Metabolic activation of WHO-congeners PCB28, 52, and 101 by human CYP2A6: evidence from in vitro and in vivo experiments.

Despite extensive research on the metabolism of polychlorinated biphenyls (PCBs), knowledge gaps persist regarding their isoform-specific biotransformation pathways. This study aimed to elucidate the role of different cytochrome P450 enzymes in PCB metabolism, focusing on WHO-congeners 2,4,4'-trichlorobiphenyl (PCB28), 2,2',5,5'-tetrachlorobiphenyl (PCB52), and 2,2',4,5,5'-pentachlorobiphenyl (PCB101). Utilizing engineered HEK293 cell lines, we investigated the in vitro metabolism of these PCBs by CYP1A2, CYP2C8, CYP2C9, CYP3A4, CYP2A6, and CYP2E1, revealing robust production of hydroxylated metabolites. Our results show that CYP2A6 plays a major role in the metabolism of these congeners responsible for predominant formation of para-position hydroxylated metabolites, with concentrations reaching up to 1.61 µg/L (5,89 nM) for PCB28, 316.98 µg/L (1,03 µM) for PCB52, and 151.1 µg/L (441 nM) for PCB101 from a 20 µM parent PCB concentration. Moreover, concentration-dependent cytotoxic and cytostatic effects induced by reactive intermediates of the PCB hydroxylation pathway were observed in HEK293CYP2A6 cells, for all three congeners tested. CYP2A6 was specifically capable of activating PCBs 28 and 101 to genotoxic metabolites which produced genetic defects which were propagated to subsequent generations, potentially contributing to carcinogenesis. In a clinical study examining CYP2A6 enzyme activity in formerly exposed individuals with elevated internal PCB levels, a participant with increased enzyme activity showed a direct association between the phenotypic activity of CYP2A6 and the metabolism of PCB28, confirming the role of CYP2A6 in the in vivo metabolism of PCB28 also in humans. These results altogether reinforce the concept that CYP2A6 plays a pivotal role in PCB congener metabolism and suggest its significance in human health, particularly in the metabolism of lower chlorinated, volatile PCB congeners.

Impact of steroid hormone levels on estradiol-mediated regulation of cytochrome P450 2B6 compared to 1B1 in breast cancer cells.

Pharmacogenetic variants of the steroid hormone-metabolizing enzyme cytochrome P450 2B6 (CYP2B6) were reported to be associated with breast cancer (BC) risk and prognosis. CYP2B6 expression is inducible by estradiol (E2) but induction was demonstrated only under steroid hormone-deprived medium conditions. Physiological conditions, however, even under endocrinological BC treatment, do not correspond to complete steroid hormone depletion. The aim of this study was to investigate the E2-mediated CYP2B6 and CYP1B1 regulation under various steroid hormone conditions, including physiological concentrations, in human oestrogen receptor positive (T47D, MCF-7) and negative (MDA-MB-231) BC cell lines. We confirm that steroid-deprived pre-cultivation led to CYP2B6 upregulation in T47D, but not in MCF-7. However, when pre-cultivated with steroid-containing medium CYP2B6 was downregulated in T47D and MCF-7, while the addition of physiological E2 concentrations to steroid-deprived medium resulted in a downregulation in T47D. In contrast, CYP1B1 was never downregulated in any culture condition. Thus, we show that E2-mediated CYP2B6 regulation in BC cells depends on steroid hormone exposure in a cell line-specific manner. Our data indicates the importance of being careful with conclusions drawn from CYP2B6 induction findings in vitro, as we demonstrate potential influences of hormonal changes on CYP2B6 expression, which could impact steroid hormone homeostasis and, consequently, BC risk.

Prognostic value of non-invasive programmed ventricular stimulation after VT ablation to predict VT recurrences.

BACKGROUND: The prognostic value of (non)-invasive programmed ventricular stimulation (NIPS) to predict recurrences of ventricular tachycardia (VT) is under discussion. Optimal endpoints of VT ablation are not well defined, and optimal timepoint of NIPS is unknown. The goal of this study was to evaluate the ability of programmed ventricular stimulation at the end of the VT ablation procedure (PVS) and NIPS after VT ablation to identify patients at high risk for VT recurrence. METHODS: Between January 2016 and February 2022, consecutive patients with VT and structural heart disease undergoing first VT ablation and consecutive NIPS were included. In total, 138 patients were included. All patients underwent NIPS through their implanted ICDs after a median of 3 (1-5) days after ablation (at least 2 drive cycle lengths (500 and 400 ms) and up to four right ventricular extrastimuli until refractoriness). Clinical VT was defined by comparison with 12-lead electrocardiograms and stored ICD electrograms from spontaneous VT episodes. Patients were followed for a median of 37 (13-61) months. RESULTS: Of the 138 patients, 104 were non-inducible (75%), 27 were inducible for non-clinical VTs (20%), and 7 for clinical VT (5%). In 107 patients (78%), concordant results of PVS and NIPS were observed. After 37 ± 20 months, the recurrence rate for any ventricular arrhythmia was 40% (normal NIPS 29% vs. inducible VT during NIPS 66%; log-rank p = 0.001) and for clinical VT was 3% (normal NIPS 1% vs. inducible VT during NIPS 9%; log-rank p = 0.045). Positive predictive value (PPV) and negative predictive value (NPV) of NIPS were higher compared to PVS (PPV: 65% vs. 46% and NPV: 68% vs. 61%). NIPS revealed the highest NPV among patients with ICM and LVEF > 35%. Patients with inducible VT during NIPS had the highest VT recurrences and overall mortality. Patients with both negative PVS and NIPS had the lowest any VT recurrence rates with 32%. Early re-ablation of patients with recurrent VTs during index hospitalization was feasible but did not reveal better long-term VT-free survival. CONCLUSIONS: In patients after VT ablation and structural heart disease, NIPS is superior to post-ablation PVS to stratify the risk of VT recurrences. The PPV and NPV of NIPS at day 3 were superior compared to PVS at the end of the procedure to predict recurrent VT, especially in patients with ICM.

A screening for cerebral deoxygenation during VT ablations in patients with structural heart disease.

BACKGROUND: Patients undergoing ventricular tachycardia (VT) ablation often present with structural heart disease (SHD) and reduced ejection fraction. Inducing VT by programmed electrical stimulation (PES) puts these patients at risk for hemodynamic instability and cerebral hypoperfusion. OBJECTIVE: The present study screens for cerebral oxygen desaturation phases (ODPs) in patients undergoing VT ablation. METHODS: Forty-seven patients (age 61 ± 14 years, 72% males) underwent ablation of sustained VT with simultaneous neuromonitoring using near-infrared spectroscopy (NIRS). RESULTS: Analysis of NIRS signal identified ODPs in 29 patients (62%). ODPs were associated with a higher prevalence of ischemic heart disease (IHD) (45% vs. 11%, p = 0.024), previous VT episodes (n = 16 vs. 4, p = 0.018), and VTs inducible by PES (n = 2.4 vs. 1.2, p = 0.004). Patients with ODPs were more likely to be admitted to intensive care unit (ICU) (78% vs. 33%, p = 0.005) and had more in-hospital VT recurrences (24% vs. 0%, p = 0.034). No differences were observed in VT recurrence rates after hospital discharge (41.4% vs. 44.4%, p = 0.60) and left ventricular ejection fraction (34% vs. 38%, p = 0.567). IHD (OR: 32.837, p = 0.006), ICU admission (OR: 14.112, p = 0.013), and the number of VTs inducible at PES (OR: 2.705, p = 0.015) were independently associated with ODPs. CONCLUSIONS: This study registers episodes of cerebral hypoperfusion in 62% of patients undergoing VT ablation and identifies IHD and the number of VTs inducible at PES as possible risk factors for these episodes.

Submaximal, Low-Dose Eccentric vs Traditional Cycling Exercise: Reduced Oxygen Uptake and Pulmonary Artery Pressure Assessed by Echocardiography in Healthy Middle-aged Adults. A Randomized Controlled, Crossover Trial.

Objective: To investigate the ventilatory and circulatory differences between eccentric (ECC) and concentric (CON) cycling exercise at submaximal, low-dose intensity from onset to end-exercise in healthy middle-aged participants. Design: Randomized controlled crossover trial. Setting: The participants underwent 1 ECC and 1 CON test according to stepwise incremental exercise protocols at identical, submaximal intensities. Breath-by-breath analyses of ventilatory gas exchange and echocardiography were used to assess cardiopulmonary function during exercise. Participants: 24 healthy middle-aged, untrained participants (14 women, 10 men, 50±14 years) were included. Interventions: 1 ECC and 1 CON test at submaximal intensities. Main Outcome Measure: The main outcome was oxygen uptake (V'O2). Results: The V'O2 increase was reduced by -422 mL/min (-52%, 95% confidence interval: -513 to -292, P<.001) during ECC, as well as the ventilatory drive. Echocardiographic parameters, heart rate (-14%), cardiac output (-21%), stroke volume (-15%), and pulmonary artery pressure by tricuspid regurgitation pressure gradient (TRPG) (-26%) were also significantly reduced during ECC compared with CON at identical intensities. Participants reported significantly less dyspnea and unchanged perceived leg fatigue in ECC. Conclusion: ECC was well tolerated, and significant reductions were observed in V'O2, ventilation, and right ventricular load compared with CON, even at low intensity levels. This study, conducted on healthy middle-aged participants, did not raise concerns that would hinder further investigation of the effects of ECC in patients with severely limited cardiopulmonary disease, and it calls for further research on this topic.

Prognosis and treatment strategies for atrial fibrillation in heart failure with mildly reduced ejection fraction.

AIMS: The study investigates the prognosis of atrial fibrillation (AF) in patients with heart failure with mildly reduced ejection fraction (HFmrEF). Data concerning the prognostic impact of AF in patients with HFmrEF is scarce. METHODS AND RESULTS: Consecutive patients with HFmrEF [i.e. left ventricular ejection fraction 41-49% and signs and/or symptoms of heart failure (HF)] were retrospectively included at one institution from 2016 to 2022. Patients with AF were compared with patients without with regard to the primary composite endpoint of all-cause mortality and HF-related rehospitalization at 30 months (median follow-up). Statistical analyses included Kaplan-Meier, multivariable Cox proportional regression analyses, and propensity score matching. A total of 2148 patients with HFmrEF were included with an overall prevalence of AF of 43%. The presence of AF was associated with a higher risk of the primary composite endpoint all-cause mortality and HF-related rehospitalization at 30 months [hazard ratio (HR) = 2.068; 95% confidence interval (CI) 1.802-2.375; P = 0.01], which was confirmed after propensity score matching (HR = 1.494; 95% CI 1.216-1.835; P = 0.01). AF was an independent predictor of both all-cause mortality (HR = 1.340; 95% CI 1.066-1.685; P = 0.01) and HF-related rehospitalization (HR = 2.061; 95% CI 1.538-2.696; P = 0.01). Finally, rhythm control may be associated with lower risk of all-cause mortality compared with rate control for AF (HR = 0.342; 95% CI 0.199-0.587; P = 0.01). CONCLUSION: Atrial fibrillation affects 43% of patients with HFmrEF and represents an independent predictor of adverse long-term prognosis.

By now, limited data regarding the prognostic impact of comorbidities in heart failure with mildly reduced ejection fraction (HFmrEF) are available, contributing to the overall limited evidence regarding the treatment of patients with HFmrEF. The present study investigates the prognostic impact of the presence of atrial fibrillation (AF) on the long-term prognosis of patients with HFmrEF using a large retrospective study of 2148 patients hospitalized with HFmrEF from 2016 to 2022. Atrial fibrillation was prevalent in 43% of patients with HFmrEF and independently associated with an increased risk of the composite of long-term all-cause mortality and heart failure-related rehospitalization. Adverse prognosis in patients with concomitant AF was confirmed using multivariable Cox regression analyses and propensity score matching. Finally, the achievement of rhythm control may be associated with a lower risk of long-term all-cause mortality. Further studies are needed to demonstrate the effect of rhythm control and catheter ablation for AF in patients with HFmrEF.

Decrypting the molecular basis of cellular drug phenotypes by dose-resolved expression proteomics.

Proteomics is making important contributions to drug discovery, from target deconvolution to mechanism of action (MoA) elucidation and the identification of biomarkers of drug response. Here we introduce decryptE, a proteome-wide approach that measures the full dose-response characteristics of drug-induced protein expression changes that informs cellular drug MoA. Assaying 144 clinical drugs and research compounds against 8,000 proteins resulted in more than 1 million dose-response curves that can be interactively explored online in ProteomicsDB and a custom-built Shiny App. Analysis of the collective data provided molecular explanations for known phenotypic drug effects and uncovered new aspects of the MoA of human medicines. We found that histone deacetylase inhibitors potently and strongly down-regulated the T cell receptor complex resulting in impaired human T cell activation in vitro and ex vivo. This offers a rational explanation for the efficacy of histone deacetylase inhibitors in certain lymphomas and autoimmune diseases and explains their poor performance in treating solid tumors.

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.

Motivational Interviewing improves postoperative nutrition goals within the Enhanced Recovery after Surgery (ERAS®) pathway in elective bowel surgery - A randomized clinical pilot trial.

BACKGROUND & AIMS: Exploration whether Motivational Interviewing (MI) could be learned and implemented with ease within a surgical in-hospital setting and whether participation in the intervention led to significantly higher compliance with ERAS®-recommended protein intake goals. The individual healing process of many patients is delayed because they fail to cover their calorie requirement, which could be counteracted by a patient-centered conversational intervention that is new in perioperative practice. METHODS: This patient-blinded pilot-RCT included 60 patients (≥18 years) following the certified ERAS® bowel protocol for colorectal surgery between March and August 2022. Five perioperative MI interventions were conducted by two health employees certified to perform MI. Key endpoints were the number of protein shakes drunk, calories of proteins ingested and overall calorie intake. RESULTS: A total of 60 patients (34 men [56.7%]; mean [SD] age, 60.7 [13.3] years) were randomized. MI patient-group had significantly higher protein shake intake on all postoperative days except day 3. For days 0-3 MI group drank significantly more shakes overall (median 5.5 vs. 2.0; P = 0.004) and consumed more calories (median 1650.0 vs. 600.0 kcal; P = 0.004) and proteins (median 110.0 vs. 40.0 g; P = 0.005). Total calorie intake for each day by shakes and dietary intake was significantly higher in the MI-intervention group on day 2 (mean 1772.3 vs. 1358.9 kcal; P = 0.03). CONCLUSIONS: MI may contribute to improve compliance with nutritional goals in the certified ERAS® protocol by increasing protein and calorie intake. The findings suggest further investigation of MI to help patients achieve their perioperative nutrition goals in different clinical settings. TRIAL REGISTRATION: DRKS - Deutsches Register Klinischer Studien; DRKS-ID: DRKS00027863; https://drks.de/search/de/trial/DRKS00027863.

Influence of motivational interviewing on postoperative mobilization in the enhanced recovery after surgery (ERAS®) pathway in elective colorectal surgery - a randomized patient-blinded pilot study.

PURPOSE: Early mobilization is an essential component of the Enhanced Recovery after Surgery (ERAS®)-pathway. However, a large percentage of patients fail to achieve the ERAS® recommended goal (360 min out of bed from post-operative day 1/POD1). Motivational Interviewing (MI) is an evidence-based type of patient-centered consultation to promote intrinsic motivation. This study aims to evaluate if MI can improve postoperative mobilization. METHODS: This two-arm, patient-blinded pilot randomized controlled trial included ERAS®-patients undergoing elective bowel resections. Conversations were validated by MI Treatment Integrity. Two validated motion sensors (movisens) and self-assessments were used to measure mobilization (POD1-POD3: Time out of bed, time on feet and step count). RESULTS: 97 patients were screened, 60 finally included and randomized. Cumulatively across POD1-3, the intervention group (IG) was longer out of bed than the control group (CG) (median: 685 vs. 420 min; p=0.022). The IG achieved the ERAS®-goal of 360 min/day more frequently across POD1-3 (27.4% vs. 10.61%; p=0.013). Time on feet was 131.5 min/day (median per POD) in IG vs. 95.8 min/day in the CG (p=0.212), step count was 1347 in IG vs. 754 steps/day in CG (p=0.298). CONCLUSION: MI could be conducted low threshold and was well accepted by patients. MI can improve mobilization in the context of ERAS®. Despite better performance, it should be noted that only 27.4% of the IG reached the ERAS®-compliance goal of 360 min/day. The findings of this pilot study stipulate to further test the promising perioperative effects of MI within a multicenter superiority trial. REGISTRATION: This study was registered prospectively in the German Clinical Trials Register on 25.02.2022. Trial registration number is "DRKS00027863".

SARS-CoV-2 Transmission during High-Altitude Field Studies.

Grimm, Mirjam, Lucie Ziegler, Annina Seglias, Maamed Mademilov, Kamila Magdieva, Gulzada Mirzalieva, Aijan Taalaibekova, Simone Suter, Simon R. Schneider, Fiona Zoller, Vera Bissig, Lukas Reinhard, Meret Bauer, Julian Müller, Tanja L. Ulrich, Arcangelo F. Carta, Patrick R. Bader, Konstantinos Bitos, Aurelia E. Reiser, Benoit Champigneulle, Damira Ashyralieva, Philipp M. Scheiwiller, Silvia Ulrich, Talant M. Sooronbaev, Michael Furian, and Konrad E. Bloch. SARS-CoV-2 Transmission during High-Altitude Field Studies. High Alt Med Biol. 00:00-00, 2024. Background: Throughout the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, virus transmission during clinical research was of concern. Therefore, during high-altitude field studies performed in 2021, we took specific COVID-19 precautions and investigated the occurrence of SARS-CoV-2 infection. Methods: From May to September 2021, we performed studies in patients with chronic obstructive pulmonary disease (COPD) and in healthy school-age children in Kyrgyzstan in high-altitude facilities at 3,100 m and 3,250 m and at 760 m. The various implemented COVID-19 safety measures included systematic SARS-CoV-2 rapid antigen testing (RAT). Main outcomes were SARS-CoV-2-RAT-positive rate among participants and staff at initial presentation (prevalence) and SARS-CoV-2-RAT-positive conversion during and within 10 days after studies (incidence). Results: Among 338 participants and staff, SARS-CoV-2-RAT-positive prevalence was 15 (4.4%). During mean ± SD duration of individual study participation of 3.1 ± 1.0 day and within 10 days, RAT-positive conversion occurred in 1/237(0.4%) participants. Among staff working in studies for 31.5 ± 29.3 days, SARS-CoV-2-RAT-positive conversion was 11/101(10.9%). In all 338 individuals involved in the studies over the course of 15.6 weeks, the median SARS-CoV-2-RAT-positive incidence was 0.00%/week (quartiles 0.00; 0.64). Over the same period, the median background incidence among the total Kyrgyz population of 6,636 million was 0.06%/week (0.03; 0.11), p = 0.013 (Wilcoxon rank sum test). Conclusions: Taking precautions by implementing specific safety measures, SARS-CoV-2 transmission during clinical studies was very rare, and the SARS-CoV-2 incidence among participants and staff was lower than that in the general population during the same period. The results are reassuring and may help in decision-making on the conduct of clinical research in similar settings.

Simultaneous analysis of cannabinoids and terpenes in Cannabis sativa inflorescence using full comprehensive two-dimensional liquid chromatography coupled to smart active modulation.

Nowadays, the higher peak capacity achievable by comprehensive two-dimensional liquid chromatography (LC×LC) for the analysis of vegetal samples is well-recognized. In addition, numerous compounds may be present in very different amounts. Cannabinoids and terpenes represent the main components of Cannabis sativa inflorescence samples, whose quantities are relevant for many application purposes. The analyses of both families are performed by different methods, at least two different separation methodologies, mainly according to their chemical characteristics and concentration levels. In this work, concentration differences and sample complexity issues were addressed using an LC×LC method that incorporates an optimized modulation strategy, namely smart active modulation, for the simultaneous analysis of cannabinoids and terpenes. The system was built by interposing an active flow splitter pump between both dimensions. This set up aimed to exploit the known advantages of LC×LC. In addition, here we proposed to use the splitter pump for online control over the splitting ratio to facilitate the selective dilution of different eluted fractions containing compounds with highly different concentrations. This work represents the first application and demonstration of smart active modulation (SAM) in LC×LC to simultaneously determine analytes with significant differences in concentration levels present in complex samples. The proposed method was tested with eight different strains, from which fingerprints were taken, and numerous cannabinoids and terpenes were identified in these samples. With this strategy, between 49 and 54 peaks were obtained in the LC×LC chromatograms corresponding to different strains. THCA-A was the main component in six strains, while CBDA was the main component in the other two strains. The main terpenes found were myrcene (in five strains), limonene (in two strains), and humulene (in one strain). Additionally, numerous other cannabinoids and terpenes were identified in these samples, providing valuable compositional information for growers, as well as medical and recreational users. The SAM strategy here proposed is simple and it can be extended to other complex matrices.

Uncoupling of Cytochrome P450 2B6 and stimulation of reactive oxygen species production in pharmacogenomic alleles affected by interethnic variability.

Cytochrome P450 mediated substrate metabolism is generally characterized by the formation of reactive intermediates. In vitro and in vivo reaction uncoupling, results in the accumulation and dissociation of reactive intermediates, leading to increased ROS formation. The susceptibility towards uncoupling and altered metabolic activity is partly modulated by pharmacogenomic alleles resulting in amino acid substitutions. A large variability in the prevalence of these alleles has been demonstrated in CYP2B6, with some being predominantly unique to African populations. The aim of this study is to characterize the uncoupling potential of recombinant CYP2B6*1, CYP2B6*6 and CYP2B6*34 metabolism of specific substrates. Therefore, functional effects of these alterations on enzyme activity were determined by quantification of bupropion, efavirenz and ketamine biotransformation using HPLC-MS/MS. Determination of H2O2 levels was performed by the AmplexRed/horseradish peroxidase assay. Our studies of the amino acid substitutions Q172H, K262R and R487S revealed an exclusive use of the peroxide shunt for the metabolism of bupropion and ketamine by CYP2B6*K262R. Ketamine was also identified as a trigger for the peroxide shunt in CYP2B6*1 and all variants. Concurrently, ketamine acted as an uncoupler for all enzymes. We further showed that the expressed CYP2B6*34 allele results in the highest H2O2 formation. We therefore conclude that the reaction uncoupling and peroxide shunt are directly linked and can be substrate specifically induced with K262R carriers being most likely to use the peroxide shunt and R487S carrier being most prone to reaction uncoupling. This elucidates the functional diversity of pharmacogenomics in drug metabolism and safety.

Epicardial ventricular tachycardia ablation: safety and efficacy of access and ablation using low-iodine content.

BACKGROUND: Epicardial ablation has become an integral part of the treatment of ventricular tachycardias (VT). This study reports the safety of epicardial access as well as the efficacy of epicardial ablation of structural heart disease in a tertiary single-center experience. METHODS: Between January 2016 and February 2022, consecutive patients undergoing an epicardial access for VT ablation were included. Different puncture techniques and occurrence of epicardial access-related complications as well as the safety of ablation using non-ionic 5% dextrose in water (D5W) compared to standard 0.9% normal saline (NS) irrigation were analyzed. VT recurrence rates during a mean follow-up of 37 ± 23 months were reported. RESULTS: In total, 197 patients undergoing a total of 239 procedures were included (59.8 ± 15.3 years, 86% males). A total of 154 patients (78%) had non-ischemic cardiomyopathies with a mean LVEF of 37 ± 14. Anterior-oriented epicardial access was aimed for in all cases and was successful in 217 (91%) of all procedures, whereas access was achieved in 19 procedures (8%) only using an inferior oriented access and in three procedures (1%) using surgical access due to severe adhesions or anatomical requirements. Overall epicardial puncture-related complications occurred in 18 (8%) of all procedures with minor pericardial bleeding in nine, pericardial tamponade in one, pneumothorax in five, pneumopericardium in one, and abdominal puncture in two cases. Presence of adhesions could be identified as the only independent predictor of epicardial access-related complications. D5W was used in 79 cases and regular 0.9% saline in 117 procedures. No differences were seen regarding acute ablation success or complications. During follow-up, 47% of all patients were free from any VTs (56% D5W vs. 40% NS; log-rank p = 0.747) and 92% of clinical VTs (98% D5W vs. 91% NS; log-rank p = 0.139). CONCLUSIONS: In this large single-centre experience, epicardial access and ablation were safe and feasible. Although long-term clinical VT recurrence rates were low, overall VT recurrences as well as mortality were high advocating for a highly experienced, interdisciplinary approach including intense management of underlying cardiac disease/heart failure. Routine usage of D5W was safe and associated with comparable short- or long-term clinical or overall VT freedom.

The effect of high altitude (2500†m) on incremental cycling exercise in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: a randomised controlled crossover trial.

BACKGROUND: Our objective was to investigate the effect of a day-long exposure to high altitude on peak exercise capacity and safety in stable patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: In a randomised controlled crossover trial, stable patients with PAH or distal CTEPH without resting hypoxaemia at low altitude performed two incremental exercise tests to exhaustion: one after 3-5 h at high altitude (2500 m) and one at low altitude (470 m). RESULTS: In 27 patients with PAH/CTEPH (44% females, mean±sd age 62±14 years), maximal work rate was 110±64 W at 2500 m and 123±64 W at 470 m (-11%, 95% CI -16- -11%; p<0.001). Oxygen saturation measured by pulse oximetry and arterial oxygen tension at end-exercise were 83±6% versus 91±6% and 6.1±1.9 versus 8.6±1.9 kPa (-8% and -29%; both p<0.001) at 2500 versus 470 m, respectively. Maximal oxygen uptake was 17.8±7.5 L·min-1·kg-1 at high altitude versus 20±7.4 L·min-1·kg-1 at low altitude (-11%; p<0.001). At end-exercise, the ventilatory equivalent for carbon dioxide was 43±9 at 2500 m versus 39±9 at 470 m (9%, 95% CI 2-6%; p=0.002). No adverse events occurred during or after exercise. CONCLUSIONS: Among predominantly low-risk patients with stable PAH/CTEPH, cycling exercise during the first day at 2500 m was well tolerated, but peak exercise capacity, blood oxygenation and ventilatory efficiency were lower compared with 470 m.

Effects of 5-Week Oral Acetazolamide on Incremental Cycling Exercise in Pulmonary Arterial and Chronic Thromboembolic Pulmonary Hypertension: A Randomized Placebo-Controlled, Double-Blinded, Crossover Trial.

INTRODUCTION: Acetazolamide (AZA) improves nocturnal and daytime blood oxygenation in patients with pulmonary vascular disease (PVD), defined as pulmonary arterial and distal chronic thromboembolic pulmonary hypertension (CTEPH), and may improve exercise performance. METHODS: We investigated the effect of 5 weeks of AZA (250 mg bid) versus placebo on maximal load during incremental cycling ramp exercise in patients with PVD studied in a randomized controlled, double-blind, crossover design, separated by > 2 weeks of washout. RESULTS: Twenty-five patients (12 pulmonary arterial hypertension, 13 CTEPH, 40% women, age 62 ± 15 years) completed the trial according to the protocol. Maximum load was similar after 5 weeks of AZA versus placebo (113 ± 9 vs. 117 ± 9 watts [W]), mean difference -4 W (95% CI: -9 to 1, p = 0.138). With AZA, maximum (max)-exercise partial pressure of O2 (PaO2) was significantly higher by 1.1 kPa (95% CI: 0.5-1.8, p = 0.003), while arterial pH and partial pressure of CO2 were significantly lower. Gas exchange threshold was reached at a higher load with AZA (108 ± 8 W vs. 97 ± 8 W) and was therefore delayed by 11 W (95% CI: 3-19, p = 0.013), while the ventilatory equivalent for O2 and CO2 were significantly higher at both the max-exercise and gas exchange threshold with AZA versus placebo. CONCLUSION: AZA for 5 weeks did not significantly change maximum exercise capacity in patients with PVD despite a significant increase in PaO2. The beneficial effects of increased blood oxygenation may have been diminished by increased ventilation due to AZA-induced metabolic acidosis and increased dyspnea.

Illuminating phenotypic drug responses of sarcoma cells to kinase inhibitors by phosphoproteomics.

Kinase inhibitors (KIs) are important cancer drugs but often feature polypharmacology that is molecularly not understood. This disconnect is particularly apparent in cancer entities such as sarcomas for which the oncogenic drivers are often not clear. To investigate more systematically how the cellular proteotypes of sarcoma cells shape their response to molecularly targeted drugs, we profiled the proteomes and phosphoproteomes of 17 sarcoma cell lines and screened the same against 150 cancer drugs. The resulting 2550 phenotypic profiles revealed distinct drug responses and the cellular activity landscapes derived from deep (phospho)proteomes (9-10,000 proteins and 10-27,000 phosphorylation sites per cell line) enabled several lines of analysis. For instance, connecting the (phospho)proteomic data with drug responses revealed known and novel mechanisms of action (MoAs) of KIs and identified markers of drug sensitivity or resistance. All data is publicly accessible via an interactive web application that enables exploration of this rich molecular resource for a better understanding of active signalling pathways in sarcoma cells, identifying treatment response predictors and revealing novel MoA of clinical KIs.

Prognosis of cardiogenic shock with and without acute myocardial infarction: results from a prospective, monocentric registry.

OBJECTIVE: The study investigates the prognostic impact of cardiogenic shock (CS) stratified by the presence or absence of acute myocardial infarction (AMI). BACKGROUND: Intensive care unit (ICU) related mortality in CS patients remains unacceptably high despite improvement concerning the treatment of CS patients. METHODS: Consecutive patients with CS from 2019 to 2021 were included monocentrically. The prognostic impact of CS related to AMI was compared to patients without AMI-related CS. The primary endpoint was 30-day all-cause mortality. Statistical analyses included Kaplan-Meier analyses, multivariable Cox proportional regression analyses and propensity score matching. RESULTS: 273 CS patients were included (AMI-related CS: 49%; non-AMI-related CS: 51%). The risk of 30-day all-cause mortality was increased in patients with AMI-related CS (64% vs. 47%; HR = 1.653; 95% CI 1.199-2.281; p = 0.002), which was still observed after multivariable adjustment (HR = 1.696; 95% CI 1.153-2.494; p = 0.007). Even after propensity score matching (i.e., 87 matched pairs), AMI was still an independent predictor of 30-day mortality (HR = 1.524; 95% CI 1.020-2.276; p = 0.040). In contrast, non-ST-segment AMI (NSTEMI) and STEMI were associated with comparable prognosis (log-rank p = 0.528). CONCLUSION: AMI-related CS was associated with increased 30-day all-cause mortality compared to patients with CS not related to AMI. In contrast, the prognosis of STEMI- and NSTEMI-CS patients was comparable.

Oktoberfest: Open-source spectral library generation and rescoring pipeline based on Prosit.

Machine learning (ML) and deep learning (DL) models for peptide property prediction such as Prosit have enabled the creation of high quality in silico reference libraries. These libraries are used in various applications, ranging from data-independent acquisition (DIA) data analysis to data-driven rescoring of search engine results. Here, we present Oktoberfest, an open source Python package of our spectral library generation and rescoring pipeline originally only available online via ProteomicsDB. Oktoberfest is largely search engine agnostic and provides access to online peptide property predictions, promoting the adoption of state-of-the-art ML/DL models in proteomics analysis pipelines. We demonstrate its ability to reproduce and even improve our results from previously published rescoring analyses on two distinct use cases. Oktoberfest is freely available on GitHub (https://github.com/wilhelm-lab/oktoberfest) and can easily be installed locally through the cross-platform PyPI Python package.