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BACKGROUND: It is unknown whether cardiac resynchronization therapy (CRT) improves systemic metabolomic profile by enhancing left ventricular function. The observational cohort study aimed to investigate the effect of CRT on left ventricular ejection fraction (LVEF) and circulating plasma metabolites in patients who had heart failure with reduced LVEF. METHODS: We prospectively screened patients with ischemic cardiomyopathy and nonischemic cardiomyopathy who received CRT with a defibrillator for LVEF ≤35% according to current guidelines. Clinical assessment included echocardiography and device interrogation. Blood samples for metabolomic analysis were collected before CRT and at 6-month follow-up. Plasma was subjected to gas chromatography-mass spectrometry and 1 H nuclear magnetic resonance-based metabolomic analysis. RESULTS: Totally 92 patients were enrolled, with a mean age of 67.3±11.3 years (37.0% female). LVEF was significantly improved from 28.9±7.6% at baseline to 36.0±11.3% at 6 months ( P <0.001) and to 40.1±12.6% at 12 months ( P <0.001). After CRT, 42 metabolite features were significantly decreased compared with the baseline. The ketone bodies, including 3-hydroxybutyrate ( P <0.001) and acetone ( P =0.01), were reduced. A branched-chain amino acid, isoleucine, was also decreased after CRT ( P =0.01). These metabolomic changes were mainly observed in the nonischemic cardiomyopathy group, while the metabolomic profile in the ischemic cardiomyopathy group was characterized by enhanced amino acid oxidation and elevated levels of lactate and pyruvate. The improvement in LVEF positively correlated with the ratio of changes in ketone bodies and isoleucine. CONCLUSIONS: CRT may modulate the systemic plasma metabolomic profile, which correlated with improvement in left ventricular function in patients with severe heart failure with reduced ejection fraction.

Background: Right ventricular pacing (RVP) can have adverse cardiac effects and cause pacing induced cardiomyopathy (PiCM). His bundle pacing (HBP)&Left Bundle Branch area pacing (LBBAP) mimic physiologic conduction (PhysioP) and maintain biventricular synchrony. Hypothesis and Aims: Reduced left ventricular (LV) systolic function reserve in the presence of normal baseline LV ejection fraction (EF) could precede development of RV PiCM. Our aim was to compare the effects of RVP vs. PhysioP on bicycle exercise cardiopulmonary performance in patients with normal LVEF who required pacing for bradyarrhythmias. Methods: Patients with sinus rhythm and RVP or PhysioP&ventricular pacing burden of >70% who completed cardiopulmonary exercise test and simultaneous stress echocardiography (SE) were included. Pulmonary gas exchange was calculated using Ventilation/CO2 production at rest and during exercise. Changes in LV size, EF, longitudinal strain and diastolic function and gas exchange parameters were compared post and pre exercise in the 2 groups. Results: 25 of 29 patients completed the study [68 ± 23 yrs, 48% M; LVEF 56±5%, 11 RVP, 14 PhysioP]. There was no difference in baseline demographic&clinical variables, exercise duration, rest and peak heart rate and blood pressure between 2 groups. Pacing duration was 2.61±1.48 yrs in RVP vs. 0.84±0.67 yrs (p=0.003) in the Physio group. Resting echocardiographic parameters ( Table 1A) were comparable. Compared to RVP, reduction in LV end-diastolic volume (EDV) 3.4±14.1 ml vs. -23.1±18.1ml, p=0.006)&LV end-systolic volume (ESV -5.7±11.6 ml vs. -18.0±9.5ml, p=0.01) was more pronounced in the PhysioP group. Changes in LVEF, LV strain&diastolic function were not different between the 2 groups ( Table 1B ). There were no significant differences in changes in pulmonary gas exchange parameters in the 2 groups. Conclusions: In patients with normal LVEF and pacemaker dependent, RVP is associated with impaired but PhysioP with preserved LV systolic function reserve, which can be detected by exercise SE. SE may help identify patients at risk for RV PiCM. Benefit of PhysioP needs to be determined by larger studies with longer follow-up.

Background: Ibrutinib, a potent Bruton’s tyrosine kinase inhibitor with marked efficacy against hematological malignancies, is associated with the heightened risk of atrial fibrillation (AF). Although ibrutinib-induced AF is linked to enhanced oxidative stress, the underlying mechanisms remain unclear. Objective: This research aimed to explore the molecular mechanism and regulatory target in ibrutinib-induced AF. Methods: We performed in vivo electrophysiology studies using ibrutinib-treated mice, and then employed proteomic and single-cell transcriptomic analyses to identify the underlying targets and mechanisms. The effects of A-kinase anchoring protein 1 (AKAP1) depletion on mitochondrial quality surveillance (MQS) were evaluated using both in vivo and ex vivo AKAP1 overexpression models. Results: Atrial AKAP1 expression was significantly reduced in ibrutinib-treated mice, leading to inducible AF, atrial fibrosis, and mitochondrial fragmentation. These pathological changes were effectively mitigated in an overexpression model of ibrutinib-treated mice injected with an adeno-associated virus carrying Akap1. In ibrutinib-treated atrial myocytes, AKAP1 down-regulation promoted dynamin-related protein 1 (DRP1) translocation into mitochondria by facilitating DRP1 dephosphorylation at Ser637, thereby mediating excessive mitochondrial fission. Impaired MQS was also suggested by defective mitochondrial respiration, mitochondrial metabolic reprogramming, and suppressed mitochondrial biogenesis, accompanied by excessive oxidative stress and inflammatory activation. The ibrutinib-mediated MQS disturbance can be markedly improved with the inducible expression of the AKAP1 lentiviral system. Conclusions: Our findings emphasize the key role of AKAP1-mediated MQS disruption in ibrutinib-induced AF, which explains the previously observed reactive oxygen species overproduction. Hence, AKAP1 activation can be employed to prevent and treat ibrutinib-induced AF.

Introduction: The predictive value of left atrial (LA) volume and reservoir function (ResF) post-atrial fibrillation (AF) ablation has been scarcely studied. Hypothesis: Abnormal LA volume and ResF post-ablation are associated with adverse cardiovascular events. Methods: We analyzed LA maximum (LAVImax) and minimum (LAVImin) volume index, and 2 measures of ResF, emptying fraction (LAEF) and expansion index (LAEI), prospectively measured at 3-month post-procedure in patients in sinus rhythm who underwent AF ablation between 2007-2016. Composite endpoint (CE) at follow up was all-cause mortality, cardiac hospitalization (heart failure or acute ischemic event) and stroke. Results: 792 patients were studied ( age 60±10 years, 25% women ; Table 1) . Over 7.5 years [IQR 3.0-9.7], 96 (12%) patients experienced CE, which was more prevalent in patients with enlarged LA and reduced ResF. Impaired LA volumes and ResF were each independently associated with CE ( Fig.1 ), even after adjustment for clinical, demographic and echo characteristics (Model A, Fig.2 ) (LAVImax ≥35 ml/m 2 : HR 2.15 [95% CI, 1.35-3.43], p=0.001; LAVImin≥20.5 ml/m 2 : HR 2.88 [1.77-4.69], p<0.0001; LAEF<39%: HR 2.00 [1.31-3.05], p=0.001; LAEI<65%: HR 1.95 [1.27-3.01], p=0.003). ResF measures (LAEF and LAEI) were incremental to LAVImax (all p<0.05), but not LAVImin (all p>0.05; Fig.2 ). In patients with normal LA (LAVImax <35 ml/m 2 ; n=408), increased LAVImin (≥20.5 ml/m 2 ) remained associated with CE (HR 3.11 [1.45-6.67], p=0.004) and cardiac hospitalization (HR 5.81 [1.87-18.01], p=0.002). These findings were independent of AF recurrence. Conclusions: In these patients, enlarged LA and impaired ResF at 3-month post-ablation were strongly associated with adverse cardiovascular outcomes, regardless of AF recurrence. Measures of LA ResF were incremental to LAVImax. Notably, LAVImin showed the strongest associations and even identified a high-risk subgroup among patients with non-dilated LA.

Abstract Aims Pericardiocentesis is usually completed under fluoroscopy. The electroanatomic mapping (EAM) system allows visualizing puncture needle tip (NT) while displaying the electrogram recorded from NT, making it possible to obtain epicardial access (EA) independent of fluoroscopy. This study was designed to establish and validate a technique by which EA is obtained under guidance of three-dimensional (3D) EAM combined with NT electrogram. Methods and results 3D shell of the heart was generated, and the NT was made trackable in the EAM system. Unipolar NT electrogram was continuously monitored. Penetration into pericardial sac was determined by an increase in NT potential amplitude and an injury current. A long guidewire of which the tip was also visible in the EAM system was advanced to confirm EA. Epicardial access was successfully obtained without complication in 13 pigs and 22 patients. In the animals, NT potential amplitude was 3.2 ± 1.0 mV when it was located in mediastinum, 5.2 ± 1.6 mV when in contact with fibrous pericardium, and 9.8 ± 2.8 mV after penetrating into pericardial sac (all P ≤ 0.001). In human subjects, it measured 1.54 ± 0.40 mV, 3.61 ± 1.08 mV, and 7.15 ± 2.88 mV, respectively (all P &lt; 0.001). Fluoroscopy time decreased in every 4–5 cases (64 ± 15, 23 ± 17, and 0 s for animals 1–4, 5–8, 9–13, respectively, P = 0.01; 44 ± 23, 31 ± 18, 4±7 s for patients 1–7, 8–14, 15–22, respectively, P &lt; 0.001). In five pigs and seven patients, EA was obtained without X-ray exposure. Conclusion By tracking NT in the 3D EAM system and continuously monitoring the NT electrogram, it is feasible and safe to obtain EA with minimum or no fluoroscopic guidance.

AbstractAtherosclerosis is the most common cause of heart disease and stroke. Plaque thickness ≥4 mm in the ascending aorta or aortic arch is strongly correlated with cerebral embolic events and ischemic stroke. However, despite imaging workup, the cause of embolic stroke remains unidentified in many patients. Transesophageal echocardiography (TEE) is the preferred echocardiographic method for the evaluation of cardiac source of emboli. 2D TEE imaging evaluates aortic root and aortic arch in a single plane or two planes with biplane imaging. However, 2D TEE often fails to detect mobile or complex components in the ascending aorta and aortic arch plaques. The routine availability of 3D TEE in current ultrasound systems may significantly improve the assessment of aortic plaques as a potential embolic source. In this case series, we present four consecutive patients with stroke who underwent TEE by a single cardiologist for possible cardioembolic source. Some of these patients may have been labelled as “cryptogenic stroke” or “embolic stroke of undetermined source” (ESUS) due to the presence of insignificant or nonmobile ascending aortic or aortic arch plaques on 2D TEE imaging. In our four consecutive patients with ESUS who underwent TEE by a single operator, 3D TEE showed complex aortic arch plaques with ulceration with mobile components and established these plaques as the likely source of embolic stroke.

Objectives: The performed hand-held echocardiography (HHE) was evaluated and interpreted by trained advanced practice providers (APPs) on hospitalized CHF patients for image quality and interpretation by comparing with expert echocardiographer and SE findings. Background: Congestive heart failure (CHF) is associated with increased hospital admissions and mortality. While a standard echocardiogram (SE) is the gold standard for cardiac assessment, it is not readily available. Hospitalized CHF patients require rapid assessment for expedited treatment. Methods: Over 6 months, five trained APPs performed HHE on hospitalized CHF patients and interpreted: (a) left ventricular (LV) size, (b) LV ejection fraction (LVEF), and (c) right atrial pressure (RAP). The study echocardiographer reviewed and blindly interpreted the HHE images and compared them with APPs and SE findings. Kappa statistics determined the degree of agreement between APPs and the study echocardiographer’s interpretation of the HHE images and SE. Results: A total of 80 CHF patients (age 73 ± 14 years, 58% males; LVEF (by SE) 45 ± 19%; 36.3% body mass indexes ≥ 30 kg/m2) were enrolled. HHE interpretation by APPs had a good agreement for LVEF (kappa 0.79) with the study echocardiographer and SE (kappa 0.74) and a good agreement for RAP (kappa 0.67) with the study echocardiographer. The correlation between the absolute LVEF interpretation by the study echocardiographer on HHE and SE was r = 0.88 (p < 0.0001). Conclusions: Trained APPs obtained diagnostic-quality HHE images and interpreted the LV function and RAP in CHF patients in good agreement with the study echocardiographer. LVEF by HHE correlated with LVEF by SE. Our study suggests trained APPs can use HHE to evaluate LVEF and RAP in CHF patients, leading to expedited and optimized treatment.

Background: Early diagnosis of significant valvular heart disease (VHD) enables appropriate implementation of the best therapeutic strategy and follow-up. Cardiac auscultation remains suboptimal in early detection of VHD. The aim of this study was to evaluate the utility of point-of-care ultrasound (POCUS) for early detection of VHD and its severity. Methods: All consecutive patients with VHD who did not have a standard echocardiogram prior to first outpatient cardiology consultation underwent history and physical examination followed by POCUS study by an experienced physician in a general cardiology clinic from June 2017 to August 2022 at our institution. Subsequent standard transthoracic echocardiography (sTTE) was performed as the gold standard. Comparison was performed between POCUS and sTTE for the presence and severity of VHD. sTTE was performed by registered cardiac sonographers and interpreted by another cardiologist blinded to the POCUS results. Results: A total of 77 patients were studied (ge 72 ± 11 years, 58.4% males). A total of 89 significant valvular abnormalities were diagnosed. There were 39 (43.8%) cases of regurgitant VHD, 16 (18.0%) of stenotic VHD and 34 (38.2%) had evaluation for prosthetic valve function. The sensitivity (90.9%; 82.4%; 83.3%; 100%) and specificity (100%; 96.7%; 100%; 100%) were high for detecting ≥ moderate aortic regurgitation (AR), mitral regurgitation (MR), aortic stenosis (AS) and prosthetic valvular abnormality, respectively. The weighted κ coefficient between POCUS and sTTE for the assessment of ≥ moderate MR, AR and AS was 0.81 (95% CI, 0.65–0.97), 0.94 (95% CI, 0.84–1.00) and 0.88 (95% CI, 0.76–1.0), respectively, indicating excellent agreement. Conclusions: POCUS can identify patients with significant VHD and may serve as a powerful screening tool for early detection of significant VHD in the outpatient clinical practice with downstream impact on clinical management of significant VHD.

Purpose of review Early recurrence of atrial tachyarrhythmia (ERAT) during blanking period (BP) is not uncommon after catheter ablation of AF. Current guidelines and consensus statements recommend conservative treatment of ERAT. This review summarized recent studies, underlying mechanism and clinical managements of ERAT, and proposed a reconsideration of the definition and clinical significance of BP. Recent findings Recent studies have shown that the entity of ERAT in the very early phase of BP (i.e., first 4 weeks of the 3-month period) is different from those ERATs occurring late which is strongly associated with the late recurrence of atrial tachyarrhythmia. The optimal BP duration suggested by clinical observation ranges from 21 to 58 days. Using antiarrhythmic drugs and early electrical cardioversion are the effective management for ERAT, whereas re-ablation is a reasonable strategy although remains controversial. Summary The definition of BP with a shorter duration, that is, 1 month instead of 3 months post AF ablation, is supported by the observations of latest clinical studies. Recurrent atrial tachyarrhythmia beyond the 1-month time frame is associated with higher risk of late recurrence and may warrant repeat ablation. A revisit to the guideline recommendation on management of ERAT is needed to change clinical practice.

Background: Diastolic dysfunction (DD) is frequently present in patients with hypertrophic cardiomyopathy (HCM) due to abnormal left ventricular (LV) relaxation, wall hypertrophy, increased LV filling pressures and myocardial disarray and fibrosis, even though ejection fraction (EF) remains preserved until late stages. Our aim was to investigate in a large cohort whether contemporary markers of DD and increased filling pressures are associated with outcomes in these patients. Methods: We screened consecutive patients with HCM who had transthoracic echocardiography and no significant valvular heart disease. The associations of septal/lateral e’ velocity, E/e’, left atrial volume index (LAVi), and tricuspid regurgitant velocity (TR) with all-cause mortality were tested. A diastolic score (DS) was also calculated (1 point for each abnormality in e’, E/e’, TR, LAVi). Results: 1,496 patients with HCM were studied (mean age 52±15 yrs; 61% men; LV EF 69±7%; Table). Diastolic abnormalities were highly prevalent in these patients ( Table ). In the subset without septal reduction therapy (SRT; n=900), at a median followup of 9 years (IQR 7-11 yrs; n=78 deaths), increased E/e’ and DS were strongly associated with mortality (log-rank P <.0001 for both; Figure ). However, E/e’ did not remain significant in multivariable models after adjustment for known cardiac risk factors or other significant confounders ( Table ). In contrast, DS >2 remained independently associated with ~2-fold higher mortality risk (adjusted HR 1.91 [1.14-3.20, P =.01]; n=693; Table). In patients who underwent SRT (n=596), these associations showed the same trend but attenuated. Conclusion: In HCM patients who did not require SRT, the severity of DD was associated with mortality, independent of cardiac pump function or known cardiac risk factors. The composite score was more powerful than E/e’. Further studies are needed to fully understand the impact of DD in these patients with and without SRT.