Michelle L. O’Donoghue

Prasugrel compared with high loading- and maintenance-dose clopidogrel in patients with planned percutaneous coronary intervention: the Prasugrel in Comparison to Clopidogrel for Inhibition of Platelet Activation and Aggregation-Thrombolysis in Myocardial Infarction 44 trial.

Background— The increasing use of higher-than-approved doses of clopidogrel in clinical practice is based in part on the desire for greater levels of inhibition of platelet aggregation (IPA). Prasugrel is a new thienopyridine that is more potent than standard-dose clopidogrel in healthy subjects and patients with stable coronary artery disease. The relative antiplatelet effects of prasugrel versus high-dose clopidogrel in percutaneous coronary intervention patients are unknown. Methods and Results— Prasugrel in Comparison to Clopidogrel for Inhibition of Platelet Activation and Aggregation–Thrombolysis in Myocardial Infarction 44 (PRINCIPLE-TIMI 44) was a randomized, double-blind, 2-phase crossover study of prasugrel compared with high-dose clopidogrel in patients undergoing cardiac catheterization for planned percutaneous coronary intervention. The primary end point of the loading-dose phase (prasugrel 60 mg versus clopidogrel 600 mg) was IPA with 20 &mgr;mol/L ADP at 6 hours. Patients with percutaneous coronary intervention entered the maintenance-dose phase, a 28-day crossover comparison of prasugrel 10 mg/d versus clopidogrel 150 mg/d with a primary end point of IPA after 14 days of either drug. In this study, 201 subjects were randomized. IPA at 6 hours was significantly higher in subjects receiving prasugrel (mean±SD, 74.8±13.0%) compared with clopidogrel (31.8±21.1%; P<0.0001). During the maintenance-dose phase, IPA with 20 &mgr;mol/L ADP was higher in subjects receiving prasugrel (61.3±17.8%) compared with clopidogrel (46.1±21.3%; P<0.0001). Results were consistent across all key secondary end points; significant differences emerged by 30 minutes and persisted across all time points. Conclusions— Among patients undergoing cardiac catheterization with planned percutaneous coronary intervention, loading with 60 mg prasugrel resulted in greater platelet inhibition than a 600-mg clopidogrel loading dose. Maintenance therapy with prasugrel 10 mg/d resulted in a greater antiplatelet effect than 150 mg/d clopidogrel.

Lipoprotein-associated phospholipase A2 and its association with cardiovascular outcomes in patients with acute coronary syndromes in the PROVE IT-TIMI 22 (PRavastatin Or atorVastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction) trial.

Background— Lipoprotein-associated phospholipase A2 (Lp-PLA2) is associated with the risk of cardiovascular (CV) events in population-based studies. The prognostic value of Lp-PLA2 in patients with acute coronary syndromes (ACS) has not been established. Methods and Results— Plasma levels of Lp-PLA2 activity were measured at baseline (n=3648) and 30 days (n=3265) in patients randomized to atorvastatin 80 mg/d or pravastatin 40 mg/d after ACS in the PROVE IT-TIMI 22 (PRavastatin Or atorVastatin Evaluation and Infection Therapy–Thrombolysis In Myocardial Infarction) trial. The primary end point was death, myocardial infarction, unstable angina, revascularization, or stroke (mean follow-up 24 months). At baseline after ACS, the risk of recurrent CV events was similar across all quintiles of Lp-PLA2 activity (Ptrend=0.88). Overall, mean levels of Lp-PLA2 were lower at 30 days of follow-up than at baseline (35.7 versus 40.9 nmol · min−1 · mL−1, P<0.001). In particular, treatment with atorvastatin 80 mg/d was associated with a 20% reduction in Lp-PLA2 activity (P<0.001), whereas Lp-PLA2 rose 3.6% with pravastatin 40 mg/d (P<0.001). Patients with 30-day Lp-PLA2 activity in the highest quintile were at significantly increased risk of recurrent CV events compared with those in the lowest quintile (26.4% versus 17.6%, Ptrend=0.002). After adjustment for cardiac risk factors, treatments, achieved low-density lipoprotein (LDL), and C-reactive protein, Lp-PLA2 activity in the highest quintile remained independently associated with a higher risk of recurrent CV events (adjusted hazard ratio 1.33, 95% confidence interval [CI] 1.01 to 1.74). Conclusions— Lp-PLA2 is not useful for risk stratification when measured early after ACS. At 30 days, Lp-PLA2 activity is significantly lowered with high-dose statin therapy and is associated with an increased risk of CV events independent of C-reactive protein and LDL cholesterol levels.

Prognostic Utility of Heart-Type Fatty Acid Binding Protein in Patients With Acute Coronary Syndromes

Background— Heart-type fatty acid binding protein (H-FABP) is a cytosolic protein that is released rapidly from the cardiomyocyte in response to myocardial injury. Although it has been investigated as an early marker of acute myocardial infarction, its prognostic utility in acute coronary syndromes has not been established. Methods and Results— We measured H-FABP in 2287 patients with acute coronary syndromes from the OPUS-TIMI 16 trial. H-FABP was elevated (>8 ng/mL) in 332 patients (14.5%). Patients with an elevated H-FABP were more likely to suffer death (hazard ratio [HR], 4.1; 95% CI, 2.6 to 6.5), recurrent myocardial infarction (HR, 1.6; 95% CI, 1.0 to 2.5), congestive heart failure (HR, 4.5; 95% CI, 2.6 to 7.8), or the composite of these end points (HR, 2.6; 95% CI, 1.9 to 3.5) through the 10-month follow-up period. H-FABP predicted the risk of the composite end point both in patients who were troponin I negative (HR, 2.1; 95% CI, 1.3 to 3.4) and in those who were troponin I positive (HR, 3.3; 95% CI, 2.0 to 5.3). In a Cox proportional-hazards model that adjusted for baseline variables, including demographics, clinical characteristics, creatinine clearance, ST deviation, index diagnosis, and troponin I, elevated H-FABP remained a significant predictor of the composite end point (HR, 1.9; 95% CI, 1.3 to 2.7), as well as the individual end points of death (HR, 2.7; 95% CI, 1.5 to 4.9) and CHF (HR, 2.4; 95% CI, 1.2 to 5.0). In a multimarker approach, H-FABP, troponin I, and B-type natriuretic peptide provided complementary information. Conclusions— Elevation of H-FABP is associated with an increased risk of death and major cardiac events in patients presenting across the spectrum of acute coronary syndromes and is independent of other established clinical risk predictors and biomarkers.

Prognostic Utility of Lipoprotein-Associated Phospholipase A2 for Cardiovascular Outcomes in Patients With Stable Coronary Artery Disease

Objective—To determine the prognostic utility of lipoprotein-associated phospholipase A2 (Lp-PLA2) for specific adverse cardiovascular outcomes in patients with stable coronary artery disease (CAD), independent of traditional risk factors and high-sensitivity C-reactive protein (hs-CRP). Methods and Results—We measured Lp-PLA2 in 3766 patients with stable CAD from the PEACE trial. Patients were followed for a median of 4.8 years for adverse cardiovascular events including death, myocardial infarction (MI), coronary revascularization, hospitalization for unstable angina (UA), and stroke. Multivariable Cox regression was used to adjust for traditional cardiovascular risk factors and to conduct multimarker analyses that included hs-CRP. After adjustment for baseline characteristics, patients in higher quartiles of Lp-PLA2 remained at significantly greater risk for the composite of cardiovascular death, MI, coronary revascularization, UA, or stroke (P<0.001 for trend, adj HR 1.41, 95% CI 1.17 to 1.70, for patients in 4th versus 1st quartile). The association was consistent regardless of a patients sex, cholesterol levels, or use of lipid-lowering therapy. When analyzed together, both hs-CRP and Lp-PLA2 were highly significant predictors of acute coronary syndromes (cardiovascular death, MI, or UA) (P for trend <0.001 for hs-CRP and 0.005 for Lp-PLA2), whereas only Lp-PLA2 was a significant predictor of coronary revascularization (P=0.01 for trend). Conclusions—In stable CAD, an elevated level of Lp-PLA2 was a significant predictor of nonfatal adverse cardiovascular outcomes independent of traditional clinical risk factors and hs-CRP. Further investigation will be needed to establish whether therapies that lower Lp-PLA2 reduce cardiovascular risk.

Clopidogrel Response Variability and Future Therapies: Clopidogrel: Does One Size Fit All?

Case Presentation: A 75-year-old woman presents to the hospital with a non–ST-elevation myocardial infarction (MI) and is found to have a subtotal occlusion of the proximal left anterior descending coronary artery. A drug-eluting stent is successfully deployed without complication, and the patient is given a 300-mg loading dose of clopidogrel. She is started on a treatment regimen that includes aspirin 325 mg daily and clopidogrel 75 mg daily. On hospital day 4, she develops recurrent chest pain and is found to have ST-segment elevation on ECG. She is taken to coronary angiography, where she is found to have an occlusive thrombus within a well-deployed stent. After percutaneous coronary intervention (PCI), how should this patient be managed? Platelets play a central role in initiating and propagating pathological thrombosis after spontaneous or mechanical plaque rupture. Antiplatelet therapies, including aspirin and thienopyridines, are key components of pharmacotherapy in acute coronary syndromes (ACS) and PCI.1,2 As monotherapy, treatment with clopidogrel modestly reduces cardiovascular (CV) events in patients with established atherosclerotic disease compared with aspirin treatment.3 When combined with aspirin, clopidogrel provides additive reduction in the risk of ischemic events in patients with non–ST-elevation ACS and in patients undergoing PCI.4,5 In addition, clopidogrel helps to maintain infarct-related artery patency and clinical outcomes in patients with ST-elevation MI receiving fibrinolytic therapy.6,7 Clopidogrel, a prodrug, relies on cytochrome P450–dependent pathways to form its active metabolite and inhibits platelet aggregation through irreversible blockade of the platelet P2Y12 receptor (Figure 1). When a 300-mg loading dose is used, clopidogrel requires at least 4 to 6 hours to achieve its maximal effect.8 Analyses from the Clopidogrel for the Reduction of Events During Observation (CREDO) trial suggest that clopidogrel pretreatment 6 to 15 hours before PCI is necessary to significantly reduce CV events.5,9 Clinicians …

Clinical Uncertainty, Diagnostic Accuracy, and Outcomes in Emergency Department Patients Presenting With Dyspnea

BACKGROUND Dyspnea is a common complaint in the emergency department (ED) and may be a diagnostic challenge. We hypothesized that diagnostic uncertainty in this setting is associated with adverse outcomes, and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) testing would improve diagnostic accuracy and reduce diagnostic uncertainty. METHODS A total of 592 dyspneic patients were evaluated from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study. Managing physicians were asked to provide estimates from 0% to 100%of the likelihood of acutely destabilized heart failure (ADHF). A certainty estimate of either 20% or lower or 80% or higher was classified as clinical certainty, while estimates between 21% and 79% were defined as clinical uncertainty. Associations between clinical uncertainty,hospital length of stay, morbidity, and mortality were examined. The diagnostic value of clinical judgment vs NT-proBNP measurement was compared across categories of clinical certainty. RESULTS Clinical uncertainty was present in 185 patients (31%), 103 (56%) of whom had ADHF. Patients judged with clinical uncertainty had longer hospital length of stay and increased morbidity and mortality,especially those with ADHF. Receiver operating characteristic analysis of clinical judgment yielded an area under the curve (AUC) of 0.88 in the clinical certainty group and 0.76 in the uncertainty group (P<.001); NT-proBNP testing alone in these same groups had AUCs of 0.96 and 0.91, respectively. The combination of clinical judgment with NT-proBNP testing yielded improvements in AUC. CONCLUSIONS Among dyspneic patients in the ED, clinical uncertainty is associated with increased morbidity and mortality, especially in those with ADHF.The addition of NT-proBNP testing to clinical judgment may reduce diagnostic uncertainty in this setting.

Effect of losmapimod on cardiovascular outcomes in patients hospitalized with acute myocardial infarction: A randomized clinical trial

IMPORTANCE p38 Mitogen-activated protein kinase (MAPK)-stimulated inflammation is implicated in atherogenesis, plaque destabilization, and maladaptive processes in myocardial infarction (MI). Pilot data in a phase 2 trial in non-ST elevation MI indicated that the p38 MAPK inhibitor losmapimod attenuates inflammation and may improve outcomes. OBJECTIVE To evaluate the efficacy and safety of losmapimod on cardiovascular outcomes in patients hospitalized with an acute myocardial infarction. DESIGN, SETTING, AND PATIENTS LATITUDE-TIMI 60, a randomized, placebo-controlled, double-blind, parallel-group trial conducted at 322 sites in 34 countries from June 3, 2014, until December 8, 2015. Part A consisted of a leading cohort (n = 3503) to provide an initial assessment of safety and exploratory efficacy before considering progression to part B (approximately 22,000 patients). Patients were considered potentially eligible for enrollment if they had been hospitalized with an acute MI and had at least 1 additional predictor of cardiovascular risk. INTERVENTIONS Patients were randomized to either twice-daily losmapimod (7.5 mg; n = 1738) or matching placebo (n = 1765) on a background of guideline-recommended therapy. Patients were treated for 12 weeks and followed up for an additional 12 weeks. MAIN OUTCOMES AND MEASURES The primary end point was the composite of cardiovascular death, MI, or severe recurrent ischemia requiring urgent coronary revascularization with the principal analysis specified at week 12. RESULTS In part A, among the 3503 patients randomized (median age, 66 years; 1036 [29.6%] were women), 99.1% had complete ascertainment for the primary outcome. The primary end point occurred by 12 weeks in 123 patients treated with placebo (7.0%) and 139 patients treated with losmapimod (8.1%; hazard ratio, 1.16; 95% CI, 0.91-1.47; P = .24). The on-treatment rates of serious adverse events were 16.0% with losmapimod and 14.2% with placebo. CONCLUSIONS AND RELEVANCE Among patients with acute MI, use of losmapimod compared with placebo did not reduce the risk of major ischemic cardiovascular events. The results of this exploratory efficacy study did not justify proceeding to a larger efficacy trial in the existing patient population. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02145468.

Soluble ST2 Plasma Concentrations Predict 1-Year Mortality in Acutely Dyspneic Emergency Department Patients With Pulmonary Disease

We evaluated the association between ST2 concentrations and mortality at 1 year in 231 acutely dyspneic patients with pulmonary diseases seen in the emergency department. Blood concentrations of ST2 were ascertained; using 1-year survival as the reference standard, receiver operating characteristic curves with resultant area under the curve (AUC) were measured. Cox proportional hazards models identified independent predictors of 1-year death. Hazard curves compared rates of death as a function of ST2 concentration. Concentrations of ST2 were significantly higher in patients with pulmonary diseases compared with 153 subjects without cardiopulmonary disease (0.23 vs 0.11 ng/mL; P = .01). Among patients with pulmonary diseases, concentrations of ST2 were higher among decedents compared with survivors (1.14 ng/mL vs 0.19 ng/mL; P < .001). ST2 had an AUC of 0.72 as a predictor of death (P < .0001). An ST2 of 0.20 ng/mL had a hazard ratio for death of 6.1 (95% confidence interval, 1.8-21.0; P = .004). Compared with patients with lower ST2 concentrations, mortality rates for patients with an enrollment ST2 of 0.20 ng/mL or more diverged early and rose progressively in 1 year (P < .001). ST2 concentrations are frequently elevated in acute pulmonary diseases and are markedly prognostic for death by 1 year.

Safety and efficacy of protease-activated receptor-1 antagonists in patients with coronary artery disease: a meta-analysis of randomized clinical trials

Summary.  Background:  Thrombin receptor antagonists blocking protease‐activated receptor‐1 (PAR‐1) on platelets represent a new class of oral antiplatelet agents for patients with atherothrombotic disease manifestations.

Rationale and design of the LosmApimod To Inhibit p38 MAP kinase as a TherapeUtic target and moDify outcomes after an acute coronary syndromE trial

BACKGROUND p38 mitogen-activated protein kinase (MAPK) mediates cytokine production and amplification of the inflammatory cascade. Through inhibition of p38 MAPK, losmapimod appears to attenuate the inflammatory response in the vascular wall and thus may help stabilize plaques. STUDY DESIGN The LATITUDE-TIMI 60 trial is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study planned to be conducted in a 3-stage design. Overall, the trial is designed to include 25,500 patients hospitalized with non-ST-elevation or ST-elevation myocardial infarction (MI) randomized to oral losmapimod (7.5 mg twice daily) versus matching placebo. Part A consists of a leading cohort (n = 3,500) that will provide an initial assessment of safety and exploratory efficacy before progressing to part B. Part B (n = ~22,000) of the study is event driven and will provide the primary assessment of efficacy. An independent safety review will be conducted after 3,500 patients in part B1 to determine whether a more focused schedule of clinic visits and laboratory assessments can be implemented (part B2). All patients are to be treated with study drug until week 12 and followed up until week 24. The primary end point is the composite of cardiovascular death, MI, or severe recurrent ischemia requiring urgent coronary revascularization. The key secondary end point is the composite of cardiovascular death or MI. The trial is designed to provide ≥90% power for the primary end point. CONCLUSIONS The LATITUDE-TIMI 60 trial will determine the efficacy and safety of short-term p38 MAPK inhibition with losmapimod in acute MI. The trial design adopts a stepwise approach to decision making and collection of data.