Impact of left ventricular function and the extent of ischemia and scar by stress myocardial perfusion imaging on prognosis and therapeutic risk reduction in diabetic patients with coronary artery disease: Results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial
Journal of Nuclear Cardiology, 05/17/2012
Shaw LJ et al. – Patient management strategies that focus on ischemia resolution can be useful to guide the efficacy of near–term therapeutic approaches. A 1–year post–therapeutic intervention myocardial perfusion scan provides important information regarding prognosis in stable CAD patients with diabetes.Methods
- MPS was performed in 1,505 patients at 1–year following randomization.
- MPS images were analyzed (masked to treatment) by a Nuclear Core Laboratory using a quantitative percent (%) of total, ischemic, and scarred myocardium.
- Cox proportional hazards models were used to estimate the relationship between MPS variables and trial endpoints.
- At 1–year, nearly all REV patients underwent the assigned procedure; while 16% of those randomized to MED received coronary REV.
- Patients randomized to REV exhibited fewer stress perfusion abnormalities than MED patients (P < .001).
- CABG patients had more frequent ischemic and scarred myocardium encumbering ≥5% of the myocardium when compared to those receiving PCI.
- Patients randomized to MED had more extensive ischemia and the median % of the myocardium with perfusion abnormalities was lower following REV (3% vs 9%, P = .01).
- A total of 59% of REV patients had no inducible ischemia at 1–year compared to 49% of MED patients (P < .001).
- Within the CABG stratum, those randomized to MED had the greatest rate of ischemic (P = .032) and scarred (P = .017) perfusion abnormalities.
- At 1–year, more extensive and severe stress myocardial perfusion abnormalities were associated with higher 5–year rates of death and a combined endpoint of cardiac death or myocardial infarction (MI) rates (11.3%, 8.1%, 6.8%, for ≥10%, 5%–9.9%, and 1–4.9% abnormal myocardium at stress, respectively, P < .001).
- In adjusted models, selected MPS variables were significantly associated with an increased hazard of cardiac death or MI (hazard ratio = 1.11 per 5% increase in abnormal myocardium at stress, P = .004).