Sudden cardiac death after myocardial infarction: individual participant data from pooled cohorts.

BACKGROUND AND AIMS: Risk stratification of sudden cardiac death after myocardial infarction and prevention by defibrillator rely on left ventricular ejection fraction (LVEF). Improved risk stratification across the whole LVEF range is required for decision-making on defibrillator implantation. METHODS: The analysis pooled 20 data sets with 140 204 post-myocardial infarction patients containing information on demographics, medical history, clinical characteristics, biomarkers, electrocardiography, echocardiography, and cardiac magnetic resonance imaging. Separate analyses were performed in patients (i) carrying a primary prevention cardioverter-defibrillator with LVEF ≤ 35% [implantable cardioverter-defibrillator (ICD) patients], (ii) without cardioverter-defibrillator with LVEF ≤ 35% (non-ICD patients ≤ 35%), and (iii) without cardioverter-defibrillator with LVEF > 35% (non-ICD patients >35%). Primary outcome was sudden cardiac death or, in defibrillator carriers, appropriate defibrillator therapy. Using a competing risk framework and systematic internal-external cross-validation, a model using LVEF only, a multivariable flexible parametric survival model, and a multivariable random forest survival model were developed and externally validated. Predictive performance was assessed by random effect meta-analysis. RESULTS: There were 1326 primary outcomes in 7543 ICD patients, 1193 in 25 058 non-ICD patients ≤35%, and 1567 in 107 603 non-ICD patients >35% during mean follow-up of 30.0, 46.5, and 57.6 months, respectively. In these three subgroups, LVEF poorly predicted sudden cardiac death (c-statistics between 0.50 and 0.56). Considering additional parameters did not improve calibration and discrimination, and model generalizability was poor. CONCLUSIONS: More accurate risk stratification for sudden cardiac death and identification of low-risk individuals with severely reduced LVEF or of high-risk individuals with preserved LVEF was not feasible, neither using LVEF nor using other predictors.

Implantable Cardioverter Defibrillator and Resynchronization Therapy in Patients With Overt Chronic Kidney Disease: JACC State-of-the-Art Review.

Heart failure and chronic kidney disease are common and clinically important conditions that regularly coexist. Electrophysiologic changes of advanced heart failure often result in abnormal conduction, causing dyssynchronous contraction, and development of ventricular arrhythmias, which can lead to sudden cardiac arrest. In the last 2 decades, implantable cardioverter-defibrillator and cardiac resynchronization therapy devices have been developed to address these complications. However, when the coexisting chronic kidney disease is advanced, the associated pathophysiologic cardiovascular changes can alter the efficacy and safety of those interventions and complicate the management. This review explores the impact of comorbid advanced heart failure and advanced chronic kidney disease on the efficacy and safety of implantable cardioverter-defibrillator and cardiac resynchronization therapy, the currently available evidence, and potential future directions.

Arrhythmic Risk Stratification by Cardiovascular Magnetic Resonance Imaging in Patients With Nonischemic Cardiomyopathy.

BACKGROUND: Myocardial fibrosis (MF) forms part of the arrhythmic substrate for ventricular arrhythmias (VAs). OBJECTIVES: This study sought to determine whether total myocardial fibrosis (TF) and gray zone fibrosis (GZF), assessed using cardiovascular magnetic resonance, are better than left ventricular ejection fraction (LVEF) in predicting ventricular arrhythmias in patients with nonischemic cardiomyopathy (NICM). METHODS: Patients with NICM in a derivation cohort (n = 866) and a validation cohort (n = 848) underwent quantification of TF and GZF. The primary composite endpoint was sudden cardiac death or VAs (ventricular fibrillation or ventricular tachycardia). RESULTS: The primary endpoint was met by 52 of 866 (6.0%) patients in the derivation cohort (median follow-up: 7.5 years; Q1-Q3: 5.2-9.3 years). In competing-risks analyses, MF on visual assessment (MFVA) predicted the primary endpoint (HR: 5.83; 95% CI: 3.15-10.8). Quantified MF measures permitted categorization into 3 risk groups: a TF of >0 g and ≤10 g was associated with an intermediate risk (HR: 4.03; 95% CI: 1.99-8.16), and a TF of >10 g was associated with the highest risk (HR: 9.17; 95% CI: 4.64-18.1) compared to patients with no MFVA (lowest risk). Similar trends were observed in the validation cohort. Categorization into these 3 risk groups was achievable using TF or GZF in combination or in isolation. In contrast, LVEF of <35% was a poor predictor of the primary endpoint (validation cohort HR: 1.99; 95% CI: 0.99-4.01). CONCLUSIONS: MFVA is a strong predictor of sudden cardiac death and VAs in NICM. TF and GZF mass added incremental value to MFVA. In contrast, LVEF was a poor discriminator of arrhythmic risk.

Challenging the status quo: a scoping review of value-based care models in cardiology and electrophysiology.

AIMS: The accomplishment of value-based healthcare (VBHC) models could save up to $1 trillion per year for healthcare systems worldwide while improving patients' wellbeing and experience. Nevertheless, its adoption and development are challenging. This review aims to provide an overview of current literature pertaining to the implementation of VBHC models used in cardiology, with a focus on cardiac electrophysiology. METHODS AND RESULTS: This scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis for Scoping Reviews. The records included in this publication were relevant documents published in PubMed, Mendeley, and ScienceDirect. The search criteria were publications about VBHC in the field of cardiology and electrophysiology published between 2006 and 2023. The implementation of VBHC models in cardiology and electrophysiology is still in its infant stages. There is a clear need to modify the current organizational structure in order to establish cross-functional teams with the patient at the centre of care. The adoption of new reimbursement schemes is crucial to moving this process forward. The implementation of technologies for data analysis and patient management, among others, poses challenges to the change process. CONCLUSION: New VBHC models have the potential to improve the care process and patient experience while optimizing the costs. The implementation of this model has been insufficient mainly because it requires substantial changes in the existing infrastructures and local organization, the need to track adherence to guidelines, and the evaluation of the quality of life improvement and patient satisfaction, among others.

Same-day discharge vs. overnight stay following catheter ablation for atrial fibrillation: a comprehensive review and meta-analysis by the European Heart Rhythm Association Health Economics Committee.

AIMS: Same-day discharge (SDD) after catheter ablation of atrial fibrillation (AF) may address the growing socio-economic health burden of the increasing demand for interventional AF therapies. This systematic review and meta-analysis analyses the current evidence on clinical outcomes in SDD after AF ablation compared with overnight stay (ONS). METHODS AND RESULTS: A systematic search of the PubMed database was performed. Pre-defined endpoints were complications at short-term (24-96 h) and 30-day post-discharge, re-hospitalization, and/or emergency room (ER) visits at 30-day post-discharge, and 30-day mortality. Twenty-four studies (154 716 patients) were included. Random-effects models were applied for meta-analyses of pooled endpoint prevalence in the SDD cohort and for comparison between SDD and ONS cohorts. Pooled estimates for complications after SDD were low both for short-term [2%; 95% confidence interval (CI): 1-5%; I2: 89%) and 30-day follow-up (2%; 95% CI: 1-4%; I2: 91%). There was no significant difference in complications rates between SDD and ONS [short-term: risk ratio (RR): 1.62; 95% CI: 0.52-5.01; I2: 37%; 30 days: RR: 0.65; 95% CI: 0.42-1.00; I2: 95%). Pooled rates of re-hospitalization/ER visits after SDD were 4% (95% CI: 1-10%; I2: 96%) with no statistically significant difference between SDD and ONS (RR: 0.86; 95% CI: 0.58-1.27; I2: 61%). Pooled 30-day mortality was low after SDD (0%; 95% CI: 0-1%; I2: 33%). All studies were subject to a relevant risk of bias, mainly due to study design. CONCLUSION: In this meta-analysis including a large contemporary cohort, SDD after AF ablation was associated with low prevalence of post-discharge complications, re-hospitalizations/ER visits and mortality, and a similar risk compared with ONS. Due to limited quality of current evidence, further prospective, randomized trials are needed to confirm safety of SDD and define patient- and procedure-related prerequisites for successful and safe SDD strategies.

Predictors of the efficacy of His bundle pacing in patients with a prolonged PR interval: A stratified analysis of the HOPE-HF randomized controlled trial.

AIMS: The randomized, double-blind, placebo-controlled HOPE-HF trial assessed the benefit of atrio-ventricular (AV) delay optimization delivered using His bundle pacing. It recruited patients with left ventricular ejection fraction ≤40%, PR interval ≥200 ms, and baseline QRS ≤140 ms or right bundle branch block. Overall, there was no significant increase in peak oxygen uptake (VO2max) but there was significant improvement in heart failure specific quality of life. In this pre-specified secondary analysis, we evaluated the impact of baseline PR interval, echocardiographic E-A fusion, and the magnitude of acute high-precision haemodynamic response to pacing, on outcomes. METHODS AND RESULTS: All 167 randomized participants underwent measurement of PR interval, acute haemodynamic response at optimized AV delay, and assessment of presence of E-A fusion. We tested the impact of these baseline parameters using a Bayesian ordinal model on VO2max, quality of life and activity measures. There was strong evidence of a beneficial interaction between the baseline acute haemodynamic response and the blinded benefit of pacing for VO2 (Pr 99.9%), Minnesota Living With Heart Failure (MLWHF) (Pr 99.8%), MLWHF physical limitation score (Pr 98.9%), EQ-5D visual analogue scale (Pr 99.6%), and exercise time (Pr 99.4%). The baseline PR interval and the presence of baseline E-A fusion did not have this reliable ability to predict the clinical benefit of pacing over placebo across multiple endpoints. CONCLUSIONS: In the HOPE-HF trial, the acute haemodynamic response to pacing reliably identified patients who obtained clinical benefit. Patients with a long PR interval (≥200 ms) and left ventricular impairment who obtained acute haemodynamic improvement with AV-optimized His bundle pacing were likely to obtain clinical benefit, consistent across multiple endpoints. Importantly, this gradation can be reliably tested for before randomization, but does require high-precision AV-optimized haemodynamic assessment to be performed.

Shared Decision-making in Breast Cancer Reconstructive Surgery: Experience in a Leading Hospital.

Background: The paradigm of healthcare has evolved toward patient-centered approaches, where shared decision-making (SDM) plays a pivotal role. This study aimed to explore the implementation of SDM during breast cancer reconstruction consultations and assess its impact on patient satisfaction and the decision-making process as a whole. Methods: A total of 102 female patients undergoing breast reconstruction were included in a multidisciplinary breast pathology unit. A streamlined SDM model involving choice introduction, option description, and preference exploration was implemented. A validated Spanish version of the nine-item Shared Decision Making Questionnaire was used alongside a complementary questionnaire. Data analysis was carried out using electronic data capture software. Results: The nine-item Shared Decision Making Questionnaire results indicate strong agreement in presenting various options and explaining their advantages and disadvantages. Patients were less confident about their participation in decision-making. The Complementary Shared Decision Making Questionnaire highlighted high satisfaction with interview times and language clarity but areas for improvement in consultation space and therapeutic choice participation. Conclusions: Integrating SDM into breast reconstruction consultations empowers patients in the decision-making process and enhances satisfaction. Decision aids prove effective in this context, facilitating patients' comprehension and reducing decisional conflict. There are areas for improvement within the SDM strategy, and they are detectable through scales. Although challenges in information transmission and patient involvement persist, adopting an SDM model has potential benefits that warrant further investigation.

Length of hospital stay for elective electrophysiological procedures: a survey from the European Heart Rhythm Association.

AIMS: Electrophysiological (EP) operations that have traditionally involved long hospital lengths of stay (LOS) are now being undertaken as day case procedures. The coronavirus disease-19 pandemic served as an impetus for many centres to shorten LOS for EP procedures. This survey explores LOS for elective EP procedures in the modern era. METHODS AND RESULTS: An online survey consisting of 27 multiple-choice questions was completed by 245 respondents from 35 countries. With respect to de novo cardiac implantable electronic device (CIED) implantations, day case procedures were reported for 79.5% of implantable loop recorders, 13.3% of pacemakers (PMs), 10.4% of implantable cardioverter defibrillators (ICDs), and 10.2% of cardiac resynchronization therapy (CRT) devices. With respect to CIED generator replacements, day case procedures were reported for 61.7% of PMs, 49.2% of ICDs, and 48.2% of CRT devices. With regard to ablations, day case procedures were reported for 5.7% of atrial fibrillation (AF) ablations, 10.7% of left-sided ablations, and 17.5% of right-sided ablations. A LOS ≥ 2 days for CIED implantation was reported for 47.7% of PM, 54.5% of ICDs, and 56.9% of CRT devices and for 54.5% of AF ablations, 42.2% of right-sided ablations, and 46.1% of left-sided ablations. Reimbursement (43-56%) and bed availability (20-47%) were reported to have no consistent impact on the organization of elective procedures. CONCLUSION: There is a wide variation in the LOS for elective EP procedures. The LOS for some procedures appears disproportionate to their complexity. Neither reimbursement nor bed availability consistently influenced LOS.

Diagnostic yield of a heart failure referral pathway using N-terminal pro-brain natriuretic peptide.

OBJECTIVE: To determine the diagnostic yield of a 'high' N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with suspected heart failure (HF) referred from primary to secondary care. METHODS: In this retrospective study, cardiac diagnoses were quantified in consecutive patients with an NT-proBNP>400 ng/L referred from primary care centres to a specialist HF service. RESULTS: Among 654 consecutive patients (age: 78.5±9.72 years; 45.9% men; left ventricular ejection fraction (LVEF): 55.4±12.5% (mean±SD)), the primary diagnoses were: valvular disease (39.4%), HF (29.2%; 13.3% with LVEF<40%) and atrial fibrillation (AF; 17.3%). In terms of primary or secondary diagnoses, 68% of patients had valve disease, 46.9% had AF and 29.2% had HF. A cardiac diagnosis was made in 85.9%. In multivariable analyses, NT-proBNP predicted HF with LVEF<40% (OR: 10.2, 95% CI: 5.63 to 18.3) and HF with any LVEF (OR: 6.13, 95% CI: 3.79 to 9.93). In canonical linear discriminant analyses, NT-proBNP correctly identified 54.5% of patients with HF. The remainder were misclassified as valvular disease, AF or no cardiac diagnosis. CONCLUSION: Among patients with an NT-proBNP>400 ng/L referred through a primary care HF pathway, most patients had valve disease or AF rather than HF. NT-proBNP cannot discriminate among HF, valve disease and AF. On this basis, NT-proBNP may be best employed in detecting cardiac disease in general rather than HF per se.

The evolving state of cardiac resynchronization therapy and conduction system pacing: 25 years of research at EP Europace journal.

Cardiac resynchronization therapy (CRT) was proposed in the 1990s as a new therapy for patients with heart failure and wide QRS with depressed left ventricular ejection fraction despite optimal medical treatment. This review is aimed first to describe the rationale and the physiologic effects of CRT. The journey of the landmark randomized trials leading to the adoption of CRT in the guidelines since 2005 is also reported showing the high level of evidence for CRT. Different alternative pacing modalities of CRT to conventional left ventricular pacing through the coronary sinus have been proposed to increase the response rate to CRT such as multisite pacing and endocardial pacing. A new emerging alternative technique to conventional biventricular pacing, conduction system pacing (CSP), is a promising therapy. The different modalities of CSP are described (Hirs pacing and left bundle branch area pacing). This new technique has to be evaluated in clinical randomized trials before implementation in the guidelines with a high level of evidence.

Improved prognosis after cardiac resynchronization therapy over a decade.

AIMS: The past decade has seen an increased delivery of cardiac resynchronization therapy (CRT) for patients with heart failure (HF). We explored whether clinical outcomes after CRT have changed from the perspective of an entire public healthcare system. METHODS AND RESULTS: A national database covering the population of England (56.3 million in 2019) was used to explore clinical outcomes after CRT from 2010 to 2019. A total of 64 698 consecutive patients (age 71.4 ± 11.7 years; 74.8% male) underwent CRT-defibrillation [n = 32 313 (49.7%)] or CRT-pacing [n = 32 655 (50.3%)] implantation. From 2010-2011 to 2018-2019, there was a 76% increase in CRT implantations. During the same period, the proportion of patients with hypertension (59.6-73.4%), diabetes (26.5-30.8%), and chronic kidney disease (8.62-22.5%) increased, as did the Charlson comorbidity index (CCI ≥ 3 from 20.0% to 25.1%) (all P < 0.001). Total mortality decreased at 30 days (1.43-1.09%) and 1 year (9.51-8.13%) after implantation (both P < 0.001). At 2 years, total mortality [hazard ratio (HR): 0.72; 95% confidence interval (CI) 0.69-0.76] and total mortality or HF hospitalization (HR: 0.59; 95% CI 0.57-0.62) decreased from 2010-2011 to 2018-2019, after correction for age, race, sex, device type (CRT-defibrillation or pacing), comorbidities (hypertension, diabetes, chronic kidney disease, and myocardial infarction), or the CCI (HR: 0.81; 95% CI 0.77-0.85). CONCLUSIONS: From the perspective of an entire public health system, survival has improved and HF hospitalizations have decreased after CRT implantation over the past decade. This prognostic improvement has occurred despite an increasing comorbidity burden.

Cardiac resynchronization therapy in adults with structural congenital heart disease and chronic heart failure.

AIMS: Evidence for CRT in adults with congenital heart disease (ACHD) and chronic heart failure is limited, with recommendations for its use extrapolated from the population with structurally normal hearts. This retrospective observational study investigates the efficacy of CRT in this heterogenous group, discussing factors predicting response to CRT. METHODS: Twenty-seven patients with structural ACHD who underwent CRT insertion or upgrade at a tertiary center in the United Kingdom were retrospectively studied. The primary outcome measure was clinical response to CRT, defined as improvement of NYHA class and/or improvement in systemic ventricular ejection fraction by one category. Secondary outcomes included change in QRS duration and adverse events. RESULTS: Thirty-seven percent of patients had a systemic right ventricle (sRV). RBBB was the commonest baseline QRS morphology (40.7%) despite this being an unfavorable characteristic for CRT. Overall, positive response to CRT was demonstrated in 18 patients (66.7%). NYHA class improved in 55.5% following CRT (p = .001) and 40.7% showed improvement in systemic ventricular ejection fraction (p = .118). There were no baseline characteristics that predicted response to CRT, and electrocardiographic measures such as QRS shortening post-CRT was not associated with positive response. Good response rates (60.0%) were demonstrated in those with sRV. CONCLUSION: CRT is efficacious in structural ACHD including in those who do not meet conventional criteria. Extrapolation of recommendations from adults with structurally normal hearts may be inappropriate. Future research should focus on improving patient selection for CRT, for example using techniques to better quantify mechanical dysynchrony and intra-procedural electrical activation mapping in these complex patients.

Safety, usability, and performance of a wireless left atrial pressure monitoring system in patients with heart failure: the VECTOR-HF trial.

AIMS: In heart failure (HF), implantable haemodynamic monitoring devices have been shown to optimize therapy, anticipating clinical decompensation and preventing hospitalization. Direct left-sided haemodynamic sensors offer theoretical benefits beyond pulmonary artery pressure monitoring systems. We evaluated the safety, usability, and performance of a novel left atrial pressure (LAP) monitoring system in HF patients. METHODS AND RESULTS: The VECTOR-HF study (NCT03775161) was a first-in-human, prospective, multicentre, single-arm, clinical trial enrolling 30 patients with HF. The device consisted of an interatrial positioned leadless sensor, able to transmit LAP data wirelessly. After 3 months, a right heart catheterization was performed to correlate mean pulmonary capillary wedge pressure (PCWP) with simultaneous mean LAP obtained from the device. Remote LAP measurements were then used to guide patient management. The miniaturized device was successfully implanted in all 30 patients, without acute major adverse cardiac and neurological events (MACNE). At 3 months, freedom from short-term MACNE was 97%. Agreement between sensor-calculated LAP and PCWP was consistent, with a mean difference of -0.22 ± 4.92 mmHg, the correlation coefficient and the Lin's concordance correlation coefficient values were equal to 0.79 (p < 0.0001) and 0.776 (95% confidence interval 0.582-0.886), respectively. Preliminary experience with V-LAP-based HF management was associated with significant improvements in New York Heart Association (NYHA) functional class (32% of patients reached NYHA class II at 6 months, p < 0.005; 60% of patients at 12 months, p < 0.005) and 6-min walk test distance (from 244.59 ± 119.59 m at baseline to 311.78 ± 129.88 m after 6 months, p < 0.05, and 343.95 ± 146.15 m after 12 months, p < 0.05). CONCLUSION: The V-LAP™ monitoring system proved to be generally safe and provided a good correlation with invasive PCWP. Initial evidence also suggests possible improvement in HF clinical symptoms.

Non-invasive three-dimensional electrical activation mapping to predict cardiac resynchronization therapy response: site of latest left ventricular activation relative to pacing site.

AIMS: Pacing remote from the latest electrically activated site (LEAS) in the left ventricle (LV) may diminish response to cardiac resynchronization therapy (CRT). We tested whether proximity of LV pacing site (LVPS) to LEAS, determined by non-invasive three-dimensional electrical activation mapping [electrocardiographic Imaging (ECGI)], increased likelihood of CRT response. METHODS AND RESULTS: Consecutive CRT patients underwent ECGI and chest/heart computed tomography 6-24 months of post-implant. Latest electrically activated site and the distance to LVPS (dp) were assessed. Left ventricular end-systolic volume (LVESV) reduction of ≥15% at clinical follow-up defined response. Logistic regression probabilistically modelled non-response; variables included demographics, heart failure classification, left bundle branch block (LBBB), ischaemic heart disease (IHD), atrial fibrillation, QRS duration, baseline ejection fraction (EF) and LVESV, comorbidities, use of CRT optimization algorithm, angiotensin-converting enzyme inhibitor(ACE)/angiotensin-receptor blocker (ARB), beta-blocker, diuretics, and dp. Of 111 studied patients [64 ± 11 years, EF 28 ± 6%, implant duration 12 ± 5 months (mean ± SD), 98% had LBBB, 38% IHD], 67% responded at 10 ± 3 months post CRT-implant. Latest electrically activated sites were outside the mid-to-basal lateral segments in 35% of the patients. dp was 42 ± 23 mm [31 ± 14 mm for responders vs. 63 ± 24 mm non-responders (P < 0.001)]. Longer dp and the lack of use of CRT optimization algorithm were the only independent predictors of non-response [area under the curve (AUC) 0.906]. dp of 47 mm delineated responders and non-responders (AUC 0.931). CONCLUSION: The distance between LV pacing site and latest electrical activation is a strong independent predictor for CRT response. Non-invasive electrical evaluation to characterize intrinsic activation and guide LV lead deployment may improve CRT efficacy.

Timing of cardiac resynchronization therapy implantation.

AIMS: The optimum timing of cardiac resynchronization therapy (CRT) implantation is unknown. We explored long-term outcomes after CRT in relation to the time interval from a first heart failure hospitalization (HFH) to device implantation. METHODS AND RESULTS: A database covering the population of England (56.3 million in 2019) was used to quantify clinical outcomes after CRT implantation in relation to first HFHs. From 2010 to 2019, 64 968 patients [age: 71.4 ± 11.7 years; 48 606 (74.8%) male] underwent CRT implantation, 57% in the absence of a previous HFH, 12.9% during the first HFH, and 30.1% after ≥1 HFH. Over 4.54 (2.80-6.71) years [median (interquartile range); 272 989 person-years], the time in years from the first HFH to CRT implantation was associated with a higher risk of total mortality [hazard ratio (HR); 95% confidence intervals (95% CI)] (1.15; 95% CI 1.14-1.16, HFH (HR: 1.26; 95% CI 1.24-1.28), and the combined endpoint of total mortality or HFH (HR: 1.19; 95% CI 1.27-1.20) than CRT in patients with no previous HFHs, after co-variate adjustment. Total mortality (HR: 1.67), HFH (HR: 2.63), and total mortality or HFH (HR: 1.92) (all P < 0.001) were highest in patients undergoing CRT ≥2 years after the first HFH. CONCLUSION: In this study of a healthcare system covering an entire nation, delays from a first HFH to CRT implantation were associated with progressively worse long-term clinical outcomes. The best clinical outcomes were observed in patients with no previous HFH and in those undergoing CRT implantation during the first HFH. CONDENSED ABSTRACT: The optimum timing of CRT implantation is unknown. In this study of 64 968 consecutive patients, delays from a first heart failure hospitalization (HFH) to CRT implantation were associated with progressively worse long-term clinical outcomes. Each year from a first HFH to CRT implantation was associated with a 21% higher risk of total mortality and a 34% higher risk of HFH. The best outcomes after CRT were observed in patients with no previous HFHs and in those undergoing implantation during their first HFH.

Successful Catheter Ablation of Ventricular Tachycardia Precipitated by Cardiac Resynchronization Therapy.

A patient with ischemic cardiomyopathy and an implantable cardioverter-defibrillator underwent an upgrade with an epicardial left ventricular lead, which precipitated recurrent ventricular tachycardia (VT). An electrophysiological study with electroanatomic mapping showed the site of the left ventricular lead to be part of the re-entrant circuit, and substrate modification of an endocardial channel led to the resolution of VT and an improvement in symptoms.

Comprehensive Phenotypic Characterization of Late Gadolinium Enhancement Predicts Sudden Cardiac Death in Coronary Artery Disease.

BACKGROUND: Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) offers the potential to noninvasively characterize the phenotypic substrate for sudden cardiac death (SCD). OBJECTIVES: The authors assessed the utility of infarct characterization by CMR, including scar microstructure analysis, to predict SCD in patients with coronary artery disease (CAD). METHODS: Patients with stable CAD were prospectively recruited into a CMR registry. LGE quantification of core infarction and the peri-infarct zone (PIZ) was performed alongside computational image analysis to extract morphologic and texture scar microstructure features. The primary outcome was SCD or aborted SCD. RESULTS: Of 437 patients (mean age: 64 years; mean left ventricular ejection fraction [LVEF]: 47%) followed for a median of 6.3 years, 49 patients (11.2%) experienced the primary outcome. On multivariable analysis, PIZ mass and core infarct mass were independently associated with the primary outcome (per gram: HR: 1.07 [95% CI: 1.02-1.12]; P = 0.002 and HR: 1.03 [95% CI: 1.01-1.05]; P = 0.01, respectively), and the addition of both parameters improved discrimination of the model (Harrell's C-statistic: 0.64-0.79). PIZ mass, however, did not provide incremental prognostic value over core infarct mass based on Harrell's C-statistic or risk reclassification analysis. Severely reduced LVEF did not predict the primary endpoint after adjustment for scar mass. On scar microstructure analysis, the number of LGE islands in addition to scar transmurality, radiality, interface area, and entropy were all associated with the primary outcome after adjustment for severely reduced LVEF and New York Heart Association functional class of >1. No scar microstructure feature remained associated with the primary endpoint when PIZ mass and core infarct mass were added to the regression models. CONCLUSIONS: Comprehensive LGE characterization independently predicted SCD risk beyond conventional predictors used in implantable cardioverter-defibrillator (ICD) insertion guidelines. These results signify the potential for a more personalized approach to determining ICD candidacy in CAD.

Declining Risk of Sudden Cardiac Death in Heart Failure: Fact or Myth?

The notion that the risk of sudden cardiac death (SCD) in patients with heart failure (HF) is declining seems to be gaining traction. Numerous editorials and commentaries have suggested that SCD, specifically arrhythmic SCD, is no longer a significant risk for patients with HF on guideline-directed medical therapy. In this review, we question whether the risk of SCD has indeed declined in HF trials and in the real world. We also explore whether, despite relative risk reductions, the residual SCD risk after guideline-directed medical therapy still suggests a need for implantable cardioverter defibrillator therapy. Among our arguments is that SCD has not decreased in HF trials, nor in the real world. Moreover, we argue that data from HF trials, which have not adhered to guideline-directed device therapy, do not obviate or justify delays to implantable cardioverter defibrillator therapy. In this context, we underline the challenges of translating the findings of HF randomized, controlled trials of guideline-directed medical therapy to the real world. We also make the case for HF trials that adhere to current guideline-directed device therapy so that we can better understand the role of implantable cardioverter defibrillators in chronic HF.

Worldwide survey on implantation of and outcomes for conduction system pacing with His bundle and left bundle branch area pacing leads.

BACKGROUND: Adoption and outcomes for conduction system pacing (CSP), which includes His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), in real-world settings are incompletely understood. We sought to describe real-world adoption of CSP lead implantation and subsequent outcomes. METHODS: We performed an online cross-sectional survey on the implantation and outcomes associated with CSP, between November 15, 2020, and February 15, 2021. We described survey responses and reported HBP and LBBAP outcomes for bradycardia pacing and cardiac resynchronization CRT indications, separately. RESULTS: The analysis cohort included 140 institutions, located on 5 continents, who contributed data to the worldwide survey on CSP. Of these, 127 institutions (90.7%) reported experience implanting CSP leads. CSP and overall device implantation volumes were reported by 84 institutions. In 2019, the median proportion of device implants with CSP, HBP, and/or LBBAP leads attempted were 4.4% (interquartile range [IQR], 1.9-12.5%; range, 0.4-100%), 3.3% (IQR, 1.3-7.1%; range, 0.2-87.0%), and 2.5% (IQR, 0.5-24.0%; range, 0.1-55.6%), respectively. For bradycardia pacing indications, HBP leads, as compared to LBBAP leads, had higher reported implant threshold (median [IQR]: 1.5 V [1.3-2.0 V] vs 0.8 V [0.6-1.0 V], p = 0.0008) and lower ventricular sensing (median [IQR]: 4.0 mV [3.0-5.0 mV] vs. 10.0 mV [7.0-12.0 mV], p < 0.0001). CONCLUSION: In conclusion, CSP lead implantation has been broadly adopted but has yet to become the default approach at most surveyed institutions. As the indications and data for CSP continue to evolve, strategies to educate and promote CSP lead implantation at institutions without CSP lead implantation experience would be necessary.

Laser Doppler flow for the hemodynamic differentiation of tachycardia.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) offer effective therapy for the prevention of sudden cardiac death (SCD) due to ventricular arrhythmias. However, inappropriate shocks have detrimental effects on survival and quality of life. The addition of hemodynamic monitoring may be useful in discriminating clinically important ventricular arrhythmias. OBJECTIVE: In this study, we assess the ability of laser Doppler flowmetry to assess the hemodynamic effect of paced atrial and ventricular arrhythmias using mean arterial blood pressure as the reference. METHODS: In this acute human study in patients undergoing an elective electrophysiological study, laser Doppler flowmetry, arterial blood pressure, and surface ECG were acquired during high-rate atrial and ventricular pacing to simulate supraventricular and ventricular tachycardias. RESULTS: Arterial blood pressure and laser Doppler flow signals correlated well during atrial and ventricular pacing (rho = 0.694, p < .001). The hemodynamic impairment detected by both methods was greater during ventricular pacing than atrial pacing (-1.0% vs. 19.0%, p < .001). Laser Doppler flowmetry performed better than rate alone to identify hemodynamic impairments. CONCLUSION: In this acute study, laser Doppler flowmetry tissue perfusion served as a good surrogate measure for arterial pressure, which could be incorporated into future ICDs.