A self-powered intracardiac pacemaker in swine model.

Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 μA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.

Effect of short-term cardiac function changes after cardiac resynchronization therapy on long-term prognosis in heart failure patients with and without diabetes.

Background:The relationship between short-term cardiac function changes and long-term outcomes in heart failure (HF) patients undergoing cardiac resynchronization therapy (CRT) remains uncertain, especially when stratified by diabetes status.Objectives:This study aims to assess the association between short-term cardiac function changes and outcomes such as all-cause mortality and HF hospitalization in patients undergoing CRT, stratified by diabetes status.Design:This is a cohort longitudinal retrospective study.Methods:A total of 666 HF patients, treated with CRT between March 2007 and March 2019, were included in this study. Among them, 166 patients (24.9%) were diagnosed with diabetes. Cardiac function was assessed at baseline and again at 6 months, incorporating evaluations of left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), left atrial diameter (LAD), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and QRS duration. The QRS duration represents the time required for a stimulus to spread through the ventricles (ventricular depolarization). The primary endpoints of the study were all-cause mortality and HF-related hospitalization.Results:During a median follow-up of 2.51 years, 172 (25.8%) patients died and 197 (29.6%) were hospitalized for HF. Changes in LVEF, LVEDD, and LAD within 6 months had similar effects on adverse outcomes in both diabetic and nondiabetic patients. However, the presence of diabetes significantly modified the association between changes in NT-proBNP and QRS duration and adverse outcomes. Short-term changes in NT-proBNP and QRS duration were positively associated with all-cause mortality and HF hospitalization in patients without diabetes. However, the relationship between short-term changes in NT-proBNP and QRS duration and adverse outcomes was non-linear in diabetic patients.Conclusion:Improvement of cardiac function after CRT implantation can reduce long-term risk of all-cause mortality and HF hospitalization in HF patients. However, the presence of diabetes may affect the association between short-term changes in NT-proBNP and QRS duration and adverse outcomes.

Dyssynchronous heart failure models in canines: New insights into electrocardiographic, echocardiographic and histological features.

BACKGROUND:We investigated the similarities and differences between two experimental approaches using tachy-pacing technology to induce desynchronized heart failure in canines.METHODS:A total of eight dogs were included in the experiment, four were tachy-paced in right ventricle apex (RVAP) and 4 were paced in right atrium after the ablation of left bundle branch to achieve left bundle branch block (RAP+LBBB). Three weeks of follow-up were conducted to observe the changes in cardiac function and myocardial staining was performed at the end of the experiment.RESULTS:Both experimental approaches successfully established heart failure with reduced ejection fraction models, with similar trends in declining cardiac function. The RAP+LBBB group exhibited a prolonged overall ventricular activation time, delayed left ventricular activation, and lesser impact on the right ventricle. The RVAP approach led to a reduction in overall right ventricular compliance and right ventricular enlargement. The RAP+LBBB group exhibited significant reductions in left heart compliance (LVGLS, %: RAP+LBBB -12.60 ± 0.12 to -5.93 ± 1.25; RVAP -13.28 ± 0.62 to -8.05 ± 0.63, p = 0.023; LASct, %: RAP+LBBB -15.75 ± 6.85 to -1.50 ± 1.00; RVAP -15.75 ± 2.87 to -10.05 ± 6.16, p = 0.035). Histological examination revealed more pronounced fibrosis in the left ventricular wall and left atrium in the RAP+LBBB group while the RVAP group showed more prominent fibrosis in the right ventricular myocardium.CONCLUSION:Both approaches establish HFrEF models with comparable trends. The RVAP group shows impaired right ventricular function, while the RAP+LBBB group exhibits more severe decreased compliance and fibrosis in left ventricle.

Metabolomics Profiling Predicts Ventricular Arrhythmia in Patients with an Implantable Cardioverter Defibrillator.

Implantable cardioverter defibrillators (ICDs) reduce sudden cardiac death (SCD) when patients experience life-threatening ventricular arrhythmias (LTVA). However, current strategies determining ICD patient selection and risk stratification are inefficient. We used metabolomics to assess whether dysregulated metabolites are associated with LTVA and identify potential biomarkers. Baseline plasma samples were collected from 72 patients receiving ICDs. Over a median follow-up of 524.0 days (range 239.0-705.5), LTVA occurred in 23 (31.9%) patients (22 effective ICD treatments and 1 SCD). After confounding risk factors adjustment for age, smoking, secondary prevention, and creatine kinase MB, 23 metabolites were significantly associated with LTVA. Pathway analysis revealed LTVA associations with disrupted metabolism of glycine, serine, threonine, and branched chain amino acids. Pathway enrichment analysis identified a panel of 6 metabolites that potentially predicted LTVA, with an area under the receiver operating characteristic curve of 0.8. Future studies are necessary on biological mechanisms and potential clinical use.

Joint association of sedentary behavior and vitamin D status with mortality among cancer survivors.

BACKGROUND:Sedentary behavior and vitamin D deficiency are independent risk factors for mortality in cancer survivors, but their joint association with mortality has not been investigated.METHODS:We analyzed data from 2914 cancer survivors who participated in the National Health and Nutrition Examination Survey (2007-2018) and followed up with them until December 31, 2019. Sedentary behavior was assessed by self-reported daily hours of sitting, and vitamin D status was measured by serum total 25-hydroxyvitamin D (25(OH)D) levels.RESULTS:Among 2914 cancer survivors, vitamin D deficiency was more prevalent in those with prolonged daily sitting time. During up to 13.2 years (median, 5.6 years) of follow-up, there were 676 deaths (cancer, 226; cardiovascular disease, 142; other causes, 308). The prolonged sitting time was associated with a higher risk of all-cause and noncancer mortality, and vitamin D deficiency was associated with a higher risk of all-cause and cancer mortality. Furthermore, cancer survivors with both prolonged sitting time (≥ 6 h/day) and vitamin D deficiency had a significantly higher risk of all-cause (HR, 2.05; 95% CI: 1.54-2.72), cancer (HR, 2.33; 95% CI, 1.47-3.70), and noncancer mortality (HR, 1.91; 95% CI, 1.33-2.74) than those with neither risk factor after adjustment for potential confounders.CONCLUSIONS:In a nationally representative sample of U.S. cancer survivors, the joint presence of sedentary behavior and vitamin D deficiency was significantly associated with an increased risk of all-cause and cancer-specific mortality.

Sex differences in the nonlinear association of triglyceride glucose index with all-cause and cardiovascular mortality in the general population.

BACKGROUND:The evidence on the association between the triglyceride glucose (TyG) index and the risk of death in the general population remains controversial. This study aims to investigate the relationship between the TyG index and all-cause and cardiovascular mortality in the general population, with a focus on sex differences.METHODS:This prospective cohort study analyzed data from the National Health and Nutrition Examination Survey (1999-2002), comprising 7,851 US adults. The study employed multivariate Cox proportional hazards regression and two-segment Cox hazard regression models to evaluate the sex-specific differences in the relationship between the TyG index and all-cause and cardiovascular mortality.RESULTS:After 11,623 person-years of follow-up, there were 539 deaths, with 10.56% due to all-cause mortality and 2.87% due to cardiovascular mortality. After adjusting for multiple variables, our study found a U-shaped association of the TyG index with all-cause and cardiovascular mortality, with inflection points at 9.36 and 9.52. A significant sex difference was observed in the association between the TyG index and mortality. Below the inflection point, the relationship between the TyG index and mortality was consistent in males and females. However, above the inflection point, only males exhibited a positive association between the TyG index and all-cause mortality (adjusted hazard risk [HR], 1.62, 95% confidence interval [CI], 1.24-2.12) and cardiovascular mortality (adjusted HR, 2.28, 95% CI, 1.32-3.92).CONCLUSIONS:Our study showed a U-shaped association between the TyG index and all-cause and cardiovascular mortality in the general population. Furthermore, sex differences were observed in the association between the TyG index and mortality once it exceeded a certain threshold.

The impact of chronotropic incompetence on atrioventricular conduction times in heart failure patients.

BACKGROUND:Intrinsic atrioventricular (AV) conduction is used to optimize AV intervals with cardiac resynchronization therapy (CRT) in most device algorithms. Atrial pacing and heart rate affect conduction times, but little is known regarding differeces among chronotropic incompetent(CI) and competent(CC) patients to guide programming.METHODS:RAVE was a multicenter prospective trial of CRT patients. Heart rate was increased with incremental atrial pacing and with submaximal exercise. According to the maximal heart rate achieved during exercise, patients were classified as either CI or CC. For CI patients, an additional symptom-limited exercise with rate-adaptive pacing activated was performed. Intracardiac intervals were measured from the implantable lead electrograms in multiple postures.RESULTS:There were 12 subjects with CI and 24 with CC. With atrial pacing, AV interval immediately increased and gradually increased with incremental atrial pacing in all patients. However, the changes in the atrial to right ventricular (ARV) and atrial to left ventricular (ALV) intervals with increasing atrial pacing rates were about threefold greater in CI patients compared to CC patients (24.3 ± 28.9 vs. 7.2 ± 5.5 ms/10 bpm for ARV and 22.7 ± 25.6 vs. 7.1 ± 5.7 ms/10 bpm for ALV in the standing position, p < 0.05). In CI pacing with rate-adaptive pacing during exercise, AV interval changes with paced heart rate were variable.CONCLUSIONS:The AV response to overdrive atrial pacing at rest may provide a simple means of identifying chronotropic competence in CRT patients. For patients with CI, who often require rate-adaptive atrial pacing, rate-adaptive AV algorithms should be adjusted individually.

Letter regarding the article 'Clinical implications of left atrial changes after optimization of medical therapy in patients with heart failure'.

Clinical outcome of lesion size index-guided high-power radiofrequency catheter ablation for pulmonary vein isolation in patients with atrial fibrillation: 2-year follow-up.

INTRODUCTION:The long-term efficacy of high-power (50 W) ablation guided by lesion size index (LSI-guided HP) for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) remains undetermined. Our study sought to assess the clinical efficacy of LSI-guided HP ablation for PVI in patients with AF and explore the potential predictors associated with clinical outcomes.METHODS:We consecutively included 186 patients with AF who underwent LSI-guided HP (50 W) ablation at Fuwai Hospital from June 2019 to October 2021. The target LSI values of 4.5-5.5 and 4.0-4.5 at the anterior and posterior walls, respectively, were used in our study. The baseline clinical characteristics, procedural and ablation data, and clinical outcomes were evaluated. The independent potential predictors associated with AF recurrence were further evaluated.RESULTS:The incidence rate of first-pass PVI was 83.9% (156/186). A total of 11 883 lesions were analyzed, and compared with posterior walls of pulmonary veins, anterior walls had significantly lower mean contact force (8.2 ± 3.0 vs. 8.3 ± 2.3 g, p = .015), longer mean radiofrequency duration (16.9 ± 7.2 vs. 12.9 ± 4.5 s, p < .001) and higher mean LSI (4.8 ± 0.2 vs. 4.4 ± 0.2, p < .001). The overall incidence of periprocedural complications was 3.7%, and steam pops without pericardial effusion occurred in three patients (1.6%). During a mean follow-up of 24.0 ± 8.4 months, the overall AF recurrence-free survival was 87.1% after a single procedure. Patients with paroxysmal AF had a higher incidence of freedom from AF recurrence than those with persistent AF (91.2% vs. 80.8%, log-rank p = .034). Higher LSI (HR 0.50, p < .001) and paroxysmal AF (HR 0.39, p = .029) were significantly associated with decreased AF recurrence. By receiver operating characteristic analysis, the LSI of 4.7 and 4.3 for the anterior and posterior walls of the PVs had the highest predictive value for AF recurrence, respectively.CONCLUSION:LSI-guided HP (50 W) ablation for PVI was an efficient and safe strategy and led to favorable single-procedure 2-year AF recurrence-free survival in patients with AF. Higher LSI and paroxysmal AF were independent predictors of decreased 2-year AF recurrence. The LSI of 4.7 for the anterior wall and 4.3 for the posterior wall of the PVs were the best cutoff values for predicting AF recurrence after LSI-guided HP ablation.

Effectiveness of adding a defibrillator with cardiac resynchronization therapy in heart failure according to the modified Model for End-stage Liver Disease-Albumin score.

Current guidelines lack clear recommendations between the implantation of cardiac resynchronization therapy (CRT) with defibrillator (CRT-D) and CRT with pacemaker (CRT-P). We hypothesized that modified model for end-stage liver disease score including albumin (MELD-Albumin score), could be used to select patients who may not benefit from CRT-D. We consecutively included patients with CRT-P or CRT-D implantation between 2010 and 2022. The primary endpoint was the composite of all-cause mortality or worsening heart failure. We performed multivariable-adjusted Cox proportional hazard regression. We assessed the interaction between the MELD-Albumin score and the effect of adding a defibrillator with CRT.A total of 752 patients were included in this study, with 291 implanted CRT-P. During a median follow-up of 880 days, 205 patients reached the primary endpoint. MELD-Albumin score was significantly associated with the primary endpoint in the CRT-D group [HR 1.16 (1.09-1.24); P < 0.001] but not in the CRT-P group [HR 1.03 (0.95-1.12); P = 0.49]. There was a significant interaction between the MELD-Albumin score and the effect of CRTD (P = 0.013). The optimal cut-off value of the MELD-Albumin score was 12. For patients with MELD-Albumin ≥ 12, CRT-D was associated with a higher occurrence of the primary endpoint [HR 1.99 (1.10-3.58); P = 0.02], whereas not in patients with MELD-Albumin < 12 [HR 1.19 (0.83-1.70); P = 0.35). Our findings suggest that CRT-D is associated with an excess risk of composite clinical endpoints in HF patients with higher MELD-Albumin score.

A self-powered intracardiac pacemaker in swine model.

Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 μA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.

Effect of short-term cardiac function changes after cardiac resynchronization therapy on long-term prognosis in heart failure patients with and without diabetes.

Background:The relationship between short-term cardiac function changes and long-term outcomes in heart failure (HF) patients undergoing cardiac resynchronization therapy (CRT) remains uncertain, especially when stratified by diabetes status.Objectives:This study aims to assess the association between short-term cardiac function changes and outcomes such as all-cause mortality and HF hospitalization in patients undergoing CRT, stratified by diabetes status.Design:This is a cohort longitudinal retrospective study.Methods:A total of 666 HF patients, treated with CRT between March 2007 and March 2019, were included in this study. Among them, 166 patients (24.9%) were diagnosed with diabetes. Cardiac function was assessed at baseline and again at 6 months, incorporating evaluations of left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), left atrial diameter (LAD), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and QRS duration. The QRS duration represents the time required for a stimulus to spread through the ventricles (ventricular depolarization). The primary endpoints of the study were all-cause mortality and HF-related hospitalization.Results:During a median follow-up of 2.51 years, 172 (25.8%) patients died and 197 (29.6%) were hospitalized for HF. Changes in LVEF, LVEDD, and LAD within 6 months had similar effects on adverse outcomes in both diabetic and nondiabetic patients. However, the presence of diabetes significantly modified the association between changes in NT-proBNP and QRS duration and adverse outcomes. Short-term changes in NT-proBNP and QRS duration were positively associated with all-cause mortality and HF hospitalization in patients without diabetes. However, the relationship between short-term changes in NT-proBNP and QRS duration and adverse outcomes was non-linear in diabetic patients.Conclusion:Improvement of cardiac function after CRT implantation can reduce long-term risk of all-cause mortality and HF hospitalization in HF patients. However, the presence of diabetes may affect the association between short-term changes in NT-proBNP and QRS duration and adverse outcomes.

Dyssynchronous heart failure models in canines: New insights into electrocardiographic, echocardiographic and histological features.

BACKGROUND:We investigated the similarities and differences between two experimental approaches using tachy-pacing technology to induce desynchronized heart failure in canines.METHODS:A total of eight dogs were included in the experiment, four were tachy-paced in right ventricle apex (RVAP) and 4 were paced in right atrium after the ablation of left bundle branch to achieve left bundle branch block (RAP+LBBB). Three weeks of follow-up were conducted to observe the changes in cardiac function and myocardial staining was performed at the end of the experiment.RESULTS:Both experimental approaches successfully established heart failure with reduced ejection fraction models, with similar trends in declining cardiac function. The RAP+LBBB group exhibited a prolonged overall ventricular activation time, delayed left ventricular activation, and lesser impact on the right ventricle. The RVAP approach led to a reduction in overall right ventricular compliance and right ventricular enlargement. The RAP+LBBB group exhibited significant reductions in left heart compliance (LVGLS, %: RAP+LBBB -12.60 ± 0.12 to -5.93 ± 1.25; RVAP -13.28 ± 0.62 to -8.05 ± 0.63, p = 0.023; LASct, %: RAP+LBBB -15.75 ± 6.85 to -1.50 ± 1.00; RVAP -15.75 ± 2.87 to -10.05 ± 6.16, p = 0.035). Histological examination revealed more pronounced fibrosis in the left ventricular wall and left atrium in the RAP+LBBB group while the RVAP group showed more prominent fibrosis in the right ventricular myocardium.CONCLUSION:Both approaches establish HFrEF models with comparable trends. The RVAP group shows impaired right ventricular function, while the RAP+LBBB group exhibits more severe decreased compliance and fibrosis in left ventricle.

Metabolomics Profiling Predicts Ventricular Arrhythmia in Patients with an Implantable Cardioverter Defibrillator.

Implantable cardioverter defibrillators (ICDs) reduce sudden cardiac death (SCD) when patients experience life-threatening ventricular arrhythmias (LTVA). However, current strategies determining ICD patient selection and risk stratification are inefficient. We used metabolomics to assess whether dysregulated metabolites are associated with LTVA and identify potential biomarkers. Baseline plasma samples were collected from 72 patients receiving ICDs. Over a median follow-up of 524.0 days (range 239.0-705.5), LTVA occurred in 23 (31.9%) patients (22 effective ICD treatments and 1 SCD). After confounding risk factors adjustment for age, smoking, secondary prevention, and creatine kinase MB, 23 metabolites were significantly associated with LTVA. Pathway analysis revealed LTVA associations with disrupted metabolism of glycine, serine, threonine, and branched chain amino acids. Pathway enrichment analysis identified a panel of 6 metabolites that potentially predicted LTVA, with an area under the receiver operating characteristic curve of 0.8. Future studies are necessary on biological mechanisms and potential clinical use.

Joint association of sedentary behavior and vitamin D status with mortality among cancer survivors.

BACKGROUND:Sedentary behavior and vitamin D deficiency are independent risk factors for mortality in cancer survivors, but their joint association with mortality has not been investigated.METHODS:We analyzed data from 2914 cancer survivors who participated in the National Health and Nutrition Examination Survey (2007-2018) and followed up with them until December 31, 2019. Sedentary behavior was assessed by self-reported daily hours of sitting, and vitamin D status was measured by serum total 25-hydroxyvitamin D (25(OH)D) levels.RESULTS:Among 2914 cancer survivors, vitamin D deficiency was more prevalent in those with prolonged daily sitting time. During up to 13.2 years (median, 5.6 years) of follow-up, there were 676 deaths (cancer, 226; cardiovascular disease, 142; other causes, 308). The prolonged sitting time was associated with a higher risk of all-cause and noncancer mortality, and vitamin D deficiency was associated with a higher risk of all-cause and cancer mortality. Furthermore, cancer survivors with both prolonged sitting time (≥ 6 h/day) and vitamin D deficiency had a significantly higher risk of all-cause (HR, 2.05; 95% CI: 1.54-2.72), cancer (HR, 2.33; 95% CI, 1.47-3.70), and noncancer mortality (HR, 1.91; 95% CI, 1.33-2.74) than those with neither risk factor after adjustment for potential confounders.CONCLUSIONS:In a nationally representative sample of U.S. cancer survivors, the joint presence of sedentary behavior and vitamin D deficiency was significantly associated with an increased risk of all-cause and cancer-specific mortality.

Sex differences in the nonlinear association of triglyceride glucose index with all-cause and cardiovascular mortality in the general population.

BACKGROUND:The evidence on the association between the triglyceride glucose (TyG) index and the risk of death in the general population remains controversial. This study aims to investigate the relationship between the TyG index and all-cause and cardiovascular mortality in the general population, with a focus on sex differences.METHODS:This prospective cohort study analyzed data from the National Health and Nutrition Examination Survey (1999-2002), comprising 7,851 US adults. The study employed multivariate Cox proportional hazards regression and two-segment Cox hazard regression models to evaluate the sex-specific differences in the relationship between the TyG index and all-cause and cardiovascular mortality.RESULTS:After 11,623 person-years of follow-up, there were 539 deaths, with 10.56% due to all-cause mortality and 2.87% due to cardiovascular mortality. After adjusting for multiple variables, our study found a U-shaped association of the TyG index with all-cause and cardiovascular mortality, with inflection points at 9.36 and 9.52. A significant sex difference was observed in the association between the TyG index and mortality. Below the inflection point, the relationship between the TyG index and mortality was consistent in males and females. However, above the inflection point, only males exhibited a positive association between the TyG index and all-cause mortality (adjusted hazard risk [HR], 1.62, 95% confidence interval [CI], 1.24-2.12) and cardiovascular mortality (adjusted HR, 2.28, 95% CI, 1.32-3.92).CONCLUSIONS:Our study showed a U-shaped association between the TyG index and all-cause and cardiovascular mortality in the general population. Furthermore, sex differences were observed in the association between the TyG index and mortality once it exceeded a certain threshold.

The impact of chronotropic incompetence on atrioventricular conduction times in heart failure patients.

BACKGROUND:Intrinsic atrioventricular (AV) conduction is used to optimize AV intervals with cardiac resynchronization therapy (CRT) in most device algorithms. Atrial pacing and heart rate affect conduction times, but little is known regarding differeces among chronotropic incompetent(CI) and competent(CC) patients to guide programming.METHODS:RAVE was a multicenter prospective trial of CRT patients. Heart rate was increased with incremental atrial pacing and with submaximal exercise. According to the maximal heart rate achieved during exercise, patients were classified as either CI or CC. For CI patients, an additional symptom-limited exercise with rate-adaptive pacing activated was performed. Intracardiac intervals were measured from the implantable lead electrograms in multiple postures.RESULTS:There were 12 subjects with CI and 24 with CC. With atrial pacing, AV interval immediately increased and gradually increased with incremental atrial pacing in all patients. However, the changes in the atrial to right ventricular (ARV) and atrial to left ventricular (ALV) intervals with increasing atrial pacing rates were about threefold greater in CI patients compared to CC patients (24.3 ± 28.9 vs. 7.2 ± 5.5 ms/10 bpm for ARV and 22.7 ± 25.6 vs. 7.1 ± 5.7 ms/10 bpm for ALV in the standing position, p < 0.05). In CI pacing with rate-adaptive pacing during exercise, AV interval changes with paced heart rate were variable.CONCLUSIONS:The AV response to overdrive atrial pacing at rest may provide a simple means of identifying chronotropic competence in CRT patients. For patients with CI, who often require rate-adaptive atrial pacing, rate-adaptive AV algorithms should be adjusted individually.

Letter regarding the article 'Clinical implications of left atrial changes after optimization of medical therapy in patients with heart failure'.

Clinical outcome of lesion size index-guided high-power radiofrequency catheter ablation for pulmonary vein isolation in patients with atrial fibrillation: 2-year follow-up.

INTRODUCTION:The long-term efficacy of high-power (50 W) ablation guided by lesion size index (LSI-guided HP) for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) remains undetermined. Our study sought to assess the clinical efficacy of LSI-guided HP ablation for PVI in patients with AF and explore the potential predictors associated with clinical outcomes.METHODS:We consecutively included 186 patients with AF who underwent LSI-guided HP (50 W) ablation at Fuwai Hospital from June 2019 to October 2021. The target LSI values of 4.5-5.5 and 4.0-4.5 at the anterior and posterior walls, respectively, were used in our study. The baseline clinical characteristics, procedural and ablation data, and clinical outcomes were evaluated. The independent potential predictors associated with AF recurrence were further evaluated.RESULTS:The incidence rate of first-pass PVI was 83.9% (156/186). A total of 11 883 lesions were analyzed, and compared with posterior walls of pulmonary veins, anterior walls had significantly lower mean contact force (8.2 ± 3.0 vs. 8.3 ± 2.3 g, p = .015), longer mean radiofrequency duration (16.9 ± 7.2 vs. 12.9 ± 4.5 s, p < .001) and higher mean LSI (4.8 ± 0.2 vs. 4.4 ± 0.2, p < .001). The overall incidence of periprocedural complications was 3.7%, and steam pops without pericardial effusion occurred in three patients (1.6%). During a mean follow-up of 24.0 ± 8.4 months, the overall AF recurrence-free survival was 87.1% after a single procedure. Patients with paroxysmal AF had a higher incidence of freedom from AF recurrence than those with persistent AF (91.2% vs. 80.8%, log-rank p = .034). Higher LSI (HR 0.50, p < .001) and paroxysmal AF (HR 0.39, p = .029) were significantly associated with decreased AF recurrence. By receiver operating characteristic analysis, the LSI of 4.7 and 4.3 for the anterior and posterior walls of the PVs had the highest predictive value for AF recurrence, respectively.CONCLUSION:LSI-guided HP (50 W) ablation for PVI was an efficient and safe strategy and led to favorable single-procedure 2-year AF recurrence-free survival in patients with AF. Higher LSI and paroxysmal AF were independent predictors of decreased 2-year AF recurrence. The LSI of 4.7 for the anterior wall and 4.3 for the posterior wall of the PVs were the best cutoff values for predicting AF recurrence after LSI-guided HP ablation.

Effectiveness of adding a defibrillator with cardiac resynchronization therapy in heart failure according to the modified Model for End-stage Liver Disease-Albumin score.

Current guidelines lack clear recommendations between the implantation of cardiac resynchronization therapy (CRT) with defibrillator (CRT-D) and CRT with pacemaker (CRT-P). We hypothesized that modified model for end-stage liver disease score including albumin (MELD-Albumin score), could be used to select patients who may not benefit from CRT-D. We consecutively included patients with CRT-P or CRT-D implantation between 2010 and 2022. The primary endpoint was the composite of all-cause mortality or worsening heart failure. We performed multivariable-adjusted Cox proportional hazard regression. We assessed the interaction between the MELD-Albumin score and the effect of adding a defibrillator with CRT.A total of 752 patients were included in this study, with 291 implanted CRT-P. During a median follow-up of 880 days, 205 patients reached the primary endpoint. MELD-Albumin score was significantly associated with the primary endpoint in the CRT-D group [HR 1.16 (1.09-1.24); P < 0.001] but not in the CRT-P group [HR 1.03 (0.95-1.12); P = 0.49]. There was a significant interaction between the MELD-Albumin score and the effect of CRTD (P = 0.013). The optimal cut-off value of the MELD-Albumin score was 12. For patients with MELD-Albumin ≥ 12, CRT-D was associated with a higher occurrence of the primary endpoint [HR 1.99 (1.10-3.58); P = 0.02], whereas not in patients with MELD-Albumin < 12 [HR 1.19 (0.83-1.70); P = 0.35). Our findings suggest that CRT-D is associated with an excess risk of composite clinical endpoints in HF patients with higher MELD-Albumin score.