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Backround: Advances in surgical and medical care of children born with congenital heart disease (CHD) has improved survival into adulthood. However, cardiac and non-cardiac morbidity and mortality remain common in adults with CHD (ACHD). We present the causes and predictors of mortality in a large cohort of ACHD patients from the USA. Methods/Approach: We conducted a retrospective review of ACHD patients followed at Mayo Clinic between 1992 - 2024. Mortality was ascertained using the Accruint national data base. Clinical characteristics and primary cause of death were identified from the electronic record. Kaplan-Meier (KM) survival analysis was performed to compare overall survival stratified by CHD severity. Cox proportional hazards regression was used to identify independent predictors of mortality. Results/Data: Amongst 9160 ACHD patients (mean age 38±16y at first visit, 51% males, 23% simple, 59% moderate and 18% severe CHD), mortality occurred in 1430(16%) patients during a mean follow-up of 11±7y. The mean age at death was 68±17 y, 58±17y, and 45±15y in mild, moderate and severe ACHD. KM analysis of survival and cause of death stratified by CHD severity are presented in Figures 2 and 3 respectively. Cause of death could not be ascertained in 33%%. Amongst those with a known cause of death, the proportion of non-cardiac death increased with decreasing severity of CHD. HF death and sudden cardiac death occurred in 11% and 19%. Infection, malignancy and chronic respiratory failure were important non-cardiac causes of death. Significant risk factors for mortality included CHD severity, ventricular arrhythmia, heart failure, declining functional capacity, diabetes and chronic kidney disease as presented in the Fig 1. Conclusion(s): Mortality in ACHD patients is associated with CHD severity, heart failure, ventricular arrhythmia and cardiovascular comorbidities. Early recognition and management of these risk factors may improve long-term survival. As patients with ACHD age, management of cardiovascular and noncardiac risk factors will require development of systems of care specific to this vulnerable population.

Background: Heart failure with preserved ejection fraction (HFpEF) accounts for approximately half of all heart failure hospitalizations; yet, tools for individualized 1-year mortality risk stratification remain limited. We conducted a retrospective study to develop and validate a machine learning model using genetic programming and automated model search to predict 1-year all-cause mortality in HFpEF patients admitted for decompensated HF. Methods: Electronic medical records from Mayo Clinic (2010-2020) were queried to identify 7,840 adult patients hospitalized with HF exacerbation and a left ventricular ejection fraction>50% on echocardiograms performed between six months pre-admission and seven days post-discharge. Demographic, clinical, laboratory, medication, comorbidity, and imaging data available at the time of index hospitalization were extracted. The cohort was split into 80% training (n=6,272) and 20% held-out test (n=1,568) sets. After standard preprocessing, we performed an evolutionary AutoML search. The final pipeline applied a RobustScaler, two sequential feature-union blocks, and an XGBoost classifier. Model performance on the test set was assessed by area under the receiver operating characteristic curve (AUC), Brier score, accuracy, precision, recall, and F1 score, each with bootstrap-derived 95% confidence intervals (CIs). For interpretability, SHAP (SHapley Additive exPlanations) values were computed using the full scaled training set as background. Results: On the held-out test set, the XGBoost-based model achieved an AUC of 0.7595 (95% CI: 0.7307-0.7870) and a Brier score of 0.1764 (95% CI: 0.1652-0.1890). Accuracy was 0.7406 (95% CI: 0.7143-0.7645), precision 0.6349 (95% CI: 0.5759-0.6942), recall 0.4135 (95% CI: 0.3636-0.4609), and F1 score 0.5008 (95% CI: 0.4529-0.5444). The global SHAP summary plot (Figure 1) ranked age, serum albumin, blood urea nitrogen (BUN), presence of renal failure, and NT-proBNP as the top 5 predictors. Conclusions: In this large HFpEF cohort, an AutoML-derived XGBoost pipeline achieved robust discrimination (AUC≈0.76) and calibration (Brier≈0.18) for 1-year mortality prediction. SHAP-based explanations highlighted the importance of age, nutritional status (albumin), renal biomarkers (BUN, renal failure), and natriuretic peptides (NT-proBNP) as principal drivers of risk. These interpretable machine learning findings may guide personalized risk stratification and identify therapeutic targets in HFpEF.

Background: Calcium release channel deficiency syndrome (CRCDS) is caused by biogenic or biophysical loss-of-function (LOF) pathogenic variants in the RYR2 -encoded ryanodine receptor (RyR2), a key intracellular Ca 2+ release channel. Previously, we identified a novel homozygous duplication involving the promoter and exons 1-4 of RYR2 , leading to 80% RyR2 protein loss and exertion-related sudden death in the young. Here, we generated a RYR2 knockout (RYR2-KO) induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM) model to explore intracellular and electrophysiological compensatory mechanisms that overcome this extreme loss of RyR2 protein. Methods: Using CRISPR/Cas9 gene editing, a homozygous c.163delT variant (p.S55Pfs*46) was inserted into a normal iPSC line (isogenic control) to create a homozygous RYR2-KO iPSC line. After re-engineering the lines into ventricular-like cardiomyocytes (iPSC-CMs), intracellular Ca 2+ handling was assessed by Fluo-4 AM cell imaging (0.5 Hz stimulation). Electrical remodeling in the L-type Ca 2+ current (I CaL ) was assessed using the whole-cell patch clamp technique. Results: Significant differences were observed in Ca 2+ transient parameters between RYR2-KO and isogenic control iPSC-CMs. Biogenic RyR2 loss significantly reduced Ca 2+ transient peak amplitude (CTA: 0.16 ± 0.01 ΔF/F0, p<0.0001) and upstroke velocity (CTV: 0.42 ± 0.06 (ΔF/F0)/t, p<0.0001), and prolonged Ca 2+ transient duration (CTD 90 : 1.59 ± 0.03 s, p=0.01) as compared to isogenic control (CTA: 0.48 ± 0.04 ΔF/F0; CTV: 1.30 ± 0.15 (ΔF/F0)/t; CTD 90 : 1.46 ± 0.05 s). Additionally, RyR2 loss abolished SR Ca 2+ leak (0.9 ± 0.9 % versus 35.1 ± 15.5 %, p=0.03). Lastly, a significant reduction in I CaL density was observed in RYR2-KO iPSC-CMs as compared to isogenic control iPSC-CMs (at 0 mV, RYR2-KO: -8.54 ± 1.60 pA/pF, control: -17.45 ± 3.69 pA/pF, p=0.0004). These data indicate that I CaL reduction may contribute to the reduced Ca 2+ transient peak. Conclusions: Complete loss of RyR2 in iPSC-CMs profoundly disrupts intracellular Ca 2+ handling, abolishes Ca 2+ sparks frequency, and secondarily down-regulates the sarcolemmal L-type Ca 2+ channel.

Background: Propofol is a first-line sedative for critically ill adults receiving invasive mechanical ventilation (IMV). However, it can contribute to hemodynamic instability, especially in the setting of intubation. The magnitude, timing, risk factors, and variability of sedation-associated mean arterial pressure (MAP) changes remain poorly characterized in ICU settings. Objectives: To quantify MAP changes following propofol sedation, identify risk factors for hemodynamic instability, and characterize associated interventions. Methods: We included adults (≥18 years old) across 11 ICUs in the Mayo Clinic Enterprise who required IMV and received ≥6 consecutive hours of propofol infusion between 05/05/2018 and 07/31/2024. The primary outcome was MAP change within 2-hours following sedation. Secondary outcomes included vasopressor use and hypotension (MAP ≤60 mmHg). Mixed-effects modeling was utilized to account for individual patient differences. The main model used a “neutral” adjustment, estimating a 5 mmHg MAP increase per 0.05 mcg/kg/min of norepinephrine equivalents, reduced to 3 mmHg per 0.05 mcg/kg/min after reaching a dose of 0.20 mcg/kg/min. Those on any vasopressors prior to propofol sedation initiation were analyzed separately. Results: Across 16,418 patients, 25.2% were on vasopressors before sedation initiation. Among the remaining 12,281 patients, 40.3% required vasopressors and 7.7% experienced hypotension within 2 hours of sedation ( Image 1 ). Post-intubation sedation was associated with a MAP reduction within the first 30 minutes (-6.58 mmHg; 95% CI: -6.85 to -6.32; P<0.001; Images 2 and 3 ). There was substantial inter-patient variability in both baseline MAP (9.5% variation attributable to between-patient differences) and MAP decline after sedation (40.9% between-patient differences). Higher SOFA scores (-0.31 mmHg per point), older age (-0.04 mmHg per year), and male sex (-0.47 mmHg) were associated with lower MAP. Patients with higher illness severity experienced progressively greater MAP changes over time (-0.20 mmHg per hour per increasing SOFA point; P<0.001). Conclusions: Propofol sedation is associated with clinically significant hemodynamic effects requiring intervention in the early post-intubation period. The marked inter-patient variability in hemodynamic responses highlights the importance of personalized management approaches. Risk stratification may help identify patients who could benefit from preemptive hemodynamic optimization.

Background: Cardiac fibrosis is a critical and independent driver of heart failure (HF), characterized by excessive extracellular matrix (ECM) deposition. Decreased CDCP1 (CUB domain-containing protein 1) expression has been associated with myocardial recovery in human genome wide association studies by attenuating PDGF-BB driven cardiac fibroblast proliferation with no effect on canonical TGF-beta mediated transdifferentiation in-vitro. In-vivo, Cdcp1 deletion significantly reduced cardiac fibrosis and dysfunction in an angiotensin II/phenylephrine-induced pressure overload mouse model. However, its upstream regulators and its downstream effects on molecular signaling pathways that modulate ECM remodeling are unknown. Hypothesis: CDCP1 promotes human cardiac fibroblast mediated ECM remodeling in the HF microenvironment. Methods: Human ventricular fibroblasts (HVF) were treated with PDGF-BB (20 ng/ml), TGF-β (10 ng/ml), or Angiotensin II (100 ng/ml) for 48 hours. CDCP1 knockdown (KD) was achieved through siRNA transfection. Gene expression analysis was performed using qRT-PCR and protein quantification by Western blot. Both intact HVF and decellularized ECM were immunostained for collagen 1 to evaluate for ECM compositional changes. Results: Individual and combination treatments with fibrotic stimuli significantly increased CDCP1 expression (Figure 1A-1B). CDCP1 KD resulted in reduction of key ECM markers COL1A1, CTGF, and LOX (Figure 1C) across all fibrotic stimuli . Immunostaining of HVF after treatment with fibrotic stimuli showed reduced collagen 1 production with CDCP1 KD (Figure 1D). Western blot analysis showed increased phosphorylation of Src (tyr416) with 6h of treatment with fibrotic stimuli which was nullified by silencing of CDCP1 (Figure 1E). Conclusion: Our findings demonstrate that CDCP1 is necessary for ECM synthesis and Src signaling across multiple profibrotic pathways. Selective targeting of CDCP1 to modulate Src signaling pathways could provide novel therapeutic avenues for HF and fibrosis treatment.

Background: The cardiac hormone atrial natriuretic peptide is the endogenous ligand for the guanylyl cyclase A (GC-A) receptor. The ANP/GC-A/cGMP pathway is a key regulator of cardiorenal and metabolic homeostasis. Beyond its classical natriuretic and vasodilatory roles, emerging evidence reveals that ANP via GC-A stimulates lipolysis in human adipocytes and modulates insulin secretion. Notably, the ANP gene variant rs5068, which enhances ANP production, is associated with reduced risk of obesity and metabolic syndrome in humans. We recently engineered CRRL191, a novel best-in-class GC-A agonist, with superior receptor activation and greater resistance to degradation by neprilysin and insulin degrading enzyme resulting in greater blood pressure lowering and natriuretic effects than ANP. Given the metabolic properties of GC-A signaling, we investigated CRRL191’s metabolic effects on lipolysis and insulin secretion in pancreatic, including its interaction with GLP-1. Hypothesis: CRRL191 exerts potent lipolytic and insulinotropic effects and synergizes with GLP-1 to enhance insulin secretion. Methods: Human visceral adipocytes were treated with CRRL191 (10 -8 -10 -6 M) for 6 hrs. Lipolysis was assessed by measuring glycerol and non-esterified fatty acids (NEFA) in supernatants. Rat pancreatic beta cells (INS-1) were stimulated treated with CRRL191 (10 -10 -10 -6 M), GLP-1 (10 -10 -10 -6 M) alone or their combination for 1 hr. Insulin secretion was quantified by ELISA. Results: CRRL191 stimulated lipolysis in human visceral adipocytes (10 -8 -10 -6 M), increasing glycerol and NEFA release. CRRL191 induced greater glycerol release than GLP-1 across all tested doses, with low dose CRRL191 (10 -10 M) notably enhancing NEFA production. In INS-1 cells, CRRL191 dose dependently increased insulin secretion under hyperglycemic conditions, demonstrating superior potency at lower concentrations (10 -10 and 10 -8 M) compared to GLP-1. Remarkably, co-administration of CRRL191 with GLP-1 amplified insulin release beyond levels achieved by either peptide alone. Conclusion: CRRL191 is a potent GC-A agonist that robustly stimulates lipolysis in visceral adipocytes and enhances insulin secretion in pancreatic beta cells. Its synergistic interaction with GLP-1 highlights a novel therapeutic avenue targeting the GC-A/cGMP pathway for integrated treatment of cardiometabolic diseases. These findings support further evaluation of CRRL191 as a promising candidate for cardiometabolic drug development.

Background: Previously, we discovered that DENND3, a guanine nucleotide exchange factor regulating Rab GTPases, influences cardiac ion channel trafficking. Both electrophysiological dysfunction and arrhythmic events were identified in variant inserted inducible pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) expressing DENND3-p.R534S. This was a novel missense variant identified in a patient with familial idiopathic ventricular fibrillation (IVF). Notably, augmented membrane retention of key cardiac ion channels was observed in both DENND3-p.R534S expressing TSA201 cells and variant inserted iPSC-CMs. To further study the mechanisms underlying arrhythmogenesis associated with IVF, intracellular calcium handling was characterized in these re-engineered heart cells with DENND3-p.R534S. Methods: Here, iPSC-CMs expressing DENND3-p.R534S and isogenic controls (IC) were studied. Optical action potentials were recorded using the FluoVolt voltage-sensitive dye at a constant pacing rate of 1 Hz. Multi-electrode array (MEA) recordings assessed beat period and conduction dynamics. Intracellular calcium dynamics were analyzed using Fluo-4 calcium imaging. Results: DENND3-p.R534S iPSC-CMs exhibited frequent arrhythmic activity, including irregular beating patterns (78%, n=28/36), alternans (25%), early afterdepolarizations (EADs, 8%), and delayed afterdepolarizations (DADs, 8%) versus 0% in IC lines (n=0/36, p<0.05). MEA recordings revealed significantly prolonged and irregular beat periods (2.59±0.26s vs. 1.37±0.10s, p<0.05), indicating electrical instability. Calcium imaging further showed significantly reduced calcium transient amplitude in DENND3-p.R534S iPSC-CMs compared to ICs (0.035±0.039ΔF/F 0 vs. 0.302±0.099ΔF/F 0 , p<0.05), and slowed upstroke velocity (0.170±0.212 ΔF/F 0 ●s -1 vs. 1.340±0.463ΔF/F 0 ●s -1 ) suggesting impaired intracellular calcium release. Conclusion: The DENND3-p.R534S variant not only disrupts ion channel distribution as shown previously but also markedly perturbs intracellular calcium handling, contributing to electrophysiological instability and arrhythmogenic cellular phenotypes. These findings highlight DENND3’s novel and emerging role in maintaining cardiac cellular homeostasis and rhythm stability.

Background: Disease-causative variants in LMNA -encoded lamin A/C cause the laminopathies, a heterogeneous group of diseases variably resulting in arrhythmogenic/dilated cardiomyopathy (ACM/DCM), lipodystrophy, muscular dystrophy, and progeria. The artificial intelligence (AI)-derived electrocardiographic age gap (AI-EAG), determined by the discrepancy between a patient’s artificial AI-enabled electrocardiogram (ECG) predicted biological age versus their chronological age, is accelerated in laminopathy. Thus, we sought to determine if the AI-EAG serves as a prognostic marker in patients with cardiac laminopathy. Methods: Retrospective analysis of 1,049 genotype-positive patients with genetic ACM/DCM was used to identify those with pathogenic/likely pathogenic (P/LP) variants in LMNA . After the exclusion of those who lacked a 12-lead ECG while in sinus rhythm, a previously trained AI-ECG age algorithm was used to determine the AI-EAG by subtracting the patient’s chronological age from the AI-ECG derived biological age. The AI-EAG was then correlated with a combined outcome of major ventricular arrhythmia [sudden cardiac arrest, sustained ventricular tachycardia, and appropriate implantable cardioverter-defibrillator shocks], heart transplantation, and cardiovascular death. Results: Overall, 147/1,049 (14%) patients with genetically-mediated ACM/DCM had a P/LP variant in LMNA . Of these, 80/147 (54%) LMNA variant-positive patients (52% female, mean chronological age 36 ± 15 years) had ECGs suitable for AI-EAG analysis. Most (52/80; 65%) had an AI-EAG >10 years with a mean AI-EAG of 17 ± 13 years. Of note, the AI-EAG was greater in those with a clinical cardiac phenotype (20 ± 14 vs. 13 ± 10 years; p = 0.011). As a continuous variable, an increased AI-EAG was associated with increased risk of the composite outcome at a median follow-up of 20 months (HR 1.036; 95% CI 1.004–1.068; p = 0.026) and AI-EAG > 10 and > 20 years were both associated with elevated risk (HR 4.272; 95% CI 1.388–13.147; p = 0.011 and HR 3.732; 95% CI 1.505–9.255; p = 0.004, respectively). Conclusion: In cardiac laminopathy, an increased AI-EAG was common and correlated with adverse cardiovascular outcomes. Non-invasive ascertainment of electrocardiographic aging by AI may provide a novel prognostic marker in cardiac laminopathy. Future studies are needed to validate this finding and further define the role of the AI-EAG in the risk-stratification of patients with cardiac laminopathy.

Background: Patients with repaired Tetralogy of Fallot (TOF) undergoing pulmonary valve replacement (PVR) are at increased risk of major adverse ventricular arrhythmias and related events (MAREs). Perioperative electrophysiological study (EPS) has been used for risk stratification and guiding future management, but these studies are limited by small sample size. Objectives: To perform a systematic review of outcomes of pre-PVR EPS in TOF patients with PVR. Methods: A comprehensive search of PubMed, Embase, Scopus and Google scholar databases was performed per PRISMA 2020 guidelines. Studies on patients with repaired TOF undergoing PVR with perioperative EPS were included. Data were extracted on study design, sample size, EPS outcomes and MAREs during follow-up. Results: A total of 1,528 patients (age: 35.5±3.8 y; 57% male; LVEF: 57.1±1.5%, RVEF: 42.6±1.5%) were included from 12 studies. EPS was performed in 1212/1528 (79.3%), with sustained VT inducibility in 404 (33.3%)-monomorphic VT in 258 (63.8%), while 808 (66.6%) were non- inducible. 8/12 studies reported the type of PVR (transcatheter-36.8%). 174/293 (59.3%) inducible patients had an ablation (9 studies), while ICD (6 studies) was implanted in 70/263 (26.6%). Follow-up EPS (6 studies) showed 35/230 (15.2%) remained inducible. Overall,113 (9.3%) patients experienced MAREs over a median follow-up ranging from 6 months to 6.7 years. Sustained VT (11/12 studies) occurred in 70/1092 (6.4%), appropriate ICD therapy (7/12 studies) in 13/622 (2.1%) and sudden cardiac death (10/12 studies) in 30/906 (3.3%). Five studies provided MARE data stratified by VT inducibility. 12/164 (7.3%) inducible patients experienced MAREs, compared to 2/318 (0.6%) non-inducible patients. Reported risk factors for MAREs included older age at initial repair and PVR, QRS duration (>180ms), LVEF <45%, RVEF <35%, history of syncope, prior palliative shunts and atrial arrhythmias. Some studies identified MRI-derived scar burden, pulmonary annulus size, and RV/LV volume ratios as additional predictors. Conclusion: TOF patients remain at high risk of VA after PVR with 1/10 patients experiencing MAREs. People with inducible VT had a 12-fold greater risk than people who were non-inducible. EPS identifies a subset of TOF patients at higher arrhythmic risk during PVR and supports tailored ablation and ICD strategies. Prospective multicentre studies are needed to optimize integration of EPS and clinical risk models.

Introduction: Infective endocarditis (IE) is a severe intracardiac infection, often requiring intensive care unit (ICU) admission. Despite early surgical intervention, mortality remains high. Data for patients admitted to the cardiac intensive care unit (CICU) is especially limited. Research Question: We aimed to investigate the short and long-term outcomes of patients with IE admitted to the CICU. Methods: We conducted a retrospective cohort study of adult patients admitted to the Mayo Clinic CICU (2007-2018) with confirmed acute IE, identified via database query and manual chart review. Patients were further categorized by cardiac surgery status: performed, indicated but declined, or not indicated. Primary outcomes were all-cause mortality at 30-days and 1-year, analyzed using Kaplan-Meier and Cox proportional-hazard analysis. Models were adjusted for known predictors. Results: Overall, 233 CICU patients met criteria for IE. Median age was 64.0 years; 49 were female. In total, 104 patients had native valve IE; 128 had prosthetic or implantable device-associated IE. Staphylococcus aureus was the most prevalent organism (42.7%) and was present in 72.4% of 30-day deaths. Cardiac surgery was indicated in 182 (78.1%) patients - 129 patients underwent surgery, while 53 declined; 48 patients did not have indications. By 30 days, 58 (24.9%) patients died; significant predictors included older age, higher illness severity scores, and greater need for critical care therapies. The 30-day mortality estimates were markedly higher for patients who declined surgery (60.4%, adj. HR 4.17, 95% CI 2.02-8.52, p <0.001), and lower for those who received surgery vs those without surgical indications (11.9% vs 23.8%, adj. HR 0.44, 95% CI 0.20-0.98, p=0.04) (Figure 1). By 1-year, 93 (39.9%) patients died, including 36 (20.5%) hospital survivors. The 1-year mortality estimates were markedly higher for patients who declined surgery (85.1%, adj. HR 5.46, 95% CI 2.87-10.39, p <0.001), but was similar for patients who received surgery to those without surgical indications (31.8% vs 29.3%, adj. HR 0.94, 95% CI 0.49-1.78, p=0.84) (Figure 2). Conclusion: IE requiring CICU admission carries substantial mortality despite acute management. Higher severity scores, comorbidities, and intensive care interventions predict mortality. Early cardiac surgery improved short-term outcomes, but long-term mortality remains high.