Changes in coronary plaque morphology in patients with acute coronary syndrome versus stable angina pectoris after initiation of statin therapy.

OBJECTIVES: The aim of this study was to examine coronary plaque morphology after initiation of statins and compare changes in plaque morphology in patients presenting with acute coronary syndrome (ACS) versus stable angina pectoris (SAP).

BACKGROUND: ACS is associated with a pan-inflammatory state, and intraplaque features of inflammation correlate with coronary plaque progression. Statins have known anti-inflammatory properties that may contribute toward their beneficial cardiovascular effects.

METHODS: Sixty-nine statin-naive patients (ACS, n=55; SAP, n=14) underwent baseline imaging with optical coherence tomography and intravascular ultrasound. Repeat imaging was performed at 6 and 12 months. A total of 97 nonculprit plaques were analyzed (ACS, n=74; SAP, n=23).

RESULTS: Fibrous cap thickness increased in both ACS and SAP patients (all P<0.001 compared with the baseline); the ACS group showed greater percent change in fibrous cap thickness at 12 months (192.8±148.9% in ACS vs. 128.2±88.7% in SAP, P=0.018). The ACS group also showed a significant decrease in plaque microvessels (44.6% at baseline vs. 26.6% at 12 months, P=0.0386).

CONCLUSION: Compared with patients with SAP, patients presenting with ACS show more favorable changes in plaque morphology after starting statin treatment. This supports a potential additive benefit of statins in the inflammatory state of ACS and reaffirms the clinical importance of statin therapy for coronary atherosclerosis.