Factors that Determined a Positive Response to Resynchronization Therapy in Patients With Chronic Heart Failure and Cardiac Dyssynchrony. One Center Experience.

AIM: To evaluate the efficacy of cardiac resynchronization therapy (CRT) in patients with chronic heart failure (CHF) associated with cardiac dyssynchrony and to identify the factors that influence the CRT efficacy. MATERIAL AND METHODS: This retrospective study included 155 patients after implantation of CRT devices. The CRT devices with a built-in cardioverter-defibrillator (CRT-D) and without it (CRT-P) were implanted in 139 (89.7%) and 16 (10.3%) patients, respectively. The follow-up period was 52.37±35.94 months. Based on the study results, two groups of patients were formed depending on the presence of a clinical response to CRT, responders and non-responders. The factors that influenced the clinical response to CRT were studied. The effect of the baseline state of patients on the effect of therapy was assessed. The need for CRT optimization and a possibility of using electrocardiographic criteria for that purpose were studied. Modern devices and leads for CRT, their functional capabilities and their influence on the CRT efficacy were characterized. Statistical analysis was performed with an IBM SPSS Statistics 21.0 (Chicago, USA) package. RESULTS: CRT implantation with the left ventricular lead placement according to the traditional technique, through the coronary sinus, was successful in 130 (87.9%) patients. Difficulties with the left ventricular lead placement were noted in 13 (8.3%) patients when other techniques were used. After 6 months, a hemodynamic and clinical response was observed in 112 (72.2%) patients, and no positive response in 43 (27.8%). The increase in left ventricular ejection fraction in the responder group was more than 21.8±3.7%, which was associated with an improvement of the 6-minute walk test results. Th clinical response was significantly influenced by the possibility of stimulation from the basal parts of the heart; the use of more modern devices for CRT and quadripolar left ventricular leads; timely CRT optimization; and persistent dyssynchrony in non-responders. During the follow-up period, 34 (21.9%) patients died. The death rate in the non-responder group was significantly higher than in the responder group, 18 (41.3%) vs. 16 (14.3%), p=0.001. The main cause of death in the group of non-responders was CHF. Heart transplantation was performed in 3 (1.9%) patients. CONCLUSION: CRT increases the life span and improves the quality of life in patients with CHF and cardiac dyssynchrony. There was a group of patients with no benefit from CRT in this study. Modern devices allow increasing the number of patients who benefit from CRT. Periodic optimization of CRT is necessary. When optimizing CRT, it is possible to use electrocardiographic criteria of effectiveness: duration of the QRS complex and changes in the position of the electrical axis of the heart.

A Novel Liver Fibrosis Marker FIB-5 Index Predicted Response to Cardiac Resynchronization Therapy and Prognostic Outcomes in Patients With Heart Failure.

BACKGROUND: The fibrosis-5 (FIB-5) index is a noninvasive marker for assessing the progression of liver fibrosis and predictor in patients with heart failure (HF). This study investigated the association between the FIB-5 index and response to cardiac resynchronization therapy (CRT) and evaluated its predictive value for prognosis. METHODS: In total, 203 patients who underwent CRT/CRT-defibrillator (CRT-D) implantation were retrospectively included. The FIB-5 index was calculated using blood samples obtained before and after CRT/CRT-D. Response to CRT was defined as a relative reduction in left ventricular end-systolic volume of ≥15% 6 months after CRT/CRT-D. We compared the prognosis after CRT/CRT-D between the groups according to the FIB-5 index. RESULTS: One hundred and twenty-three patients (61%) responded to CRT. The responder group demonstrated a significantly higher FIB-5 index than the nonresponder group (-2.76 ± 3.85 vs. -4.67 ± 3.29, p < 0.001). Receiver-operating characteristic analysis demonstrated that the area under the curve of the FIB-5 index was 0.660 with a cutoff value of -4.00 for responders. In multivariate analysis, FIB-5 index ≥ -4.00 was an independent predictor for CRT response (odds ratio: 3.665, p = 0.003), in addition to QRS duration ≥ 150 ms and echocardiographic dysynchrony. The FIB-5 index increased significantly after 6 months in the responder group but not in the nonresponder group. The FIB-5 index ≥ -4.00 group showed a significantly better prognosis for cardiac death, HF hospitalization, and composite endpoint than the FIB-5 index < -4.00 group. CONCLUSION: The FIB-5 index in addition to classical predictors may be a useful marker for predicting response to CRT.

Characterization of cardiac resynchronization therapy response through machine learning and personalized models.

INTRODUCTION: The characterization and selection of heart failure (HF) patients for cardiac resynchronization therapy (CRT) remain challenging, with around 30% non-responder rate despite following current guidelines. This study aims to propose a novel hybrid approach, integrating machine-learning and personalized models, to identify explainable phenogroups of HF patients and predict their CRT response. METHODS: The paper proposes the creation of a complete personalized model population based on preoperative CRT patient strain curves. Based on the parameters and features extracted from these personalized models, phenotypes of patients are identified thanks to a clustering algorithm and a random forest classification is provided. RESULTS: A close match was observed between the 162 experimental and simulated myocardial strain curves, with a mean RMSE of 4.48% (±1.08) for the 162 patients. Five phenogroups of personalized models were identified from the clustering, with response rates ranging from 52% to 94%. The classification results show a mean area under the curves (AUC) of 0.86 ± 0.06 and provided a feature importance analysis with 22 features selected. Results show both regional myocardial contractility (from 22.5% to 33.0%), tissue viability and electrical activation delays importance on CRT response for each HF patient (from 55.8 ms to 88.4 ms). DISCUSSION: The patient-specific model parameters' analysis provides an explainable interpretation of HF patient phenogroups in relation to physiological mechanisms that seem predictive of the CRT response. These novel combined approaches appear as promising tools to improve understanding of LV mechanical dyssynchrony for HF patient characterization and CRT selection.

Feasibility, safety and outcomes of conduction system pacing for bradycardia amongst the very elderly.

The impact of age (≥ 85 vs < 85 years) on clinical outcomes and pacemaker performance of conduction system pacing (CSP) compared to right ventricular pacing (RVP) were examined. Consecutive patients from a prospective, observational, multicenter study with pacemakers implanted for bradycardia were studied. The primary endpoint was a composite of heart failure (HF)-hospitalizations, pacing-induced cardiomyopathy requiring cardiac resynchronization therapy or all-cause mortality. Secondary endpoints were acutely successful CSP, absence of pacing-complications, optimal pacemaker performance defined as pacing thresholds < 2.5 V, R-wave amplitude ≥ 5 V and absence of complications, threshold stability (no increases of > 1 V) and persistence of His-Purkinje capture on follow-up. Among 984 patients (age 74.1 ± 11.2 years, 41% CSP, 16% ≥ 85 years), CSP was independently associated with reduced hazard of the primary endpoint compared to RVP, regardless of age-group (< 85 years: adjusted hazard ratio [AHR] 0.63, 95% confidence interval [CI] 0.40-0.98; ≥ 85 years: AHR 0.40, 95% CI 0.17-0.94). Among patients with CSP, age did not significantly impact the secondary endpoints of acute CSP success (86% vs 88%), pacing complications (19% vs 11%), optimal pacemaker performance (64% vs 69%), threshold stability (96% vs 96%) and persistent His-Purkinje capture (86% vs 91%) on follow-up (all p > 0.05). CSP improves clinical outcomes in all age-groups, without compromising procedural safety or pacemaker performance in the very elderly.

Benefits of upgrading right ventricular to biventricular pacing in heart failure patients with atrial fibrillation.

AIMS: Recommendations on cardiac resynchronization therapy (CRT) in patients with atrial fibrillation or flutter (AF) are based on less robust evidence than those in sinus rhythm (SR). We aimed to assess the efficacy of CRT upgrade in the BUDAPEST-CRT Upgrade trial population by their baseline rhythm. METHODS AND RESULTS: Heart failure patients with reduced ejection fraction (HFrEF) and previously implanted pacemaker (PM) or implantable cardioverter defibrillator (ICD) and ≥20% right ventricular (RV) pacing burden were randomized to CRT with defibrillator (CRT-D) upgrade (n = 215) or ICD (n = 145). Primary [HF hospitalization (HFH), all-cause mortality, or <15% reduction of left ventricular end-systolic volume] and secondary outcomes were investigated. At enrolment, 131 (36%) patients had AF, who had an increased risk for HFH as compared with those with SR [adjusted hazard ratio (aHR) 2.99; 95% confidence interval (CI) 1.26-7.13; P = 0.013]. The effect of CRT-D upgrade was similar in patients with AF as in those with SR [AF adjusted odds ratio (aOR) 0.06; 95% CI 0.02-0.17; P < 0.001; SR aOR 0.13; 95% CI 0.07-0.27; P < 0.001; interaction P = 0.29] during the mean follow-up time of 12.4 months. Also, it decreased the risk of HFH or all-cause mortality (aHR 0.33; 95% CI 0.16-0.70; P = 0.003; interaction P = 0.17) and improved the echocardiographic response (left ventricular end-diastolic volume difference -49.21 mL; 95% CI -69.10 to -29.32; P < 0.001; interaction P = 0.21). CONCLUSION: In HFrEF patients with AF and PM/ICD with high RV pacing burden, CRT-D upgrade decreased the risk of HFH and improved reverse remodelling when compared with ICD, similar to that seen in patients in SR.

Clinical Usefulness of the Active Fixation Quadripolar Left Ventricular Lead Compared With the Passive Fixation Quadripolar Lead in Cardiac Resynchronization Therapy.

BACKGROUND: This study compared the stability of the Medtronic Attain Stability Quad (ASQ), a novel quadripolar active fixation left ventricular (LV) lead with a side helix, to that of conventional quadripolar leads with passive fixation (non-ASQ) and evaluated their LV lead performance. METHODS AND RESULTS: In all, 183 consecutive patients (69 ASQ, 114 non-ASQ) who underwent cardiac resynchronization therapy (CRT) between January 2018 and June 2021 were enrolled. Complications, including elevated pacing capture threshold (PCT) levels, phrenic nerve stimulation (PNS), and LV lead dislodgement, were analyzed during the postimplantation period until the first outpatient visit after discharge. The frequency of LV lead-related complications was significantly lower in the ASQ than non-ASQ group (14% vs. 30%, respectively; P=0.019). Specifically, LV lead dislodgement occurred only in the non-ASQ group, and elevated PCT levels were significantly lower in the ASQ group (7% vs. 23%; P=0.007). Kaplan-Meier analysis confirmed a significantly lower incidence of LV lead-related complications in the ASQ group (log-rank P=0.005). Cox multivariable regression analysis showed a significant reduction in lead-related complications associated with ASQ (hazard ratio 0.44; 95% confidence interval 0.23-0.83; P=0.011). CONCLUSIONS: The ASQ group exhibited fewer LV lead-related complications requiring reintervention and setting changes than the non-ASQ group. Thus, the ASQ may be a favorable choice for CRT device implantation.

Clinical outcomes with cardiac resynchronization therapy in patients with Cardiac Sarcoidosis: A systematic review and proportional meta-analysis.

BACKGROUND: Cardiac sarcoidosis (CS) is an inflammatory condition that can present with heart failure (HF). Cardiac resynchronization therapy (CRT) is known to improve clinical outcomes for patients with left bundle branch block in the general HF population. However, data about the outcomes of CRT in CS is limited. METHODS: A systematic literature search was conducted using PubMed/Medline, Embase, and the Cochrane Library from inception to February 2024 to identify studies that reported clinical outcomes following the use of CRT in patients with CS. Data for outcomes was extracted, pooled, and analyzed. OpenMetaAnalyst was used for pooling untransformed proportions along with the corresponding 95 % confidence intervals (CIs). RESULTS: Five studies with a total of 176 CS patients who received CRT were included. The pooled incidence for all-cause mortality was 7.6 % (95 % CI: -3 % to 18 %), for HF-related hospitalizations 23.2 % (95 % CI: 2 % to 43 %), and for major adverse cerebral and cardiovascular events 27 % (95 % CI: 8 % to 45 %) after a mean follow-up of 60.1 (±48.7) months. The pooled left ventricular ejection fraction (LVEF) was 34.28 % (95 % CI: 29.88 % to 38.68 %) demonstrating an improvement of 3.75 % in LVEF from baseline LVEF of 30.58 % (95 % CI: 24.68 % to 36.48 %). The mean New York Heart Association (NYHA) functional class was 2.16 (95 % CI: 1.47 to 2.84) after CRT as compared to the baseline mean NYHA of 2.58 (95 % CI: 2.29 to 2.86). CONCLUSION: Although improvements were observed in LVEF and mean NYHA, mortality was high in CS patients with CRT.

Conduction System Pacing: Hope, Challenges, and the Journey Forward.

PURPOSE OF THE REVIEW: Cardiac pacing has evolved in recent years currently culminating in the specific stimulation of the cardiac conduction system (conduction system pacing, CSP). This review aims to provide a comprehensive overview of the available literature on CSP, focusing on a critical classification of studies comparing CSP with standard treatment in the two fields of pacing for bradycardia and cardiac resynchronization therapy in patients with heart failure. The article will also elaborate specific benefits and limitations associated with CSP modalities of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). RECENT FINDINGS: Based on a growing number of observational studies for different indications of pacing therapy, both CSP modalities investigated are advantageous over standard treatment in terms of narrowing the paced QRS complex and preserving or improving left ventricular systolic function. Less consistent evidence exists with regard to the improvement of heart failure-related rehospitalization rates or mortality, and effect sizes vary between HBP and LBBAP. LBBAP is superior over HBP in terms of lead measurements and procedural duration. With regard to all reported outcomes, evidence from large scale randomized controlled clinical trials (RCT) is still scarce. CSP has the potential to sustainably improve patient care in cardiac pacing therapy if patients are appropriately selected and limitations are considered. With this review, we offer not only a summary of existing data, but also an outlook on probable future developments in the field, as well as a detailed summary of upcoming RCTs that provide insights into how the journey of CSP continues.

[New pacing strategies for heart failure]. / Neue Pacing-Strategien bei Herzinsuffizienz.

In patients with a reduced left ventricular (LV) systolic function (ejection fraction < 35%) and a left bundle branch block with a QRS duration > 130 ms, cardiac resynchronization therapy (CRT) can contribute to an improvement in the quality of life and a reduction in mortality. The resynchronization is mostly achieved by pacing via an epicardial LV lead in the coronary sinus; however, this approach is often limited by the patient's venous anatomy and an increase in the stimulation threshold over time. In addition, up to 30% of patients do not respond to the intervention. New treatment approaches involve direct stimulation of the conduction system by pacing of the bundle of His or left bundle branch. This enables a more physiological propagation of the stimulus. Pacing of the left bundle branch is achieved by advancing the lead into the right ventricle and screwing it deep into the interventricular septum. Due to the relatively large target area of the left bundle branch the success rate is very high (currently > 90%). Observational studies have shown a greater reduction in the QRS duration, a more pronounced improvement in systolic function and a lower hospitalization rate for heart failure associated with conduction system pacing compared to CRT using a coronary sinus lead. These findings have been confirmed in small randomized trials. Therefore, the use of left bundle branch pacing should be considered not only as a bail out in the case of failed resynchronization using coronary sinus lead placement but increasingly also as an initial pacing strategy. The results of the first large randomized trials are expected to be released in late 2024.

LV cathode position in CRT recipients: How can we benefit from CMR?

BACKGROUND: Left ventricular lead positioning represents a key step in CRT optimization. However, evidence for its guidance based on specific topographical factors and related imaging techniques is sparse. OBJECTIVE: To analyze reverse remodeling (RR) and clinical events in CRT recipients based on LV cathode (LVC) position relative to latest mechanical activation (LMA) and scar as determined by cardiac magnetic resonance (CMR). METHODS: This is a retrospective single-center study of 68 consecutive Q-LV-guided CRT-D and CRT-P recipients. Through CMR-based 3D reconstructions overlayed on fluoroscopy images, LVCs were stratified as concordant, adjacent, or discordant to LMA (3 segments with latest and greatest radial strain) and scar (segments with >50% scar transmurality). The primary endpoint of RR (expressed as percentage ESV change) and secondary composite endpoint of HF hospitalizations, LVAD/heart transplant, or cardiovascular death were compared across categories. RESULTS: LVC proximity to LMA was associated with a progressive increase in RR (percentage ESV change: concordant -47.0 ± 5.9%, adjacent -31.4 ± 3.1%, discordant +0.4 ± 3.7%), while proximity to scar was associated with sharply decreasing RR (concordant +10.7 ± 12.9%, adjacent +0.3 ± 5.3%, discordant -31.3 ± 4.4%, no scar -35.4 ± 4.8%). 4 integrated classes of LVC position demonstrated a significant positive RR gradient the more optimal the category (class I -47.0 ± 5.9%, class II -34.9 ± 2.8%, class III -5.5 ± 4.3%, class IV + 3.4 ± 5.2%). Freedom from composite secondary endpoint of HF hospitalization, LVAD/heart transplant, or cardiovascular death confirmed these trends demonstrating significant differences across both integrated as well as individual LMA and scar categories. CONCLUSION: Integrated CMR-determined LVC position relative to LMA and scar stratifies response to CRT.

Heart Size Difference Drives Sex-Specific Response to Cardiac Resynchronization Therapy: A Post Hoc Analysis of the MORE-MPP CRT Trial.

BACKGROUND: Studies have reported that female sex predicts superior cardiac resynchronization therapy (CRT) response. One theory is that this association is related to smaller female heart size, thus increased relative dyssynchrony at a given QRS duration (QRSd). Our objective was to investigate the mechanisms of sex-specific CRT response relating to heart size, relative dyssynchrony, cardiomyopathy type, QRS morphology, and other patient characteristics. METHODS AND RESULTS: This is a post hoc analysis of the MORE-CRT MPP (More Response on Cardiac Resynchronization Therapy with Multipoint Pacing)  trial (n=3739, 28% women), with a subgroup analysis of patients with nonischemic cardiomyopathy and left bundle-branch block (n=1308, 41% women) to control for confounding characteristics. A multivariable analysis examined predictors of response to 6 months of conventional CRT, including sex and relative dyssynchrony, measured by QRSd/left ventricular end-diastolic volume (LVEDV). Women had a higher CRT response rate than men (70.1% versus 56.8%, P<0.0001). In subgroup analysis, regression analysis of the nonischemic cardiomyopathy left bundle-branch block subgroup identified QRSd/LVEDV, but not sex, as a modifier of CRT response (P<0.0039). QRSd/LVEDV was significantly higher in women (0.919) versus men (0.708, P<0.001). CRT response was 78% for female patients with QRSd/LVEDV greater than the median value, compared with 68% with QRSd/LVEDV less than the median value (P=0.012). The association between CRT response and QRSd/LVEDV was strongest at QRSd <150 ms. CONCLUSIONS: In the nonischemic cardiomyopathy left bundle-branch block population, increased relative dyssynchrony in women, who have smaller heart sizes than their male counterparts, is a driver of sex-specific CRT response, particularly at QRSd <150 ms. Women may benefit from CRT at a QRSd <130 ms, opening the debate on whether sex-specific QRSd cutoffs or QRS/LVEDV measurement should be incorporated into clinical guidelines.

Is conduction system pacing a panacea for pacemaker therapy?

INTRODUCTION: While supported by robust evidence and decades of clinical experience, right ventricular apical pacing for bradycardia is associated with a risk of progressive left ventricular dysfunction. Cardiac resynchronization therapy for heart failure with reduced ejection fraction can result in limited electrical resynchronization due to anatomical constraints and epicardial stimulation. In both settings, directly stimulating the conduction system below the atrio-ventricular node (either the bundle of His or the left bundle branch area) has potential to overcome these limitations. Conduction system pacing has met with considerable enthusiasm in view of the more physiological electrical conduction pattern, is rapidly becoming the preferred option of pacing for bradycardia, and is gaining momentum as an alternative to conventional biventricular pacing. AREAS COVERED: This article provides a review of the current efficacy and safety data for both people requiring treatment for bradycardia and the management of heart failure with conduction delay and discusses the possible future roles for conduction system pacing in routine clinical practice. EXPERT OPINION: Conduction system pacing might be the holy grail of pacemaker therapy without the disadvantages of current approaches. However, hypothesis and enthusiasm are no match for robust data, demonstrating at least equivalent efficacy and safety to standard approaches.

LVSP and LBBP Result in Similar or Improved LV Synchrony and Hemodynamics Compared to BVP.

BACKGROUND: The effect of left ventricular septal myocardial pacing (LVSP) and left bundle branch pacing (LBBP) on ventricular synchrony and left ventricular (LV) hemodynamic status is poorly understood. OBJECTIVES: The aim of this study was to investigate the impact of LVSP and LBBP vs biventricular pacing (BVP) on ventricular electrical synchrony and hemodynamic status in cardiac resynchronization therapy patients. METHODS: In cardiac resynchronization therapy candidates with LV conduction disease, ventricular synchrony was assessed by measuring QRS duration (QRSd) and using ultra-high-frequency electrocardiography. LV electrical dyssynchrony was assessed as the difference between the first activation in leads V1 to V8 to the last from leads V4 to V8. LV hemodynamic status was estimated using invasive systolic blood pressure measurement during multiple transitions between LBBP, LVSP, and BVP. RESULTS: A total of 35 patients with a mean LV ejection fraction of 29% and a mean QRSd of 168 ± 24 ms were included. Thirteen had ischemic cardiomyopathy. QRSd during BVP, LVSP, and LBBP was the same, but LBBP provided shorter LV electrical dyssynchrony than BVP (-10 ms; 95% CI: -16 to -4 ms; P = 0.001); the difference between LVSP and BVP was not significant (-5 ms; 95% CI: -12 to 1 ms; P = 0.10). LBBP was associated with higher systolic blood pressure than BVP (4%; 95% CI: 2%-5%; P < 0.001), whereas LVSP was not (1%; 95% CI: 0%-2%; P = 0.10). Hemodynamic differences during LBBP and LVSP vs BVP were more pronounced in nonischemic than ischemic patients. CONCLUSIONS: Ultra-high-frequency electrocardiography allowed the documentation of differences in LV synchrony between LBBP, LVSP, and BVP, which were not observed by measuring QRSd. LVSP provided the same LV synchrony and hemodynamic status as BVP, while LBBP was better than BVP in both.

Sex Differences in Left Bundle Branch Area Pacing Versus Biventricular Pacing for Cardiac Resynchronization Therapy.

BACKGROUND: Women respond more favorably to biventricular pacing (BIVP) than men. Sex differences in atrioventricular and interventricular conduction have been described in BIVP studies. Left bundle branch area pacing (LBBAP) offers advantages due to direct capture of the conduction system. We hypothesized that men could respond better to LBBAP than BIVP. OBJECTIVES: This study aims to describe the sex differences in response to LBBAP vs BIVP as the initial cardiac resynchronization therapy (CRT). METHODS: In this multicenter prospective registry, we included patients with left ventricular ejection fraction ≤35% and left bundle branch block or a left ventricular ejection fraction ≤40% with an expected right ventricular pacing exceeding 40% undergoing initial CRT with LBBAP or BIVP. The composite primary outcome was heart failure-related hospitalization and all-cause mortality. The primary safety outcome included all procedure-related complications. RESULTS: There was no significant difference in the primary outcome when comparing men and women receiving LBBAP (P = 0.46), whereas the primary outcome was less frequent in women in the BIVP group than men treated with BIVP (P = 0.03). The primary outcome occurred less frequently in men undergoing LBBAP (29.9%) compared to those treated with BIVP (46.5%) (P = 0.004). In women, the incidence of the primary endpoint was 24.14% in the LBBAP group and 36.2% in the BIVP group; however, this difference was not statistically significant (P = 0.23). Complication rates remained consistent across all groups. CONCLUSIONS: Men and women undergoing LBBAP for CRT had similar clinical outcomes. Men undergoing LBBAP showed a lower risk of heart failure-related hospitalizations and all-cause mortality compared to men undergoing BIVP, whereas there was no difference between LBBAP and BIVP in women.

Machine learning of ECG waveforms and cardiac magnetic resonance for response and survival after cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) can lead to marked symptom reduction and improved survival in selected patients with heart failure with reduced ejection fraction (HFrEF); however, many candidates for CRT based on clinical guidelines do not have a favorable response. A better way to identify patients expected to benefit from CRT that applies machine learning to accessible and cost-effective diagnostic tools such as the 12-lead electrocardiogram (ECG) could have a major impact on clinical care in HFrEF by helping providers personalize treatment strategies and avoid delays in initiation of other potentially beneficial treatments. This study addresses this need by demonstrating that a novel approach to ECG waveform analysis using functional principal component decomposition (FPCD) performs better than measures that require manual ECG analysis with the human eye and also at least as well as a previously validated but more expensive approach based on cardiac magnetic resonance (CMR). Analyses are based on five-fold cross validation of areas under the curve (AUCs) for CRT response and survival time after the CRT implant using Cox proportional hazards regression with stratification of groups using a Gaussian mixture model approach. Furthermore, FPCD and CMR predictors are shown to be independent, which demonstrates that the FPCD electrical findings and the CMR mechanical findings together provide a synergistic model for response and survival after CRT. In summary, this study provides a highly effective approach to prognostication after CRT in HFrEF using an accessible and inexpensive diagnostic test with a major expected impact on personalization of therapies.

[Treatment with cardiac electronic implantable devices]. / Therapie mit kardialen elektronischen implantierbaren Devices.

Cardiac device therapy provides not only treatment options for bradyarrhythmia but also advanced treatment for heart failure and preventive measures against sudden cardiac death. In heart failure treatment it enables synergistic reverse remodelling and reduces pharmacological side effects. Cardiac resynchronization therapy (CRT) has revolutionized the treatment of reduced left ventricular ejection fraction (LVEF) and left bundle branch block by decreasing the mortality and morbidity with improvement of the quality of life and resilience. Conduction system pacing (CSP) as an alternative method of physiological stimulation can improve heart function and reduce the risk of pacemaker-induced cardiomyopathy. Leadless pacers and subcutaneous/extravascular defibrillators offer less invasive options with lower complication rates. The prevention of infections through preoperative and postoperative strategies enhances the safety of these therapies.

Pulmonary artery pressure monitoring in chronic heart failure: effects across clinically relevant subgroups in the MONITOR-HF trial.

BACKGROUND AND AIMS: In patients with chronic heart failure (HF), the MONITOR-HF trial demonstrated the efficacy of pulmonary artery (PA)-guided HF therapy over standard of care in improving quality of life and reducing HF hospitalizations and mean PA pressure. This study aimed to evaluate the consistency of these benefits in relation to clinically relevant subgroups. METHODS: The effect of PA-guided HF therapy was evaluated in the MONITOR-HF trial among predefined subgroups based on age, sex, atrial fibrillation, diabetes mellitus, left ventricular ejection fraction, HF aetiology, cardiac resynchronization therapy, and implantable cardioverter defibrillator. Outcome measures were based upon significance in the main trial and included quality of life-, clinical-, and PA pressure endpoints, and were assessed for each subgroup. Differential effects in relation to the subgroups were assessed with interaction terms. Both unadjusted and multiple testing adjusted interaction terms were presented. RESULTS: The effects of PA monitoring on quality of life, clinical events, and PA pressure were consistent in the predefined subgroups, without any clinically relevant heterogeneity within or across all endpoint categories (all adjusted interaction P-values were non-significant). In the unadjusted analysis of the primary endpoint quality-of-life change, weak trends towards a less pronounced effect in older patients (Pinteraction = .03; adjusted Pinteraction = .33) and diabetics (Pinteraction = .01; adjusted Pinteraction = .06) were observed. However, these interaction effects did not persist after adjusting for multiple testing. CONCLUSIONS: This subgroup analysis confirmed the consistent benefits of PA-guided HF therapy observed in the MONITOR-HF trial across clinically relevant subgroups, highlighting its efficacy in improving quality of life, clinical, and PA pressure endpoints in chronic HF patients.