Abnormal myocardial perfusion reserve and myocardial infarction determine cardiovascular outcomes in type 2 diabetes mellitus

AIMS: In individuals with type 2 diabetes mellitus (T2DM), both myocardial ischemia and myocardial infarction (MI) are associated with adverse cardiovascular outcomes. The incremental prognosis of both risks is unknown. We aimed to investigate whether abnormal myocardial perfusion reserve (MPR), as a surrogate marker for ischemia and presence of MI offers incremental prognostic value in predicting major adverse cardiovascular and cerebrovascular events (MACCE) in patients with T2DM. METHODS AND RESULTS: A retrospective multicentre cohort of 572 individuals with T2DM and healthy controls underwent quantitative stress myocardial perfusion cardiovascular magnetic resonance (CMR) to determine MPR and late gadolinium enhancement (LGE) to identify MI. Patients were divided into three groups: MI- and normal MPR, MI+ or abnormal MPR and MI+ and abnormal MPR. Cox proportional hazard models quantified associations between MPR and MI with MACCE (composite of all-cause death, MI, stroke, heart failure hospitalization, and late coronary revascularization>90 days after the CMR scan). Over a median of 28 months (IQR 25-31 months), 81 participants (14%) accrued at least one MACCE, including 25 (4%) deaths. Presence of either abnormal MPR or MI was associated with increased MACCE (MI- and normal MPR: 8% MACCE; MI+ or abnormal MPR: 15% MACCE (adjusted HR compared with normal 1.86 (95% CI 1.06-3.25, P = 0.03)); presence of both MI and abnormal MPR had the highest event rate: 30% MACCE (adjusted HR compared with normal 3.24 (95% CI 1.75-6.01, P < 0.001)). CONCLUSION: In T2DM, abnormal MPR or MI are associated with MACCE, and the presence of both offers incremental prognostic value.