Antiplatelet therapy in patients with myocardial infarction without obstructive coronary artery disease

Matthias Bossard, Peggy Gao, William Boden, Gabriel Steg, Jean-Francois Tanguay, Cam Joyner, Christopher B. Granger, Adnan Kastrati, David Faxon, Andrzej Budaj, Prem Pais, Giuseppe Di Pasquale, Vicent Valentin, Marcus Flather, Tiziano Moccetti, Salim Yusuf, Shamir R. Mehta

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21 Citations (Scopus)

Abstract

Objective: Approximately 10% of patients with myocardial infarction (MI) have no obstructive coronary artery disease. The prognosis and role of intensified antiplatelet therapy in those patients were evaluated. Methods: We analysed data from the Clopidogrel and Aspirin Optimal Dose Usage to Reduce Recurrent Events-Seventh Organisation to Assess Strategies in Ischaemic Symptoms trial randomising patients with ACS referred for early intervention to receive either double-dose (600 mg, day 1; 150 mg, days 2-7; then 75 mg/day) or standard-dose (300 mg, day 1; then 75 mg/day) clopidogrel. Outcomes in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) versus those with obstructive coronary artery disease (CAD) and their relation to standard-dose versus double-dose clopidogrel were evaluated. The primary outcome was cardiovascular (CV) death, MI or stroke at 30 days. Results: We included 23 783 patients with MI and 1599 (6.7%) with MINOCA. Patients with MINOCA were younger, presented more frequently with non-ST-segment elevation MI and had fewer comorbidities. All-cause mortality (0.6% vs 2.3%, p=0.005), CV mortality (0.6% vs 2.2%, p=0.006), repeat MI (0.5% vs 2.3%, p=0.001) and major bleeding (0.6% vs 2.4%, p<0.0001) were lower among patients with MINOCA than among those with obstructive CAD. Among patients with MINOCA, 2.1% of patients in the double-dose clopidogrel group and 0.6% in the standard-dose group experienced a primary outcome (HR 3.57, 95% CI 1.31 to 9.76), whereas in those with obstructive CAD, rates were 4.3% and 4.7%, respectively (HR 0.91, 95% CI 0.80 to 1.03; p value for interaction=0.011). Conclusions: Patients with MINOCA are at lower risk of recurrent CV events compared with patients with MI with obstructive CAD. Compared with a standard clopidogrel-based dual antiplatelet therapy (DAPT) regimen, an intensified dosing strategy appears to offer no additional benefit with a signal of possible harm. Further randomised trials evaluating the effects of potent DAPT in patients with MINOCA are warranted. Trial registration number: NCT00335452.

Original languageEnglish
Pages (from-to)1739-1747
Number of pages9
JournalHeart
Volume107
Issue number21
Early online date27 Jan 2021
DOIs
Publication statusPublished - 1 Nov 2021

Keywords

  • acute coronary syndromes
  • acute myocardial infarction
  • coronary artery disease

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