Switch between large hand-over-hand and small inchworm-like steps in myosin VI.

Many biological motor molecules move within cells using stepsizes predictable from their structures. Myosin VI, however, has much larger and more broadly distributed stepsizes than those predicted from its short lever arms. We explain the discrepancy by monitoring Qdots and gold nanoparticles attached to the myosin-VI motor domains using high-sensitivity nanoimaging. The large stepsizes were attributed to an extended and relatively rigid lever arm; their variability to two stepsizes, one large (72 nm) and one small (44 nm). These results suggest that there exist two tilt angles during myosin-VI stepping, which correspond to the pre- and postpowerstroke states and regulate the leading head. The large steps are consistent with the previously reported hand-over-hand mechanism, while the small steps follow an inchworm-like mechanism and increase in frequency with ADP. Switching between these two mechanisms in a strain-sensitive, ADP-dependent manner allows myosin VI to fulfill its multiple cellular tasks including vesicle transport and membrane anchoring.

Direct observation of stepping rotation of V-ATPase reveals rigid component in coupling between Vo and V1 motors.

V-ATPases are rotary motor proteins that convert the chemical energy of ATP into the electrochemical potential of ions across cell membranes. V-ATPases consist of two rotary motors, Vo and V1, and Enterococcus hirae V-ATPase (EhVoV1) actively transports Na+ in Vo (EhVo) by using torque generated by ATP hydrolysis in V1 (EhV1). Here, we observed ATP-driven stepping rotation of detergent-solubilized EhVoV1 wild-type, aE634A, and BR350K mutants under various Na+ and ATP concentrations ([Na+] and [ATP], respectively) by using a 40-nm gold nanoparticle as a low-load probe. When [Na+] was low and [ATP] was high, under the condition that only Na+ binding to EhVo is rate limiting, wild-type and aE634A exhibited 10 pausing positions reflecting 10-fold symmetry of the EhVo rotor and almost no backward steps. Duration time before the forward steps was inversely proportional to [Na+], confirming that Na+ binding triggers the steps. When both [ATP] and [Na+] were low, under the condition that both Na+ and ATP bindings are rate limiting, aE634A exhibited 13 pausing positions reflecting 10- and 3-fold symmetries of EhVo and EhV1, respectively. The distribution of duration time before the forward step was fitted well by the sum of two exponential decay functions with distinct time constants. Furthermore, occasional backward steps smaller than 36° were observed. Small backward steps were also observed during three long ATP cleavage pauses of BR350K. These results indicate that EhVo and EhV1 do not share pausing positions, Na+ and ATP bindings occur at different angles, and the coupling between EhVo and EhV1 has a rigid component.

Synthesis and Characterization of Ionic Li+ @C70 Endohedral Fullerene.

Ion-endohedral-fullerene has attracted growing interest due to the unique electronic and structural characteristics arising from its distinctive ionic nature. Although there has been only one reported ion-encapsulated fullerene, Li+ @C60 , a significant number of fundamental and applied studies have been conducted, making a substantial impact not only in chemistry and physics but also across various interdisciplinary research fields. Nevertheless, studies on ion-endohedral fullerenes are still in their infancy due to the limitations in variety, and hence, it remains an open question how the size and symmetry of fullerene, as well as the motion and position of the encapsulated ion, affect their physical/chemical properties. Herein, we report the synthesis of lithium-ion-endohedral [70]fullerene (Li+ @C70 X- , X=PF6 - and TFSI- ), a novel ionic endohedral fullerene. X-ray crystallography confirmed the encapsulation of Li+ by C70 cage as well as its ion-pair structure stabilized by external TFSI- counter anion. The encapsulated Li+ drastically lowered the orbital energy of the C70 cage by Coulomb interactions but did not affect the orbital energy gap and degeneracy. DFT studies were also performed, which supported the experimentally observed electronic effects caused by the encapsulated Li+ .

Comparative Data of Procedural and Midterm Outcomes in Patients Who Underwent Percutaneous Left Atrial Appendage Closure Between the WATCHMAN FLX and WATCHMAN 2.5 Devices　- Insight From the OCEAN-LAAC Registry.

BACKGROUND: Limited data are available regarding clinical outcomes after percutaneous left atrial appendage closure using WATCHMAN FLX (WM-FLX) and WATCHMAN-2.5 (WM2.5) devices in Asian patients.Methods and Results: Data of 1,464 consecutive patients (WM-FLX, n=909; WM2.5, n=555) were extracted from a Japanese multicenter registry, and clinical data were compared between the 2 groups. No in-hospital deaths, periprocedural stroke, or device embolization occurred. Procedural success was significantly higher in the WM-FLX than WM2.5 group (95.8% vs. 91.9%; P=0.002) owing to the lower incidence of periprocedural pericardial effusion (0.55% vs. 1.8%; P=0.021). No significant differences in all-cause death, postprocedural stroke, and device-related thrombus were observed between the 2 groups. However, the cumulative bleeding rate at 1 year was substantially lower in the WM-FLX group (7.8% vs. 16.4%; P<0.001). Landmark analysis of bleeding events highlighted lower bleeding rates in the WM-FLX than WM2.5 group within the first 6 months (6.4% vs. 14.8%; P<0.001), with comparable bleeding rates over the 6- to 12-month period (1.5% vs. 3.2%, respectively; P=0.065). CONCLUSIONS: This study demonstrated higher early safety and lower 1-year bleeding rates in the WM-FLX than WM2.5 group. The lower bleeding events with WM-FLX are likely due to multiple factors other than purely difference in devices, such as postprocedural drug regimen.

Impella support for refractory cardiogenic shock accompanied by diabetic ketoacidosis: a case report.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are strongly recommended in patients with heart failure, regardless of the presence of diabetes mellitus. A 74 year-old woman with a reduced left ventricular ejection fraction and diabetes mellitus (the types were unknown), receiving insulin and SGLT2 inhibitor, was hospitalized for altered consciousness with systemic hypotension. Upon admission, she was diagnosed with cardiogenic shock due to diabetic ketoacidosis. Intensive fluid resuscitation under Impella CP support successively improved her metabolic acidosis, preventing worsening pulmonary congestion by mechanically unloading the heart. After hemodynamic stabilization, she was diagnosed with type 1 diabetes mellitus for the first time. She was discharged on day 54 and was followed for 6 months without any recurrences. We must remain vigilant regarding the risk of diabetic ketoacidosis in patients using SGLT2 inhibitors, particularly those on insulin therapy or with diabetes mellitus of unknown types. Impella device shows promise as a circulatory support system in alleviating the left ventricle's workload and averting exacerbated pulmonary congestion, especially in cases where patients necessitate aggressive fluid replacement therapy, such as in the treatment of diabetic ketoacidosis concurrent with compromised cardiac function.

Label-Free Liquid Chromatography-Mass Spectrometry Quantitation of Relative N- and O-Glycan Concentrations in Human Milk in Japan.

Human milk is abundant in carbohydrates and includes human milk oligosaccharides (HMOs) and N/O-glycans conjugated to proteins. HMO compositions and concentrations vary in individuals according to the maternal secretor status based on the fucosyltransferase 2 genotype; however, the profile of N/O-glycans remains uninvestigated because of the analytical complexity. Herein, we applied a label-free chromatography-mass spectrometry (LC-MS) technique to elucidate the variation in the composition and concentration of N/O-glycans in human milk. We used label-free LC-MS to relatively quantify 16 N-glycans and 12 O-glycans in 200 samples of Japanese human milk (1-2 months postpartum) and applied high performance anion exchange chromatography with pulsed amperometric detection to absolutely quantify the concentrations of 11 representative HMOs. Cluster analysis of the quantitative data revealed that O-glycans and several HMOs were classified according to the presence or absence of fucose linked to galactose while N-glycans were classified into a different group from O-glycans and HMOs. O-glycans and HMOs with fucose linked to galactose were more abundant in human milk from secretor mothers than from nonsecretor mothers. Thus, secretor status influenced the composition and concentration of HMOs and O-glycans but not those of N-glycans in human milk.

Enhanced reactivity of Li+@C60 toward thermal [2 + 2] cycloaddition by encapsulated Li+ Lewis acid.

Lithium ion-endohedral fullerene (Li+@C60), a member of the burgeoning family of ion-endohedral fullerenes, holds substantial promise for diverse applications owing to its distinctive ionic properties. Despite the high demand for precise property tuning through chemical modification, there have been only a few reports detailing synthetic protocols for the derivatization of this novel material. In this study, we report the synthesis of Li+@C60 derivatives via the thermal [2 + 2] cycloaddition reaction of styrene derivatives, achieving significantly higher yields of monofunctionalized Li+@C60 compared to previously reported reactions. Furthermore, by combining experimental and theoretical approaches, we clarified the range of applicable substrates for the thermal [2 + 2] cycloaddition of Li+@C60, highlighting the expanded scope of this straightforward and selective functionalization method.

Direct identification of the rotary angle of ATP cleavage in F1-ATPase from Bacillus PS3.

F1-ATPase is the world's smallest biological rotary motor driven by ATP hydrolysis at three catalytic ß subunits. The 120° rotational step of the central shaft γ consists of 80° substep driven by ATP binding and a subsequent 40° substep. In order to correlate timing of ATP cleavage at a specific catalytic site with a rotary angle, we designed a new F1-ATPase (F1) from thermophilic Bacillus PS3 carrying ß(E190D/F414E/F420E) mutations, which cause extremely slow rates of both ATP cleavage and ATP binding. We produced an F1 molecule that consists of one mutant ß and two wild-type ßs (hybrid F1). As a result, the new hybrid F1 showed two pausing angles that are separated by 200°. They are attributable to two slowed reaction steps in the mutated ß, thus providing the direct evidence that ATP cleavage occurs at 200° rather than 80° subsequent to ATP binding at 0°. This scenario resolves the long-standing unclarified issue in the chemomechanical coupling scheme and gives insights into the mechanism of driving unidirectional rotation.

Genetic Perturbation Alters Functional Substates in Alkaline Phosphatase.

Enzymes inherently exhibit molecule-to-molecule heterogeneity in their conformational and functional states, which is considered to be a key to the evolution of new functions. Single-molecule enzyme assays enable us to directly observe such multiple functional states or functional substates. Here, we quantitatively analyzed functional substates in the wild-type and 69 single-point mutants of Escherichia coli alkaline phosphatase by employing a high-throughput single-molecule assay with a femtoliter reactor array device. Interestingly, many mutant enzymes exhibited significantly heterogeneous functional substates with various types, while the wild-type enzyme showed a highly homogeneous substate. We identified a correlation between the degree of functional substates and the level of improvement in promiscuous activities. Our work provides much comprehensive evidence that the functional substates can be easily altered by mutations, and the evolution toward a new catalytic activity may involve the modulation of the functional substates.

Prognostic impact of remote dielectric sensing value following TAVR.

Remote dielectric sensing (ReDS) system non-invasively quantifies pulmonary congestion. Re-admission following trans-catheter aortic valve replacement (TAVR) remains an unsolved matter. Residual pulmonary congestion is a strong risk factor of worse clinical outcomes in patients with heart failure. ReDS system may have a prognostic impact in patients undergoing TAVR. Patients who received TAVR and ReDS measurements during index hospitalization between 2021 and 2022 were included. The prognostic impact of ReDS value on the composite endpoint of death or re-admission following index discharge was investigated. Totally, 42 patients (median 84 years, 14 men) were included. Median ReDS value at index discharge was 27% (24%, 30%) and 10 patients had ReDS values > 30%. During a median of 316 (282, 354) days following index discharge, a higher ReDS value at baseline was independently associated with the incidence of composite endpoint with an adjusted hazard ratio of 1.32 (95% confidence interval between 1.10 and 1.58) with a calculated cutoff of 30%, which significantly stratified the cumulative incidence of the composite endpoint (78% in the high ReDS group [N = 10] and 36% in the normal ReDS group [N = 32], p = 0.002). ReDS technology may be a promising tool to predict future clinical outcomes following TAVR by quantifying residual pulmonary congestion. The clinical implication of ReDS-guided aggressive intervention following TAVR remains the next concern.

Impact of the elevated angiopoietin-2 levels during Impella support on the short-term prognosis.

Elevated serum angiopoietin-2 levels in patients with acute myocardial infarction-related cardiogenic shock with and without intra-aortic balloon pump as well as acute decompensated heart failure are associated with short-term mortality. However, its prognostic impact in patients with cardiogenic shock supported by Impella-incorporated mechanical circulatory support (MCS) remains unknown. Patients who received temporary MCS (Impella alone or Impella and veno-arterial extracorporeal membrane oxygenation) in our institute between August 2018 and January 2022 were included in this prospective study. The serum levels of angiopoietin-2 were measured just before and following the initiation of temporary MCS therapy. Association between the levels of serum angiopoietin-2 and 30-day mortality was investigated. A total of 38 patients (median 72 years old, 63% men) were included. The median levels of serum angiopoetin-2 tended to decrease from baseline to 4 days following the initiation of temporary MCS from 5.2 (3.3, 10.5) ng/mL to 4.8 (2.7, 6.8) ng/mL (p = 0.132). A higher angiopoietin-2 (> 6.8 ng/mL) following the initiation of temporary MCS was associated with higher 30-day mortality (89.7% versus 44.4%, p = 0.0048) with an odds ratio 18.946 (95% confidence interval 1.624-218.695, p = 0.018) adjusted for potential confounders. A higher serum angiopoietin-2 level following the initiation of Impella-incorporated temporary MCS, instead of baseline angiopoetin-2 level, was associated with higher short-term mortality.

Rotary catalysis of bovine mitochondrial F1-ATPase studied by single-molecule experiments.

The reaction scheme of rotary catalysis and the torque generation mechanism of bovine mitochondrial F1 (bMF1) were studied in single-molecule experiments. Under ATP-saturated concentrations, high-speed imaging of a single 40-nm gold bead attached to the γ subunit of bMF1 showed 2 types of intervening pauses during the rotation that were discriminated by short dwell and long dwell. Using ATPγS as a slowly hydrolyzing ATP derivative as well as using a functional mutant ßE188D with slowed ATP hydrolysis, the 2 pausing events were distinctively identified. Buffer-exchange experiments with a nonhydrolyzable analog (AMP-PNP) revealed that the long dwell corresponds to the catalytic dwell, that is, the waiting state for hydrolysis, while it remains elusive which catalytic state short pause represents. The angular position of catalytic dwell was determined to be at +80° from the ATP-binding angle, mostly consistent with other F1s. The position of short dwell was found at 50 to 60° from catalytic dwell, that is, +10 to 20° from the ATP-binding angle. This is a distinct difference from human mitochondrial F1, which also shows intervening dwell that probably corresponds to the short dwell of bMF1, at +65° from the binding pause. Furthermore, we conducted "stall-and-release" experiments with magnetic tweezers to reveal how the binding affinity and hydrolysis equilibrium are modulated by the γ rotation. Similar to thermophilic F1, bMF1 showed a strong exponential increase in ATP affinity, while the hydrolysis equilibrium did not change significantly. This indicates that the ATP binding process generates larger torque than the hydrolysis process.

The 3 × 120° rotary mechanism of Paracoccus denitrificans F1-ATPase is different from that of the bacterial and mitochondrial F1-ATPases.

The rotation of Paracoccus denitrificans F1-ATPase (PdF1) was studied using single-molecule microscopy. At all concentrations of adenosine triphosphate (ATP) or a slowly hydrolyzable ATP analog (ATPγS), above or below Km, PdF1 showed three dwells per turn, each separated by 120°. Analysis of dwell time between steps showed that PdF1 executes binding, hydrolysis, and probably product release at the same dwell. The comparison of ATP binding and catalytic pauses in single PdF1 molecules suggested that PdF1 executes both elementary events at the same rotary position. This point was confirmed in an inhibition experiment with a nonhydrolyzable ATP analog (AMP-PNP). Rotation assays in the presence of adenosine diphosphate (ADP) or inorganic phosphate at physiological concentrations did not reveal any obvious substeps. Although the possibility of the existence of substeps remains, all of the datasets show that PdF1 is principally a three-stepping motor similar to bacterial vacuolar (V1)-ATPase from Thermus thermophilus This contrasts with all other known F1-ATPases that show six or nine dwells per turn, conducting ATP binding and hydrolysis at different dwells. Pauses by persistent Mg-ADP inhibition or the inhibitory ζ-subunit were also found at the same angular position of the rotation dwell, supporting the simplified chemomechanical scheme of PdF1 Comprehensive analysis of rotary catalysis of F1 from different species, including PdF1, suggests a clear trend in the correlation between the numbers of rotary steps of F1 and Fo domains of F-ATP synthase. F1 motors with more distinctive steps are coupled with proton-conducting Fo rings with fewer proteolipid subunits, giving insight into the design principle the F1Fo of ATP synthase.

Prognostic Implication of Small Dense LDL-Cholesterol Levels following Acute Coronary Syndrome.

Background and Objectives: Small dense LDL cholesterol is a strong risk factor for atherosclerosis. However, few studies have investigated the impacts of this specific lipid profile on the incident risk of adverse cardiovascular events in patients with acute coronary syndrome. Materials and Methods: Patients with acute coronary syndrome, who underwent revascularization, were included and followed for 2 years. The levels of small dense LDL cholesterol were measured at index discharge (day 0) in the setting of newly administered therapies for secondary prevention, including aspirin and statins, during the index hospitalization. The prognostic impact of small dense LDL-cholesterol levels on the risk of a primary composite endpoint, including cardiac death, non-fatal myocardial infarction, unstable angina pectoris, stroke, and heart failure, was investigated. Results: In total, 46 patients (median 75 (59, 83) years old, 63% men) were included. Median small dense LDL cholesterol was 19.4 (13.5, 23.8) mg/dL at index discharge. All patients initiated statin treatment before the index discharge, with a median LDL-cholesterol level of 77 (64, 109) mg/dL. Small dense LDL-cholesterol level was independently associated with an incremental risk for the primary endpoint (p < 0.05 by adjusting for several potential risk factors, including LDL cholesterol) with a cutoff of 32.6 mg/dL. Conclusions: Small dense LDL-cholesterol level was a significant risk factor for cardiovascular events following presentations of acute coronary syndrome.

Sex-Related Differences in Short-Term Prognosis in Patients with Acute Myocardial Infarction-Related Cardiogenic Shock Receiving Impella Support in Japan: From the J-PVAD Registry.

Background and Objectives: Sex-specific outcome in patients with acute myocardial infarction-related cardiogenic shock (AMI-CS) receiving temporary mechanical circulatory support remains controversial. Materials and Methods: Patients with AMI-CS who received Impella support were prospectively enrolled in the Japanese registry for Percutaneous Ventricular Assist Device. Patients enrolled between January 2021 and December 2022 were considered to be eligible. Patients with out-of-hospital cardiac arrest and those without revascularization were excluded. The sex disparity in the 30-day survival after the initiation of Impella support was evaluated. Results: A total of 924 patients (median age 73 years; 21% female) were included. Female patients were older and had a smaller physiques than male patients (p < 0.05 for both). Female sex was significantly associated with a higher 30-day mortality after adjustment for four other potential confounders with a hazard ratio of 1.365 (95% confidence interval 1.026-1.816, p = 0.0324). In the female cohort, patients who received Impella prior to revascularization (N = 138) had a greater survival rate compared to those who received Impella after revascularization (68.1% versus 44.8%, p = 0.0015). Conclusions: Among the patients with AMI-CS who received Impella support and underwent revascularization, female sex was independently associated with a lower 30-day survival. For female patients, early initiation of Impella support prior to revascularization may improve their clinical outcomes.

Structural Elements Involved in ATP Hydrolysis Inhibition and ATP Synthesis of Tuberculosis and Nontuberculous Mycobacterial F-ATP Synthase Decipher New Targets for Inhibitors.

The F1FO-ATP synthase is required for the viability of tuberculosis (TB) and nontuberculous mycobacteria (NTM) and has been validated as a drug target. Here, we present the cryo-EM structures of the Mycobacterium smegmatis F1-ATPase and the F1FO-ATP synthase with different nucleotide occupation within the catalytic sites and visualize critical elements for latent ATP hydrolysis and efficient ATP synthesis. Mutational studies reveal that the extended C-terminal domain (αCTD) of subunit α is the main element for the self-inhibition mechanism of ATP hydrolysis for TB and NTM bacteria. Rotational studies indicate that the transition between the inhibition state by the αCTD and the active state is a rapid process. We demonstrate that the unique mycobacterial γ-loop and subunit δ are critical elements required for ATP formation. The data underline that these mycobacterium-specific elements of α, γ, and δ are attractive targets, providing a platform for the discovery of species-specific inhibitors.

Decoupling Between Pulmonary Artery Diastolic and Wedge Pressure Following Transcatheter Aortic Valve Replacement.

BACKGROUND: Coexistent pulmonary hypertension with severe aortic stenosis confers a greater risk of mortality for patients undergoing transcatheter aortic valve replacement (TAVR). In this patient population, the impact of significant decoupling between pulmonary artery diastolic and pulmonary capillary wedge, as it relates to clinical risk, remained uncertain.Methods and Results:Patients with severe aortic stenosis who underwent TAVR and completed pre-procedural and post-procedural invasive hemodynamic assessments with right heart catheterization were retrospectively assessed. The impact of post-TAVR decoupling, defined as a pressure difference ≥3 mmHg, on 2-year all-cause mortality or risk of heart failure admission was analyzed. Among 77 included patients (median age 86 years, 23 men), 16 had post-TAVR decoupling. The existence of post-TAVR decoupling was associated with a higher cumulative incidence of the primary endpoint (44% vs. 7%, P=0.001), with an adjusted hazard ratio of 5.87 (95% confidence interval 1.58-21.9, P=0.008). CONCLUSIONS: A greater risk of worse outcomes in those with post-TAVR decoupling was observed. A therapeutic strategy for post-TAVR decoupling and its clinical implication need to be created and investigated in the future.

Edoxaban vs. Vitamin K Antagonist for Atrial Fibrillation After Transcatheter Aortic Valve Replacement in Japanese Patients　- A Subanalysis of the ENVISAGE-TAVI AF Trial.

BACKGROUND: Japanese patients undergoing transcatheter aortic valve replacement (TAVR) are often female and have a small body size, potentially impacting bleeding risk with antithrombotic therapy. Outcomes of direct oral anticoagulant use in these patients with atrial fibrillation (AF) need to be clarified.Methods and Results: This prespecified analysis included Japanese patients from ENVISAGE-TAVI AF, a prospective, randomized, open-label, adjudicator-masked trial that compared treatment with edoxaban and vitamin K antagonists (VKAs) in patients with AF after TAVR. The primary efficacy and safety outcomes were net adverse clinical events (NACE; composite of all-cause death, myocardial infarction, ischemic stroke, systemic embolic event, valve thrombosis, and International Society on Thrombosis and Haemostasis [ISTH]-defined major bleeding) and ISTH-defined major bleeding, respectively. Intention-to-treat (ITT) and on-treatment analyses were performed. Overall, 159 Japanese patients were enrolled (edoxaban group: 82, VKA group: 77) and followed for on average 483 days. Mean patient age was 83.8 years; 52.2% were female. In the ITT analysis, NACE rates were 10.9%/year with edoxaban and 12.5%/year with VKA (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.38-1.90); major bleeding occurred in 8.9%/year and 7.3%/year, respectively (HR, 1.17; 95% CI, 0.45-3.05). In edoxaban- and VKA-treated patients, rates of ischemic stroke were 1.8%/year and 1.0%/year, respectively; fatal bleeding rates were 0.9%/year and 2.0 %/year. On-treatment results were similar to ITT. CONCLUSIONS: In Japanese patients with AF after successful TAVR, edoxaban and VKA treatment have similar safety and efficacy profiles.

Impact of the whole activated clotting time during Impella support on short-term prognosis.

Impella (Abiomed, Danvers, MA, USA) is a percutaneous trans-catheter left ventricular assist device. Anticoagulant therapy targeting whole activated clotting time (ACT) between 160 and 180 s is recommended to prevent pump thrombosis during support. However, we sometimes experience fatal bleeding despite achieving the target ACT range. Consecutive patients who received Impella support in our institute between March 2018 and October 2020 were included in this retrospective study. The association between the averaged ACT levels during the Impella support and 30-day mortality was investigated. A total of 36 patients (71 years old, 61% males) were included. Most of the patients were managed within the recommended therapeutic range of ACT, and the average ACT level was 162 s. The higher ACT group (> 168 s) had older age, smaller body mass index, and higher serum creatinine compared with the lower ACT group (p < 0.05 for all). A higher ACT level was an independent risk factor of 30-day mortality with an adjusted hazard ratio of 1.085 (95% confidence interval 1.037-1.154) with a cut-off level of 168 s. There were only two thromboembolic events. Patients managed with higher ACT levels had a higher risk of 30-day mortality during Impella support. A low-dose heparin purge solution might be recommended in patients with high-risk for bleeding events.

Transcatheter closure of patent foramen ovale accompanying right-to-left shunt during Impella support.

We experienced a 65-year-old woman who was diagnosed as fulminant myocarditis and transferred on mechanical ventilator and veno-arterial extracorporeal membrane oxygenation (ECMO) supports. Impella 5.0 support was additionally initiated to improve pulmonary edema and unload left ventricle. We found a patent foramen ovale (PFO) at the time of Impella insertion by transesophageal echocardiography. Follow-up transesophageal echocardiography found a development of right-to-left shunt flow through PFO accompanying central hypoxia during Impella P8 support. Veno-arterial ECMO was converted to veno-arterio-venous ECMO and PFO was occluded percutaneously on the next day, which stabilized hemodynamics and systemic oxygen supply. In case of Impella 5.0 support, the existence of PFO and the development of right-to-left shunt flow should be carefully surveyed and closed immediately to maintain hemodynamics and systemic oxygen supply.