Q. A 67-year-old woman comes to the emergency department because of severe epigastric pain. Shortly after arrival, the patient becomes unresponsive and subsequently dies after extensive resuscitation efforts. Her autopsy reveals a dilatation of the abdominal aorta with focal rupture at its upper pole. The left anterior descending coronary artery shows multiple yellowish streaks consistent with atheromatous plaques. Regarding the coronary findings, which of the following factors decreases the stability of plaques?