Incident Myocardial Infarction and Very Late Stent Thrombosis in Outpatients With Stable Coronary Artery Disease

Background: Current data are lacking for incidence, correlates, and prognosis associated with incident myocardial infarction (MI) in patients with stable coronary artery disease (CAD). Furthermore, the contribution of very late stent thrombosis (VLST) to these events remains poorly understood.

Objectives: This study aimed to analyze the residual risk of MI, together with relevant associated factors, and related mortality in stable CAD outpatients.

Methods: The multicenter CORONOR (Suivi d'une cohorte de patients COROnariens stables en region NORd-Pas-de-Calais) study enrolled 4,184 unselected outpatients with stable CAD (i.e., MI or coronary revascularization >1 year previously). Five-year follow-up was achieved for 4,094 patients (98%).

Results: We identified a linear risk of incident MI (0.8% annually), with ST-segment elevation MI constituting one-third of all cases. Current smoking, low-density lipoprotein cholesterol, multivessel CAD, diabetes with glycosylated hemoglobin >7%, and persistent angina were all associated with increased risk, and prior bypass surgery was associated with decreased risk. When used as a time-dependent variable, incident MI was associated with an increased risk of death (hazard ratio: 2.05; p < 0.0001). Among patients with prior stent implantation, VLST was causal in 20% of MI cases and presented more often as ST-segment elevation MI versus MI not related to a stented site (59% vs. 26%, p = 0.001). Adjusted mortality was 4 times higher in patients with VLST than in MI not related to a stented site.

Conclusions: In stable CAD outpatients, incident MI occurs at a stable rate of 0.8% annually, is related to VLST in one-fifth of cases, and is associated with an increased mortality risk, especially for VLST. Multivessel CAD and residual uncontrolled risk factors are strongly associated with MI.