Rationale and design of the MAPS trial: A nationwide multicenter prospective validation of CT-derived index of microcirculatory resistance for precision ischemia management.

BACKGROUND

Coronary microvascular dysfunction (CMD) is a common, underdiagnosed cause of ischemia linked to adverse cardiovascular outcomes. However, the lack of a direct, readily accessible non-invasive diagnostic tool hampers its timely identification and management. We developed IMRCT-a non-invasive, CT-derived index of microcirculatory resistance based on computational fluid dynamics (CFD)-enabling comprehensive hemodynamic phenotyping from a single coronary CT angiography (CCTA) examination.

OBJECTIVES

The MAPS trial is a nationwide, multicenter, prospective study. The primary objective is to evaluate the sensitivity and specificity of IMRCT for identifying CMD, using invasively measured index of microcirculatory resistance (IMR) as the reference standard. Secondary objectives include assessing the prognostic value of IMRCT for major adverse cardiovascular events (MACE). Exploratory analyses will assess the agreement of CT-derived coronary flow reserve (CFRCT) and microvascular resistance reserve (MRRCT) with their invasive counterparts.

METHODS

A total of 630 patients referred for clinically indicated invasive coronary physiology assessment will be enrolled. All patients will undergo CCTA followed by invasive measurements of IMR and CFR, and relevant pressure/flow parameters. Patient-specific 3D models and CFD simulations will be used to compute IMRCT, CFRCT and MRRCT. All participants will be followed every six months for ≥2 years to assess MACE and symptom progression.

SUMMARY: The MAPS trial is designed to establish IMRCT as a non-invasive window into coronary microvascular physiology and a potential tool for physiology-guided therapy and longitudinal monitoring through repeat CCTA.