Relation of Plaque Size to Necrotic Core in the Three Major Coronary Arteries in Patients With Acute Coronary Syndrome as Determined by Intravascular Ultrasonic Imaging Radiofrequency

According to pathologic studies, the content of a necrotic core increases in a “linear fashion” as plaque enlarges. In addition, these 2 plaque characteristics have been associated with plaque vulnerability. This study assessed the relation between plaque cross-sectional area (CSA) and content of necrotic core (NC). Twenty-five patients (75 arteries) with acute coronary syndrome were studied. In total, 7,834 CSAs were analyzed. An analysis of plaque CSA in percentiles was performed (median 5.5 mm², interquartile range 3.7 to 7.8); subsequently, plaque CSA values were categorized as small (≤3.7 mm²), medium (>3.7 to ≤7.8 mm²), and large (>7.8 mm²). There was a difference in content of the NC between arteries within each plaque CSA category. This observation was confirmed in a multivariate analysis in which only 2 variables remained statistically significant, plaque CSA (estimate 1.34, SE 0.05, p <0.0001) and studied artery (left anterior descending coronary artery, estimate 0.29, SE 0.08, p = 0.0003; left circumflex coronary artery, estimate 0.23, SE 0.07, p = 0.0014; and these vs the right coronary artery). In conclusion, the NC and plaque increase in patients with acute coronary syndromes.