Long-term prognosis of patients with non-ST-segment elevation myocardial infarction according to coronary arteries atherosclerosis extent on coronary angiography: a historical cohort study.

Background: Patients with non-ST-segment elevation myocardial infarction (NSTEMI) without obstructive coronary artery disease (CAD) are often managed differently than those with obstructive CAD, therefore we aimed in this study to examine the long-term prognosis of patients with NSTEMI according to the degree of CAD on coronary angiography (CAG).

Methods: We examined 8.889 consecutive patients admitted for first time NSTEMI during 2000-2011, to whom CAG was performed. Patients were classified by CAG into: 0-vessel disease (0VD), diffuse atherosclerosis (DA) (0% < stenosis <50%), 1-vessel disease (1VD), 2VD, and 3VD with stenosis ≥50%. Follow-up period: 13 years (median 4.5).

Results: One-year mortality for NSTEMI patients with 0VD was 3.7%, DA 5.7%, 1VD 2.5%, 2VD 4.8%, and 3VD 11.5%. Non-diabetic 0VD patients had higher risk of mortality than 1VD patients (HR:1.59; 95% CI:1.21-2.02; P < 0.001), while those with diabetes mellitus (DM) had not significantly different risk. In addition 0VD group had higher risk of heart failure (HF) (HR 1.61; 95% CI: 1.39-1.88; P < 0.001), and lower risk of recurrent MI (HR:0.55; 95% CI:0.39-0.77; P < 0.001) compared with 1VD. For patients with DA; mortality and HF risks were higher than 1VD and not different than 2VD, while recurrent MI risk was not different than 1VD and lower than 2VD. Finally, the DA group had higher risk of mortality if they had DM, higher risk of recurrent MI, and not different risk of HF and stroke compared with the 0VD group patients.

Conclusion: Patients with NSTEMI and non-obstructive CAD (both normal coronaries and diffuse atherosclerosis) have a comparable prognosis to patients with one- or two-vessel disease. Patients with diffuse atherosclerosis have worse prognosis than those with angiographically normal coronary arteries.