Rationale and design of switch Swedeheart: A registry-based, stepped-wedge, cluster-randomized, open-label multicenter trial to compare prasugrel and ticagrelor for treatment of patients with acute coronary syndrome.

Background: European treatment guidelines recommend prasugrel over ticagrelor for treating patients with non-ST-elevation acute coronary syndrome (ACS), prompting several Swedish administrative regions to transition from ticagrelor to prasugrel as the preferred treatment for patients with ACS. We aim to systematically evaluate this transition to determine the relative efficacy of prasugrel versus ticagrelor in a real-world cohort of patients with ACS.

Study Design And Objectives: The SWITCH SWEDEHEART trial is a prospective, multicenter, open-label, cross-sectional, stepped-wedge cluster-randomized clinical trial, in which administrative regions in Sweden will constitute the clusters. At the start of the study, all clusters will use ticagrelor as the P2Y12 inhibitor drug of choice for ACS. The order in which the clusters will implement the transition from ticagrelor to prasugrel will be randomly assigned. Every 9 months, 1 cluster will switch from ticagrelor to prasugrel as the P2Y12 inhibitor of choice for patients with ACS. The primary endpoint is the composite 1-year rate of the death, stroke, or myocardial infarction.

Conclusions: The SWITCH SWEDEHEART study will provide an extensive randomized comparison between ticagrelor and prasugrel. Novel therapies are frequently costly and supported by evidence from few or small studies, and systematic evaluation after the introduction is rare. This study will establish an important standard for introducing and evaluating the effects of health care changes within our societies.