Cardiac Resynchronization Therapy Pacemaker Research Articles

Is ventricular sensing always right, when it is left?

Ventricular sensing in transvenous cardiac implantable electronic devices (CIEDs) occurs conventionally from the right ventricular (RV) channel, though it evolved from epicardial sensing both in pacemakers and implantable cardioverter-defibrillators (ICDs). The objective of this study was to observe the reliability of left ventricular (LV) sensing by transvenous leads placed in coronary veins. LV leads were used for sensing and arrhythmia detection in clinical situations where placement of an RV lead across the tricuspid valve was either not preferred or not feasible, or RV signal was unsuitable for arrhythmia detection, or in the event of sensing failure of an RV lead under advisory in cardiac resynchronization therapy defibrillator (CRTD) recipients. Thirty-seven patients had an IS-1 LV lead connected to the RV port of CIEDs (17 pacemakers, 5 cardiac resynchronization therapy pacemaker [CRTP], 2 ICDs, and 13 CRTDs). Along a median 41 (25-67) months follow-up, lead performance remained stable; there were neither undersensing nor oversensing of non-cardiac signals. VT/VF were correctly detected and terminated by ATP and shocks (one and three patients, respectively); no inappropriate arrhythmia detection. Device reprogramming occurred in four CRTD recipients because of transient counting the QRS (short intervals) when paced in LV-only, and in two with T-wave oversensing. Ventricular sensing by an LV lead is feasible in transvenous devices. Sensing programmability is an unmet need: to fix RV lead sensing issues in cardiac resynchronization therapy (CRT) recipients at no risk of infection (no pocket opening); to avoid interaction with the tricuspid valve; to avoid lead redundancy in the vasculature. Moreover, it will be mandatory owing to the loss of lead interchangeability due to the adoption of DF-4 and quadripolar leads.

Cardiac resynchronization therapy pacemakers versus defibrillators in older non-ischemic cardiomyopathy patients

IntroductionWith the recent publication of the negative DANISH trial, the mortality benefit of the implantable cardioverter-defibrillator (ICD) has been put in question in patients with non-ischemic cardiomyopathy (NICM). Because a majority of patients in DANISH receive cardiac resynchronization therapy (CRT) devices, we investigated in the present study the survival of recipients of CRT pacemakers (CRT-P) versus CRT ICDs (CRT-D) in a cohort of older (≥75 years) NICM patients at our institution. MethodsA total of 135 NICM patients with CRT device were identified (42 with CRT-P and 93 with CRT-D) and were followed to the endpoint of all-cause mortality. Overall survival was compared between the CRT-P and CRT-D groups with adjustment for differences in baseline characteristics. ResultsOver a median follow-up of 46 months from the time of CRT device implantation, there were 54 total deaths (40%): 14 in the CRT-P (33%) and 40 in the CRT-D (43%) groups. Overall, CRT-P recipients had similar unadjusted mortality compared to CRT-D recipients (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.56–1.93), and this remained unchanged after adjusting for unbalanced covariates (HR 0.95, 95% CI 0.47–1.89) including left ventricular ejection fraction, used of angiotensin converting enzyme inhibitors/angiotensin receptor blockers, and the Charlson comorbidity index. ConclusionOur data support that in older NICM patients with CRT devices, the addition of ICD therapy does not improve survival.

Candidacy for a Subcutaneous Implantable Cardioverter Defibrillator in Patients with Cardiac Resynchronization Therapy.

In patients requiring an implantable cardioverter defibrillator (ICD), the combined use of a prior pacemaker and a subcutaneous ICD (S-ICD) could be an alternative treatment option to implantation of new leads or upgrading of pacemakers to an ICD if vascular access is limited. Here, we assessed the prevalence of S-ICD's eligibility according to surface electrogram screening in those receiving cardiac resynchronization therapy (CRT). S-ICD's eligibility was assessed in patients with a CRT pacemaker or a CRT defibrillator using the S-ICD template screening tool. Eligibility was defined as fulfillment of the template in both supine and upright positions in one or more leads during biventricular pacing. Among 44 patients (34 men, age: 67 ± 12), 36 (82%) were found to be eligible. The T/QRS amplitude ratio in lead II was significantly lower in those who were eligible (0.31 ± 0.16 versus 0.44 ± 0.18 in the ineligible group, P = 0.04). The lead position, underlying disease, and other electrocardiographic findings were not different between those who were eligible and those who were not. The majority of patients with biventricular pacing were eligible for S-ICD based on current screening tests and may benefit from this treatment. Further study is required.

Cardiac resynchronization therapy in the ageing population – With or without an implantable defibrillator?

BackgroundCardiac resynchronization therapy (CRT) is an effective treatment option for systolic heart failure, but the benefit of an additional implantable cardioverter-defibrillator (ICD) in elderly patients is not well established. The aim of our study was to evaluate the impact of an additional ICD on survival in elderly CRT recipients. MethodsPatients aged ≥75 years with an indication for CRT and primary preventive ICD therapy, which underwent implantation of either a CRT-pacemaker (CRT-P) or CRT-defibrillator (CRT-D) were included in the study. Patient characteristics, procedural and follow-up data, and subsequent all-cause mortality were analyzed. ResultsA total of 775 consecutive patients underwent CRT implantation, whereof 177 patients fulfilled the inclusion criteria. Of these, 80 patients with CRT-P and 97 with CRT-D formed the two study groups. Patients in the CRT-P group were significantly older (82.6 ± 4.5 vs. 77.8 ± 1.9 years, p < 0.001) and more often female (44 vs. 25%; p < 0.001), had a better left ventricular ejection fraction (29.5 ± 5.7 vs. 27.4 ± 6.0%; p = 0.019) and narrower QRS-complex (150 ± 19 vs. 158 ± 18 ms; p = 0.025). During a mean follow-up of 26 ± 19 months, 62 (35%) study patients died, 28 (35%) in the CRT-P and 34 (35%) in the CRT-D group (p = 0.994). The Kaplan-Meier analysis of survival probability showed no significant difference between the two groups (p = 0.562). ConclusionIn our study, an additional ICD had no impact on survival in elderly patients undergoing implantation of a CRT device. Randomized controlled trials have to confirm this finding.

Indications for Cardiac Resynchronization Therapy: A Comparison of the Major International Guidelines

ObjectivesThis study compares and contrasts the recommended indications for cardiac resynchronization therapy (CRT) according to the most recent guidelines from international cardiology societies. BackgroundCRT has been shown to reduce morbidity and mortality in selected patients with systolic heart failure. Cardiology societies provide guidelines regarding the indications for CRT. As evidence evolves, it is challenging for the guideline committees to review the impact of newer evidence in a timely fashion. MethodsSix of the most recent international guidelines providing recommendation concerning CRT implantation ranging from 2011 to 2017 were reviewed. These included guidelines from 2 European, 1 North American, 1 Canadian, and 1 Australian/New Zealand societies and the National Institute for Health and Care Excellence guidelines, specific to the United Kingdom. ResultsAlthough international societies provide consistent recommendations for most CRT indications, differences are found in recommendations for several important patient populations. Specifically, divergent recommendations exist regarding QRS duration, bundle branch morphology, patients in atrial fibrillation, choice of device type (CRT pacemakers vs. CRT defibrillators), and selected patients who are likely to be dependent on right ventricular pacing. The timing of publication of specific guidelines appears to play an essential role in explaining these disparities. ConclusionsDespite general consistency in international guideline recommendations, there remain certain patient populations for whom there are variations in recommendations concerning eligibility for CRT and selection of the most appropriate device in the individual patient.

COMPARISON BETWEEN CARDIAC RESYNCHRONIZATION THERAPY WITH AND WITHOUT DEFIBRILLATOR ON LONG-TERM MORTALITY: A PROPENSITY SCORE MATCHED ANALYSIS

Cardiac resynchronisation therapy (CRT)-defibrillator (CRT-D) has been widely used over CRT-pacemaker (CRT-P) in patients of heart failure with reduced ejection fraction (HFrEF) and prolong QRS duration. However, the superiority of CRT-D over CRT-P to reduce mortality has not been systematically

Case presentation: implantation of cardiac resynchronization therapy pacemaker via the coronary sinus in a patient with triple valve replacement

BackgroundIn patients with triple valve replacement developing third-degree atrioventricular block (AVB), the most appropriate approach for permanent pacemaker implantation remains questionable.Case presentationIn this case presentation, we first described the approach of implantation of the cardiac resynchronization therapy pacemaker (CRT-P) via one bipolar pacing lead in middle cardiac vein (MCV) and one quadripolar pacing lead in anterior interventricular vein (AIV) in a patient developing complete AVB, who had been previously diagnosed with rheumatic valvular heart disease with triple valve replaced. After the CRT-P implantation, the two pacing leads in coronary sinus (CS) provided a dual-site ventricular pacing from the anterior septum and posterior septum, which resulted in a narrow QRS complex and an increased ventricular synchrony. During the long-term follow-up, no deterioration of heart function was documented and pacing parameters remained good.ConclusionIn this patient developing complete AVB with triple valve replaced, our approach of CRT-P implantation provides an effective and reliable ventricular pacing, and is an alternative option when transvenous right ventricular pacing, transseptal left ventricular pacing and transpericardial epicardium pacing are not possible. Further prospective randomized trials are required to confirm the efficiency of our approach of dual-site ventricular pacing by CRT-P in this kind patients.

Oversensing of transthoracic excitation stimuli in contemporary pacemakers.

Transthoracic impedance measurements (TIM) is primarily used for minute ventilation rate adaptive sensors in pacemakers. With elevated impedance, the TIM electrical signal itself is oversensed, causing device malfunction. We report an increased incidence of TIM oversensing. Retrospective chart review. We review existing records of 18 patients who have demonstrated device malfunction with TIM oversensing. We have found a 1.8% incidence of TIM-related oversensing in our patient population of 959 patients with contemporary Boston Scientific (Marlborough, MA, USA) pacemakers and cardiac resynchronization therapy pacemakers. One patient experienced a syncopal episode. Oversensing with pacing inhibition is apparent with the potential of adverse effects to patients.

Clinical impact of implantable cardioverter-defibrillator in primary prevention of total mortality in non-ischaemic cardiomyopathy: results from a meta-analysis of prospective randomized clinical trials.

Primary prophylactic implantable cardioverter defibrillators (ICDs) have demonstrated a clear all-cause mortality benefit in patients with ischaemic cardiomyopathy, with less compelling evidence supporting its use in patients with non-ischaemic cardiomyopathy (NICM). We performed a meta-analysis of randomized controlled trials (RCTs) evaluating the role of ICD for reduction in total mortality in NICM patients. An electronic search on PubMed, the Cochrane Library, and EMBASE databases was performed to identify the RCTs evaluating the role of prophylactic ICD placement in NICM patients. Mantel-Haenszel risk ratio (RR) fixed-effects model was used to summarize data across treatment arms. Random-effects model was used if heterogeneity (I2) ≥ 25. Patients with cardiac resynchronization therapy pacemaker (CRT-P) were included in the control group. Six RCTs, with a total of 3128 patients and a mean follow-up period of 48 ± 22 months comparing ICD with medical therapy in NICM were included in this analysis. There was a significant reduction in all-cause mortality in the ICD group compared with the medical therapy group [RR 0.79, 95% confidence interval (95% CI) 0.68-0.92; P = 0.002]. No publication bias was noted. Currently available evidence demonstrates that the use of ICD provides a clear and significant reduction in all-cause mortality among patients with NICM.

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.

Scar Characterization to Predict Life-Threatening Arrhythmic Events and Sudden Cardiac Death in Patients With Cardiac Resynchronization Therapy: The GAUDI-CRT Study

ObjectivesThe aim of this study was to analyze whether scar characterization could improve the risk stratification for life-threatening ventricular arrhythmias and sudden cardiac death (SCD). BackgroundAmong patients with a cardiac resynchronization therapy (CRT) indication, appropriate defibrillator (CRT-D) therapy rates are low. MethodsPrimary prevention patients with a class I indication for CRT were prospectively enrolled and assigned to CRT-D or CRT pacemaker according to physician’s criteria. Pre-procedure contrast-enhanced cardiac magnetic resonance was obtained and analyzed to identify scar presence or absence, quantify the amount of core and border zone (BZ), and depict BZ distribution. The presence, mass, and characteristics of BZ channels in the scar were recorded. The primary endpoint was appropriate defibrillator therapy or SCD. Results217 patients (39.6% ischemic) were included. During a median follow-up of 35.5 months (12 to 62 months), the primary endpoint occurred in 25 patients (11.5%) and did not occur in patients without myocardial scar. Among patients with scar (n = 125, 57.6%), those with implantable cardioverter-defibrillator (ICD) therapies or SCD exhibited greater scar mass (38.7 ± 34.2 g vs. 17.9 ± 17.2 g; p < 0.001), scar heterogeneity (BZ mass/scar mass ratio) (49.5 ± 13.0 vs. 40.1 ± 21.7; p = 0.044), and BZ channel mass (3.6 ± 3.0 g vs. 1.8 ± 3.4 g; p = 0.018). BZ mass (hazard ratio: 1.06 [95% confidence interval: 1.04 to 1.08]; p < 0.001) and BZ channel mass (hazard ratio: 1.21 [95% confidence interval: 1.10 to 1.32]; p < 0.001) were the strongest predictors of the primary endpoint. An algorithm based on scar mass and the absence of BZ channels identified 148 patients (68.2%) without ICD therapy/SCD during follow-up with a 100% negative predictive value. ConclusionsThe presence, extension, heterogeneity, and qualitative distribution of BZ tissue of myocardial scar independently predict appropriate ICD therapies and SCD in CRT patients.

Implantable cardioverter defibrillator in non-ischemic cardiomyopathy: a meta-analysis of randomized controlled trials.

Sudden cardiac death (SCD) is a significant cause of mortality in patients with non-ischemic cardiomyopathy (NICM). Implantable cardioverter defibrillators (ICDs) are currently indicated for the primary prevention of SCD in these patients. Conflicting results from published randomized controlled trials (RCTs) have recently questioned the protective role of ICD in NICM patients to perform an updated meta-analysis of the effect of ICDs on outcomes of NICM patients. We performed a search of PubMed, EMBASE, and Cochrane databases for RCTs comparing ICD to medical therapy in patients with NICM. Outcomes were all-cause mortality, SCD, and cardiac mortality. Mantel-Haenszel (MH) risk ratios (RR) were calculated using random-effects meta-analysis for the outcomes mentioned. Heterogeneity was assessed using I2 statistics and Q-statistic. A total of five RCTs met the inclusion criteria, with a total of 1,503 patients in the ICD group and 1,364 patients in the medical therapy. Compared to medical therapy, ICD use resulted in a 24% relative risk reduction (RRR) of all-cause mortality (RR 0.76, 95% CI 0.64-0.91, P=0.002), and 60% RRR of SCD (RR 0.40, 95% CI 0.18-0.90, P=0.03), but was not associated with a statistically significant benefit in the prevention of cardiac mortality (RR 0.75, 95% CI 0.39-1.44, P=0.39). Limiting the analysis to patients who received an ICD only without cardiac resynchronization therapy (CRT) pacemakers (4 trials, 1,825 patients) showed similar all-cause mortality results with 24% RRR in ICD group (RR 0.76, 95% CI 0.61-0.94, P=0.01). ICD therapy reduces all-cause mortality and SCD in patients with NICM.

Incremental benefit of cardiac resynchronisation therapy with versus without a defibrillator

ObjectiveTo determine the incremental value of implantable cardioverter defibrillators (ICD) in contemporary optimally treated patients with heart failure (HF) undergoing cardiac resynchronisation therapy (CRT).MethodsConsecutive patients with HF undergoing CRT-pacemaker (CRT-P)...

P1526Interventricular delay and left ventricular delay in right ventricular pacemaker pacing before upgrading to biventricular pacing

Background: Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy for heart failure (HF) patients (P) with sinus rhythm, reduced left ventricular (LV) ejection fraction (EF) and electrical ventricular desynchronization. The aim of the study was to evaluate electrical interventricular delay (IVD) and left ventricular delay (LVD) in right ventricular (RV) pacemaker pacing before upgrading to CRT BV pacing. Methods: HF P (n=11, age 69.0 ± 7.9 years, 1 female, 10 males) with DDD pacemaker (n=10), DDD defibrillator (n=1), RV pacing, New York Heart Association (NYHA) class 3.0 ± 0.2 and 24.5 ± 4.9 % LVEF were measured by surface ECG and transesophageal bipolar LV ECG before upgrading to CRT defibrillator (n=8) and CRT pacemaker (n=3). IVD was measured between onset of QRS in the surface ECG and onset of LV signal in the transesophageal ECG. LVD was measured between onset and offset of LV signal in the transesophageal ECG. CRT atrioventricular (AV) and BV pacing delay were optimized by impedance cardiography. Results: Interventricular and intraventricular desynchronization in RV pacemaker pacing were 228.2 ± 44.8 ms QRS duration, 86.5 ± 32.8ms IVD, 94.4 ± 23.8ms LVD, 2.6 ± 0.8 QRS-IVD-ratio with correlation between IVD and QRS-IVD-ratio (r=-0.668 P=0.0248) and 2.3 ± 0.7 QRS-LVD-ratio. The LVEF-IVD-ratio was 0.3 ± 0.1 with correlation between IVD and LVEF-IVD-ratio (r=-0.8063 P=0.00272) and with correlation between QRS duration and LVEF-IVD-ratio (r=-0.7251 P=0.01157). Optimal sensing and pacing AV delay were 128.3 ± 24.8 ms AV delay after atrial sensing (n=6) and 173.3 ± 40.4 ms AV delay after atrial pacing (n=3). Optimal BV pacing delay was -4.3 ± 11.3 ms between LV and RV pacing (n=7). During 30.4 ± 29.6 month CRT follow-up, the NYHA class improved from 3.1 ± 0.2 to 2.2 ± 0.3. Conclusions: Transesophageal electrical IVD and LVD in RV pacemaker pacing may be additional useful ventricular desynchronization parameters to improve P selection for upgrading RV pacemaker pacing to CRT BV pacing.

18 Upgrade to defibrillator in patients receiving cardiac resynchronisation therapy pacemakers

IntroductionIn patients with advanced cardiac failure, the choice between CRT with (CRT-D) or without a defibrillator (CRT-P), remains a contentious issue. There is insufficient evidence from randomised controlled trials and...

Clinical decision tool for CRT-P vs. CRT-D implantation: Findings from PROSE-ICD.

BackgroundCardiac resynchronization therapy (CRT) devices reduce mortality through pacing-induced cardiac resynchronization and implantable cardioverter defibrillator (ICD) therapy for ventricular arrhythmias (VAs). Whether certain factors can predict if patients will benefit more from implantation of CRT pacemakers (CRT-P) or CRT defibrillators (CRT-D) remains unclear.Methods and resultsWe followed 305 primary prevention CRT-D recipients for the two primary outcomes of HF hospitalization and ICD therapy for VAs. Serum biomarkers, electrocardiographic and clinical variables were collected prior to implant. Multivariable analysis using Cox-proportional hazards model was used to fit the final models. Among 282 patients with follow-up outcome data, 75 (26.6%) were hospitalized for HF and 31 (11%) received appropriate ICD therapy. Independent predictors of HF hospitalization were atrial fibrillation (HR = 1.8 (1.1,2.9)), NYHA class III/IV (HR = 2.2 (1.3,3.6)), ejection fraction <20% (HR = 1.7 (1.1,2.7)), HS-IL6 >4.03pg/ml (HR = 1.7 (1.1,2.9)) and hemoglobin (<12g/dl) (HR = 2.2 (1.3,3.6)). Independent predictors of appropriate therapy included BUN >20mg/dL (HR = 3.0 (1.3,7.1)), HS-CRP >9.42mg/L (HR = 2.3 (1.1,4.7)), no beta blocker therapy (HR = 3.2 (1.4,7.1)) and hematocrit ≥38% (HR = 2.7 (1.03,7.0)). Patients with 0–1 risk factors for appropriate therapy (IR 1 per 100 person-years) and ≥3 risk factors for HF hospitalization (IR 23 per 100-person-years) were more likely to die prior to receiving an appropriate ICD therapy.ConclusionsClinical and biomarker data can risk stratify CRT patients for HF progression and VAs. These findings may help characterize subgroups of patients that may benefit more from the use of CRT-P vs. CRT-D systems.Trial registrationClinicalTrials.gov NCT00733590

Implantation of cardiac resynchronization therapy devices using three leads by cephalic vein dissection approach.

Percutaneous subclavian, axillary, and cephalic vein access are all used in conjunction for atrial and ventricular lead implantation, though no standard approach for cardiac resynchronization therapy (CRT) device implantation has been established. We describe an effective and a safe technique for implanting three leads via cephalic vein for CRT pacemaker and/or defibrillator implantations. A total of 171 consecutive patients undergoing de novo implantation of CRT pacemaker or defibrillator were included. Cephalic vein access was achieved by dissection and direct visualization. If the cephalic vein was inadequate, alternate means of access was determined after outset of the procedure. Procedural success rates and complications were recorded. Of the 171 de novo CRT implant attempts, 169 (98.8%) patients had successful implantation of all 3 leads on the first attempt. Of the 171 procedural attempts, 150 (87.7%) patients had all 3 leads placed via cephalic vein. Overall, complications occurred in 6 of 171 patients (3.5%) including initial and repeat procedures. These complications included seven lead dislodgements, two cases of diaphragmatic stimulation requiring lead revision, and one coronary sinus dissection without pericardial effusion. There were no cases of pneumothorax, pocket haematoma requiring evacuation, or infection. The triple lead via cephalic vein technique is safe and effective when used as a first approach for CRT device implantation.

Utilization and in-hospital complications of cardiac resynchronization therapy: trends in the United States from 2003 to 2013.

Cardiac resynchronization therapy (CRT) device implantation has been shown to reduce morbidity and mortality in selected patients with heart failure. We sought to investigate the utilization and in-hospital complications of cardiac resynchronization therapy defibrillator (CRT-D) and pacemaker (CRT-P) implantations in the United States from 2003 to 2013. Patients receiving CRT-D or CRT-P were identified in the National Inpatient Sample database (NIS), using the International Classification of Diseases-Ninth Revision-Clinical Modification procedure codes. Annual implantation rates, patient demographics, co-morbidities, in-hospital complications, and length of stay were analysed. From 2003 to 2013, an estimated total of 439010 (95% CI: 406723-471296) inpatient CRT implantations were performed in the U.S. The median age of patients was 72 and 71% were male. Overall, 6.1% had at least one complication. During the study period, comorbidity index and overall complication rate increased (P = 0.002 and P = 0.01, respectively). Mortality and length of stay showed no significant trend. Predictors of complications included: age 65 and older, female sex (OR: 1.19; 95% CI: 1.12-1.27), Deyo-Charlson Comorbidity Index, and elective admission (OR: 0.61; 95% CI: 0.57-0.66). From 2003 to 2013, the severity of comorbid conditions increased and a rising trend was observed in the rate of periprocedural complications among patients undergoing CRT in the United States. In-hospital mortality and length of stay showed no uniform trend.

HIGH BATTERY IMPEDANCE IN THE PACEMAKER DEPENDENT PATIENT: EARLY RECOGNITION AND COLLABORATIVE MANAGEMENT OF INSYNC III CRT-P DEVICE FAILURES

Background: This abstract presents a series of pacemaker dependent patients who experienced unexpected high battery impedance leading to device failure of the Medtronic® InSync III Cardiac Resynchronization Therapy Pacemaker (CRT-P model 8042B) which prompted a Class II FDA recall in November 2015

ECG score to predict ICD therapies in patients with nonischemic cardiomyopathy and primary prophylactic CRT-D

Recently published results of the DANISH study raise concerns, if primary prophylactic ICD implantations in patients with nonischemic cardiomyopathy (NICM) and severe reduced left ventricular ejection fraction (LVEF) should be performed without further risk stratification. There was no significant difference in the overall mortality of patients with or without ICD and CRT defibrillator (CRT-D) or CRT pacemaker (CRT-P), respectively. Clinical risk scores to identify patients with ischemic cardiomyopathy (ICM) who benefit most from an ICD have been recommended. The need for risk stratification systems concerning patients with NICM has been emphasized. A retrospective study of 434 consecutive patients with CRT-D implantation was performed. Patients with no regular follow-up at our institution (n= 132), secondary prophylactic ICD indication (n= 61), and upgrade to CRT (n= 95) were excluded. The occurrence of an adequate ICD therapy was defined as the endpoint. Left ventricular ejection fraction (LVEF), genesis of the cardiomyopathy as well as the modified Selvester ECG score (MSES) for evaluation of the left ventricular scar burden were documented among other characteristics. Within a median follow-up of 605 days, 24% of the patients experienced an adequate ICD therapy. These patients had significantly lower LVEF (20% vs. 23%), and the MSES was higher (7 vs. 3points). There was no significant difference in patients suffering from ICM vs NICM. Areceiver-operating-characteristic (ROC) analysis revealed asensitivity of 0.914 and aspecifity of 0.586 for MSES ≥4 to predict the occurrence of an ICD therapy. None of 35patients suffering from NICM with MSES <4 experienced an ICD therapy. The evaluation of the left ventricular scar burden using MSES can be useful for the decision between CRT-D and CRT-P in patients suffering from NICM.