Arrhythmogenic Cardiomyopathy: Current Updates and Future Challenges.

Arrhythmogenic cardiomyopathy (ACM) epitomises a genetic anomaly hallmarked by a relentless fibro-fatty transmogrification of cardiac myocytes. Initially typified as a right ventricular-centric disease, contemporary observations elucidate a frequent occurrence of biventricular and left-dominant presentations. The diagnostic labyrinth of ACM emerges from its clinical and imaging properties, often indistinguishable from other cardiomyopathies. Precision in diagnosis, however, is paramount and unlocks the potential for early therapeutic interventions and vital cascade screening for at-risk individuals. Adherence to the criteria established by the 2010 task force remains the cornerstone of ACM diagnosis, demanding a multifaceted assessment incorporating electrophysiological, imaging, genetic, and histological data. Reflecting the evolution of our understanding, these criteria have undergone several revisions to encapsulate the expanding spectrum of ACM phenotypes. This review seeks to crystallise the genetic foundation of ACM, delineate its clinical and radiographic manifestations, and offer an analytical perspective on the current diagnostic criteria. By synthesising these elements, we aim to furnish practitioners with a strategic, evidence-based algorithm to accurately diagnose ACM, thereby optimising patient management and mitigating the intricate challenges of this multifaceted disorder.

Persistent Prothrombotic State in a Patient With Alström Syndrome.

We present the case of a patient with Alström syndrome who was found to have evidence of a prothrombotic state on autopsy after sudden cardiac death. To the best of our knowledge, this case of persistent prothrombotic milieu is the first described in a patient with Alström syndrome.

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.

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.

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.

Outcomes after transvenous defibrillator implantation in cardiac sarcoidosis: A systematic review.

Introduction: Sarcoidosis is a systemic inflammatory disorder associated with ventricular arrhythmias (VAs) and sudden death in the context of cardiac involvement. Guidelines advocate implantable cardioverter-defibrillator (ICD) implantation in specific subcohorts, but there is a paucity of data on outcomes. Methods and Results: A systematic review was performed to assess outcomes in patients with definite or probable cardiac sarcoidosis (CS) treated with ICD. Observational studies were identified from multiple databases from inception to 21st May 2021. Outcomes of interest included appropriate and inappropriate ICD therapies in addition to all-cause mortality. Study quality was assessed individually using the Newcastle Ottawa Scale (NOS).Eight studies were identified comprising 530 patients, with follow-up period of 24-66 months (weighted average 40 months). Mean age was 53.9 years with ejection fraction of 41.3%. Overall incidence of appropriate therapy was 38.1% during follow-up. Left ventricular systolic dysfunction (LVSD) with ejection fraction <40% was a predictor of appropriate therapy in the majority of studies, as were sustained VAs during electrophysiological testing (EP) in one study. There was no interaction with device indication (i.e. primary or secondary). Where documented, inappropriate therapy was primarily driven by atrial arrhythmias. All-cause mortality was 6.0% over a median follow-up period of 42 months. Only three studies achieved good quality in the comparability domain of NOS. Conclusions: Appropriate ICD therapy in patients with CS is commonly associated with LVSD, which can act as a surrogate for scar burden. The utility of EP testing in this setting remains unclear.

A real-world experience of subcutaneous and transvenous implantable cardiac defibrillators-comparison with the PRAETORIAN study.

Background: PRAETORIAN is the first randomized controlled trial that demonstrated the noninferiority of subcutaneous ICD (S-ICD) in comparison with transvenous ICD (TV-ICD). We retrospectively reviewed electronic records of patients with ICD implanted over the past 6 years, with the primary objective to compare our real-world single tertiary center experience with the randomized data from the PRAETORIAN study. Methods: Seventy S-ICD patients were compared with 197 TV-ICD patients, from July 2014 to June 2020 retrospectively, over a median period of 1304 days (296-2451 days). Primary composite endpoints included inappropriate shocks and device-related malfunctions. Results: Patients with S-ICD implantation were younger than those who received TV-ICD (mean, 49.7 years vs 63.9 years, p < .001). About 31.4% of S-ICDs were implanted for secondary prevention, and 58.6% of S-ICD patients had ischemic cardiomyopathy (ICM) with a median left ventricular ejection fraction of 32.5% (range: 10-67%). S-ICDs and TV-ICD had statistically similar inappropriate shocks (4.3% vs 4.6%, p = .78), device-related complications (11.4% vs 9.1%, p = .93), and the overall primary endpoints (15.7% vs 13.7%, p = .68). The findings remained the same even after age and gender adjustments and time-dependent analysis. Conclusion: Although single-center experience with a small number of S-ICD patients, results of the PRAETORIAN study has been replicated in our real-world experience of S-ICD and TV-ICD implantations across diverse etiologies, indications, and age groups confirming the comparable performance of S-ICD and TV-ICD when implanted in selected patients.

Incidence and Predictors of Implantable Cardioverter-defibrillator Therapies After Generator Replacement-A Pooled Analysis of 31,640 Patients' Data.

Among primary prevention implantable cardioverter-defibrillator (ICD) recipients, 75% do not experience any appropriate ICD therapies during their lifetime, and nearly 25% have improvements in their left ventricular ejection fraction (LVEF) during the lifespan of their first generator. The practice guidelines concerning this subgroup's clinical need for generator replacement (GR) remain unclear. We conducted a proportional meta-analysis to determine the incidence and predictors of ICD therapies after GR and compared this to the immediate and long-term complications. A systematic review of existing literature on ICD GR was performed. Selected studies were critically appraised using the Newcastle-Ottawa scale. Outcomes data were analyzed by random-effects modeling using R (R Foundation for Statistical Computing, Vienna, Austria), and covariate analyses were conducted using the restricted maximum likelihood function. A total of 31,640 patients across 20 studies were included in the meta-analysis with a median (range) follow-up of 2.9 (1.2-8.1) years. The incidences of total therapies, appropriate shocks, and anti-tachycardia pacing post-GR were approximately 8, 4, and 5 per 100 patient-years, respectively, corresponding to 22%, 12%, and 12% of patients of the total cohort, with a high level of heterogeneity across the studies. Greater anti-arrhythmic drug use and previous shocks were associated with ICD therapies post-GR. The all-cause mortality was approximately 6 per 100 patient-years, corresponding to 17% of the cohort. Diabetes mellitus, atrial fibrillation, ischemic cardiomyopathy, and the use of digoxin were predictors of all-cause mortality in the univariate analysis; however, none of these were found to be significant predictors in the multivariate analysis. The incidences of inappropriate shocks and other procedural complications were 2 and 2 per 100 patient-years, respectively, which corresponded to 6% and 4% of the entire cohort. Patients undergoing ICD GR continue to require therapy in a significant proportion of cases without any correlation with an improvement in LVEF. Further prospective studies are necessary to risk-stratify ICD patients undergoing GR.

Advanced care planning during the COVID-19 pandemic: ceiling of care decisions and their implications for observational data.

BACKGROUND: Observational studies investigating risk factors in coronavirus disease 2019 (COVID-19) have not considered the confounding effects of advanced care planning, such that a valid picture of risk for elderly, frail and multi-morbid patients is unknown. We aimed to report ceiling of care and cardiopulmonary resuscitation (CPR) decisions and their association with demographic and clinical characteristics as well as outcomes during the COVID-19 pandemic. METHODS: Retrospective, observational study conducted between 5th March and 7th May 2020 of all hospitalised patients with COVID-19. Ceiling of care and CPR decisions were documented using the Recommended Summary Plan for Emergency Care and Treatment (ReSPECT) process. Unadjusted and multivariable regression analyses were used to determine factors associated with ceiling of care decisions and death during hospitalisation. RESULTS: A total of 485 patients were included, of whom 409 (84·3%) had a documented ceiling of care; level one for 208 (50·9%), level two for 75 (18·3%) and level three for 126 (30·8%). CPR decisions were documented for 451 (93·0%) of whom 336 (74·5%) were 'not for resuscitation'. Advanced age, frailty, White-European ethnicity, a diagnosis of any co-morbidity and receipt of cardiovascular medications were associated with ceiling of care decisions. In a multivariable model only advanced age (odds 0·89, 0·86-0·93 p < 0·001), frailty (odds 0·48, 0·38-0·60, p < 0·001) and the cumulative number of co-morbidities (odds 0·72, 0·52-1·0, p = 0·048) were independently associated. Death during hospitalisation was independently associated with age, frailty and requirement for level two or three care. CONCLUSION: Ceiling of care decisions were made for the majority of patients during the COVID-19 pandemic, broadly in line with known predictors of poor outcomes in COVID-19, but with a focus on co-morbidities suggesting ICU admission might not be a reliable end-point for observational studies where advanced care planning is routine.

A cohort study examining urgent and emergency treatment for decompensated severe aortic stenosis.

AIMS: We compared strategies in the treatment of decompensated severe aortic stenosis. The hypothesis was that undertaking urgent or emergency transcatheter aortic valve implantation (TAVI) directly in such patients is safer and more effective than urgent or emergency balloon aortic valvuloplasty (BAV) followed by elective TAVI or surgical aortic valve replacement (SAVR). METHODS: This was a single-centre retrospective study including all consecutive patients who underwent urgent or emergency BAV or TAVI for decompensated severe aortic stenosis between September 2014 and February 2018. Primary endpoints were 30-day and 1-year mortality. RESULTS: Fifty-two patients underwent urgent or emergency BAV and 87 underwent TAVI. Baseline characteristics of the two groups were well matched. Significant differences were noted between the two groups in 30-day all-cause mortality (88.5% BAV patients alive at 30 days, 97.7% TAVI patients; P < 0.05) and 1-year all-cause mortality (44.2% BAV patients alive at 1 year, 88.5% TAVI patients; P < 0.001). At 1 year, the estimated hazard ratio for patients undergoing BAV was 11.2 (95% confidence interval: 4.67-26.9; P < 0.001) when adjusted for potential confounding variables. Patients in the BAV group who successfully underwent subsequent TAVI or SAVR all survived for 365 days, but there was no significant 1-year mortality difference compared with those who underwent urgent or emergency TAVI (100 vs. 88.5%; P > 0.155). CONCLUSION: Our results suggest treatment of decompensated severe aortic stenosis with urgent or emergency TAVI may be associated with improved survival outcomes when compared with a strategy of performing BAV as a bridge to subsequent TAVI or SAVR.

Cardiac contractility modulation for the treatment of heart failure with reduced ejection fraction.

There has been a progressive evolution in the management of patients with chronic heart failure and reduced ejection fraction (HFrEF), including cardiac resynchronisation therapy (CRT) in those that fulfil pre-defined criteria. However, there exists a significant proportion with refractory symptoms in whom CRT devices are not clinically indicated or ineffective. Cardiac contractility modulation (CCM) is a novel therapy that incorporates administration of non-excitatory electrical impulses to the interventricular septum during the absolute refractory period. Implantation is analogous to a traditional transvenous pacemaker system, but with the use of two right ventricular leads. Mechanistic studies have shown augmentation of left ventricular contractility and beneficial global effects on reverse remodeling, primarily through alterations in calcium handling. This appears to occur without increasing myocardial oxygen consumption. Data from clinical trials have shown translational improvements in functional capacity and quality of life, though long-term outcome data are lacking. This review explores the rationale, evidence base and limitations of this nascent technology.

Sudden cardiac arrest of a 16-year-old boy with left main coronary artery atresia: a case report.

BACKGROUND: In many cases, the cause of exercise-induced cardiopulmonary arrest in young persons is thought to be fatal arrhythmia, and one of the causes is ischaemic heart disease. Left main coronary artery atresia (LMCAA) is an extremely rare disease in which there is a congenital defect of the left main coronary artery, causing heart failure and exercise-induced angina attacks at a young age. Thus, it is disease that should be differentiated when examining young persons with chest pain. CASE SUMMARY: A 16-year-old boy experienced sudden cardiopulmonary arrest during soccer practice, was brought to our hospital for emergency treatment after return of spontaneous circulation. Elective coronary angiography revealed findings indicating an osmium defect in the left coronary artery (LCA) and blood flow via collateral circulation from the right coronary artery. Contrast-enhanced coronary computed tomography (CT) angiography showed a defect in the LCA ostium and LMCAA was diagnosed in the patient. After coronary artery bypass grafting was performed, but the patient was discharged in an ambulatory state with a wearable cardiac defibrillator. Postoperative course has been favourable. DISCUSSION: Left main coronary artery atresia is an extremely rare disease in which there is a congenital defect of the left main trunk of the coronary artery and should be differentiated when encountering cases of heart failure or exercise-induced angina/arrhythmia attacks in young persons who are not at risk for atherosclerosis. Exercise electrocardiogram may show a false negative result, and therefore coronary CT is useful for diagnosis.

Long-term performance of left ventricular leads in cardiac resynchronisation therapy.

BACKGROUND: Cardiac resynchronisation therapy (CRT) confers symptomatic and survival benefits in chronic heart failure with reduced ejection fraction (HFrEF). There remains a paucity of data on long-term performance of left ventricular (LV) leads, particularly with newer quadripolar lead designs. METHODS: This single-centre study utilised an electronic, outpatient HFrEF database to identify CRT recipients (2008-2014). The primary endpoint was temporal trend in LV pacing thresholds during follow-up. Secondary outcomes were complications relating to acute or chronic lead failure and device-related infections. RESULTS: Two hundred eighty patients were included, with mean (±SD) age of 74.2 years (±9.0) and median follow-up of 7.6 years (interquartile range 4-9). Mean LV threshold was 1.37 V (±0.73) at implant and remained stable over the study period. No differences were observed based upon lead manufacturer. Compared to non-quadripolar leads (n = 216), those of quadripolar designs (n = 64) had a lower threshold at 6 months (1.20 vs 1.37 V; P = .04) and at the end of the study period (1.32 vs 1.46 V; P = .04). Patients with HFrEF of ischaemic aetiology had higher thresholds at implant (1.46 vs 1.34 V; P = .05), and this persisted until the end of follow-up (1.49 vs 1.34 V; P = .03). There was low incidence of acute (0.71%; 2/280) and chronic lead failure (1.79%; 5/280), with four cases (1.43%) of device infection. CONCLUSIONS: LV leads in the context of CRT have excellent chronic stability and low rates of adverse events. Those with newer quadripolar lead designs have lower thresholds at initial follow-up and in the longer term.

Assessment of coronary physiology - the evidence and implications.

Use of angiography for the assessment of coronary lesions is limited by its inability to provide information regarding the functional significance of stenoses. A number of studies have demonstrated the presence of ischaemia to be the most important determinant of the benefit associated with coronary revascularisation in stable coronary artery disease. Assessment of intra-coronary physiology can guide percutaneous coronary intervention, and is often used for angiographically borderline stenoses. There is now increasing evidence to suggest that more routine use can improve clinical outcomes. Fractional flow reserve (FFR) is the most established measure of intra-coronary physiology, but is currently under-utilised. The main drawback of FFR is the dependence on a pharmacological infusion to maintain hyperaemia. An alternative technique which measures flow at a specific point in the cardiac cycle (instantaneous wave-free ratio) has been developed which obviates the need for hyperaemia and may replace FFR as the default measure.

Leadless pacemakers - The path to safer pacing?

Endocardial transvenous permanent pacemakers (TVPs) are a mainstay within cardiology and used to treat a range of bradyarrhythmias. However, their use is associated with potential complications both at the time of implantation and longer term. The concept of a leadless pacemaker, where a self-contained device is placed within the right ventricle, has obvious attractions. Two leadless systems have been developed, though only one is currently available. Results from clinical trials have been promising but a number of hurdles need to be circumvented before leadless devices can usurp TVPs. At present, use is restricted to specialist centres, for a limited indication and for patients in whom conventional implantation is contraindicated. This article provides a contemporary critique of design types, evidence base and existing limitations of this nascent technology.

Prevalence and Predictors of Sepsis Death in Patients With Chronic Heart Failure and Reduced Left Ventricular Ejection Fraction.

Background Noncardiovascular death is increasingly common in people with chronic heart failure ( CHF ), yet its causes remain poorly characterized. We aimed to define the prevalence of sepsis death in people with CHF and to ascertain its risk marker profile. Methods and Results We conducted a prospective cohort study of 1802 patients with CHF and left ventricular ejection fraction ≤45% attending CHF clinics in 4 United Kingdom hospitals between 2006 and 2014. Mode of death was defined over a 10.3-year follow-up period (mean 4 years). Competing risk regression defined mode-specific hazard ratios for sepsis, other noncardiovascular, progressive heart failure, and sudden cardiac death in relation to established heart failure prognostic markers. Of 737 deaths, 173 (23.5%) were due to sepsis; respiratory tract infections accounted for 69.9% (n=121) of these events. Those who died from sepsis were older, had higher platelet counts, and had a higher prevalence of chronic obstructive pulmonary disease than those who died from other causes. Sepsis death was independently associated with older age (hazard ratio=1.05; 95% confidence interval 1.03-1.07), greater prevalence of chronic obstructive pulmonary disease (2.43; 1.74-3.40), male sex (1.73; 1.16-2.60), lower log serum vitamin D (0.68; 0.49-0.95), and higher platelet count (1.002; 1.000-1.005) than nonsepsis death. Established heart failure prognostic markers exhibited different patterns of association with sepsis death, other noncardiovascular death, progressive heart failure death, and sudden cardiac death. Conclusions Sepsis is a major contributor to death in people with CHF and has a different risk marker profile from other modes of death, suggesting that it may be amenable to targeted preventative strategies.

Ischemic Heart Disease Modifies the Association of Atrial Fibrillation With Mortality in Heart Failure With Reduced Ejection Fraction.

Background The CASTLE - AF (Catheter Ablation versus Standard Conventional Therapy in Patients With Left Ventricular Dysfunction and Atrial Fibrillation) trial recently reported that catheter ablation of atrial fibrillation ( AF ) improves survival in heart failure (HF) with reduced ejection fraction ( HF r EF ). However, established AF was not associated with mortality in trials of contemporary HF r EF pharmacotherapies. We investigated whether HF r EF pathogenesis may influence the conclusions of studies evaluating the prognostic impact of AF . Methods and Results Using a prospective cohort study of 791 patients with HFr EF , with AF determined using 24-hour ambulatory ECG monitoring, univariable and multivariable Cox regression analyses were used to define the association between AF and mode-specific mortality (mean follow-up of 5.4 years). One-year HF-related hospitalization was assessed with binary logistic regression analysis. One-year cardiac remodeling was assessed in a subgroup (n=378) using echocardiography. AF was present in 28.2% of patients, with 9.4% of these being paroxysmal. While AF was associated with increased risk of all-cause mortality (hazard ratio, 1.27; 95% confidence interval 1.03-1.57), with diverging survival curves after 1 year of follow-up, this association was lost in age-sex-adjusted analyses. However, AF was associated with increased risk of age-sex-adjusted all-cause mortality in people with ischemic pathogenesis, with a statistically significant interaction between pathogenesis and AF. This was predominantly attributed to progressive HF deaths. After 1 year, HF hospitalization and cardiac remodeling were not associated with AF , even in people with ischemic pathogenesis. Conclusions AF is associated with increased risk of death in HF r EF of ischemic pathogenesis, predominantly due to progressive HF deaths during long-term follow-up. HF r EF pathogenesis should be considered in trial design and interpretation.