Global and regional cardiac dysfunction quantified by 18F-FDG PET scans can predict ventricular arrhythmia in patients with implantable cardioverter defibrillator.

BACKGROUND: A low appropriate therapy rate indicates that a minority of patients will benefit from their implantable cardioverter defibrillator (ICD). Quantitative measurements from 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) may predict ventricular arrhythmia (VA) occurrence after ICD placement. METHODS: We performed a prospective observational study and recruited patients who required ICD placement. Pre-procedure image scans were performed. Patients were followed up for VA occurrence. Associations between image results and VA were analyzed. RESULTS: In 51 patients (33 males, 53.9 ± 17.2 years) analyzed, 17 (33.3%) developed VA. Compared with patients without VA, patients with VA had significantly larger values in scar area (17.7 ± 12.4% vs. 7.0 ± 7.9%), phase standard deviation (51.4° ± 14.0° vs. 34.0° ± 15.0°), bandwidth (172.9° ± 39.8° vs. 128.7° ± 49.9°), sum thickening score (STS, 29.5 ± 11.1 vs. 17.8 ± 13.2), and sum motion score (42.9 ± 11.5 vs. 33.0 ± 19.0). Cox regression analysis and receiver operating characteristic curve analysis showed that scar size, dyssynchrony, and STS were associated with VA occurrence (HR, 4.956, 95% CI 1.70-14.46). CONCLUSION: Larger left ventricular scar burden, increased dyssynchrony, and higher STS quantified by 18F-FDG PET may indicate a higher VA incidence after ICD placement.

Electrical characteristics of pacing different portions of the His bundle in bradycardia patients.

AIMS: His-bundle pacing (HBP) can be achieved in either atrial-side HBP (aHBP) or ventricular-side HBP (vHBP). The study compared the pacing parameters and electrophysiological characteristics between aHBP and vHBP in bradycardia patients. METHODS AND RESULTS: Fifty patients undergoing HBP implantation assisted by visualization of the tricuspid valvular annulus (TVA) were enrolled. The HBP lead position was identified by TVA angiography. Twenty-five patients were assigned to undergo aHBP and compared with 25 patients who underwent vHBP primarily in a prospective and randomized fashion. Pacing parameters and echocardiography were routinely assessed at implant and 3-month follow-up. His-bundle pacing was successfully performed in 45 patients (90% success rate with 44.4% aHBP and 55.6% vHBP). The capture threshold was lower in vHBP than aHBP at implant (vHBP: 1.1 ± 0.5 vs. aHBP: 1.4 ± 0.4 V/1.0 ms, P = 0.014) and 3-month follow-up (vHBP: 0.8 ± 0.4 vs. aHBP: 1.7 ± 0.8 V/0.4 ms, P < 0.001). The R-wave amplitude was higher in vHBP than in aHBP at implant (vHBP: 4.5 ± 1.4 vs. aHBP: 2.0 ± 0.8 mV, P < 0.001) and at 3-month follow-up (vHBP: 4.4 ± 1.5 vs. aHBP: 1.8 ± 0.7 mV, P < 0.001). No procedure-related complications and aggravation of tricuspid valve regurgitation were observed in most patients and echocardiographic assessment of cardiac function remained in the normal range in all patients during the follow-up. CONCLUSION: This study demonstrates that vHBP features a low and stable pacing capture threshold and high R-wave amplitude, suggesting better pacing mode management and battery longevity can be achieved by HBP in the ventricular side.

A prognostic nomogram for event-free survival in patients with atrial fibrillation before cardiac resynchronization therapy.

BACKGROUND: Atrial fibrillation (AF), one of the most common comorbidities of heart failure (HF), is associated with worse long-term prognosis in HF patients receiving cardiac resynchronization therapy (CRT). However, there is still no convenient tool to identify CRT candidates with AF who are at high risk of mortality and hospitalization due to HF. METHODS: We included 152 consecutive patients with AF for CRT in our hospital from January 2009 to July 2019. Multiple imputation was used for missing values. With imputed datasets, a multivariate Cox regression model was performed for variable selection using the backward stepwise method to predict all-cause mortality and HF readmissions. A nomogram and nomogram-based scoring system were constructed from the selected predictors. Then, internal validation and calibration were achieved by the bootstrap method, deriving the corrected concordance index and calibration curves. Sensitivity analysis was also performed to validate our selected predictors. RESULTS: Five predictors were incorporated in the nomogram, including N-terminal pro brain natriuretic protein (NT-proBNP) > 1745 pg/mL, history of syncope, previous pulmonary hypertension, moderate or severe tricuspid regurgitation, thyroid-stimulating hormone (TSH) > 4 mIU/L. The concordance index (0.70, 95% CI 0.62-0.77), corrected concordance index (0.67, 95% CI 0.59-0.74) and calibration curve showed optimal discrimination and calibration of the established nomogram. A significant difference in overall event-free survival was recognized by the nomogram-derived scores for patients with high risk (> 50 points), intermediate risk (21-50 points) and low risk (0-20 points) before CRT. CONCLUSION: Our internally validated nomogram may be an applicable tool for the early risk stratification of CRT candidates with AF.

Visualization of tricuspid valve annulus for implantation of His bundle pacing in patients with symptomatic bradycardia.

BACKGROUND: His bundle pacing (HBP) is a physiological pacing modality, but HBP implantation remains a challenge. OBJECTIVE: This study explored the feasibility of using visualization of the tricuspid valve annulus (TVA) to locate the site for HBP. METHODS: During the lead placement in eight patients with symptomatic bradycardia, the TVA and tricuspid septal leaflet was revealed by contrast injection in the right ventricle under the fluoroscopic right anterior oblique view, and the target site for HBP was identified near the intersection of the tricuspid septal leaflet and the interventricular septum. On the basis of the imaging marker, the pacing lead was placed for HBP at either the atrial (aHBP) or ventricular side (vHBP). RESULTS: During the implantation, the pacing lead placement was attempted for aHBP in two patients, vHBP in five patients, and first for aHBP then vHBP in one patient. The aHBP was selective and had a capture threshold of 1.6 ± 0.5 V@ 1.0ms and R-wave amplitude of 1.2 ± 0.4 mV. Ventricular-side His bundle capture was selective in four patients and nonselective in two patients. The vHBP capture threshold was 0.8 ± 0.4 V@ 1.0ms (P < .05 vs aHBP) and R-wave amplitude was 4.1 ± 1.5 mV (P < .05 vs aHBP). At the final pacing programming of 3.0 V@ 1.0ms, vHBP was nonselective in all six patients and aHBP remained selective in two patients. Pacing parameters remained stable at 3 months. CONCLUSION: The location of the TVA and tricuspid septal leaflet revealed by right ventriculography can be used as a landmark to identify the HBP site.

Left bundle branch pacing from distal His-bundle region by tricuspid valve annulus angiography.

A 78-year-old man presenting with amaurosis was admitted to the outpatient clinic 1 week ago. His baseline electrocardiogram showed Mobitz type II atrioventricular block and right bundle branch block. The patient's heart rate from Holter was only 32 bpm and therefore the indication for pacemaker implantation.

Prolonged corrected QT interval in predicting atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: Corrected QT interval (QTc) on the electrocardiogram is a marker of ventricular repolarization. Recent studies have examined its value in predicting the occurrence of atrial fibrillation (AF). METHODS AND RESULTS: We conducted a meta-analysis to determine whether alterations in QTc interval are associated with an increased risk of incident AF. The PUBMED and EMBASE databases were searched for all studies that evaluated the incident AF associated with prolonged QTc interval published before December 2016. Sensitivity and subgroup analysis were subsequently performed. A total of six studies including eight data sets for prolonged QTc interval were eligible. Subjects with prolonged QTc interval as a categorical variable had a significantly higher risk of AF during follow-up (hazard ratio [HR]: 1.16; 95% confidence interval [CI], 1.09-1.24, I2  = 90%) based on Bazett formula. In continuous variable analysis, we found a statistically significant risk for AF (HR, 1.17; 95% CI, 1.09-1.25; I2  = 0) every 10-ms prolongation in QTc. AF type, QTc cut-off value, geographical location, follow-up duration, and study population may be the possible reasons for the significant heterogeneity among the studies. CONCLUSIONS: Prolonged QTc interval is associated with an increased risk of AF. And the potential mechanisms underlying this cause-and-effect relationship need further investigation.

Leucocyte telomere length and paroxysmal atrial fibrillation: A prospective cohort study and systematic review with meta-analysis.

BACKGROUND: Telomere length is a surrogate marker of biological aging. Whether telomere length predicts the risk of atrial fibrillation (AF) independently of biological aging is controversial. We conducted a cohort study to examine the relationship between telomere length and paroxysmal AF (PAF), followed by a systematic review and meta-analysis of the published literature, incorporating our own data. METHODS: DNA was extracted from peripheral blood. Leucocyte telomere length was measured by a real-time polymerase chain reaction-based method, normalized to a single copy gene, and presented as telomere/single gene ratio (t/s). RESULTS: A total of 100 non-AF patients and 50 PAF patients (mean age: 61.0 ± 9.4 and 64.0 ± 10.7 years, respectively) were included. T/s for subjects without AF tended to be shorter than for those with AF (0.21 [0.06-0.36] vs 0.28 [0.11-0.71], P = .077). T/s was associated with a 1.60-fold increase in the risk of AF but this was not significant (95% CI: 0.988-2.597, P = .056). Our meta-analysis confirms no difference in telomere length between AF and non-AF patients and t/s was not associated with higher risk of AF in multivariate analysis. CONCLUSIONS: Our prospective data showed that leucocyte telomere length was similar between AF and non-AF patients but was significantly longer in male patients with PAF than those without AF in our subgroup analysis. Our meta-analysis found that t/s did not predict AF. These findings support the notion that chronological aging, but not markers of biological aging, predicts the risk of AF.

Linear Ablation Following Pulmonary Vein Isolation in Patients with Atrial Fibrillation: A Meta-Analysis.

Previous studies have given conflicting data regarding the long-term adjunctive efficacy of linear lesions (LLs) on top of pulmonary vein isolation (PVI) as an ablation strategy in patients with atrial fibrillation (AF). The aim of this meta-analysis was to provide a detailed analysis of the available randomized controlled trials (RCTs) regarding the efficacy of LL following PVI in AF patients. Current databases were searched until October 2015. The primary outcome end point of the meta-analysis was recurrence of any symptomatic or documented episode of AF or atrial tachycardia after a single ablation procedure with or without the use of antiarrhythmic drugs. Ten RCTs with a total of 1,446 patients were included in the meta-analysis. The pooled analysis of five trials concerning persistent AF (PeAF) patients (400 in PVI plus LL group and 182 in PVI alone group) suggested that the addition of LL following PVI does not lead to a significant reduction in recurrent atrial tachyarrhythmias compared with PVI alone (relative ratio [RR] = 0.73, 95% confidence interval [CI]: 0.44-1.21, P = 0.22). Similarly, there was no incremental benefit of additional LL in long-term outcomes in paroxysmal AF (PAF) patients (RR = 0.85, 95% CI: 0.68-1.05, P = 0.13). Pooling the results of all eligible trials suggested that PVI plus LL compared with PVI alone significantly increased radiofrequency time (P = 0.0002), fluoroscopy time (P < 0.00001), and procedure time (P < 0.0001). This meta-analysis suggests that LL following PVI does not provide additional benefit to sinus rhythm maintenance in patients with PeAF and PAF.

Association of QTc Interval and V4-S Wave With Appropriate ICD Therapy in Hypertrophic Cardiomyopathy.

Background: Ventricular arrhythmias in patients with hypertrophic cardiomyopathy (HCM) may lead to sudden cardiac death (SCD). We aimed to investigate the relationship between electrocardiogram (ECG) indicators and the risk of appropriate implantable cardioverter-defibrillator (ICD) therapy in HCM. Methods: The HCM patients receiving ICD implantation were enrolled consecutively. QT interval correction (QTc) was calculated using Bazett's formula. Long or deep S wave in V4 lead was defined as duration time >50 ms and/or voltage amplitude >0.6 mV. The endpoint in our study was at least one ICD appropriate therapy triggered by ventricular tachyarrhythmia (VT) or ventricular fibrillation (VF), including anti-tachyarrhythmia pacing (ATP) and electrical shock. Results: A total of 149 patients with HCM (mean age 53 ± 14 years, male 69.8%) were studied. Appropriate ICD therapies occurred in 47 patients (31.5%) during a median follow-up of 2.9 years. Cox regression analysis showed that long or deep S wave in V4 lead [hazard ratio (HR) 1.955, 95% confidence interval (CI) 1.017-3.759, P = 0.045] and QTc interval (HR 1.014, 95% CI 1.008-1.021, P < 0.001) were independent risk factors for appropriate ICD therapy. The ROC showed that the optimal cut-off point value for the QTc interval to predict the appropriate ICD therapy was 464 ms, and the AUC was 0.658 (95% CI 0.544-0.762, P = 0.002). The AUC for S wave anomalies in V4 lead was 0.608 (95% CI 0.511-0.706, P = 0.034). We developed a new model that combined the QTc interval and S wave anomalies in V4 lead based on four patient groups. Patients with QTc ≥464 ms and long or deep V4-S wave had the highest risk of developing appropriate ICD therapy (log-rank P < 0.0001). After adding QTc interval and V4-S wave anomalies into the HCM-risk-SCD model, the prediction effect of the new model was significantly improved, and the NRI was 0.302. Conclusions: In this HCM cohort, QTc and S wave anomalies in V4 lead were found to be significant and strong predictors of the risk of appropriate ICD therapy. Patients with QTc ≥464 ms and long or deep S wave had the highest risk. After QTc interval and V4-S wave anomalies adding to the HCM-risk-SCD model, the prediction effect is significantly improved.

Comorbid Hypertension Reduces the Risk of Ventricular Arrhythmia in Chronic Heart Failure Patients with Implantable Cardioverter-Defibrillators.

AIMS: Low blood pressure (BP) has been shown to be associated with increased mortality in patients with chronic heart failure. This study was designed to evaluate the relationships between diagnosed hypertension and the risk of ventricular arrhythmia (VA) and all-cause death in chronic heart failure (CHF) patients with implantable cardioverter-defibrillators (ICD), including those with preserved left ventricular ejection fraction (HFpEF) and indication for ICD secondary prevention. We hypothesized that a stable hypertension status, along with an increasing BP level, is associated with a reduction in the risk of VA in this population, thereby limiting ICD efficacy. METHODS: We retrospectively enrolled 964 CHF patients, with hypertension diagnosis and hospitalized BP measurements obtained before ICD implantation. The primary outcome measure was defined as the composite of SCD, appropriate ICD therapy, and sustained VT. The secondary endpoint was time to death or heart transplantation (HTx). We performed multivariable Cox proportional hazard regression and entropy balancing to calculate weights to control for baseline imbalances with or without hypertension. The Fine-Gray subdistribution hazard model was used to confirm the results. The effect of random BP measurements on the primary outcome was illustrated in the Cox model with inverse probability weighting. RESULTS: The 964 patients had a mean (SD) age of 58.9 (13.1) years; 762 (79.0%) were men. During the interrogation follow-up [median 2.81 years (interquartile range: 1.32-5.27 years)], 380 patients (39.4%) reached the primary outcome. A total of 244 (45.2%) VA events in non-hypertension patients and 136 (32.1%) in hypertension patients were observed. A total of 202 (21.0%) patients died, and 31 (3.2%) patients underwent heart transplantation (incidence 5.89 per 100 person-years; 95% CI: 5.16-6.70 per 100 person-years) during a median survival follow-up of 4.5 (IQR 2.8-6.8) years. A lower cumulative incidence of VA events was observed in hypertension patients in the initial unadjusted Kaplan-Meier time-to-event analysis [hazard ratio (HR): 0.65, 95% confidence interval (CI): 0.53-0.80]. The protective effect was robust after entropy balancing (HR: 0.71, 95% CI: 0.56-0.89) and counting death as a competing risk (HR: 0.71, 95% CI: 0.51-1.00). Hypertension diagnosis did not associate with all-cause mortality in this population. Random systolic blood pressure was negatively associated with VA outcomes (p = 0.065). CONCLUSIONS: In hospitalized chronic heart failure patients with implantable cardioverter-defibrillators, the hypertension status and higher systolic blood pressure measurements are independently associated with a lower risk of combined endpoints of ventricular arrhythmia and sudden cardiac death but not with all-cause mortality. Randomized controlled trials are needed to confirm the protective effect of hypertension on ventricular arrhythmia in chronic heart failure patients.

Validation of an Arrhythmogenic Right Ventricular Cardiomyopathy Risk-Prediction Model in a Chinese Cohort.

BACKGROUND: The novel arrhythmogenic right ventricular cardiomyopathy (ARVC)-associated ventricular arrhythmias (VAs) risk-prediction model endorsed by Cadrin-Tourigny et al. was recently developed to estimate visual VA risk and was identified to be more effective for predicting ventricular events than the International Task Force Consensus (ITFC) criteria, and the Heart Rhythm Society (HRS) criteria. Data regarding its application in Asians are lacking. OBJECTIVES: We aimed to perform an external validation of this algorithm in the Chinese ARVC population. METHODS: The study enrolled 88 ARVC patients who received implantable cardioverter-defibrillator (ICD) from January 2005 to January 2020. The primary endpoint was appropriate ICD therapies. The novel prediction model was used to calculate a priori predicted VA risk that was compared with the observed rates. RESULTS: During a median follow-up of 3.9 years, 57 (64.8%) patients received the ICD therapy. Patients with implanted ICDs for primary prevention had non-significantly lower rates of ICD therapy than secondary prevention (5-year event rate: 0.46 (0.13-0.66) and 0.80 (0.64-0.89); log-rank p = 0.098). The validation study revealed the C-statistic of 0.833 (95% confidence interval (CI) 0.615-1.000), and the predicted and the observed patterns were similar in primary prevention patients (mean predicted-observed risk: -0.07 (95% CI -0.21, 0.09)). However, in secondary prevention patients, the C-statistic was 0.640 (95% CI 0.510-0.770) and the predicted risk was significantly underestimated (mean predicted-observed risk: -0.32 (95% CI -0.39, -0.24)). The recalibration analysis showed that the performance of the prediction model in secondary prevention patients was improved, with the mean predicted-observed risk of -0.04 (95% CI -0.10, 0.03). CONCLUSIONS: The novel risk-prediction model had a good fitness to predict arrhythmic risk in Asian ARVC patients for primary prevention, and for secondary prevention patients after recalibration of the baseline risk.

Mitral Regurgitation and Body Mass Index Increase the Predictability of Perioperative Bleeding in Anticoagulated Patients With Nonvalvular Atrial Fibrillation.

Background: Catheter ablation (CA) effectively restores sinus rhythm in atrial fibrillation (AF) but causes a short-term fluctuation in the coagulation state. Potential risk factors and better management during this perioperative period remain understudied. Methods: We consecutively included 940 patients with nonvalvular AF who received CA at Fuwai Hospital, Beijing, China. Patients were divided into two groups according to their bleeding status during 3 months' anticoagulation. Any adverse events related to bleeding in the 3 months were evaluated. The HAS-BLED score and ABC-bleeding score, as well as other potential factors, were explored to predict bleeding risk. Results: In this observational study, 8.0% and 0.9% of the whole population suffered from bleeding and thromboembolic events, respectively. After adjusting for known factors related to bleeding, mitral regurgitation (MR, p for trend <0.001) and body mass index (BMI, odds ratio (OR) = 0.920, 95% CI 0.852-0.993, p = 0.033) were the most significant ones. C-indexes of the HAS-BLED score and ABC-bleeding score for bleeding were 0.558 (0.492-0.624) and 0.585 (0.515-0.655), respectively. The incorporation of MR and BMI significantly improved the predictive value based on HAS-BLED score (C-index = 0.650, 95% CI 0.585-0.715, p = 0.004) and ABC-bleeding score (C-index = 0.671, 95% CI 0.611-0.731, p < 0.001). The relative risk of mild-moderate MR was 4.500 (95% CI 1.625-12.460) in patients with AF having HAS-BLED = 1 and 4.654 (95% CI 1.496-14.475) in HAS-BLED ≥ 2, while it was not observed in patients with HAS-BLED = 0 (p = 0.722). Conclusion: More severe MR and lower BMI are associated with a higher incidence of perioperative bleeding, which helps improve the predictability of increased individual bleeding risk of a patient with nonvalvular AF who has received CA therapy and oral anticoagulants.

Comparison of electrical characteristics and pacing parameters of pacing different parts of the His-Purkinje system in bradycardia patients.

PURPOSE: We aimed to evaluate the electrical characteristics and pacing parameters at different locations of His-Purkinje system pacing. METHODS: Patients who successfully underwent His-Purkinje system pacing with bradycardia indications from April 2018 to August 2019 were retrospectively analyzed according to the lead location confirmed by visualization of the tricuspid value annulus, postoperative echocardiography, and pacing electrocardiogram. The electrical characteristics and pacing parameters were compared among these patients. RESULTS: A total of 135 patients were retrospectively analyzed. Among them, 30 patients received atrial side HBP (aHBP group), 52 received ventricular side HBP (vHBP group), and 53 received left bundle branch pacing (LBBP group). The proportion of non-selective pacing was significantly lower in aHBP group (30.0%) than in vHBP (75.0%) and LBBP group (90.6%). LBBP had significantly shorter procedural and fluoroscopic duration than aHBP and vHBP. The capture threshold was significantly higher (1.07 ± 0.26 V/1.0 ms vs. 0.89 ± 0.22 V/1.0 ms vs. 0.77 ± 0.18 V/0.4 ms, P < 0.01, respectively), and the R-wave amplitude was significantly lower (3.71 ± 1.72 mV vs. 5.81 ± 2.37 mV vs. 10.27 ± 4.71 mV, P < 0.05 respectively) in aHBP group than those in the other two groups at implantation and during 3-month follow-up. No significant differences were observed in complications among groups during 3-month follow-up. CONCLUSION: VHBP and LBBP had better pacing performances than aHBP and might be more ideal pacing methods for bradycardia patients.

N-Terminal Pro-B-Type Natriuretic Peptide in Risk Stratification of Heart Failure Patients With Implantable Cardioverter-Defibrillator.

Background: The prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure (HF) is well-established. However, whether it could facilitate the risk stratification of HF patients with implantable cardioverter-defibrillator (ICD) is still unclear. Objective: To determine the associations between baseline NT-proBNP and outcomes of all-cause mortality and first appropriate shock due to sustained ventricular tachycardia/ventricular fibrillation (VT/VF) in ICD recipients. Methods and results: N-terminal pro-B-type natriuretic peptide was measured before ICD implant in 500 patients (mean age 60.2 ± 12.0 years; 415 (83.0%) men; 231 (46.2%) Non-ischemic dilated cardiomyopathy (DCM); 136 (27.2%) primary prevention). The median NT-proBNP was 854.3 pg/ml (interquartile range [IQR]: 402.0 to 1,817.8 pg/ml). We categorized NT-proBNP levels into quartiles and used a restricted cubic spline to evaluate its nonlinear association with outcomes. The incidence rates of mortality and first appropriate shock were 5.6 and 9.1%, respectively. After adjusting for confounding factors, multivariable Cox regression showed a rise in NT-proBNP was associated with an increased risk of all-cause mortality. Compared with the lowest quartile, the hazard ratios (HRs) with 95% CI across increasing quartiles were 1.77 (0.71, 4.43), 3.98 (1.71, 9.25), and 5.90 (2.43, 14.30) for NT-proBNP (p for trend < 0.001). A restricted cubic spline demonstrated a similar pattern with an inflection point found at 3,231.4 pg/ml, beyond which the increase in NT-proBNP was not associated with increased mortality (p for nonlinearity < 0.001). Fine-Gray regression was used to evaluate the association between NT-proBNP and first appropriate shock accounting for the competing risk of death. In the unadjusted, partial, and fully adjusted analysis, however, no significant association could be found regardless of NT-proBNP as a categorical variable or log-transformed continuous variable (all p > 0.05). No nonlinearity was found, either (p = 0.666). Interactions between NT-proBNP and predefined factors were not found (all p > 0.1). Conclusion: In HF patients with ICD, the rise in NT-proBNP is independently associated with increased mortality until it reaches the inflection point. However, its association with the first appropriate shock was not found. Patients with higher NT-proBNP levels might derive less benefit from ICD implant.

Nomogram predicting death and heart transplantation before appropriate ICD shock in dilated cardiomyopathy.

AIMS: This study aimed to develop and validate a competing risk nomogram for predicting all-cause mortality and heart transplantation (HT) before first appropriate shock in non-ischaemic dilated cardiomyopathy (DCM) patients receiving implantable cardioverter-defibrillators (ICD). METHODS AND RESULTS: A total of 218 consecutive DCM patients implanted with ICD between 2010 and 2019 at our institution were retrospectively enrolled. Cox proportional hazards model was primarily built to identify variables associated with death and HT. Then, a Fine-Gray model, accounting for the appropriate shock as a competing risk, was constructed using these selected variables along with implantation indication (primary vs. secondary). Finally, a nomogram based on the Fine-Gray model was established to predict 1-, 3-, and 5-year probabilities of all-cause mortality and HT before first appropriate shock. The area under the receiver operating characteristic (ROC) curve (AUC), Harrell's C-index, and calibration curves were used to evaluate and internally validate the performance of this model. The decision curve analysis was applied to assess its clinical utility. The 1-, 3-, and 5-year cumulative incidence of all-cause mortality and HT without former appropriate shock were 5.3% [95% confidence interval (CI) 2.9-9.9%], 16.6% (95% CI 11-25.0%), and 25.3% (95% CI 17.2-37.1%), respectively. Five variables including implantation indication, left ventricular end-diastolic diameter, N-terminal pro-brain natriuretic peptide, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and amiodarone treatment were independently associated with it (all P < 0.05) and were used for constructing the nomogram. The 1-, 3-, and 5-year AUC of the nomogram were 0.83 (95% CI 0.73-0.94, P < 0.001), 0.84 (95% CI 0.75-0.93, P < 0.001), and 0.85 (95% CI 0.77-0.94, P < 0.001), respectively. The Harrell's C-index was 0.788 (95% CI 0.697-0.877, P < 0.001; 0.762 for the optimism-corrected C-index), showing the good discriminative ability of the model. The calibration was acceptable (optimism-corrected slope 0.896). Decision curve analysis identified our model was clinically useful within the entire range of potential treatment thresholds for ICD implantation. Three risk groups stratified by scores were significantly different between cumulative incidence curves (P < 0.001). The identified high-risk group composed 17.9% of our population and did not derive long-term benefit from ICD. CONCLUSIONS: The proposed nomogram is a simple, useful risk stratification tool for selecting potential ICD recipients in DCM patients. It might facilitate the shared decision-making between patients and clinicians.

Sacubitril/Valsartan in the Management of Heart Failure Patients with Cardiac Implantable Electronic Devices.

For heart failure patients with cardiac implantable electronic devices (CIEDs), especially those who remain symptomatic after implantation, the best management strategy is still unclear. Although there are several concerns regarding the clinical utilization of sacubitril/valsartan, it has improved the prognosis of patients with heart failure compared with the use of renin-angiotensin system inhibitors in recent years. Recent real-world observational studies and post hoc analyses demonstrated that sacubitril/valsartan might have effects in patients with CIEDs. Given its potential underlying mechanisms, sacubitril/valsartan could improve outcomes of mortality and sudden cardiac death incidence, as well as clinical and echocardiographic evaluations. The possible antiarrhythmic effect of sacubitril/valsartan is still debated. Moreover, given that hypotension is the critical limitation of uptitration, the rise in systolic blood pressure attributed to cardiac resynchronization therapy might support the use of sacubitril/valsartan, with improved tolerance. The clinical utility of sacubitril/valsartan in heart failure patients with CIEDs requires further investigation to determine the actual effects, optimal target populations, and underlying mechanisms.

Prognostic effects of longitudinal changes in left ventricular ejection fraction with cardiac resynchronization therapy.

AIMS: Left ventricular ejection fraction (LVEF) is considered an indicator of cardiac resynchronization therapy (CRT). Longitudinal studies on the predictive value of LVEF are scarce. We aimed to comprehensively evaluate the prognostic role of LVEF in the outcomes of Chinese patients with CRT. METHODS AND RESULTS: Three hundred ninety-two patients were divided into three tertiles of LVEF: ≤25%, 25-30%, and 30-35%, and four groups by LVEF changes: <0% (negative response); ≥0% and ≤5% (non-response); >5% and ≤15% (response); and >15% (super-response). One hundred six patients were super-responders. During a median follow-up of 3.6 years, 141 reached the composite endpoint. Odds ratios (ORs) for super-response depicted a reversed U-shaped relationship for baseline LVEF with a peak at 25-30%. Independent predictors of super-response were smaller left atrial diameter [odds ratio 0.897, 95% confidence interval (CI) 0.844-0.955, P = 0.001], smaller left ventricular end-diastolic diameter (OR 0.937, 95% CI 0.889-0.989, P = 0.018), and higher estimated glomerular filtration rate (OR 1.018, 95% CI 1.001-1.035, P = 0.042) in Tertile 1; atrial fibrillation (OR 0.278, 95% CI 0.086-0.901, P = 0.033), left bundle branch block (OR 4.096, 95% CI 1.046-16.037, P = 0.043), and left ventricular end-diastolic diameter (OR 0.929, 95% CI 0.876-0.986, P = 0.016) in Tertile 2; while female sex (OR 2.778, 95% CI 1.082-7.132, P = 0.034) and higher systolic blood pressure (OR 1.045, 95% CI 1.013-1.079, P = 0.006) in Tertile 3. An inverse association with the composite endpoint was found in Tertile 1 vs. Tertile 2 (hazard ratio 1.934, 95% CI 1.248-2.996, P = 0.003). The prognostic effects of CRT response in Tertile 3 and Tertile 1 varied significantly (P for trend = 0.017 and <0.001). Among three tertiles in super-responders, event-free survival was similar (P for trend = 0.143). CONCLUSIONS: Left ventricular ejection fraction of 25-30% is associated with a better prognosis of super-response. Predictors of super-response are different for LVEF tertiles. CRT responses would have better prognostic performance than LVEF tertiles at baseline, which should be considered when clinicians screening eligible patients for CRT.

Left ventricular involvement assessed by LGE-CMR in predicting the risk of adverse outcomes of arrhythmogenic cardiomyopathy with ICDs.

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is characterized by a high incidence of ventricular tachyarrhythmia and sudden death. Implantable cardioverter-defibrillator (ICD) implantation is the cornerstone of management. OBJECTIVE: This study aims to reveal the prognostic value of the contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) amount in predicting varying lethal outcomes among ACM patients with ICDs. METHODS: The 88 patients with definite ACM who were all referred for contrast-enhanced CMR received an ICD and were followed up for a median of 4.0 years. RESULTS: Fifty-four patients had no left ventricular (LV) involvement and sixteen had an LV LGE amount > 15%. During the follow-up time, appropriate ICD therapy was seen in 57, electrical storm (ES) in 19, and cardiac death in 9 patients. Compared with those without LV involvement, patients with LV LGE amount > 15% had a higher risk of cardiac death (log-rank P = 0.021). LV LGE amount was associated with an increased risk of ICD therapy [adjusted hazard ratio (HR) 1.035, 95% confidence interval (CI) 1.008-1.062, P = 0.010], and cardiac death (adjusted HR 1.082, 95% 1.006-1.164, P = 0.034), independently of LV ejection fraction. LV LGE mass of >15% demonstrated an over 2-fold increase in ICD therapy (adjusted HR 2.180, 95%CI 1.058-4.488, P = 0.035) and an over 7-fold increase in cardiac death (unadjusted HR 7.198, 95%CI 1.399-37.043, P = 0.018) than those without LV involvement, respectively. CONCLUSIONS: The LV LGE-CMR in ACM shows a dose-dependent association with ICD therapy and cardiac death. And LV LGE amount of >15% is a strong predictor.

Comparison between his-bundle pacing and left bundle branch pacing in patients with atrioventricular block.

BACKGROUND: Pacing the cardiac conduction system has been explored in patients with conduction system disease, but comprehensive comparisons between different pacing modalities are not well investigated. OBJECTIVE: To compare pacing characteristics and ventricular synchrony between His-bundle pacing (HBP) and left bundle branch pacing (LBBP) in patients with atrioventricular block (AVB). METHODS: Fifty pacemaker-indicated patients with AVB were enrolled. Twenty-five patients underwent HBP, and another 25 patients underwent LBBP. Success rate, procedural and fluoroscopy duration, pacing parameters, and echocardiographic data were perioperatively assessed and at 3-month follow-up. RESULTS: HBP was successful in 19 of 25 (76.0%) patients, whereas LBBP was successful in 22 of 25 (88.0%) patients. Compared with HBP, LBBP capture threshold was significantly lower (0.76 ± 0.25 V/0.4 ms vs. 1.27 ± 0.61 V/1.0 ms, P = 0.003) and R-wave amplitude was significantly higher with LBBP (11.7 ± 6.6 vs. 4.9 ± 2.4 mV, P < 0.001) at implant. The mean procedural time (74.3 ± 17.8 vs. 63.2 ± 12.3 min, P = 0.029) and fluoroscopy duration (10.3 ± 4.5 vs. 6.8 ± 2.2 min, P = 0.005) were significantly longer in the HBP group compared to LBBP. At 3-month follow-up, pacing capture threshold remained more stable in LBBP than in HBP group while left ventricular synchrony was similar between both groups. CONCLUSION: Despite similar impact on ventricular synchrony compared with HBP, LBBP featured a significantly lower pacing capture threshold, higher R-wave amplitude, and less time to achieve similar success rate in patients with AVB. These findings indicate LBBP as a physiological pacing strategy for AVB patients.