Cardiac Resynchronization Therapy Recipients Research Articles

Baseline adverse electrical remodeling and the risk for ventricular arrhythmia in Cardiac Resynchronization Therapy Recipients (MADIT CRT).

Adverse electrical remodeling (AER), represented here as the sum absolute QRST integral (SAI QRST), has previously been shown to be directly associated with the risk for ventricular arrhythmia (VA). Cardiac resynchronization therapy (CRT) is known to reduce the risk for VA through various mechanisms, including reverse remodeling, and we aimed to evaluate the association between baseline AER and the risk for VA in CRT recipients. The study population comprised 961 CRT-D implanted patients from the MADIT CRT study. The relationship between SAI QRST, VA risk, and VA risk/death was evaluated as a continuous and as a categorical variable-tertiles (T1 ≤ 0.527, T2 0.528-0.766, T3>0.766). In a multivariable model, AER was inversely associated with the risk of VA. Each unit increase in SAI QRST was associated with 64% (P=0.007) and 54% (P=0.003) decrease in the risk of VA and VA/death, respectively. Patients with high SAI QRST (T3) and medium SAI QRST (T2) had 52% (P<0.001) and 32% (P=0.027) reduced risk for VA and 44% (P=0.002) and 26% (P=0.055) reduced risk for VA/death as compared with patients with low SAI QRST (T1), respectively. In CRT implanted patients with mild heart failure, baseline AER was inversely associated with the risk for VA and VA/death; this is a finding that contradicts the relationship previously reported in non-CRT implanted patients. We theorize that CRT may abate the process of AER; however, characterization of this mechanism requires further study.

Reduced left ventricular mechanical dispersion at 6 months follow-up after cardiac resynchronization therapy is associated with superior long-term outcome

In heart failure (HF) patients, left ventricular mechanical dispersion (LVMD) reflects heterogeneous mechanical activation of the left ventricle. In HF patients, LVMD can be reduced after CRT. Whether lesser LVMD is associated with improved outcome is unknown. The purpose of this study was to relate LVMD to long-term prognosis in a large cohort of HF patients after 6 months of cardiac resynchronization therapy (CRT). Clinical, echocardiographic, and ventricular arrhythmia (VA) data were analyzed from an ongoing registry of HF recipients of CRT. Baseline (before CRT) and 6-month echocardiograms were evaluated. LVMD was calculated as the standard deviation of the time from onset of the QRS complex to the peak longitudinal strain in a 17-segment model. Patients were divided into 2groupsaccording to the median LVMD (84 ms) at 6 months post-CRT. Of 1185 patients (mean age 65 ± 10 years; 76% male), 343 (29%) died during a mean follow-up of 55 ± 36 months. Baseline LVMD was not associated with all-cause mortality and VA at follow-up. In contrast, patients with less LVMD (≤84 ms) at 6 months post-CRT had lower event rates (VA and mortality) compared to those with LVMD >84 ms. On multivariable analysis, greater LVMD at 6 months after CRT was independently associated with an increased risk of mortality (hazard ratio 1.002; P = .037) and VA (hazard ratio 1.003; P = .026). Larger LVMD at 6 months after CRT is independently associated with all-cause mortality and VA. LVMD may be valuable in identifying patients who remain at high mortality risk after CRT implantation.

Atrial electrogram quality in single-pass defibrillator leads with floating atrial bipole in patients with permanent atrial fibrillation and cardiac resynchronization therapy

Many patients receiving cardiac resynchronization therapy (CRT) suffer from permanent atrial fibrillation (AF). Knowledge of the atrial rhythm is important to direct pharmacological or interventional treatment as well as maintaining AV-synchronous biventricular pacing if sinus rhythm can be restored. A single pass single-coil defibrillator lead with a floating atrial bipole has been shown to obtain reliable information about the atrial rhythm but has never been employed in a CRT-system. The purpose of this study was to assess the feasibility of implanting a single coil right ventricular ICD lead with a floating atrial bipole and the signal quality of atrial electrograms (AEGM) in CRT-defibrillator recipients with permanent AF. Methods and resultsSeventeen patients (16 males, mean age 73 ± 6 years, mean EF 25 ± 5%) with permanent AF and an indication for CRT-defibrillator placement were implanted with a designated CRT-D system comprising a single pass defibrillator lead with a atrial floating bipole. They were followed-up for 103 ± 22 days using remote monitoring for AEGM transmission. All patients had at last one AEGM suitable for atrial rhythm diagnosis and of 100 AEGM 99% were suitable for visual atrial rhythm assessment. Four patients were discharged in sinus rhythm and one reverted to AF during follow-up. ConclusionAtrial electrograms retrieved from a single-pass defibrillator lead with a floating atrial bipole can be reliably used for atrial rhythm diagnosis in CRT recipients with permanent AF. Hence, a single pass ventricular defibrillator lead with a floating bipole can be considered in this population.

Study design and rationale for biomedical shirt-based electrocardiography monitoring in relevant clinical situations: ECG-shirt study.

Today, the main challenge for researchers is to develop new technologies which may help to improve the diagnoses of cardiovascular disease (CVD), thereby reducing healthcare costs and improving the quality of life for patients. This study aims to show the utility of biomedical shirt-based electrocardiography (ECG) monitoring of patients with CVD in different clinical situations using the Nuubo® ECG (nECG) system. An investigator-initiated, multicenter, prospective observational study was carried out in a cardiology (adult and pediatric) and cardiac rehabilitation wards. ECG monitoring was used with the biomedical shirt in the following four independent groups of patients: 1) 30 patients after pulmonary vein isolation (PVI), 2) 30 cardiac resynchronization therapy (CRT) recipients, 3) 120 patients during cardiac rehabilitation after myocardial infarction, and 4) 40 pediatric patients with supraventricular tachycardia (SVT) before electrophysiology study. Approval for all study groups was obtained from the institutional review board. The biomedical shirt captures the electrocardiographic signal via textile electrodes integrated into a garment. The software allows the visualization and analysis of data such as ECG, heart rate, arrhythmia detecting algorithm and relative position of the body is captured by an electronic device. The major advantages of the nECG system are continuous ECG monitoring during daily activities, high quality of ECG recordings, as well as assurance of a proper adherence due to adequate comfort while wearing the shirt. There are only a few studies that have examined wearable systems, especially in pediatric populations. This study is registered in ClinicalTrials.gov: Identifier NCT03068169. (Cardiol J 2018; 25, 1: 52-59).

Effect of cardiac resynchronization therapy on mitral valve geometry: a novel aspect as "reversed mitral remodeling".

Amelioration of the valvular geometry is a possible mechanism for mitral regurgitation (MR) improvement in patients receiving cardiac resynchronization therapy (CRT). We aimed to establish the precise definition, incidence, and predictors of reversed mitral remodeling (RMR), as well as the association with MR improvement and short-term CRT outcome. Ninety-five CRT recipients were retrospectively evaluated for the end-point of "MR response" defined as the absolute reduction in regurgitant volume (RegV) at 6 months. To identify RMR, changes in mitral deformation indices were tested for correlation with MR response and further analyzed for functional and echocardiographic CRT outcomes. Overall, MR response was observed in 50 patients (53%). Among the echocardiographic indices, the change in tenting area (TA) had the highest correlation with the change in RegV (r = 0.653, p < 0.001). The mean TA significantly decreased in MR responders (4.15 ± 1.05 to 3.67 ± 1.01 cm2 at 6 months, p < 0.001) and increased in non-responders (3.68 ± 1.04 to 3.98 ± 0.97 cm2, p = 0.014). The absolute TA reduction was used to identify patients with RMR (47%) which was found to be associated with higher rates of functional improvement (p = 0.03) and volumetric CRT response (p = 0.036) compared to those without RMR. Non-ischemic etiology and the presence of LBBB independently predicted RMR at multivariate analysis. In conclusion, reduction in TA is a reliable index of RMR, which relates to MR response, and functional and echocardiographic improvement with CRT. LBBB and non-ischemic etiology are independent predictors of RMR.

Longer inter-lead electrical delay is associated with response to cardiac resynchronization therapy in patients with presumed optimal left ventricular lead position.

In a randomized trial of cardiac resynchronization therapy (CRT), a presumed optimal left ventricular (LV) lead position close to the latest mechanically activated non-scarred myocardium was achieved in 98% of patients by standard implantation. We evaluated whether inter-lead electrical delay (IED) was associated with response to CRT in these patients. We prospectively included 160 consecutive patients undergoing CRT. Pre-implant speckle-tracking echocardiography radial strain and 99mTc myocardial perfusion imaging determined the latest mechanically activated non-scarred myocardial segment. We measured procedural IED as the time interval between sensed signals in right ventricular and LV lead electrograms. All patients had LV pacing site concordant or adjacent to the latest mechanically activated non-scarred segment verified by cardiac computed tomography. Response to CRT was defined as ≥15% reduction in LV end-systolic volume at 6 months follow-up. Selecting a practical IED cut-off value of 100 ms, more patients with long IED than patients with short IED responded to CRT (87 vs. 68%; P = 0.004). In multivariate logistic regression analysis, IED ≥100 ms remained associated with CRT response after adjusting for baseline characteristics, including QRS duration and scar burden [odds ratio 3.19 (1.24-8.17); P = 0.01]. Categorizing IED by tertiles, CRT response improved with longer IED (P = 0.03). Comparable response rates were observed in patients with a concordant and adjacent LV lead position. A longer IED was associated with more pronounced LV reverse remodelling response in CRT recipients with a presumed optimal LV lead position concordant or adjacent to the latest mechanically activated non-scarred segment.

Cardiac resynchronization therapy – A comparison of VV delay optimization by 3D echocardiography using systolic dyssynchrony index and QRS width assessment at 6 months after CRT implantation

AimThe aim of this study was to compare the setting of interventricular (VV) delay by 3D echocardiography (3DE) using systolic dyssynchrony index (SDI) versus QRS width measurement in new cardiac resynchronization therapy (CRT) recipients. We observed the impact on the reduction of left ventricle volumes and increase in volumetric responders (defined as a ≥15% reduction in left ventricular end-systolic volume (LVESv)) at the 6-month follow-up. MethodsWe included 63 patients with recently implanted CRT in this open-label, randomized trial. Patients were randomized into two groups. VV delay was set by the QRS width in the group 1 (n 31) to obtain the narrowest QRS complex and by SDI in the group 2 (n 32) to achieve the lowest possible value. We evaluated LVESv, left ventricular ejection fraction (LVEF) by 3DE, before CRT implantation and at 6-month follow-up, in all patients. We also obtained clinical parameters and the level of NT-proBNP. ResultsThe second group showed only a trend toward greater reduction of LVESv (−33±55ml vs. −48±43ml; P 0.367), increase in LVEF (+7.3±10.9% vs. +10.2±9.4%; P 0.210) and greater number of volumetric responders (14 vs. 18; P 0.612) compared with the group 1 at 6-month follow-up. There were also no significant differences in clinical outcomes and the level of NT-proBNP. ConclusionIndividual CRT optimization using SDI compared with QRS duration assessment did not reveal any significant differences in echocardiographic parameters and clinical outcomes at 6-month follow-up.

Exercise-based cardiac rehabilitation in cardiac resynchronization therapy recipients: A primer for practicing clinicians.

Cardiac resynchronization therapy (CRT) is a therapeutic option of increasing importance for chronic heart failure (CHF) and criteria for implantation now concern a large amount of patient populations. As a consequence, subjects with ongoing CRT (or immediately after CRT implantation) are more often referred to Cardiac Rehabilitation (CR) programmes, and it has been recently estimated that about one third of CHF patients attending CR in Italy currently have this kind of device. The presence of CRT represents a modulating factor for exercise prescription and monitoring, since CRT patients may be considered per se as a target group for CR. Exercise therapy (ET) increases benefits from CRT on functional capacity, and recent evidence suggests an adjuvant role of ET in improving cardiovascular prognosis also. Both aerobic endurance and resistance training activities may involve CHF patients with CRT, while the potential role of aerobic interval training needs more studies and evidence. Prescription of an ET program should be associated with information regarding device programming and possible limiting factors associated with pacing therapy, tailoring of the basic principles of ET (in terms of type of exercise, intensity and program duration) in this patient group is mandatory.

Electrocardiographic outcome of resynchronization therapy.

Cardiac resynchronization therapy (CRT) has proven efficacious in reducing or even eliminating cardiac dyssynchrony and thus improving heart failure symptoms. However, quantification of mechanical dyssynchrony is still difficult and identification of CRT candidates is currently based just on the morphology and width of the QRS complex. As standard 12-lead ECG brings only limited information about the pattern of ventricular activation, we aimed to study changes produced by different pacing modes on the body surface potential maps (BSPM). Total of 12 CRT recipients with symptomatic heart failure (NYHA II-IV), sinus rhythm and QRS width >/=120 ms and 12 healthy controls were studied. Mapping system Biosemi (123 unipolar electrodes) was used for BSPM acquisition. Maximum QRS duration, longest and shortest activation times (ATmax and ATmin) and dispersion of QT interval (QTd) were measured and/or calculated during spontaneous rhythm, single-site right- and left-ventricular pacing and biventricular pacing with ECHO-optimized AV delay. Moreover we studied the impact of CRT on the locations of the early and late activated regions of the heart. The average values during the spontaneous rhythm in the group of patients with dyssynchrony (QRS 140.5+/-10.6 ms, ATmax 128.1+/-10.1 ms, ATmin 31.8+/-6.7 ms and QTd 104.3+/-24.7 ms) significantly differed from those measured in the control group (QRS 93.0+/-10.0 ms, ATmax 79.1+/-3.2 ms, ATmin 24.4+/-1.6 ms and QTd 43.6+/-10.7 ms). Right ventricular pacing (RVP) improved significantly only ATmax [111.2+/-10.6 ms (p<0.05)] but no other measured parameters. Left ventricular pacing (LVP) succeeded in improvement of all parameters [QRS 105.1+/-8.0 ms (p<0.01), ATmax 103.7+/-7.1 ms (p<0.01), ATmin 20.2+/-3.7 ms (p<0.01) and QTd 52.0+/-9.4 ms (p<0.01)]. Biventricular pacing (BVP) showed also a beneficial effect in all parameters [QRS 121.3+/-8.9 ms (p<0.05), ATmax 114.3+/-8.2 ms (p<0.05), ATmin 22.0+/-4.1 ms (p<0.01) and QTd 49.8+/-10.0 ms (p<0.01)]. Our results proved beneficial outcome of LVP and BVP in evaluated parameters (what seems to be important particularly in the case of activation times) and revealed a complete return of activation times to normal distribution when using these CRT modalities.

Complications in recipients of cardioverter-defibrillator or cardiac resynchronization therapy: Insights from Silesian Center Defibrillator registry.

Current real-life information from all-comers registries from middle and east Europe about the incidence and type of complications during long-term follow-up of patients with cardioverters-defibrillators (ICD) and cardiac resynchronization devices-defibrillators (CRT-D) is still insufficient. The aim of the study was to assess the incidence and determinants of short- and long-term complications related to implantable ICD and CRT-D. We studied 1,105 recipients hospitalized in our center in 2009-2013, followed for a mean of 2.4 years (total of 2,652 patient-years). The independent association between ICD and CRT-D recipients' and implantation-procedures' characteristics with the incidence of complications was analyzed using multivariable Cox regression analysis. In 2-month post-procedural period, 124 (11.2%) patients developed complications. Independent predictors of short-term complications (within 2 months) were: atrial fibrillation, dual chamber ICD implantation, and use of antiplatelet therapy or coumarin. Twenty-seven (2.44%) patients experienced complications, mostly lead-related (n = 21). Independent predictors of long-term complications (2-12 months after implantation) were atrial fibrillation and dual chamber ICD implantation. Despite significant technological progress and operators' experience, the occurrence of complications in ICD and CRT-D recipients is still substantial. Majority of complications are recorded in the early post-implantation phase. Analysis of independent predictors of complications seem to be essential in helping to reduce adverse events in the future and strongly supports the need for routine follow-up.

SY6-5 - Adaptive CRT Algorithm—Reducing the Non-Responder in CRT Recipients With Left Bundle Branch Block and QRS 120–150 ms

Background: Efficacy of the cardiac resynchronization therapy (CRT) in patients with left bundle branch block (LBBB), but QRS duration of 120–150 ms is still limited. Adaptive CRT algorithm had shown to be more effective in patients with preserved AV conduction but the impact of the Adaptive CRT algorithm in patients with different QRS duration remains uncertain. Methods: Patients with LBBB and preserved AV conduction enrolled in the Adaptive CRT trial, randomized study comparing the aCRT or echo-optimized CRT (control group), were used in this analysis. Endpoints for this analysis were clinical composite score (CCS) at 6 months post-implant and time to first heart failure (HF) hospitalization or death. Results: Among the 199 patients, 80 patients (40%) had a baseline QRS of 120–150 ms. In this subgroup, a greater proportion of aCRT patients had an improved CCS (79% vs 50%) at 6 months compared to the control group (P = .03). There was also a trend toward a lower risk of death or HF hospitalization (hazard ratio: 0.53; 95% CI: 0.24–1.15; P = .10) in aCRT group compared to the control arm. In the wide QRS subgroup, the efficacy was comparable in both treatment arms. Conclusion: Adaptive CRT was associated with improved patient outcomes over echo-optimized bi-ventricular CRT in patients with preserved AV conduction, LBBB, and QRS of 120–150 ms.

Gender Differences in Cardiac Resynchronization Therapy Device Choice and Outcome in Patients ≥75 Years of Age with Heart Failure

Cardiac resynchronization therapy (CRT) is an established therapy for heart failure and can be delivered through a CRT pacemaker (CRT-P) or a CRT defibrillator (CRT-D). CRT-P devices are smaller and less expensive, have better battery longevity, and have been subject to fewer recalls and advisories but cannot deliver high-energy shocks to terminate potentially lethal ventricular arrhythmias. As published guidelines do not distinguish between CRT-P and CRT-D indications, we examined the practice of prescribing these devices in older women and men with heart failure. A total of 512 CRT recipients (age ≥75 years, 26% women, 21% CRT-P) were included in this analysis. Baseline characteristics were collected on all patients, and overall survival was compared by gender and type of CRT device implanted. Women were more likely to receive CRT-Ps than men (26% vs 19%). Men with CRT-Ps were significantly older than women with CRT-Ps and both men and women with CRT-Ds (p = 0.04). In addition, women had lower all-cause mortality compared with men (hazard ratio [HR] 0.75, confidence interval [CI] 0.58 to 0.99, p = 0.04), mainly among CRT-P recipients (HR 0.48, CI 0.26 to 0.8, p = 0.02), but this association was attenuated after adjusting for differences in patient characteristics (HR 0.56, CI 0.26 to 1.18, p = 0.13). In conclusion, women are more likely to receive CRT-Ps than men. Whether this difference is driven by patient preference or physician biases remains unclear. Women with CRT, particularly CRT-Ps, have a better overall survival than men. These differences, which may be driven by unbalanced baseline characteristics of patients or by differences in gender response to CRT, deserve further investigation.

P5480Mortality predictors of device-related infective endocarditis in cardiac resynchronization therapy recipients

P5480Mortality predictors of device-related infective endocarditis in cardiac resynchronization therapy recipients

The Incidence, Clinical Significance, and Treatment Effects of Depression in Cardiac Resynchronization Therapy Recipients

Objectives: Chronic heart failure (HF) is associated with significantly increased prevalence of depression. The aim of the study was to assess the incidence and clinical impact of depression as well as the effectiveness of depression treatment in HF patients. Methods: A prospective interventional trial included 285 consecutive cardiac resynchronization therapy recipients. Patients underwent a psychiatric examination at the time of implantation and then it was routinely repeated at 3, 6, and 12 months after the procedure, and every 6 months thereafter. One hundred and thirty-five (47.4%) patients with depression were included in the depression group, whereas the control group was comprised of 150 patients free of depression. Sixty-eight (50.4%) subjects received antidepressants (treated group), whereas the observational group had 67 (49.6%) depressed patients who refused to take antidepressants. Results: Depression remission was achieved in 51 (75.0%) patients from the treated group. Long-term mortality and HF hospitalization rates were significantly higher in the depression group than in the control group (20.7 vs. 11.3% and 32.6 vs. 19.2%, respectively). However, remission from depression was associated with a 40% reduction in the relative risk of major adverse cardiac events (MACE). Conclusions: Patients with HF and concomitant depression are at higher risk of MACE compared with those free of depression. Effective antidepressant treatment may significantly improve long-term outcomes in this population.

190Mortality predictors of device-related infective endocarditis in cardiac resynchronization therapy recipients

190Mortality predictors of device-related infective endocarditis in cardiac resynchronization therapy recipients

FUNCTIONAL MITRAL REGURGITATION AND CARDIAC RESYNCHRONIZATION THERAPY: EVOLUTION AND IMPACT ON OUTCOME

Background: The long-term outcome of changes in functional mitral regurgitation (FMR) in heart failure (HF) recipients of cardiac resynchronization therapy (CRT) is unclear. Methods: A total of 1313 patients (66±11 years, 77% male, 59% ischemic heart disease) treated with CRT were evaluated.

Improvement in left ventricular intrinsic dyssynchrony with cardiac resynchronization therapy.

Objective:Cardiac resynchronization therapy (CRT) has been shown to induce a structural and electrical remodeling; the data on whether left ventricle (LV) reverse remodeling is associated with restitution of intrinsic contraction pattern are unknown. In this study, we investigated the presence of improvement in left ventricular intrinsic dyssynchrony in patients with CRT.Methods:A total of 45 CRT recipients were prospectively studied. Dyssynchrony indexes including interventricular mechanical delay (IVMD) and tissue Doppler velocity opposing-wall delay (OWD) as well as QRS duration on 12-lead surface electrocardiogram were recorded before CRT device implantation. After 1 year, patients with chronic biventricular pacing were reprogramed to VVI 40 to allow the resumption of native conduction and contraction pattern. After 4–6 h of intrinsic rhythm, QRS duration and all echocardiographic measurements were recorded. Dyssynchrony was defined as IVMD >40 ms and OWD >65 ms. CRT response was defined by a ≥15% reduction in left ventricular end-systolic volume (LVESV) at a 12-month follow-up.Results:Thirty-two patients (71%) showed response to CRT. The native QRS duration reduced significantly from 150±12 ms to 138±14 ms (p<0.001), and dyssynchrony indexes showed a significant improvement only in responders. The mean OWD reduced from 86±37 ms to 50±29 ms (p<0.001), and the mean IVMD decreased from 55±22 ms to 28±22 ms (p<0.001) in responders. The reduction in LVESV was significantly correlated with ΔOWD (r=0.47, p=0.001), ΔIVMD (r=0.45, p=0.001), and ΔQRS (r=0.34, p=0.022).Conclusion:Chronic CRT significantly improves LV native contraction pattern and causes reverse remodeling in dyssynchrony.

Atrial high-rate episodes predict clinical outcome in patients with cardiac resynchronization therapy

Objectives. Up to 50% of patients qualified for cardiac resynchronization therapy (CRT) have documented atrial fibrillation (AF) prior to CRT-implantation. This finding is associated with worse prognosis but few studies have evaluated the importance of post-implant device-detected AF. This study aimed to assess the prognostic impact of device-detected atrial high-rate episodes (AHRE), as a surrogate for AF. Design. Data were retrospectively obtained from consecutive patients receiving CRT. Baseline clinical data and data from CRT device-interrogations, performed at a median of 12.2 months after CRT-implantation, were evaluated with regard to prediction of the composite endpoint of death, heart transplant or appropriate shock therapy. Median follow-up time was 51 months post-implant. Results. The study included 377 patients. Preoperative AF was present in 49% and associated with worse outcome. The cumulative burden of AHRE at 12 months post-implant was an independent predictor of the primary endpoint. During the first 12 months after CRT-implantation, AHRE were detected in 25% of the patients with no preoperative diagnosis of AF. This finding was not associated with worse outcome. Conclusions. In CRT recipients, the cumulative burden of AHRE during the first year of follow-up was associated with worse long-term clinical outcome. Prospective trials are needed to determine if a rhythm control strategy is to be preferred in patients with CRT.

Device-related infective endocarditis in cardiac resynchronization therapy recipients — Single center registry with over 2500 person-years follow up

AimTo assess incidence, predisposing factors and outcomes of cardiac device-related infective endocarditis (CDRIE) in patients undergoing cardiac resynchronization therapy (CRT). Methods and resultsHigh-volume, single-center cardiology database was screened to identify all CDRIE cases, based on modified Duke criteria, amongst 765 consecutive CRT implantations between 2002 and 2015 (70.8% de novo implantations, 13.7% and 15.5% up-grades from pacemaker and implantable cardioverter–defibrillator [ICD], respectively).During the median follow-up (FU) of 1207days (range: 256–2664) overall 38 CDRIE (4.97%) cases were identified (incidence: 15/1000 person-years). Multivariate Cox regression model, incorporating significant baseline differences as covariates (model 1), demonstrated that both up-grade from ICD to CRT and higher baseline NYHA class were independently associated with increased risk of CDRIE (adjusted HR 4.29, 95%CI 1.93–9.57; and HR 2.43, 95%CI 1.32–4.49, respectively). In the second model (including all differences with P<0.2) up-grade from ICD (HR 4.36, 95%CI 1.96–9.69), higher NYHA class (HR 2.04, 95%CI 1.11–3.75), hypertrophic cardiomyopathy (HR 5.85, 95% CI 1.46–23.52), lower baseline hemoglobin level (HR 0.68, 95%CI 0.50–0.94) and chronic obstructive pulmonary disease (HR 2.46, 95%CI 1.05–5.77) were all independently associated with higher risk of CDRIE. All-cause mortality in patients with CDRIE was significantly higher than in subjects without infective complications (68.4% vs. 33.7%, P<0.001), and 50% of patients with CDRIE died during index hospitalization. ConclusionsThe prevalence of CDRIE in CRT recipients is almost 5% within 3.5years post implantation. Up-grade from ICD and high baseline NYHA class flag up patients at high-risk of CDRIE. CRT-related infective complications are associated with very poor prognosis.

Lead related complications in quadripolar versus bipolar left ventricular leads

BackgroundQuadripolar left ventricular (LV) leads are capable of pacing from four different electrodes which allows for easier and more stable intra-operative lead positioning with optimal pacing parameters. We therefore investigated the rate of combined intra-operative and post-operative LV lead related events in quadripolar vs. bipolar LV lead cardiac resynchronization therapy (CRT) recipients in the real world setting. MethodsWe retrospectively collected data for N = 1441 patients at our institution implanted with quadripolar (n = 292) or bipolar (n = 1149) LV leads from 2012 to 2014 and followed them to the primary end-point of composite lead outcome defined as intra-operative lead implant failure or post-operative lead dislodgement or deactivations. ResultsPatients implanted with a quadripolar lead were younger (70.6 ± 11.4 vs 72.5 ± 11.6, p = 0.014) and had higher incidence of diabetes (41.8% vs 32.8%, p = 0.004) compared to those with bipolar leads. All other baseline characteristics were comparable. Patients implanted with a quadripolar were significantly less likely to reach the primary endpoint in the first 12 months after LV lead implantation (Hazard Ratio 0.22, 95% Confidence Interval 0.08–0.60, p = 0.001). There were no differences between the two groups in rates of hospitalization for any cause or in mortality. ConclusionIn this real world study, quadripolar LV leads have significantly lower rates of implantation failure and post-operative lead dislodgement or deactivation. These results have important clinical implications to CRT recipients.