The importance of malapposition in angiographically optimized stenting in contemporaneous interventions

Stenting has advanced the treatment of coronary artery disease, with angiography being historically the gold standard to assure adequate stent deployment. However, intravascular imaging modalities including intravascular ultrasound and optical coherence tomography have shown high rates of inadequate stent deployment in angiographically optimized stents. The association of malapposition with adverse clinical outcomes remains controversial. Areas covered: The definition, types, and risk factors for metallic stent malapposition, the natural history, and significance of stent strut malapposition and its correlation with short- and long-term outcomes were reviewed. Expert commentary: Using intravascular imaging, acute stent strut malapposition is very common, occurring in >75% in some studies. Malapposition may be a result of inadequate stent deployment technique or the atherosclerotic process itself. The preponderance of available data suggests that acute malapposition is not associated with worsened outcomes. Late acquired malapposition may be associated with a relatively increased event rate for stent thrombosis and myocardial infarction but the increased risk is quite small (<0.01%) in absolute terms. Use of a classification system based on cause rather than simple presence of malapposition may clarify some of the uncertainties regarding the clinical significance of strut malapposition.