Treatment With ADP Receptor Inhibitors: Longitudinal Assessment of Treatment Patterns and Events After Acute Coronary Syndrome Prospective Open-Label Antiplatelet Study - TRANSLATE-POPS

Description:

Current guidelines list platelet testing as a Class IIb indication in select patients with unstable angina/non–ST-segment elevation myocardial infarction (NSTEMI) if testing would change clinical management. To date, however, randomized clinical trials have failed to demonstrate that altering adenosine diphosphate (ADP) therapy in response to platelet function testing improves patient outcomes.

The current trial sought to study if access to platelet testing in routine clinical practice would change clinical practice of prescribing physicians, and if this was associated with improved patient outcomes.

Hypothesis:

Among hospitals treating STEMI and NSTEMI patients with percutaneous coronary intervention (PCI), access to no-cost platelet function testing would increase therapeutic adjustments of ADP receptor inhibitor treatment prior to discharge, and improve patient outcomes.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • STEMI and NSTEMI patients treated with PCI and an ADP receptor inhibitor
  • All TRANSLATE-ACS hospitals who did not routinely (<30%) perform platelet function testing

    Number of enrollees: 3,866
    Duration of follow-up: 1 month
    Mean patient age: 60 years
    Percentage female: 27%

Exclusions:

  • Unable to provide written consent for follow-up
  • Participating in a randomized clinical trial that specified ADP receptor inhibitor use in the first year after acute MI

Primary Endpoints:

  • Incidence of ADP receptor inhibitor therapy adjustment before hospital discharge, including:
    - Change in dose of ADP receptor inhibitor
    - Switching of ADP receptor inhibitor

Secondary Endpoints:

  • Thirty-day MACE: composite of all-cause death, recurrent MI, stroke, or unplanned coronary revascularization
  • Thirty-day bleeding: using GUSTO criteria

Drug/Procedures Used:

In a cluster randomization, patients were randomized to the device arm or usual care arm. In the device arm, sites were provided with no-cost VerifyNow P2Y12 test. Testing was to be performed prior to discharge and at least 12 hours after PCI. Test results were available to the care team; response was up to the team caring for the patient. In the usual care arm, sites were not provided with routine platelet testing. This could be performed if deemed clinically necessary.

Principal Findings:

A total of 100 sites (3,866 patients) were randomized, 50 (2,013 patients) to the device arm and 50 (1,853 patients) to usual care. Baseline characteristics were fairly similar between the two arms. Approximately 22% had undergone prior PCI and 9% prior coronary artery bypass grafting (CABG); history of stroke was present in 5% of patients. Nearly 51% of patients presented with STEMI and underwent PCI. Clopidogrel was the initial thienopyridine of choice (74%), with prasugrel being used in the rest. A loading dose of either drug was given in >90% of patients.

In the device arm, 66.4% of patients underwent platelet testing compared with 1.4% in the usual care arm. High platelet reactivity (PRU ≥208 or 235) was observed in nearly 30% of patients in both arms. The primary endpoint of the study, therapeutic adjustment in antiplatelet therapy, was significantly higher in the device arm as compared with the usual care arm (15.9% vs. 11.6%, p = 0.01). In the device arm, therapeutic adjustments occurred in 31% patients with PRU ≥235 and in 29% patients with PRU ≥208. The majority of the adjustments were in change of antiplatelet medication (clopidogrel to prasugrel or ticagrelor) (14.7% vs. 9.7%, p = 0.004).

The incidence of major adverse cardiac events (MACE) at 30 days was similar between the two arms (4.5% vs. 5.1%, odds ratio 0.93, 95% confidence interval 0.66-1.31, p = 0.69). GUSTO bleeding at 30 days was also similar (4.2% vs. 4.3%, p = 0.33).

Interpretation:

The results of the TRANSLATE-POPS trial indicate that access to platelet testing has a modest response on tailoring of antiplatelet therapy. Increased access (and increased testing) is not associated with an improvement in short-term outcomes. The latter finding is consistent with data from randomized clinical trials showing no benefit with routine testing in patients undergoing PCI for acute coronary syndrome.

The current trial had an interesting study design in that it was designed to reflect “real-world” practice. No protocols were established for testing or for making changes to antiplatelet therapy.

References:

Presented by Dr. Tracy Wang at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2013), San Francisco, CA, October 31, 2013.

Clinical Topics: Acute Coronary Syndromes, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery, Interventions and ACS

Keywords: Odds Ratio, Myocardial Infarction, Stroke, Acute Coronary Syndrome, Follow-Up Studies, Platelet Function Tests, Receptors, Purinergic P2, Ticlopidine, Blood Platelets, Piperazines, Percutaneous Coronary Intervention, Confidence Intervals, Coronary Artery Bypass


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