Characterizing Active Site Conformational Heterogeneity along the Trajectory of an Enzymatic Phosphoryl Transfer Reaction

States along the phosphoryl transfer reaction catalyzed by the nucleoside monophosphate kinase UmpK were captured and changes in the conformational heterogeneity of conserved active site arginine side-chains were quantified by NMR spin-relaxation methods. In addition to apo and ligand-bound UmpK, a transition state analog (TSA) complex was utilized to evaluate the extent to which active site conformational entropy contributes to the transition state free energy. The catalytically essential arginine side-chain guanidino groups were found to be remarkably rigid in the TSA complex, indicating that the enzyme has evolved to restrict the conformational freedom along its reaction path over the energy landscape, which in turn allows the phosphoryl transfer to occur selectively by avoiding side reactions

Practical approach on frail older patients attended for acute heart failure

Acute heart failure (AHF) is a multi-organ dysfunction syndrome. In addition to known cardiac dysfunction, non-cardiac comorbidity, frailty and disability are independent risk factors of mortality, morbidity, cognitive and functional decline, and risk of institutionalization. Frailty, a treatable and potential reversible syndrome very common in older patients with AHF, increases the risk of disability and other adverse health outcomes. This position paper highlights the need to identify frailty in order to improve prognosis, the risk-benefits of invasive diagnostic and therapeutic procedures, and the definition of older-person-centered and integrated care plans

Repeat late instent-stenosis after an interval of four years in the same lesion after bare-metal and drug-eluting stent: a case report

In 2001, a 71-year old male was admitted to our hospital with unstable angina. The angiography revealed 2-vessel disease with a 90% stenosis of the proximal LAD. A bare-metal stent was implanted. Four years later the angiography showed a 80% instent-stenosis in the bare-metal stent but no progress at the other coronary arteries. A DES was implanted. Again, four years later, the patient presented with non-ST-elevation myocardial infarction. Angiography showed a 90% instent-restenosis, again without any progession of coronary artery disease in the other vessels. Again a DES implanted. Therefore the processes involved in the late instent-stenosis were not influenced by the antiproliferative agent sirolimu

Changes and prognostic value of cardiopulmonary exercise testing parameters in elderly patients undergoing cardiac rehabilitation: The EU-CaRE observational study

Objective We aimed 1) to test the applicability of the previously suggested prognostic value of CPET to elderly cardiac rehabilitation patients and 2) to explore the underlying mechanism of the greater improvement in exercise capacity (peak oxygen consumption, VO2) after CR in surgical compared to non-surgical cardiac patients. Methods Elderly patients (?65 years) commencing CR after coronary artery bypass grafting, surgical valve replacement (surgery-group), percutaneous coronary intervention, percutaneous valve replacement or without revascularisation (non-surgery group) were included in the prospective multi-center EU-CaRE study. CPETs were performed at start of CR, end of CR and 1-year-follow-up. Logistic models and receiver operating characteristics were used to determine prognostic values of CPET parameters for major adverse cardiac events (MACE). Linear models were performed for change in peak VO2 (start to follow-up) and parameters accounting for the difference between surgery and non-surgery patients were sought. Results 1421 out of 1633 EU-CaRE patients performed a valid CPET at start of CR (age 73±5.4, 81% male). No CPET parameter further improved the receiver operation characteristics significantly beyond the model with only clinical parameters. The higher improvement in peak VO2 (25% vs. 7%) in the surgical group disappeared when adjusted for changes in peak tidal volume and haemoglobin. Conclusion CPET did not improve the prediction of MACE in elderly CR patients. The higher improvement of exercise capacity in surgery patients was mainly driven by restoration of haemoglobin levels and improvement in respiratory function after sternotomy

Impact of presentation and transfer delays on complete ST-segment resolution before primary percutaneous coronary intervention: Insights from the ATLANTIC trial

Aims: The aim of this study was to identify predictors of complete ST-segment resolution (STR) pre-primary percutaneous coronary intervention (PCI) in patients enrolled in the ATLANTIC trial. Methods and results: ECGs recorded at the time of inclusion (pre-hospital [pre-H]-ECG) and in the catheterisation laboratory before angiography (pre-PCI-ECG) were analysed by an independent core laboratory. Complete STR was defined as 6570%. Complete STR occurred pre-PCI in 12.8% (204/1, 598) of patients and predicted lower 30-day composite MACCE (OR=0.10, 95% CI: 0.002-0.57, p=0.001) and total mortality (OR=0.16, 95% CI: 0.004-0.95, p=0.035). Independent predictors of complete STR included the time from index event to pre-H-ECG (OR=0.94, 95% CI: 0.89-1.00, p=0.035), use of heparins before pre- PCI-ECG (OR=1.75, 95% CI: 1.25-2.45, p=0.001) and time from pre-H-ECG to pre-PCI-ECG (OR=1.09, 95% CI: 1.03-1.16, p=0.005). In the pre-H ticagrelor group, patients with complete STR had a significantly longer delay between pre-H-ECG and pre-PCI-ECG compared to patients without complete STR (median 53 [44-73] vs. 49 [38.5-61] mins, p=0.001); however, this was not observed in the control group (in-hospital ticagrelor) (50 [40-67] vs. 49 [39-61] mins, p=0.258). Conclusions: Short patient delay, early administration of anticoagulant and ticagrelor if a long transfer delay is expected may help to achieve reperfusion prior to PCI. Pre-H treatment may be beneficial in patients with longer transfer delays, allowing the drug to become biologically active. ClinicalTrials.gov Identifier: NCT01347580

Pre-hospital administration of ticagrelor in diabetic patients with ST-elevation myocardial infarction undergoing primary angioplasty: A sub-analysis of the ATLANTIC trial

Objective: We investigated, in the contemporary era of ST-elevation myocardial infarction (STEMI) treatment, the influence of diabetes mellitus (DM) on cardiovascular outcomes, and whether pre-hospital administration of ticagrelor may affect these outcomes in a subgroup of STEMI patients with DM. Background: DM patients have high platelet reactivity and a prothrombotic condition which highlight the importance of an effective antithrombotic regimen in this high-risk population. Methods: In toal 1,630 STEMI patients enrolled in the ATLANTIC trial who underwent primary percutaneous coronary intervention (PCI) were included. Multivariate analysis was used to explore the association of DM with outcomes and potential treatment-by-diabetes interaction was tested. Results: A total of 214/1,630 (13.1%) patients had DM. DM was an independent predictor of poor myocardial reperfusion as reflected by less frequent ST-segment elevation resolution ( 6570%) after PCI (OR 0.59, 95% CI 0.43\u20130.82, P < 0.01) and was an independent predictor of the composite 30-day outcomes of death/new myocardial infarction (MI)/urgent revascularization/definite stent thrombosis (ST) (OR 2.80, 95% CI 1.62\u20134.85, P < 0.01), new MI or definite acute ST (OR 2.46, 95% CI 1.08\u20135.61, P = 0.03), and definite ST (OR 10.00, 95% CI 3.54\u201328.22, P < 0.01). No significant interaction between pre-hospital ticagrelor vs in-hospital ticagrelor administration and DM was present for the clinical, electrocardiographic and angiographic outcomes as well as for thrombolysis in myocardial infarction major bleeding. Conclusions: DM remains independently associated with poor myocardial reperfusion and worse 30-day clinical outcomes. No significant interaction was found between pre-hospital vs in-hospital ticagrelor administration and DM status. Further approaches for the treatment of DM patients are needed. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01347580

Early glycoprotein IIb–IIIa inhibitors in primary angioplasty (EGYPT) cooperation: an individual patient data meta-analysis

Background: Even though time-to-treatment has been shown to be a determinant of mortality in primary angioplasty, the potential benefits from early pharmacological reperfusion by glycoprotein (Gp) IIb-IIIa inhibitors are still unclear. The aim of this meta-analysis was to combine individual data from all randomised trials conducted on facilitated primary angioplasty by the use of early Gp IIb-IIIa inhibitors. Methods and results: The literature was scanned by formal searches of electronic databases (MEDLINE, EMBASE) from January 1990 to October 2007. All randomised trials on facilitation by the early administration of Gp IIb-IIIa inhibitors in ST-segment elevation myocardial infarction (STEMI) were examined. No language restrictions were enforced. Individual patient data were obtained from 11 out of 13 trials, including 1662 patients (840 patients (50.5%) randomly assigned to early and 822 patients (49.5%) to late Gp IIb-IIIa inhibitor administration). Preprocedural Thrombolysis in Myocardial Infarction Study (TIMI) grade 3 flow was more frequent with early Gp IIb-IIIa inhibitors. Postprocedural TIMI 3 flow and myocardial blush grade 3 were higher with early Gp IIb IIIa inhibitors but did not reach statistical significance except for abciximab, whereas the rate of complete ST-segment resolution was significantly higher with early Gp IIb-IIIa inhibitors. Mortality was not significantly different between groups, although early abciximab demonstrated improved survival compared with late administration, even after adjustment for clinical and angiographic confounding factors. Conclusions: This meta-analysis shows that pharmacological facilitation with the early administration of Gp IIb IIIa inhibitors in patients undergoing primary angioplasty for STEMI is associated with significant benefits in terms of preprocedural epicardial recanalisation and ST-segment resolution, which translated into non-significant mortality benefits except for abciximab

Efficacy and Safety of Glycoprotein IIb/IIIa Inhibitors on Top of Ticagrelor in STEMI: A Subanalysis of the ATLANTIC Trial

BACKGROUND: Glycoprotein IIb/IIIa inhibitors (GPIs) in combination with clopidogrel improve clinical outcome in ST-elevation myocardial infarction (STEMI); however, finding a balance that minimizes both thrombotic and bleeding risk remains fundamental. The efficacy and safety of GPI in addition to ticagrelor, a more potent P2Y12-inhibitor, have not been fully investigated. METHODS: 1,630 STEMI patients who underwent primary percutaneous coronary intervention (PCI) were analyzed in this subanalysis of the ATLANTIC trial. Patients were divided in three groups: no GPI, GPI administration routinely before primary PCI, and GPI administration in bailout situations. The primary efficacy outcome was a composite of death, myocardial infarction, urgent target revascularization, and definite stent thrombosis at 30 days. The safety outcome was non-coronary artery bypass graft (CABG)-related PLATO major bleeding at 30 days. RESULTS: Compared with no GPI (n\u2009=\u2009930), routine GPI (n\u2009=\u2009525) or bailout GPI (n\u2009=\u2009175) was not associated with an improved primary efficacy outcome (4.2% no GPI vs. 4.0% routine GPI vs. 6.9% bailout GPI; p\u2009=\u20090.58). After multivariate analysis, the use of GPI in bailout situations was associated with a higher incidence of non-CABG-related bleeding compared with no GPI (odds ratio [OR] 2.96, 95% confidence interval [CI] 1.32-6.64; p\u2009=\u20090.03). However, routine GPI use compared with no GPI was not associated with a significant increase in bleeding (OR 1.78, 95% CI 0.88-3.61; p\u2009=\u20090.92). CONCLUSION: Use of GPIs in addition to ticagrelor in STEMI patients was not associated with an improvement in 30-day ischemic outcome. A significant increase in 30-day non-CABG-related PLATO major bleeding was seen in patients who received GPIs in a bailout situation