Some patients with acute heart failure (AHF) who are treated initially with noninvasive ventilation (NIV) will require endotracheal intubation, which indicates NIV failure. The incidence and ...prognosis of NIV failure in patients with AHF are not well characterized.
Using the National In-Patient Sample (NIS), we conducted a retrospective cohort study of subjects hospitalized with AHF between 2008 and 2014 who were treated with NIV within 24 h of hospital admission. We determined predictors of NIV failure and determined the association between NIV failure and in-hospital mortality using Cox proportional hazard models.
Of 279,534 subjects hospitalized with AHF and treated with NIV, 4,257 (1.52%) failed NIV and required intubation. Cardiogenic shock (odds ratio 8.79, 95% CI 6.89-11.2) and in-hospital arrest (odds ratio 24.9, 95% CI 18.71-33.14) were associated with NIV failure. In-hospital mortality was 26.5% for NIV failure compared to 5.6% for those without NIV (
< .001). After adjustment for demographics, comorbidities, cardiogenic shock, and in-hospital arrest, NIV failure was associated with nearly a 2-fold risk of in-hospital mortality (odds ratio 1.95, 95% CI 1.59-2.40).
Intubation after initial NIV treatment was required in 1.5% of subjects hospitalized with AHF and treated with NIV, and was associated with high in-hospital mortality. These findings can guide future prospective interventional trials and quality improvement ventures.
Studies indicate that myocardial infarction and unstable angina result from the formation of a platelet aggregate at the site of a ruptured coronary atherosclerotic plaque.
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The formation of ...such aggregates requires the binding of fibrinogen and von Willebrand factor to the receptor, glycoprotein IIb/IIIa, on the platelet surface.
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Large trials have demonstrated a marked benefit of various inhibitors of platelet function in both preventing and reducing the mortality and morbidity associated with unstable coronary syndromes.
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Additional studies have linked ex vivo platelet reactivity to outcome in patients after myocardial infarction.
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In sum, there is strong evidence . . .
Energy metabolism is essential for myocellular viability. The high-energy phosphates adenosine triphosphate (ATP) and phosphocreatine (PCr) are reduced in human myocardial infarction (MI), reflecting ...myocyte loss and/or decreased intracellular ATP generation by creatine kinase (CK), the prime energy reserve of the heart. The pseudo-first-order CK rate constant, k, measures intracellular CK reaction kinetics and is independent of myocyte number within sampled tissue. CK flux is defined as the product of PCr and k. CK flux and k have never been measured in human MI.
Myocardial CK metabolite concentrations, k, and CK flux were measured noninvasively in 15 patients 7 weeks to 16 years after anterior MI using phosphorus magnetic resonance spectroscopy. In patients, mean myocardial ATP and PCr were 39% to 44% lower than in 15 control subjects (PCr=5.4+/-1.2 versus 9.6+/-1.1 micromol/g wet weight in MI versus control subjects, respectively, P<0.001; ATP=3.4+/-1.1 versus 5.5+/-1.3 micromol/g wet weight, P<0.001). The myocardial CK rate constant, k, was normal in MI subjects (0.31+/-0.08 s(-1)) compared with control subjects (0.33+/-0.07 s(-1)), as was PCr/ATP (1.74+/-0.27 in MI versus 1.87+/-0.45). However, CK flux was halved in MI to 1.7+/-0.5 versus 3.3+/-0.8 micromol(g . s)(-1); P<0.001.
These first observations of CK kinetics in prior human MI demonstrate that CK ATP supply is significantly reduced as a result of substrate depletion, likely attributable to myocyte loss. That k and PCr/ATP are unchanged in MI is consistent with the preservation of intracellular CK metabolism in surviving myocytes. Importantly, the results support therapies that primarily ameliorate the effects of tissue and substrate loss after MI and those that reduce energy demand rather than those that increase energy transfer or workload in surviving tissue.
The anaphase-promoting complex/cyclosome (APC/C) is a ubiquitin ligase that initiates anaphase and mitotic exit. APC/C is activated by Cdc20 and inhibited by the mitotic checkpoint complex (MCC), ...which delays mitotic exit when the spindle assembly checkpoint (SAC) is activated. We previously identified apcin as a small molecule ligand of Cdc20 that inhibits APC/CCdc20 and prolongs mitosis. Here we find that apcin paradoxically shortens mitosis when SAC activity is high. These opposing effects of apcin arise from targeting of a common binding site in Cdc20 required for both substrate ubiquitination and MCC-dependent APC/C inhibition. Furthermore, we found that apcin cooperates with p31comet to relieve MCC-dependent inhibition of APC/C. Apcin therefore causes either net APC/C inhibition, prolonging mitosis when SAC activity is low, or net APC/C activation, shortening mitosis when SAC activity is high, demonstrating that a small molecule can produce opposing biological effects depending on regulatory context.A small-molecule ligand of the APC/C activator Cdc20, which prolongs mitosis in unperturbed cells, instead shortens mitosis when the spindle checkpoint is activated, producing an opposite effect in a different regulatory context.
The extent of microvascular obstruction during acute coronary occlusion may determine the eventual magnitude of myocardial damage and thus, patient prognosis after infarction. By contrast-enhanced ...MRI, regions of profound microvascular obstruction at the infarct core are hypoenhanced and correspond to greater myocardial damage acutely. We investigated whether profound microvascular obstruction after infarction predicts 2-year cardiovascular morbidity and mortality.
Forty-four patients underwent MRI 10 +/- 6 days after infarction. Microvascular obstruction was defined as hypoenhancement seen 1 to 2 minutes after contrast injection. Infarct size was assessed as percent left ventricular mass hyperenhanced 5 to 10 minutes after contrast. Patients were followed clinically for 16 +/- 5 months. Seventeen patients returned 6 months after infarction for repeat MRI. Patients with microvascular obstruction (n = 11) had more cardiovascular events than those without (45% versus 9%; P=.016). In fact, microvascular status predicted occurrence of cardiovascular complications (chi2 = 6.46, P<.01). The risk of adverse events increased with infarct extent (30%, 43%, and 71% for small n = 10, midsized n = 14, and large n = 14 infarcts, P<.05). Even after infarct size was controlled for, the presence of microvascular obstruction remained a prognostic marker of postinfarction complications (chi2 = 5.17, P<.05). Among those returning for follow-up imaging, the presence of microvascular obstruction was associated with fibrous scar formation (chi2 = 10.0, P<.01) and left ventricular remodeling (P<.05).
After infarction, MRI-determined microvascular obstruction predicts more frequent cardiovascular complications. In addition, infarct size determined by MRI also relates directly to long-term prognosis in patients with acute myocardial infarction. Moreover, microvascular status remains a strong prognostic marker even after control for infarct size.
The benefit of intravenous thrombolytic therapy in elderly patients with myocardial infarction is uncertain. There are no randomized trials of thrombolytic efficacy or observational studies of ...clinical effectiveness that focus specifically on the elderly.
To determine whether thrombolytic therapy for elderly patients is associated with a survival advantage in a large observational database, we conducted a retrospective cohort study of 7864 Medicare fee-for-service patients aged 65 to 86 years with the primary discharge diagnosis of acute myocardial infarction who were admitted with clinical and ECG indications for thrombolytic therapy and no absolute contraindications. The study included all US acute care nongovernment hospitals without on-site angioplasty capability. Using proportional-hazards methods, we found that in a comprehensive multivariate model, there was a significant interaction (P<0.001) between age and the effect of thrombolytic therapy on 30-day mortality rates. For patients 65 to 75 years old, thrombolytic therapy was associated with a survival benefit, consistent with randomized trials. Among patients aged 76 to 86 years, thrombolytic therapy was associated with a survival disadvantage, with a 30-day mortality hazard ratio of 1.38 (95% CI 1. 12 to 1.71, P=0.003). For these patients, there was no benefit from thrombolytic therapy in any clinical subgroup.
In nationwide clinical practice, thrombolytic therapy for patients >75 years old is unlikely to confer survival benefit and may have a significant survival disadvantage. Reperfusion research that is focused on elderly patients is urgently needed.
Background Prevention of adverse remodeling after myocardial infarction (MI) is an important goal of stem cell therapy. Clinical trial results vary, however, and poor cell retention and survival ...after delivery likely limit the opportunity to exert beneficial effects. To overcome these limitations, we built an implantable intravascular bioreactor (IBR) designed to protect contained cells from washout, dilution, and immune attack while allowing sustained release of beneficial paracrine factors. Methods and Results IBRs were constructed using semipermeable membrane adhered to a clinical-grade catheter shaft. Mesenchymal stem cell (MSC) viability in and paracrine factor release from IBRs were assessed in vitro and IBR biocompatibility and immune protection confirmed in vivo. In a porcine anterior MI model, IBRs containing 25 million allogeneic MSCs (IBR-MSCs) were compared with IBRs containing media alone (IBR-Placebo; n=8 per group) with adverse remodeling assessed by magnetic resonance imaging. Four weeks after MI, IBR-MSCs had no significant change in end-diastolic volume (+0.33±4.32 mL; P=0.89), end-systolic volume (+2.14±4.13 mL; P=0.21), and left ventricular ejection fraction (-2.27±2.94; P=0.33) while IBR-Placebo had significant increases in end-diastolic volume (+10.37±3.84 mL; P=0.01) and ESV (+11.35±2.88 mL; P=0.01), and a significant decrease in left ventricular ejection fraction (-5.78±1.70; P=0.025). Eight weeks after MI, adherent pericarditis was present in 0 of 8 IBR-MSCs versus 4 of 8 IBR-Placebo (P=0.02), suggesting an anti-inflammatory effect. In a separate study, 25 million allogeneic pig MSCs directly injected in the peri-infarct zone 3 days after MI (n=6) showed no significant benefit in adverse remodeling at 4 weeks compared with IBR-MSCs. Conclusions MSCs deployed inside an implantable, removable, and potentially rechargeable bioreactor in a large animal model remain viable, are immunoprotected, and attenuate adverse remodeling 4 weeks after MI.
In this secondary analysis of the PACIFY randomized trial, we assessed whether dose and timing of fentanyl have implications for the pharmacokinetics and pharmacodynamics of ticagrelor loading during ...percutaneous coronary intervention (PCI).
Among 212 patients undergoing clinically indicated coronary angiography, a total of 70 required PCI and received 180 mg oral ticagrelor. Of these, thirty-two patients received no fentanyl and 38 received fentanyl (with variability in the timing of administration and cumulative dose among those randomized to fentanyl, given that both were provided at the interventional cardiologist's discretion). A time-weighted cumulative fentanyl exposure variable was calculated based on total dose of fentanyl and proximity in time of fentanyl administrations to the ticagrelor load. Patients were stratified based on receiving above or below the median time-weighted cumulative dose. Outcomes included ticagrelor concentrations by mass spectrometry (24-hour area under the curve) and platelet function measured using both VerifyNow platelet reactivity units (PRU) and light-transmission aggregometry (LTA).
Unadjusted ticagrelor 24-hour area under the curve was significantly lower across the categories of increasing fentanyl exposure (P=.02). In adjusted regression models, this difference only remained when comparing the no-fentanyl group with the time-weighted cumulative dose above the median group (P=.04). Similarly, with the no-fentanyl group as the reference, adjusted models testing 2-hour PRU and LTA values demonstrated significant differences (with less platelet inhibition for both tests) only among those with time-weighted cumulative fentanyl exposures above the median value (5.1 μg/min).
We have previously shown that fentanyl slows absorption of oral ticagrelor, attenuating its effect on platelet inhibition. We now demonstrate this mechanism appears to be dose- and time-dependent.
Acute coronary syndromes are a frequent cause of hospital admission
for patients with coronary artery disease. The pathophysiology of acute coronary
syndromes often involves plaque rupture or fissure ...with platelet aggregation.
Recognition of the importance of platelet aggregation resulted in several
large randomized trials testing 3 types of platelet antagonists, aspirin,
glycoprotein IIb/IIIa inhibitors, and adenosine diphosphate inhibitors. A
thorough understanding of the data, risks, and benefits of these therapies
is important to optimize treatment of the patient with an acute coronary syndrome.
Recognition that there is a great deal of interpatient variability in response
to these antiplatelet therapies highlights the need for future research in
this area.
Physiologic changes in N-terminal pro-B-type natriuretic peptide (NT-proBNP) across trimesters of pregnancy have not been well studied.
The authors aimed to measure NT-proBNP in adult women, by ...pregnancy status and trimester, in a nationally representative sample from the National Health and Nutrition Examination Survey 1999 to 2004.
We conducted a cross-sectional analysis of 2,134 women (546 pregnant) aged 20 to 40 years without a history of cardiovascular disease.
Among pregnant women in the first trimester, the prevalence of elevated NT-proBNP (>125 pg/mL) was 20.0% (SE, 6.6%) compared to 2.4% (SE, 0.8%) among women in the third trimester and 8.0% among nonpregnant women. After adjustment for demographics and cardiovascular risk factors, NT-proBNP was 44% higher (absolute difference 26.4 95% CI: 11.2-41.6 pg/mL) in the first trimester of pregnancy compared to nonpregnant women. Among pregnant women only, adjusted NT-proBNP was 46% lower (absolute difference −22.2 95% CI: −36.9 to −7.5 pg/mL) in women in the third trimester compared to women in the first trimester. NT-proBNP was inversely associated with body mass index and with systolic blood pressure.
Women in the first trimester of pregnancy had significantly higher NT-proBNP than those in the third trimester and compared to similarly aged nonpregnant women. The dynamic nature of NT-proBNP should be taken into consideration when ordering NT-proBNP lab tests in pregnant women.
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