EF" have not been fully examined.Consecutive 567 patients hospitalized due to HFrEF (EF < 40% at 1st assessment at hospital discharge) were enrolled, and EF was re-assessed within half a year in an outpatient setting (2nd assessment). Among these HFrEF patients, 235 remained EF < 40% (reduced, rEF group), 82 changed to EF 40-49% (midrange, mrEF group), and 250 recovered to EF > 50% (preserved, pEF group "recovered EF" ) at the 2nd examination. Age was lower and body mass index and systolic blood pressure were higher in pEF than in rEF. The prevalence of atrial fibrillation (AF) and usage of an implantable cardiac defibrillator and cardiac resynchronization therapy were highest in pEF. Left ventricular end diastolic dimension (LVDd) was the smallest in the pEF group. Multivariable logistic regression analysis revealed that younger age, presence of AF, and lower levels of LVDd were predictors of "recovered EF". Kaplan-Meier analysis found that pEF presented the lowest cardiac event rate (P = 0.003) and all-cause mortality (P = 0.001). In multivariable Cox proportional hazard analyses, pEF (versus rEF) was an independent predictor of both cardiac event rate (HR = 0.668, 95%CI 0.450-0.994, P = 0.046) and all-cause mortality (HR = 0.655, 95%CI 0.459-0.934, P = 0.019).Hospitalized HFrEF patients with recovered EF are associated with younger age, higher presence of AF, and better prognosis.

First Let's Try… Will the Success of New Therapies Paradoxically Challenge Outcomes in Advanced Heart Failure?

First Let's Try… Will the Success of New Therapies Paradoxically Challenge Outcomes in Advanced Heart Failure?

Prognosis and Natural History of Conduction System Disease in Patients Undergoing Coronary Angiography

BackgroundInfranodal conduction abnormalities, including right or left bundle branch block bifascicular block, and nonspecific intraventricular conduction block are common electrocardiogram (ECG) abnormalities with uncertain persistence and prognostic significance. We evaluated their trajectory and prognostic significance in patients undergoing coronary angiography. MethodsWe linked an institutional ECG repository with the provincial coronary angiography registry and administrative databases. We included patients without severe left ventricular dysfunction who had an ECG within 180 days of angiography. Multivariable Cox models were used to assess associations between conduction abnormalities and a composite outcome, including all-cause mortality, heart failure hospitalizations, placement of a permanent pacemaker, and placement of an implantable cardiac defibrillator or cardiac resynchronization therapy defibrillator. Serial ECGs were used to model conduction disease as a time-dependent repeated measure. ResultsWe included 10,786 patients (mean age, 62.3 ± 12.4 years; 70.3% were male), of whom 2530 (23.4%) had baseline conduction abnormality. During a median follow-up of 3.5 years, conduction normalized in 885 patients (34.9%) and the composite outcome occurred in 1541 patients (14.3%). After multivariable adjustment, intraventricular conduction block (adjusted hazard ratio, 1.42; P = 0.001) and bifascicular block (adjusted hazard ratio, 1.59; P = 0.003) were associated with increased risk of the composite outcome. Left bundle branch block was not associated with the composite outcome. ConclusionsRegression of conduction abnormalities was frequent among patients undergoing coronary angiography, primarily for suspected acute coronary syndrome. After adjustment for important confounders including extent of coronary artery disease, infranodal conduction abnormalities were associated with a modest increase in cardiovascular risk.

Sex differences in implantable cardiac defibrillator therapy according to arrhythmia detection times

ObjectiveIn implantable cardiac defibrillators (ICDs), long-detection times safely reduce unnecessary and inappropriate therapies. We aimed to evaluate ICD treatment of ventricular arrhythmias in women, compared with men, also taking into...

In This Issue of the Journal

In This Issue of the Journal

P1024Catheter ablation is associated with reduced all-cause mortality in a real-world cohort of patients with atrial fibrillation and heart failure

Abstract Background Atrial fibrillation (AF) and heart failure (HF) are common co-existing conditions. Randomized trial data suggests a reduction in all-cause mortality with catheter ablation (CA) in selected patients, however, whether these results are replicable in a real-world population and persist in the long-term remains to be shown. Purpose To evaluate the long-term effectiveness of CA in AF-HF patients in reducing the incidence of: a) all-cause mortality b) HF hospitalizations, and c) major morbidities (stroke/transient ischemic attack (TIA) and major bleeding). Methods A population-based administrative cohort was created of AF-HF patients with government prescription coverage in Quebec, Canada (1999–2015). Patients who underwent CA (cases) were matched 1:2 to controls using risk-set sampling. Cases were matched on time in the cohort and frequency of hospitalizations. Measured time-invariant confounders were controlled for using inverse probability of treatment weighting (IPTW) and included age, sex, clinical characteristics, presence of cardiac implantable electronic devices, and medication use. Multivariable Cox models adjusted the association of CA with the outcomes for the time varying confounders of the presence of an implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT), anticoagulation use (warfarin or direct oral anticoagulation), and any antiarrhythmic (AAD) use during follow-up. For non-fatal outcomes, the competing risk of death was accounted for using the Lunn-McNeil approach. Results Of the 87,676 AF-HF patients, 298 underwent CA and were matched to 591 controls. After IPTW, the distribution of covariates was balanced between cases and controls [age 65.6±11.0 vs 61.6±11.6; women 24% vs 20%; CHA2DS2-Vasc score 3.2±2.3 vs 2.9±2.1; CA vs non-CA, respectively; standardized mean differences &lt;0.1 for all]. Over a median follow-up of 3.3 (IQR 1.1–6.4) years, 19 (7.3%) of CA patients died compared to 144 (24.6%) non-CA patients. After weighting and adjustment, CA was associated with a statistically significant reduction in the incidence of all-cause mortality [adjusted HR 0.5 (95% CI 0.3–0.9)]. In addition, there was no statistically significant difference in the incidence of HF hospitalizations over the follow-up [CA: 22.5% vs non-CA: 27.1%; adjusted HR 0.9 (95% CI 0.6–1.2)]. The incidences of stroke/TIA (1.7% vs 6.8%) and major bleeding (1.7% vs 4.9%) for CA vs non-CA were not statistically different. Conclusion In a matched population-based AF-HF cohort, CA was associated with a reduced risk of all-cause mortality compared to patients who did not undergo CA. Although no difference in the risk of HF hospitalizations, stroke/TIA, and major bleeding was detected between CA and non-CA patients, larger studies are warranted. Acknowledgement/Funding Canadian Institute of Health Research; Fonds de recherché du Quebec-Santé, Clinical Research Scholar Award (V. Essebag) and Doctoral Award (M. Samuel)

P4510Impact of secondary tricuspid regurgitation on survival in heart failure - insights from COMMIT-HF registry

Abstract Background Functional tricuspid regurgitation (fTR) is common in left sided heart disease, especially in patients with concomitant left-sided valvular diseases and can lead to functional impairment and reduced survival. However, the impact of fTR on survival in chronic heart failure with reduced left ventricular ejection fraction (HFrEF) without severe left valvular diseases (LVD) is not fully established. The aim of the present study was to observe if moderate to severe fTR may influence the survival in patients with HFrEF without severe LVD. Methods We have analyzed a large single-center registry (n=2731) of HFrEF patients treated in a large-volume cardiovascular center between 2009–2015. After exclusion of patients with severe aortic and mitral valve disease we have included 2435 patients with HFrEF (left ventricular ejection fraction (LVEF) ≤35%). Functional moderate to severe tricuspid regurgitation without severe left valvular diseases was present in 465 patients. Twelve -month vital status was available for the whole patient population. Univariate and multivariate Cox proportional hazard regression models were performed to evaluate the relationship between moderate to severe fTR and mortality in the study group. Results Comparison of clinical data of fTR and non-fTR in HFrEF patients revealed some significant differences (age 63.3±12.9 vs 61.3±12.4, p=0.002; female sex 25.8% vs 17,9%, p&lt;0.001; chronic kidney disease stage III-V 45.3 vs 26.6%, p=0.001; atrial fibrillation 52.4% vs 28.5%, p&lt;0.001). Twelve-month all-cause mortality was over 2-fold higher in the fTR group (21.2% vs 8.1%, p&lt;0.001). There were no significant differences with regard to the medical treatment, implantable defibrillator or cardiac resynchronization therapy. The presence of fTR was identified as an independent echocardiographic factor impaired 12-month all-cause survival (HR 1.59, CI 1.2- 2.09, p&lt;0.001, figure 1) Conclusion Apart from the LVEF, the presence of moderate to severe fTR may predict 12-month all-cause mortality in patients with HFrEF. Acknowledgement/Funding None

P1669Frequency and patterns of implantable cardiac defibrillator therapies in patients with ventricular assist devices

Abstract Purpose Durable ventricular assist devices (VADs) use is a life-saving therapy in patients with end-stage heart failure. These patients are at high risk for ventricular arrhythmias. The pattern of ICD therapies in these patients is not well characterized. Methods Our single-center retrospective cohort included 86 patients with ICDs and VADs followed at our Centre. Data collected included frequency of ICD therapies, type of therapy (appropriate vs. inappropriate; shocks vs. anti-tachycardia pacing (ATP)), and time-course of therapies. Results 36 patients (42%) received ICD therapy during a mean follow-up period of 13.6 months. There were 105 episodes (2.9 episodes/patient) during which ICD therapies were delivered, with a total of 379 individual arrhythmias treated (3.6 arrhythmias per episode of therapy). 61.4% of therapies were appropriate, 8.4% were inappropriate, and 31.6% were unknown. Of the 79 episodes treated with appropriate therapy, 36 episodes (46%) required ICD shocks, whereas 43 episodes (54%) were treated with ATP alone. Overall, 33% of the total cohort and 81% of patients who received therapy received at least one ICD shock. Twenty-two patients (61%) received therapy between 1–3 times, while the remainder (14 patients, 39%) received therapy 3–10 times. Eighteen (17%) episodes occurred within the first month after LVAD implantation, with 10 (10%) occurring between 1–3 months, 53 (50%) occurring between 3–12 months, and 24 (23%) occurring more than one year after VAD implantation. Conclusion Analysis of our VAD cohort revealed three important findings: 1. ICD therapy is very common (42%) in the first year especially after LVAD implantation; 2. Ventricular arrhythmias are highly clustered in this cohort; 3. ATP is frequently effective. These findings have important implications on device follow-up and programming for this expanding patient population.