Small conductance calcium-activated potassium channel contributes to stress induced endothelial dysfunctions.

Patients with Takotsubo syndrome displayed endothelial dysfunction, but underlying mechanisms have not been fully clarified. This study aimed to explore molecular signalling responsible for catecholamine excess induced endothelial dysfunction. Human cardiac microvascular endothelial cells were challenged by epinephrine to mimic catecholamine excess. Patch clamp, FACS, ELISA, PCR, and immunostaining were employed for the study. Epinephrine (Epi) enhanced small conductance calcium-activated potassium channel current (ISK1-3) through activating α1 adrenoceptor. Phenylephrine enhanced edothelin-1 (ET-1) and reactive oxygen species (ROS) production, and the effects involved contribution of ISK1-3. H2O2 enhanced ISK1-3 and ET-1 production. Enhancing ISK1-3 caused a hyperpolarization, which increases ROS and ET-1 production. BAPTA partially reduced phenylephrine-induced enhancement of ET-1 and ROS, suggesting that α1 receptor activation can enhance ROS/ET-1 generation in both calcium-dependent and calcium-independent ways. The study demonstrates that high concentration catecholamine can activate SK1-3 channels through α1 receptor-ROS signalling and increase ET-1 production, facilitating vasoconstriction.

Effect of anaemia and iron deficiency in heart failure with mildly reduced ejection fraction.

OBJECTIVE: The present study aims to clarify the prevalence and prognostic impact of anaemia and iron deficiency in patients with heart failure with mildly reduced ejection fraction (HFmrEF). BACKGROUND: The prognostic impact of anaemia and iron deficiency in HFmrEF has not yet been clarified. METHODS: Consecutive patients with HFmrEF were retrospectively included at one institution from 2016 to 2022. Patients with anaemia (i.e. haemoglobin <13 g/dL in males and < 12 g/dL in females) were compared to patients without, respectively patients with or without iron deficiency. The primary endpoint was all-cause mortality at 30 months (median follow-up), secondary endpoints comprised HF-related rehospitalisation. RESULTS: Two thousand one hundred and fifty four patients with HFmrEF with a median haemoglobin level of 12.2 g/dL were included. Anaemia was present in 52% of patients with HFmrEF and associated with a higher risk of all-cause mortality (44% vs. 18%; HR = 3.021; 95% CI 2.552-3.576; p =.001) and HF-related rehospitalisation (18% vs. 8%; HR = 2.351; 95% CI 1.819-3.040; p =.001) at 30 months, which was confirmed after multivariable adjustment. Although iron status was infrequently assessed in anaemics with HFmrEF (27%), the presence of iron deficiency was associated with higher risk of rehospitalisation for worsening HF (25% vs. 15%; HR = 1.746; 95% CI 1.024-2.976; p =.038), but not all-cause mortality (p =.279) at 30 months. CONCLUSION: Anaemia and iron deficiency are very common in atleast half of patients with HFmrEF and independently associated with adverse long-term prognosis.

Roles and Mechanisms of Dopamine Receptor Signaling in Catecholamine Excess Induced Endothelial Dysfunctions.

Endothelial dysfunction may contribute to pathogenesis of Takotsubo cardiomyopathy, but mechanism underlying endothelial dysfunction in the setting of catecholamine excess has not been clarified. The study reports that D1/D5 dopamine receptor signaling and small conductance calcium-activated potassium channels contribute to high concentration catecholamine induced endothelial cell dysfunction. For mimicking catecholamine excess, 100 µM epinephrine (Epi) was used to treat human cardiac microvascular endothelial cells. Patch clamp, FACS, ELISA, PCR, western blot and immunostaining analyses were performed in the study. Epi enhanced small conductance calcium-activated potassium channel current (ISK1-3) without influencing the channel expression and the effect was attenuated by D1/D5 receptor blocker. D1/D5 agonists mimicked the Epi effect, suggesting involvement of D1/D5 receptors in Epi effects. The enhancement of ISK1-3 caused by D1/D5 activation involved roles of PKA, ROS and NADPH oxidases. Activation of D1/D5 and SK1-3 channels caused a hyperpolarization, reduced NO production and increased ROS production. The NO reduction was membrane potential independent, while ROS production was increased by the hyperpolarization. ROS (H2O2) suppressed NO production. The study demonstrates that high concentration catecholamine can activate D1/D5 and SK1-3 channels through NADPH-ROS and PKA signaling and reduce NO production, which may facilitate vasoconstriction in the setting of catecholamine excess.

[Treatment with cardiac electronic implantable devices]. / Therapie mit kardialen elektronischen implantierbaren Devices.

Cardiac device therapy provides not only treatment options for bradyarrhythmia but also advanced treatment for heart failure and preventive measures against sudden cardiac death. In heart failure treatment it enables synergistic reverse remodelling and reduces pharmacological side effects. Cardiac resynchronization therapy (CRT) has revolutionized the treatment of reduced left ventricular ejection fraction (LVEF) and left bundle branch block by decreasing the mortality and morbidity with improvement of the quality of life and resilience. Conduction system pacing (CSP) as an alternative method of physiological stimulation can improve heart function and reduce the risk of pacemaker-induced cardiomyopathy. Leadless pacers and subcutaneous/extravascular defibrillators offer less invasive options with lower complication rates. The prevention of infections through preoperative and postoperative strategies enhances the safety of these therapies.

Protein Kinase D Plays a Crucial Role in Maintaining Cardiac Homeostasis by Regulating Post-Translational Modifications of Myofilament Proteins.

Protein kinase D (PKD) enzymes play important roles in regulating myocardial contraction, hypertrophy, and remodeling. One of the proteins phosphorylated by PKD is titin, which is involved in myofilament function. In this study, we aimed to investigate the role of PKD in cardiomyocyte function under conditions of oxidative stress. To do this, we used mice with a cardiomyocyte-specific knock-out of Prkd1, which encodes PKD1 (Prkd1loxP/loxP; αMHC-Cre; PKD1 cKO), as well as wild type littermate controls (Prkd1loxP/loxP; WT). We isolated permeabilized cardiomyocytes from PKD1 cKO mice and found that they exhibited increased passive stiffness (Fpassive), which was associated with increased oxidation of titin, but showed no change in titin ubiquitination. Additionally, the PKD1 cKO mice showed increased myofilament calcium (Ca2+) sensitivity (pCa50) and reduced maximum Ca2+-activated tension. These changes were accompanied by increased oxidation and reduced phosphorylation of the small myofilament protein cardiac myosin binding protein C (cMyBPC), as well as altered phosphorylation levels at different phosphosites in troponin I (TnI). The increased Fpassive and pCa50, and the reduced maximum Ca2+-activated tension were reversed when we treated the isolated permeabilized cardiomyocytes with reduced glutathione (GSH). This indicated that myofilament protein oxidation contributes to cardiomyocyte dysfunction. Furthermore, the PKD1 cKO mice exhibited increased oxidative stress and increased expression of pro-inflammatory markers interleukin (IL)-6, IL-18, and tumor necrosis factor alpha (TNF-α). Both oxidative stress and inflammation contributed to an increase in microtubule-associated protein 1 light chain 3 (LC3)-II levels and heat shock response by inhibiting the mammalian target of rapamycin (mTOR) in the PKD1 cKO mouse myocytes. These findings revealed a previously unknown role for PKD1 in regulating diastolic passive properties, myofilament Ca2+ sensitivity, and maximum Ca2+-activated tension under conditions of oxidative stress. Finally, we emphasized the importance of PKD1 in maintaining the balance of oxidative stress and inflammation in the context of autophagy, as well as cardiomyocyte function.

Cardiac damage and tropism of severe acute respiratory syndrome coronavirus 2.

Until now, the World Health Organization registered over 771 million cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection worldwide, of which 6.97 million resulted in death. Virus-related cardiovascular events and pre-existing heart problems have been identified as major contributing factors to global infection-related morbidity and mortality, emphasizing the necessity for risk assessment and future prevention. In this review, we highlight cardiac manifestations that might arise from an infection with SARS-CoV-2 and provide an overview of known comorbidities that worsen the outcome. Additionally, we aim to summarize the therapeutic strategies proposed to reverse virus-associated myocardial damage, which will be further highlighted in this review, with an outlook to successful recovery and prevention.

Ion Channel Diseases as a Cause of Sudden Cardiac Death in Young People: Aspects of Their Diagnosis, Treatment, and Pathogenesis.

BACKGROUND: Sudden cardiac death (SCD) is the death of an apparently healthy person within one hour of the onset of symptoms, or within 24 hours of last being seen alive and well-with no evidence of an extra-cardiac cause. In autopsied cases, SCD is defined as the natural unexpected death of unknown or cardiac cause. The reported incidence figures for SCD vary widely. METHODS: This review is based on clinical registry studies, meta-analyses, randomized controlled trials, systematic reviews, and current guidelines that were retrieved by a selective search in PubMed employing the key words "channelopathy," "Brugada syndrome," "long QT syndrome," "catecholaminergic polymorphic ventricular tachycardia," "short QT syndrome," and "early repolarization." RESULTS: Approximately 18% of cases of SCD in young persons are associated with cardiac channelopathy. The most common ion channel diseases affecting the heart are long QT syndrome and Brugada syndrome. The diagnosis is established by specific ECG abnormalities in the absence of structural heart disease. These can be unmasked by various maneuvers, e.g., the administration of sodium-channel blockers in Brugada syndrome. Imaging studies such as echocardiography, coronary angiography, and computed tomography are used to rule out structural heart disease and coronary artery disease. Long-term ECG and risk stratification scores can be useful aids to therapeutic decision-making. For some of these diseases, it is advisable for the patient to avoid particular triggers of ECG changes and cardiac arrhythmias in his or her everyday life. The near relatives of persons with congenital ion channel diseases should undergo clinical and genetic screening to protect them from SCD. CONCLUSION: The affected families should be investigated systematically so that appropriate diagnoses and treatments can be established.

Prognostic Impact of Left Compared to Right Heart Function in Sepsis and Septic Shock.

This study investigates the prognostic impact of left ventricular ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE) in patients with sepsis and septic shock. Consecutive patients with sepsis and septic shock were included from 2019 to 2021. LVEF and TAPSE were assessed during the first 24 hours of intensive care unit (ICU) treatment. Patients were stratified by LVEF of less than 45% and greater than or equal to 45%. The primary endpoint was 30 day all-cause mortality. Two hundred ninety-two consecutive patients were included, of which 26% presented with LVEF of less than 45%. Within the entire study cohort (60% vs. 48%; hazard ratio [HR] = 1.414; 95% confidence interval [CI] = 0.999-2.001; p = 0.050) and specifically in patients with sepsis (58% vs. 36%; HR = 1.919; 95% CI = 1.148-3.208; p = 0.013), LVEF of less than 45% was associated with an increased risk of 30 day all-cause mortality, whereas TAPSE of less than 17 mm was not (56% vs. 52%; log rank p = 0.798). Even after multivariable adjustment, LVEF of less than 45% was accompanied by a worse prognosis in septic patients (HR = 1.944; 95% CI = 1.084-3.485; p = 0.026). Contrarily, LVEF < 45% was not accompanied with increased mortality in septic shock patients (63% vs. 67%; log rank p = 0.847; HR = 0.956; 95% CI 0.596-1.533; p = 0.853). In conclusion, impaired LVEF was associated with increased mortality in septic patients without shock, but not in patients with septic shock. In contrast, impaired right ventricular function was not associated with adverse prognosis in both conditions.

Effect of Heart Failure Pharmacotherapies in Patients with Heart Failure with Mildly Reduced Ejection Fraction.

OBJECTIVE: The study sought to comprehensively investigate the effect of heart failure (HF) pharmacotherapies in patients with heart failure with mildly reduced ejection fraction (HFmrEF). BACKGROUND: In the absence of randomized controlled trials, guideline recommendations concerning HF-related therapies in patients with HFmrEF are limited. METHODS: Consecutive patients hospitalized with HFmrEF were retrospectively included at one institution from 2016 to 2022. The prognostic value of treatment with beta-blockers (BB), angiotensin-converting enzyme inhibitors, receptor blockers or receptor-neprilysin inhibitor (ACEi/ARB/ARNI), mineralocorticoid receptor antagonists (MRA) and sodium-glucose transport protein 2 inhibitors (SGLT2i) was investigated for all-cause mortality at 30 months (median follow-up) and HF-related rehospitalization. RESULTS: 2,109 patients with HFmrEF were included. Treatment with BB (27.0% vs. 35%; HR = 0.737; 95% CI 0.617-0.881; p = 0.001), ACEi/ARB/ARNI (25.9% vs. 37.6%; HR = 0.612; 95% CI 0.517-0.725; p = 0.001) and SGLT2i (11.9% vs. 29.5%; HR = 0.441; 95% CI 0.236-0.824; p = 0.010) was associated with lower risk of 30-months all-cause mortality, which was still demonstrated after multivariable adjustment and propensity score matching. In contrast, MRA treatment was not associated with long-term prognosis. The risk of HF-related rehospitalization was not affected by HF pharmacotherapies. Finally, the lowest risk of long-term all-cause mortality was observed in patients with combined use of BB, ACEi/ARB/ARNI and SGLT2i (HR = 0.456; 95% CI 0.227-0.916; p = 0.027). CONCLUSION: BB, ACEi/ARB/ARNI and SGLT2i were independently associated with lower risk of all-cause mortality in patients with HFmrEF, specifically when applied as combined "HF triple therapy". Randomized studies are needed to investigate the effect of HF-related pharmacotherapies in patients with HFmrEF.

Although heart failure with mildly reduced ejection fraction (HFmrEF) affects one out of four patients with heart failure (HF), limited evidence regarding HF pharmacotherapies for the treatment of patients with HFmrEF is available. The present study investigates the treatment with beta-blockers (BB), angiotensin-converting enzyme inhibitors, receptor blockers or receptor-neprilysin inhibitor (ACEi/ARB/ARNI), mineralocorticoid receptor antagonists (MRA) and sodium-glucose transport protein 2 inhibitors (SGLT2i) on long-term outcomes using a large registry-based dataset of 2,109 patients hospitalized with HFmrEF. Treatment with BB, ACEi/ARB/ARNI and SGLT2i was independently associated with a lower risk of long-term all-cause mortality, even after multivariable adjustment and propensity score matching, specifically when applied in combination. In contrast, MRA treatment was not associated with outcomes in the present study. The present study supports the evidence that patients with HFmrEF may benefit from HF pharmacotherapies similar than patients with HF with reduced ejection fraction (HFrEF).

Prognostic impact of prior LVEF in patients with heart failure with mildly reduced ejection fraction.

AIMS: As there is limited evidence regarding the prognostic impact of prior left ventricular ejection fraction (LVEF) in patients with heart failure with mildly reduced ejection fraction (HFmrEF), this study investigates the prognostic impact of longitudinal changes in LVEF in patients with HFmrEF. METHODS: Consecutive patients with HFmrEF (i.e. LVEF 41-49% with signs and/or symptoms of HF) were included retrospectively in a monocentric registry from 2016 to 2022. Based on prior LVEF, patients were categorized into three groups: stable LVEF, improved LVEF, and deteriorated LVEF. The primary endpoint was 30-months all-cause mortality (median follow-up). Secondary endpoints included in-hospital and 12-months all-cause mortality, as well as HF-related rehospitalization at 12 and 30 months. Kaplan-Meier and multivariable Cox proportional regression analyses were applied for statistics. RESULTS: Six hundred eighty-nine patients with HFmrEF were included. Compared to their prior LVEF, 24%, 12%, and 64% had stable, improved, and deteriorated LVEF, respectively. None of the three LVEF groups was associated with all-cause mortality at 12 (p ≥ 0.583) and 30 months (31% vs. 37% vs. 34%; log rank p ≥ 0.376). In addition, similar rates of 12- (p ≥ 0.533) and 30-months HF-related rehospitalization (21% vs. 23% vs. 21%; log rank p ≥ 0.749) were observed. These findings were confirmed in multivariable regression analyses in the entire study cohort. CONCLUSION: The transition from HFrEF and HFpEF towards HFmrEF is very common. However, prior LVEF was not associated with prognosis, likely due to the persistently high dynamic nature of LVEF in the follow-up period.

Mortality and rehospitalization in patients with pre-existing implantable pacemakers undergoing catheter ablation are related to increased comorbidity burden-data from the German Ablation Registry.

BACKGROUND: Catheter ablation of atrial fibrillation and atrial flutter is routinely performed in patients with implantable devices. The aim of the present study was to assess success rates and potential complications in a large registry cohort of patients with cardiac pacemakers. METHODS AND RESULTS: The German Ablation Registry is a nationwide, prospective registry with a 1-year follow-up investigating patients who underwent catheter ablation of supraventricular arrhythmias in 51 German centers. The present analysis focussed on the presence of cardiac pacemakers in 591 patients undergoing catheter ablation of atrial fibrillation or atrial flutter. These were compared to 7393 patients without a pacemaker. Patients with pacemakers were significantly older and presented more comorbidities like diabetes, renal failure, cardiovascular disease, or previous stroke. One-year mortality (2.4% vs. 1.3%, p = 0.022) and a combined endpoint of death, myocardial infarction, and stroke (3.6% vs. 2.1%, p = 0.014) were significantly elevated in patients with pacemakers. Re-hospitalization was also more common in patients with a pacemaker (53.3% vs. 45.0%, p < 0.01). After adjustment for important comorbidities, pre-existing pacemaker systems did not show any negative effect. Procedural success was reported in 98.8% vs. 98.4% (p = 0.93). Device-related complications were only observed in 0.4% of patients with pacemakers. CONCLUSION: Patients with pacemaker systems undergoing catheter ablation of atrial fibrillation or atrial flutter demonstrate an increased risk of death, cardiovascular events, and re-hospitalization. This observation can be largely attributed to an older patient population and an increased rate of comorbidities.

Prognostic Implications of Septal Hypertrophy in Patients with Heart Failure with Mildly Reduced Ejection Fraction.

Cardiac remodeling is frequently observed in patients with heart failure (HF) and serves as an indicator of disease progression and severity. Septal hypertrophy represents an aspect of remodeling that can be easily assessed via an echocardiographic measurement of the interventricular septal end diastole (IVSd), but it has not been evaluated for its prognostic value, particularly in patients with heart failure with mildly reduced ejection fraction (HFmrEF). We retrospectively included 1881 consecutive patients hospitalized with HFmrEF (i.e., a left ventricular ejection fraction of 41-49% and signs and/or symptoms of HF) at one institution during a study period from 2016 to 2022. Septal hypertrophy, defined as an IVSd > 12 mm, was prevalent in 34% of the HFmrEF patients. Although septal hypertrophy was not associated with all-cause mortality at 30 months (median follow-up) (HR = 1.067; 95% CI: 0.898-1.267; p = 0.460), it was associated with an increased risk of hospitalization due to worsening HF at 30 months (HR = 1.303; 95% CI: 1.008-1.685; p = 0.044), which was confirmed even after multivariable adjustment (HR = 1.340; 95% CI: 1.002-1.792; p = 0.049) and propensity score matching (HR = 1.399; 95% CI: 1.002-1.951; p = 0.048). Although septal hypertrophy was not associated with the risk of all-cause mortality in patients with HFmrEF, it was identified as an independent predictor of long-term HF-related rehospitalization.

Obesity Paradox in Heart Failure with Mildly Reduced Ejection Fraction.

Objective: The study investigates the prognostic impact of body mass index (BMI) in patients hospitalized with heart failure with mildly reduced ejection fraction (HFmrEF). Background: Limited data regarding the prognostic impact of BMI in patients with HFmrEF is available. Methods: Consecutive patients with HFmrEF (ie, left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. Risk stratification was performed according to WHO-defined BMI groups. The primary endpoint was all-cause mortality at 30 months (median follow-up). Kaplan-Meier, uni- and multivariable Cox proportional regression analyses were applied for statistics. Results: 1832 consecutive patients with HFmrEF were included with a median BMI of 26.7 kg/m2 (IQR 24.0-30.8 kg/m2). Patients with lowest BMI (ie, 18.5-24.9 kg/m2) were associated with highest risk of all-cause mortality at 30 months compared to patients with higher BMI values (40.0% vs 29.0% vs 21.4% vs 20.9%; log rank p = 0.001; HR = 0.721; 95% CI 0.656-0.793; p = 0.001). Even after multivariable adjustment, higher BMI values were associated with improved survival at 30 months (HR = 0.963; 95% CI 0.943-0.985; p = 0.001). In contrast, the risk of HF- related rehospitalization at 30 months was not affected by BMI (log rank p = 0.064). Conclusion: In patients hospitalized with HFmrEF, lower BMI was associated with increased risk of all-cause mortality at 30 months, suggesting an obesity paradox in HFmrEF.

Prognostic performance of the SCAI shock classification at admission and during ICU treatment: A retrospective, observational cohort study.

BACKGROUND: Cardiogenic shock (CS) is characterized by high mortality and requires accurate prognostic tools to predict outcomes and guide treatment. The Society for Cardiovascular Angiography and Interventions (SCAI) shock classification indicates shock severity and can be used for outcome prediction. OBJECTIVE: Here, we compare the prognostic performance of SCAI shock classification determined on admission and during intensive care unit (ICU) stay. METHODS: We included all patients with CS or conditions associated with developing CS based on ICD codes. SCAI shock stages were determined on admission and during the first 5 days of ICU stay. Receiver operating curves were used to compare the prognostic performance of SCAI stages on admission, SCAI stages during ICU stay and CS evolution (absent, resolved, persistent and new onset) for in-hospital mortality. RESULTS: Between 01/2018 and 06/2022, 1303 patients were identified and 862 patients were included. On admission, 50.6 % patients had SCAI shock stage A, 3.9 % SCAI shock stage B, 17.7 % SCAI shock stage C, 7.0 % SCAI shock stage D and 20.8 % SCAI shock stage E. Shock stage distribution changed dynamically during ICU stay. Compared to SCAI stage on admission (AUC 0.80; 95 % CI 0.77-0.83), highest achieved SCAI stage during ICU (AUC 0.86, 95 % CI 0.83-0.89, p < 0.0001) and shock evolution (AUC 0.87, 95 % CI 0.85-0.90, p < 0.0001) yielded better prognostic performance. CONCLUSIONS: SCAI shock stages changed dynamically during ICU stay, and prognostic performance can be improved by considering highest achieved SCAI shock stage as well as the evolution of CS compared to SCAI shock stage on admission.

Ejection Fraction-Related Differences of Baseline Characteristics and Outcomes in Troponin-Positive Patients without Obstructive Coronary Artery Disease.

Background: The development and course of myocardial infarction with non-obstructive coronary artery (MINOCA) disease is still not fully understood. In this study, we aimed to examine the baseline characteristics of in-hospital outcomes and long-term outcomes of a cohort of troponin-positive patients without obstructive coronary artery disease based on different left ventricular ejection fractions (LVEFs). Methods and results: We included a cohort of 254 patients (mean age: 64 (50.8-75.3) years, 120 females) with suspected myocardial infarction and no obstructive coronary artery disease (MINOCA) in our institutional database between 2010 and 2021. Among these patients, 170 had LVEF ≥ 50% (84 females, 49.4%), 31 patients had LVEF 40-49% (15 females, 48.4%), and 53 patients had LVEF < 40% (20 females, 37.7%). The mean age in the LVEF ≥ 50% group was 61.5 (48-73) years, in the LVEF 40-49% group was 67 (57-78) years, and in the LVEF < 40% group was 68 (56-75.5) years (p = 0.05). The mean troponin value was highest in the LVEF < 40% group, at 3.8 (1.7-4.6) µg/L, and lowest in the LVEF ≥ 50% group, at 1.1 (0.5-2.1) µg/L (p = 0.05). Creatine Phosphokinase (CK) levels were highest in the LVEF ≥ 50% group (156 (89.5-256)) and lowest in the LVEF 40-49% group (127 (73-256)) (p < 0.05), while the mean BNP value was lowest in the LVEF ≥ 50% group (98 (48-278) pg/mL) and highest in the <40% group (793 (238.3-2247.5) pg/mL) (p = 0.001). Adverse in-hospital cardiovascular events were highest in the LVEF < 40% group compared to the LVEF 40-49% group and the LVEF ≥ 50% group (56% vs. 55% vs. 27%; p < 0.001). Over a follow-up period of 6.2 ± 3.1 years, the all-cause mortality was higher in the LVEF < 40% group compared to the LVEF 40-49% group and the LVEF ≥ 50% group. Among the different factors, LVEF < 40% and LVEF 40-49% were associated with an increased risk of in-hospital cardiovascular events in the multivariable Cox regression analysis. Conclusions: LVEF has different impacts on in-hospital cardiovascular events in this cohort. Furthermore, LVEF influences long-term all-cause mortality.

Characteristics Associated with Ventricular Tachyarrhythmias and Their Prognostic Impact in Heart Failure with Mildly Reduced Ejection Fraction.

Background: The occurrence of ventricular tachyarrhythmias represents an established risk factor of mortality in heart failure (HF). However, data concerning their prognostic impact in heart failure with mildly reduced ejection fraction (HFmrEF) is limited. Therefore, the present study aims to investigate patient characteristics associated with ventricular tachyarrhythmias and their prognostic impact in patients with HFmrEF. Methods: Consecutive patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. The prognosis of patients with HFmrEF and different types of ventricular tachyarrhythmias (i.e., non-sustained ventricular tachycardia (nsVT), sustained VT (sVT), and ventricular fibrillation (VF) was investigated for the primary endpoint of long-term all-cause mortality at 30 months. Secondary endpoints included in-hospital all-cause mortality and long-term HF-related rehospitalization at 30 months. Results: From a total of 2184 patients with HFmrEF, 4.4% experienced ventricular tachyarrhythmias (i.e., 2.0% nsVT, 0.7% sVT, and 1.6% VF). The occurrence of nsVT was associated with higher New York Heart Association (NYHA) functional class, whereas the incidence of sVT/VF was associated with acute myocardial infarction and ischemic heart disease. However, nsVT (25.0%; HR = 0.760; 95% CI 0.419-1.380; p = 0.367) and sVT/VF (28.8%; HR = 0.928; 95% CI 0.556-1.549; p = 0.776) were not associated with a higher risk of long-term all-cause mortality compared to patients with HFmrEF without ventricular tachyarrhythmias (31.5%). In-hospital cardiovascular mortality was more frequently observed in patients with HFmrEF and sVT/VF compared to those with HFmrEF but without sustained ventricular tachyarrhythmias (7.7% vs. 1.5%; p = 0.004). Finally, the risk of rehospitalization for worsening HF was not affected by the presence of ventricular tachyarrhythmias. Conclusions: The occurrence of ventricular tachyarrhythmias in patients hospitalized with HFmrEF was low and not associated with long-term prognosis.

Impacts of gene variants on drug effects-the foundation of genotype-guided pharmacologic therapy for long QT syndrome and short QT syndrome.

The clinical significance of optimal pharmacotherapy for inherited arrhythmias such as short QT syndrome (SQTS) and long QT syndrome (LQTS) has been increasingly recognised. The advancement of gene technology has opened up new possibilities for identifying genetic variations and investigating the pathophysiological roles and mechanisms of genetic arrhythmias. Numerous variants in various genes have been proven to be causative in genetic arrhythmias. Studies have demonstrated that the effectiveness of certain drugs is specific to the patient or genotype, indicating the important role of gene-variants in drug response. This review aims to summarize the reported data on the impact of different gene-variants on drug response in SQTS and LQTS, as well as discuss the potential mechanisms by which gene-variants alter drug response. These findings may provide valuable information for future studies on the influence of gene variants on drug efficacy and the development of genotype-guided or precision treatment for these diseases.

Prognostic value of mitral valve regurgitation in patients with heart failure with mildly reduced ejection fraction.

BACKGROUND: Although mitral valve regurgitation (MR) is a common valvular heart disease in patients with heart failure (HF), there is a paucity of data on the characterization and outcomes of patients with HF with mildly reduced ejection fraction (HFmrEF) and concomitant MR. METHODS: From 2016 to 2022, consecutive patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction from 41% to 49% and signs and/or symptoms of HF) were retrospectively included at one institution. Patients with MR were compared with patients without MR. Further risk stratification was performed according to MR severity and etiology (i.e., primary vs. secondary MR). The primary end point was all-cause mortality at 30 months (median follow-up), and the key secondary end point was hospitalization for worsening HF. RESULTS: Of 2181 patients hospitalized with HFmrEF, 59% presented with mild, 10% with moderate, and 2% with severe MR. MR was associated with increased all-cause mortality at 30 months (HR = 1.756; 95% CI 1.458-2.114; p = 0.001), with higher risk in more advanced stages. Furthermore, MR patients had higher risk of HF-related re-hospitalization at 30 months (HR = 1.560; 95% CI 1.172-2.076; p = 0.002). Even after multivariable adjustment, mild, moderate, and severe MR were still associated with all-cause mortality. Finally, the risk of all-cause mortality was lower in patients with secondary MR compared with patients with primary MR (HR = 0.592; 95% CI 0.366-0.956; p = 0.032). CONCLUSION: MR is common in HFmrEF and independently associated with higher risk of all-cause mortality and HF hospitalization.

Discriminating factors excluding patients from a catheter-based left atrial appendage closure and an outcome analysis of non-intervened and intervened patients.

Introduction: The catheter-based left atrial appendage closure (LAAC) has evolved as an alternative to oral anticoagulation (OAC) among non-valvular atrial fibrillation (AF) patients in whom long-term OAC is contraindicated. In daily practice, however, a sizeable number of patients who have been referred for an LAAC do not receive this intervention. This study aimed primarily to investigate the factors deterring the practice of an LAAC in referred AF patients, and secondarily to compare the complication rates of intervened patients with those who had refused the intervention within 1 year. Material and methods: This retrospective single-centre study includes 200 patients. After a thoroughly conducted clinical selection process, 161 of these patients (80.5%) were excluded from receiving an LAAC intervention. Results: An analysis comparing these patients to those receiving an LAAC reveales that a higher proportion of intervened patients had suffered a prior gastrointestinal bleeding (48.7 vs. 28.0%; p = 0.013) as well as a haemorrhagic stroke (12.8 vs. 2.5%; p = 0.015), and was not anticoagulated at the time of presentation (35.9 vs. 14.9%; p = 0.006). The main reason for not conducting the procedure was patient refusal (62.1%) followed by multimorbidity (16.8%). The annual rate of ischaemic strokes and bleedings among patients refusing the intervention was 2.1% and 29.5%, respectively, and this was not statistically different from the intervened patients (each p > 0.05). Conclusions: The reasons why patients did not undergo the catheter-based LAAC were mainly reluctance for the procedure and multimorbidity. Furthermore, it could be assumed that the potential benefit of the LAAC may not be realised within the first year.

Catecholamine induces endothelial dysfunction via Angiotensin II and intermediate conductance calcium activated potassium channel.

Endothelial dysfunction contributes to the pathogenesis of Takotsubo syndrome (TTS). However, the exact mechanism underlying endothelial dysfunction in the setting of TTS has not been completely clarified. This study aims to investigate the roles of angiotensin II (Ang II) and intermediate-conductance Ca2+-activated K+ (SK4) channels in catecholamine-induced endothelial dysfunction. Human cardiac microvascular endothelial cells (HCMECs) were exposed to 100 µM epinephrine (Epi), mimicking the setting of TTS. Epi treatment increased the ET-1 concentration and reduced NO levels in HCMECs. Importantly, the effects of Epi were found to be mitigated in the presence of Ang II receptor blockers. Furthermore, Ang II mimicked Epi effects on ET-1 and NO production. Additionally, Ang II inhibited tube formation and increased cell apoptosis. The effects of Ang II could be reversed by an SK4 activator NS309 and mimicked by an SK4 channel blocker TRAM-34. Ang II also inhibited the SK4 channel current (ISK4) without affecting its expression level. Ang II could depolarize the cell membrane potential. Ang II promoted ROS release and reduced protein kinase A (PKA) expression. A ROS blocker prevented Ang II effect on ISK4. The PKA activator Sp-8-Br-cAMPS increased SK4 channel currents. Epinephrine enhanced the activity of ACE by activating the α1 receptor/Gq/PKC signal pathway, thereby promoting the secretion of Ang II. The study suggested that high-level catecholamine can increase Ang II release from endothelial cells by α1 receptors/Gq/PKC signal pathway. Ang II can inhibit SK4 channel current by increasing ROS generation and reducing PKA expression, thereby contributing to endothelial dysfunction.