Cardiac Resynchronization Therapy Group Research Articles

Abstract 4137113: The Effectiveness of Cardiac Resynchronization Therapy in Patients with Cardiac Sarcoidosis: A Retrospective Analysis

Background: Cardiac sarcoidosis (CS) manifests in a wide range of clinical presentations, including conduction system abnormalities, ventricular arrhythmias, and systolic heart failure. Although cardiac resynchronization therapy (CRT) has shown efficacy in treating select nonischemic cardiomyopathy patients, its specific impact on CS patients remains less explored. This study aimed to evaluate the outcomes of CRT therapy in CS patients, focusing on implantable cardioverter defibrillator (ICD) therapies, heart failure (HF) hospitalizations and mortality. Methods: We retrospectively reviewed all patients with a clinical or histological diagnosis of CS who underwent device implantation (ICD or Permanent Pacemaker (PPM)) with or without CRT therapy at Johns Hopkins Hospital between 2004 and 2024. Baseline characteristics and echocardiographic parameters were assessed. Heart failure hospitalizations, the frequency of ATP (Anti-Tachycardia Pacing) or ICD shocks, and all-cause mortality were also evaluated as the outcomes. Results: The study included 212 patients (40.1% female, average age 52.8 ± 11.1 years). Eighty-five patients underwent CRT implantation (82 CRT-D and 3 CRT-P), whereas the rest received either an ICD or a PPM without CRT therapy. Most CRT devices (58.82%) were upgrades from an initial PPM or ICD. Over a follow-up of 6.15 ± 4.43 years, 27 (12.74%) patients were hospitalized for heart failure (HF), 86 (40.56%) experienced ATP or ICD shocks, and 17 (8.02%) died. The composite outcome was observed in 103 patients (48.5%), with no significant differences between CRT and non-CRT groups ( P = .51). Survival analysis indicated significantly reduced freedom from HF hospitalizations in the CRT group compared to non-CRT group ( P = .01). However, ATP/ICD shocks did not have a significant difference. CRT recipients showed an improvement in left ventricular ejection fraction (LVEF) from 35.3 ± 12.6% to 38.9 ± 13.6% at 6 months ( P = .01). Non-recipients showed no significant change in LVEF ( P = .43). Conclusions: Over an average six-year follow-up period, CRT upgrade does not appear to affect ATP/ICD shock and mortality in CS patients, although it is associated with significantly higher rates of heart failure (HF) hospitalizations compared to CS patients with an ICD or PPM alone. These findings underscore the complex response of CS patients to CRT, highlighting the need for further research to optimize treatment strategies within this subgroup.

CRT should be recommended for all heart failure patients with mechanical dyssynchrony and a ventricular conduction delay regardless of the QRS morphology

Abstract Introduction Two recent meta-analyses displayed the heterogeneous effect of cardiac resynchronization therapy (CRT) in patients with a non-left bundle branch block (non-LBBB) and found an increased burden of ventricular arrhythmias after CRT (1,2). Careful patient selection is therefore paramount. Evidence suggests the assessment of mechanical dyssynchrony may guide decision-making to CRT in this challenging population. Purpose To assess the effect of CRT in patients with and without mechanical dyssynchrony compared to medication only, and in particular in patients with a non-LBBB morphology. Methods We retrospectively screened for symptomatic heart failure patients who presented between 2012 and 2018 at our clinic with a QRS duration ≥130ms and a left ventricular ejection fraction (LVEF) ≤35%. We identified 361 patients who received CRT and 1107 patients who could have been considered for CRT. Patients were excluded if echocardiographic data was unavailable, they received CRT after 2018, were 80 years or older, or had other significant co-morbidities. We enrolled the remaining 220 CRT patients ("CRT") and 124 patients treated with medication only ("Control") for analysis. Patients were categorized for the presence of mechanical dyssynchrony on echocardiography, defined as the presence of either septal flash, apical rocking, or both. Multivariable-adjusted Cox regression analyses, including stratification by the presence of dyssynchrony, was performed to compare the effect of CRT to medication only. Hazard ratios (aHR) were obtained after adjustment for age, sex, atrial rhythm, QRS duration, QRS morphology, ischemic disease, kidney function, medication and presence of a defibrillator. Sensitivity analysis was performed in patients with a non-LBBB morphology. Results The CRT and Control group were comparable except for the QRS duration (163±22ms vs 152±16ms, p<0.001), the proportion of patients on optimal medical therapy (64% vs 47%, p=0.001), patients with a defibrillator (81% vs 19%, p<0.001), and patients with a LBBB morphology (75% vs 47%, p<0.001). During an average follow-up of 6.0(±3.2) years, 162 patients (47%) died. In the overall cohort, CRT did not significantly improve survival (aHR: 0.66, p=0.065). There was, however, a marked survival benefit for CRT over medication only in patients with mechanical dyssynchrony (aHR: 0.37, p=0.001). In patients without dyssynchrony there was a trend towards harm due to CRT (aHR: 2.05, p=0.062). These results were consistent in the sub-cohort of patients with a non-LBBB morphology. Conclusion CRT significantly improves the life expectancy of patients with mechanical dyssynchrony, including patients with a non-LBBB morphology. These results add to the evidence that all heart failure patients with LVEF≤35%, QRS≥130ms and mechanical dyssynchrony should be recommended (Class I) for CRT regardless of QRS morphology, while awaiting the results of ongoing randomized controlled trials.

Comparative study of the effects of preferential left ventricular and biventricular pacing on echocardiographic and cardiorespiratory indices and clinical status of heart failure patients: preliminary

Abstract Introduction Nonresponse to cardiac resynchronization therapy (CRT) has been related with right ventricular dysfunction. Preferential left ventricular pacing (pLV-P) can achieve left ventricle resynchronization allowing for intrinsic activation of the right side, and benefit cardiac output while reducing atrial fibrillation occurrence. Moreover, the AdaptivCRT® algorithm also automatically adjusts interventricular (V-V) delay every minute. Methods We evaluated the effects of a pLVP algorithm on 100 systolic heart failure patients ( all Caucasians, 49% male; 67 +/- 8 years old; 51% ischemic cardiomyopathy; 44% diabetics; NYHA II-III) following randomization to standard biventricular pacing and pLVP, on echocardiographic and cardiopulmonary exercise test indices of functional status. Device programming was based on echocardiography-evaluated maximization of stroke volume and subsequent interventricular and atrioventricular delay adjustments delegated to the device. The follow-up consisted of 6 and 12-months visits; after the 1rst month of optimizing maximum CRT response. Results Significant comparative effects of pLV-P over optimized CRT were noted regarding right ventricle systolic velocity in TDI at 12-months from baseline (mean (SE); 4.5(0.8), p=0.035); decrease in end-diastolic volume of left ventricle (mean (SE); 11.33(7), p=0.035); decrease in right ventricle strain mean ((SE); 9.2(2.1), p=0.03). According to other echocardiographic indices, again taking into account baseline levels, patients in pLV-P group exhibited lower E/e value at 6-months (mean (SE); 8.390(4,3), p=0.04), and at 12 -months (mean (SE); 7.45(3.9), p=0.035); improved values in left atrium contractility strain at 12-months (mean (SE); 8.390(0.8), p=0.04); a borderline improvement in left ventricular ejection fraction (mean (SE); 8.7(433), p=0.05) at 12-months; and borderline improvement in left ventricular longitudinal strain at 6-months (mean (SE); 4.9(2.6), p=0.035), compared to optimized CRT. In CPET, taking into account baseline levels, patients in the pLVP group showed higher METs at 12-months (mean (SE); 1,16(0.8), p=0.03) compared to opt CRT group; higher predicted Ventilation rate (%) even from 6-months (mean (SE); 8.167(5,7), p=0.03) and higher predicted peak VO2 (%) at 6 months (mean (SE); 34,13(14), p=0.03) and borderline significance at 12 months (mean (SE); 4.88(3), p=0.08), compared to opt CRT. Conclusions In the preliminary findings of READAPT study, it seems that pLVP optimized by a standardized echocardiographic protocol in patients with preserved AV conduction and LBBB, can achieve improvement in parameters of right ventricular and left atrium structure and function, as well as in survival-predictive parameters of CPET compared to optimized CRT during the 12-months of follow-up.

Left bundle branch block cardiomyopathy (LBBB-CMP): from the not-so-benign finding of idiopathic LBBB to LBBB-CMP diagnosis and treatment.

two main objectives: (1) to explore the natural history of "asymptomatic" iLBBB carriers; (2) to characterize the outcomes and therapeutic approach used in a "real-world" cohort of possible LBBB-CMP patients (pts). tertiary care centre retrospective study of pts with iLBBB and possible LBBB-CMP, screened from a large hospital electrocardiographic database from 2011 to 2017 (LBBB = 347). To assign the 1st objective, only pts with left ventricular ejection fraction (LVEF) ≥ 50% and available follow-up (FU) data were included (n = 152). Regarding the 2nd objective, possible LBBB-CMP pts were selected and defined as iLBBB pts with LVD (LVEF < 50%) and no secondary causes for LVD (n = 53). Data were based on pts' careful review of medical records. focusing our 1st objective, 152 iLBBB carriers were identified. Median FU time were 8years, and 61% were female. During FU, approximately 25% developed LVD, 20% needed ≥ 1 cardiovascular (CV) hospitalization, and 15% needed a cardiac device implantation. The majority (2/3) of pts with LVD on FU (n = 35) had no secondary causes for LVD, being classified as possible LBBB-CMP pts. Time-to-LVD analysis showed no differences between pts with a known cause for LVD vs LBBB-CMP pts (Log-rank = 0.713). Concerning the 2nd objective, 53 possible LBBB-CMP pts were identified. Median FU time were 10years, and 51% were female. During the FU, 77% presented heart failure (HF) symptoms, and 42% needed ≥ 1 CV hospitalization, mainly due to HF. Half presented severe LVD at some point in time, and 55% needed a cardiac device, most of them a cardiac resynchronization therapy (CRT) device. Comparing CRT with non-CRT pts, no differences were found in terms of medical therapy, but better outcomes were observed in CRT group: LVEF improvement was higher (median LVEF improvement of 11% in non-CRT vs 27% in CRT; p < 0.001), and fully recovery from LVD was more frequent (50% of CRT vs 14% non-CRT; p = 0.028). our data strengthen current evidence on natural history of iLBBB, showing significant CV morbidity associated with the presence of iLBBB, and reinforces the need for a serial and proper FU of these carriers. Our data on "real-world" possible LBBB-CMP pts shows high rates of CV events, namely HF-related events, and supports the growing evidence pointing out CRT as this subgroup of pts' cornerstone of treatment. In conclusion, our work sheds additional light on these largely unknown topics and underlines the urgent need for larger and prospective studies addressing the identification of LVD development predictors in iLBBB carriers, as well as the establishment of diagnostic criteria and therapeutic approach for LBBB-CMP.

Association Between the Use of an Adaptive Cardiac Resynchronization Therapy Algorithm and Health Care Use and Cost

To assess the association between use of adaptive pacing on clinical and economic outcomes of CRT recipients in a real-world analysis. The AdaptivCRTTM algorithm was shown in prior subgroup analyses of prospective trials to achieve clinical benefits, but a large prospective trial showed nonsignificant changes in the endpoint of mortality or heart failure hospitalizations. CRT-implanted patients from the Optum Clinformatics® database with ≥90 days of follow-up were included. Remote monitoring data was used to classify patients based on CRT setting - adaptive biventricular and left ventricular pacing (aCRT) vs. standard biventricular pacing (Standard CRT). Inverse probability of treatment weighting was used to adjust for baseline differences between groups. Mortality, 30-day readmissions, healthcare utilization, and payer and patient costs were evaluated post-implantation. This study included 2,412 aCRT and 1,638 Standard CRT patients (mean follow-up: 2.4 ± 1.4 years), with balanced baseline characteristics after adjustment. The aCRT group was associated with lower all-cause mortality (adjusted hazard ratio = 0.88 [95% confidence interval (CI):0.80, 0.96]), fewer all-cause 30-day readmissions (adjusted incidence rate ratio = 0.87 [CI:0.81, 0.94]), and fewer all-cause and HF-related inpatient, outpatient, and emergency department (ED) visits. The aCRT cohort was also associated with lower all-cause outpatient payer-paid amounts and lower all-cause and HF-related inpatient and ED patient-paid amounts. In this retrospective analysis of a large real-world cohort, use of an adaptive CRT algorithm was associated with lower mortality, reduced healthcare resource utilization, and lower payer and patient costs. While cardiac resynchronization therapy (CRT) improves quality of life and clinical outcomes for certain heart failure patients, some patients do not respond to this therapy. Adaptive CRT algorithms (aCRT), such as AdaptivCRTTM, have been developed with the goal of improving effectiveness of CRT, and consequently, clinical and economic outcomes. This research study used a large database of administrative claims data - which contains information on patient demographics, diagnoses, healthcare services received, mortality, and cost data - to compare clinical and economic outcomes between CRT patients with the aCRT algorithm turned on (aCRT group) and CRT patients with the aCRT algorithm turned off (standard CRT group). Statistical methods were used to adjust for baseline differences between the aCRT group and standard CRT groups. Ultimately, the aCRT group was found to have a lower risk of all-cause mortality, fewer all-cause 30-day readmissions, fewer hospital visits (including inpatient, outpatient, and emergency department visits), and lower costs to payers and patients for specific types of costs.

Multicenter Study of Survival Benefit of Cardiac Resynchronization Therapy in Pediatric and Congenital Heart Disease

BackgroundEvidence for the efficacy of cardiac resynchronization therapy (CRT) in pediatric and congenital heart disease (CHD) has been limited to surrogate outcomes. ObjectivesThis study aimed to assess the impact of CRT upon the risk of transplantation or death in a retrospective, high-risk, controlled cohort at 5 quaternary referral centers. MethodsBoth CRT patients and control patients were <21 years of age or had CHD; had systemic ventricular ejection fraction <45%; symptomatic heart failure; and significant electrical dyssynchrony (QRS duration z score >3 or single-site ventricular pacing >40%) at enrollment. Patients with CRT were matched with control patients via 1:1 propensity score matching. CRT patients were enrolled at CRT implantation; control patients were enrolled at the outpatient clinical encounter where inclusion criteria were first met. The primary endpoint was transplantation or death. ResultsIn total, 324 control patients and 167 CRT recipients were identified. Mean follow-up was 4.2 ± 3.7 years. Upon propensity score matching, 139 closely matched pairs were identified (20 baseline indices). Of the 139 matched pairs, 52 (37.0%) control patients and 31 (22.0%) CRT recipients reached the primary endpoint. On both unadjusted and multivariable Cox regression analysis, the risk reduction associated with CRT for the primary endpoint was significant (HR: 0.40; 95% CI: 0.25-0.64; P < 0.001; and HR: 0.44; 95% CI: 0.28-0.71; P = 0.001, respectively). On longitudinal assessment, the CRT group had significantly improved systemic ventricular ejection fraction (P < 0.001) and shorter QRS duration (P = 0.015), sustained to 5 years. ConclusionsIn pediatric and CHD patients with symptomatic systolic heart failure and electrical dyssynchrony, CRT was associated with improved heart transplantation-free survival.

Left bundle branch block cardiomyopathy: an intriguing and defiant entity from diagnosis to treatment

Abstract Introduction and objectives Left bundle branch block cardiomyopathy (LBBB-CM) is an increasingly recognized entity, where electromechanical dyssynchrony seems to play a central role in left ventricular dysfunction (LVD) development. This is a challenging and scarcely studied topic, as causality dilemma between LBBB and LVD is still unsolved. Our aim is to increase current evidence on the subject by analyzing a population of idiopathic LBBB patients (pts) who developed, at some point, LVD not explained by other causes. Methods Retrospective study of LBBB adult pts screened from a large tertiary care hospital electrocardiographic database from 2011 to 2017. After careful evaluation, only possible LBBB-CM pts with serial follow-up (FU) echocardiographic and clinical data were included in the analysis. Results 53 pts were identified as possible LBBB-CMP. At baseline, 44% presented left ventricular ejection fraction (LVEF)&amp;gt;50%, while 56% had LVD. 51% were female and mean age at first-ever LBBB report was 59 years-old. All cohort presented echocardiographic mechanical desynchrony, and additional testing to exclude other causes of LVD (non-invasive ischemia testing in 78%; coronariography in 68%; cardiac magnetic resonance in 38%). Median FU time was 10 years. Worst-LVD was reported as severe in 49% of pts, moderate in 23% and mild in 28%. Median time-to-dysfunction in those with initial LVEF&amp;gt;50% was 8 years. 77% of pts presented heart-failure (HF) symptoms. 40% and 42% presented at least 1 CV event and CV hospitalization, respectively. Most events and/or hospitalizations were due to acute decompensated HF. 2 CV deaths were observed. Cardiac resynchronization therapy (CRT) devices were implanted in 47% of pts. All presented clinical improvement after implantation, and LVEF significantly increased (pre-CRT median LVEF of 24% vs 48% post-CRT; p&amp;lt;0.001). When comparing pts with vs without CRT (Figure 1), better LVEF improvements were achieved in CRT group (median LVEF improvement of 27% in CRT vs 11%; p&amp;lt;0.001). Repeating the latter analysis in pts who only presented at least moderate dysfunction, higher LVEF increase was also reported in CRT group (median LVEF improvement of 27% in CRT pts vs 14%; p=0.002), and significantly more CRT pts recovered LV function (50% CRT vs 14% non-CRT; p=0.028). Notably, no differences were found in rates of medical HF therapy between groups (p=1). Conclusion Our data shows LBBB-CM as a diagnosis of exclusion, where careful evaluation of other LVD etiologies should be performed and discarded. We highlight important morbidity rates in this population, namely HF hospitalizations, as well as the apparently critical role of CRT implantation in these pts. All our CRT pts responded excellently to the therapy. Thus, our study raises awareness to the emerging question of whether this entity can be reversed after LBBB correction with CRT and if early intervention would be desirable.Figure 1

Comparative study of the effects of left ventricular and biventricular pacing on indices of cardiac function and clinical status of heart failure patients: preliminary results of READAPT study

Abstract Nonresponse to cardiac resynchronization therapy (CRT) has been related with right ventricular dysfunction. Preferential left ventricular pacing (pLVP) can overcome iatrogenic right ventricular dysfunction by achieving left ventricle resynchronization and by allowing for intrinsic activation of the right side, with ramifications extending beyond cardiac output and atrial fibrillation occurrence. Moreover, the AdaptivCRT® algorithm also automatically adjusts interventricular (V-V) delay every minute, optimizing it by means of comparing relative activation delay between right and left ventricles (electrically – driven optimization). In the present study we evaluated the effects of a pLVP algorithm on 50 heart failure patients (all Caucasians, 49% male; 66 +/- 8 years old; 46% ischemic cardiomyopathy; 41% diabetics; NYHA II-III) following randomization to standard biventricular pacing and pLVP, on echocardiographic and cardiopulmonary exercise test indices of functional status, as well as a self-reported quality of life questionnaire. Device programming was based on echocardiography-evaluated maximization of stroke volume and subsequent interventricular and atrioventricular delay adjustments delegated to the device. The follow-up consisted of 6 and 12-months visits; after the 1rst month of optimizing maximum CRT response. Results Significant comparative effects of LVP over optimized CRT were noted regarding RV systolic velocity in TDI even from 6-months from baseline (6% increase, p=0.01); while end-systolic diameter of left ventricle was increased by 4% in 6-months in CRT group (p=0.01), while no significant difference was observed in LVP group. At 12 months endsystolic volume was significantly decreased (16%, p=0.01) and left ventricular systolic longitudinal strain was improved in 12 months in LVP group compared to CRT group (p- for interaction =0.001). Additionally, in cardiorespiratory exercise test LVP group showed improved inotropic reserve compared to CRT group according to maximum SBP achieved (20% increase, p&amp;lt;0.01 for interaction); while all other cardiorespiratory indices shoed borderline significant changes at 12 -months. Minnesota score was significantly reduced in LV-P group by 70% at 6-months; whereas no significant change was observed in CRT group (p for interaction &amp;lt;0.01). Conclusions In the preliminary findings of READAPT study, it seems that LV pacing optimized by a standardized echocardiographic protocol in patients with preserved AV conduction, LBBB, can achieve a higher percentage of synchronized LV pacing associated with improved patient quality of life; right ventricular function and endsystolic volume at 6 and 12-months of follow-up, over echo-optimized CRT pacing.

Abstract 16252: A Survival Analysis in Patients With Tricuspid Regurgitation and Cardiac Resynchronization Therapy

Introduction: Cardiac resynchronization therapy (CRT) is a well established treatment in heart failure with reduced ejection fraction. It involves simultaneous pacing of the left and right ventricles to restore ventricular synchrony, leading to increased cardiac output and contractility. The impact of CRT on tricuspid regurgitation (TR) severity has not been evaluated. Studies have shown that up to 22% of CRT recipients have significant TR, and of these patients only 41% will improve to no or mild TR. For a majority of patients who have persistent significant TR despite CRT, long term outcomes are put into question. Hypothesis: Tricuspid regurgitation adversely affects the response and survival of CRT patients. Goals: To analyze the prevalence of TR in a cohort of patients admitted to The Christ Hospital who have undergone CRT. To assess the association between TR after CRT and long-term survivability. Methods: This is a retrospective cohort study conducted at The Christ Hospital in Cincinnati Ohio. 13292 patients diagnosed with tricuspid regurgitation (mild to severe) in total were included. 184 of these patients underwent CRT, and survival probability was measured against the no CRT group. Kaplan meier method was used for analysis. Results: Survival probabilities at 1 year, 2 years, and 3 years for patients with CRT = 0.769, 0.661, and 0.558 respectively. Patients without CRT = 0.911, 0.863, and 0.826 respectively. Hazard ratio = 2.84 (2.33, 3.47) compared to solely tricuspid regurgitation. Conclusions: Patients with TR without CRT had greater survival rates up to three years compared to TR with CRT. The risk of death in the TR with CRT was 2.84 times higher than the no CRT group. It can be further investigated why the no CRT group had a greater survival rate than CRT. Limitations include variable assessments of TR due to the subjective nature of grading TR. Future research could investigate the difference between primary (device-related) and secondary TR in this cohort.

Cardiac Magnetic Resonance, Electromechanical Activation, Kidney Function, and Natriuretic Peptides in Cardiac Resynchronization Therapy Upgrades.

As the mechanism for worse prognosis after cardiac resynchronization therapy (CRT) upgrades in heart failure patients with RVP dependence (RVP-HF) has clinical implications for patient selection and CRT implementation approaches, this study's objective was to evaluate prognostic implications of cardiac magnetic resonance (CMR) findings and clinical factors in 102 HF patients (23.5% female, median age 66.5 years old, median follow-up 4.8 years) with and without RVP dependence undergoing upgrade and de novo CRT implants. Compared with other CRT groups, RVP-HF patients had decreased survival (p = 0.02), more anterior late-activated LV pacing sites (p = 0.002) by CMR, more atrial fibrillation (p = 0.0006), and higher creatinine (0.002). CMR activation timing at the LV pacing site predicted post-CRT LV functional improvement (p < 0.05), and mechanical activation onset < 34 ms by CMR at the LVP site was associated with decreased post-CRT survival in a model with higher pre-CRT creatinine and B-type natriuretic peptide (AUC 0.89; p < 0.0001); however, only the higher pre-CRT creatinine partially mediated (37%) the decreased survival in RVP-HF patients. In conclusion, RVP-HF had a distinct CMR phenotype, which has important implications for the selection of LV pacing sites in CRT upgrades, and only chronic kidney disease mediated the decreased survival after CRT in RVP-HF.

Seismocardiography as a tool for assessment of bi-ventricular pacing

Objective. Conduction-induced heart failure in patients with left bundle branch block (LBBB) can benefit from cardiac resynchronization therapy (CRT). However, some patients are non-responders to the therapy with one contributing factor being poor optimization of the atrioventricular (AV) pacing delay. In this study, we have investigated the pacing-induced changes in the seismocardiogram (SCG). Approach. 14 patients with heart failure, LBBB, and CRT were included. SCG was recorded with pacing turned on and off. Based on a mean SCG heartbeat from each patient, fiducial points were annotated, and cardiac timing intervals (CTI) and amplitudes were derived. These were compared between the CRT group and a group of healthy normal subjects (n = 14). Echocardiography was also used to derive CTI. Intervals derived from the SCG and echocardiogram were correlated. Main results. The isovolumetric contraction time (IVCT) derived from SCG was significantly shorter in the CRT group when the pacemaker was turned on (63.2–52.6 ms, p = 0.027). The first peak-to-peak amplitude in the systolic complex was significantly larger with the pacemaker turned on (p = 0.002), as well as the ∣max-min∣ amplitude in the systolic complex (p = 0.003). Isovolumetric relaxation time and left ventricular ejection time (LVET) were not significantly different between pacemaker settings. Compared to normal subjects, IVCT was significantly prolonged with the pacemaker turned off. All amplitudes were significantly larger in the healthy subject group. IVCT and LVET derived from SCG were significantly correlated to the echocardiogram. Significance. IVCT shortened and SCG amplitudes increased in response to CRT, indicating a more efficient ventricular contraction. This demonstrates the possibility to detect cardio-mechanic changes in response to treatment with the SCG. However, for the patients the systolic part of the SCG was abnormal and difficult to characterize, raising concerns about the correct interpretation of the SCG.

Predictive Ability of Cardiopulmonary Exercise Test Parameters in Heart Failure Patients with Cardiac Resynchronization Therapy.

ResumoFundamento Há evidências sugerindo que um corte do pico de consumo de oxigênio (pVO2) de 10ml/kg/min fornece uma estratificação de risco mais precisa em pacientes com Terapia de Ressincronização Cardíaca (TRC).Objetivo Comparar o poder prognóstico de vários parâmetros do teste cardiopulmonar de exercício (TCPE) nesta população e avaliar a capacidade discriminativa dos valores de corte de pVO2 recomendados pelas diretrizes.Métodos Avaliação prospectiva de uma série consecutiva de pacientes com insuficiência cardíaca (IC) com fração de ejeção do ventrículo esquerdo ≤40%. O desfecho primário foi um composto de morte cardíaca e transplante cardíaco urgente (TC) nos primeiros 24 meses de acompanhamento, e foi analisado por vários parâmetros do TCPE para a maior área sob a curva (AUC) no grupo TRC. Uma análise de sobrevida foi realizada para avaliar a estratificação de risco fornecida por vários pontos de corte diferentes. Valores de p < 0,05 foram considerados significativos.Resultados Um total de 450 pacientes com IC, dos quais 114 possuíam aparelho de TRC. Esses pacientes apresentaram um perfil de risco basal mais alto, mas não houve diferença em relação ao desfecho primário (13,2% vs 11,6%, p = 0,660). A pressão expiratória de dióxido de carbono no limiar anaeróbico (PETCO2AT) teve o maior valor de AUC, que foi significativamente maior do que o de pVO2 no grupo TRC (0,951 vs 0,778, p = 0,046). O valor de corte de pVO2 atualmente recomendado forneceu uma estratificação de risco precisa nesse cenário (p <0,001), e o valor de corte sugerido de 10 ml/min/kg não melhorou a discriminação de risco em pacientes com dispositivos (p = 0,772).Conclusão A PETCO2AT pode superar o poder prognóstico do pVO2 para eventos adversos em pacientes com TRC. O ponto de corte de pVO2 recomendado pelas diretrizes atuais pode estratificar precisamente o risco dessa população.

Sex-related differences in the prognosis of patients with cardiac sarcoidosis treated with cardiac resynchronization therapy.

Past studies have shown the sex-related difference in the efficacy of cardiac resynchronization therapy (CRT). However, the data for cardiac sarcoidosis (CS) are limited. The purpose of this study was to assess the sex-related prognostic differences in CS patients with CRT. This multicenter CS survey included 430 patients (295 females) who met the diagnostic criteria for CS. Patients were divided into those treated with primary CRT or upgraded CRT from the pacemaker (CRT group; n = 73) and others (control group; n = 357). Sex differences in the incidence of all-cause death, heart failure (HF) death including heart transplantation, ventricular arrhythmia events (VAEs) (sudden death, appropriate device therapy), cardiac adverse events (CAEs) (HF death, VAEs), changes in serum brain natriuretic peptide (BNP) levels, and left ventricular ejection fraction (LVEF) over the follow-up period were analyzed. During median follow-up of 5.2 years, males, but not females, in the CRT group had significantly worse all-cause mortality than patients in the control group (P <.001). In the CRT group, there was no significant sex-related difference in the incidence of HF death; however, females had significantly better VAE- and CAE-free survival than males (P = .033 and P = .008, respectively). Multivariate analysis of the CRT group showed that female sex (hazard ratio 0.37; 95% confidence interval 0.15-0.89; P = .02 and P = .6) independently predicted freedom from CAEs. During follow-up, BNP levels were significantly improved in all groups. LVEF was maintained in females with CRT. In CS patients with CRT, HF death-free survival was similar between sexes. However, females exhibited better VAE- and CAE-free survival than males.

Safety and Effectiveness of Transvenous Lead Extraction in Patients with Infected Cardiac Resynchronization Therapy Devices; Is It More Risky than Extraction of Other Systems?

Background: Transvenous lead extraction (TLE) in patients with implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) devices is considered as more risky. The aim of this study was to assess the safety and effectiveness of TLE in patients with infected CRT systems. Methods: Data of 3468 patients undergoing TLE in a single high-volume center in years 2006–2021 were analyzed. The clinical and procedural parameters as well as the efficacy and safety of TLE were compared between patients with infected CRT and pacemakers (PM) and ICD systems. Results: Infectious indications for TLE occurred in 1138 patients, including 150 infected CRT (112 CRT-D and 38 CRT-P). The general health condition of CRT patients was worse with higher Charlson’s comorbidity index. The number of extracted leads was higher in the CRT group, but implant duration was significantly longer in the PM than in the ICD and CRT groups (98.93 vs. 55.26 vs. 55.43 months p < 0.01). The procedure was longer in duration, more difficult, and more complex in patients with pacemakers than in those in the CRT group. The occurrence of major complications and clinical and procedural success as well as procedure-related death did not show any relationship to the type of CIED device. Mortality at more than one-year follow-up after TLE was significantly higher among patients with CRT devices (22.7% vs. 8.7%) than among those in the PM group. Conclusion: Despite the greater burden of lead and comorbidities, the complexity and efficiency of removing infected CRT systems is no more dangerous than removing other infected systems. The duration of the implant seems to play a dominant role.

Cardiac resynchronization therapy in non-ischemic cardiomyopathy: a comparative non-randomized study of His Bundle pacing versus biventricular pacing.

Cardiac resynchronization therapy (CRT) via permanent His bundle pacing (pHBP) has gained acceptance globally, but robust studies comparing pHBP-CRT with classic CRT are lacking. In this study, we aimed to compare the improvement in left ventricular ejection fraction (LVEF) after pHBP-CRT versus classic CRT. This was a single-center study comparing a prospective series of pHBP-CRT with a historical series of CRT via classic biventricular pacing (BVP). Patients with non-ischemic cardiomyopathy, baseline LVEF < 35%, left bundle branch block (LBBB), and CRT indications were selected. Fifty-one patients underwent classic CRT and 52 patients underwent pHBP-CRT. In the classic CRT group, the median (interquartile range) basal LVEF was 30% (IQR, 29-35%) before implantation and 40% (35-48%) at follow-up. In the pHBP-CRT group, the median basal LVEF was 30% (28-34%) before implantation and 55% (45-60%) at follow-up, with significant differences between both modalities at follow-up (p = 0.001). The median long term His recruitment threshold with LBBB correction was 1.25 (1-2.5) V at 0.4ms in cases of pHBP-CRT, compared to a left ventricular coronary sinus threshold of 1.25 (1-1.75) V in cases of classic CRT (p = 0.48). After CRT, the median paced QRS was 135 (120-145) ms for pHBP-CRT versus 140 (130-150) ms for BVP-CRT (p = 0.586). The improvement in LVEF was superior with pHBP-CRT than with classic CRT. The thresholds at follow-up were similar in both groups.

Cardiac implantable electronic devices procedures and their recipients characteristic during COVID-19 pandemic: 3.8 million population analysis.

BackgroundCoronavirus disease 2019 (COVID-19) pandemic disorganised healthcare systems and has caused a reduction in the number of hospitalizations and procedures. Cardiac implantable electronic device (CIED) procedure rates and clinical characteristics of their recipients were compared in corresponding weeks of 2019 and 2020 were analyzed.MethodsThe database of the National Health Fund (NHF) in Poland was retrospectively analyzed. 3206 patients who underwent CIED implantation in the Silesia — a region in Southern Poland comprising an adult population of 3.8 million between 12th and 31st week of 2020. Patients were classified into groups: the recipient of an implantable cardioverter-defibrillator or cardiac resynchronization therapy group (ICD/CRT) or pacemaker group (PM).ResultsDuring the pandemic a reduction of 39.38% of implantations was observed compared to the same period in 2019 (1210 vs. 1996 patients) and had impacted both groups. Two phases lasting 10 weeks each could be distinguished: total lockdown (maximal reduction) and the recovery phase with growing numbers of procedures. Patient baseline characteristics (sex, age, comorbidities) who were implanted during the COVID-19 pandemic did not differ from the 2019 period. The rate of peri-procedural mortality was also similar.ConclusionsDuring COVID-19 pandemic period a reduction in CIED implantations of all types was observed. Despite the decreased number of performed CIED implants, no differences in baseline patient characteristics were observed.

The Impact of Charlson Comorbidity Index on De Novo Cardiac Implantable Electronic Device Procedural Outcomes in the United States

ObjectiveTo investigate the utility of Charlson comorbidity index (CCI) as a measure of comorbidity burden to predict procedural outcomes after de novo cardiac implantable electronic device (CIED) implantation. MethodsAll de novo CIED implantations in the United States National Inpatient Sample between 2015 and 2018 were retrospectively analyzed, stratified by CCI score (0=no comorbidity burden, 1=mild, 2=moderate, ≥3=severe). Multivariable logistic regression models were performed to examine the association between unit CCI score (scale) and in-hospital outcomes (major adverse cerebrovascular and cardiovascular events [MACCE]: composite of all-cause mortality, acute ischemic stroke, thoracic and cardiac complications, and device-related complications; and MACCE individual components). ResultsOf 474,475 CIED procedures, the distribution of CCI score was as follows: CCI=0 (17.7%), CCI=1 (21.8%), CCI=2 (18.7%), and CCI=3+ (41.8%). Charlson comorbidity index score was associated with increased odds ratios of MACCE (1.10; 95% CI, 1.09 to 1.11), all-cause mortality (1.23; 95% CI, 1.21 to 1.25), and acute stroke (1.45; 95% CI, 1.44 to 1.46). This finding was consistent across all CIED groups except the cardiac resynchronization therapy groups in which CCI was not associated with increased risk of mortality. A higher CCI score was not associated with increased odds of procedural (thoracic and cardiac) and device-related complications. ConclusionIn a nationwide cohort of CIED procedures, higher comorbidity burden as measured by CCI score was associated with an increased risk of in-hospital mortality and acute ischemic stroke, but not procedure-related (thoracic and cardiac) or device-related complications. Objective assessment of comorbidity burden is important to risk-stratify patients undergoing CIED implantation for better prognostication of their in-hospital survival.

Abstract 13557: Impact of Cardiac Resynchronization Therapy on Clinical Outcomes in Transthyretin Amyloid Cardiomyopathy

Introduction: Due to conduction disease and dyssynchrony in transthyretin amyloid cardiomyopathy (ATTR-CM), cardiac resynchronization therapy (CRT) may be beneficial. We aimed to determine the impact of CRT on clinical outcomes in ATTR-CM. Methods: We studied 116 consecutive ATTR-CM patients, 23 of whom underwent CRT (70% CRT + defibrillator, median 10 months (IQR 4-20) from ATTR-CM diagnosis). Outcome was a composite of 1 st cardiovascular hospitalization or all-cause mortality. CRT was treated as a time dependent co-variate and entered into multivariate Cox proportional hazards model. Results: Both groups were similar at diagnosis except for a higher proportion with atrial fibrillation (AF) and lower ejection fraction among those who underwent CRT ( Table 1) . CRT indication in 80% was progressive LV dysfunction with wide QRS [mean 152 ± 36 msec] and the remaining at time of AV node ablation for AF. Half of CRT group were ≥ NYHA class III at device implantation. Older age, higher National Amyloidosis Cohort (NAC) ATTR stage, and not taking tafamidis were significantly associated with the outcome. On multivariate analysis, CRT was associated with a HR of 0.6 (95% CI: 0.32 - 1.16) for all-cause mortality or cardiovascular hospitalization after adjusting for age at diagnosis, NAC ATTR stage, and tafamidis use ( Figure 1). Conclusion: CRT implantation maybe associated with improved outcomes in ATTR-CM. Larger prospective randomized, sham-controlled trials are warranted to confirm these findings.

Assessing long-term survival and hospitalization following transvenous lead extraction in patients with cardiac resynchronization therapy devices: A propensity score-matched analysis.

BackgroundLonger-term outcomes of patients post transvenous lead extraction (TLE) are poorly understood in patients with cardiac resynchronization therapy (CRT) devices.ObjectivesA propensity score (PS)–matched analysis evaluating outcomes post TLE in CRT and non-CRT populations was performed.MethodsData from consecutive patients undergoing TLE between 2000 and 2019 were prospectively collected. Patients surviving to discharge and reimplanted with the same device were included. The cohort was split depending on presence of CRT device. Associations with all-cause mortality and hospitalization were assessed by Kaplan-Meier estimates. An exploratory endpoint was evaluated whether early (<7 days) or late (>7 days) reimplantation was associated with poorer outcomes.ResultsOf 1005 patients included, 285 (25%) had a CRT device. Median follow-up was 57.00 [27.00–93.00] months, age at explant was 67.7 ± 12.1 years, 83.3% were male, and 54.4% had an infective indication for TLE. PS was calculated using 43 baseline characteristics. After matching, 192 CRT patients were compared with 192 non-CRT patients. In the matched cohort, no significant difference with respect to mortality (hazard ratio [HR] = 1.01, 95% confidence interval [CI] [0.74–1.39], P = .093) or hospitalization risk (HR = 1.2, 95% CI [0.87–1.66], P = .265) was observed. In the matched CRT group, late reimplantation was associated with increased mortality (HR = 1.64, [1.04–2.57], P = .032) and hospitalization risk (HR = 1.57, 95% CI [1.00–2.46], P = .049].ConclusionOutcomes of CRT patients post TLE are similarly as poor as those of non-CRT patients in matched populations. Reimplantation within 7 days was associated with better outcomes in a CRT population but was not observed in a non-CRT population, suggesting prolonged periods without biventricular pacing should be avoided.

Epicardial Adipose Tissue Measured From Computed Tomography Predicts Cardiac Resynchronization Therapy Response in Patients With Non-ischemic Systolic Heart Failure.

Background: Epicardial adipose tissue (EAT) has been linked with the pathogenesis of heart failure (HF). Limited data have been reported about the clinical value of EAT for cardiac resynchronization therapy (CRT) in non-ischemic systolic HF. We aimed to explore the values of EAT measured from CT to predict the response to CRT in patients with non-ischemic systolic HF.Methods: Forty-one patients with CRT were consecutively recruited for our study. All patients received both gated resting Single Photon Emission CT (SPECT) myocardial perfusion imaging (MPI) and dual-source multi-detector row CT scans. EAT thickness was assessed on both the parasternal short and horizontal long-axis views. The area of EAT was calculated at the left main coronary artery level. Left ventricular systolic mechanical dyssynchrony (LVMD) was measured by phase standard deviation (PSD) and phase histogram bandwidth (PBW). The definition of CRT response was an improvement of 5% in left ventricular ejection fraction (LVEF) at 6 months after CRT implantation.Results: After 6 months of follow-up, 58.5% (24 of 41) of patients responded to CRT. A greater total perfusion deficit (TPD) was observed in the left ventricle, and a narrower QRS complex was observed in the nonresponse group than in the response group (p < 0.05). Meanwhile, the systolic PSD and systolic PBW were statistically greater in the CRT group with no response than in the response group (p < 0.05). Meanwhile, the baseline QRS duration, TPD, systolic PSD, systolic PBW, EAT thicknesses of the left ventricular (LV) apex, right atrioventricular (AV) groove, and left AV groove were all significantly related to the CRT response in the univariate logistic regression analysis. Furthermore, the QRS duration and EAT thicknesses of the right AV groove and left AV groove were independent predictors of CRT response in the multivariate logistic regression analysis.Conclusions: The EAT thickness of the left AV groove in patients with non-ischemic systolic HF is associated with the TPD of LV and LV systolic dyssynchrony. The EAT thickness of the AV groove has a good predictive value for the CRT response in patients with non-ischemic systolic HF.