Search

Class I phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases. They are super elevated in many human cancer types and exert their main cellular functions by activating Akt to trigger an array of distinct responses, affecting metabolism and cell polarity. The signal equally plays important roles in cardiovascular pathophysiology. PI3K is required for cardiogenesis and regulation of cardiac structure and function. Overexpression of PI3K governs the development of cardiac pressure overload adaptation and compensatory hypertrophy. Therefore, inhibition of PI3K shortens life span, enhances cardiac dysfunction and pathological hypertrophy. The inverse inhibition effect, however, desirably destroys many cancer cells by blocking several aspects of the tumorigenesis phenotype. Given the contrasting effects in cardio-oncology; the best therapeutic strategy to target PI3K in cancer, while maintaining or rather increasing cardiac safety is under intense investigational scrutiny. To improve our molecular understanding towards identifying cardiac safety signalling of PI3K and/or better therapeutic strategy for cancer treatment, this article reviews PI3K signalling in cardio-oncology. PI3K signalling at the interface of metabolism, inflammation and immunity, and autonomic innervation networks were examined. Examples were then given of cardiovascular drugs that target the networks, being repurposed for cancer treatment. This was followed by an intersection scheme of the networks that can be functionalised with machine learning for safety and risk prediction, diagnoses, and defining new novel encouraging leads and targets for clinical translation. This will hopefully overcome the challenges of the one-signalling-one-health-outcome alliance, and expand our knowledge of the totality of PI3K signalling in cardio-oncology. [ABSTRACT FROM AUTHOR]

Background: Men who have sex with men (MSM) bear a disproportionately high burden of new HIV infections while lagging behind other populations with respect to engagement across the HIV care continuum. General risk factors for condomless anal intercourse (CAI) among MSM are well studied but there is a paucity of partner-level data, where emerging evidence suggests that much of the variation in condom use occurs.Methods: MSM were recruited across 10 cities in India using respondent-driven sampling (RDS) from 2016-17. Among the individuals who reported sexual intercourse in the prior 6 months, condom use and partner characteristics of the last 4 partners were captured. Correlates of CAI at the individual and partner level were determined using Poisson regression models using generalized estimating equations and incorporating RDS-II weights, which weights estimates for the participant's network size.Results: Among the 8,086 individuals, 21,723 sexual partnerships were analyzed. The prevalence of CAI was 46.9% and most partners were casual or one-time (70.7%) with partner HIV status reported as unknown in 42.6% of the sexual encounters. In multivariable analyses, partner-level characteristics associated with higher likelihood of CAI included unknown partner HIV status (aPR vs. known HIV negative partner: 1.34; 95% confidence interval (CI): 1.27-1.43) and use of alcohol/ drugs prior to intercourse either sometimes (aPR 1.42; 95% CI: 1.33-1.51) or always (aPR 1.31; 95% CI: 1.23-1.41). At an individual level, any HIV treatment literacy was associated with a lower likelihood of CAI (aPR 0.80; 95% CI: 0.74-0.86).Conclusions: To reduce HIV transmission among this population of MSM across India, combination interventions are likely needed. Interventions targeting substance use and education as well as initiatives to increase self-testing are urgently needed among MSM in India and have the potential to reduce HIV transmission in this high-risk population. Trial registration ClinicalTrials.gov Identifier: NCT01686750. Date of Registration: September 18, 2012. [ABSTRACT FROM AUTHOR]

Background: The number of older women living with HIV in Africa is growing, and their health outcomes may be adversely impacted by social frailty, which reflects deficits in social resources that accumulate over the lifespan. Our objective was to adapt a Social Vulnerability Index (SVI) originally developed in Canada for use in a study of older women living with or without HIV infection in Mombasa, Kenya.Methods: We adapted the SVI using a five-step process: formative qualitative work, translation into Kiswahili, a Delphi procedure, exploration of potential SVI items in qualitative work, and a rating and ranking exercise. Four focus group discussions (FGD) were conducted (three with women living with HIV and one with HIV-negative women), and two expert panels were constituted for this process.Results: Themes that emerged in the qualitative work were physical impairment with aging, decreased family support, a turn to religion and social groups, lack of a financial safety net, mixed support from healthcare providers, and stigma as an added burden for women living with HIV. Based on the formative FGD, the expert panel expanded the original 19-item SVI to include 34 items. The exploratory FGD and rating and ranking exercise led to a final 16-item Kenyan version of the SVI (SVI-Kenya) with six domains: physical safety, support from family, group participation, instrumental support, emotional support, and financial security.Conclusions: The SVI-Kenya is a holistic index to measure social frailty among older women in Kenya, incorporating questions in multiple domains. Further research is needed to validate this adapted instrument. [ABSTRACT FROM AUTHOR]

An editorial is presented on Pulmonary vein (PV) isolation (PVI) remains the foundation of atrial fibrillation (AF) ablation with on automated methodology for AF CL evaluation, coined the FARS10‐CL measurement. Topics include objectives of evaluating the intraobserver reproducibility of this novel measurement approach; and etermining the predictive performance of the FARS10‐CL measurement on long‐term outcomes following wide antral PVI‐only ablation in a prospective cohort of patients.

Background Little is known about the impact of psychosocial factors and substance use on viral suppression among human immunodeficiency virus (HIV)–infected key populations in resource-limited settings. Accordingly, we examined the association and interactions between depression, alcohol use, and recreational drug use on viral suppression among men who have sex with men (MSM) and people who inject drugs (PWID) in India. Methods MSM and PWID were recruited across India using respondent-driven sampling (RDS). Correlates of viral suppression were determined using Poisson regression models incorporating RDS-II weights. Two-way multiplicative interactions were assessed with separate models of all combinations of the 3 variables of interest using interaction terms; 3-way interactions were evaluated by stratifying 2-way interactions by the third variable. Results Among 1454 treatment-eligible HIV-infected MSM and 1939 PWID, older age (adjusted prevalence ratio [aPR], 1.14 for MSM; 1.41 for PWID) and higher HIV treatment literacy (aPR, 1.58 for MSM; 3.04 for PWID) were positively associated with viral suppression. Among MSM, there was evidence of a synergistic negative association between severe depression and recreational drug use (aPR, 0.37 [95% confidence interval {CI},.16–.84]), alcohol dependence and recreational drug use (aPR, 0.45 [95% CI,.20–.99]), and severe depression, alcohol dependence, and recreational drug use (aPR, 0.23 [95% CI,.09–.57]). Among PWID, daily injection (aPR, 0.51 [95% CI,.31–.82]) was the primary barrier to suppression. Conclusions Incorporating psychosocial and harm-reduction services into differentiated care models targeting MSM and PWID in low-resource settings is critical to achieving the 90-90-90 HIV/AIDS targets. [ABSTRACT FROM AUTHOR]

Background Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy. Objectives The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF. Methods This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months. Results A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093). Conclusions AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741 ) [ABSTRACT FROM AUTHOR]

Introduction The right atrium (RA) is readily accessible; however, it is unclear whether changes in the RA are representative of the LA. We performed detailed biatrial electroanatomic mapping to determine the electrophysiological relationship between the atria. Methods and results Consecutive patients with persistent AF underwent biatrial electroanatomical mapping with a contact force catheter acquiring points with a CF >10 g prior to ablation. Points were analyzed for tissue voltage, complex electrograms, low voltage (<0.5 mV), scar (<0.05 mV), and conduction velocity (CV). Forty patients (mean age 59 ± 9.2 years, AF duration 12.9 ± 9.2 months, LA area: 28 ± 5.2, RA area: 25 ± 6.4 mm2, LVEF: 44 ± 15%) underwent mapping during CS pacing. Bipolar voltage (R = 0.57, P <0.001), unipolar voltage (R = 0.68, P <0.001), low voltage (<0.5 nV) (R = 0.48, P = 0.002), fractionation (R = 0.73, P <0.001), and CV (R = 0.49, P = 0.001) correlated well between atria. There was no difference in global bipolar voltage (LA 1.89 ± 0.77 vs. RA 1.77 ± 0.57 mV, P = 0.57); complex electrograms (LA 20% vs. RA 20%, P = 0.99) or low voltage (LA 15% vs. RA 16%, P = 0.84). Global unipolar voltage was significantly higher in the LA compared to the RA (2.95 ± 1.14 vs. 2.28 ± 0.65 mV, P = 0.002) and CV was significantly slower in the RA compared to the LA (0.93 ± 0.15 m/s vs. 1.01 ± 0.19 m/s, P = 0.001). Conclusion AF is associated with remodeling processes affecting both atria. The more accessible RA provides an insight into the biatrial process associated with AF in various disease states without trans-septal access. [ABSTRACT FROM AUTHOR]

There are emerging epidemics of atrial fibrillation (AF) and heart failure in most developed countries, with a significant health burden. Due to many shared pathophysiological mechanisms, which facilitate the maintenance of each condition, AF and heart failure co-exist in up to 30% of patients. In the circumstance where known structural causes of heart failure (such as myocardial infarction) are absent, patients presenting with both conditions present a unique challenge, particularly as the temporal relationship of each condition can often remain elusive from the clinical history. The question of whether the AF is driving, or significantly contributing to the left ventricular (LV) dysfunction, rather than merely a consequence of heart failure, has become ever more pertinent, especially as catheter ablation now offers a significant advancement over existing rhythm control strategies. This paper will review the inter-related physiological drivers of AF and heart failure before considering the implications from the outcomes of recent clinical trials in patients with AF and heart failure. [ABSTRACT FROM AUTHOR]

Introduction: The significance of adenosine induced dormant pulmonary vein (PV) conduction in atrial fibrillation (AF) ablation remains controversial. The optimal dose of adenosine to determine dormant PV conduction is yet to be systematically explored. Methods and Results: Consecutive patients undergoing index AF ablation received 3 adenosine doses (12, 18, and 24 mg) in a randomized blinded order, immediately after pulmonary vein isolation (PVI). Electrophysiological (PR prolongation, AV block (AVB) and PV reconnection) and hemodynamic (BP) parameters were measured. A total, 339 doses (113/dose) assessed 191 PVs in 50 patients (66% male, 72% PAF, 52% hypertensive). Dormant PV conduction occurred in 28% of patients (16.5% [32] of PVs). All cases were associated with AVB (AVB: PV reconnection vs. no PV reconnection 100% vs. 83%, P = 0.007). AVB occurred more frequently at 24 mg versus 12 mg (92% vs. 82%, P = 0.019) but not versus 18 mg (91%, P = 0.62). AVB duration progressed between 12 mg (12.0 ± 8.9 seconds), 18 mg (16.1 ± 9.1 seconds, P = 0.001), and 24 mg (19.0 ± 9.3 seconds, P < 0.001) doses. MBP fell further at 24 mg (-MBP: 27 ± 12 mmHg) and 18 mg (26 ± 13 mmHg) doses compared to 12 mg (22 ± 10 mmHg vs., P < 0.001). A significant reduction in AVB in patients >110 kg (65% vs. 91% in 70-110 kg group, P < 0.001) in response to adenosine was seen. Conclusion: An adenosine dose producing AVB is required to unmask dormant PV conduction. AVB is significantly reduced in patients >110 kg. Weight and dosing variability may in part explain the conflicting results of studies evaluating the clinical utility of adenosine in PVI. [ABSTRACT FROM AUTHOR]

Alcohol is popular in Western culture, supported by a perception that modest intake is cardioprotective. However, excessive drinking has detrimental implications for cardiovascular disease. Atrial fibrillation (AF) following an alcohol binge or the "holiday heart syndrome" is well characterized. However, more modest levels of alcohol intake on a regular basis may also increase the risk of AF. The pathophysiological mechanisms responsible for the relationship between alcohol and AF may include direct toxicity and alcohol's contribution to obesity, sleep-disordered breathing, and hypertension. We aim to provide a comprehensive review of the epidemiology and pathophysiology by which alcohol may be responsible for AF and determine whether alcohol abstinence is required for patients with AF. [ABSTRACT FROM AUTHOR]

The Impact of Known Heart Disease on AF Ablation Outcomes Background Catheter ablation for AF is an effective treatment for patients with AF and systolic LV dysfunction; however, the clinical outcome is variable. We evaluated the impact of cardiomyopathy etiology on long-term outcomes post-catheter ablation. Methods Patients undergoing AF ablation across 3 centers (2 Australian, 1 UK) from 2002 to 2014, with LVEF<45% were evaluated. Patients were stratified into those with known heart disease as a cause of cardiomyopathy (KHD), and those with idiopathic dilated cardiomyopathy (IDCM). Results One hundred and one patients (IDCM = 77, KHD = 24) with AF and LVEF <45% underwent AF ablation. The KHD group (ischemic HD in 67%) were older (61 ± 7 vs. 55 ± 11 years, P = 0.005), with a higher CHADS2 score (2.0 ± 0.8 vs. 1.6 ± 0.7, P = 0.016), but otherwise well matched. After mean follow-up of 36 ± 23 months, AF control was greater in the IDCM group (82% vs. 50% in KHD, P < 0.001). On multivariate analysis IDCM was associated with long-term AF control (P = 0.033). The IDCM group had less functional impairment at follow-up (NYHA class 1.5 ± 0.7 vs. 2.0 ± 0.8, P = 0.005) and improved LVEF (50 ± 11% vs. 38 ± 10%, P < 0.001). Super responders (EF improvement >15%) were overwhelmingly in the IDCM group (94% vs. 6%, P < 0.001) with greater AF control (89% vs. 61%, P < 0.001). All-cause mortality was significantly higher in the KHD group (17% vs. 1.3%, P = 0.002). Conclusion IDCM was associated with greater AF control, and improvement in symptoms and LVEF compared to patients with KHD post-AF ablation. AF is an important reversible cause of HF in patients with an unexplained CM and catheter ablation an effective treatment option. [ABSTRACT FROM AUTHOR]

Large-scale production of lignocellulosic biofuel is a potential solution to sustainably meet global energy needs. One-step consolidated bioprocessing (CBP) is a potentially advantageous approach for the production of biofuels, but requires an organism capable of hydrolyzing biomass to sugars and fermenting the sugars to ethanol at commercially viable titers and yields. Clostridium thermocellum, a thermophilic anaerobe, can ferment cellulosic biomass to ethanol and organic acids, but low yield, low titer, and ethanol sensitivity remain barriers to industrial production. Here, we deleted the hypoxanthine phosphoribosyltransferase gene in ethanol tolerant strain of C. thermocellum adhE*(EA) in order to allow use of previously developed gene deletion tools, then deleted lactate dehydrogenase (ldh) to redirect carbon flux towards ethanol. Upon deletion of ldh, the adhE*(EA) Δldh strain produced 30% more ethanol than wild type on minimal medium. The adhE*(EA) Δldh strain retained tolerance to 5% v/v ethanol, resulting in an ethanol tolerant platform strain of C. thermocellum for future metabolic engineering efforts. [ABSTRACT FROM AUTHOR]

A letter about prehensile force control while grasping and lifting an object in children with hemiplegic cerebral palsy (CP) is presented. Particular focus is given to a study which examined the hypothesis that anticipatory force coupling in the involved hand while walking with a hand-held object is impaired. Findings showed nearly identical average gait velocity and peak-to-peak inertial force (IF) difference while walking with hand-held object. The study also revealed impairments in the grip-inertial force coupling in the involved hand.

Background: The prevalence and impact of obesity on outcomes of atrial fibrillation (AF) ablation randomized controlled trials (RCTs) have not been well studied. Objective: To examine the proportion of participants with obesity enrolled in RCTs of AF ablation and outcomes of ablation when subgroup analysis of participants with obesity were available. Methods: We systematically searched PubMed and EMBASE for AF ablation RCTs published between January 1, 2015 to May 31, 2022. When body mass index (BMI) data were available, normal distribution was assumed and a z score was used to estimate the proportion of obesity. Results categorized by BMI or body weight status were reviewed. Authors were contacted for additional information. Results: Of 148 eligible RCTs with 30174 participants, 144 (97.30%) RCTs did not report the proportion of participants with obesity, while published information regarding BMI was available in 63.51%. Three trials excluded patients based on BMI. Using reported BMI, we estimated the proportion of participants with obesity varied greatly across these trials, ranging from 5.82%–71.9% (median 38.02%, interquartile 29.64%, 49.10%). Patients with obesity were represented in a greater proportion among trials conducted in North America (50.23%) and Asia (44.72%), compared to others (32.16%), p <.001. Subgroup analysis or analysis adjusting for BMI was reported in only 13 (8.78%) RCTs; four (30.77%) of these suggested that BMI or body weight might negatively affect primary outcomes. Conclusion: Obesity is a common comorbidity among AF patients. However, most AF ablation RCTs underreported the proportion of participants with obesity and its impact on the primary outcomes. [ABSTRACT FROM AUTHOR]

[Display omitted] Genetically modified animal studies have revealed specific expression patterns and unequivocal roles of class I PI3K isoenzymes. PI3K(p110α), a catalytic subunit of class I PI3Ks is ubiquitously expressed and is well characterised in the cardiovascular system. Given that genetic inhibition of PI3K(p110α) causes lethal phenotype embryonically, the catalytic subunit is critically important in housekeeping and biological processes. A growing number of studies underpin crucial roles of PI3K(p110α) in cell survival, proliferation, hypertrophy and arrhythmogenesis. While the studies provide great insights, the precise mechanisms involved in PI3K(p110α) hypofunction and atrial fibrillation (AF) are not fully known. AF is a well recognised clinical problem with significant management limitations. In this translational review, we attempted a narration of PI3K(p110α) hypofunction in the molecular basis of AF pathophysiology. We sought to cautiously highlight the relevance of this molecule in the therapeutic approaches for AF management per se (i.e without conditions associate with cell proliferation, like cancer), and in mitigating effects of clinical risk factors in atrial substrate formation leading to AF progression. We also considered PI3K(p110α) in AF gene association, with the aim of identifying mechanistic links between the ever increasingly well-defined genetic loci (regions and genes) and AF. Such mechanisms will aid in identifying new drug targets for arrhythmogenic substrate and AF. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic and social distancing measures elevated stress levels globally, exacerbating mental health challenges for people with HIV (PWH). We examined the effect of COVID-19-related stress on mental health among PWH in western Washington, exploring whether social support and coping self-efficacy were protective. Data on COVID-19-related stress, mental health, social support, and coping self-efficacy were collected using online surveys during the pandemic. Pre-COVID-19 mental health data were available for a subset of participants and were linked with the survey data. In the total sample (N = 373), COVID-19-stress was associated with elevated depression (PHQ-8, β = 0.21, 95%CI [0.10, 0.32]) and anxiety (GAD-7, β = 0.28, 95%CI [0.17, 0.39]). Among the subset of respondents with pre-pandemic mental health data (N = 103), COVID-19-related stress was associated with elevated PHQ-8 scores (β = 0.35, 95%CI [0.15, 0.56]) and GAD-7 scores (β = 0.35, 95%CI [0.16, 0.54]), adjusted for baseline mental health and other confounders. Coping self-efficacy was negatively associated with GAD-7 scores (β = −0.01, 95%CI [−0.01, 0.00]), while social support was negatively associated with PHQ-8 scores (β = −0.06, 95%CI [−0.12, −0.01]). Viral suppression before and during the pandemic did not differ among participants with available data. While COVID-19-related stress predicted elevated depression and anxiety symptoms among PWH, social support and coping self-efficacy were protective. [ABSTRACT FROM AUTHOR]

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation is highly effective for atrioventricular nodal re‐entrant tachycardia (AVNRT). Generally junctional rhythm (JR) is an accepted requirement for successful ablation however there is a lack of detailed prospective studies to determine the characteristics of JR and the impact on slow pathway conduction. Methods: Multicentre prospective observational study evaluating the impact of individual radiofrequency (RF) applications in typical AVNRT (slow/fast). Characteristics of JR during ablation were documented and detailed testing was performed after every RF application to determine outcome. Procedural success was defined as ≤1 AV nodal echo. Results: Sixty‐seven patients were included (mean age 53 ± 18years, 57% female and a history of SVT 2.9 ± 4.7 years). RF (50w, 60°) ablation for AVNRT was applied in 301 locations with JR in 178 (59%). Successful slow pathway modification was achieved in 66 (99%) patients with slow pathway block in 30 (46%). Success was associated with JR in all patients. Success was achieved in six patients with RF < 10 s. There was no significant difference in the CL of JR during RF between effective (587 ± 150 ms) versus ineffective (611 ± 193 ms, p =.4) applications. Inadvertent junctional beat‐atrial (JA) block with immediate termination of RF was observed in 19 (28%) patients with AVNRT no longer inducible in 14 (74%). Freedom from SVT was achieved in 66 (99%) patients at a mean follow up of 15 ± 6 months. Conclusion: In this prospective study, JR was required during RF for acute success in AVNRT. Cycle length of JR during RF was not predictive of success. Although unintended JA block during faster JR was associated with slow pathway block, this is a precursor to fast pathway block and should not be intentionally targeted. [ABSTRACT FROM AUTHOR]

Wireless networks need channel estimation (CE) to function well. Deep learning (DL) has improved 5G and future-generation network communication reliability and computational complexity. Due to its lack of statistical channel information, the least squares (LS) estimation approach has significant estimate mistakes despite its cost-effectiveness and widespread usage. The MIMO-OFDM-5G-CS-AGAN architecture improves CE for 5G and beyond networks. The suggested CE architecture uses DL to outperform LS. The suggested architecture has been specifically developed using a multipath channel profile and a MIMO system, to effectively address situations characterized by mobility-induced Doppler effects in 5G and future networks. Because of its adaptability and scalability, the suggested architecture can accommodate almost unlimited transceiver antennas. Conditional Self-Attention Generative Adversarial Networks (CS-AGAN) are at the heart of the proposed method because they reliably provide high-quality CE at low error rates. Python is used for the implementation of the suggested approach. In this case, we have the performance metrics symbol error rate (SER), bit error rate (BER), uplink sum rate, downlink sum rate, Normalized CE Error, and mean square error. When compared to current methods like MIMO-OFDM-5G-Bi-LSTM, MIMO-OFDM-5G-DNN, and MIMO-OFDM-5G-CGAN, the suggested approach achieves 13.4%, 13.02%, 12.21% lower BER and 11.23%, 6.3%, 9.08% lower SER. [ABSTRACT FROM AUTHOR]

Background: Pneumothorax is a well‐recognized complication of cardiac implantable electronic device (CIED) insertion. While AP fluoroscopy alone is the most commonly imaging technique for subclavian or axillary access, caudal fluoroscopy (angle 40°) is routinely used at our institution. The caudal view provides additional separation of the first rib and clavicle and may reduce the risk of pneumothorax. We assessed outcomes at our institution of AP and caudal fluoroscopic guided pacing lead insertion. Methods: Retrospective cohort study of consecutive patients undergoing transvenous lead insertion for pacemakers, defibrillators, and cardiac resynchronization therapy devices between 2011 and 2023. Both de novo and lead replacement/upgrade procedures were included. Data were extracted from operative, radiology, and discharge reports. All patients underwent postprocedure chest radiography. Results: Three thousand two hundred fifty‐two patients underwent insertion of pacing leads between February 2011 and March 2023. Mean age was 71.1 years (range 16–102) and 66.7% were male. Most (n = 2536; 78.0%) procedures used caudal guidance to obtain venous access, while 716 (22.0%) procedures used AP guidance alone. Pneumothoraxes occurred in five (0.2%) patients in the caudal group and five (0.7%) patients in the AP group (p =.03). Subclavian contrast venography was performed less frequently in the caudal group (26.2% vs. 42.7%, p <.01). Conclusion: Caudal fluoroscopy for axillary/subclavian access is associated with a lower rate of pneumothorax and contrast venography compared with an AP approach. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy.Objectives: The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF.Methods: This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months.Results: A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093).Conclusions: AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741). [ABSTRACT FROM AUTHOR]

Introduction: The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population. Objectives: To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF‐mediated cardiomyopathy) following CA. Methods: Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance. Results: The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p =.686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m2 age ≥ 65, p =.834; indexed left ventricular end‐diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m2 age ≥ 65, p =.681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p =.448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p >.05) albeit a higher CHADS2VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p <.001). Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38–1.48, LogRank p =.283) as was AF burden [0% (interquartile range, IQR: 0.0–2.1) vs. age ≥ 65: [0% (IQR 0.0–1.7), p =.516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p =.913), with LV recovery in the vast majority (73% vs. 69%, respectively, p =.759) at 13 (IQR: 12–16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p =.851; 6‐min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p =.066), biomarkers (ΔN‐terminal‐pro brain natriuretic peptide −139 ± 246 vs. −168 ± 181 age ≥ 65,p =.629) and HF symptoms (Short Form‐36 survey Δphysical component summary p =.483/Δmental component summary, p =.841). Conclusion: In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age. [ABSTRACT FROM AUTHOR]

Abstract: Catheter ablation has become standard of care in patients with symptomatic atrial fibrillation (AF). Although there have been significant advances in our understanding and technology, a substantial proportion of patients have ongoing AF requiring repeat procedures. Pulmonary vein isolation (PVI) is the cornerstone of AF ablation; however, it is less effective in patients with persistent as opposed to paroxysmal atrial fibrillation. Left atrial posterior wall isolation (PWI) is commonly performed as an adjunct to PVI in patients with persistent AF with nonrandomized studies showing improved outcomes. Anatomical considerations and detailed outline of the various approaches and techniques to performing PWI are detailed, and advantages and pitfalls to assist the clinical electrophysiologist successfully and safely complete PWI are described. [ABSTRACT FROM AUTHOR]

Background: The diagnostic work‐up for cardiac arrest from ventricular tachyarrhythmias occurring in younger adults and structurally normal hearts is variable and often incomplete. Methods: We reviewed records for all recipients of a secondary prevention implantable cardiac defibrillator (ICD) younger than 60 years at a single quaternary referral hospital from 2010 to 2021. Patients with unexplained ventricular arrhythmias (UVA) were identified as those with no structural heart disease on echocardiogram, no obstructive coronary disease, and no clear diagnostic features on ECG. We specifically evaluated the adoption rate of five modalities of "second‐line" cardiac investigations: cardiac magnetic resonance imaging (CMR), exercise ECG, flecainide challenge, electrophysiology study (EPS), and genetic testing. We also evaluated patterns of antiarrhythmic drug therapy and device‐detected arrhythmias and compared them with secondary prevention ICD recipients with a clear etiology found on initial assessment. Results: One hundred and two recipients of a secondary prevention ICD under the age of 60 were analyzed. Thirty‐nine patients (38.2%) were identified with UVA and were compared with the remaining 63 patients with VA of clear etiology (61.8%). UVA patients were younger (35.6 ± 13.0 vs. 46.0 ± 8.6 years, p <.001) and were more often female (48.7% vs. 28.6%, p =.04). CMR was performed in 32 patients with UVA (82.1%), whereas flecainide challenge, stress ECG, genetic testing, and EPS were only performed in a minority of patients. Overall, the use of a second‐line investigation suggested an etiology in 17 patients with UVA (43.5%). Compared to patients with VA of clear etiology, UVA patients had lower rates of antiarrhythmic drug prescription (64.1% vs. 88.9%, p =.003) and had a higher rate of device‐delivered tachy‐therapies (30.8% vs. 14.3%, p =.045). Conclusion: In this real‐world analysis of patients with UVA, the diagnostic work‐up is often incomplete. While CMR was increasingly utilized at our institution, investigations for channelopathies and genetic causes appear to be underutilized. Implementation of a systematic protocol for work‐up of these patients requires further study. [ABSTRACT FROM AUTHOR]

Key Points: Question: Does adding posterior wall isolation (PWI) to pulmonary vein isolation (PVI) improve success in patients with persistent atrial fibrillation (AF) undergoing first-time catheter ablation? Findings: In this randomized clinical trial that included 338 patients with persistent AF, there was no significant difference in 12-month freedom from recurrent atrial arrhythmia after a single procedure and without antiarrhythmic medication among those with PVI and PWI compared with PVI alone (52.4% vs 53.6%, respectively; hazard ratio, 0.99). Meaning: Among patients with persistent AF undergoing first-time catheter ablation, the addition of PWI to PVI did not improve freedom from atrial arrhythmias compared with PVI alone. Importance: Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison. Objective: To compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation. Design, Setting, and Participants: Investigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022. Interventions: The PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone. Main Outcomes and Measures: Primary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications. Results: Among 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, –1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P =.98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P =.57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P =.36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P =.47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P <.001) and ablation times (34 [SD, 21] vs 28 [SD, 12] minutes, P <.001) were significantly shorter for PVI alone. There were 6 complications for PVI with PWI and 4 for PVI alone. Conclusions and Relevance: In patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF. Trial Registration: anzctr.org.au Identifier: ACTRN12616001436460 This randomized clinical trial compares pulmonary vein isolation (PVI) vs PVI with posterior wall isolation for achieving freedom from atrial arrhythmia in adult patients with persistent atrial fibrillation undergoing first-time catheter ablation in Australia, the UK, and Canada. [ABSTRACT FROM AUTHOR]

Diffuse Fibrosis Predicts Ventricular Arrhythmia in HCM Introduction Non-sustained ventricular tachycardia (NSVT) is a risk factor for sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). We aimed to assess whether diffuse ventricular fibrosis on cardiac magnetic resonance (CMR) imaging could be a surrogate marker for ventricular arrhythmias in patients with HCM. Methods A total of 100 patients with HCM (mean age 51 ± 13 years, septal wall thickness 20 ± 5 mm) underwent CMR with a 1.5 T scanner to determine the presence of ventricular late gadolinium enhancement (LGE) for focal fibrosis, and post-contrast T1 mapping for diffuse ventricular fibrosis. The presence of NSVT was determined by Holter monitoring and a subset of high risk patients received an implantable cardioverter-defibrillator (ICD). Results NSVT was detected in 23 of 100 patients with HCM. Focal ventricular fibrosis (by LGE) was observed in 87%, with no significant difference between patients with (96%) or without NSVT (86%, P = 0.19). However, LGE mass was greater in patients with (16.5 ± 19.1 g) versus without NSVT (7.6 ± 10.2 g, P < 0.01). NSVT was associated with a significant reduction in ventricular T1 relaxation time (422 ± 54 milliseconds) versus patients without NSVT (512 ± 115 milliseconds; P < 0.001). There was significant reduction in ventricular T1 relaxation time in patients with (430 ± 48 milliseconds) versus without aborted SCD (495 ± 113 milliseconds; P = 0.01) over a mean follow-up of 40 ± 10 months. On multivariate analysis post-contrast ventricular T1 relaxation time and septal wall thickness were the only predictors of NSVT. Conclusion Post-contrast T1 relaxation time on CMR is associated with ventricular arrhythmias in patients with HCM. Diffuse ventricular fibrosis may be an important marker of arrhythmic risk in patients with HCM. [ABSTRACT FROM AUTHOR]

Aims: The impact of atrial fibrillation (AF) ablation in early heart failure with preserved ejection fraction (HFpEF) is unknown. Our aim was to determine the impact of AF ablation on symptoms and exercise haemodynamic parameters of early HFpEF. Methods and results: Symptomatic AF patients referred for index AF ablation with ejection fraction ≥50% underwent baseline quality of life questionnaires, echocardiography, cardiac magnetic resonance imaging, exercise right heart catheterisation (exRHC), and brain natriuretic peptide (BNP) testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15 mmHg or peak exercise PCWP ≥25 mmHg. Patients with HFpEF were offered AF ablation and follow‐up exRHC ≥6 months post‐ablation. Of 54 patients undergoing baseline evaluation, 35 (65%) had HFpEF identified by exRHC. HFpEF patients were older (64 ± 10 vs. 54 ± 13 years, P < 0.01), and more frequently female (54% vs. 16%, P < 0.01), hypertensive (63% vs. 16%, P < 0.001), and suffering persistent AF (66% vs. 11%, P < 0.001), compared to those without HFpEF. Twenty HFpEF patients underwent AF ablation and follow‐up exRHC 12 ± 6 months post‐ablation. Nine (45%) patients no longer fulfilled exRHC criteria for HFpEF at follow‐up. Patients remaining arrhythmia free (n = 9, 45%) showed significant improvements in peak exercise PCWP (29 ± 4 to 23 ± 2 mmHg, P < 0.01) and Minnesota Living with Heart Failure (MLHF) score (55 ± 30 to 22 ± 30, P < 0.01) while the remainder did not (PCWP 31 ± 5 to 30.0 ± 4 mmHg, P = NS; MLHF score 55 ± 23 to 25 ± 20, P = NS). Conclusion: Heart failure with preserved ejection fraction frequently coexists in patients with symptomatic AF and preserved ejection fraction. Restoration and maintenance of sinus rhythm in patients with comorbid AF and HFpEF improves haemodynamic parameters, BNP and symptoms associated with HFpEF. [ABSTRACT FROM AUTHOR]

Background: Multipolar catheters provide high‐density mapping which may reduce the procedural duration and improve the success of catheter ablation (CA) for focal arrhythmias. The high‐density grid (HDG) catheter is a 16 electrode mapping catheter with bipole recordings at orthogonal splines. The aim of this study is to compare the clinical and procedural features from a cohort who underwent CA for focal arrhythmias using multipolar mapping (MPM) with age and case‐matched cohort using point‐by‐point (PbyP) mapping. Methods: Consecutive patients undergoing CA for focal arrhythmias between October 2018 and January 2020 guided by MPM were compared with PbyP mapping with the ablation catheter over a similar period. Demographics, procedural features, and outcomes were compared. Results: A total of 54 patients (27 in MPM vs. 27 in PbyP mapping) underwent CA for 68 focal arrhythmias (26 atrial and 42 ventricular). In the MPM group, the electrogram at the successful site was significantly earlier (39 ± 11 ms) than in the PbyP group (33 ± 7 ms; p =.02). In the MPM group, the mapping time (35 ± 24 vs. 53 ± 31 min in PbyP; p =.03) and procedural duration (126 ± 42 vs. 153 ± 39 min in PbyP; p =.02) were significantly shorter. There was no significant difference in radiofrequency and fluoroscopy times, acute procedural success, and arrhythmia recurrence. Conclusion: MPM with the HDG catheter for focal tachycardias identified earlier activation times and was associated with shorter mapping and procedure duration with equivalent success to PbyP mapping. [ABSTRACT FROM AUTHOR]

D-2-hydroxyglutaric aciduria (D-2-HGA) is a rare metabolic disorder characterized by developmental delay, hypotonia, and bi-allelic mutations in D-2-hydroxyglutarate dehydrogenase (D2HGDH) or a single gain-of-function mutation in isocitrate dehydrogenase 2 (IDH2). Metaphyseal chondromatosis with D-2-hydroxyglutaric aciduria (MC-HGA) is a type of D-2-HGA that has been previously reported in ten patients (OMIM 614875), three of whom had somatic mosaicism for R132 variants in isocitrate dehydrogenase 1 (IDH1). We describe a 3-year-old boy with MC-HGA who subsequently developed acute myeloid leukemia (AML) and was found to have an IDH1 R132C mutation in a leukemic bone marrow sample. Further testing revealed presence of somatic mosaicism for IDH1 R132C variant, suggesting an association of IDH1 in inducing myeloid leukemogenesis. [ABSTRACT FROM AUTHOR]