The role of stress cardiovascular magnetic resonance in patients with Diabetes Mellitus (RF_SA_456)

Background: Diabetic individuals are at increased risk of coronary atherosclerosis. A significant percentage of diabetics fail to perceive the typical symptoms of myocardial ischemia. Screening methods such as coronary computed tomography (CCTA) or single-photon emission computed tomography (SPECT) have not shown clear benefits in asymptomatic diabetics. The role of stress CMR in this population remains uncertain. 

The aim of this study was to evaluate the prognostic value of stress perfusion cardiovascular magnetic resonance (CMR) in diabetic versus non-diabetic patients and in symptomatic versus asymptomatic diabetics.  

Methods: Between 2008 and 2018, consecutive diabetic and non-diabetic patients without known cardiovascular disease, history of heart failure or atrial fibrillation, referred for stress perfusion CMR were included. Propensity-score matching was used to create a cohort of patients with similar baseline characteristics. All patients were followed for the occurrence of major adverse cardiovascular events (MACE), defined as cardiovascular death or nonfatal myocardial infarction. Diabetic patients were categorized into symptomatic and asymptomatic subgroups. 

Results: Out of 3,485 eligible patients, 1,359 diabetics and 1,359 non-diabetics (mean age 69±12 years, 57.4% women) with similar propensity scores were included. Over a median follow-up period of 6.5 (5.9-8.9) years, 386 (14.2%) experienced MACEs. Kaplan-Meier analysis for the occurrence of MACE indicated that the extent of ischemia or late gadolinium enhancement (LGE) involving ≥ 3 segments were independent predictors of the occurrence of MACEs (hazard ratio, HR: 7.14 [95% CI, 5.01–10.02]; and HR: 5.03 [95% CI, 3.47–7.29]; both p< 0.001, respectively), with no significant differences between diabetics and non-diabetics. Asymptomatic diabetics (n=255) showed similar event rates as symptomatic patients (p=0.98). Patients with a left ventricular ejection fraction (LVEF) between 40-50% had worse outcomes than those with an LVEF < 40%.  

Conclusion: Stress CMR provides valuable prognostic information in diabetic patients, irrespective of symptoms. Further assessment is needed to determine whether stress CMR should be a standard screening tool for diabetic patients.