Apolipoprotein A1 Infusions and Cardiovascular Outcomes after Acute Myocardial Infarction

BACKGROUND

Cardiovascular events frequently recur after acute myocardial infarction, and low cholesterol efflux - a process mediated by apolipoprotein A1, which is the main protein in high-density lipoprotein - has been associated with an increased risk of cardiovascular events. CSL112 is human apolipoprotein A1 derived from plasma that increases cholesterol efflux capacity. Whether infusions of CSL112 can reduce the risk of recurrent cardiovascular events after acute myocardial infarction is unclear.

METHODS

We conducted an international, double-blind, placebo-controlled trial involving patients with acute myocardial infarction, multivessel coronary artery disease, and additional cardiovascular risk factors. Patients were randomly assigned to receive either four weekly infusions of 6 g of CSL112 or matching placebo, with the first infusion administered within 5 days after the first medical contact for the acute myocardial infarction. The primary end point was a composite of myocardial infarction, stroke, or death from cardiovascular causes from randomization through 90 days of follow-up.

RESULTS

A total of 18,219 patients were included in the trial (9112 in the CSL112 group and 9107 in the placebo group). There was no significant difference between the groups in the risk of a primary end-point event at 90 days of follow-up (439 patients [4.8%] in the CSL112 group vs. 472 patients [5.2%] in the placebo group; hazard ratio, 0.93; 95% confidence interval [CI], 0.81 to 1.05; P = 0.24), at 180 days of follow-up (622 patients [6.9%] vs. 683 patients [7.6%]; hazard ratio, 0.91; 95% CI, 0.81 to 1.01), or at 365 days of follow-up (885 patients [9.8%] vs. 944 patients [10.5%]; hazard ratio, 0.93; 95% CI, 0.85 to 1.02). The percentage of patients with adverse events was similar in the two groups; a higher number of hypersensitivity events was reported in the CSL112 group.

CONCLUSIONS

Among patients with acute myocardial infarction, multivessel coronary artery disease, and additional cardiovascular risk factors, four weekly infusions of CSL112 did not result in a lower risk of myocardial infarction, stroke, or death from cardiovascular causes than placebo through 90 days. (Funded by CSL Behring; AEGIS-II ClinicalTrials.gov number, NCT03473223.).

Effect of CSL112 on Recurrent Myocardial Infarction and Cardiovascular Death: Insights from the AEGIS-II Trial

BACKGROUND

The AEGIS-II trial hypothesized that CSL112, an intravenous formulation of human apoA-I, would lower the risk of plaque disruption, decreasing the risk of recurrent events such as myocardial infarction (MI) among high-risk patients with MI.

OBJECTIVES

This exploratory analysis evaluates the effect of CSL112 therapy on the incidence of CV death and recurrent MI.

METHODS

The AEGIS-II trial was an international, multicenter, randomized, double-blind, placebo-controlled trial that randomized 18,219 high-risk acute MI patients to 4 weekly infusions of apoA-I (6g CSL112) or placebo.

RESULTS

The incidence of the composite of cardiovascular death and type 1 MI was 11-16% lower in the CSL112 group over the study period (HR of 0.84 [95% CI 0.7-1.0; p=0.056] day 90, HR 0.86, [95% CI 0.74-0.99; p=0.048] day 180, and HR 0.89, [95% CI 0.79-1.01 p=0.07; p=0.07] day 365). Similarly, the incidence of CV death or any MI was numerically lower in CSL112 treated patients throughout the follow-up period (HR 0.92 [95% CI 0.8-1.05], 0.89 [95% CI 0.79-0.996], 0.91 [0.82-1.01]. The effect of CSL112 treatment on MI was predominantly observed for type 1 MI and type 4b (MI due to stent thrombosis).

CONCLUSION

While CSL112 did not significantly reduce the occurrence of the primary study endpoints, patients treated with CSL112 infusions had numerically lower rates of CV death and MI, type-1 MI, and stent thrombosis-related MI compared to placebo. These findings could suggest a role of apoA-I in reducing subsequent plaque disruption events via enhanced cholesterol efflux. Further prospective data would be needed to confirm these observations.

ApoA-I Infusion Therapies Following Acute Coronary Syndrome: Past, Present, and Future

PURPOSE OF REVIEW

The elevated adverse cardiovascular event rate among patients with low high-density lipoprotein cholesterol (HDL-C) formed the basis for the hypothesis that elevating HDL-C would reduce those events. Attempts to raise endogenous HDL-C levels, however, have consistently failed to show improvements in cardiovascular outcomes. However, steady-state HDL-C concentration does not reflect the function of this complex family of particles. Indeed, HDL functions correlate only weakly with serum HDL-C concentration. Thus, the field has pivoted from simply raising the quantity of HDL-C to a focus on improving the putative anti-atherosclerotic functions of HDL particles. Such functions include the ability of HDL to promote the efflux of cholesterol from cholesterol-laden macrophages. Apolipoprotein A-I (apoA-I), the signature apoprotein of HDL, may facilitate the removal of cholesterol from atherosclerotic plaque, reduce the lesional lipid content and might thus stabilize vulnerable plaques, thereby reducing the risk of cardiac events. Infusion of preparations of apoA-I may improve cholesterol efflux capacity (CEC). This review summarizes the development of apoA-I therapies, compares their structural and functional properties and discusses the findings of previous studies including their limitations, and how CSL112, currently being tested in a phase III trial, may overcome these challenges.

RECENT FINDINGS

Three major ApoA-I-based approaches (MDCO-216, CER-001, and CSL111/CSL112) have aimed to enhance reverse cholesterol transport. These three therapies differ considerably in both lipid and protein composition. MDCO-216 contains recombinant ApoA-I Milano, CER-001 contains recombinant wild-type human ApoA-I, and CSL111/CSL112 contains native ApoA-I isolated from human plasma. Two of the three agents studied to date (apoA-1 Milano and CER-001) have undergone evaluation by intravascular ultrasound imaging, a technique that gauges lesion volume well but does not assess other important variables that may relate to clinical outcomes. ApoA-1 Milano and CER-001 reduce lecithin-cholesterol acyltransferase (LCAT) activity, potentially impairing the function of HDL in reverse cholesterol transport. Furthermore, apoA-I Milano can compete with and alter the function of the recipient's endogenous apoA-I. In contrast to these agents, CSL112, a particle formulated using human plasma apoA-I and phosphatidylcholine, increases LCAT activity and does not lead to the malfunction of endogenous apoA-I. CSL112 robustly increases cholesterol efflux, promotes reverse cholesterol transport, and now is being tested in a phase III clinical trial. Phase II-b studies of MDCO-216 and CER-001 failed to produce a significant reduction in coronary plaque volume as assessed by IVUS. However, the investigation to determine whether the direct infusion of a reconstituted apoA-I reduces post-myocardial infarction coronary events is being tested using CSL112, which is dosed at a higher level than MDCO-216 and CER-001 and has more favorable pharmacodynamics.

Rationale and design of ApoA-I Event Reducing in Ischemic Syndromes II (AEGIS-II): A phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group study to investigate the efficacy and safety of CSL112 in subjects after acute myocardial infarction

Acute myocardial infarction (MI) patients remain at high risk for recurrent events. Cholesterol efflux, mediated by apolipoprotein A-I, removes excess cholesterol from atherosclerotic plaque and transports it to the liver for excretion. Impaired cholesterol efflux is associated with higher cardiovascular (CV) event rates among both patients with stable coronary artery disease and recent MI. CSL112, a novel intravenous formulation of apolipoprotein A-I (human) derived from human plasma, increases cholesterol efflux capacity. AEGIS-II is a phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group trial investigating the efficacy and safety of CSL112 compared to placebo among high-risk acute MI participants. Eligibility criteria include age ≥ 18 years with type 1 (spontaneous) MI, evidence of multivessel stable coronary artery disease, and presence of diabetes requiring pharmacotherapy, or ≥2 of the following: age ≥ 65 years, prior MI, or peripheral artery disease. A target sample of 17,400 participants will be randomized 1:1 to receive 4 weekly infusions of CSL112 6 g or placebo, initiated prior to or on the day of discharge and within 5 days of first medical contact. The primary outcome is the time to first occurrence of the composite of CV death, MI, or stroke through 90 days. Key secondary outcomes include the total number of hospitalizations for coronary, cerebral, or peripheral ischemia through 90 days and time to first occurrence of the composite primary outcome through 180 and 365 days. AEGIS-II will be the first trial to formally test whether enhancing cholesterol efflux can reduce the rate of recurrent major adverse CV events.

Pharmacometric analyses to characterize the effect of CSL112 on apolipoprotein A-I and cholesterol efflux capacity in acute myocardial infarction patients

AIMS

To characterize relationships between apolipoprotein A-I (apoA-I) exposure and cholesterol efflux capacity (CEC) and covariate effects following CSL112 (apoA-I [human]) administration in an integrated population including acute myocardial infarction (AMI) patients.

METHODS

A pharmacometric analysis utilized data from seven clinical trials, including patients with AMI, subjects with renal impairment and healthy subjects. A population pharmacokinetic (PK) analysis was performed to relate CSL112 doses to changes in apoA-I plasma concentrations. Covariate analysis was conducted to identify sources of variability in apoA-I exposure. Exposure-response modeling was conducted to describe the relationship between apoA-I exposure and total or ATP binding cassette transporter A1-(ABCA1)-dependent CEC and to identify clinical predictors of CEC.

RESULTS

A two-compartment model described apoA-I PK. ApoA-I clearance was slightly lower in subjects with AMI, whereas baseline apoA-I was marginally higher in female and Japanese subjects. Covariate effects on apoA-I exposure were in the order of 10% and thus not clinically relevant. The relationships between apoA-I exposure and CECs were described by nonlinear models. Simulations showed CEC elevation resulting from apoA-I exposure increment was comparable in AMI and non-AMI subjects; no covariate had clinically meaningful effects on CEC. Simulations also demonstrated that CEC in patients with AMI post 6 g CSL112 dosing was substantially elevated compared to placebo and lower dose levels.

CONCLUSIONS

The model-based exposure-response analysis demonstrated, irrespective of body weight, sex and race, that fixed 6 g CSL112 dosing causes a desired CEC elevation, which may benefit AMI patients by potentially reducing early recurrent cardiovascular event risk.

Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

Aims 

The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI.

Methods and results 

Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI.

Conclusion 

After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.

Standardized classification and framework for reporting, interpreting, and analysing medication non-adherence in cardiovascular clinical trials: a consensus report from the Non-adherence Academic Research Consortium (NARC)

Non-adherence has been well recognized for years to be a common issue that significantly impacts clinical outcomes and health care costs. Medication adherence is remarkably low even in the controlled environment of clinical trials where it has potentially complex major implications. Collection of non-adherence data diverge markedly among cardiovascular randomized trials and, even where collected, is rarely incorporated in the statistical analysis to test the consistency of the primary endpoint(s). The imprecision introduced by the inconsistent assessment of non-adherence in clinical trials might confound the estimate of the calculated efficacy of the study drug. Hence, clinical trials may not accurately answer the scientific question posed by regulators, who seek an accurate estimate of the true efficacy and safety of treatment, or the question posed by payers, who want a reliable estimate of the effectiveness of treatment in the marketplace after approval. The Non-adherence Academic Research Consortium is a collaboration among leading academic research organizations, representatives from the U.S. Food and Drug Administration and physician-scientists from the USA and Europe. One in-person meeting was held in Madrid, Spain, culminating in a document describing consensus recommendations for reporting, collecting, and analysing adherence endpoints across clinical trials. The adoption of these recommendations will afford robustness and consistency in the comparative safety and effectiveness evaluation of investigational drugs from early development to post-marketing approval studies. These principles may be useful for regulatory assessment, as well as for monitoring local and regional outcomes to guide quality improvement initiatives.

Frequency, Regional Variation, and Predictors of Undetermined Cause of Death in Cardiometabolic Clinical Trials: A Pooled Analysis of 9259 Deaths in 9 Trials

BACKGROUND

Modern cardiometabolic clinical trials often include cardiovascular death as a component of a composite primary outcome, requiring central adjudication by a clinical events committee to classify cause of death. However, sometimes the cause of death cannot be determined from available data. The US Food and Drug Administration has indicated that this circumstance should occur only rarely, but its prevalence has not been formally assessed.

METHODS

Data from 9 global clinical trials (2009-2017) with long-term follow-up and blinded, centrally adjudicated cause of death were used to calculate the proportion of deaths attributed to cardiovascular, noncardiovascular, or undetermined causes by therapeutic area (diabetes mellitus/pre-diabetes mellitus, stable atherosclerosis, atrial fibrillation, and acute coronary syndrome), region of patient enrollment, and year of trial manuscript publication. Patient- and trial-level variables associated with undetermined cause of death were identified using a logistic model.

RESULTS

Across 127 049 enrolled participants from 9 trials, there were 9259 centrally adjudicated deaths: 5012 (54.1%) attributable to cardiovascular causes, 2800 (30.2%) attributable to noncardiovascular causes, and 1447 (15.6%) attributable to undetermined causes. There was variability in the proportion of deaths ascribed to undetermined causes by trial therapeutic area, region of enrollment, and year of trial manuscript publication. On multivariable analysis, acute coronary syndrome or atrial fibrillation trial (versus atherosclerotic vascular disease or diabetes mellitus/pre-diabetes mellitus), longer time from enrollment to death, more recent trial manuscript publication year, enrollment in North America (versus Western Europe), female sex, and older age were associated with greater likelihood of death of undetermined cause.

CONCLUSIONS

In 9 cardiometabolic clinical trials with long-term follow-up, approximately 16% of deaths had undetermined causes. This provides a baseline for quality assessment of clinical trials and informs operational efforts to potentially reduce the frequency of undetermined deaths in future clinical research.

Stroke Outcomes With Vorapaxar Versus Placebo in Patients With Acute Coronary Syndromes: Insights From the TRACER Trial

Background

Vorapaxar, a protease‐activated receptor‐1 antagonist, is approved for secondary prevention of cardiovascular events but is associated with increased intracranial hemorrhage.

Methods and Results

TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) was a trial of vorapaxar versus placebo among patients with acute coronary syndrome. Strokes were adjudicated by a central events committee. Of 12 944 patients, 199 (1.5%) had ≥1 stroke during the study period (median follow‐up, 477 days). Four patients had a single stroke of unknown type; 195 patients had ≥1 stroke classified as hemorrhagic or nonhemorrhagic (165 nonhemorrhagic, 28 hemorrhagic, and 2 both). Strokes occurred in 96 of 6473 patients (1.5%) assigned vorapaxar and 103 of 6471 patients (1.6%) assigned placebo. Kaplan‐Meier incidence of stroke for vorapaxar versus placebo was higher for hemorrhagic stroke (0.45% versus 0.14% [hazard ratio, 2.74; 95% confidence interval, 1.22–6.15]), lower but not significantly different for nonhemorrhagic stroke (1.53% versus 1.98% at 2 years [hazard ratio, 0.79; 95% confidence interval, 0.58–1.07]), and similar for stroke overall (1.93% versus 2.13% at 2 years [hazard ratio, 0.94; 95% confidence interval, 0.71–1.24]).

Conclusions

Stroke occurred in <2% of patients. Vorapaxar‐assigned patients had increased hemorrhagic stroke but a nonsignificant trend toward lower nonhemorrhagic stroke. Overall stroke frequency was similar with vorapaxar versus placebo.

Prognostic and Practical Validation of Current Definitions of Myocardial Infarction Associated With Percutaneous Coronary Intervention

OBJECTIVES

In 13,038 patients with non-ST-segment elevation acute coronary syndrome undergoing index percutaneous coronary intervention (PCI) in the EARLY ACS (Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome) and TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) trials, the relationship between PCI-related myocardial infarction (MI) and 1-year mortality was assessed.

BACKGROUND

The definition of PCI-related MI is controversial. The third universal definition of PCI-related MI requires cardiac troponin >5 times the 99th percentile of the normal reference limit from a stable or falling baseline and PCI-related clinical or angiographic complications. The definition from the Society for Cardiovascular Angiography and Interventions (SCAI) requires creatine kinase-MB elevation >10 times the upper limit of normal (or 5 times if new electrocardiographic Q waves are present). Implications of these definitions on prognosis, prevalence, and implementation are not established.

METHODS

In our cohort of patients undergoing PCI, PCI-related MIs were classified using the third universal type 4a MI definition and SCAI criteria. In the subgroup of patients included in the angiographic core laboratory (ACL) substudy of EARLY ACS (n = 1,401) local investigator- versus ACL-reported angiographic complications were compared.

RESULTS

Altogether, 2.0% of patients met third universal definition of PCI-related MI criteria, and 1.2% met SCAI criteria. One-year mortality was 3.3% with the third universal definition (hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.10) and 5.3% with SCAI criteria (hazard ratio: 2.79; 95% confidence interval: 1.69 to 4.58; p < 0.001). Agreement between ACL and local investigators in detecting angiographic complications during PCI was overall moderate (κ = 0.53).

CONCLUSIONS

The third universal definition of MI and the SCAI definition were both associated with significant risk for mortality at 1 year. Suboptimal concordance was observed between ACL and local investigators in identifying patients with PCI complications detected on angiography. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRA·CER] [Study P04736]; NCT00527943; EARLY ACS: Early Glycoprotein IIb/IIIa Inhibition in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome [Study P03684AM2]; NCT00089895).

Effect of Alirocumab on Mortality After Acute Coronary Syndromes

Supplemental Digital Content is available in the text.

Background:

Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome.

Methods:

ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death.

Results:

Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; P_interaction=0.007). In the alirocumab group, all-cause death declined with achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend).

Conclusions:

Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402.

The CSL112-2001 trial: Safety and tolerability of multiple doses of CSL112 (apolipoprotein A-I [human]), an intravenous formulation of plasma-derived apolipoprotein A-I, among subjects with moderate renal impairment after acute myocardial infarction

BACKGROUND

CSL112 (apolipoprotein A-I [human]) is a plasma-derived apolipoprotein A-I developed for early reduction of cardiovascular risk following an acute myocardial infarction (AMI). The safety of CSL112 among AMI subjects with moderate, stage 3 chronic kidney disease (CKD) is unknown.

METHODS

CSL112_2001, a multicenter, placebo-controlled, parallel-group, double-blind, randomized phase 2 trial, enrolled patients with moderate CKD within 7 days following AMI. Enrollment was stratified on the basis of estimated glomerular filtration rate and presence of diabetes requiring treatment. Patients were randomized in a 2:1 ratio to receive 4 weekly infusions of CSL112 6 g or placebo. The co-primary safety end points were renal serious adverse events (SAEs) and acute kidney injury, defined as an increase ≥26.5 μmol/L in baseline serum creatinine for more than 24 hours, during the treatment period.

RESULTS

A total of 83 patients were randomized (55 CSL112 vs 28 placebo). No increase in renal SAEs was observed in the CSL112 group compared with placebo (CSL112 = 1 [1.9%], placebo = 4 [14.3%]). Similarly, no increase in acute kidney injury events was observed (CSL112 = 2 [4.0%], placebo = 4 [14.3%]). Rates of other SAEs were similar between groups. CSL112 administration resulted in increases in ApoA-I and cholesterol efflux similar to those observed in patients with AMI and normal renal function or stage 2 CKD enrolled in the ApoA-I Event Reducing in Ischemic Syndromes I trial.

CONCLUSIONS

These results demonstrate the acceptable safety of the 6-g dose of CSL112 among AMI subjects with moderate stage 3 CKD and support inclusion of these patients in a phase 3 cardiovascular outcomes trial powered to assess efficacy.

Alirocumab and Cardiovascular Outcomes after Acute Coronary Syndrome

BACKGROUND

Patients who have had an acute coronary syndrome are at high risk for recurrent ischemic cardiovascular events. We sought to determine whether alirocumab, a human monoclonal antibody to proprotein convertase subtilisin-kexin type 9 (PCSK9), would improve cardiovascular outcomes after an acute coronary syndrome in patients receiving high-intensity statin therapy.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled trial involving 18,924 patients who had an acute coronary syndrome 1 to 12 months earlier, had a low-density lipoprotein (LDL) cholesterol level of at least 70 mg per deciliter (1.8 mmol per liter), a non-high-density lipoprotein cholesterol level of at least 100 mg per deciliter (2.6 mmol per liter), or an apolipoprotein B level of at least 80 mg per deciliter, and were receiving statin therapy at a high-intensity dose or at the maximum tolerated dose. Patients were randomly assigned to receive alirocumab subcutaneously at a dose of 75 mg (9462 patients) or matching placebo (9462 patients) every 2 weeks. The dose of alirocumab was adjusted under blinded conditions to target an LDL cholesterol level of 25 to 50 mg per deciliter (0.6 to 1.3 mmol per liter). The primary end point was a composite of death from coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal ischemic stroke, or unstable angina requiring hospitalization.

RESULTS

The median duration of follow-up was 2.8 years. A composite primary end-point event occurred in 903 patients (9.5%) in the alirocumab group and in 1052 patients (11.1%) in the placebo group (hazard ratio, 0.85; 95% confidence interval [CI], 0.78 to 0.93; P<0.001). A total of 334 patients (3.5%) in the alirocumab group and 392 patients (4.1%) in the placebo group died (hazard ratio, 0.85; 95% CI, 0.73 to 0.98). The absolute benefit of alirocumab with respect to the composite primary end point was greater among patients who had a baseline LDL cholesterol level of 100 mg or more per deciliter than among patients who had a lower baseline level. The incidence of adverse events was similar in the two groups, with the exception of local injection-site reactions (3.8% in the alirocumab group vs. 2.1% in the placebo group).

CONCLUSIONS

Among patients who had a previous acute coronary syndrome and who were receiving high-intensity statin therapy, the risk of recurrent ischemic cardiovascular events was lower among those who received alirocumab than among those who received placebo. (Funded by Sanofi and Regeneron Pharmaceuticals; ODYSSEY OUTCOMES ClinicalTrials.gov number, NCT01663402 .).

Evaluation of potential antiplatelet effects of CSL112 (Apolipoprotein A-I [Human]) in patients with atherosclerosis: results from a phase 2a study

CSL112 (Apolipoprotein A-I [Human]), an infusible, plasma-derived apolipoprotein A-I, is being developed to reduce cardiovascular events following acute myocardial infarction (AMI). A predecessor compound (CSL111) demonstrated a potential antiplatelet effect. A phase 2a multicentre, randomised, single-ascending dose study in patients with stable atherosclerotic disease receiving dual antiplatelet therapy (DAPT) assessed the potential additive effects of CSL112 administration on platelet function and increase bleeding risk in the subacute period after AMI. Patients (n = 44) on aspirin (75–325 mg/day) and either clopidogrel (75 mg/day, n = 37) or prasugrel (10 mg/day, n = 7) for > 30 days alongside standard-of-care therapy were randomised to a single dose of placebo or CSL112: 1.7, 3.4, or 6.8 g. Light transmission aggregometry was used to assess platelet aggregation in response to 2 mM arachidonic acid, 5 and 20 µM adenosine diphosphate, and 4 µg/mL collagen, pre-dose (baseline) and up to 48 h post-dosing. Compared to placebo, CSL112 had no clinically meaningful time- or dose-dependent effects on maximum platelet aggregation in response to any agonist, by either dose or renal function subgroup (p > 0.05). Coagulation parameters showed little variation over time or between treatment groups (p > 0.05). CSL112, when co-administered with standard DAPT, did not significantly influence platelet aggregation in response to agonists and is, therefore, not expected to significantly increase bleeding risk when administered with antiplatelet therapies.

Effects of genetic variation in protease activated receptor 4 after an acute coronary syndrome: Analysis from the TRACER trial

Variation in platelet response to thrombin may affect the safety and efficacy of PAR antagonism. The Thr120 variant of the common single nucleotide polymorphism (SNP) rs773902 in the protease-activated receptor (PAR) 4 gene is associated with higher platelet aggregation compared to the Ala120 variant. We investigated the relationship between the rs773902 SNP with major bleeding and ischemic events, safety, and efficacy of PAR1 inhibition in 6177 NSTE ACS patients in the TRACER trial. There was a lower rate of GUSTO moderate/severe bleeding in patients with the Thr120 variant. The difference was driven by a lower rate in the smaller homozygous group (recessive model, HR 0.13 [0.02-0.92] P = 0.042). No significant differences were observed in the ischemic outcomes. The excess in bleeding observed with PAR1 inhibition was attenuated in patients with the Thr120 variant, but the interactions were not statistically significant. In summary, lower major bleeding rates were observed in the overall TRACER cohort with the hyperreactive PAR4 Thr120 variant. The increase in bleeding with vorapaxar was attenuated with the Thr120 variant, but we could not demonstrate an interaction with PAR1 inhibition. These findings warrant further exploration, including those of African ancestry where the A allele (Thr120) frequency is ~65%.

Incidence, timing, and type of first and recurrent ischemic events in patients with and without peripheral artery disease after an acute coronary syndrome

BACKGROUND

Patients with peripheral artery disease (PAD) are known to have an increased risk of ischemic cardiovascular events. However, the influence of concomitant PAD on first and subsequent recurrent ischemic events after an acute coronary syndrome (ACS) remains poorly characterized.

METHODS

We analyzed the combined data set from 4 randomized trials (PLATO, APPRAISE-2, TRA-CER, and TRILOGY ACS) in ACS for a follow-up length of 1 year. Using multivariable regression, we examined the association between PAD and major adverse cardiovascular events, a composite of cardiovascular death, myocardial infarction, and stroke. Among patients with a nonfatal first event, we evaluated the incidence and type of a second recurrent event.

RESULTS

A total of 4,098 of 48,094 (8.5%) post-ACS patients had a history of PAD. The unadjusted frequency of major adverse cardiovascular events was 2-fold higher in patients with PAD (14.3% vs 7.5%) over a median (25th-75th) follow-up of 353 (223-365) days with an adjusted hazard ratio of 1.63 (95% CI: 1.48-1.78; P < .001). The frequency of recurrent ischemic events among those patients with a first, nonfatal event was higher among those with PAD (40.0% vs 27.7%). The relative frequency of each event type (cardiovascular death, noncardiovascular death, myocardial infarction, or stroke) within first and subsequent ischemic events was similar regardless of PAD status at baseline.

CONCLUSIONS

Patients with PAD have a significantly higher risk of first and recurrent ischemic events in the post-ACS setting. These findings highlight the opportunity for improved treatments in patients with PAD who experience an ACS.

Clinical features and outcomes of patients with type 2 myocardial infarction: Insights from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial

BACKGROUND

Type 2 myocardial infarction (MI) is characterized by an imbalance between myocardial blood supply and demand, leading to myocardial ischemia without coronary plaque rupture, but its diagnosis is challenging.

METHODS

In the TRACER trial, patients with non-ST-segment elevation acute coronary syndromes were included. We aimed to describe provoking factors, cardiac biomarker profiles, treatment patterns, and clinical outcomes of patients with type 2 MIs. MI events during trial follow-up were adjudicated by an independent clinical events classification committee (CEC) and were classified according to the Third Universal Definition of MI. Using available source documents retrieved as part of the CEC process, we performed a retrospective chart abstraction to collect details on the type 2 MIs. Cox regression models were used to explore the association between MI type (type 1 or type 2) and cardiovascular death.

RESULTS

Overall, 10.3% (n=1327) of TRACER participants had a total of 1579 adjudicated MIs during a median follow-up of 502 days (25th and 75th percentiles [IQR] 349-667). Of all MIs, 5.2% (n=82) were CEC-adjudicated type 2 MIs, occurring in 76 patients. The incidence of type 2 MI was higher in the first month following randomization, after which the distribution became more scattered. The most frequent potential provoking factors for type 2 MIs were tachyarrhythmias (38.2%), anemia/bleeding (21.1%), hypotension/shock (14.5%), and hypertensive emergencies (11.8%). Overall, 36.3% had a troponin increase >10× the upper limit of normal. Coronary angiography was performed in 22.4% (n=17) of patients during hospitalizations due to type 2 MIs. The hazard of cardiovascular death was numerically higher following type 2 MI (vs. no MI, adj. HR 11.82, 95% CI 5.71-24.46; P<.0001) than that of type 1 MI (vs. no MI, adj. HR 8.90, 95% CI 6.93-11.43; P<.0001).

CONCLUSIONS

Type 2 MIs were more prevalent in the first month after ACS, were characterized by the presence of triggers and infrequent use of an invasive strategy, and were associated with a high risk of death. Further efforts are needed to better define the role and implications of type 2 MI in both clinical practice and research.

Obesity, Diabetes, and Acute Coronary Syndrome: Differences Between Asians and Whites

BACKGROUND

Most diabetes and cardiovascular studies have been conducted in white patients, with data being extrapolated to other population groups.

METHODS

For this analysis, patient-level data were extracted from 5 randomized clinical trials in patients with acute coronary syndrome; we compared obesity levels between Asian and white populations, stratified by diabetes status. By using an adjusted Cox proportional hazards model, hazard ratios (HRs) for cardiovascular outcomes after an acute coronary syndrome were determined.

RESULTS

We identified 49,224 patient records from the 5 trials, with 3176 Asians and 46,048 whites. Whites with diabetes had higher body mass index values than those without diabetes (median 29.3 vs 27.2 kg/m²; P < .0001), whereas Asians with diabetes and without diabetes had similar body mass index (24.7 vs 24.2 kg/m²). Asians with diabetes (HR, 1.63; 95% confidence interval [CI], 1.32-2.02), whites with diabetes (HR, 1.15; 95% CI, 1.06-1.25), and Asians without diabetes (HR, 1.36; 95% CI, 1.14-1.64) had higher rates of the composite of death, myocardial infarction, or stroke at 30 days than whites without diabetes. Asians with diabetes (HR, 1.84; 95% CI, 1.47-2.31), whites with diabetes (HR, 1.47; 95% CI, 1.33-1.62), and Asians without diabetes (HR, 1.38; 95% CI, 1.11-1.73) had higher rates of death at 1 year compared with whites without diabetes. There were no significant interactions between race and diabetes for ischemic outcomes.

CONCLUSIONS

Although Asians with diabetes and acute coronary syndrome are less likely to be obese than their white counterparts, their risk for death or recurrent ischemic events was not lower.

Validation of BARC Bleeding Criteria in Patients With Acute Coronary Syndromes: The TRACER Trial

BACKGROUND

The Bleeding Academic Research Consortium (BARC) scale has been proposed to standardize bleeding endpoint definitions and reporting in cardiovascular trials. Validation in large cohorts of patients is needed.

OBJECTIVES

This study sought to investigate the relationship between BARC-classified bleeding and mortality and compared its prognostic value against 2 validated bleeding scales: TIMI (Thrombolysis In Myocardial Infarction) and GUSTO (Global Use of Strategies to Open Occluded Arteries).

METHODS

We analyzed bleeding in 12,944 patients with acute coronary syndromes without ST-segment elevation, with or without early invasive strategy. The main outcome measure was all-cause death.

RESULTS

During follow-up (median: 502 days), noncoronary artery bypass graft (CABG) bleeding occurred in 1,998 (15.4%) patients according to BARC (grades 2, 3, or 5), 484 (3.7%) patients according to TIMI minor/major, and 514 (4.0%) patients according to GUSTO moderate/severe criteria. CABG-related bleeding (BARC 4) occurred in 155 (1.2%) patients. Patients with BARC (2, 3, or 4) bleeding had a significant increase in risk of death versus patients without bleeding (BARC 0 or 1); the hazard was highest in the 30 days after bleeding (hazard ratio: 7.35; 95% confidence interval: 5.59 to 9.68; p < 0.0001) and remained significant up to 1 year. The hazard of mortality increased progressively with non-CABG BARC grades. BARC 4 bleeds were significantly associated with mortality within 30 days (hazard ratio: 10.05; 95% confidence interval: 5.41 to 18.69; p < 0.0001), but not thereafter. Inclusion of BARC (2, 3, or 4) bleeding in the 1-year mortality model with baseline characteristics improved it to an extent comparable to TIMI minor/major and GUSTO moderate/severe bleeding.

CONCLUSIONS

In patients with acute coronary syndromes without ST-segment elevation, bleeding assessed with the BARC scale was significantly associated with risk of subsequent death up to 1 year after the event and risk of mortality increased gradually with higher BARC grades. Our results support adoption of the BARC bleeding scale in ACS clinical trials. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRACER] [Study P04736]; NCT00527943).

Differential occurrence, profile, and impact of first recurrent cardiovascular events after an acute coronary syndrome

OBJECTIVE

Acute coronary syndrome (ACS) trials typically use a composite primary outcome (myocardial infarction [MI], stroke, or cardiovascular death), but differential patient characteristics, timing, and consequences associated with individual component end points as first events have not been well studied. We compared patient characteristics and prognostic significance associated with first cardiovascular events in the post-ACS setting for initially stabilized patients.

METHODS

We combined patient-level data from 4 trials of post-ACS antithrombotic therapies (PLATO, APPRAISE-2, TRACER, and TRILOGY ACS) to characterize the timing of and characteristics associated with first cardiovascular events (MI, stroke, or cardiovascular death). Landmark analysis at 7 days after index ACS presentation was used to focus on spontaneous, postdischarge events that were not confounded by in-hospital procedural complications. Using a competing risk framework, we tested for differential associations between prespecified covariates and the occurrence of nonfatal stroke vs MI as the first event, and we examined subsequent events after the first nonfatal event.

RESULTS

Among 46,694 patients with a median follow-up of 358 (25th, 75th percentiles 262, 486) days, a first ischemic event occurred in 4,307 patients (9.2%) as follows: MI in 5.8% (n = 2,690), stroke in 1.0% (n = 477), and cardiovascular death in 2.4% (n = 1,140). Older age, prior stroke/transient ischemic attack, prior atrial fibrillation, and higher diastolic blood pressure were associated with a significantly greater risk of stroke vs MI, whereas prior percutaneous coronary intervention was associated with a greater risk of MI vs stroke. Second events occurred in 32% of those with a first nonfatal stroke at a median of 13 (3, 59) days after the first event and in 32% of those with a first nonfatal MI at a median of 35 (5, 137) days after the first event. The most common second event was a recurrent MI among those with MI as the first event and cardiovascular death among those with stroke as the first event.

CONCLUSIONS

Approximately 9% of patients experienced a first cardiovascular event in the post-ACS setting during a median follow-up of 1 year. Although the profile and prognostic implications of stroke vs MI as the first nonfatal event differ substantially, approximately one-third of these patients experienced a second event, typically soon after the first event. These findings have implications for improving post-ACS care and influencing the design of future cardiovascular trials.

An examination of the relationship between serum uric acid level, a clinical history of gout, and cardiovascular outcomes among patients with acute coronary syndrome

BACKGROUND

Studies have suggested a relationship between higher baseline serum uric acid (sUA) levels and an elevated risk of subsequent ischemic cardiovascular outcomes among acute coronary syndrome (ACS) patients; this relationship may be modified by a clinical history of gout and has not been studied in large patient cohorts. We sought to understand the effect of sUA and gout on ACS outcomes.

METHODS

Using PLATO and TRACER data on 27,959 ACS patients, we evaluated baseline sUA levels in relation to a composite of cardiovascular death, myocardial infarction (MI), or stroke. We assessed interaction terms to determine if a baseline clinical diagnosis of gout modified this putative relationship; 46% (n=12,882) had sUA levels elevated >6.0 mg/dL.

RESULTS

Patients with elevated levels were more often male with a history of prior MI, diabetes, and heart failure compared with those with sUA <6.0 mg/dL. The unadjusted risk of the composite endpoint increased with corresponding elevations in sUA levels (per 1 mg/dL increase) (HR=1.23 [95% CI: 1.20-1.26]) above the statistical inflection point of 5.0 mg/dL. After adjustment, the association between sUA level and the composite outcome remained significant (HR=1.07 [95% CI: 1.04-1.10]), and baseline gout did not modify this relationship.

CONCLUSIONS

In patients with ACS, increasing levels of sUA are associated with an elevated risk of cardiovascular events, regardless of a clinical diagnosis of gout. Further investigation is warranted to determine the mechanism behind this relationship and to delineate whether sUA is an appropriate therapeutic target to reduce cardiovascular risk.

Predicting the risk of bleeding during dual antiplatelet therapy after acute coronary syndromes

OBJECTIVES

Dual antiplatelet therapy (DAPT) with aspirin + a P2Y12 inhibitor is recommended for at least 12 months for patients with acute coronary syndrome (ACS), with shorter durations considered for patients with increased bleeding risk. However, there are no decision support tools available to predict an individual patient's bleeding risk during DAPT treatment in the post-ACS setting.

METHODS

To develop a longitudinal bleeding risk prediction model, we analy sed 9240 patients with unstable angina/non-ST segment elevation myocardial infarction (NSTEMI) from the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes (TRILOGY ACS) trial, who were managed without revasculari sation and treated with DAPT for a median of 14.8 months.

RESULTS

We identified 10 significant baseline predictors of non-coronary artery bypass grafting (CABG)-related Global Use of Strategies to Open Occluded Arteries (GUSTO) severe/life-threatening/moderate bleeding: age, sex, weight, NSTEMI (vs unstable angina), angiography performed before randomi sation, prior peptic ulcer disease, creatinine, systolic blood pressure, haemoglobin and treatment with beta-blocker. The five significant baseline predictors of Thrombolysis In Myocardial Infarction (TIMI) major or minor bleeding included age, sex, angiography performed before randomi sation, creatinine and haemoglobin. The models showed good predictive accuracy with Therneau's C-indices: 0.78 (SE = 0.024) for the GUSTO model and 0.67 (SE = 0.023) for the TIMI model. Internal validation with bootstrapping gave similar C-indices of 0.77 and 0.65, respectively. External validation demonstrated an attenuated C-index for the GUSTO model (0.69) but not the TIMI model (0.68).

CONCLUSIONS

Longitudinal bleeding risks during treatment with DAPT in patients with ACS can be reliably predicted using selected baseline characteristics. The TRILOGY ACS bleeding models can inform risk -benefit considerations regarding the duration of DAPT following ACS.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: https://clinicaltrials.gov/ct2/show/NCT00699998.

Trade-off of myocardial infarction vs. bleeding types on mortality after acute coronary syndrome: lessons from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) randomized trial

AIMS

Dual antiplatelet therapy reduces non-fatal ischaemic events after acute coronary syndrome (ACS) but increases bleeding to a similar extent. We sought to determine the prognostic impact of myocardial infarction (MI) vs. bleeding during an extended follow-up period to gain insight into the trade-off between efficacy and safety among patients after ACS.

METHODS AND RESULTS

In 12 944 patients with non-ST-segment elevation ACS from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial, we investigated the relative impact of MI and bleeding occurring >30 days post-ACS and subsequent all-cause mortality. Bleeding was graded according to Bleeding Academic Research Consortium (BARC) criteria. MI was associated with a five-fold increase in mortality. BARC type 2 and 3, but not type 1, bleeding had a significant impact on mortality. MI was associated with a greater risk of mortality compared with BARC 2 [relative risk (RR) 3.5; 95% confidence interval (CI) 2.08-4.77; P < 0.001] and BARC 3a bleeding (RR 2.23; 95% CI 1.36-3.64; P = 0.001), and a risk similar to BARC 3b bleeding (RR 1.37; 95% CI 0.81-2.30; P = 0.242). Risk of death after MI was significantly lower than after BARC 3c bleeding (RR 0.22; 95% CI 0.13-0.36; P < 0.001). MI and bleeding had similar time-associations with mortality, which remained significant for several months, still being higher early after the event.

CONCLUSION

In patients treated with antiplatelet therapy after ACS, both MI and bleeding significantly impacted mortality with similar time-dependency. Although BARC 2 and 3a bleeding were less prognostic for death than MI, the risk of mortality was equivalent between BARC 3b bleeding and MI, and was higher following BARC 3c bleeding.

Consensus or Controversy?: Evolution of Criteria for Myocardial Infarction After Percutaneous Coronary Intervention

BACKGROUND

The definition and the clinical implications of myocardial infarction (MI) occurring in the setting of percutaneous coronary intervention have been subjects of unresolved controversy. As a result of the use of more sensitive diagnostic tools such as cardiac troponin, the expanding evidence, and the ensuing debate, the definition of procedural MI (pMI) has evolved, leading to several revisions, different proposed definitions, and lack of standardization in randomized clinical trials.

CONTENT

In this review, we will describe the key clinical data on cardiac biomarkers, creatine kinase isoenzyme MB and cTn, in the setting of percutaneous coronary intervention and the main issues that have lead to various consensus documents with a proposed definition of pMI. We will focus on the rationale of the current “Third Universal Definition of Myocardial Infarction” and of the alternative approach proposed by the Society for Cardiovascular Angiography and Interventions.

SUMMARY

The definition of pMI is an evolving field where the Third Universal MI definition represents the best attempt to date to incorporate available evidence along with scientific and clinical judgment into criteria to ensure adequate specificity in the diagnosis and the relevant prognostic significance, while trying to maintain sensitivity. Questions on the recommended criteria and their practical implementation remain, but the Third Universal definition document represents an important milestone toward a better standardization and enhanced consensus on the pMI definition.

Lack of Concordance Between Local Investigators, Angiographic Core Laboratory, and Clinical Event Committee in the Assessment of Stent Thrombosis: Results From the TRACER Angiographic Substudy

BACKGROUND

Stent thrombosis (ST) is an important end point in cardiovascular clinical trials. Adjudication is traditionally based on clinical event committee (CEC) review of case report forms and source documentation rather than angiograms. However, the degree to which this method of adjudication is concordant with the review of independent angiographic core laboratories (ACLs) has not been studied. This report represents the first assessment of variability between local investigators (LIs), a CEC, and an ACL.

METHODS AND RESULTS

Serial angiograms of 329 patients with acute coronary syndrome without ST-segment-elevation who underwent percutaneous coronary intervention at entry in the Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Particpants With Acute Coronary Syndrome (TRACER) and who met criteria for possible ST subsequent to the index event were reviewed by an ACL. The ACL was blinded to the assessment by both LIs and the CEC regarding the presence or absence of ST. CEC adjudication was based on Academic Research Consortium definitions of ST, using case report form data and source documents, including catheterization laboratory reports. The ACL, CEC, and LIs agreed on the presence or absence of ST in 52.9% events (κ=0.32; 95% confidence interval, 0.26-0.39). The ACL and CEC agreed on 82.7% of events (κ=0.57; 95% confidence interval, 0.47-0.67); the ACL and LIs agreed on 61.1% of events (κ=0.25; 95% confidence interval, 0.16-0.34); and the CEC and LIs agreed on 62% of events (κ=0.28; 95% confidence interval, 0.21-0.36).

CONCLUSIONS

ST reporting by an ACL, a CEC, and LIs is discordant. The assessment of ST is more often detected by direct review of angiograms by an ACL.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00527943.

Protease-Activated Receptor-1 Antagonists Post-Percutaneous Coronary Intervention

Thrombin is a potent platelet agonist, and protease-activated receptor-1 (PAR-1) is the main thrombin receptor in human platelets and thrombin. PAR-1 antagonism has attracted interest as a potential therapeutic target to reduce atherothrombotic events in patients with atherosclerotic disease, especially coronary artery disease. In this review, the author describes the rationale of PAR-1 antagonism for the reduction of atherothrombotic events and reviews the key phase 3 trial results, with special attention to analyses in percutaneous coronary intervention patients.

Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction: The AEGIS-I Trial (ApoA-I Event Reducing in Ischemic Syndromes I)

BACKGROUND

Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein-mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction.

METHODS

The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy).

RESULTS

A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events among the groups was similar.

CONCLUSIONS

Among patients with acute myocardial infarction, 4 weekly infusions of CSL112 are feasible, well tolerated, and not associated with any significant alterations in liver or kidney function or other safety concern. The ability of CSL112 to acutely enhance cholesterol efflux was confirmed. The potential benefit of CSL112 to reduce major adverse cardiovascular events needs to be assessed in an adequately powered phase 3 trial.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT02108262.

Rationale and design of Apo-I Event Reduction in Ischemic Syndromes I (AEGIS-I): A phase 2b, randomized, placebo-controlled, dose-ranging trial to investigate the safety and tolerability of CSL112, a reconstituted, infusible, human apoA-I, after acute myocardial infarction

BACKGROUND

Despite aggressive pharmacotherapy and stenting, there is a residual risk of major adverse cardiovascular events among patients with acute coronary syndrome. High-density lipoprotein (HDL) has been a major target for secondary acute coronary syndrome prevention; however, a better understanding of the physiologic function of HDL has demonstrated that a high cholesterol efflux capacity, rather than high HDL concentrations alone, may be critical to improving outcomes. CSL112, a reconstituted, infusible human apolipoprotein A-I, has been demonstrated to increase cholesterol efflux capacity and to have a protective effect in experimental models of atherosclerotic cardiovascular disease.

DESIGN

The AEGIS-I trial (ClinicalTrials.govNCT02108262) is a phase 2b, multicenter, randomized, placebo-controlled, dose-ranging clinical trial to evaluate the hepatic and renal safety of multiple administrations of 2 doses of CSL112 among subjects with acute myocardial infarction (AMI). Approximately 1,200 subjects (400 per treatment group) with either normal renal function or mild renal impairment will be enrolled up to 7 days after an AMI and will be stratified by renal function and randomized in a 1:1:1 ratio to either 1 of 2 doses of CSL112 (either 2 g or 6 g) or placebo as a weekly 2-hour infusion over the course of 4 consecutive weeks. The coprimary safety endpoints will be the incidence of hepatic and renal toxicity, defined as either confirmed ALT >3 × ULN, total bilirubin >2 × ULN, serum creatinine ≥1.5×baseline value, or a new requirement for renal replacement therapy through the end of the active treatment period.

SUMMARY

The AEGIS-I trial will characterize the safety profile of CSL112, a reconstituted formulation of apolipoprotein A-I, and will assess if administration to patients with a recent AMI is associated with a clinically significant alteration in either liver or kidney function when compared with placebo.

Albuminuria and cardiovascular events in patients with acute coronary syndromes: Results from the TRACER trial

BACKGROUND

Albuminuria is associated with cardiovascular (CV) outcomes. We evaluated albuminuria, alone and in combination with estimated glomerular filtration rate (eGFR), as a predictor of mortality and CV morbidity in 12,944 patients with non-ST-segment elevation acute coronary syndromes.

METHODS

Baseline serum creatinine and urinary dipsticks were obtained, with albuminuria stratified into no/trace albuminuria, microalbuminuria (≥30 but <300 mg/dL), or macroalbuminuria (≥300 mg/dL). Kaplan-Meier rates and proportional Cox hazards models of CV death, overall mortality, CV death or myocardial infarction (MI), and bleeding were calculated. Incidence of acute kidney injury, identified by adverse event reporting and creatinine increase (absolute ≥0.3 mg/dL or relative ≥50%), was descriptively reported.

RESULTS

Both dipstick albuminuria and creatinine values were available in 9473 patients (73.2%). More patients with macroalbuminuria, versus no/trace albuminuria, had diabetes (66% vs 27%) or hypertension (86% vs 68%). Rates for CV death and overall mortality per strata were 3.1% and 4.8% (no/trace albuminuria); 5.8% and 9.0% (microalbuminuria); and 7.7% and 12.6% (macroalbuminuria) at 2 years of follow-up. Corresponding rates for CV death or MI were 12.2%, 16.9%, and 23.5%, respectively. Observed acute kidney injury rates were 0.6%, 1.2%, and 2.9% (n = 79), respectively. Adjusted HRs for macroalbuminuria on CV mortality were 1.65 (95% CI 1.15-2.37), and after adjustment with eGFR, 1.37 (95% CI 0.93-2.01). Corresponding HRs for overall mortality were 1.82 (95% CI 1.37-2.42) and 1.47 (95% CI 1.08-1.98).

CONCLUSIONS

High-risk patients with non-ST-segment elevation acute coronary syndromes and albuminuria have increased morbidity and increased overall mortality independent of eGFR.

Effect of age on efficacy and safety of vorapaxar in patients with non-ST-segment elevation acute coronary syndrome: Insights from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial

BACKGROUND

Antithrombotic therapy plays an important role in the treatment of non-ST-segment elevation acute coronary syndromes (NSTE ACS) but is associated with bleeding risk. Advanced age may modify the relationship between efficacy and safety.

METHODS

Efficacy and safety of vorapaxar (a protease-activated receptor 1 antagonist) was analyzed across ages as a continuous and a categorical variable in the 12,944 patients with NSTE ACS enrolled in the TRACER trial. To evaluate the effect of age, Cox regression models were developed to estimate hazard ratios (HRs) with the adjustment of other baseline characteristics and randomized treatment for the primary efficacy composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization, and the primary safety composite of moderate or severe Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) bleeding.

RESULTS

The median age of the population was 64years (25th, 75th percentiles = 58, 71). Also, 1,791 patients (13.8%) were ≤54years of age, 4,968 (38.4%) were between 55 and 64 years, 3,979 (30.7%) were between 65 and 74 years, and 2,206 (17.1%) were 75years or older. Older patients had higher rates of hypertension, renal insufficiency, and previous stroke and worse Killip class. The oldest age group (≥75years) had substantially higher 2-year rates of the composite ischemic end point and moderate or severe GUSTO bleeding compared with the youngest age group (≤54years). The relationships between treatment assignment (vorapaxar vs placebo) and efficacy outcomes did not vary by age. For the primary efficacy end point, the HRs (95% CIs) comparing vorapaxar and placebo in the 4 age groups were as follows: 1.12 (0.88-1.43), 0.88 (0.76-1.02), 0.89 (0.76-1.04), and 0.88 (0.74-1.06), respectively (P value for interaction = .435). Similar to what was observed for efficacy outcomes, we did not observe any interaction between vorapaxar and age on bleeding outcomes. For the composite of moderate or severe bleeding according to the GUSTO classification, the HRs (95% CIs) comparing vorapaxar and placebo in the 4 age groups were 1.73 (0.89-3.34), 1.39 (1.04-1.86), 1.10 (0.85-1.42), and 1.73 (1.29-2.33), respectively (P value for interaction = .574).

CONCLUSION

Older patients had a greater risk for ischemic and bleeding events; however, the efficacy and safety of vorapaxar in NSTE ACS were not significantly influenced by age.

Pooled analysis of adverse event collection from 4 acute coronary syndrome trials

BACKGROUND

Adverse event collection in randomized clinical trials establishes drug safety. Although costly and regulated, it is rarely studied.

METHODS

Adverse event data from 4 clinical trials (APPRAISE-2, PLATO, TRACER, TRILOGY ACS) comprising 48,118 participants with acute coronary syndromes were pooled to compare patterns and determinants of reporting. Events were classified as serious (SAE) or nonserious (AE) from hospital discharge to 1 year; study end points were excluded.

RESULTS

In total, 84,901 events were reported. Of those, 12,266 (14.4%) were SAEs and 72,635 (85.6%) were AEs. Of all participants, 7,823 (16.3%) had SAEs, 18,124 (37.7%) had only AEs, and 22,171 (46.1%) had neither. Nonserious adverse events were distributed across system organ classes: general disorders (11%), infection (10%), gastrointestinal (10%), respiratory (9%), cardiovascular (8.4%), and other (35%). Serious adverse events had a higher proportion of cardiovascular causes (14.0%). Event reporting was highest after hospital discharge, decreasing rapidly during the following 3 months. In a Cox proportional hazards model, chronic obstructive pulmonary disease (hazard ratio 1.58, 95% CI 1.44-1.74), heart failure (1.55, 1.40-1.70), older age, and female sex were independent predictors of more SAEs, whereas enrollment in Eastern Europe (0.63, 0.58-0.69) or Asia (0.84, 0.75-0.94) were independent predictors of fewer SAEs.

CONCLUSIONS

Half of all participants reported adverse events in the year after acute coronary syndrome; most were AEs and occurred within 3 months. The high volume of events, as well as the variation in SAE reporting by characteristics and enrollment region, indicates that efforts to refine event collection in large trials are warranted.

Trends in Enrollment, Clinical Characteristics, Treatment, and Outcomes According to Age in Non-ST-Segment-Elevation Acute Coronary Syndromes Clinical Trials

BACKGROUND

Representation by age ensures appropriate translation of clinical trial results to practice, but, historically, older patients have been underrepresented in clinical trial populations. As the general population has aged, it is unknown whether clinical trial enrollment has changed in parallel.

METHODS AND RESULTS

We studied time trends in enrollment, clinical characteristics, treatment, and outcomes by age among 76 141 patients with non-ST-segment-elevation acute coronary syndrome enrolled in 11 phase III clinical trials over 17 years (1994-2010). Overall, 19.7% of patients were ≥75 years; this proportion increased from 16% during 1994 to 1997 to 21% during 1998 to 2001 and 23.2% during 2002 to 2005, but declined to 20.2% in 2006 to 2010. The number of comorbidities increased with successive time periods irrespective of age. There were substantial increases in the use of evidence-based medication in-hospital and at discharge regardless of age. Although predicted 6-month mortality increased slightly over time, observed 6-month mortality declined significantly in all age strata (1994-1997 versus 2006-2010: <65 years: 3.0% versus 1.9%; 65-74 years: 7.5% versus 3.4%; 75-79 years: 13.0% versus 6.5%; 80-84 years: 17.6% versus 8.2%; and ≥85 years: 24.8% versus 12.6%).

CONCLUSIONS

The distribution of enrollment by age in phase III non-ST-segment-elevation acute coronary syndrome trials was unchanged over time. Irrespective of age, post-myocardial infarction mortality decreased significantly over time, concurrent with increased evidence-based care and despite increasing comorbidities.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00089895.

Use of thienopyridine prior to presentation with non-ST-segment elevation acute coronary syndrome and association with safety and efficacy of vorapaxar: insights from the TRACER trial

BACKGROUND

Vorapaxar is effective in the prevention of secondary atherothrombotic events, although the efficacy/safety balance appears less favorable in the treatment of patients with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS). We hypothesized that patients with NSTE ACS already receiving thienopyridine prior to the ACS event may show differential efficacy/safety effects with vorapaxar vs. placebo added to their standard care.

METHODS

We studied 12,944 patients from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial with respect to thienopyridine use before admission for the index NSTE ACS event. The primary endpoint was a composite of cardiovascular death, myocardial infarction, stroke, rehospitalization for ischemia, and urgent revascularization. The key secondary endpoint was a composite of cardiovascular death, myocardial infarction, and stroke. Safety endpoints were bleeding complications.

RESULTS

Only 1513 patients (11.7%) were receiving thienopyridine before admission for the index NSTE ACS event. In these patients, Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) moderate/severe bleeding occurred in 5.7% treated with vorapaxar and 5.3% treated with a placebo (hazards ratio (HR) 1.10, 95% confidence interval (CI) 0.70-1.71); in thienopyridine-naïve patients, the rates were 5.7% and 4.1%, respectively (HR 1.32, 95% CI 1.11-1.57; P_int=0.45). GUSTO severe bleeding in the prior thienopyridine group occurred in 0.5% of patients treated with vorapaxar and 1.3% of patients treated with placebo (HR 0.34, 95% CI 0.09-1.30); in thienopyridine-naïve patients, the rates were 2.0% and 1.0%, respectively (HR 1.89, 95% CI 1.36-2.62; P_int=0.01). No interaction was observed between vorapaxar efficacy and prior thienopyridine use on the primary (adjusted P_int=0.53) or key secondary endpoints ( P_int=0.61).

CONCLUSIONS

TRACER was largely conducted in thienopyridine-naïve patients with unknown tolerance to multiple antiplatelet treatments. Patients receiving thienopyridine before the index event may have had an attenuated increase in bleeding when adding vorapaxar, whereas concomitantly adding vorapaxar and thienopyridine in naïve patients may have uncovered a latent susceptibility to bleeding.

Efficacy and Safety of Vorapaxar in Non-ST-Segment Elevation Acute Coronary Syndrome Patients Undergoing Noncardiac Surgery

Background

Perioperative antiplatelet agents potentially increase bleeding after non–ST‐segment elevation (NSTE) acute coronary syndromes (ACS). The protease‐activated receptor 1 antagonist vorapaxar reduced cardiovascular events and was associated with increased bleeding versus placebo in NSTE ACS, but its efficacy and safety in noncardiac surgery (NCS) remain unknown. We aimed to evaluate ischemic, bleeding, and long‐term outcomes of vorapaxar in NCS after NSTE ACS.

Methods and Results

In the TRACER trial, 2202 (17.0%) patients underwent major or minor NCS after NSTE ACS over 1.5 years (median); continuing study treatment perioperatively was recommended. The primary ischemic end point for this analysis was cardiovascular death, myocardial infarction, stent thrombosis, or urgent revascularization within 30 days of NCS. Safety outcomes included 30‐day NCS bleeding and GUSTO moderate/severe bleeding. Overall, 1171 vorapaxar and 1031 placebo patients underwent NCS. Preoperative aspirin and thienopyridine use was 96.8% versus 97.7% (P=0.235) and 89.1% versus 86.1% (P=0.036) for vorapaxar versus placebo, respectively. Within 30 days of NCS, no differences were observed in the primary ischemic end point between vorapaxar and placebo groups (3.4% versus 3.9%; adjusted odds ratio 0.81, 95% CI 0.50 to 1.33, P=0.41). Similarly, no differences in NCS bleeding (3.9% versus 3.4%; adjusted odds ratio 1.41, 95% CI 0.87 to 2.31, P=0.17) or GUSTO moderate/severe bleeding (4.2% versus 3.7%; adjusted odds ratio 1.15, 95% CI, 0.72 to 1.83, P=0.55) were observed. In a 30‐day landmarked analysis, NCS patients had a higher long‐term risk of the ischemic end point (adjusted hazard ratio 1.62, 95% CI 1.33 to 1.97, P<0.001) and GUSTO moderate/severe bleeding (adjusted hazard ratio 5.63, 95% CI 3.98 to 7.97, P<0.001) versus patients who did not undergo NCS, independent of study treatment.

Conclusion

NCS after NSTE ACS is common and associated with more ischemic outcomes and bleeding. Vorapaxar after NSTE ACS was not associated with increased perioperative ischemic or bleeding events in patients undergoing NCS.

Infusion of Reconstituted High-Density Lipoprotein, CSL112, in Patients With Atherosclerosis: Safety and Pharmacokinetic Results From a Phase 2a Randomized Clinical Trial

Background

CSL112 is a new formulation of human apolipoprotein A-I (apoA-I) being developed to reduce cardiovascular events following acute coronary syndrome. This phase 2a, randomized, double-blind, multicenter, dose-ranging trial represents the first clinical investigation to assess the safety and pharmacokinetics/pharmacodynamics of a CSL112 infusion among patients with stable atherosclerotic disease.

Methods and Results

Patients were randomized to single ascending doses of CSL112 (1.7, 3.4, or 6.8 g) or placebo, administered over a 2-hour period. Primary safety assessments consisted of alanine aminotransferase or aspartate aminotransferase elevations >3× upper limits of normal and study drug–related adverse events. Pharmacokinetic/pharmacodynamic assessments included apoA-I plasma concentration and measures of the ability of serum to promote cholesterol efflux from cells ex vivo. Of 45 patients randomized, 7, 12, and 14 received 1.7-, 3.4-, and 6.8-g CSL112, respectively, and 11 received placebo. There were no clinically significant elevations (>3× upper limit of normal) in alanine aminotransferase or aspartate aminotransferase. Adverse events were nonserious and mild and occurred in 5 (71%), 5 (41%), and 6 (43%) patients in the CSL112 1.7-, 3.4-, and 6.8-g groups, respectively, compared with 3 (27%) placebo patients. The imbalance in adverse events was attributable to vessel puncture/infusion-site bruising. CSL112 resulted in rapid (T_max≈2 hours) and dose-dependent increases in apoA-I (145% increase in the 6.8-g group) and total cholesterol efflux (up to 3.1-fold higher than placebo) (P<0.001).

Conclusions

CSL112 infusion was well tolerated in patients with stable atherosclerotic disease. CSL112 immediately raised apoA-I levels and caused a rapid and marked increase in the capacity of serum to efflux cholesterol. This potential novel approach for the treatment of atherosclerosis warrants further investigation.

Clinical Trial Registration

URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01499420.

Ticagrelor, prasugrel, or clopidogrel in ST-segment elevation myocardial infarction: which one to choose?

INTRODUCTION

Clopidogrel, prasugrel, and ticagrelor are the currently available oral P2Y12 inhibitors for the treatment of ST-segment elevation myocardial infarction (STEMI), in association with aspirin. These agents bind the P2Y12 platelet receptor and thus inhibit platelet aggregation. Large randomized clinical trials have provided efficacy and safety data on P2Y12 inhibitors in STEMI patients.

AREAS COVERED

This review focuses on key pharmacologic and clinical aspects of clopidogrel, prasugrel, and ticagrelor, highlighting their differences. Results from the main clinical trials are discussed, as well as the current STEMI guideline recommendations, to help inform agent selection for patients presenting with STEMI.

EXPERT OPINION

Clinical trials studying newer P2Y12 inhibitors with increased potency have shown further reduction of cardiovascular events compared with clopidogrel, therefore suggesting the use of ticagrelor or prasugrel as a first-line agent for STEMI treatment. There are still clinical situations - such as fibrinolysis, high risk of bleeding, use of oral anticoagulant, and financial hurdles - in which clopidogrel maintains a role in the treatment of STEMI.

Sex-Stratified Trends in Enrollment, Patient Characteristics, Treatment, and Outcomes Among Non-ST-Segment Elevation Acute Coronary Syndrome Patients: Insights From Clinical Trials Over 17 Years

BACKGROUND

Adequate representation by sex in trials allows generalizability of results. We examined representation of women in clinical trials during a 17-year period in which inclusion criteria were broadened and federal mandates for representativeness were launched.

METHODS AND RESULTS

Using mixed models, we studied sex-stratified temporal trends in enrollment, clinical characteristics, treatment, and outcomes among 76 148 non-ST-segment elevation acute coronary syndrome patients using patient-level data merged from 11 phase III trials conducted from 1994 to 2010. Overall, 33.3% of patients were women, which changed minimally over time. Women were consistently 4 to 5 years older than men (median age 68 [interquartile range 61-75] versus 64 [interquartile range 56-72] years) and more frequently had diabetes mellitus, hypertension, and heart failure; men more frequently had prior myocardial infarction and revascularization. GRACE risk scores increased over time for both sexes with the inclusion of older patients with more comorbidities. Use of percutaneous coronary intervention, in-hospital and discharge angiotensin-converting enzyme inhibitor/angiotensin II receptor blockers, β-blockers, and lipid-lowering drugs also increased among both sexes. Kaplan-Meier estimates of 6-month mortality declined from 7.0% [95% confidence interval 6.5%-7.6%] to 4.5% [95% confidence interval 4.0%-5.0%] among women and 6.3% [95% confidence interval 6.0%-6.7%] to 3.1% [95% confidence interval 2.9%-3.4%] among men during the 17-year period.

CONCLUSIONS

The relative proportion of women in non-ST-segment elevation acute coronary syndrome trials changed minimally over time. Nevertheless, in parallel with men, use of evidence-based care and outcomes improved significantly over time among women.

Meta-analysis of intracranial hemorrhage in acute coronary syndromes: incidence, predictors, and clinical outcomes

BACKGROUND

Little is known about the incidence, predictors, or outcomes of intracranial hemorrhage (ICH) in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). We aimed to determine the incidence and timing of ICH, characterize the location of ICH, and identify independent baseline predictors of ICH in NSTE ACS patients.

METHODS AND RESULTS

We pooled patient-level data from 4 contemporary antithrombotic therapy trials. Multivariable modeling identified independent predictors of ICH. ICHs were adjudicated by a clinical events committee. Of 37 815 patients, 135 (0.4%) had an ICH. The median (25th, 75th percentiles) follow-up was 332 (184, 434) days but differed across trials. Locations of ICH were intracerebral (50%), subdural (31%), subarachnoid (18.5%), and intraventricular (11%). Independent predictors of ICH were older age (HR per 10 years, 1.61; 95% CI, 1.35 to 1.91); prior stroke/transient ischemic attack; HR, 1.95; 95% CI, 1.14 to 3.35), higher systolic blood pressure; HR per 10 mm Hg increase, 1.09; 95% CI, 1.01 to 1.18), and larger number of antithrombotic agents (HR per each additional agent, 2.06; 95% CI, 1.49 to 2.84). Of all ICHs, 45 (33%) were fatal.

CONCLUSIONS

In patients with NSTE ACS enrolled in recent clinical trials of antithrombotic therapies, ICH was uncommon. Patients with older age, prior transient ischemic attack/stroke, higher systolic blood pressure, or larger number of antithrombotic agents were at increased risk. One-third of patients with ICH died. These data may be useful to trialists and data and safety monitoring committees for trial conduct and monitoring.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifiers: TRACER: NCT00527943, PLATO: NCT00391872, APPRAISE-2: NCT00831441, TRILOGY ACS: NCT00699998.

Magnitude of Troponin Elevation and Long-Term Clinical Outcomes in Acute Coronary Syndrome Patients Treated With and Without Revascularization

Background—

In patients with non–ST-segment–elevation acute coronary syndrome (NSTE ACS), elevated troponin levels identify patients at high risk for adverse outcomes; however, it is unknown whether the magnitude of troponin elevation during hospitalization remains predictive of subsequent events in patients undergoing coronary revascularization.

Methods and Results—

We studied 12 635 patients with NSTE ACS in the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) study with at least 1 troponin measurement during index hospitalization. Cox proportional hazards regression was used to examine the relationship between peak troponin level (standardized as the ratio of peak troponin value measured during hospitalization and local laboratory upper reference limit [URL]) and revascularization on all-cause mortality at 2 years. Revascularization (percutaneous coronary intervention or coronary artery bypass graft) was performed during index hospitalization in 8586 patients (68.0%); revascularized patients had higher peak troponin ratios (median, 23 versus 9.5× URL). Among patients that did not undergo revascularization, the mortality rate at 2 years increased in a curvilinear fashion with increasing levels of peak troponin. In contrast, the mortality rate at 2 years remained constant irrespective of peak troponin levels among revascularized patients ( P for interaction=0.004). This relationship was unchanged after multivariable adjustment.

Conclusions—

There is a differential relationship between the magnitude of troponin elevation and long-term mortality in ACS patients treated with and without revascularization. Although prognostically important in patients treated without revascularization, the prognostic implications of peak troponin level seem to be minimal in revascularized patients.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00527943.

Glycoprotein IIb/IIIa Receptor Inhibitors in Combination With Vorapaxar, a Platelet Thrombin Receptor Antagonist, Among Patients With Non-ST-Segment Elevation Acute Coronary Syndromes (from the TRACER Trial)

We evaluated the interaction between protease-activated receptor-1 antagonist vorapaxar and concomitant glycoprotein (GP) IIb/IIIa receptor inhibitors in patients with non-ST-segment elevation acute coronary syndromes who underwent PCI. In Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome trial, 12,944 patients with non-ST-segment elevation acute coronary syndromes were randomized to vorapaxar or placebo. Administration of GP IIb/IIIa receptor inhibitors was allowed at the treating physician's discretion. We investigated whether use of GP IIb/IIIa receptor inhibitors modified vorapaxar's effect on non-coronary artery bypass grafting (CABG)-related bleeding at 7 days and ischemic events at 30 days. In total, 7,455 patients underwent PCI during index hospitalization. Of these, 2,023 patients (27.1%) received inhibitors and 5,432 (72.9%) did not. Vorapaxar was associated with a numerically higher rate of non-CABG-related moderate/severe Global Use of Strategies to Open Occluded Arteries (GUSTO) bleeding at 7 days compared with placebo in those who did (1.3% vs 1.0%) and did not (0.6% vs 0.4%) receive GP IIb/IIIa receptor inhibitors. Ischemic end point rates at 30 days were not significantly lower with vorapaxar versus placebo. Increased rates of non-CABG GUSTO moderate/severe bleeding were observed in patients who received GP IIb/IIIa receptor inhibitors versus those who did not (adjusted hazard ratio [HR] 1.77, 95% confidence interval [CI] 0.43 to 7.35 in placebo arm; adjusted HR 2.02, 95% CI 0.62 to 6.61 in vorapaxar arm) and in those who received vorapaxar versus placebo (adjusted HR 1.54, 95% CI 0.36 to 6.56 in the GP IIb/IIIa group; adjusted HR 1.34, 95% CI 0.44 to 4.07 in the no-GP IIb/IIIa group). No interaction was found between vorapaxar and inhibitor use up to 7 days (P interaction = 0.89) nor at the end of the treatment (P interaction = 0.74); however, the event rate was low. Also, no interaction was observed for efficacy end points after PCI at 30 days or at the end of the treatment. In conclusion, GP IIb/IIIa receptor inhibitor use plus dual antiplatelet therapy in a population with non-ST-segment elevation myocardial infarction planned for PCI was frequent but did not interact with vorapaxar's efficacy or safety. Nonetheless, GP IIb/IIIa receptor inhibitors and vorapaxar were associated with increased bleeding risk, and their combined use may result in additive effects on bleeding rates.

Long-term outcomes and causes of death after acute coronary syndrome in patients in the Bologna, Italy, area

We sought to evaluate the rates, time course, and causes of death in the long-term follow-up of unselected patients with acute coronary syndromes (ACS). We enrolled 2046 consecutive patients hospitalized from January 2004 to December 2005 with an audited final diagnosis of ACS. The primary study end point was 5-year all-cause mortality. In our series, 896 patients had ST-segment elevation (STE) and 1,150 non-ST-segment elevation (NSTE). Mean age of the study population was 71.6 years. Primary percutaneous coronary intervention was performed in 86% of STE-ACS, and 70% of NSTE-ACS was managed invasively. The 5-year all-cause mortality was 36.4% for STE-ACS and 42.0% for NSTE-ACS, with patients with STE-ACS showing a trend boarding statistical significance toward a lower risk of mortality (hazard ratio [HR] = 0.88, 95% confidence interval [CI] 0.76 to 1.02, p = 0.08). Landmark analysis demonstrated that patients with STE-ACS had a higher risk of 30-day mortality (STE-ACS vs NSTE-ACS HR = 1.53, 95% CI 1.16 to 2.06, p = 0.003) whereas the risk of NSTE-ACS increased markedly after 1 year (STE-ACS vs NSTE-ACS HR = 0.67, 95% CI 0.53 to 0.84, p = 0.001). The contribution of noncardiovascular (CV) causes to overall mortality increased from 3% at 30 days to 34% at 5 years, with cancer and infections being the most common causes of non-CV death both in STE-ACS and NSTE-ACS. In conclusion, long-term mortality after ACS is still too high both for STE-ACS and NSTE-ACS. Although patients with STE-ACS have a higher mortality during the first year, the mortality of patients with NSTE-ACS increases later, when non-CV co-morbidities gain greater importance.