Abstract 4149: Regression of Coronary Atherosclerosis Following Intensive Risk Factor Modification in Patients With the Metabolic Syndrome
Background: Metabolic syndrome (MS) is associated with an increased incidence of coronary artery disease (CAD). The factors that result in clinical events in patients with MS remain to be elucidated. This study characterized the extent of atherosclerosis, pattern of arterial remodeling and rate of plaque progression with medical therapy in patients with MS.
Methods: Serial intravascular ultrasound analysis of matched coronary artery segments was performed in 1327 patients with angiographically documented CAD. Patients with (n=675) and without (n=652) the MS were compared with regard to the extent of plaque at baseline and serial change in response to use of medical therapies.
Results: Patients with MS were younger (56+/-9 v 59+/-10 years, p<0.001) and more likely to be female (30 v 24%, p=0.02). Despite this, the presence of MS in these subjects resulted in a similar atheroma burden as that seen in the older subjects without MS. Baseline percent atheroma volume (PAV, 40+/−10 v 40+/−10%, p=0.52), total atheroma volume (TAV, 187+/−82 v 178+/−72 mm3, p=0.09), external elastic membrane volume (225+/−70 v 228+/−67 mm3, p=0.37) and lumen volume (135+/−46 v 137+/−45 mm3, p=0.50) were similar in patients with and without MS. Similarly, PAV and TAV were not greater in MS patients on multivariate analysis. While there was no difference between groups with regard to changes in PAV (0.6+/−4.1 v 0.4+/−3.6%, p=0.42) and TAV (-1.7+/−25.2 v -2.7+/−20.5 mm3, p=0.42), MS patients were more likely to undergo substantial progression (>5% increase in PAV, 31.4 v 25.2%, p=0.01). MS patients were just as likely to undergo substantial plaque regression (>5% decrease in PAV) if the medical therapy they received lowered LDL<80 mg/dL (18 v 17%, p=0.95), systolic blood pressure <120 mmHg (28 v 25%, p=0.48) and CRP <2 mg/L (23 v 21%, p=0.82).
Conclusion: The finding that plaque burden and remodeling did not differ in the setting of MS suggests that other factors may promote the high rate of clinical events. While more patients with MS underwent substantial plaque progression, intensive risk factor modification was just as likely to result in plaque regression in patients with and without MS. This further highlights the benefit of secondary prevention strategies in patients with CAD and MS.