Door-to-unload: left ventricular unloading before reperfusion in ST-elevation myocardial infarction.

ST-elevation myocardial infarction treatment in the modern era has focused on minimizing time of ischemia by reducing door-to-balloon time to limit infarct size and improve survival. Although there have been significant improvements in minimizing time to coronary reperfusion, the incidence of heart failure following a myocardial infarction has remained high. Preclinical studies have shown that unloading the left ventricle for 30 min prior to coronary reperfusion can reduce infarct size and promote myocardial recovery. The DTU-STEMI randomized prospective trial will test the hypothesis that left ventricular unloading for at least 30 min prior to coronary reperfusion will improve infarct size and heart failure-related events as compared with the current standard of care.

Lay abstract Improvements in the treatment of heart attacks over the years have focused on rapidly opening the blocked vessel to limit the amount of heart muscle damage. Although there have been significant improvements in minimizing the time to treatment using various options from medications to balloons and stents, there continues to be a high incidence of heart failure following a heart attack with larger heart attacks leading to more heart failure. Recent studies in animal models have shown that unloading the work of the heart with a temporary heart pump can decrease the size of the heart attack and improve heart muscle recovery. The door-to-unload research program continues to investigate the treatment strategy of unloading the heart for at least 30 min prior to opening the blocked vessel to improve patient outcomes.

Fatal or Irreversible Bleeding and Ischemic Events With Rivaroxaban in Acute Coronary Syndrome.

BACKGROUND: Net clinical outcome analyses of acute coronary syndrome (ACS) mingle fatal or irreversible events with survivable or reversible events that vary significantly in clinical impact. OBJECTIVES: A comparison of efficacy and safety limited to fatal or irreversible ischemic and adverse or seriously harmful events is one way to assess net clinical outcome and risk-benefit overall, given the fact that these events have a similar clinical impact. METHODS: In the ATLAS ACS 2-TIMI 51 (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome-Thrombolysis In Myocardial Infarction) trial of rivaroxaban in the secondary prevention of events among patients with ACS treated with aspirin plus clopidogrel or ticlopidine (clopidogrel/ticlopidine) or aspirin alone, fatal and irreversible efficacy events including nonbleeding cardiovascular death, myocardial infarction, and ischemic stroke were compared to fatal or irreversible safety events, including fatal and intracranial bleeding. RESULTS: Rivaroxaban, 2.5 mg orally twice per day, in patients treated with aspirin and clopidogrel/ticlopidine was associated with 115 (95% confidence interval [CI]: 18 to 212) fewer fatal or irreversible ischemic events (663 for placebo vs. 548 for therapy) and 10 (95% CI: -11 to 32) additional fatal or irreversible seriously harmful events (33 vs. 23 for placebo) per 10,000 patient-years of exposure. Taken together, there would be 105 (95% CI: 6 to 204) fatal or irreversible events prevented per 10,000 patient-years of exposure to rivaroxaban compared with placebo, with 11 (10 of 115) fatal or irreversible ischemic events prevented for each fatal or irreversible seriously harmful event caused. If only nonbleeding cardiovascular death is included as a fatal or irreversible event, then 95 events would be prevented per 10,000 patient-years of exposure in the group taking 2.5 mg orally twice per day. CONCLUSIONS: Both fatal or irreversible ischemia and bleeding are clinically significant events that can be compared to assess the net clinical outcomes associated with therapy. Rivaroxaban therapy at an oral dose of 2.5 mg twice daily in patients treated with aspirin and clopidogrel is associated with a net reduction in fatal or irreversible events. (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome-Thrombolysis In Myocardial Infarction [ATLAS ACS 2-TIMI 51]; NCT00809965).

EMBRACE STEMI study: a Phase 2a trial to evaluate the safety, tolerability, and efficacy of intravenous MTP-131 on reperfusion injury in patients undergoing primary percutaneous coronary intervention.

AIMS: Among patients with ST-elevation myocardial infarction (STEMI), reperfusion injury contributes to additional myocardial damage. MTP-131 is a cell-permeable peptide that preserves the integrity of cardiolipin, enhances mitochondrial energetics, and improves myocyte survival during reperfusion. METHODS AND RESULTS: EMBRACE STEMI is a multicentre, randomized, double-blind Phase 2a trial that evaluated the efficacy and safety of MTP-131 vs. placebo infused at a rate of 0.05 mg/kg/h for 1 h among first-time anterior STEMI subjects undergoing primary percutaneous coronary intervention (PCI) for a proximal or mid left anterior descending (LAD) artery occlusion. Administration of MTP-131 was not associated with a significant reduction in the primary endpoint, infarct size by creatine kinase-myocardial band (CK-MB) area under the curve (AUC) over 72 h (5785 ± 426 ng h/mL in placebo vs. 5570 ± 486 ng h/mL in MTP-131; ITALIC! P = NS). MTP-131 was not associated with an improvement in pre-specified magnetic resonance imaging, angiographic, electrocardiographic, or clinical outcomes. CONCLUSION: Among subjects with first-time anterior STEMI due to a proximal or mid LAD lesion who undergo successful PCI, administration of MTP-131 was safe and well tolerated. Treatment with MTP-131 was not associated with a decrease in myocardial infarct size as assessed by AUC0-72 of CK-MB.

Utility of a real-time appropriate use criteria decision support application for percutaneous coronary interventions in non-acute coronary syndrome.

OBJECTIVES: The aim of this study was to test the feasibility and value of a real-time online appropriate use criteria (AUC) application for percutaneous coronary intervention (PCI) in patients without acute coronary syndrome. BACKGROUND: High rates of non-appropriate elective PCI in the National Cardiovascular Data Registry (NCDR) CathPCI Registry have created interest in integrating decision support tools into routine clinical care to improve the frequency of appropriate PCIs. METHODS: Patients undergoing diagnostic coronary angiography and subsequent PCI for non-ACS indications at a single center were scored using a real-time AUC application pre-procedure. Blinded angiographic review was performed subsequently for each case. Rates of appropriate, inappropriate, uncertain and not rated PCIs were tabulated according to specific clinical scenarios using information available both before and after the angiographic audit. RESULTS: Of 308 PCIs in 272 patients, 196 (63.6%) were deemed appropriate, 79 (25.6%) uncertain, and two (0.6%) inappropriate; 31 (10.1%) scenarios could not be rated. With angiographic audit, inappropriate PCIs increased to 9.7%. There was a significant improvement in the rate of appropriate PCI using the real-time AUC application compared with retrospective data collection for NCDR reporting (64% vs. 53%, P = 0.01). CONCLUSIONS: Use of a real-time AUC application together with angiographic audit may improve the accuracy of reporting PCI appropriateness. © 2015 Wiley Periodicals, Inc.

Angiographic validation of the American College of Cardiology Foundation-the Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies study.

BACKGROUND: The goal of this study was to compare angiographic interpretation of coronary arteriograms by sites in community practice versus those made by a centralized angiographic core laboratory. METHODS AND RESULTS: The study population consisted of 2013 American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) records with 2- and 3- vessel coronary disease from 54 sites in 2004 to 2007. The primary analysis compared Registry (NCDR)-defined 2- and 3-vessel disease versus those from an angiographic core laboratory analysis. Vessel-level kappa coefficients suggested moderate agreement between NCDR and core laboratory analysis, ranging from kappa=0.39 (95% confidence intervals, 0.32-0.45) for the left anterior descending artery to kappa=0.59 (95% confidence intervals, 0.55-0.64) for the right coronary artery. Overall, 6.3% (n=127 out of 2013) of those patients identified with multivessel disease at NCDR sites had had 0- or 1-vessel disease by core laboratory reading. There was no directional bias with regard to overcall, that is, 12.3% of cases read as 3-vessel disease by the sites were read as <3-vessel disease by the core laboratory, and 13.9% of core laboratory 3-vessel cases were read as <3-vessel by the sites. For a subset of patients with left main coronary disease, registry overcall was not linked to increased rates of mortality or myocardial infarction. CONCLUSIONS: There was only modest agreement between angiographic readings in clinical practice and those from an independent core laboratory. Further study will be needed because the implications for patient management are uncertain.

Optimizing reperfusion in patients with STEMI: a critical evaluation of pharmacologic and non-pharmacologic strategies.

Among patients with ST-elevation myocardial infarction (STEMI), rapidly re-establishing normal coronary blood flow is of paramount importance. More than 25 % of hospitals in the USA do not have access to timely primary percutaneous coronary intervention, highlighting the need for clinicians to understand both pharmacologic and non-pharmacologic strategies for STEMI. This manuscript reviews the current state of the art in STEMI care, describing both pharmacologic and non-pharmacologic strategies for reperfusion.

Reduction of stent thrombosis in patients with acute coronary syndromes treated with rivaroxaban in ATLAS-ACS 2 TIMI 51.

OBJECTIVES: The aim of this study was to determine if rivaroxaban is associated with a reduction in stent thrombosis among patients with acute coronary syndromes (ACS) in the ATLAS-ACS 2 TIMI 51 (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects With Acute Coronary Syndrome-Thrombolysis in Myocardial Infarction 51) trial. BACKGROUND: Dual antiplatelet therapy (DAPT) has been the mainstay of efforts to prevent stent thrombosis. Because thrombin is a potent stimulant of platelet activation, we hypothesized that inhibition of thrombin generation via factor Xa inhibition may further reduce the risk of stent thrombosis. METHODS: The ATLAS-ACS 2 TIMI 51 study was a placebo-controlled trial that randomly assigned 15,526 patients with recent ACS to receive twice-daily doses of either 2.5 mg or 5 mg of rivaroxaban or placebo for a mean of 13 months and up to 31 months. RESULTS: Among patients who had a stent placed before or at the time of the index event, rivaroxaban significantly reduced independently adjudicated Academic Research Consortium definite and probable stent thrombosis in the pooled (1.9% vs. 1.5%; hazard ratio [HR]: 0.65; p = 0.017) and the 2.5 mg twice-daily (1.9% vs. 1.5%; HR: 0.61; p = 0.023) treatment groups when compared with placebo, with a trend toward a reduction in the 5 mg twice-daily treatment group (1.9% vs. 1.5%; HR: 0.70; p = 0.089). Among patients who received both aspirin and a thienopyridine (stratum 2), the benefit of rivaroxaban emerged during the period of active treatment with DAPT (HR: 0.68; 95% CI: 0.50 to 0.92, combined rivaroxaban group vs. placebo). Among stented patients who were treated with dual antiplatelet therapy, there was a mortality reduction among those treated with twice-daily rivaroxaban 2.5 mg (HR: 0.56; 95% CI: 0.35 to 0.89; p = 0.014). CONCLUSIONS: Among stented patients with ACS treated with DAPT, the administration of twice-daily rivaroxaban 2.5 mg was associated with a reduction in stent thrombosis and mortality. (An Efficacy and Safety Study for Rivaroxaban in Patients With Acute Coronary Syndrome; NCT00809965).

Rationale and design of the EMBRACE STEMI study: a phase 2a, randomized, double-blind, placebo-controlled trial to evaluate the safety, tolerability and efficacy of intravenous Bendavia on reperfusion injury in patients treated with standard therapy including primary percutaneous coronary intervention and stenting for ST-segment elevation myocardial infarction.

BACKGROUND: Although significant efforts have been made to improve ST-segment elevation myocardial infarction (STEMI) outcomes by reducing symptom-onset-to-reperfusion times, strategies to decrease the clinical impact of ischemic reperfusion injury have demonstrated limited success. Bendavia, an intravenously administered mitochondrial targeting peptide, has been shown to reduce myocardial infarct size and attenuate coronary no-reflow in experimental modelswhen given before reperfusion. DESIGN: The EMBRACE STEMI study is a phase 2a, randomized, double-blind, placebo-controlled trial enrolling 300 patients with a first-time anterior STEMI and an occluded proximal or mid-left anterior descending artery undergoing primary percutaneous coronary intervention (PCI) within 4 hours of symptom onset. Patients will be randomized to receive either Bendavia at 0.05 mg/kg per hour or an identically appearing placebo administered as an intravenous infusion at 60 mL/h. The primary end point is infarct size measured by the area under the creatine kinase-MB enzyme curve calculated from measurements from the central clinical chemistry laboratory obtained over the initial 72 hours after the primary PCI procedure, and the major secondary end point is infarct size calculated by the volume of infarcted myocardium (late contrast gadolinium enhancement) on the day 4±1 cardiac magnetic resonance imaging. SUMMARY: EMBRACE-STEMI is testing the hypothesis that Bendavia, in conjunction with standard-of-care therapy, is superior to placebo for the reduction of myocardial infarction size among patients with first time, acute, anterior wall STEMI who undergo successful reperfusion with primary PCI and stenting.

Mechanical circulatory support for right ventricular failure.

OBJECTIVES: The aim of this study was to explore the clinical utility of a commercially available centrifugal flow pump as a centrifugal flow-right ventricular support device (CF-RVSD) in patients with right ventricular failure (RVF). BACKGROUND: RVF is associated with high in-hospital mortality. Limited data regarding efficacy of the CF-RVSD for RVF exist. METHODS: We retrospectively reviewed data from 46 patients receiving a CF-RVSD for RVF from a registry comprising data from 8 tertiary-care hospitals in the United States. CF-RVSD use was recorded in the setting of acute myocardial infarction; myocarditis; chronic left heart failure; after valve surgery, orthotopic heart transplantation, left ventricular assist device surgery, coronary bypass grafting. Devices were implanted via the percutaneous (n = 22) or surgical (n = 24) route. RESULTS: No intraprocedural mortality was observed. Mean time from admission to CF-RVSD implantation was 5.7 ± 8.5 days, with a mean of 6,769 ± 789 rotations/min, providing 4.2 ± 1.3 l/min of flow. Mean duration of support was 5.4 ± 5.1 days. Mean arterial pressure (65 ± 12 mm Hg vs. 73 ± 14 mm Hg; p < 0.05), right atrial pressure (21 ± 8 mm Hg vs. 16 ± 7 mm Hg; p = 0.05), pulmonary artery systolic pressure (43 ± 15 mm Hg vs. 33 ± 15 mm Hg; p = 0.01), and cardiac index (1.7 ± 0.7 vs. 2.2 ± 0.6; p = 0.01) were improved within 48 h of CF-RVSD implantation. Total in-hospital mortality was 57% and was lowest in the setting of left ventricular assist device implantation, chronic left heart failure, and acute myocardial infarction. Increased age, biventricular failure, and Thrombolysis In Myocardial Infarction-defined major bleeding were associated with increased in-hospital mortality. CONCLUSIONS: Use of the CF-RVSD for RVF is clinically feasible and associated with improved hemodynamic status. Observations from the registry of patients who have received this device may support the development of prospective studies that will examine the role of percutaneous circulatory support for RVF.

Optimal selection of STEMI treatment strategies in the current era: benefit of transferring STEMI patients for PCI compared with administration of onsite fibrinolytic therapy.

PURPOSE OF REVIEW: For patients presenting with ST-elevation myocardial infarction (STEMI), primary percutaneous coronary intervention (PPCI) is superior to onsite fibrinolytic therapy (O-FT) when administered in a timely fashion. This benefit diminishes as PCI-related delay increases. This review examines recent data exploring this relationship, offering insight into possible mechanisms for the time-dependent benefit of PCI. RECENT FINDINGS: The advantage of transfer for primary PCI (X-PCI) over O-FT was analyzed in a contemporary propensity-score matched cohort by evaluating outcomes based on PCI-related delay (door-to-balloon time minus door-to-needle time). In 19 012 matched STEMI patients from the National Registry of Myocardial Infarction database, the delay to PCI wherein the mortality advantage for X-PCI was nullified compared with O-FT was approximately 120 min. Extensive delays were found to attenuate the mortality benefit of X-PCI [number needed to treat (NNT) 23 for PCI-related delay >60 min; NNT 44 for PCI-related delay 60-90 min; and NNT 250 for PCI-related delay >90 min]. SUMMARY: The benefit of PCI over O-FT appears to markedly decrease as PCI-related delay increases, particularly in the case of interhospital transfer, which can often lead to long reperfusion times. Various strategies can reduce PCI-related delays, including the establishment of STEMI systems of care and regionalization. Furthermore, alternate pharmacoinvasive strategies should be considered when significant delay to PCI is anticipated.

Admission hyperglycemia and acute myocardial infarction: outcomes and potential therapies for diabetics and nondiabetics.

Hyperglycemia, in both diabetic and nondiabetic patients, has a significant negative impact on the morbidity and mortality of patients presenting with an acute myocardial infarction (AMI). Contemporary evidence indicates that persistent hyperglycemia after initial hospital admission continues to exert negative effects on AMI patients. There have been a number of studies demonstrating the benefit of tight glucose control in patients presenting with AMI, but a lack of convincing clinical data has led to loose guidelines and poor implementation of glucose targets for this group of patients. The CREATE-ECLA study, which hypothesized that a fixed high dose of glucose, insulin, and potassium (GIK) would change myocardial substrate utilization from free fatty acids to glucose and therefore protect ischemic myocardium, failed to demonstrate improved clinical outcomes in AMI patients. Studies that specifically investigated intensive insulin therapy, including DIGAMI-2 and HI-5, also failed to improve clinical outcomes such as mortality. There are a number of reasons that these trials may have fallen short, including the inability to reach glucose targets and inadequate power. There is now a need for a large placebo-controlled randomized trial with an adequate sample size and adherence to glucose targets in order to establish the benefit of treating hyperglycemia in patients presenting with AMI.

Newer Pharmaceutical Agents for STEMI Interventions.

ST-elevation myocardial infarction (STEMI) causes 12.6% of deaths worldwide. Treatment strategies involve early revascularization by percutaneous coronary intervention and/or fibrinolytics, with adjunctive pharmacologic therapy. While antiplatelet therapy remains the cornerstone of pharmacologic management, newer antithrombotic therapies are showing benefit in the reduction of long-term thrombotic events following acute vessel occlusion. Future directions in adjunctive STEMI management include the use of hematopoietic stem cell therapy or growth factors to induce proliferation and differentiation of cardiac myocytes.

Cost-Effective Medicines for Stroke Prophylaxis in Patients with Atrial Fibrillation.

Non-valvular atrial fibrillation is the most common arrhythmia encountered in clinical practice and is associated with substantial healthcare costs. The risk of thromboembolic stroke is 3-5 times higher in patients with atrial fibrillation compared with the general population. Until the recent emergence of direct thrombin (factor IIa) and factor Xa inhibitors, antithrombotic therapy for atrial fibrillation was achieved with antiplatelet agents or vitamin K antagonists, which are considered cost-effective strategies when compared to no treatment. Now newer agents, such as the direct thrombin inhibitor dabigatran, can lower thromboembolic events and reduce the risk of fatal and intracerebral hemorrhage compared with warfarin, in addition to eliminating the need for costly therapeutic monitoring. Multiple analyses have shown that dabigatran, when compared with warfarin therapy that achieves a time in therapeutic range (TTR) consistent with previous large-scale trials, is a cost-effective approach to antithrombotic therapy in atrial fibrillation, ranging from $16,385 to $86,000 per quality-adjust life-year (QALY) gained. It has been shown to be especially cost-effective (QALY < $50,000) for high stroke-risk patients, those with a CHADS2 score of > 3 (barring excellent INR control) and for lower-risk patients with a CHADS2 of 2 but concomitant high risk of hemorrhage. In addition, factor Xa inhibitors, such as rivaroxaban (recently approved by the Federal Drug Administration [FDA]) and apixaban, may exhibit the same cost savings as dabigatran in terms of reduction of bleeding and elimination of therapeutic level monitoring costs. Going forward, the use of these agents and their role in thromboembolic stroke prophylaxis will need to be evaluated on a patient-by-patient basis, balancing consideration of the patient?s stroke and bleeding risks, as well as quality of life post-therapy.

Benefit of transferring ST-segment-elevation myocardial infarction patients for percutaneous coronary intervention compared with administration of onsite fibrinolytic declines as delays increase.

BACKGROUND: Although randomized trials suggest that transfer for primary percutaneous coronary intervention (X-PCI) in ST-segment-elevation myocardial infarction is superior to onsite fibrinolytic therapy (O-FT), the generalizability of these findings to routine clinical practice is unclear because door-to-balloon (XDB) times are rapid in randomized trials but are frequently prolonged in practice. We hypothesized that delays resulting from transfer would reduce the survival advantage of X-PCI compared with O-FT. METHODS AND RESULTS: ST-segment-elevation myocardial infarction patients enrolled in the National Registry of Myocardial Infarction (NRMI) within 12 hours of pain onset were identified. Propensity matching of patients treated with X-PCI and O-FT was performed, and the effect of PCI-related delay on in-hospital mortality was assessed. PCI-related delay was calculated by subtracting the XDB from the door-to-needle time in each matched pair. Conditional logistic regression adjusted for patient and hospital variables identified the XDB door-to-needle time at which no mortality advantage for X-PCI over O-FT was present. Eighty-one percent of X-PCI patients were matched (n=9506) to O-FT patients (n=9506). In the matched cohort, X-PCI was performed with delays >90 minutes in 68%. Multivariable analysis found no mortality advantage for X-PCI over O-FT when XDB door-to-needle time exceeded ≈120 minutes. CONCLUSION: PCI-related delays are extensive among patients transferred for X-PCI and are associated with poorer outcomes. No differential excess in mortality was seen with X-PCI compared with O-FT even with long PCI-related delays, but as XDB door-to-needle time times increase, the mortality advantage for X-PCI over O-FT declines.

Interactive effects of the ACE DD polymorphism with the NOS III homozygous G849T (Glu298-->Asp) variant in determining endothelial function in coronary artery disease.

The products of nitric oxide synthase (NOS) and angiotensin-converting enzyme (ACE) play a critical role in determining vessel wall structure and function. Polymorphisms in both genes have been independently demonstrated to influence propensity to cardiovascular events. The purpose of this study was to determine the influence of the homozygous G849T (Glu298-->Asp) polymorphism in NOS III on peripheral conduit artery endothelial function and to elucidate the modifier role, if any, of a common ACE polymorphism. Three hundred and ninety-seven consecutive subjects presenting to the cardiac catheterization laboratory of the University of Michigan over a period of 18 months were recruited. DNA was extracted and polymerase chain reaction (PCR) analysis for ACE and NOS polymorphisms performed. Patients with homozygosity for G849T at both loci (TT) who belong to DD and II ACE genotype (groups 1 and 2) and those who are negative for this polymorphism (GG) and belong to either DD or II genotype (groups 3 and 4) were identified. The four groups then underwent determination of conduit endothelial function. Heterozygosity of Glu298-Asp or the ID variant of the ACE were not studied. Median FMD value in the TT-DD group was 0.20 (-3.17, 2.01) compared with 2.23% (-0.29, 4.17) in the GG-II group. Median values in the TT-II and the GG-DD groups were 3.04 (-1.16, 6.61) and 2.46% (-1.83, 6.52) respectively. These values were not statistically significant (p > 0.05 by one-way ANOVA). Median nitroglycerin-mediated dilation in the four groups did not differ between the four groups (p = NS by ANOVA). Atherosclerosis burdens as assessed by angiography were not different across the groups. In conclusion, the homozygous NOS III variant (GG) status does not seem to interact additively with the ACE homozygous DD genotype in determining flow-mediated vasodilation in individuals with established atherosclerosis and pre-existent endothelial dysfunction.