Engineered coumarin accumulation reduces mycotoxin-induced oxidative stress and disease susceptibility.

Coumarins can fight pathogens and are thus promising for crop protection. Their biosynthesis, however, has not yet been engineered in crops. We tailored the constitutive accumulation of coumarins in transgenic Nicotiana benthamiana, Glycine max and Arabidopsis thaliana plants, as well as in Nicotiana tabacum BY-2 suspension cells. We did so by overexpressing A. thaliana feruloyl-CoA 6-hydroxylase 1 (AtF6'H1), encoding the key enzyme of scopoletin biosynthesis. Besides scopoletin and its glucoside scopolin, esculin at low level was the only other coumarin detected in transgenic cells. Mechanical damage of scopolin-accumulating tissue led to a swift release of scopoletin, presumably from the scopolin pool. High scopolin levels in A. thaliana roots coincided with reduced susceptibility to the root-parasitic nematode Heterodera schachtii. In addition, transgenic soybean plants were more tolerant to the soil-borne pathogenic fungus Fusarium virguliforme. Because mycotoxin-induced accumulation of reactive oxygen species and cell death were reduced in the AtF6'H1-overexpressors, the weaker sensitivity to F. virguliforme may be caused by attenuated oxidative damage of coumarin-hyperaccumulating cells. Together, engineered coumarin accumulation is promising for enhanced disease resilience of crops.

Mechanochemically Synthesised Flexible Electrodes Based on Bimetallic Metal-Organic Framework Glasses for the Oxygen Evolution Reaction.

The melting behaviour of metal-organic frameworks (MOFs) has aroused significant research interest in the areas of materials science, condensed matter physics and chemical engineering. This work first introduces a novel method to fabricate a bimetallic MOF glass, through melt-quenching of the cobalt-based zeolitic imidazolate framework (ZIF) [ZIF-62(Co)] with an adsorbed ferric coordination complex. The high-temperature chemically reactive ZIF-62(Co) liquid facilitates the formation of coordinative bonds between Fe and imidazolate ligands, incorporating Fe nodes into the framework after quenching. The resultant Co-Fe bimetallic MOF glass therefore shows a significantly enhanced oxygen evolution reaction performance. The novel bimetallic MOF glass, when combined with the facile and scalable mechanochemical synthesis technique for both discrete powders and surface coatings on flexible substrates, enables significant opportunities for catalytic device assembly.

Tailored Mobility in a Zeolite Imidazolate Framework (ZIF) Antibody Conjugate*.

Zeolitic imidazolate framework (ZIF) hybrid fluorescent nanoparticles and ZIF antibody conjugates have been synthesized, characterized, and employed in lateral-flow immunoassay (LFIA). The bright fluorescence of the conjugates and the possibility to tailor their mobility gives a huge potential for diagnostic assays. An enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase (HRP) as label, proved the integrity, stability, and dispersibility of the antibody conjugates, LC-MS/MS provided evidence that a covalent link was established between these metal-organic frameworks and lysine residues in IgG antibodies.

Observation of early ZIF-8 crystallization stages with X-ray absorption spectroscopy.

The present study investigates early stages of ZIF-8 crystallization up to 5 minutes post mixing of precursor solutions. Dispersive X-ray Absorption Spectroscopy (DXAS) provides a refined understanding of the evolution of the coordination environment during ZIF-8 crystallization. Linear Combination Analysis (LCA) suggests tetrakis(1-methylimidazole)zinc2+ to be a suitable and stable mononuclear structure analogue for some early stage ZIF-8 intermediates. Our results pave the way for more detailed studies on physico-chemical aspects of ZIF-8 crystallization to better control tailoring ZIF-8 materials for specific applications.

Health Care Utilization Following Inpatient Femoropopliteal Revascularization With Drug-Coated Balloon Angioplasty: A Nationwide Cohort Analysis.

PURPOSE: To examine nationwide variations in inpatient use of drug-coated balloons (DCBs) for treating femoropopliteal segment occlusive disease and whether DCBs are associated with reduced early out-of-hospital health care utilization. MATERIALS AND METHODS: The study included 24,022 patients who survived hospitalization for femoropopliteal revascularization using DCB angioplasty (n=7850) or uncoated balloon angioplasty (n=16,172) in the 2016-2017 Nationwide Readmissions Database. Differences in patient, hospitalization, and institutional characteristics were compared between treatment strategies. Adjusted logistic regression models were used to examine differences in 6-month rates of readmission, amputation, and repeat intervention. Results are presented as the odds ratio (OR) and 95% confidence interval (CI). RESULTS: Patients treated with DCBs had a higher prevalence of chronic limb-threatening ischemia, diabetes, hypertension, and tobacco use. Revascularization with a DCB was associated with shorter hospitalizations, lower median hospitalization costs, and fewer inpatient lower extremity amputations. Readmissions at 6 months were decreased in patients treated with DCBs compared with uncoated balloon angioplasty (OR 0.90, 95% CI 0.83 to 0.98, p=0.014). The most common reasons for readmission were complications related to procedures (15.4%) and diabetes (15.4%). Compared to patients treated with DCBs, patients treated with uncoated balloon angioplasty were more often readmitted with early procedure-related complications (13.3% vs 17.5%). There were no between-group differences in readmission for sepsis, myocardial infarction, or congestive heart failure. CONCLUSION: DCBs are less often used compared to uncoated balloons during inpatient femoropopliteal procedures. While DCB utilization is associated with more severe comorbidities and advanced peripheral artery disease, readmission rates are decreased through the first 6 months.

Pregnancy-associated arterial dissections: a nationwide cohort study.

AIMS: Pregnancy is a known risk factor for arterial dissection, which can result in significant morbidity and mortality in the peripartum period. However, little is known about the risk factors, timing, distribution, and outcomes of arterial dissections associated with pregnancy. METHODS AND RESULTS: We included all women ≥12 years of age with hospitalizations associated with pregnancy and/or delivery in the Nationwide Readmissions Database between 2010 and 2015. The primary outcome was any dissection during pregnancy, delivery, or the postpartum period (42-days post-delivery). Secondary outcomes included timing of dissection, location of dissection, and in-hospital mortality. Among 18 151  897 pregnant patients, 993 (0.005%) patients were diagnosed with a pregnancy-related dissection. Risk factors included older age (32.8 vs. 28.0 years), multiple gestation (3.6% vs. 1.9%), gestational diabetes (14.3% vs. 0.2%), gestational hypertension (6.0% vs. 0.6%), and pre-eclampsia/eclampsia (2.7% vs. 0.4%), in addition to traditional cardiovascular risk factors. Of the 993 patients with dissection, 150 (15.1%) dissections occurred in the antepartum period, 232 (23.4%) were diagnosed during the admission for delivery, and 611 (61.5%) were diagnosed in the postpartum period. The most common locations for dissections were coronary (38.2%), vertebral (22.9%), aortic (19.8%), and carotid (19.5%). In-hospital mortality was 3.7% among pregnant patients with a dissection vs. <0.001% in patients without a dissection. Deaths were isolated to patients with an aortic (8.6%), coronary (4.2%), or supra-aortic (<2.5%) dissection. CONCLUSION: Arterial dissections occurred in 5.5/100 000 hospitalized pregnant or postpartum women, most frequently in the postpartum period, and were associated with high mortality risk. The coronary arteries were most commonly involved. Pregnancy-related dissections were associated with traditional risk factors, as well as pregnancy-specific conditions.

The Arabidopsis non-host defence-associated coumarin scopoletin protects soybean from Asian soybean rust.

The fungus Phakopsora pachyrhizi (Pp) causes Asian soybean rust (SBR) disease which provokes tremendous losses in global soybean production. Pp is mainly controlled with synthetic fungicides to which the fungus swiftly develops fungicide resistance. To substitute or complement synthetic fungicides in Asian soybean rust control, we aimed to identify antifungal metabolites in Arabidopsis which is not a host for Pp. Comparative transcriptional and metabolic profiling of the Pp-inoculated Arabidopsis non-host and the soybean host revealed induction of phenylpropanoid metabolism-associated genes in both species but activation of scopoletin biosynthesis only in the resistant non-host. Scopoletin is a coumarin and an antioxidant. In vitro experiments disclosed fungistatic activity of scopoletin against Pp, associated with reduced accumulation of reactive oxygen species (ROS) in fungal pre-infection structures. Non-antioxidant and antioxidant molecules including coumarins with a similar structure to scopoletin were inactive or much less effective at inhibiting fungal accumulation of ROS and germination of Pp spores. When sprayed onto Arabidopsis leaves, scopoletin also suppressed the formation of Pp pre-infection structures and penetration of the plant. However, scopoletin neither directly activated defence nor did it prime Arabidopsis for enhanced defence, therefore emphasizing fungistatic activity as the exclusive mode of action of scopoletin against Pp. Because scopletin also protected soybean from Pp infection, the coumarin may serve as a natural fungicide or as a lead for the development of near-to-nature fungicides against Asian soybean rust.

Sex differences in presentation, management, and outcomes among patients hospitalized with acute pulmonary embolism.

While the presence of gender disparities in cardiovascular disease have been described, there is a paucity of data regarding the impact of sex in acute pulmonary embolism (PE). We identified all patients admitted to a tertiary care hospital with acute PE between August 1, 2012 through July 1, 2018. We stratified the presenting characteristics, management, and outcomes between women and men. Of the 2031 patients admitted with acute PE, 1081 (53.2%) were women. Women were more likely to present with dyspnea (59.8% vs 52.0%, p < 0.001) and less likely to present with hemoptysis (1.9% vs 4.0%, p = 0.01). Women were older (63.8 ± 17.4 years vs 62.3 ± 15.0 years, p = 0.04), but had lower rates of myocardial infarction, liver disease, smoking history, and prior DVT. PE severity was similar between women and men (massive: 4.9% vs 3.6%; submassive: 43.9% vs 41.8%; p = 0.19), yet women were more likely to present with normal right ventricular size on a surface echocardiogram (63.2% vs 54.8%, p = 0.01). In unadjusted analyses, women were less likely to survive to discharge (92.4% vs 94.7%, p = 0.04), but after adjustment, there was no sex-based survival difference. There were no sex differences in the PE-related diagnostic studies performed, use of advanced therapies, or short-term outcomes, before and after adjustment (p > 0.05 for all). In this large PE cohort from a tertiary care institution, women had different comorbidity profiles and PE presentations compared with men. Despite these differences, there were no sex disparities in PE management or outcomes.

An In Vitro Model of Angiogenesis during Wound Healing Provides Insights into the Complex Role of Cells and Factors in the Inflammatory and Proliferation Phase.

Successful vascularization is essential in wound healing, the histo-integration of biomaterials, and other aspects of regenerative medicine. We developed a functional in vitro assay to dissect the complex processes directing angiogenesis during wound healing, whereby vascular cell spheroids were induced to sprout in the presence of classically (M1) or alternatively (M2) activated macrophages. This simulated a microenvironment, in which sprouting cells were exposed to the inflammatory or proliferation phases of wound healing, respectively. We showed that M1 macrophages induced single-cell migration of endothelial cells and pericytes. In contrast, M2 macrophages augmented endothelial sprouting, suggesting that vascular cells infiltrate the wound bed during the inflammatory phase and extensive angiogenesis is initiated upon a switch to a predominance of M2. Interestingly, M1 and M2 shared a pro-angiogenic secretome, whereas pro-inflammatory cytokines were solely secreted by M1. These results suggested that acute inflammatory factors act as key inducers of vascular cell infiltration and as key negative regulators of angiogenesis, whereas pro-angiogenic factors are present throughout early wound healing. This points to inflammatory factors as key targets to modulate angiogenesis. The here-established wound healing assay represents a useful tool to investigate the effect of biomaterials and factors on angiogenesis during wound healing.

Cost-Effectiveness of Endovascular Stroke Therapy: A Patient Subgroup Analysis From a US Healthcare Perspective.

BACKGROUND AND PURPOSE: Endovascular therapy in addition to standard care (EVT+SC) has been demonstrated to be more effective than SC in acute ischemic large vessel occlusion stroke. Our aim was to determine the cost-effectiveness of EVT+SC depending on patients' initial National Institutes of Health Stroke Scale (NIHSS) score, time from symptom onset, Alberta Stroke Program Early CT Score (ASPECTS), and occlusion location. METHODS: A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALYs) associated with both strategies applied in a US setting. Model input parameters were obtained from the literature, including recently pooled outcome data of 5 randomized controlled trials (ESCAPE [Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke], EXTEND-IA [Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial], MR CLEAN [Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands], REVASCAT [Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within 8 Hours of Symptom Onset], and SWIFT PRIME [Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment]). Probabilistic sensitivity analysis was performed to estimate uncertainty of the model results. Net monetary benefits, incremental costs, incremental effectiveness, and incremental cost-effectiveness ratios were derived from the probabilistic sensitivity analysis. The willingness-to-pay was set to $50 000/QALY. RESULTS: Overall, EVT+SC was cost-effective compared with SC (incremental cost: $4938, incremental effectiveness: 1.59 QALYs, and incremental cost-effectiveness ratio: $3110/QALY) in 100% of simulations. In all patient subgroups, EVT+SC led to gained QALYs (range: 0.47-2.12), and mean incremental cost-effectiveness ratios were considered cost-effective. However, subgroups with ASPECTS ≤5 or with M2 occlusions showed considerably higher incremental cost-effectiveness ratios ($14 273/QALY and $28 812/QALY, respectively) and only reached suboptimal acceptability in the probabilistic sensitivity analysis (75.5% and 59.4%, respectively). All other subgroups had acceptability rates of 90% to 100%. CONCLUSIONS: EVT+SC is cost-effective in most subgroups. In patients with ASPECTS ≤5 or with M2 occlusions, cost-effectiveness remains uncertain based on current data.

Early CT perfusion mismatch in acute stroke is not time-dependent but relies on collateralization grade.

INTRODUCTION: Factors that determine the extent of the penumbra in the initial diagnostic workup using whole brain CT Perfusion (WB-CTP) remain unclear. The purpose of the current study was to determine a possible dependency of the initial mismatch size between cerebral blood flow (CBF) and cerebral blood volume (CBV) from time after symptom onset, leptomeningeal collateralization, and occlusion localization in acute middle cerebral artery (MCA) infarctions. METHODS: Out of an existing cohort of 992 consecutive patients receiving multiparametric CT scans including WB-CTP due to suspected stroke, we included patients who had (1) a witnessed time of symptom onset, (2) an infarction of the MCA territory as documented by follow-up imaging, and (3) an initial CBF volume of >10 ml. CBF and CBV lesion sizes, collateralization grade, and the site of occlusion were determined. RESULTS: We included 103 patients. Univariate analysis showed that time from symptom onset (168 +/- 91.2 min) did not correlate with relative or absolute mismatch volumes (p = 0.458 and p = 0.921). Higher collateralization gradings were associated with small absolute mismatch volumes (p = 0.004 and p < 0.001). Internal carotid artery (ICA) occlusions were associated with large absolute mismatch volumes (p = 0.004). Multivariate analysis confirmed that ICA occlusion was associated with large absolute mismatch volumes (p = 0.005), and high collateral grade was associated with small absolute mismatch volumes (p = 0.017). CONCLUSIONS: There is no significant correlation between initial CTP mismatch and time after symptom onset. Predictors of mismatch size include the extent of the collaterals and a proximal location of the occlusion.

Sourcing of an alternative pericyte-like cell type from peripheral blood in clinically relevant numbers for therapeutic angiogenic applications.

Autologous cells hold great potential for personalized cell therapy, reducing immunological and risk of infections. However, low cell counts at harvest with subsequently long expansion times with associated cell function loss currently impede the advancement of autologous cell therapy approaches. Here, we aimed to source clinically relevant numbers of proangiogenic cells from an easy accessible cell source, namely peripheral blood. Using macromolecular crowding (MMC) as a biotechnological platform, we derived a novel cell type from peripheral blood that is generated within 5 days in large numbers (10-40 million cells per 100 ml of blood). This blood-derived angiogenic cell (BDAC) type is of monocytic origin, but exhibits pericyte markers PDGFR-ß and NG2 and demonstrates strong angiogenic activity, hitherto ascribed only to MSC-like pericytes. Our findings suggest that BDACs represent an alternative pericyte-like cell population of hematopoietic origin that is involved in promoting early stages of microvasculature formation. As a proof of principle of BDAC efficacy in an ischemic disease model, BDAC injection rescued affected tissues in a murine hind limb ischemia model by accelerating and enhancing revascularization. Derived from a renewable tissue that is easy to collect, BDACs overcome current short-comings of autologous cell therapy, in particular for tissue repair strategies.

Different Imaging Strategies in Patients With Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis.

BACKGROUND AND PURPOSE: This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. METHODS: A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed tomographic angiography (CTA), magnetic resonance imaging, nonenhanced CT, or duplex ultrasound with intravenous (IV) thrombolysis being administered after positive findings. The analysis was performed from the societal perspective based on US recommendations. Input parameters were derived from the literature. Costs were obtained from United States costing sources and published literature. Outcomes were lifetime costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios, and net monetary benefits, with a willingness-to-pay threshold of $80,000 per QALY. The strategy with the highest net monetary benefit was considered the most cost-effective. Extensive deterministic and probabilistic sensitivity analyses were performed to explore the effect of varying parameter values. RESULTS: In the reference case analysis, CTA dominated all other imaging strategies. CTA yielded 0.02 QALYs more than magnetic resonance imaging and 0.04 QALYs more than duplex ultrasound followed by CTA. At a willingness-to-pay threshold of $80,000 per QALY, CTA yielded the highest net monetary benefits. The probability that CTA is cost-effective was 96% at a willingness-to-pay threshold of $80,000/QALY. Sensitivity analyses showed that duplex ultrasound was cost-effective only for a prior probability of ≤0.02 and that these results were only minimally influenced by duplex ultrasound sensitivity and specificity. Nonenhanced CT and magnetic resonance imaging never became the most cost-effective strategy. CONCLUSIONS: Our results suggest that CTA in patients with possible basilar artery occlusion is cost-effective.

Wavelet-based calculation of cerebral angiographic data from time-resolved CT perfusion acquisitions.

OBJECTIVES: To evaluate a new approach for reconstructing angiographic images by application of wavelet transforms on CT perfusion data. METHODS: Fifteen consecutive patients with suspected stroke were examined with a multi-detector CT acquiring 32 dynamic phases (∆t = 1.5s) of 99 slices (total slab thickness 99mm) at 80kV/200mAs. Thirty-five mL of iomeprol-350 was injected (flow rate = 4.5mL/s). Angiographic datasets were calculated after initial rigid-body motion correction using (a) temporally filtered maximum intensity projections (tMIP) and (b) the wavelet transform (Paul wavelet, order 1) of each voxel time course. The maximum of the wavelet-power-spectrum was defined as the angiographic signal intensity. The contrast-to-noise ratio (CNR) of 18 different vessel segments was quantified and two blinded readers rated the images qualitatively using 5pt Likert scales. RESULTS: The CNR for the wavelet angiography (501.8 ± 433.0) was significantly higher than for the tMIP approach (55.7 ± 29.7, Wilcoxon test p < 0.00001). Image quality was rated to be significantly higher (p < 0.001) for the wavelet angiography with median scores of 4/4 (reader 1/reader 2) than the tMIP (scores of 3/3). CONCLUSIONS: The proposed calculation approach for angiography data using temporal wavelet transforms of intracranial CT perfusion datasets provides higher vascular contrast and intrinsic removal of non-enhancing structures such as bone. KEY POINTS: • Angiographic images calculated with the proposed wavelet-based approach show significantly improved contrast-to-noise ratio. • CT perfusion-based wavelet angiography is an alternative method for vessel visualization. • Provides intrinsic removal of non-enhancing structures such as bone.

Validation of a method to differentiate arterial and venous vessels in CT perfusion data using linear combinations of quantitative time-density curve characteristics.

OBJECTIVES: We aimed to develop and evaluate a new method that reliably differentiates between cerebral arteries and veins using voxel-wise CT-perfusion-derived parameters. MATERIALS AND METHODS: Fourteen consecutive patients with suspected stroke but without pathological findings were examined on a multi-detector CT system: 32 dynamic phases (∆t = 1.5 s) during application of 35 mL iomeprol-350 were acquired at 80 kV/200mAs. Three hemodynamic parameters were calculated for 18 arterial and venous vessel segments: A (maximum of the time-density-curve), T (time-to-peak), and W (full-width-at-half-maximum). Using receiver operator characteristic (ROC) curve analysis and Fisher's linear discriminant analysis (FLDA), the performance of every classifier (A, T, W) and of all linear combinations for the differentiation of arterial and venous vessels was determined. RESULTS: A maximum area under the ROC-curve (AUC) of 0.945 (accuracy = 86.8%) was obtained using the FLDA combination of A&T or the triplet FLDA of A&T&W for the classification of venous and arterial vessels. The best single parameter was T with an AUC of 0.871 (accuracy = 79.0%), which performed significantly worse than the combination A&T (p < 0.001). CONCLUSIONS: Arteries and veins can be accurately differentiated based on dynamic CT perfusion data using the maximum of the time-density curve, its time-to-peak, its width, and FLDA combinations of these parameters, which yield accuracies up to 87%. KEY POINTS: • For classification of cerebral vasculature, time-to-peak has the best single-parameter accuracy. • Fisher's linear discriminant analysis improves the performance of the individual classifiers. • Combining signal maximum and time-to-peak parameters significantly increased the classifying potential. • Pre-processing of time-density-curves by Gaussian filtering or fitting can improve diagnostic accuracy.

Synthesis and photophysical properties of multichromophoric carbonyl-bridged triarylamines.

The synthesis and photophysical properties of two novel multichromophoric compounds is presented. Their molecular design comprises a carbonyl-bridged triarylamine core and either naphthalimides or 4-(5-hexyl-2,2'-bithiophene)naphthalimides as second chromophore in the periphery. The lateral chromophores are attached to the core via an amide linkage and a short alkyl spacer. The synthetic approach demonstrates a straightforward functionalization strategy for carbonyl-bridged triarylamines. Steady-state and time-resolved spectroscopic investigations of these compounds, in combination with three reference compounds, provide clear evidence for energy transfer in both multichromophoric compounds. The direction of the energy transfer depends on the lateral chromophore used. Furthermore, the compound bearing the lateral 4-(bithiophene)naphthaimides is capable of forming fluorescent gels at very low concentrations in the sub-millimolar regime whilst retaining its energy transfer properties.

Mitochondrial routing of glucose and sucrose polymers after pinocytotic uptake: avenues for drug delivery.

Mitochondria are key organelles organizing cellular metabolic flux. Therefore, a targeted drug delivery to mitochondria promises the advancement of medicine in fields that are associated with mitochondrial dysfunction. However, successful mitochondrial drug delivery is limited by complex transport steps across organelle membranes and fast drug efflux in cases of multidrug resistance. Strategies to deliver small-molecular-weight drugs to mitochondria are very limited, while the use of complex polymeric carriers is limited by a lack of clinical feasibility. We show here that clinically established macromolecules such as a sucrose copolymer (Ficoll 70/400 kDa) and polyglucose (dextran 70/500 kDa) are micropinocytosed swiftly by mesenchymal stem cells and subsequently routed to mitochondria. The intracellular level of Ficoll appears to decrease over time, suggesting that it does not persist within cells. After coupling to polysucrose, the low-molecular-weight photodynamic drug Rose Bengal reached mitochondria and thus exhibited an increased destructive potential after laser excitation. These findings support new opportunities to deliver already clinically approved drugs to mitochondria.

[New pacing strategies for heart failure]. / Neue Pacing-Strategien bei Herzinsuffizienz.

In patients with a reduced left ventricular (LV) systolic function (ejection fraction < 35%) and a left bundle branch block with a QRS duration > 130 ms, cardiac resynchronization therapy (CRT) can contribute to an improvement in the quality of life and a reduction in mortality. The resynchronization is mostly achieved by pacing via an epicardial LV lead in the coronary sinus; however, this approach is often limited by the patient's venous anatomy and an increase in the stimulation threshold over time. In addition, up to 30% of patients do not respond to the intervention. New treatment approaches involve direct stimulation of the conduction system by pacing of the bundle of His or left bundle branch. This enables a more physiological propagation of the stimulus. Pacing of the left bundle branch is achieved by advancing the lead into the right ventricle and screwing it deep into the interventricular septum. Due to the relatively large target area of the left bundle branch the success rate is very high (currently > 90%). Observational studies have shown a greater reduction in the QRS duration, a more pronounced improvement in systolic function and a lower hospitalization rate for heart failure associated with conduction system pacing compared to CRT using a coronary sinus lead. These findings have been confirmed in small randomized trials. Therefore, the use of left bundle branch pacing should be considered not only as a bail out in the case of failed resynchronization using coronary sinus lead placement but increasingly also as an initial pacing strategy. The results of the first large randomized trials are expected to be released in late 2024.