Quantitiative CMR may independently predict adverse outcome
A retrospective analysis of consecutive patients with prior CABG referred for adenosine stress perfusion cardiac magnetic resonance (CMR). Perfusion mapping was performed in-line with automated quantification of myocardial blood flow (MBF). The primary outcome was a composite of all-cause mortality and major adverse cardiovascular events defined as nonfatal myocardial infarction and unplanned revascularization.

A total of 341 patients (median age 67 years, 86% male) were included. Over a median follow-up of 638 days (IQR: 367-976 days), 81 patients (24%) reached the primary outcome. Both stress MBF and myocardial perfusion reserve (MPR) independently predicted outcomes after adjusting for known prognostic factors (regional ischemia, infarction). The adjusted hazard ratio (HR) for 1 mL/g/min of decrease in stress MBF was 2.56 (95% CI: 1.45-4.35) and for 1 unit of decrease in MPR was 1.61 (95% CI: 1.08-2.38).

Global stress MBF and MPR derived from perfusion CMR independently predict adverse outcomes in patients with previous CABG. This effect is independent from the presence of regional ischemia on visual assessment and the extent of previous infarction.

Source: https://www.jacc.org/doi/10.1016/j.jacc.2021.12.037