Association of small dense LDL cholesterol and inflammation with plaque rupture in acute coronary syndrome: An OCT...

Plaque rupture (PR) is the predominant cause of acute coronary syndrome (ACS). Small dense low-density lipoprotein cholesterol (sd-LDL-C) shows a greater association with cardiovascular event risk than LDL-C. To better understand the contributions of atherogenic lipids and systemic inflammation, we investigated the association of sd-LDL-C and high-sensitivity C-reactive protein (hs-CRP) with PR in patients with ACS.

We enrolled 315 consecutive patients with ACS who underwent optical coherence tomography-guided emergency percutaneous coronary intervention. Culprit lesions were classified as PR or intact fibrous cap (IFC). The IFC group was further subdivided into plaque erosion (PE) and other IFC. Serum samples were collected before coronary angiography.

Among 315 patients (PR: n = 164; IFC: n = 151 [PE: 92, other: 59]), sd-LDL-C was significantly higher in patients with PR than in those with PE and other IFC groups (38.8 vs 31.6 vs 27.6 mg/dL; P = 0.042), despite similar LDL-C levels. In multivariable logistic regression analysis, continuous hs-CRP was independently associated with PR, whereas continuous sd-LDL-C was not; however, categorical analyses suggested higher odds for PR in the upper quartiles of both markers. Furthermore, the combined high sd-LDL-C/high hs-CRP group (above medians) carried the highest PR risk (OR 3.87, 95% CI 1.99-7.92; P < 0.001) compared with the low/low group.

Elevated sd-LDL-C and hs-CRP are independently associated with PR in the culprit lesion. A combined assessment of atherogenic lipids and systemic inflammation may identify individuals with a residual risk for PR beyond LDL-C values.