βeta blocker interruption after uncomplicated myocardial infarction: rationale and design of the randomized ABYSS trial

The long-term use of β-blocker after myocardial infarction (MI) when global left ventricular ejection fraction (LVEF) is preserved has not been studied in the era of modern myocardial reperfusion and secondary prevention therapies. It is unknown whether β-blockers are useful in stable post-MI patients without reduced LVEF and without heart failure.The Assessment of β-blocker interruption 1 Year after an uncomplicated myocardial infarction on Safety and Symptomatic cardiac events requiring hospitalization (ABYSS) Trial enrolled in 49 centers in France, 3,700 patients with a prior (>6 months) history of MI and a LVEF >40%, chronically treated with a β-blocker and without any major cardiovascular event (MACE) in the past 6 months. These patients were randomized to interruption or continuation of their β-blocker therapy. The primary objective is to demonstrate the noninferiority of interruption vs continuation of the β-blocker therapy on the primary composite endpoint of all-cause death, stroke, MI, hospitalization for any cardiovascular reason at the end of follow-up (accrual follow-up) with a one-year minimum follow-up for the last randomized patient. Secondary objectives will focus on patient reported outcomes with the evaluation of the quality of life before and after randomization with the EQ5D-5L questionnaire. Enrolment has been completed.The ABYSS trial evaluates the cardiovascular safety of β-blocker interruption in stabilized post-MI patients without heart failure nor reduced LVEF. ABYSS trial is a reappraisal of β-blockers life-long therapy in stable post-MI patients without reduced LVEF.NCT03498066 (clinicaltrials.gov).