Cardiac Resynchronization Therapy-defibrillator Patients Research Articles

Clinical Significance of Atrial Tachyarrhythmia Duration for Ventricular Arrhythmia in Patients With Cardiac Resynchronization Therapy.

Atrial tachyarrhythmias (ATAs) are reportedly associated with ventricular arrhythmias (VAs). However, little is known about the association between ATA duration and the risk of VA. We investigated the relationship between ATA duration and subsequent VA in patients with a cardiac resynchronization therapy defibrillator (CRT-D).Methods and Results: We investigated associations between the longest ATA duration during the first year after cardiac resynchronization therapy (CRT) implantation and VA and VA relevant to ATA (VAATA) in 160 CRT-D patients. ATAs occurred in 63 patients in the first year. During a median follow-up of 925 days from 1 year after CRT implantation, 40 patients experienced 483 VAs. Kaplan-Meier analysis showed a significantly higher risk of VA in patients with than without ATA in the first year (log rank P=0.0057). Hazard ratios (HR) of VA (HR 2.36, 2.10, and 3.04 for ATA >30s, >6 min and >24 h, respectively) and only VAATA (HR 4.50, 5.59, and 11.79 for ATA >30s, >6 min and >24 h, respectively) increased according to the duration of ATA. In multivariate analysis, ATA >24 h was an independent predictor of subsequent VA (HR 2.42; P=0.02). Patients with ATA >24 h in the first year after CRT had a higher risk of subsequent VA and VAATA. The risk of VA, including VAATA, increased with the longest ATA duration.

Effect of Digitalis on ICD or CRT-D Recipients: A Systematic Review and Meta-Analysis

Digitalis has been widely utilized for heart failure therapy and several studies have demonstrated an association of digitalis and adverse outcome events in patients receiving implantable cardioverter defibrillators (ICDs) or cardiac resynchronization therapy defibrillators (CRT-Ds). Hence, we conducted this meta-analysis to assess the effect of digitalis on ICD or CRT-D recipients. We systematically retrieved relevant studies using the Cochrane Library, PubMed, and Embase database. A random effect model was used to pool the effect estimates (hazard ratios (HRs) and 95% confidence intervals (CIs)) when the studies were of high heterogeneity, otherwise a fixed effect model was used. Twenty-one articles containing 44,761 ICD or CRT-D recipients were included. Digitalis was associated with an increased rate of appropriate shocks (HR = 1.65, 95% CI: 1.46-1.86, p < 0.001) and a shortened time to first appropriate shock (HR = 1.76, 95% CI: 1.17-2.65, p = 0.007) in ICD or CRT-D recipients. Furthermore, the all-cause mortality increased in ICD recipients with digitalis therapy (HR = 1.70, 95% CI: 1.34-2.16, p < 0.01), but the all-cause mortality was unchanged in CRT-D recipients (HR = 1.55, 95% CI: 0.92-2.60, p = 0.10) or patients who received ICD or CRT-D therapy (HR = 1.09, 95% CI: 0.80-1.48, p = 0.20). The sensitivity analyses confirmed the robustness of the results. ICD recipients with digitalis therapy may tend to have higher mortality rates, but digitalis may not be associated with the mortality rate of CRT-D recipients. Further studies are required to confirm the effects of digitalis on ICD or CRT-D recipients.

Predicting the survival benefit of cardiac resynchronization therapy with defibrillator function for non-ischemic heart failure-Role of the Goldenberg risk score.

Primary prevention of sudden cardiac death (SCD) in non-ischemic heart failure (HF) patients remains a topic of debate at cardiac resynchronization therapy (CRT) implantation requiring individual risk assessment. Using the Goldenberg SCD risk score, we aimed to predict, which non-ischemic HF patients will benefit from the addition of an implantable cardioverter defibrillator (ICD) to CRT at long-term. Between 2000 and 2018 non-ischemic HF patients undergoing CRT implantation were collected into our retrospective registry. The Goldenberg risk score (GRS) was calculated by the presence of atrial fibrillation, New York Heat Association (NYHA) class > 2, age > 70 years, blood urea nitrogen > 26 mg/dl and QRS > 120 ms. The primary endpoint was all-cause mortality, heart transplantation or left ventricular assist device implantation. From 667 patients, 347 (52%) underwent cardiac resynchronization therapy-pacemaker (CRT-P), 320 (48%) cardiac resynchronization therapy-defibrillator (CRT-D) implantations. During the median follow up time of 4.3 years, 306 (46%) patients reached the primary endpoint (CRT-D 37% vs. CRT-P 63%; p < 0.001). CRT-D patients were younger (64 vs. 69 years; p < 0.001), infrequently females (26 vs. 39%; p < 0.001), and had a lower ejection fraction (27 vs. 29%; p < 0.01) compared to CRT-P patients. After GRS calculation, patients were dichotomized by low (< 3) and high (≥ 3) scores. CRT-D patients with low GRS showed a mortality benefit compared to CRT-P (HR 0.68; 95% CI 0.48-0.96; p = 0.03), high-risk patients did not (HR 0.84; 95% CI 0.62-1.13; p = 0.26). In our non-ischemic cohort, patients with low GRS showed a clear long-term mortality benefit by adding ICD to CRT, however, in high-risk patients no further benefit could be observed.

CRT-D replacement strategy: results of the BioCONTINUE study.

In patients with cardiac resynchronization therapy defibrillators (CRT-Ds), the need for implantable cardioverter-defibrillator (ICD) back-up may be questionable at time of CRT-D replacement (REP) if ICD implant criteria are no longer met due to an improved left ventricular ejection fraction (LVEF) and if no major ventricular arrhythmic event (VAE) occurred during the CRT-D lifetime. The aim of our study was to assess the relevance of ICD back-up and predictors of VAE after REP in primary prevention CRT-D patients. The prospective, observational, international BioCONTINUE study investigated the rate of patients with at least 1 sustained VAE (sVAE) post-REP and searched for predictive factors of sVAE. Two hundred seventy-six patients (70 ± 10years, 77% men, mean LVEF 40.6 ± 12.6%) were followed for 28.4 ± 10.2months. The rate of patients with sVAE was 8.3%, 10.3%, and 21.2% at 1, 2, and 4years post-REP. Patients without persistent ICD indication at REP still had a sVAE rate of 5.7% (95% CI 2.3-11.5%) at 2years. In multivariate analysis, predictive factors of subsequent sVAE were (i) persistent ICD indication (hazard ratio (HR) 3.6; 95% CI 1.6-8.3; p = 0.003); (ii) 64-72years of age as compared to ≥ 79years (HR 3.7; 95% CI 1.4-9.7; p = 0.008); and (iii) ischemic heart disease (HR 4.4; 95% CI 2.1-9.3; p < 0.0001). The risk of sVAE (21.2% at 4years post-REP) depends on age, ischemic heart disease, and ICD indication at the time of REP. A non-trivial risk of sVAE remains in patients without persistent ICD indication. NCT02323503.

Ventricular Arrhythmias and Implantable Cardioverter-Defibrillator Therapy inWomen: A Propensity Score-Matched Analysis.

Causes of sex differences in incidence of sustained ventricular arrhythmias (SVAs) are poorly understood. This study aims to investigate sex-specific risk of SVAs and device therapies by balancing sex groups in relation to several baseline characteristics with the propensity score (PS). We used a large remote monitoring dataset from implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds). Study endpoints were time to the first appropriate SVA, time to the first device therapy for SVA, and time to the first ICD shock. Results were compared between females and a PS-matched male subgroup. In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. After selecting 488 men PS-matched for 19 variables relative to baseline demographics, implant indications, principal comorbidities, and concomitant therapy, yet the SVA rate at the 2.1-year median follow-up was significantly lower in women than in man (adjusted HR: 0.65; 95%CI: 0.51-0.81; P< 0.001). Women also showed a reduced risk of any device therapy (HR: 0.59; 95%CI: 0.45-0.76; P< 0.001) and shocks (HR: 0.66; 95%CI: 0.47-0.94; P=0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR: 0.78; 95%CI: 0.55-1.09; P=0.14) nor in those with an ejection fraction<30% (HR: 0.80; 95%CI: 0.52-1.23; P=0.31). After matching demographics, indications, principal comorbidities, and concomitant therapy, women still exhibited a lower SVA risk profile than men, except in the subgroups of CRT-D or/and ejection fraction<30%.

Ventricular arrhythmias and implantable cardioverter-defibrillator therapy in women: a propensity score-matched analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The implantable cardioverter-defibrillator (ICD) is an established therapy for the prevention of sudden cardiac death in selected patients. Although current guidelines apply to both women and men, there is a growing awareness that the incidence of cardiac arrhythmias and device interventions is influenced by sex. Purpose To investigate sex-specific risk of sustained ventricular arrhythmias (SVAs) and device therapies, using remote monitoring data from ICDs and cardiac resynchronization therapy defibrillators (CRT-Ds). Methods Study endpoints were time to the first appropriate SVA, time to the first appropriate device therapy for SVA, and time to the first ICD shock. Appropriateness of device-detected SVAs was adjudicated by three expert electrophysiologists. Results were compared between women and a 1:1 propensity score (PS)-matched subgroup of men. Results In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. As compared to men, women more frequently had a CRT-D (51% vs. 40%, p&amp;lt;0.001), and nonischemic cardiomyopathy (65% vs. 45%, p&amp;lt;0.001). After a median follow-up of 2.1 years, SVAs occurred in 123 women (25.2%) and in 174 of the 488 PS-matched men (35.6%) with an adjusted hazard ratio (HR) of 0.65 (95% confidence interval [CI], 0.51-0.81; p&amp;lt;0.001). Women also showed a reduced risk of any device therapy (HR, 0.59; CI, 0.45-0.76; p&amp;lt;0.001) and shocks (HR, 0.66; CI, 0.47-0.94, p=0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR, 0.78; CI, 0.55-1.09; p=0.14) and in those with an ejection fraction &amp;lt;30% (HR, 0.80; CI, 0.52-1.23; p=0.31). Conclusion In our analysis of remote monitoring data, women exhibited a lower SVA risk profile than PS-matched men in the subgroup of patients with an ICD or/and ejection fraction ≥30%.

Determinants of worse prognosis in patients with cardiac resynchronization therapy defibrillators. Are ventricular arrhythmias an adjunctive risk factor?

Cardiac resynchronization therapy (CRT) is indicated in patients with systolic heart failure (HF), severe left ventricle (LV) dysfunction and interventricular dyssynchrony.In prospective observational research, we aimed to evaluate whether CRT-induced LV reverse remodelling and occurrence of ventricular arrhythmias (VT/VF) independently contribute to prognosis in patients with CRT defibrillators (CRT-D). In 95 Italian cardiological centres, after a screening period of 6 months, patients were categorized according to VT/VF occurrence and CRT response, defined as LV end-systolic volume relative reduction >15% or LV ejection fraction absolute increase >5%. The main endpoint was death or HF hospitalizations. Among 1308 CRT-D patients (80% male, mean age 66 years), at 6 months, follow-up 71% were identified as CRT responders and 12% experienced appropriate VT/VF detections. The main endpoint was significantly and independently associated with previous myocardial infarction, New York Heart Association Class, VT/VF occurrence and with CRT response. CRT nonresponder patients who suffered VT/VF in the screening period had a risk of death or HF hospitalizations [HR = 7.82, 95% confidence interval (CI) = 3.95-15.48] significantly (P < 0.001) higher than CRT responders without VT/VF occurrence. This risk is mitigated without VT/VF occurrence (HR = 3.47, 95% CI = 2.03-5.91, P < 0.001) or in case of CRT response (HR = 3.11, 95% CI = 1.44-6.72, P = 0.004). Our data show that both CRT response and occurrence of VT/VF independently contribute to the risk of death or HF-related hospitalizations in CRT-D patients. Early VT/VF occurrence may be identified as a marker of disease severity than can be mitigated by CRT response both in terms of all-cause mortality and long-term VT/VF onset. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00147290 and NCT00617175.

Changes in quality of life, depression, general anxiety, and heart-focused anxiety after defibrillator implantation.

AimsThe Anxiety‐CHF (Anxiety in patients with Chronic Heart Failure) study investigated heart‐focused anxiety (HFA, with the dimensions fear, attention, and avoidance of physical activity), general anxiety, depression, and quality of life (QoL) in patients with heart failure. Psychological measures were assessed before and up to 2 years after the implantation of an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy defibrillator (CRT‐D).Methods and resultsOne hundred thirty‐two patients were enrolled in this monocentric prospective study (44/88 CRT‐D/ICD, mean age 61 ± 14 years, mean left ventricular ejection fraction 31 ± 9%, and 29% women). Psychological assessment was performed before device implantation as well as after 5, 12, and 24 months. After device implantation, mean total HFA, HFA‐fear, HFA‐attention, general anxiety, and QoL improved significantly. Depression and HFA‐related avoidance of physical activity did not change. CRT‐D patients compared with ICD recipients and women compared with men reported worse QoL at baseline. Younger patients (<median of 63 years) had higher levels of general anxiety and lower levels of HFA‐avoidance at baseline than older patients. After 24 months, groups no longer differed from each other on these scores. Patients with a history of shock or anti‐tachycardia pacing (shock/ATP; N = 19) reported no improvements in psychological measures and had significantly higher total HFA and HFA‐avoidance levels after 2 years than participants without shock/ATP.ConclusionsAnxiety and QoL improved after device implantation, and depression and HFA‐avoidance remained unchanged. HFA may be more pronounced after shock/ATP. Psychological counselling in these patients to reduce HFA and increase physical activity should be considered.

The incidence, clinical significance of depression and its clinical course after a cardac device implantation in patients with severe heart failure

Abstract Aim To assess the incidence, clinical significance of depression and the impact of a cardioverter-defibrillator (ICD) or cardiac resynchronization therapy-defibrillator (CRT-D) implantation on psychiatric status in patients with heart failure (HF). Methods The prospective, single-center study encompassed 575 consecutive HF patients implanted with a CRT-D or ICD. Finally, the study population consisted of 494 subjects (186 ICD and 308 CRT-D patients), as 81 patients taking antidepressants were excluded from the analysis. All patients underwent psychiatric examination at the time of implantation, and the assessment of psychiatric status was repeated after 3, 6, 12 and 24 months. The study population was divided into 4 groups: Group 1 encompassed 101 (20.4%) patients with persistent depression, Group 2 constituted of 95 (19.2%) patients with depression that developed after ICD/CRT-D implantation, whereas 43 (8.7%) patients with remission of depression comprised Group 3, and Group 4 encompassed 255 (51.6%) patients with never diagnosed depression. Data on long-term follow-up (median 34.1 months) were screened to identify patients who developed a composite endpoint defined as death or hospitalization for decompensated HF. Results The cumulative incidence of depression at the baseline assessment was 39.1%. Depression developed in 95 (27.1%) patients, whereas remission of depression was observed in 43 (29.9%) subjects after ICD/CRT-D implantation. ICD intervention (HR 3.3) and increase in NYHA class by at least one class (HR 2.6) were the independent risk factors for depression development, whereas mitral regurgitation reduction (HR 1.9), as well as improvement in NYHA class by at least one class (HR 2.4) were the independent predictors for depression remission. Patients with persistent depression (Group 1) and those with newly developed depression (Group 2) were at significantly higher risk of a composite endpoint compared to patients in Group 3 and Group 4 (Table 1). Conclusions Depression is a common comorbidity associated with HF, as it affects 4 of 10 HF patients. ICD intervention and HF worsening are the strongest predictors for depression development after ICD/CRT-D implantation. Depression is a strong, independent risk factor of poor outcomes in HF population. Funding Acknowledgement Type of funding source: None

Evaluation of an Integrated Device Diagnostics Algorithm to Risk Stratify Heart Failure Patients - Results From the SCAN-HF Study.

Integrated device diagnostics, Triage-HF, is useful in risk stratifying patients with heart failure (HF), but its performance for Japanese patients remains unknown. This is a prospective study of Japanese patients treated with a cardiac resynchronization therapy defibrillator (CRT-D), with a Medtronic OptiVol 2.0 feature.Methods and Results:A total of 320 CRT-D patients were enrolled from 2013 to 2017. All received HF treatment in the prior 12 months. Following enrollment, they were followed every 6 months for 48 months (mean, 22 months). Triage-HF-stratified patients at low, medium and high risk statuses at every 30-day period, and HF-related hospitalization occurring for the subsequent 30 days, were evaluated and repeated. The primary endpoint was to assess Triage-HF performance in predicting HF-related hospitalization risk. All device data were available for 279 of 320 patients (NYHA class II or III in 93%; mean left ventricular ejection fraction, 31%). During a total of 5,977 patient-month follow-ups, 89 HF-related hospitalization occurred in 72 patients. The unadjusted event numbers for Low, Medium and High statuses were 19 (0.7%), 42 (1.6%) and 28 (4.1%), respectively. Relative risk of Medium to Low status was 2.18 (95% CI 1.23-3.85) and 5.78 (95% CI 3.34-10.01) for High to Low status. Common contributing factors among the diagnostics included low activity, OptiVol threshold crossing, and elevated night heart rate. Triage-HF effectively stratified Japanese patients at risk of HF-related hospitalization.

Appropriate and inappropriate therapy in patients with single- or multi-chamber implantable cardioverter-defibrillators

BackgroundInappropriate ICD therapy is associated with adverse outcome. Previous studies indicated that patients with a cardiac resynchronization therapy-defibrillator (CRT-D) might have a lower risk for inappropriate device activations than patients with a single (VVI) or dual chamber (DDD) ICD. MethodsAll ICD recipients from a university cardiac center between 2000 – 2015 were included in this analysis. Outcome parameters were incidence of appropriate and inappropriate therapy and overall mortality. ResultsA total of 1471 patients were analyzed: 629 (43%) patients with a VVI-ICD, 486 (33%) patients with a DDD-ICD and 356 (24%) with a CRT-D device. During an average follow-up of 4.1 ± 3.6 years, CRT-D patients had the lowest risk to receive at least one inappropriate shock therapy (p < 0.001). Rates of appropriate (RR (Rate Ratio) = 0.45, p = 0.019) and inappropriate shock therapy (RR = 0.38, p = 0.021) were significantly lower in CRT-D patients compared to VVI-patients. CRT-D recipients had a lower rate of appropriate shock therapy (RR = 0.323, p = 0.043) compared to DDD patients, but not of inappropriate shock therapy (p = 0.371). Kaplan Meier Analysis did not reveal a significant difference in overall survival (p = 0.396). However, after adjustment for relevant confounding factors, VVI-patients had a higher risk for overall-death (HR = 1.28, p = 0.030). ConclusionsCRT-D recipients have a significantly lower rate of appropriate shock therapy and a lower rate of inappropriate shock therapy. More frequent inappropriate therapies in VVI-ICD recipients may account for their higher overall mortality.

Longest Paced versus Sensed Electrical Delay Programming in Cardiac Resynchronization Therapy Defibrillator Patients with Quadripolar LV Leads: Results from the PASED-CRT Randomized Trial

Introduction Cardiac resynchronization therapy (CRT) is a well-established treatment for patients with drug refractory heart failure. The PASED-CRT trial (NCT-02803775) compared the efficacy of the longest RVsense to LVsense activation time (sLAT) versus the longest RVpace to LVsense activation time (pLAT) as the site of the LV pacing cathode on quadripolar LV leads. Methods The PASED-CRT trial is a single site, double blind, randomized, prospective trial. Patients were randomized to sLAT or pLAT in a 1:1 ratio. The site of Left ventricular pacing was programmed bases on the longest electrical delay measured and maintained thru 3 months. Blinded physicians and assessors compared the 6-minute hall walk test (6MWT), NYHA, MLWHF, and Clinical Composite Score (CCS) at 3 months. Results N=92 patients (20%F) 66 (±11.3 years) were randomized and programmed per protocol. Patients and physicians were blinded to programming assignment. Baseline patient characteristics were comparable between groups. N=38 sLAT and N=34 pLAT completed the 3 month visit for the final analysis. The pLAT group had a greater CCS compared 82.4% vs. the sLAT 55.3% (P=0.016) and had a mean 20.63m increase over the sLAT in 6MWT distance at 3 months. (P=N/S) Conclusions Utilizing the pLAT demonstrated improved 6MWT distance and a significant difference in CCS over the programming to the sLAT. These results should be considered in patients with intrinsic conduction and those without as no measurement is currently available. Future studies with longer follow-ups are warranted to confirm these findings.

T wave positivity in lead aVR is associated with mortality in patients with cardiac resynchronization therapy.

Positive T wave polarity in lead aVR (TPaVR) is associated with a poor prognostic indicator in patients with heart failure reduce ejection fraction (HFrEF). Our aim was to investigate the relationship between positive TPaVR and mortality in patients with cardiac resynchronization therapy defibrillator (CRT-D). We included retrospectively 224 HFrEF patients with CRT-D in sinus rhythm. Laboratory, electrocardiographic (ECG), and echocardiographic data were recorded. T wave polarity was measured in lead DI, DII, and aVR from surface ECG. The patients were divided as living and deceased. They followed for 2.5 ± 0.9years. Thirty-three patients (14.7%) died. Six patients (18.2%) were TPaVR positive before CRT-D and this number increased to 22 (66.6%) after CRT-D in the deceased group. Pulse (p = 0.049), hyperlipidemia (p = 0.022), and NT-proBNP levels were higher in the deceased group (p = 0.001). TPaVR before CRT-D (p < 0.001) and TPaVR after CRT-D (p < 0.001) were significantly positive in the deceased group. Positive TPaVR after CRT-D was the only independent predictor for mortality in binominal logistic regression analysis (OR 1.211, 95% CI 1.105-1.328, p < 0.001). In CRT-D patients, a positive TPaVR in surface ECG may be a strong mortality indicator.

Risk stratification of cardiovascular and heart failure hospitalizations using integrated device diagnostics in patients with a cardiac resynchronization therapy defibrillator.

Cardiac resynchronization therapy defibrillators (CRT-D) are able to monitor various parameters that may be combined by an automatic algorithm to provide a heart failure risk status (HFRS). We sought to validate the HFRS for stratifying patient risk, evaluate its association with heart failure (HF) symptoms, and investigate its utility for triage of automatic alerts. Data from 722 patients included in the MORE-CARE trial were analysed in a post hoc analysis. A high HFRS was associated with a significantly increased risk of admission over the next 30 days with a relative risk for cardiovascular hospitalization (CVH) of 4.5 (95% CI: 3.1-6.6, P < 0.001), of HF hospitalization of 6.3 (95% CI: 3.9-10.2, P < 0.001) and of non-HF related CVH of 3.5 (95% CI: 2.0-6.9, P < 0.001). The negative predictive value of low or medium HFRS for these admissions was ≥98%. A high HFRS was associated with an increased risk of HF symptoms. Of all the automatic remote monitoring alerts generated during the study, only 10% had a high HFRS. The HFRS is able to risk-stratify CRT-D patients, which is potentially useful for managing automatic remote monitoring alerts, by focusing attention on the minority of high-risk patients. The trial was registered at www.clinicaltrials.gov under number NCT00885677.

A Device Histogram‐Based Simple Predictor of Mortality Risk in ICD and CRT‐D Patients: The Heart Rate Score

We hypothesized that survival in implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) patients is predicted by baseline Heart Rate Score. Heart Rate Score is determined from the atrial paced and sensed histogram of a DDD ICD or CRT-D, and defined as percent of beats in the histogram in the tallest 10 beats/min range bin. It was calculated at initial remote monitoring for patients enrolled in LATITUDE® without persistent atrial fibrillation, and with pulse generators implanted in 2006-2011. Univariate, multivariate, and Kaplan-Meier analyses determined the impact of Heart Rate Score on survival. Of 57,893 ICDs and 67,929 CRT-Ds followed for 2.4 ± 1.5 years, each 10% increase in Heart Rate Score was associated with decreased survival (CRT-D hazard ratio [HR] 1.07 95%, confidence interval 1.06-1.07, P < 0.0001; ICD HR 1.05, 95% confidence interval 1.04-1.06, P < 0.0001). Multivariate analysis showed survival decreased with increasing age, atrial fibrillation, presence of a shock in first-year follow-up, and increasing programmed lower pacing rate in ICD and CRT-D patients. Increased percent right ventricular pacing predicted mortality in ICD patients, while male gender and lower percent left ventricular pacing predicted mortality in CRT patients. Heart Rate Score predicted survival independent of those variables. Heart Rate Score correlates with heart rate variability (standard deviation of average R-R intervals [SDANN]) when both are obtainable, but SDANN was only present in 6% of patients with Heart Rate Score >70%. A simple device histogram measure, Heart Rate Score, predicts survival in ICD and CRT-D patients independent of the available variables, and even when SDANN is unavailable.

Effectiveness of a management program for outpatient clinic or remote titration of beta-blockers in CRT patients: The RESTORE study

BackgroundMany patients fail to receive β-blockers before cardiac resynchronization therapy defibrillator (CRT-D) implantation, or receive them at a suboptimal dose, and require optimization after implantation. We assessed the effectiveness of a structured program for β-blocker titration in CRT-D patients followed up by means of conventional in-clinic visits or remote monitoring. Methods and results130 patients undergoing CRT implantation and treated according to the standard practice of the centers were included as a control group. A second group of 124 CRT-D candidates (Study Group) underwent up-titration visits every 2weeks after implantation (target dose: 10mg/day of bisoprolol or 50mg/day of carvedilol). In the Study Group, remote monitoring was undertaken in 66 patients, who received additional equipment for daily transmission of weight and blood pressure data, and scheduled titration telephone calls. In the Control Group, the maximal dose of β-blockers was being administered to 12 (9%) patients on implantation and 21 (16%) on 6-month follow-up examination (p>0.05). In the Study Group, 25 (20%) patients were receiving the maximal dose of β-blockers on implantation and 72 (58%) on follow-up examination (p<0.001). The 66 Study Group patients on remote monitoring underwent fewer in-clinic visits (p=0.034). Of these, 50 (76%) were on the maximal dose after remote up-titration (versus 38% of patients followed up conventionally, p<0.001). The decrease in left ventricular end-systolic volume was larger in the Study Group (p=0.040). ConclusionsThe program for β-blocker up-titration increased the number of patients reaching the target dose and improved the response to the therapy. The use of remote monitoring and daily transfer of weight and blood pressure data facilitated β-blocker titration. Clinical trial registrationURL: http://clinicaltrials.gov/Identifier: NCT02173028.

Management of functional Sprint Fidelis leads at cardiac resynchronization therapy-defibrillator generator replacement: a novel option for preventing inappropriate shocks from lead failure in fragile patients with high risk of sudden death.

In patients with a functional Sprint Fidelis lead at generator replacement, the manufacturer recommended to either continue to use the existing lead or replace it with a new lead. For those patients who continue to use a functional Fidelis lead, the risk of inappropriate shocks remains present if the lead fails in the future. We evaluated the feasibility of an alternative approach at the time of cardiac resynchronization therapy-defibrillator (CRT-D) generator replacement in patients with a functional bipolar left ventricular (LV) lead for prevention of inappropriate shocks from future Fidelis lead failure. During the procedure, the pace/sense IS-1 connection pin of the functional Fidelis lead was intentionally inserted into the LV port of the new CRT-D generator, while the existing bipolar LV lead IS-1 connection pin was inserted into the right ventricular (RV) pace/sense port. After such switching, the existing bipolar LV lead was used for functional LV pacing/sensing, while the Fidelis lead was used for functional RV pacing and high voltage shock only and could no longer be used for the purpose of sensing and detecting. This approach precluded oversensing and inappropriate shocks should the functional Fidelis lead fail in the future. Six fragile patients, who were not considered suitable candidates for lead replacement, underwent the alternative approach. During a follow-up of 35 ± 23 months, the CRT-D system functioned normally in five patients. The Fidelis lead fractured in one patient 7 months after generator replacement. The malfunction was detected promptly and the defected lead was replaced. No inappropriate detections or shock was triggered. In CRT-D patients with a functional Fidelis lead and a bipolar LV lead, switching of the Fidelis lead pace/sense IS-1 pin with the bipolar LV lead IS-1 pin at generator replacement did not affect normal system function. This novel approach may be valuable in fragile patients with high risk of sudden death for prevention of inappropriate shocks triggered by oversensing from a malfunctioning Fidelis lead.

Survival After Rate-Responsive Programming in Patients With Cardiac Resynchronization Therapy-Defibrillator Implants Is Associated With a Novel Parameter: The Heart Rate Score.

Rate-responsive pacing (DDDR) versus nonrate-responsive pacing (DDD) has shown no survival benefit for patients undergoing cardiac resynchronization therapy defibrillator (CRT-D) implants. The heart rate score (HRSc), an indicator of heart rate variation, may predict survival. We hypothesized that high-risk HRSc CRT-D patients will have improved survival with DDDR versus DDD alone. All CRT-D patients in LATITUDE remote monitoring (2006-2011), programmed DDD, had HRSc calculated at first data upload after implant (median 1.4 months). Patients subsequently reprogrammed to DDDR 7.6 median months later were compared with a propensity-matched DDD group and followed for 21.4 median months by remote monitoring. Data were adjusted for age, sex, lower rate limit, percent atrial pacing, percent biventricular pacing, and implant year. The social security death index was used to identify deaths. Remote monitoring provided programming and histogram data. DDDR programming in CRT-D patients was associated with improved survival (adjusted hazard ratio =0.77; P<0.001). However, only those with baseline HRSc ≥70% (2308/6164) had improved HRSc with DDDR (from 88±9% to 78±15%; P<0.001) and improved survival (hazard ratio =0.74; P<0.001). Patients with a high baseline HRSc and significant improvement over time were more likely to survive (hazard ratio =0.63; P=0.006). For patients with HRSc <70%, DDDR reprogramming increased the HRSc from 46±11% to 50±15% (P<0.001); survival did not change. The HRSc did not change with DDD pacing over time. In CRT-D patients with HRSc ≥70%, DDDR reprogramming improved the HRSc and was associated with survival. Patients with lower HRSc had no change in survival with DDDR programming.

Battery drain in daily practice and medium-term projections on longevity of cardioverter-defibrillators: an analysis from a remote monitoring database.

AimsThe longevity of generators is a crucial determinant of the cost-effectiveness of therapy with implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-D). We evaluated the trend of device-measured residual battery capacity and longevity projections over 5-year follow-up. We also investigated possible factors associated with battery drain.Methods and resultsData from 4851 patients in the European LATITUDE® database who were followed up for a minimum of 3 years were analysed. The factors associated with battery drain (i.e. year-to-year decrease in residual battery capacity), and thus potentially impacting on device longevity, were mainly the pacing parameters in CRT-D devices and the number of shocks delivered and diverted in both ICD and CRT-D (all P < 0.01 on linear regression analysis). Over the first 5 years, the longevity estimates provided by devices showed low intra-patient variability and increased with time. The estimates exceeded 10 years for CRT-D and 13 and 12 years for single- and dual-chamber ICDs, respectively. In CRT-D patients, the expected patient age on replacement was 80 ± 12 years, and the expected probability of undergoing device replacement was 63 ± 13% for New York Heart Association (NYHA) II patients and 37 ± 16% for NYHA III patients. For comparison, the probabilities of replacing a CRT-D lasting 5 years were 78 ± 8 and 59 ± 13%, respectively (both P < 0.001).ConclusionBattery drain was mainly associated with pacing output in CRT-D devices and with the number of capacitor charges in both ICD and CRT-D devices. The longevity estimates provided by the devices were consistent and conservative. According to these estimates, among CRT-D recipients a low proportion of patients should require device replacement.

Normalization of Left Ventricular Ejection Fraction and Incidence of Appropriate Antitachycardia Therapy in Patients With Implantable Cardioverter Defibrillator for Primary Prevention of Sudden Death

BackgroundPatients with severely depressed left ventricular ejection fractions (LVEFs) receive implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden death. In some patients, however, LVEF may improve or even normalize over time. Limited data are available on the incidence of appropriate antitachycardia therapy, including pacing and shock, in these patients. Methods and ResultsWe retrospectively identified consecutive patients at our institution with an ICD for primary prevention who had LVEF measurement available at initial implantation and at the time of generator replacement. None of these patients had ever received appropriate antitachycardia therapy before generator replacement. The incidence of appropriate antitachycardia therapy after generator replacement was assessed. Of the 125 patients who received generator replacement, 53 (42%) received an ICD and 72 (58%) a cardiac resynchronization therapy–defibrillator (CRT-D). Among them, 30 (21%) had LVEF normalized to ≥50%, 25 (17%) had LVEF partially improved to 36%–49%, and 70 (63%) had LVEF that remained depressed at ≤35%. During an overall follow-up period of 25 ± 18 months, none of the individuals with normalized LVEF experienced appropriate antitachycardia therapy regardless of ICD or CRT-D. Meanwhile, 20% of patients with LVEF at 36%–49% and 14% of patients with LVEF at ≤35% received appropriate ICD therapy. The omnibus P value for any differences among the 3 LVEF groups was 0.046 for the entire cohort, 0.01 for ICD, and 0.15 for CRT-D patients. ConclusionsThese preliminary data suggest that patients with reduced LVEF and primary-prevention ICDs who normalize their LVEF over time may be at lower risk of appropriate antitachycardia therapy.