Blood groups and Rhesus status as potential predictors of outcomes in patients with cardiac resynchronisation therapy.

Cardiac resynchronisation therapy (CRT) improves prognosis in patients with heart failure (HF) however the role of ABO blood groups and Rhesus factor are poorly understood. We hypothesise that blood groups may influence clinical and survival outcomes in HF patients undergoing CRT. A total of 499 patients with HF who fulfilled the criteria for CRT implantation were included. Primary outcome of all-cause mortality and/or heart transplant/left ventricular assist device was assessed over a median follow-up of 4.6 years (IQR 2.3-7.5). Online repositories were searched to provide biological context to the identified associations. Patients were divided into blood (O, A, B, and AB) and Rhesus factor (Rh-positive and Rh-negative) groups. Mean patient age was 66.4 ± 12.8 years with a left ventricular ejection fraction of 29 ± 11%. There were no baseline differences in age, gender, and cardioprotective medication. In a Cox proportional hazard multivariate model, only Rh-negative blood group was associated with a significant survival benefit (HR 0.68 [0.47-0.98], p = 0.040). No association was observed for the ABO blood group (HR 0.97 [0.76-1.23], p = 0.778). No significant interaction was observed with prevention, disease aetiology, and presence of defibrillator. Rhesus-related genes were associated with erythrocyte and platelet function, and cholesterol and glycated haemoglobin levels. Four drugs under development targeting RHD were identified (Rozrolimupab, Roledumab, Atorolimumab, and Morolimumab). Rhesus blood type was associated with better survival in HF patients with CRT. Further research into Rhesus-associated pathways and related drugs, namely whether there is a cardiac signal, is required.

The BLISTER Score: A Novel, Externally Validated Tool for Predicting Cardiac Implantable Electronic Device Infections, and Its Cost-Utility Implications for Antimicrobial Envelope Use.

BACKGROUND: Antimicrobial envelopes reduce the incidence of cardiac implantable electronic device infections, but their cost restricts routine use in the United Kingdom. Risk scoring could help to identify which patients would most benefit from this technology. METHODS: A novel risk score (BLISTER [Blood results, Long procedure time, Immunosuppressed, Sixty years old (or younger), Type of procedure, Early re-intervention, Repeat procedure]) was derived from multivariate analysis of factors associated with cardiac implantable electronic device infection. Diagnostic utility was assessed against the existing PADIT score (Prior procedure, Age, Depressed renal function, Immunocompromised, Type of procedure) in both standard and high-risk external validation cohorts, and cost-utility models examined different BLISTER and PADIT score thresholds for TYRX (Medtronic; Minneapolis, MN) antimicrobial envelope allocation. RESULTS: In a derivation cohort (n=7383), cardiac implantable electronic device infection occurred in 59 individuals within 12 months of a procedure (event rate, 0.8%). In addition to the PADIT score constituents, lead extraction (hazard ratio, 3.3 [95% CI, 1.9-6.1]; P<0.0001), C-reactive protein >50 mg/L (hazard ratio, 3.0 [95% CI, 1.4-6.4]; P=0.005), reintervention within 2 years (hazard ratio, 10.1 [95% CI, 5.6-17.9]; P<0.0001), and top-quartile procedure duration (hazard ratio, 2.6 [95% CI, 1.6-4.1]; P=0.001) were independent predictors of infection. The BLISTER score demonstrated superior discriminative performance versus PADIT in the standard risk (n=2854, event rate: 0.8%, area under the curve, 0.82 versus 0.71; P=0.001) and high-risk validation cohorts (n=1961, event rate: 2.0%, area under the curve, 0.77 versus 0.69; P=0.001), and in all patients (n=12 198, event rate: 1%, area under the curve, 0.8 versus 0.75, P=0.002). In decision-analytic modeling, the optimum scenario assigned antimicrobial envelopes to patients with BLISTER scores ≥6 (10.8%), delivering a significant reduction in infections (relative risk reduction, 30%; P=0.036) within the National Institute for Health and Care Excellence cost-utility thresholds (incremental cost-effectiveness ratio, £18 446). CONCLUSIONS: The BLISTER score (https://qxmd.com/calculate/calculator_876/the-blister-score-for-cied-infection) was a valid predictor of cardiac implantable electronic device infection, and could facilitate cost-effective antimicrobial envelope allocation to high-risk patients.

DOACs vs Vitamin K Antagonists During Cardiac Rhythm Device Surgery: A Multicenter Propensity-Matched Study.

BACKGROUND: There is a paucity of data comparing vitamin K antagonists (VKAs) to direct oral anticoagulants (DOACs) at the time of cardiac implantable electronic device (CIED) surgery. Furthermore, the best management of DOACs (interruption vs continuation) is yet to be determined. OBJECTIVES: This study aimed to compare the incidence of device-related bleeds and thrombotic events based on anticoagulant type (DOAC vs VKA) and regimen (interrupted vs uninterrupted). METHODS: This was an observational multicenter study. We included patients on chronic oral anticoagulation undergoing CIED surgery. Patients were matched using propensity scoring. RESULTS: We included 1,975 patients (age 73.8 ± 12.4 years). Among 1,326 patients on DOAC, this was interrupted presurgery in 78.2% (n = 1,039) and continued in 21.8% (n = 287). There were 649 patients on continued VKA. The matched population included 861 patients. The rate of any major bleeding was higher with continued DOAC (5.2%) compared to interrupted DOAC (1.7%) and continued VKA (2.1%) (P = 0.03). The rate of perioperative thromboembolism was 1.4% with interrupted DOAC, whereas no thromboembolic events occurred with DOAC or VKA continuation (P = 0.04). The use of dual antiplatelet therapy, DOAC continuation, and male sex were independent predictors of major bleeding on a multivariable analysis. CONCLUSIONS: In this large real-world cohort, a continued DOAC strategy was associated with a higher bleeding risk compared to DOAC interruption or VKA continuation in patients undergoing CIED surgery. However, DOAC interruption was associated with increased thromboembolic risk. Concomitant dual antiplatelet therapy should be avoided whenever clinically possible. A bespoke approach is necessary, with a strategy of minimal DOAC interruption likely to represent the best compromise.

Feasibility of double-blinded, placebo-controlled interventional study for assessing catheter ablation efficacy in persistent atrial fibrillation: Insights from the ORBITA AF feasibility study.

BACKGROUND: To date, there are no randomized, double-blinded clinical trials comparing catheter ablation to DC cardioversion (DCCV) with medical therapy in patients with persistent atrial fibrillation (PersAF). Conducting a large-scale trial to address this question presents considerable challenges, including recruitment, blinding, and implementation. We conducted a pilot study to evaluate the feasibility of conducting a definitive placebo-controlled trial. METHODS: This prospective trial was carried out at Barts Heart Centre, United Kingdom, employing a randomized, double-blinded, placebo-controlled design. Twenty patients with PersAF (duration <2 years) were recruited, representing 10% of the proposed larger trial as determined by a power calculation. The patients were randomized in a 1:1 ratio to receive either PVI ± DCCV (PVI group) or DCCV + Placebo (DCCV group). The primary endpoint of this feasibility study was to evaluate patient blinding. Patients remained unaware of their treatment allocation until end of study. RESULTS: During the study, 35% of patients experienced recurrence of PersAF prior to completion of 12 months follow-up. Blinding was successfully maintained amongst both patients and medical staff. The DCCV group had a trend to higher recurrence and repeat procedure rate compared to the PVI group (recurrence of PersAF 60% vs 30%; p = .07 and repeat procedure 70% vs 40%; p = .4). The quality of life experienced by individuals in the PVI group showed improvement, as evidenced by enhanced scores on the AF specific questionnaire (AF PROMS) (3 [±4] vs 21 [±8]) and SF-12 mental-component raw score (51.4 [±7] vs 43.24 [±15]) in patients who maintained sinus rhythm at 12 months. CONCLUSION: This feasibility study establishes the potential for conducting a blinded, placebo-controlled trial to evaluate the efficacy of PVI versus DCCV in patients with PersAF.

Amplified sinus-P-wave analysis predicts outcomes of cryoballoon ablation in patients with persistent and long-standing persistent atrial fibrillation: A multicentre study.

Introduction: Outcomes of catheter ablation for non-paroxysmal atrial fibrillation (AF) remain suboptimal. Non-invasive stratification of patients based on the presence of atrial cardiomyopathy (ACM) could allow to identify the best responders to pulmonary vein isolation (PVI). Methods: Observational multicentre retrospective study in patients undergoing cryoballoon-PVI for non-paroxysmal AF. The duration of amplified P-wave (APW) was measured from a digitally recorded 12-lead electrocardiogram during the procedure. If patients were in AF, direct-current cardioversion was performed to allow APW measurement in sinus rhythm. An APW cut-off of 150 ms was used to identify patients with significant ACM. We assessed freedom from arrhythmia recurrence at long-term follow-up in patients with APW ≥ 150 ms vs. APW < 150 ms. Results: We included 295 patients (mean age 62.3 ± 10.6), of whom 193 (65.4%) suffered from persistent AF and the remaining 102 (34.6%) from long-standing persistent AF. One-hundred-forty-two patients (50.2%) experienced arrhythmia recurrence during a mean follow-up of 793 ± 604 days. Patients with APW ≥ 150 ms had a significantly higher recurrence rate post ablation compared to those with APW < 150 ms (57.0% vs. 41.6%; log-rank p < 0.001). On a multivariable Cox-regression analysis, APW≥150 ms was the only independent predictor of arrhythmia recurrence post ablation (HR 2.03 CI95% 1.28-3.21; p = 0.002). Conclusion: APW duration predicts arrhythmia recurrence post cryoballoon-PVI in persistent and long-standing persistent AF. An APW cut-off of 150 ms allows to identify patients with significant ACM who have worse outcomes post PVI. Analysis of APW represents an easy, non-invasive and highly reproducible diagnostic tool which allows to identify patients who are the most likely to benefit from PVI-only approach.

Exploiting SMART pass filter deactivation detection to minimize inappropriate subcutaneous implantable cardioverter defibrillator therapies: a real-world single-centre experience and management guide.

AIMS: The SMART Pass™ (SP) algorithm is a high-pass filter that aims to reduce inappropriate therapy (IT) in subcutaneous internal cardiac defibrillator (S-ICD), but SP can deactivate due to low amplitude sensed R waves or asystole. The association between IT and SP deactivation and management strategies were evaluated, hypothesizing SP deactivation increases the risk of IT and device re-programming, or lead/generator re-positioning could reduce this risk. METHODS AND RESULTS: Retrospective single-centre audit of Emblem™ S-ICD devices implanted 2016 to 2020 utilizing health records and remote monitoring data. Cox regression models evaluated associations between SP deactivation and IT. A total of 348 patients (27 ± 16.6 months follow-up) were studied: 73% primary prevention. Thirty-eight patients (11.8%) received 83 shocks with 27 patients (7.8%) receiving a total of 44 IT. Causes of IT were oversensing (98%) and aberrantly conducted atrial fibrillation (2%). SP deactivation occurred in 32 of 348 patients (9%) and was significantly associated with increased risk of IT (hazard ratio 5.36, 95% CI 2.37-12.13). SP deactivation was due to low amplitude R waves (94%), associated with a higher defibrillation threshold at implant and presence of arrhythmogenic right ventricular cardiomyopathy. No further IT occurred 16 ± 15.5 months after corrective interventions, with changing the sensing vector being successful in 59% of cases. CONCLUSION: To reduce the risk of IT, the cause of the SP deactivation should be investigated, and appropriate reprogramming, device, or lead modifications made. Utilizing the alert for SP deactivation and electrograms could pro-actively prevent IT.

Impact of Endothelial Dysfunction on Long-Term Clinical Outcomes in Patients With Chronic Coronary Syndromes Treated With Second Generation Drug-Eluting Stent Implantation.

BACKGROUND: Studies investigating clinical outcomes of patients with or without endothelial disfunction (ED) treated with percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD) using second generation drug eluting stents (DES) are lacking. METHODS: We prospectively collected data from 109 patients undergoing PCI with second generation DES due to stable CAD between December 2014 and September 2016. ED was evaluated evaluating the flow mediated dilation (FMD) at the brachial artery level and defined by an FMD < 7 %. Primary outcome were major adverse cardiovascular events (MACE), secondary outcomes were target vessel failure (TVR), myocardial infarction (MI) and all-cause death. RESULTS: Five-year follow-up was available in all patients. Median FMD didn't significantly differ between patients who experienced the outcome and those who didn't [no TVR vs. TVR: p = 0.358; no MI vs. MI: p = 0.157; no death vs. death: p = 0.355; no MACE vs. MACE: p = 0.805]. No association between ED and an increased risk for the primary outcome as well as for the secondary ones was evident [MACE: 17.0 % vs. 14.3 %, HR 0.87 (0.33-2.26), log rank p = 0.780; TVR: 9.4 % vs. 5.4 %, HR 0.53 (0.12-2.24), log rank p = 0.384; MI: 3.7 % vs. 8.9 %, HR 2.46 (0.47-12.76), log rank p = 0.265; death: 7.5 % vs. 3.6 %, HR 0.53 (0.09-2.90), log rank p = 0.458]. These findings were confirmed using a lower threshold of FMD to define ED and at one-year landmark analysis. CONCLUSIONS: ED is not associated with an increased risk of adverse events at long-term follow-up in a contemporary cohort of patients undergoing PCI with second generation DES.

Catheter ablation of atrial fibrillation with a multi-electrode radiofrequency balloon; first and early two centre experience in Europe.

INTRODUCTION: The Heliostar™ ablation system is a novel RF balloon ablation technology with an integrated three-dimensional mapping system. Here, we describe our early experience and procedural outcomes using this technology for atrial fibrillation catheter ablation. METHODS: We sought to comprehensively assess the first 60 consecutive patients undergoing pulmonary vein isolation using the novel HELISOTAR™ RF balloon technology including procedural outcomes. A comparison of the workflow between two different anaesthetic modalities (conscious sedation [CS] vs. general anaesthesia [GA]) was made. Procedural data were collected prospectively from two high-volume centers (Barts Heart Centre, UK and University Hospital of Zurich, Zurich). A standardized approach for catheter ablation was employed. RESULTS: A total of 35 patients had the procedure under CS and the remaining under GA. Mean procedural and fluoroscopy times were 84 ± 33 min and 1.1 min. The median duration of RF energy application was 7 (5-9.8) mins per patient. All veins were successfully isolated, and the median isolation time was 10 (7-15) seconds. Our cohort's rate of procedural complications was low, with no mortality within 30 days postprocedure. CONCLUSION: Our early experience shows that catheter ablation using the Heliostar™ technology can be performed efficiently and safely; however, long-term data is yet to be established. Low fluoroscopy requirements, short learning curves and use of this technology with CS is possible, including the use of an oesophageal temperature probe.

Influence of gender and malnutrition on QT dispersion in a north-Malagasy children population.

BACKGROUND: Children malnutrition involves simultaneous deficiency of nutrients, leading to cardiac morphological and functional alterations. In this complex condition repolarization abnormalities can evolve. Also, sexual dimorphism is a well-established phenomenon, but its influence on ventricular repolarization varies tremendously among races. No data are available about African children, so the aim of our work was to study the correlation between malnourishment and electrocardiographic repolarization parameters and evaluating the sex influence. METHODS: Three hundred seven children (mean age 7.6±3 years old) were consecutively enrolled in the north of Madagascar. The QT interval was measured and corrected (QTc) following the Bazett formula (QT/√RR). QT dispersion (QTcd) was defined as the difference between maximum and minimum QTc. Malnutrition was defined in relation to age and sex specific BMI values. Grade mild, moderate and severe were defined as the value to pass through BMI of 16, 17 and 18.5 at the age of 18. RESULTS: One hundred twenty-six children (41%) were malnourished, 42 (13%) with mild, 61 (20%) moderate and 23 (7%) with a severe grade. No differences were found between normal weight and malnourished regarding the gender, age, height, or heart rate. They had similar QT and QTc intervals (respectively 362.4±36 ms vs. 365.1±47 ms for QT, P=0.59 and 476.9±43 ms vs. 470±53 ms for QTc, P=0.70). QTcd was statistically higher in malnourished children (53.2±16 ms vs. 44.4±15 ms, P<0.001). QTcd progressively increased from normal weight to severe malnutrition (P<0.001). At multivariate analysis, independently from sex category, children with moderate (C.I. 3.94-13.1, P<0.001) and severe (C.I. 8.38-22.0, P<0.001) malnutrition had a higher risk to have a higher QTcd). 146 children (48%) were male. Prolonged QTcd was found more frequently in male children (58% vs. 44%, P=0.04), showing also longer QTc and QTcd (respectively 475.8±52 ms vs. 462.3±42 ms, P=0.01; and 50.1±16 ms vs. 46.2±16 ms, P=0.03). At the multivariate analysis, males had a higher risk (C.I. 0.28-7.35, P=0.03) to have higher QTc dispersion with respect to female children, independently to the nutrition state. CONCLUSIONS: Moderate to severe malnourishment and male sex independently influence ventricular repolarization, with higher QTc dispersion times and eventually higher risk of future arrhythmic complications. In these children, precaution must be taken with intensive correction of malnutrition and a strict ECG follow-up.

Defining electrocardiographic criteria to differentiate non-type 1 Brugada ECG variants from normal incomplete RBBB patterns in the young SCD-SOS cohort.

INTRODUCTION: We assessed the prevalence of non-type 1 Brugada pattern (T1BrP) in children and young adults from the Sudden Cardiac Death-Screening Of risk factorS cohort and the diagnostic yield of nonexpert manual and automatic algorithm electrocardiogram (ECG) measurements. METHODS: Cross-sectional study. We reviewed 14 662 ECGs and identified 2226 with a rSr'-pattern in V1-V2. Among these, 115 were classified by experts in hereditary arrhythmic-syndromes as having or not non-T1BrP, and were compared with measurements of 5 ECG-derived parameters based on a triangle formed by r' -wave (d(A), d(B), d(B)/h, ß-angle) and ST-ascent, assessed both automatically and manually by nonexperts. We estimated intra- and interobserver concordance for each criterion, calculated diagnostic accuracy and defined the most appropriate cut-off values. RESULTS: A rSr'-pattern in V1-V2 was associated with higher PQ interval and QRS duration, male gender, and lower body mass index (BMI). The manual measurements of non-T1BrP criteria were moderately reproducible with high intraobserver and moderate interobserver concordance coefficients (ICC: 0.72-0.98, and 0.63-0.76). Criteria with higher discriminatory capacity were: distance d(B) (0.72; 95% confidence interval [CI]: 0.65-0.80) and ST-ascent (0.87; 95% CI: 0.82-0.92), which was superior to the 4 r'-wave criteria together (area under curve [AUC: 0.74]). We suggest new cut-offs with improved combination of sensitivity and specificity: d(B) ≥ 1.4 mm and ST-ascent ≥ 0.7 mm (sensitivity: 1%-82%; specificity: 71%-84%), that can be automatically measured to allow classification in four morphologies with increasing non-T1BrP probability. CONCLUSION: rSr'-pattern in precordial leads V1-V2 is a frequent finding and the detection of non-T1BrP by using the aforementioned five measurements is reproducible and accurate. In this study, we describe new cut-off values that may help untrained clinicians to identify young individuals who may require further work-up for a potential Brugada Syndrome diagnosis.

PolarX Cryoballoon metrics predicting successful pulmonary vein isolation: targets for ablation of atrial fibrillation.

AIM: Evaluate the novel PolarX Cryoballoon in atrial fibrillation (AF) catheter ablation through a propensity-matched comparison with the Arctic Front Advance (AFA). The aim was also to identify cryoablation metrics that are predictive of successful pulmonary vein isolation (PVI) with the PolarX Cryoballoon. METHODS AND RESULTS: This prospective multi-centre study included patients that underwent cryoablation for AF. All patients underwent PVI with reconnection assessed after a 30-min waiting period and adenosine. Safety, efficacy, and cryoablation metrics were compared between PolarX and a propensity-matched AFA cohort. Seventy patients were included with 278 veins treated. In total, 359 cryoablations were performed (1.3 ± 0.6 per vein) to achieve initial PVI with 205 (73.7%) veins isolating with a single cryoablation. Independent predictors for achieving initial PVI included temperature at 30 s [odds ratio (OR) 1.26; P = 0.003] and time to reach -40°C (OR 1.88; P < 0.001) with an optimal cut-off of ≤-38.5°C at 30 s [area under the curve (AUC) 0.79; P < 0.001] and ≤-40°C at ≤32.5 s (AUC 0.77; P < 0.001), respectively. Of the 278 veins, 46 (16.5%) veins showed acute reconnection. Temperature at 30 s (≤-39.5°C, OR 1.24; P = 0.002), nadir temperature (≤-53.5°C, OR 1.35; P = 0.003), and time to isolation (≤38.0 s, OR 1.18; P = 0.009) were independent predictors of sustained PVI. Combining two of these three targets was associated with reconnection in only 2-5% of PVs. Efficacy and safety of the PolarX Cryoballoon were comparable to AFA Cryoballoon, however, cryoablation metrics were significantly different. CONCLUSIONS: The PolarX Cryoballoon has a different cryoablation profile to AFA Cryoballoon. Prospective testing of these proposed targets in large outcomes studies is required.

Transseptal puncture for left atrial ablation: Risk factors for cardiac tamponade and a proposed causative classification system.

AIMS: Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP). We examined the associations of TSP-related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our center from 2016 to 2020. METHODS AND RESULTS: Patient and procedural variables were extracted retrospectively. Cases of cardiac tamponade were scrutinized to adjudicate TSP culpability. Adjusted multivariate analysis examined predictors of TRCT. A total of 3239 consecutive TSPs were performed; cardiac tamponade occurred in 51 patients (incidence: 1.6%) and was adjudicated as TSP-related in 35 (incidence: 1.1%; 68.6% of all tamponades). Patients of above-median age [odds ratio (OR): 2.4 (1.19-4.2), p = .006] and those undergoing re-do procedures [OR: 1.95 (1.29-3.43, p = .042] were at higher risk of TRCT. Of the operator-dependent variables, choice of transseptal needle (Endrys vs. Brockenbrough, p > .1) or puncture sheath (Swartz vs. Mullins vs. Agilis vs. Vizigo vs. Cryosheath, all p > .1) did not predict TRCT. Adjusting for operator, equipment and demographics, failure to cross the septum first pass increased TRCT risk [OR: 4.42 (2.45-8.2), p = .001], whilst top quartile operator experience [OR: 0.4 (0.17-0.85), p = .002], transoesophageal echocardiogram [TOE prevalence: 26%, OR: 0.51 (0.11-0.94), p = .023], and use of the SafeSept transseptal guidewire [OR: 0.22 (0.08-0.62), p = .001] reduced TRCT risk. An increase in transseptal guidewire use over time (2016: 15.6%, 2020: 60.2%) correlated with an annual reduction in TRCT (R2 = 0.72, p < .001) and was associated with a relative risk reduction of 70%. CONCLUSIONS: During left atrial ablation, the risk of TRCT was reduced by operator experience, TOE-guidance, and use of a transseptal guidewire, and was increased by patient age, re-do procedures, and failure to cross the septum first pass.

Risk factors for developing pacing induced LV dysfunction: Experience from a tertiary center in the UK.

BACKGROUND: The risk factors for developing pacing induced left ventricular dysfunction (LVD) in patients with high burden of right ventricular pacing (RVP) is poorly understood. Therefore, in the present study, we aimed to assess the determinants of pacing induced LVD. METHODS: Our data were retrospectively collected from 146 patients with RVP > 40% who underwent generator change (GC) or cardiac resynchronization therapy (CRT) upgrade between 2016 and 2019 who had left ventricular ejection fraction (EF) ≥50% at initial implant. RESULTS: A total of 75 patients had CRT upgrade due to pacing induced LVD (EF < 50%) and 71 patients with preserved LV function (EF ≥ 50%) had a GC. Primary indication for pacing in both groups was complete heart block. Male predominance (p = .008), prior myocardial infarction (MI) (p = .001), atrial fibrillation (AF) (p = .009), chronic kidney disease (CKD) (p = .005), and borderline low systolic function (BLSF) (EF 50%-55%) (p = .04) were more prevalent in the CRT upgrade group. Presence of AF (odds ratio [OR] = 3.05, 95% confidence interval [CI] 1.42-6.58; p = .004), BLSF (OR = 3.8, 95% CI 1.22-11.8; p = .02), and male gender (OR = 2.41, 95% CI 1.14-5.08; p = .02) were independent predictors for RVP induced LVD. Age (OR = 1.08, 95% CI 1.02-1.14; p = .005) and BLSF (OR = 5.33, 95% CI 1.26-22.5; p = .023) were independent predictors of earlier development of LVD after implant. CONCLUSIONS: Our results suggested that AF, BLSF, and male gender are predictors for development of pacing induced LVD in patients with high RVP burden. LVD can occur at any time after pacemaker implant with BLSF and increasing age associated with earlier development of LVD.

Initial experience of the High-Density Grid catheter in patients undergoing catheter ablation for atrial fibrillation.

PURPOSE: A significant proportion of patients undergoing catheter ablation for atrial fibrillation (AF) experience arrhythmia recurrence. This is mostly due to pulmonary vein reconnection (PVR). Whether mapping using High-Density Wave (HDW) technology is superior to standard bipolar (SB) configuration at detecting PVR is unknown. We aimed to evaluate the efficacy of HDW technology compared to SB mapping in identifying PVR. METHODS: High-Density (HD) multipolar Grid catheters were used to create left atrial geometries and voltage maps in 36 patients undergoing catheter ablation for AF (either due to recurrence of an atrial arrhythmia from previous AF ablation or de novo AF ablation). Nineteen SB maps were also created and compared. Ablation was performed until pulmonary vein isolation was achieved. RESULTS: Median time of mapping with HDW was 22.3 [IQR: 8.2] min. The number of points collected with HDW (13299.6±1362.8 vs 6952.8±841.9, p<0.001) and used (2337.3±158.0 vs 1727.5±163.8, p<0.001) was significantly higher compared to SB. Moreover, HDW was able to identify more sleeves (16 for right and 8 for left veins), where these were confirmed electrically silent by SB, with significantly increased PVR sleeve size as identified by HDW (p<0.001 for both right and left veins). Importantly, with the use of HDW, the ablation strategy changed in 23 patients (64% of targeted veins) with a significantly increased number of lesions required as compared to SB for right (p=0.005) and left veins (p=0.003). CONCLUSION: HDW technology is superior to SB in detecting pulmonary vein reconnections. This could potentially result into a significant change in ablation strategy and possibly to increased success rate following pulmonary vein isolation.

High sensitivity troponin and COVID-19 outcomes.

BACKGROUND: Recent reports have demonstrated high troponin levels in patients affected with COVID-19. In the present study, we aimed to determine the association between admission and peak troponin levels and COVID-19 outcomes. METHODS: This was an observational multi-ethnic multi-centre study in a UK cohort of 434 patients admitted and diagnosed COVID-19 positive, across six hospitals in London, UK during the second half of March 2020. RESULTS: Myocardial injury, defined as positive troponin during admission was observed in 288 (66.4%) patients. Age (OR: 1.68 [1.49-1.88], p < .001), hypertension (OR: 1.81 [1.10-2.99], p = .020) and moderate chronic kidney disease (OR: 9.12 [95% CI: 4.24-19.64], p < .001) independently predicted myocardial injury. After adjustment, patients with positive peak troponin were more likely to need non-invasive and mechanical ventilation (OR: 2.40 [95% CI: 1.27-4.56], p = .007, and OR: 6.81 [95% CI: 3.40-13.62], p < .001, respectively) and urgent renal replacement therapy (OR: 4.14 [95% CI: 1.34-12.78], p = .013). With regards to events, and after adjustment, positive peak troponin levels were independently associated with acute kidney injury (OR: 6.76 [95% CI: 3.40-13.47], p < .001), venous thromboembolism (OR: 11.99 [95% CI: 3.20-44.88], p < .001), development of atrial fibrillation (OR: 10.66 [95% CI: 1.33-85.32], p = .026) and death during admission (OR: 2.40 [95% CI: 1.34-4.29], p = .003). Similar associations were observed for admission troponin. In addition, median length of stay in days was shorter for patients with negative troponin levels: 8 (5-13) negative, 14 (7-23) low-positive levels and 16 (10-23) high-positive (p < .001). CONCLUSIONS: Admission and peak troponin appear to be predictors for cardiovascular and non-cardiovascular events and outcomes in COVID-19 patients, and their utilisation may have an impact on patient management.

Ethanol ablation for ventricular arrhythmias: A systematic review and meta-analysis.

INTRODUCTION: Ethanol ablation (EA) is an alternative option for subjects with ventricular arrhythmias (VAs) refractory to conventional medical and ablative treatment. However, data on the efficacy and safety of EA remain sparse. METHODS: A systematic literature search was conducted. The primary outcomes were 1) freedom from the targeted VA and 2) freedom from any VAs post-EA. Additional safety outcomes were also analyzed. RESULTS: Ten studies were selected accounting for a population of 174 patients (62.3 ± 12.5 years, 94% male) undergoing 185 procedures. The overall acute success rate of EA was 72.4% (confidence interval [CI95% ]: 65.6-78.4). After a mean follow-up of 11.3 ± 5.5 months, the incidence of relapse of the targeted VA was 24.4% (CI95% : 17.1-32.8), while any VAs post-EA occurred in 41.3% (CI95% : 33.7-49.1). The overall incidence of procedural complications was 14.1% (CI95% : 9.8-19.8), with pericardial complications and complete atrioventricular block being the most frequent. An anterograde transarterial approach was associated with a higher rate of VA recurrences and complications compared to a retrograde transvenous route; however, differences in the baseline population characteristics and in the targeted ventricular areas should be accounted. CONCLUSION: EA is a valuable therapeutic option for VAs refractory to conventional treatment and can result in 1-year freedom from VA recurrence in 60%-75% of the patients. However, anatomical or technical challenges preclude acute success in almost 30% of the candidates and the rate of complication is not insignificant, highlighting the importance of well-informed patient selection. The certainty of the evidence is low, and further research is necessary.

An overview of heart rhythm disorders and management in myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is the most common adult form of muscular dystrophy, presenting with a constellation of systemic findings secondary to a CTG triplet expansion of the noncoding region of the DMPK gene. Cardiac involvement is frequent, with conduction disease and supraventricular and ventricular arrhythmias being the most prevalent cardiac manifestations, often developing from a young age. The development of cardiac arrhythmias has been linked to increased morbidity and mortality, with sudden cardiac death well described. Strategies to mitigate risk of arrhythmic death have been developed. In this review, we outline the current knowledge on the pathophysiology of rhythm abnormalities in patients with myotonic dystrophy and summarize available knowledge on arrhythmic risk stratification. We also review management strategies from an electrophysiological perspective, attempting to underline the substantial unmet need to address residual arrhythmic risks for this population.

High-risk features and predictors of unexplained syncope in the young SCD-SOS cohort.

INTRODUCTION: The Sudden Cardiac Death-Screening of Risk FactOrS survey included a 12-lead electrocardiogram (ECG) plus a digital-based questionnaire and aimed to screen for warning signs of diseases that may course with sudden cardiac death in children and young adults. We aimed to estimate the prevalence of unexplained syncope (US) and characterize its high-risk features and predictors in this cohort. METHODS AND RESULTS: We determined the most probable etiology of transient loss of consciousness (TLOC) episodes based on clinical criteria. US was an exclusion diagnosis and we analyzed its potential clinical and ECG predictors. Among 11 878 individuals, with a mean age of 21 ± 6 (range 6-40) years old, the cumulative incidence of TLOC was 26.5%, 76.2% corresponding to females. Reflex syncope was present in 66.4%, orthostatic hypotension in 8.2%, and 14.8% of the individuals had US. Unexplained syncope was independently associated with age < 18 years old (odds ratio [OR] 1.695; 95% confidence interval [CI] 1.26-2.29, p = .001), male gender (OR 1.642; 95% CI 1.22-2.22, p = .001), participation in competitive sports (OR 1.644; 95% CI 1.01-2.66, p = .043), syncope during exertion and/or palpitations preceding syncope (OR 2.556; 95% CI 1.92-3.40, p < .001), syncope after exertion (OR 2.662; 95% CI 1.73-4.10, p < .001), fever context (OR 9.606; 95% CI 4.13-22.34, p < .001), isolated previous syncopal episode (OR 2.780; 95% CI 0.2.06-3.75, p < .001), and history of palpitations requiring medical care (OR 1.945; 95% CI 1.14-3.31, p = .014). We found no ECG predictors of US in this population. CONCLUSIONS: The cumulative incidence of TLOC in children and young adults is high and remains unexplained in an important proportion of individuals. We identified eight clinical characteristics that may be useful for the risk stratification of individuals evaluated in a nonacute setting.

Long-Term Impact of Body Mass Index on Survival of Patients Undergoing Cardiac Resynchronization Therapy: A Multi-Centre Study.

Obesity is a risk factor for heart failure (HF), but its presence among HF patients may be associated with favorable outcomes. We investigated the long-term outcomes across different body mass index (BMI) groups, after cardiac resynchronization therapy (CRT), and whether defibrillator back-up (CRT-D) confers survival benefit. One thousand two-hundred seventy-seven (1,277) consecutive patients (mean age: 67.0 ± 12.7 years, 44.1% women, and mean BMI: 28.3 ± 5.6 Kg/m2) who underwent CRT implantation in 5 centers between 2000-2014 were followed-up for a median period of 4.9 years (IQR 2.4 to 7.5). More than 10% of patients had follow-up for ≥10 years. Patients were classified according to BMI as normal: <25.0 Kg/m2, overweight: 25.0 to 29.9 Kg/m2 and obese: ≥30.0 Kg/m2. 364 patients had normal weight, 494 were overweight and 419 were obese. CRT-Ds were implanted in >75% of patients, but were used less frequently in obese individuals. The composite endpoint of all-cause mortality or cardiac transplant/left ventricular assist device (LVAD) occurred in 50.9% of patients. At 10-year follow-up, less than a quarter of patients in the lowest and highest BMI categories were still alive and free from heart transplant/LVAD. After adjustment BMI of 25 to 29.9 Kg/m2 (HR = 0.73 [95%CI 0.56 to 0.96], p = 0.023) and use of CRT-D (HR = 0.74 [95% CI 0.55 to 0.98], p = 0.039) were independent predictors of survival free from LVAD/heart transplant. BMI of 25 to 29.9 Kg/m2 at the time of implant was independently associated with favourable long-term 10-year survival. Use of CRT-D was associated with improved survival irrespective of BMI class.