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.     

Conduction system pacing in France in 2022: A snapshot survey from the Working Group of Pacing and Electrophysiology of the French Society of Cardiology

BackgroundConduction system pacing (CSP) is an emerging and promising approach for physiological ventricular pacing. While data from randomized controlled trials are scarce, use of His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP) has increased in France.AimTo perform a national snapshot survey for cardiac electrophysiologists to evaluate adoption of CSP in France.MethodsAn online survey, distributed to every senior cardiac electrophysiologist in France, was conducted in November 2022.ResultsA total of 120 electrophysiologists completed the survey. Eighty-three (69%) respondents reported experience in undertaking CSP procedures and 27 (23%) were planning to start performing CSP in the coming 2 years. The implantation techniques and criteria used for successful implantation differed significantly among operators. The most frequent indications for HBP and LBBAP were high-degree atrioventricular block with left ventricular ejection fraction (LVEF) < 40% (24 and 82%, respectively) or with LVEF ≥ 40% (27 and 74%, respectively), and after failure of a coronary sinus left ventricular lead (27 and 71%, respectively). The limitations respondents most frequently perceived when performing HBP were bad sensing/pacing parameters (45%), increased procedure duration (41%) and risk of lead dislodgement (30%). The most frequently perceived limitations to performing LBBAP were absence of guidelines or consensus (31%), lack of medical training (23%) and increased procedure duration (23%).ConclusionsOur national survey-based study supports wide adoption of CSP in France. CSP is currently used as a second-line approach for both antibradycardia and resynchronization indications, with important variations regarding implantation techniques and criteria for measuring success.     

Clinical course of arrhythmogenic right ventricular cardiomyopathy with end-stage heart failure and outcome after heart transplantation

BackgroundFew data exist on the characteristics and outcomes of patients with arrhythmogenic right ventricular cardiomyopathy and advanced heart failure who undergo heart transplantation.AimTo explore the pretransplant course and outcomes of patients with arrhythmogenic right ventricular cardiomyopathy after heart transplantation.MethodsThis observational retrospective monocentric study included all consecutive patients with arrhythmogenic right ventricular cardiomyopathy who underwent heart transplantation during a 13-year period (2006–2019) at Pitié-Salpêtrière University Hospital (Paris).ResultsA total of 23 patients with arrhythmogenic right ventricular cardiomyopathy underwent heart transplantation between 2006 and 2019. The median time from diagnosis to heart transplantation was 9 years, and the median age at transplantation was 50 years. At diagnosis, half of the patients had left ventricular dysfunction, 59% had extensive T-wave inversion and 43% had a history of sustained ventricular tachycardia. Only five patients were involved in intensive sport activity. Indications for heart transplantation were end-stage biventricular dysfunction in 13 patients, end-stage right ventricular heart failure in seven and electrical storm in three. Only three patients had pulmonary hypertension, and half of the patients had atrial arrhythmias. The survival rate 1 year after heart transplantation was 74% (95% confidence interval 53–88%). Eight patients experienced primary graft dysfunction needing extracorporeal membrane oxygenation.ConclusionsPatients with arrhythmogenic right ventricular cardiomyopathy who eventually needed heart transplantation mostly exhibited extended disease with biventricular dysfunction at diagnosis. Intensive sport activity did not seem to be a major determinant. Advanced heart failure usually occurred late in the course of the disease. Primary graft dysfunction after heart transplantation was frequent, and should be anticipated. Additional data are needed to identify the optimal timing for heart transplantation and predictors of end-stage heart failure in patients with arrhythmogenic right ventricular cardiomyopathy.     

Unsupervised clustering of patients with severe aortic stenosis: A myocardial continuum

BackgroundTraditional statistics, based on prediction models with a limited number of prespecified variables, are probably not adequate to provide an appropriate classification of a condition that is as heterogeneous as aortic stenosis (AS).AimsTo investigate a new classification system for severe AS using phenomapping.MethodsConsecutive patients from a referral centre (training cohort) who met the echocardiographic definition of an aortic valve area (AVA) ≤ 1 cm² were included. Clinical, laboratory and imaging continuous variables were entered into an agglomerative hierarchical clustering model to separate patients into phenogroups. Individuals from an external validation cohort were then assigned to these original clusters using the K nearest neighbour (KNN) function and their 5-year survival was compared after adjustment for aortic valve replacement (AVR) as a time-dependent covariable.ResultsIn total, 613 patients were initially recruited, with a mean ± standard deviation AVA of 0.72 ± 0.17 cm². Twenty-six variables were entered into the model to generate a specific heatmap. Penalized model-based clustering identified four phenogroups (A, B, C and D), of which phenogroups B and D tended to include smaller, older women and larger, older men, respectively. The application of supervised algorithms to the validation cohort (n = 1303) yielded the same clusters, showing incremental cardiac remodelling from phenogroup A to phenogroup D. According to this myocardial continuum, there was a stepwise increase in overall mortality (adjusted hazard ratio for phenogroup D vs A 2.18, 95% confidence interval 1.46–3.26; P < 0.001).ConclusionsArtificial intelligence re-emphasizes the significance of cardiac remodelling in the prognosis of patients with severe AS and highlights AS not only as an isolated valvular condition, but also a global disease.     

AI Based CMR Assessment of Biventricular Function: Clinical Significance of Intervendor Variability and Measurement Errors

ObjectivesThe aim of this study was to determine whether left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) and left ventricular mass (LVM) measurements made using 3 fully automated deep learning (DL) algorithms are accurate and interchangeable and can be used to classify ventricular function and risk-stratify patients as accurately as an expert.BackgroundArtificial intelligence is increasingly used to assess cardiac function and LVM from cardiac magnetic resonance images.MethodsTwo hundred patients were identified from a registry of individuals who underwent vasodilator stress cardiac magnetic resonance. LVEF, LVM, and RVEF were determined using 3 fully automated commercial DL algorithms and by a clinical expert (CLIN) using conventional methodology. Additionally, LVEF values were classified according to clinically important ranges: <35%, 35% to 50%, and ≥50%. Both ejection fraction values and classifications made by the DL ejection fraction approaches were compared against CLIN ejection fraction reference. Receiver-operating characteristic curve analysis was performed to evaluate the ability of CLIN and each of the DL classifications to predict major adverse cardiovascular events.ResultsExcellent correlations were seen for each DL-LVEF compared with CLIN-LVEF (r = 0.83-0.93). Good correlations were present between DL-LVM and CLIN-LVM (r = 0.75-0.85). Modest correlations were observed between DL-RVEF and CLIN-RVEF (r = 0.59-0.68). A >10% error between CLIN and DL ejection fraction was present in 5% to 18% of cases for the left ventricle and 23% to 43% for the right ventricle. LVEF classification agreed with CLIN-LVEF classification in 86%, 80%, and 85% cases for the 3 DL-LVEF approaches. There were no differences among the 4 approaches in associations with major adverse cardiovascular events for LVEF, LVM, and RVEF.ConclusionsThis study revealed good agreement between automated and expert-derived LVEF and similarly strong associations with outcomes, compared with an expert. However, the ability of these automated measurements to accurately classify left ventricular function for treatment decision remains limited. DL-LVM showed good agreement with CLIN-LVM. DL-RVEF approaches need further refinements.     

Association between epicardial adipose tissue and left ventricular function in type 2 diabetes mellitus: Assessment using two-dimensional speckle tracking echocardiography

Background and aimsEpicardial adipose tissue (EAT) is the visceral fat between the myocardium and the visceral pericardium. Dysfunctional EAT can cause cardiovascular diseases. The aim of this study was to investigate the association between EAT and left ventricular function in type 2 diabetes mellitus (T2DM) patients by two-dimensional speckle tracking echocardiography (2D-STE).MethodsWe prospectively enrolled 116 T2DM patients who were divided into two groups according to their left ventricular global longitudinal strain (GLS): 53 with GLS <18% and 63 with GLS ≥18%. The thickness of EAT was measured as the echo-free space between the free wall of the right ventricle and the visceral layer of pericardium at end-systole. LV systolic function was evaluated by GLS measured by 2D-STE. LV diastolic function was defined as the ratio of the early diastolic transmitral flow velocity (E) to average mitral annular velocity ($\overline{e}$).ResultsCompared with patients with GLS ≥18% group, the age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-C), glycosylated hemoglobinA1c (HbA1c), E/$\overline{e}$, and thickness of EAT were higher in patients with GLS <18% group (all P < 0.05). Multivariate linear regression analysis revealed that the thickness of EAT was independently associated with left ventricular GLS and E/$\overline{e}$.ConclusionsThickened EAT is associated with impaired left ventricular function in T2DM patients. To investigate the association between EAT and left ventricular function can help us gain a deeper understanding of the pathogenesis of impaired cardiac function in T2DM patients.     

Strain echocardiography in predicting LV dysfunction in RV apical pacing

Right ventricular (RV) pacing is associated with a reduction in left ventricular (LV) systolic function, thought to be mediated by pacing-induced ventricular dyssynchrony. The prevalence of heart failure after RV pacing is reported to range from 31±3%. We studied 60 subjects with high-grade atrioventricular block and Complete Heart Block (CHB) scheduled to undergo right ventricular apical pacing. 2D echocardiography was done at baseline, 1 month and 12 months. Pacing-induced cardiomyopathy was defined as a reduction in LVEF to <45%. Strain was evaluated off-line from digitally stored images using all advanced software package (cardiac wall motion quantification (CMQ); Toshiba Medical Systems). Longitudinal strain for individual myocardial segments was measured from the apical four-chamber, two-chamber and long axis views (16 segment AHA/ASE model). None had LV dysfunction at baseline based on 2D and strain echo imaging. Subsequently 18 patients were detected to develop low GLS score (less than -14.5) at 1 month. On subsequent follow up at 1 year, all 18 patients developed LV dysfunction on 2D Echocardiography. Thus Strain imaging with GLS score helped in early detection of LV dysfunction in RV apical pacing subjects. Pacing-induced cardiomyopathy had significant association with high grade AV block with pacemaker dependency. It had no significant associations with other comorbidities like diabetes, hypertension, ischemic heart disease or with the type of medication intake. However there was a statistically significant association with heart failure.     

Prevalence of liver fibrosis in an unselected general population with high prevalence of obesity and diabetes mellitus. Time for screening?

IntroductionCirrhosis and liver cancer are currently common causes of death worldwide. The global epidemic of obesity has increased the incidence of nonalcoholic fatty liver disease (NAFLD) and cirrhosis in recent years. Advanced fibrosis increases the morbimortality rate in NAFLD. The Mexican population has one of the highest prevalence of obesity and diabetes mellitus (DM) worldwide.AimTo determine the prevalence of advanced liver fibrosis in Mexican general population.MethodsAdult individuals, without a history of liver disease nor heavy alcohol consumption were randomly sampled from 20,919 participants of a health and nutrition survey applied to the general population. Clinical and laboratory evaluations were performed to calculate the NAFLD fibrosis score (NFS) (an extensively validated non-invasive method). Two cut-off points were used. Advanced fibrosis was defined as a result >0.676.ResultsIn total 695 individuals were included. The mean age was 47.8 ± 16.4. The majority were between 20 and 50 years (59%), 70.2% were female, 35.5% showed obesity and 15.8% DM. The 93% had normal serum ALT. Based on the NFS results, 56 individuals (8.1%) had a high probability of fibrosis. Most patients from this subgroup showed normal serum ALT (92.9%), 89.3% were >45 yr. old, 52% were obese and 27% suffered from DM.ConclusionsBased on these results, 8.1% of Mexican general population without a history of liver disease is at high risk of having advanced liver fibrosis and complications and death derived from cardiovascular disease and cirrhosis. Most of them showed normal ALT serum levels.     

Associations of serum magnesium levels and calcium–magnesium ratios with mortality in patients with coronary artery disease

AimsLow magnesium (Mg) and high calcium (Ca) levels are linked to increased cardiovascular disease (CVD) risk in the general population. This prospective study assessed whether there are any independent associations of serum Mg levels and Ca–Mg ratios with mortality in patients with coronary artery disease (CAD).MethodsThis prospective cohort study included 3380 CAD patients. Cox regression models were used to estimate associations of serum Mg and Ca–Mg ratio with risk of mortality.ResultsA total of 562 deaths (331 due to CVD) were recorded during a 7.59-year (median) follow-up. Spline plots displayed U-shaped associations between serum Mg levels and Ca–Mg ratios and risk of mortality. When compared with a moderate group, adjusted hazard ratios (95% confidence intervals) for low Mg levels and high Ca–Mg ratios were 1.59 (1.30–1.95) and 1.31 (1.06–1.61) for all-cause mortality, and 1.71 (1.32–2.22) and 1.44 (1.09–1.89) for CVD mortality, respectively. There was also a tendency to increase risk of mortality in patients with high serum Mg levels and low Ca–Mg ratios. Associations of low serum Mg and high Ca–Mg ratio with risk of mortality did not change when stratified by gender, body mass index, CAD type, estimated glomerular filtration rate, use of diuretics, or history of diabetes or hypertension.ConclusionThis study demonstrated that a moderate Ca–Mg ratio (range: 3.91–4.70) had the lowest mortality risk, and that low serum Mg and high Ca–Mg ratio were independent risk factors of mortality in CAD patients. Nevertheless, the optimal dose–response of Mg and Ca for mitigating CAD risk still requires further investigation.     

Comparative effectiveness of devices for transcatheter closure of atrial septal defects: Systematic review and network meta-analysis

Atrial septal defect is a common congenital heart disease, producing a left-to-right shunt in the atrial septum; the current preferred treatment is transcatheter device closure. The aim is to conduct a systematic review to synthesize information on the comparative effectiveness and safety of atrial septal defect closure devices. The methods used: a comprehensive search of Ovid MEDLINE®, Embase, and Cochrane Central databases was conducted. Studies comparing procedural and follow-up outcomes of atrial septal defect devices were included. Network meta-analyses were conducted to generate direct and indirect evidence for comparative effectiveness and safety outcomes between devices. The results are as follows: Twelve studies met our inclusion criteria and were compared in network meta-analyses. The meta-analyses evaluated contemporary devices: the AMPLATZER Septal Occluder; the GORE CARDIOFORM Septal Occluder; the Figulla Flexible II Occluder; the CeraFlex Septal Occluder; and the HELEX Septal Occluder. These studies represented 3998 patients. The primary safety and efficacy outcomes were device embolization and follow-up residual shunt, respectively. Secondary clinical outcomes included procedural success and major and minor complications. No differences were found between devices in terms of device embolization and secondary clinical outcomes. Follow-up residual shunt was higher with the HELEX Septal Occluder compared with the AMPLATZER Septal Occluder (odds ratio 2.92, 95% confidence interval 1.12–7.61). To conclude: although most outcomes were similar between devices, evidence was largely based on observational low-quality studies. There were inconsistencies in outcome reporting and definitions; this merits future studies, with head-to-head device comparisons and standardization of outcomes.     

Higher liver stiffness scores are associated with early kidney dysfunction in patients with histologically proven non-cirrhotic NAFLD

AimThe association between Liver fibrosis (LF), as assessed by either histology or Liver stiffness measurement (LSM), and the presence of Early kidney dysfunction (EKD) was investigated in this study, as was also the diagnostic performance of LSM for identifying the presence of EKD in patients with Non-alcoholic fatty liver disease (NAFLD).Materials and methodsA total of 214 adults with non-cirrhotic biopsy-proven NAFLD were recruited from two independent medical centres. Their histological stage of LF was quantified using Brunt's criteria. Vibration-controlled Transient elastography (TE), using M-probe (FibroScan®) ultrasound, was performed in 154 patients and defined as significant when LSM was ≥ 8.0 kPa. EKD was defined as the presence of microalbuminuria with an estimated glomerular filtration rate ≥ 60 mL/min/1.73 m². Logistic regression modelling was used to estimate the likelihood of having EKD with NAFLD (LSM–EKD model).ResultsThe prevalence of EKD was higher in patients with vs without LF on histology (22.14% vs 4.82%, respectively; P < 0.001) and, similarly, EKD prevalence was higher in patients with LSM ≥ 8.0 kPa vs LSM < 8.0 kPa (23.81% vs 6.59%, respectively; P < 0.05). The area under the ROC curve of the LSM–EKD model for identifying EKD was 0.80 (95% CI: 0.72–0.89). LF detected by either method was associated with EKD independently of established renal risk factors and potential confounders.ConclusionLF was independently associated with EKD in patients with biopsy-proven NAFLD. Thus, TE-measured LSM, a widely used technique for quantifying LF, can accurately identify those patients with NAFLD who are at risk of having EKD.