Neutrophil Extracellular Traps and Thrombolysis Resistance: New Insights for Targeting Therapies.

BACKGROUND: Thrombosis is linked to neutrophil release of neutrophil extracellular traps (NETs). NETs are proposed as a mechanism of resistance to thrombolysis. This study intends to analyze the composition of thrombi retrieved after mechanical thrombectomy, estimate the age and organization of thrombi, and evaluate associations with the use of thrombolysis, antiplatelets, and heparin. METHODS: This retrospective observational study involved 72 samples (44 from cerebral and 28 coronary arteries), which were stained with hematoxylin and eosin, anti-NE (neutrophil elastase) antibody, and anti-histone H2B (histone H2B) antibody, representing different components in NET formation, all detectable during the later stages of NETosis, for histochemical and digital quantification of NET content. The histological and morphological evaluations of the specimens were correlated, through univariate and mediation analyses, with clinical information and therapy administered before intervention. RESULTS: The results demonstrated that the composition of cerebral and coronary thrombi differs, and there were significantly more lytic cerebral thrombi than coronary thrombi (66% versus 14%; P=0.005). There was a considerably higher expression of NETs in the cerebral thrombi as testified by the higher expression of H2B (P=0.031). Thrombolysis was remarkably associated with higher NE positivity (average marginal effect, 6.461 [95% CI, 0.7901-12.13]; P=0.02555), regardless of the origin of thrombi. There was no notable association between the administration of antiaggregant therapy/heparin and H2B/NE amount when adjusted for the thrombus location. Importantly, the age of the thrombus was the only independent predictor of NET content without any mediation of the thrombolytic treatment (P=0.014). CONCLUSIONS: The age of the thrombus is the driving force for NET content, which correlates with impaired clinical outcomes. The therapy that is currently administered does not modify NET content. This study supports the need to investigate new pharmacological approaches added to thrombolysis to prevent NET formation or enhance their disruption, such as recombinant human DNase I (deoxyribonuclease I).

Transcatheter aortic valve durability, predictors of bioprosthetic valve dysfunction, longer-term outcomes - a review.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is one of the most significant inventions in cardiology, as it provides a viable minimally invasive treatment option for patients with aortic stenosis, the most common valvular disease in the developed world and one with a poor prognosis when left untreated. Using data available to date, this review aims to discuss and identify possible predictors of TAVI valve durability - an essential requirement for the device's wide-spread use, especially in younger patients. AREAS COVERED: This article explores the main causes of bioprosthetic valve dysfunction (BVD) based on pathophysiology and available data, and reviews possible predictors of BVD including prosthesis-related, procedure-related, and patient-related factors. An emphasis is made on affectable predictors, which could potentially be targeted with prevention management and improve valve durability. A literature search of online medical databases was conducted using relevant key words and dates; significant clinical trials were identified. A brief overview of important randomized controlled trials with mid to long-term follow-up is included in this article. EXPERT OPINION: Identifying modifiable predictors of valve dysfunction presents an opportunity to enhance and predict valve durability - a necessity as patients with longer life-expectancies are being considered for the procedure.

Nonprocedural bleeding after left atrial appendage closure versus direct oral anticoagulants: A subanalysis of the randomized PRAGUE-17 trial.

INTRODUCTION: Observational studies have shown low bleeding rates in patients with atrial fibrillation (AF) treated by left atrial appendage closure (LAAC); however, data from randomized studies are lacking. This study compared bleeding events among patients with AF treated by LAAC and nonvitamin K anticoagulants (NOAC). METHODS: The Prague-17 trial was a prospective, multicenter, randomized trial that compared LAAC to NOAC in high-risk AF patients. The primary endpoint was a composite of a cardioembolic event, cardiovascular death, and major and clinically relevant nonmajor bleeding (CRNMB) defined according to the International Society on Thrombosis and Hemostasis (ISTH). RESULTS: The trial enrolled 402 patients (201 per arm), and the median follow-up was 3.5 (IQR 2.6-4.2) years. Bleeding occurred in 24 patients (29 events) and 32 patients (40 events) in the LAAC and NOAC groups, respectively. Six of the LAAC bleeding events were procedure/device-related. In the primary intention-to-treat analysis, LAAC was associated with similar rates of ISTH major or CRNMB (sHR 0.75, 95% CI 0.44-1.27, p = 0.28), but with a reduction in nonprocedural major or CRNMB (sHR 0.55, 95% CI 0.31-0.97, p = 0.039). This reduction for nonprocedural bleeding with LAAC was mainly driven by a reduced rate of CRNMB (sHR for major bleeding 0.69, 95% CI 0.34-1.39, p = .30; sHR for CRNMB 0.43, 95% CI 0.18-1.03, p = 0.059). History of bleeding was a predictor of bleeding during follow-up. Gastrointestinal bleeding was the most common bleeding site in both groups. CONCLUSION: During the 4-year follow-up, LAAC was associated with less nonprocedural bleeding. The reduction is mainly driven by a decrease in CRNMB.

Prevalence of myocardial injury in patients after acute ischaemic stroke according to standard criteria.

This study examined the prevalence of acute and chronic myocardial injury according to standard criteria in patients after acute ischaemic stroke (AIS) and its relation to stroke severity and short-term prognosis. Between August 2020 and August 2022, 217 consecutive patients with AIS were enrolled. Plasma levels of high-sensitive cardiac troponin I (hs-cTnI) were measured in blood samples obtained at the time of admission and 24 and 48 h later. The patients were divided into three groups according to the Fourth Universal Definition of Myocardial Infarction: no injury, chronic injury, and acute injury. Twelve-lead ECGs were obtained at the time of admission, 24 and 48 h later, and on the day of hospital discharge. A standard echocardiographic examination was performed within the first 7 days of hospitalization in patients with suspected abnormalities of left ventricular function and regional wall motion. Demographic characteristics, clinical data, functional outcomes, and all-cause mortality were compared between the three groups. The National Institutes of Health Stroke Scale (NIHSS) at the time of admission and the modified Rankin Scale (mRS) 90 days following hospital discharge were used to assess stroke severity and outcome. Elevated hs-cTnI levels were measured in 59 patients (27.2%): 34 patients (15.7%) had acute myocardial injury and 25 patients (11.5%) had chronic myocardial injury within the acute phase after ischaemic stroke. An unfavourable outcome, evaluated based on the mRS at 90 days, was associated with both acute and chronic myocardial injury. Myocardial injury was also strongly associated with all-cause death, with the strongest association in patients with acute myocardial injury, at 30 days and at 90 days. Kaplan-Meier survival curves showed that all-cause mortality was significantly higher in patients with acute and chronic myocardial injury than in patients without myocardial injury (P < 0.001). Stroke severity, evaluated with the NIHSS, was also associated with acute and chronic myocardial injury. A comparison of the ECG findings between patients with and without myocardial injury showed a higher occurrence in the former of T-wave inversion, ST segment depression, and QTc prolongation. In echocardiographic analysis, a new abnormality in regional wall motion of the left ventricle was identified in six patients. Chronic and acute myocardial injury with hs-cTnI elevation after AIS are associated with stroke severity, unfavourable functional outcome, and short-term mortality.

Triggers, characteristics, and hospital outcome of patients with Takotsubo syndrome: 10 years experience in a large university hospital centre.

A unique clinical feature of Takotsubo syndrome (TTS) is the stress trigger factor. Different types of triggers exist, generally divided into emotional and physical stressor. The aim was to create long-term registry of all consecutive patients with TTS across all disciplines in our large university hospital. We enrolled patients on the basis of meeting the diagnostic criteria of the international InterTAK Registry. We aimed to determine type of triggers, clinical characteristics, and outcome of TTS patients during 10 years period. In our prospective, academic, single centre registry, we enrolled 155 consecutive patients with diagnoses of TTS between October 2013 and October 2022. The patients were divided into three groups, those having unknown (n = 32; 20.6%), emotional (n = 42; 27.1%), or physical (n = 81; 52.3%) triggers. Clinical characteristics, cardiac enzyme levels, echocardiographic findings, including ejection fraction, and TTS type did not differ among the groups. Chest pain was less common in the group of patients with a physical trigger. On the other hand, arrhythmogenic disorders such as prolonged QT intervals, cardiac arrest requiring defibrillation, and atrial fibrillation were more common among the TTS patients with unknown triggers compared with the other groups. The highest in-hospital mortality was observed between patients having physical trigger (16% vs. 3.1% in TTS with emotional trigger and 4.8% in TTS with unknown trigger; P = 0.060). Conclusion: More than half of the patients with TTS diagnosed in a large university hospital had a physical trigger as a stress factor. An essential part of caring for these types of patients is the correct identification of TTS in the context of severe other conditions and the absence of typical cardiac symptoms. Patients with physical trigger have a significantly higher risk of acute heart complications. Interdisciplinary cooperation is essential in the treatment of patients with this diagnosis.

Pre-hospital delay, clinical characteristics, angiographic findings, and in-hospital mortality in young and middle-aged adults with acute coronary syndrome: a single-centre registry analysis.

There are several differences between younger and older adults with acute coronary syndrome (ACS). However, few studies have evaluated these differences. We analysed the pre-hospital time interval [symptom onset to first medical contact (FMC)], clinical characteristics, angiographic findings, and in-hospital mortality in patients aged ≤50 (group A) and 51-65 (group B) years hospitalised for ACS. We retrospectively collected data from 2010 consecutive patients hospitalised with ACS between 1 October 2018 and 31 October 2021 from a single-centre ACS registry. Groups A and B included 182 and 498 patients, respectively. ST-segment elevation myocardial infarction (STEMI) was more common in group A than group B (62.6 and 45.6%, respectively; P < 0.001). The median time from symptom onset to FMC in STEMI patients did not significantly differ between groups A and B [74 (40-198) and 96 (40-249) min, respectively; P = 0.369]. There was no difference in the rate of sub-acute STEMI (symptom onset to FMC > 24 h) between groups A and B (10.4% and 9.0%, respectively; P = 0.579). Among patients with non-ST elevation acute coronary syndrome (NSTE-ACS), 41.8 and 50.2% of those in groups A and B, respectively, presented to the hospital within 24 h of symptom onset (P = 0.219). The prevalence of previous myocardial infarction was 19.2% in group A and 19.5% in group B (P = 1.00). Hypertension, diabetes, and peripheral arterial disease were more common in group B than group A. Active smoking was more common in group A than group B (67 and 54.2%, respectively; P = 0.021). Single-vessel disease was present in 52.2 and 37.1% of participants in groups A and B, respectively (P = 0.002). Proximal left anterior descending artery was more commonly the culprit lesion in group A compared with group B, irrespective of the ACS type (STEMI, 37.7 and 24.2%, respectively; P = 0.009; NSTE-ACS, 29.4 and 21%, respectively; P = 0.140). The hospital mortality rate for STEMI patients was 1.8 and 4.4% in groups A and B, respectively (P = 0.210), while for NSTE-ACS patients it was 2.9 and 2.6% in groups A and B, respectively (P = 0.873). No significant differences in pre-hospital delay were found between young (≤50 years) and middle-aged (51-65 years) patients with ACS. Although clinical characteristics and angiographic findings differ between young and middle-aged patients with ACS, the in-hospital mortality rate did not differ between the groups and was low for both of them.

Isoprenaline modified the lipidomic profile and reduced ß-oxidation in HL-1 cardiomyocytes: In vitro model of takotsubo syndrome.

Recent studies have suggested a pathogenetic link between impaired mitochondria and Takotsubo syndrome (TTS), which is closely connected with catecholamine overstimulation, poor outcomes, and changes in lipid metabolism. We investigated the changes in lipid metabolism at the level of fatty acid ß-oxidation and changes in the intracellular lipidomic spectrum. The immortalized cell line of HL-1 cardiomyocytes was used in this study as an established in vitro model of TTS. The cells were exposed to the non-selective ß-agonist isoprenaline (ISO) for acute (2 h) and prolonged (24 h) periods. We investigated the impact on mitochondrial adenosine 5'-triphosphate (ATP) production and ß-oxidation using real-time cell metabolic analysis, total lipid content, and changes in the lipidomic spectrum using high-performance liquid chromatography (HPLC) and mass spectrometry. Furthermore, modifications of selected lipid transporters were determined using real-time - polymerase chain reaction (RT-PCR) and/or Western blot techniques. By choosing this wide range of targets, we provide a detailed overview of molecular changes in lipid metabolism during catecholamine overstimulation. The present study demonstrates that acute exposure to ISO decreased ATP production by up to 42.2%, and prolonged exposure to ISO decreased ß-oxidation by 86.4%. Prolonged exposure to ISO also increased lipid accumulation by 4%. Lipid spectrum analysis of prolonged exposure to ISO showed a reduced concentration of cardioprotective and an increased concentration of lipotoxic lipid molecules during long-term exposure. Decreased lipid utilization can lead to higher intracellular lipid accumulation and the formation of lipotoxic molecules. Changes in the lipid spectrum can induce pathophysiological signaling pathways leading to cardiomyocyte remodeling or apoptosis. Thus, changes in lipid metabolism induced by excessive doses of catecholamines may cause TTS and contribute to a progression of heart failure, which is at increased risk after a TTS episode.

Hypoxia-Induced Sarcoplasmic Reticulum Ca2+ Leak Is Reversed by Ryanodine Receptor Stabilizer JTV-519 in HL-1 Cardiomyocytes.

BACKGROUND: To assess whether hypoxia, as can be found in obstructive sleep apnea syndrome, is causally associated with the development of heart failure through a direct effect on calcium leakage from the sarcoplasmic reticulum. METHODS: The impact of hypoxia on sarcoplasmic reticulum calcium leakage and expres- sion of RyR2 (ryanodine receptor2) and SERC2a (sarcoplasmic reticulum Ca2+ATPase 2a) was investigated together with the outcomes of JTV-519 and S107 treatment. HL-1 car- diomyocytes were cultured for 7 days on gas-permeable cultureware under control (12% O2) or hypoxic (1% O2) conditions with or without JTV-519 or S107. SRCL was assessed using a Fluo-5N probe. Gene and protein expression was analyzed using qPCR and western blotting. RESULTS: Hypoxic exposure increased sarcoplasmic reticulum calcium leakage by 39% and reduced RyR2 gene expression by 52%. No effect on RyR2 protein expression was observed. Treatment with 1µM JTV-519 reduced sarcoplasmic reticulum calcium leakage by 52% and 35% under control and hypoxic conditions, respectively. Administration of 1 µM JTV-519 increased RyR2 gene expression by 89% in control conditions. No effect on SRCL, RyR2, or SERC2a gene, or protein expression was observed with S107 treatment. CONCLUSION: Hypoxia increased sarcoplasmic reticulum calcium leakage which was ame- liorated by JTV-519 treatment independently of gene or protein expression. JTV-519 rep- resents a possible treatment for obstructive sleep apnea-associated HF.

Partial upper sternotomy for aortic valve replacement provides similar mid-term outcomes as the full sternotomy.

Background: Minimally invasive aortic valve replacement via upper partial sternotomy (MiniAVR) provides very good short-term results and delivers certain advantages in the postoperative course. There is limited data regarding the mid-term mortality and morbidity following this minimally invasive surgery. Methods: We provide a retrospective analysis of the patients, undergoing MiniAVR versus full sternotomy (FS) for aortic valve replacement with biological prosthesis. As the primary combined end-point the combination of death, stroke, and rehospitalization within 3 years postoperatively was defined. Data have been collected from National Cardiac Surgery Registry and insurance companies. Results: Two hundred consecutive patients with aortic valve replacement (100 ministernotomy in MiniAVR group and 100 full sternotomy in FS group) with biological prosthesis were included in this study. Ministernotomy had longer cross-clamp and bypass times (median difference 6.5 min, P=0.005, and 8.5 min, P=0.002 respectively). Patients operated via upper partial sternotomy had a lower postoperative bleeding [300 mL (IQR, 290) vs. 365 mL (IQR, 207), P=0.031]. There was no difference in the 3-year mortality (14% vs. 11%, P=0.485). The mean number of readmission 3 years after surgery per capita was almost the same in both groups (1.65 vs. 1.60, P=0.836). Median time to the first readmission was longer in the MiniAVR group (difference 8.9 months). The incidence of combined end-point during 3 years postoperatively in both groups was not statistically different (P=0.148), as well as readmissions from cardio-vascular reasons (subhazard ratio 0.90, P=0.693). Conclusions: Upper partial sternotomy can be performed safely for aortic valve replacement, without increased risk of death, stroke or re-admission in 3 years postoperatively.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) in Patients after Acute Stroke: Relation to Stroke Severity, Myocardial Injury, and Impact on Prognosis.

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is known to be associated with poor prognosis after cardiovascular events. We aimed to assess the dynamic changes in TRAIL levels and the relation of TRAIL level to stroke severity, its impact on the short-term outcomes, and its association with markers of cardiac injury in patients after acute stroke. METHODS: Between August 2020 and August 2021, 120 consecutive patients, 104 after acute ischemic stroke (AIS), 76 receiving reperfusion therapy, and 16 patients after intracerebral hemorrhage (ICH) were enrolled in our study. Blood samples were obtained from patients at the time of admission, 24 h later, and 48 h later to determine the plasma level of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitive Troponin I (hs-TnI). Twelve-lead ECGs were obtained at the time of admission, 24 h later, 48 h later, and at the release of the patients. Evaluations were performed using the National Institutes of Health Stroke Scale (NIHSS) at the time of admission and using the modified Rankin Scale (mRS) 90 days following the patient's discharge from the hospital. RESULTS: We observed a connection between lower TRAIL levels and stroke severity evaluated using the NIHSS (p = 0.044) on the first day. Lower TRAIL showed an association with severe disability and death as evaluated using the mRS at 90 days, both after 24 (p = 0.0022) and 48 h (p = 0.044) of hospitalization. Moreover, we observed an association between lower TRAIL and NT-proBNP elevation at the time of admission (p = 0.039), after 24 (p = 0.043), and after 48 h (p = 0.023) of hospitalization. In the ECG analysis, lower TRAIL levels were associated with the occurrence of premature ventricular extrasystoles (p = 0.043), and there was an association with prolonged QTc interval (p = 0.052). CONCLUSIONS: The results show that lower TRAIL is associated with stroke severity, unfavorable functional outcome, and short-term mortality in patients after acute ischemic stroke. Moreover, we described the association with markers of cardiac injury and ECG changes.

Long-term follow-up in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention.

Long-term follow-up after primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI) beyond 5 years is poorly described. There are no risk-stratification systems available for routine use. This retrospective, academic, two-centre analysis included consecutive patients who presented with acute STEMI between March 2008 and December 2019. In total, 5263 patients underwent pPCI; all patients were included in the analysis only once. Baseline characteristics were gathered from prospective local registries and based on initial hospitalization. The study enrolled 5263 patients who had been treated with pPCI; it found that cardiovascular mortality was the most frequent cause of death (65.0%) on long-term follow-up to 12 years. Myocardial infarction associated mortality was 27.2%. Cardiovascular mortality was dominant, including in the landmark analysis beyond 1 year. Multivariate analysis identified significant predictors for long-term cardiovascular mortality: age, history of diabetes mellitus, history of renal insufficiency, history of heart failure, Killip class, and successful pPCI at presentation. A predictive model was built to evaluate the risk of cardiovascular death with a high discrimination value (C-statistic = 0.84). Cardiovascular diseases remain the leading cause of long-term mortality after pPCI in the Central European population. Our novel predictive model provides risk stratification; it could identify patients who would experience the greatest benefit from aggressive secondary prevention measures.

Patient characteristics, treatment strategy, outcomes, and hospital costs of acute coronary syndrome: 3 years of data from a large high-volume centre in Central Europe.

Managing patients with acute coronary syndrome (ACS) in an ageing population with comorbidities is clinically and economically challenging. Well-conducted unselected registries are essential for providing information on real-day clinical practice. The aim was to create a long term, very detail-controlled registry of unselected patients admitted with ACS to a high-volume centre in Central Europe. Consecutive patients admitted with confirmed ACS were entered into the prospective registry from 1 October 2018 to 30 September 2021. Data on 214 parameters, including clinical characteristics, angiographic findings, laboratory and therapeutic findings, financial costs, and in-hospital mortality, were obtained for all patients. Analyses were performed on the complete dataset of 1804 patients. Of these patients, 694 (38.5%) were admitted for ST-segment elevation myocardial infarction (STEMI) and 1110 (61.5%) were admitted for non-ST-elevation (NSTE)-ACS [779 with NSTE myocardial infarction (NSTE-MI) and 331 with unstable angina (UA)]. Almost all patients (99%) underwent coronary angiography. Primary percutaneous coronary intervention (PCI) was performed in 93.4% of STEMI patients and 74.5% of NSTE-ACS patients. Patients with NSTE-MI had the longest total hospital stay (8.1 ± 9.1 days) and highest financial costs (8579.5 ± 7173.2 euros). In-hospital mortality was 1.2% in UA, 6.2% in NSTE-MI, and 10.9% in STEMI patients. Age older than 75 years, pre-hospital cardiac arrest and/or mechanical ventilation, subacute STEMI, and ejection fraction below 40% were the most powerful predictors of in-hospital mortality as assessed by multivariate analyses. The in-hospital mortality of unselected NSTE-MI and STEMI patients in daily practice is not low despite very good implementation of guideline-recommended therapy with a high rate of revascularization. The highest financial costs are associated with NSTE-MI.

Predictors allowing early discharge after interventional treatment of acute coronary syndrome patients.

Many scoring systems for predicting the outcomes of patients with acute coronary syndrome (ACS) have been proposed. In some populations, a significant reduction in length of hospital stay may be achieved without compromising patient prognoses. However, the use of such scoring systems in clinical practice is limited. The aim of this study was to propose a universal list of predictors that can identify low-risk ACS patients who may be eligible for an earlier hospital discharge without increased short-term risk for major adverse cardiac events. A cohort of 1420 patients diagnosed with ACS were enrolled into a single-centre registry between October 2018 and December 2020. Clinical, laboratory, echocardiographic, and angiographic measurements were taken for each patient and entered into the study database. Using retrospective univariant analyses of patients treated with percutaneous coronary intervention (PCI) (n = 932), we compared each predictor to 30-day mortality rate using the Czech national registry of dead people. Eleven predictors correlate significantly with 30-day survival: age <80 years, ejection fraction >50%, no cardiopulmonary resuscitation, no mechanical ventilation needed, Killip class I at admission, haemoglobin levels >110 g/L while hospitalized, successful PCI procedure(s), no residual stenosis over 90%, Thrombolysis in Myocardial Infarction 3 flow after PCI, no left main stem disease, and no triple-vessel coronary artery disease. In all, presence of all predictors applies to 328 patients (35.2% of the cohort), who maintained a 100% survival rate at 30 days. A combination of clinical, echocardiographic, and angiographic findings provides valuable information for predicting the outcomes of patients with all types of ACS. We created a simple, useful tool for selecting low-risk patients eligible for early discharge.

Might simplification of transcatheter aortic valve implantation reduce the burden on hospital resources?

Transcatheter aortic valve implantation (TAVI) varies considerably in terms of the procedural approach taken and the hospital length of stay (LoS); both directly affect the cost of care. Our coronary and standard cardiology unit aimed to simplify TAVI (and thus shorten the LoS) while maintaining safety. A shorter LoS would also reduce the burden on hospital resources and free up beds for other patients. Data on 214 consecutive patients undergoing TAVI at a single centre between April 2018 and March 2021 were retrospectively collected. A simplified protocol was implemented in January 2020; patients were stratified by whether they underwent TAVI before or after simplification. All procedural phases were simplified. For cost comparison purposes, the LoS was defined as the number of hospitalization days from admission to discharge. The total hospitalization cost was the sum of the direct and indirect (including reallocated overhead) costs. The LoS fell significantly (by 36%) after TAVI simplification. The times in the coronary care unit (CCU) and standard cardiac unit (SCU) also fell significantly (by 33% and 37% respectively). Patients in the simplified TAVI group were discharged, on average, 6 days after admission. The CCU costs decreased by 31% and the SCU costs by 39%. Transcatheter aortic valve implantation simplification did not compromise safety. Indeed, patients who underwent the simplified procedure seemed to develop fewer complications, especially bleeding. Transcatheter aortic valve implantation simplification significantly reduced the LoS and other costs without compromising patient safety.

Comparison of a Bioresorbable, Magnesium-Based Sirolimus-Eluting Stent with a Permanent, Everolimus-Eluting Metallic Stent for Treating Patients with Acute Coronary Syndrome: the PRAGUE-22 Study.

BACKGROUND: Magnesium-based bioresorbable Magmaris stents are rapidly resorbed. Few randomized studies have evaluated the efficacy of such stents in patients with acute coronary syndrome. AIM: To investigate late lumen loss as assessed via quantitative coronary angiography (QCA) and optical coherence tomography (OCT) in patients with acute coronary syndrome treated with Magmaris stents or permanent, everolimus-eluting metallic Xience stents. METHODS AND RESULTS: This PRAGUE-22 study was a two-centre, investigator-initiated, randomized study. Fifty patients were randomized based on the inclusion criteria for acute coronary syndrome and the anatomical suitability to receive Magmaris or Xience stents. The patient characteristics did not differ between the Magmaris group (n = 25) and Xience group (n = 25). The mean ages were 57.0 ± 10.5 vs. 55.5 ± 9.2 years (p = 0.541) and the total implanted stent length was 24.6 ± 10.7 mm vs. 27.6 ± 11.1 mm (p = 0.368), respectively. Four clinical events occurred in the Magmaris group and one in the Xience group during 12 months of follow-up. The extent of late lumen loss (assessed via QCA) at 12 months was greater in the Magmaris group than in the Xience group (0.54 ± 0.70 vs. 0.11 ± 0.37 mm; p = 0.029). The late lumen loss diameter (measured via OCT) in the Magmaris group was also significantly larger than that in the Xience group (0.59 ± 0.37 vs. 0.22 ± 0.20 mm; p = 0.01). CONCLUSION: Implantation of a magnesium-based bioresorbable stent in patients with acute coronary syndrome is associated with a greater extent of late lumen loss at the 12-month follow-up compared with implantation of a permanent, everolimus-eluting metallic stent. TRIAL REGISTRATION: ISRCTN89434356.

4-Year Outcomes After Left Atrial Appendage Closure Versus Nonwarfarin Oral Anticoagulation for Atrial Fibrillation.

BACKGROUND: The PRAGUE-17 (Left Atrial Appendage Closure vs Novel Anticoagulation Agents in Atrial Fibrillation) trial demonstrated that left atrial appendage closure (LAAC) was noninferior to nonwarfarin direct oral anticoagulants (DOACs) for preventing major neurological, cardiovascular, or bleeding events in patients with atrial fibrillation (AF) who were at high risk. OBJECTIVES: This study sought to assess the prespecified long-term (4-year) outcomes in PRAGUE-17. METHODS: PRAGUE-17 was a randomized noninferiority trial comparing percutaneous LAAC (Watchman or Amulet) with DOACs (95% apixaban) in patients with nonvalvular AF and with a history of cardioembolism, clinically-relevant bleeding, or both CHA2DS2-VASc ≥3 and HASBLED ≥2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically relevant bleeding, or procedure-/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat. RESULTS: This study randomized 402 patients with AF (201 per group, age 73.3 ± 7.0 years, 65.7% male, CHA2DS2-VASc 4.7 ±1.5, HASBLED 3.1 ± 0.9). After 3.5 years median follow-up (1,354 patient-years), LAAC was noninferior to DOACs for the primary endpoint by modified intention-to-treat (subdistribution HR [sHR]: 0.81; 95% CI: 0.56-1.18; P = 0.27; P for noninferiority = 0.006). For the components of the composite endpoint, the corresponding sHRs were 0.68 (95% CI: 0.39-1.20; P = 0.19) for cardiovascular death, 1.14 (95% CI: 0.56-2.30; P = 0.72) for all-stroke/transient ischemic attack, 0.75 (95% CI: 0.44-1.27; P = 0.28) for clinically relevant bleeding, and 0.55 (95% CI: 0.31-0.97; P = 0.039) for nonprocedural clinically relevant bleeding. The primary endpoint outcomes were similar in the per-protocol (sHR: 0.80; 95% CI: 0.54-1.18; P = 0.25) and on-treatment (sHR: 0.82; 95% CI: 0.56-1.20; P = 0.30) analyses. CONCLUSIONS: In long-term follow-up of PRAGUE-17, LAAC remains noninferior to DOACs for preventing major cardiovascular, neurological, or bleeding events. Furthermore, nonprocedural bleeding was significantly reduced with LAAC. (PRAGUE-17 [Left Atrial Appendage Closure vs Novel Anticoagulation Agents in Atrial Fibrillation]; NCT02426944).

Incorporation of Fibrin, Platelets, and Red Blood Cells into a Coronary Thrombus in Time and Space.

We describe the internal structure, spatial organization and dynamic formation of coronary artery thrombi from ST-segment elevation myocardial infarction patients. Scanning electron microscopy (SEM) revealed significant differences among four groups of patients (<2 hours; 2-6 hours; 6-12 hours, and >12 hours) related to the time of ischemia. Coronary artery thrombi from patients presenting less than 2 hours after the infarction were almost entirely composed of platelets, with small amounts of fibrin and red blood cells. In contrast, thrombi from late presenters (>12 hours) consisted of mainly platelets at the distal end, where clotting was initiated, with almost no platelets at the proximal end, while the red blood cell content went from low at the initiating end to more than 90% at the proximal end. Furthermore, fibrin was present mainly on the outside of the thrombi and older thrombi contained thicker fibers. The red blood cells in late thrombi were compressed to a close-packed, tessellated array of polyhedral structures, called polyhedrocytes. Moreover, there was redistribution from the originally homogeneous composition to fibrin and platelets to the outside, with polyhedrocytes on the interior. The presence of polyhedrocytes and the redistribution of components are signs of in vivo clot contraction (or retraction). These results suggest why later thrombi are resistant to fibrinolytic agents and other treatment modalities, since the close-packed polyhedrocytes form a nearly impermeable seal. Furthermore, it is of particular clinical significance that these findings suggest specific disparate therapies that will be most effective at different stages of thrombus development.