Internalization of Tissue Factor-Rich Microvesicles by Platelets Occurs Independently of GPIIb-IIIa, and Involves CD36 Receptor, Serotonin Transporter and Cytoskeletal Assembly.

Platelets are important in hemostasis, but also detect particles and pathogens in the circulation. Phagocytic and endocytic activities of platelets are widely recognized; however, receptors and mechanisms involved remain poorly understood. We previously demonstrated that platelets internalize and store phospholipid microvesicles enriched in human tissue factor (TF+MVs) and that platelet-associated TF enhances thrombus formation at sites of vascular damage. Here, we investigate the mechanisms implied in the interactions of TF+MVs with platelets and the effects of specific inhibitory strategies. Aggregometry and electron microscopy were used to assess platelet activation and TF+MVs uptake. Cytoskeletal assembly and activation of phosphoinositide 3-kinase (PI3K) and RhoA were analyzed by western blot and ELISA. Exposure of platelets to TF+MVs caused reversible platelet aggregation, actin polymerization and association of contractile proteins to the cytoskeleton being maximal at 1 min. The same kinetics were observed for activation of PI3K and translocation of RhoA to the cytoskeleton. Inhibitory strategies to block glycoprotein IIb-IIIa (GPIIb-IIIa), scavenger receptor CD36, serotonin transporter (SERT) and PI3K, fully prevented platelet aggregation by TF+MVs. Ultrastructural techniques revealed that uptake of TF+MVs was efficiently prevented by anti-CD36 and SERT inhibitor, but only moderately interfered by GPIIb-IIIa blockade. We conclude that internalization of TF+MVs by platelets occurs independently of receptors related to their main hemostatic function (GPIIb-IIIa), involves the scavenger receptor CD36, SERT and engages PI3-Kinase activation and cytoskeletal assembly. CD36 and SERT appear as potential therapeutic targets to interfere with the association of TF+MVs with platelets and possibly downregulate their prothrombotic phenotype.

Transcription factor KLF6 upregulates expression of metalloprotease MMP14 and subsequent release of soluble endoglin during vascular injury.

After endothelial injury, the transcription factor Krüppel-like factor 6 (KLF6) translocates into the cell nucleus to regulate a variety of target genes involved in angiogenesis, vascular repair and remodeling, including components of the membrane transforming growth factor beta (TGF-ß) receptor complex such as endoglin and activin receptor-like kinase 1. The membrane metalloproteinase 14 (MMP14 or MT1-MMP) targets endoglin to release soluble endoglin and is involved in vascular inflammation and endothelial tubulogenesis. However, little is known about the regulation of MMP14 expression during vascular wounding. In vitro denudation of monolayers of human endothelial cell monolayers leads to an increase in the KLF6 gene transcriptional rate, followed by an upregulation of MMP14 and release of soluble endoglin. Concomitant with this process, MMP14 co-localizes with endoglin in the sprouting endothelial cells surrounding the wound border. MMP14 expression at mRNA and protein levels is increased by ectopic KLF6 and downregulated by KLF6 suppression in cultured endothelial cells. Moreover, after wire-induced endothelial denudation, Klf6 (+/-) mice show lower levels of MMP14 in their vasculature compared with their wild-type siblings. Ectopic cellular expression of KLF6 results in an increased transcription rate of MMP14, and chromatin immunoprecipitation assays show that KLF6 interacts with MMP14 promoter in ECs, this interaction being enhanced during wound healing. Furthermore, KLF6 markedly increases the transcriptional activity of different reporter constructs of MMP14 gene promoter. These results suggest that KLF6 regulates MMP14 transcription and is a critical player of the gene expression network triggered during endothelial repair.

Mobilization of endothelial progenitor cells in acute cardiovascular events in the PROCELL study: time-course after acute myocardial infarction and stroke.

The mobilization pattern and functionality of endothelial progenitor cells after an acute ischemic event remain largely unknown. The aim of our study was to characterize and compare the short- and long-term mobilization of endothelial progenitor cells and circulating endothelial cells after acute myocardial infarction or atherothrombotic stroke, and to determine the relationship between these cell counts and plasma concentrations of vascular cell adhesion molecule (VCAM-1) and Von Willebrand factor (VWF) as surrogate markers of endothelial damage and inflammation. In addition, we assessed whether endothelial progenitor cells behave like functional endothelial cells. We included 150 patients with acute myocardial infarction or atherothrombotic stroke and 145 controls. Endothelial progenitor cells [CD45-, CD34+, KDR+, CD133+], circulating endothelial cells [CD45-, CD146+, CD31+], VWF, and VCAM-1 levels were measured in controls (baseline only) and in patients within 24h (baseline) and at 7, 30, and 180 days after the event. Myocardial infarction patients had higher counts of endothelial progenitor cells and circulating endothelial cells than the controls (201.0/mL vs. 57.0/mL; p<0.01 and 181.0/mL vs. 62.0/mL; p<0.01). Endothelial progenitor cells peaked at 30 days post-infarction (201.0/mL vs. 369.5/mL; p<0.01), as did VCAM-1 (573.7 ng/mL vs. 701.8 ng/mL; p<0.01). At 180 days post-infarction, circulating endothelial cells and VWF decreased, compared to baseline. In stroke patients, the number of endothelial progenitor cells - but not circulating endothelial cells - was higher than in controls (90.0/mL vs. 37.0/mL; p=0.01; 105.0/mL vs. 71.0/mL; p=0.11). At 30 days after stroke, however, VCAM-1 peaked (628.1/mL vs. 869.1/mL; p<0.01) but there was no significant change in endothelial progenitor cells (90/mL vs. 78/mL; p<0.34). At 180 days after stroke, circulating endothelial cells and VWF decreased, compared to baseline. Cultured endothelial progenitor cells from controls and myocardial infarction patients had endothelial phenotype characteristics and exhibited functional differences in adhesion and Ca(2+) influx, but not in proliferation and vasculogenesis. In myocardial infarction patients, VCAM-1 levels and mobilization of endothelial progenitor cells peaked at 30 days after the ischemic event. Although a similar VCAM-1 kinetic was observed in stroke patients, endothelial progenitor cells did not increase. Endothelial progenitor cells had mature endothelial capabilities in vitro.

Kv1.3 channels modulate human vascular smooth muscle cells proliferation independently of mTOR signaling pathway.

Phenotypic modulation (PM) of vascular smooth muscle cells (VSMCs) is central to the process of intimal hyperplasia which constitutes a common pathological lesion in occlusive vascular diseases. Changes in the functional expression of Kv1.5 and Kv1.3 currents upon PM in mice VSMCs have been found to contribute to cell migration and proliferation. Using human VSMCs from vessels in which unwanted remodeling is a relevant clinical complication, we explored the contribution of the Kv1.5 to Kv1.3 switch to PM. Changes in the expression and the functional contribution of Kv1.3 and Kv1.5 channels were studied in contractile and proliferating VSMCs obtained from human donors. Both a Kv1.5 to Kv1.3 switch upon PM and an anti-proliferative effect of Kv1.3 blockers on PDGF-induced proliferation were observed in all vascular beds studied. When investigating the signaling pathways modulated by the blockade of Kv1.3 channels, we found that anti-proliferative effects of Kv1.3 blockers on human coronary artery VSMCs were occluded by selective inhibition of MEK/ERK and PLCγ signaling pathways, but were unaffected upon blockade of PI3K/mTOR pathway. The temporal course of the anti-proliferative effects of Kv1.3 blockers indicates that they have a role in the late signaling events essential for the mitogenic response to growth factors. These findings establish the involvement of Kv1.3 channels in the PM of human VSMCs. Moreover, as current therapies to prevent restenosis rely on mTOR blockers, our results provide the basis for the development of novel, more specific therapies.

Vascular injury triggers Krüppel-like factor 6 mobilization and cooperation with specificity protein 1 to promote endothelial activation through upregulation of the activin receptor-like kinase 1 gene.

RATIONALE: Activin receptor-like kinase-1 (ALK1) is an endothelial transforming growth factor ß receptor involved in angiogenesis. ALK1 expression is high in the embryo vasculature, becoming less detectable in the quiescent endothelium of adult stages. However, ALK1 expression becomes rapidly increased after angiogenic stimuli such as vascular injury. OBJECTIVE: To characterize the molecular mechanisms underlying the regulation of ALK1 on vascular injury. METHODS AND RESULTS: Alk1 becomes strongly upregulated in endothelial (EC) and vascular smooth muscle cells of mouse femoral arteries after wire-induced endothelial denudation. In vitro denudation of monolayers of human umbilical vein ECs also leads to an increase in ALK1. Interestingly, a key factor in tissue remodeling, Krüppel-like factor 6 (KLF6) translocates to the cell nucleus during wound healing, concomitantly with an increase in the ALK1 gene transcriptional rate. KLF6 knock down in human umbilical vein ECs promotes ALK1 mRNA downregulation. Moreover, Klf6(+/-) mice have lower levels of Alk1 in their vasculature compared with their wild-type siblings. Chromatin immunoprecipitation assays show that KLF6 interacts with ALK1 promoter in ECs, and this interaction is enhanced during wound healing. We demonstrate that KLF6 is transactivating ALK1 gene, and this transactivation occurs by a synergistic cooperative mechanism with specificity protein 1. Finally, Alk1 levels in vascular smooth muscle cells are not directly upregulated in response to damage, but in response to soluble factors, such as interleukin 6, released from ECs after injury. CONCLUSIONS: ALK1 is upregulated in ECs during vascular injury by a synergistic cooperative mechanism between KLF6 and specificity protein 1, and in vascular smooth muscle cells by an EC-vascular smooth muscle cell paracrine communication during vascular remodeling.

Allogeneic adipose stem cell therapy in acute myocardial infarction.

BACKGROUND: Stem cell therapy offers a promising approach to reduce the long-term mortality rate associated with heart failure after acute myocardial infarction (AMI). To date, in vivo translational studies have not yet fully studied the immune response to allogeneic adipose tissue-derived mesenchymal stem cells (ATMSCs). We analysed the immune response and the histological and functional effects of allogeneic ATMSCs in a porcine model of reperfused AMI and determine the effect of administration timing. DESIGN: Pigs that survived AMI (24/26) received intracoronary administration of culture medium after reperfusion (n = 6), ATMSCs after reperfusion (n = 6), culture medium 7 days after AMI (n = 6) or ATMSCs 7 days after AMI (n = 6). At 3-week follow-up, cardiac function, alloantibodies and histological analysis were evaluated. RESULTS: Administration of ATMSCs after reperfusion and 7 days after AMI resulted in similar rates of cell engraftment; some of those cells expressed endothelial, smooth muscle and cardiomyogenic cell lineage markers. Delivery of ATMSCs after reperfusion compared with that performed at 7 days was more effective in increasing: vascular density (249 ± 64 vs. 161 ± 37 vessels/mm2; P < 0.01), T lymphocytes (1 ± 0.4 vs. 0.4 ± 0.3% of area CD3(+) ; P < 0.05) and expression of vascular endothelial growth factor (VEGF; 32 ± 7% vs. 20 ± 4% of area VEGF(+) ; P < 0.01). Allogeneic ATMSC-based therapy did not change ejection fraction but generated alloantibodies. CONCLUSIONS: The present study is the first to demonstrate that allogeneic ATMSCs elicit an immune response and, when administered immediately after reperfusion, are more effective in increasing VEGF expression and neovascularization.

Cardio4Health Study, a Cardiac Telerehabilitation Pilot Program Aimed at Patients After an Ischemic Event: Cross-sectional Study.

BACKGROUND: Center-based cardiac rehabilitation programs (CRPs) reduce morbidity and mortality after an ischemic cardiac event; however, they are widely underused. Home-based CRP has emerged as an alternative to improve patient adherence; however, its safety and efficacy remain unclear, especially for older patients and female patients. OBJECTIVE: This study aimed to develop a holistic home-based CRP for patients with ischemic heart disease and evaluate its safety and impact on functional capacity, adherence to a healthy lifestyle, and quality of life. METHODS: The 8-week home-based CRP included patients of both sexes, with no age limit, who had overcome an acute myocardial infarction in the previous 3 months, had a left ventricular ejection fraction of ≥40%, and had access to a tablet or mobile device. The CRP was developed using a dedicated platform designed explicitly for this purpose and included 3 weekly exercise sessions combining tailored aerobic and strength training and 2 weekly educational session focused on lifestyle habits, therapeutic adherence, and patient empowerment. RESULTS: We initially included 62 patients, of whom 1 was excluded for presenting with ventricular arrhythmias during the initial stress test, 5 were excluded because of incompatibility, and 6 dropped out because of a technological barrier. Ultimately, 50 patients completed the program: 85% (42/50) were male, with a mean age of 58.9 (SD 10.3) years, a mean left ventricular ejection fraction of 52.1% (SD 6.72%), and 25 (50%) New York Heart Association functional class I and 25 (50%) New York Heart Association II-III. The CRP significantly improved functional capacity (+1.6 metabolic equivalent tasks), muscle strength (arm curl test +15.5% and sit-to-stand test +19.7%), weekly training volume (+803 metabolic equivalent tasks), adherence to the Mediterranean diet, emotional state (anxiety), and quality of life. No major complications occurred, and adherence was excellent (>80%) in both the exercise and educational sessions. In the subgroup analysis, CRP showed equivalent beneficial effects irrespective of sex and age. In addition, patient preferences for CRP approaches were equally distributed, with one-third (14/50, 29%) of the patients preferring a face-to-face CRP, one-third (17/50, 34%) preferring a telematic CRP, and one-third (18/50, 37%) preferring a hybrid approach. Regarding CRP duration, 63% (31/50) of the patients considered it adequate, whereas the remaining 37% (19/50) preferred a longer program. CONCLUSIONS: A holistic telematic CRP dedicated to patients after an ischemic cardiac event, irrespective of sex and age, is safe and, in our population, has achieved positive results in improving maximal aerobic capacity, weekly training volume, muscle strength, quality of life, compliance with diet, and anxiety symptoms. The preference for a center- or home-based CRP approach is diverse among the study population, emphasizing the need for a tailored CRP to improve adherence and completion rates.

Antithrombotic and prohemorrhagic actions of different concentrations of apixaban in patients exposed to single and dual antiplatelet regimens.

We evaluated modifications in the hemostatic balance of different concentrations of apixaban (APIX) in 25 healthy donors and 53 patients treated with aspirin (ASA, n = 21), ASA and clopidogrel (ASA + CLOPI, n = 11), or ASA and ticagrelor (ASA + TICA, n = 21). Blood samples from participants were spiked ex vivo with apixaban 0 (APIX0), 40 (APIX40), and 160 ng/mL (APIX160). We assessed the effects of APIX on (1) clot formation, by ROTEM thromboelastometry; (2) thrombin generation primed by platelets; and (3) platelet and fibrin interactions with a thrombogenic surface, in a microfluidic model with circulating blood. APIX caused dose-related prolongations of clotting time with minimal impact on other ROTEM parameters. Thrombin generation was significantly inhibited by APIX160, with ASA + TICA actions showing the strongest inhibition (p < 0.01 vs APIX0). Microfluidic studies showed that APIX160 was more potent at suppressing platelet and fibrin interactions (p < 0.001 vs. APIX0). APIX40 demonstrated a consistent antithrombotic action but with a favorable protective effect on the structural quality of fibrin. APIX potentiated the antithrombotic effects of current antiplatelet regimens. APIX at 40 ng/mL, enhanced the antithrombotic action of single or dual antiplatelet regimens but was more conservative for hemostasis than the 160 ng/mL concentration.

Clinical profile and prognosis of young patients with ST-elevation myocardial infarction managed by the emergency-intervention Codi IAM network.

INTRODUCTION AND OBJECTIVES: Data on the clinical profile and outcomes of younger patients with ST-elevation myocardial infarction (STEMI) is scarce. This study compared clinical characteristics and outcomes between patients aged<45 years and those aged ≥ 45 years with STEMI managed by the acute myocardial infarction code (AMI Code) network. Sex-based differences in the younger cohort were also analyzed. METHODS: This multicenter study collected individual data from the Catalonian AMI Code network. Between 2015 and 2020, we enrolled patients with an admission diagnosis of STEMI. Primary endpoints were all-cause mortality within 30 days, 1 year, and 2 years. RESULTS: Overall, 18 933 patients (23% female) were enrolled. Of them, 1403 participants (7.4%) were aged<45 years. Younger patients with STEMI were more frequently smokers (P<.001) and presented with cardiac arrest and TIMI flow 0 before pPCI (P<.05), but the time from first medical contact to wire crossing was shorter than in the older group (P<.05). All-cause mortality rates were lower in patients aged<45 years (P<.001). Among younger patients, cardiogenic shock was most prevalent in women than in their male counterparts (P=.002), with the time from symptom onset to reperfusion being longer (P<.05). Compared with men aged<45 years, younger women were less likely to undergo pPCI (P=.004). CONCLUSIONS: Despite showing high-risk features on admission, young patients exhibit better outcomes than older patients. Differences in ischemia times and treatment were observed between men and women.

Long-term outcomes of extended DAPT in a real-life cohort of consecutive STEMI patients.

INTRODUCTION AND OBJECTIVES: Dual antiplatelet therapy (DAPT) duration after ST-segment elevation myocardial infarction (STEMI) remains a matter of debate. METHODS: We analyzed the effect of DAPT on 5-year all-cause mortality, cardiovascular mortality, and cardiovascular readmission or mortality in a cohort of 1-year survivor STEMI patients. RESULTS: A total of 3107 patients with the diagnosis of STEMI were included: 93% of them were discharged on DAPT, a therapy that persisted in 275 high-risk patients at 5 years. Cardiovascular mortality in patients on single antiplatelet therapy vs DAPT at 5 years was 1.4% vs 3.6% (P <.01), respectively, whereas noncardiovascular mortality was 3.3% vs 5.8% (P=.049) at 5 years. Cardiovascular readmission or mortality in patients with single antiplatelet therapy vs DAPT was 11.4% vs 46.5% (P <.001). Extended DAPT was independently associated with worse 5-year all-cause mortality (HR, 2.16; 95%CI, 1.40-3.33), cardiovascular mortality (HR, 2.83; 95%CI, 1.37-5.84), and cardiovascular readmission or mortality (HR, 5.20; 95%CI, 3.96-6.82). These findings were confirmed in propensity score matching and inverse probability weighting analyses. CONCLUSIONS: Our results suggest the hypothesis that, in 1-year STEMI survivors, extending DAPT up to 5 years in high-risk patients does not improve their long-term prognosis.

An open secret in porcine acute myocardial infarction models: The relevance of anaesthetic regime and breed in ischaemic outcomes.

Large animal models of acute myocardial infarction (AMI) play a crucial role in translating novel therapeutic approaches to patients as denoted by their use in the right-before-human testing platform. At present, the porcine model of AMI is used most frequently as it mimics the human condition and its anatomopathological features accurately. We want to describe to, and share with, the translational research community our experience of how different anaesthetic protocols (sevoflurane, midazolam, ketamine+xylazine+midazolam, and propofol) and pig breeds [Large White and Landrace x Large White (LLW)] can dramatically modify the outcomes of a well-established porcine model of closed-chest AMI. Our group has extensive experience with the porcine model of reperfused AMI and, over time, we reduced the time of ischaemia used to induce the disease from 90 to 50 min to increase the salvageable myocardium for cardioprotection studies. For logistical reasons, we changed both the anaesthetic protocol and the pig breed used, but these resulted in a dramatic reduction in the size of the myocardial infarct, to almost zero in some cases (sevoflurane, 50-min ischaemia, LLW, 2.4 ± 3.9% infarct size), and the cardiac function was preserved. Therefore, we had to re-validate the model by returning to 90 min of ischaemia. Here, we report the differences in infarct size and cardiac function, measured by different modalities, for each combination of anaesthetic protocol and pig breed we have used. Furthermore, we discuss these combinations and the limited literature pertaining to how these two factors influence cardiac function and infarct size in the porcine model of AMI.

Blood glucose monitoring during hospitalisation: Advanced practice nurse and semi-automated insulin prescription tools.

INTRODUCTION: Hyperglycemia is very common in hospitalized patients and is associated with worse clinical outcomes. AIMS: We implemented a clinical and educational program to improve the overall glycemic control during hospital admission, and, in patients with HbA1c > 8%, to improve their metabolic control after hospital admission. METHODS: Non-critical patients admitted to cardiovascular areas between October-2017 and February-2019. The program was led by an advanced nurse practitioner (ANP) and included a semiautomated insulin prescription tool. Program in 3 phases: 1) observation of routine practice, 2) implementation, and 3) follow-up after discharge. RESULTS: During the implementation phase the availability of HbA1c increased from 42 to 81%, and the ANP directly intervened in 73/685 patients (11%), facilitating treatment progression at discharge in 48% (de novo insulin in 36%). One-year after discharge, HbA1c in patients who were admitted during the observation phase with HbA1c > 8% (n = 101) was higher than similar patients admitted during implementation phase (8,6 ±â€¯1,5 vs. 7,3 ±â€¯1,2%, respectively, p < 0,001). We evaluated 47710 point of care capillary blood glucose (POC-glucose) in two 9 months periods (one before, one during the program) in cardiology and cardiovascular surgery wards. POC-glucose ≥250 mg/dl (pre vs. during: cardiology 10,7 vs. 8,4%, and surgery 7,4 vs. 4,5%, both p < 0,05) and <70 mg/dl (2,3 vs. 0,8% y 1,5 vs 1%, p < 0,05), respectively, improved during the program. CONCLUSIONS: The program allowed improving inpatient glycemic control, detect patients with poor glycemic control, and optimize metabolic control 1-year after discharge.

Impact of Chronic Kidney Disease in Chronic Total Occlusion Management and Clinical Outcomes.

BACKGROUND: Data on the impact of chronic kidney disease (CKD) on clinical outcomes in chronic total occlusion (CTO) patients is scarce, and the optimal treatment strategy for this population is not well established. This study aims to compare differences in CTO management and long-term clinical outcomes, including all-cause and cardiac mortalities, according to baseline glomerular filtration rate (GFR). METHODS: All patients with at least one CTO diagnosed in our center between 2010 and 2014 were included. Demographic and clinical data were registered. All-cause and cardiac mortalities were assessed during a median follow-up of 4.03 years (IQR 2.6-4.8). Clinical outcomes were compared between patients with CKD (GFR < 60 mL/min/1.73 m2) and without CKD (GFR ≥ 60 mL/min/1.73 m2). RESULTS: A total of 1248 patients (67.3 ± 10.9 years; 32% CKD) were identified. CKD patients were older and had a higher prevalence of hypertension, type 2 diabetes, peripheral arterial disease, and severe left ventricular dysfunction compared to patients with normal renal function (p < 0.05). Subjects with renal dysfunction were more often treated with MT alone, compared to patients without CKD (63% vs 45%; p < 0.001), who were more likely to undergo PCI or surgery. During follow-up, 386 patients [31%] died. CKD patients had a higher rate of all-cause and cardiac mortalities compared to patients without CKD (p < 0.001). The independent predictors for all-cause mortality were age, GFR < 60 mL/min/1.73 m2, Syntax Score I, and successful revascularization of the CTO (CABG or PCI-CTO). Among patients with CKD, advanced age, eGFR <30 mL/min/1.73 m2, and CTO successful revascularization were predictors of all-cause mortality. CONCLUSIONS: Patients with CKD were more often treated with MT alone. At long-term follow-up, revascularization of the CTO is associated with lower all-cause and cardiac mortalities in this population.

Characterization of ion channels involved in the proliferative response of femoral artery smooth muscle cells.

OBJECTIVE: Vascular smooth muscle cells (VSMCs) contribute significantly to occlusive vascular diseases by virtue of their ability to switch to a noncontractile, migratory, and proliferating phenotype. Although the participation of ion channels in this phenotypic modulation (PM) has been described previously, changes in their expression are poorly defined because of their large molecular diversity. We obtained a global portrait of ion channel expression in contractile versus proliferating mouse femoral artery VSMCs, and explored the functional contribution to the PM of the most relevant changes that we observed. METHODS AND RESULTS: High-throughput real-time polymerase chain reaction of 87 ion channel genes was performed in 2 experimental paradigms: an in vivo model of endoluminal lesion and an in vitro model of cultured VSMCs obtained from explants. mRNA expression changes showed a good correlation between the 2 proliferative models, with only 2 genes, Kv1.3 and Kvbeta2, increasing their expression on proliferation. The functional characterization demonstrates that Kv1.3 currents increased in proliferating VSMC and that their selective blockade inhibits migration and proliferation. CONCLUSIONS: These findings establish the involvement of Kv1.3 channels in the PM of VSMCs, providing a new therapeutical target for the treatment of intimal hyperplasia.

Myocardial Injury in COVID-19 Patients: Association with Inflammation, Coagulopathy and In-Hospital Prognosis.

The exact mechanisms leading to myocardial injury in the coronavirus disease 2019 (COVID-19) are still unknown. In this retrospective observational study, we include all consecutive COVID-19 patients admitted to our center. They were divided into two groups according to the presence of myocardial injury. Clinical variables, Charlson Comorbidity Index (CCI), C-reactive protein (CRP), CAC (COVID-19-associated coagulopathy), defined according to the ISTH score, treatment and in-hospital events were collected. Between March and April 2020, 331 COVID-19 patients were enrolled, 72 of them (21.8%) with myocardial injury. Patients with myocardial injury showed a higher CCI score (median (interquartile range), 5 (4-7) vs. 2 (1-4), p = 0.001), higher CRP values (18.3 (9.6-25.9) mg/dL vs. 12.0 (5.4-19.4) mg/dL, p ˂ 0.001) and CAC score (1 (0-2) vs. 0 (0-1), p = 0.001), and had lower use of any anticoagulant (57 patients (82.6%) vs. 229 patients (90.9%), p = 0.078), than those without. In the adjusted logistic regression, CRP, myocardial injury, CCI and CAC score were positive independent predictors of mortality, whereas anticoagulants resulted as a protective factor. Myocardial injury in COVID-19 patients is associated with inflammation and coagulopathy, resulting in a worse in-hospital prognosis. Treatment with anticoagulant agents may help to improve in-hospital outcomes.

Pulmonary ridge coverage and device-related thrombosis after left atrial appendage occlusion.

AIMS: The aim of this study was to evaluate the impact of pulmonary ridge (PR) coverage on both clinical and imaging follow-up outcomes in patients undergoing left atrial appendage occlusion (LAAO). METHODS AND RESULTS: The study included consecutive patients with non-valvular atrial fibrillation who underwent LAAO with disc and lobe devices. Patients were classified into two groups according to the PR coverage. A total of 147 patients were included. Among these, the PR was covered in 109 (74%) and uncovered in 38 (26%). Successful implantation was achieved in 98.6%. No differences in procedural outcomes were observed between the groups. The rate of procedural major adverse events was 3% (only major bleedings and/or vascular access complications). No device embolisation, cardiac tamponade or in-hospital mortality was observed. After a mean follow-up of 1.77±2.2 years, the annualised ischaemic stroke and major bleeding rate was 1.3%/year and 6.5%/year, respectively, without differences between groups. At follow-up, patients with a covered PR presented a lower incidence of device-related thrombosis (DRT) (1%) than those with an uncovered PR (27%); p<0.001. In multivariable analysis, the presence of PR coverage emerged as an independent predictor of DRT. CONCLUSIONS: Pulmonary ridge coverage was associated with a lower incidence of DRT after LAAO. Procedural and follow-up clinical outcomes did not differ between covered PR and uncovered PR patients.

Randomized Trial of Empagliflozin in Nondiabetic Patients With Heart Failure and Reduced Ejection Fraction.

BACKGROUND: Large clinical trials established the benefits of sodium-glucose cotransporter 2 inhibitors in patients with diabetes and with heart failure with reduced ejection fraction (HFrEF). The early and significant improvement in clinical outcomes is likely explained by effects beyond a reduction in hyperglycemia. OBJECTIVES: The purpose of this study was to assess the effect of empagliflozin on left ventricular (LV) function and volumes, functional capacity, and quality of life (QoL) in nondiabetic HFrEF patients. METHODS: In this double-blind, placebo-controlled trial, nondiabetic HFrEF patients (n = 84) were randomized to empagliflozin 10 mg daily or placebo for 6 months. The primary endpoint was change in LV end-diastolic and -systolic volume assessed by cardiac magnetic resonance. Secondary endpoints included changes in LV mass, LV ejection fraction, peak oxygen consumption in the cardiopulmonary exercise test, 6-min walk test, and quality of life. RESULTS: Empagliflozin was associated with a significant reduction of LV end-diastolic volume (-25.1 ± 26.0 ml vs. -1.5 ± 25.4 ml for empagliflozin vs. placebo, respectively; p < 0.001) and LV end-systolic volume (-26.6 ± 20.5 ml vs. -0.5 ± 21.9 ml for empagliflozin vs. placebo; p < 0.001). Empagliflozin was associated with reductions in LV mass (-17.8 ± 31.9 g vs. 4.1 ± 13.4 g, for empagliflozin vs. placebo, respectively; p < 0.001) and LV sphericity, and improvements in LV ejection fraction (6.0 ± 4.2 vs. -0.1 ± 3.9; p < 0.001). Patients who received empagliflozin had significant improvements in peak O2 consumption (1.1 ± 2.6 ml/min/kg vs. -0.5 ± 1.9 ml/min/kg for empagliflozin vs. placebo, respectively; p = 0.017), oxygen uptake efficiency slope (111 ± 267 vs. -145 ± 318; p < 0.001), as well as in 6-min walk test (81 ± 64 m vs. -35 ± 68 m; p < 0.001) and quality of life (Kansas City Cardiomyopathy Questionnaire-12: 21 ± 18 vs. 2 ± 15; p < 0.001). CONCLUSIONS: Empagliflozin administration to nondiabetic HFrEF patients significantly improves LV volumes, LV mass, LV systolic function, functional capacity, and quality of life when compared with placebo. Our observations strongly support a role for sodium-glucose cotransporter 2 inhibitors in the treatment of HFrEF patients independently of their glycemic status. (Are the "Cardiac Benefits" of Empagliflozin Independent of Its Hypoglycemic Activity? [ATRU-4] [EMPA-TROPISM]; NCT03485222).

Effects of adipose tissue-derived stem cell therapy after myocardial infarction: impact of the route of administration.

BACKGROUND: Cell-based therapies offer a promising approach to reducing the short-term mortality rate associated with heart failure after a myocardial infarction. The aim of the study was to analyze histological and functional effects of adipose tissue-derived stem cells (ADSCs) after myocardial infarction and compare 2 types of administration pathways. METHODS AND RESULTS: ADSCs from 28 pigs were labeled by transfection. Animals that survived myocardial infarction (n = 19) received: intracoronary culture media (n = 4); intracoronary ADSCs (n = 5); transendocardial culture media (n = 4); or transendocardial ADSCs (n = 6). At 3 weeks' follow-up, intracoronary and transendocardial administration of ADSCs resulted in similar rates of engrafted cells (0.85 [0.19-1.97] versus 2 [1-2] labeled cells/cm(2), respectively; P = NS) and some of those cells expressed smooth muscle cell markers. The intracoronary administration of ADSCs was more effective in increasing the number of small vessels than transendocardial administration (223 +/- 40 versus 168 +/- 35 vessels/mm(2); P < .05). Ejection fraction was not modified by stem cell therapy. CONCLUSIONS: This is the first study to compare intracoronary and transendocardial administration of autologous ADSCs in a porcine model of myocardial infarction. Both pathways of ADSCs delivery are feasible, producing a similar number of engrafted and differentiated cells, although intracoronary administration was more effective in increasing neovascularization.

Sex-based differences in chronic total occlusion management and long-term clinical outcomes.

BACKGROUND: Sex differences in coronary artery disease presentation and outcomes have been described. The aim of this study was to compare sex disparities in chronic total occlusion (CTO) management and long-term outcomes. METHODS: All consecutive patients with at least one CTO diagnosed in our center between 2010 and 2014 were included. Demographic and clinical data were registered. All-cause and cardiac mortality were assessed during a median follow-up of 4.03 years (IQR 2.6-4.8). RESULTS: A total of 1248 patients (67.3 ± 10.9 years; 16% female) were identified. Women were older, had a higher prevalence of type 2 DM and a lower ventricle ejection fraction compared to men (p < .05). Although women had major proportion of positive result for severe ischemia-viability test (86% vs. 74%; p = .01), they were more often treated with MT alone compared to male (57% vs 51%; p = .02). During follow-up, 386 patients (31%) died. Women presented a higher rate of all-cause and cardiac mortality, and hospitalizations for heart failure independently of treatment strategy, compared to men (p < .001). In multivariable analysis female sex was associated with higher cardiac mortality [HR 1.67, 95% CI 1.10-2.57; p < .001]. Among women, the independent predictors for all-cause and cardiac mortalities were age, MT of the CTO and ACEF (age, creatinin and ejection fraction) score. CONCLUSIONS: A significant sex gap regarding CTO treatment was observed. Female sex was an independent predictor for cardiac mortality at long-term follow-up. More data are needed to support these findings.

Kv1.3 blockade inhibits proliferation of vascular smooth muscle cells in vitro and intimal hyperplasia in vivo.

The modulation of voltage-gated K+ (Kv) channels, involved in cell proliferation, arises as a potential therapeutic approach for the prevention of intimal hyperplasia present in in-stent restenosis (ISR) and allograft vasculopathy (AV). We studied the effect of PAP-1, a selective blocker of Kv1.3 channels, on development of intimal hyperplasia in vitro and in vivo in 2 porcine models of vascular injury. In vitro phenotypic modulation of VSMCs was associated to an increased functional expression of Kv1.3 channels, and only selective Kv1.3 channel blockers were able to inhibit porcine VSMC proliferation. The therapeutic potential of PAP-1 was then evaluated in vivo in swine models of ISR and AV. At 15-days follow-up, morphometric analysis demonstrated a substantial reduction of luminal stenosis in the allografts treated with PAP-1 (autograft 2.72 ± 1.79 vs allograft 10.32 ± 1.92 vs allograft + polymer 13.54 ± 8.59 vs allograft + polymer + PAP-1 3.06 ± 1.08 % of luminal stenosis; P = 0.006) in the swine model of femoral artery transplant. In the pig model of coronary ISR, using a prototype of PAP-1-eluting stent, no differences were observed regarding % of stenosis compared to control stents (31 ± 13 % vs 37 ± 18%, respectively; P = 0.372) at 28-days follow-up. PAP-1 treatment was safe and did not impair vascular healing in terms of delayed endothelialization, inflammation or thrombosis. However, an incomplete release of PAP-1 from stents was documented. We conclude that the use of selective Kv1.3 blockers represents a promising therapeutic approach for the prevention of intimal hyperplasia in AV, although further studies to improve their delivery method are needed to elucidate its potential in ISR.