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Plaque rupture (PR), characterized by a disruption of the fibrous cap of lipid-rich plaques, is the major etiology of ST-segment elevation myocardial infarction (STEMI). Dyslipidemia is a well-known risk factor for PR. Nonetheless, the impact of detailed atherogenic lipid profiles, including small dense low-density lipoprotein cholesterol (sd-LDL-C) and triglyceride-rich lipoproteins (TRLs), on PR has not yet been investigated.To elucidate the impact of sd-LDL-C and TRL levels on PR in patients with STEMI using optical coherence tomography (OCT).A total of 106 consecutive statin-naive patients with STEMI were enrolled. The PR in culprit lesions was assessed on pre-intervention OCT images, and serum samples were collected immediately before coronary angiography. Sd-LDL-C was directly measured using a homogeneous assay. TRL-cholesterol (TRL-C) was estimated by subtracting the LDL-C level from the non-high-density lipoprotein cholesterol level. Clinical characteristics and lipid profiles were compared between the PR and intact fibrous cap (IFC).No difference in LDL-C levels was observed between the PR (n=64) and IFC (n=42) groups (120.0 mg/dL vs. 129.5 mg/dL, p=0.97); however, sd-LDL-C levels were significantly higher in the PR group (38.9 mg/dL vs. 32.4 mg/dL, p=0.04). Similarly, the PR group had higher TRL-C (24.0 mg/dL vs. 18.0 mg/dL, p=0.01) and triglyceride (130.0 mg/dL vs. 100.3 mg/dL, p=0.03) levels than the IFC group. Multivariate logistic regression analysis showed that sd-LDL-C was an independent factor determining PR (odds ratio, 1.53 per 10 mg/dL; p=0.04).Only sd-LDL-C levels were significantly associated with PR in culprit lesions in patients with STEMI.

The presence of cholesterol crystals (CCs) is recognized as a component of vulnerable atherosclerotic plaques at risk of rupture. The phagocytosis of atherogenic lipid factors by macrophages precedes and promotes the formation of vulnerable plaques, but it is not clear how these factors affect the formation of CC.This study aimed to evaluate the relationship between lipid biomarkers such as small dense low-density lipoprotein cholesterol (sd-LDL-c) and CC detected by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS).Serum samples were collected immediately before coronary angiography in consecutive 174 patients with ACS who did not take statins and underwent OCT imaging of the culprit lesion. The sd-LDL-c levels were measured using a direct homogenous assay. CC was defined as a thin linear structure with high reflectivity and low signal attenuation on the OCT images.CC was identified in 85 patients (48.9%). The prevalence of CC was significantly higher in lesions with ruptured plaques and greater macrophage grade. The sd-LDL-c levels were significantly higher in the patients with CC (41.6 vs. 31.2 mg/dL, p = 0.01) although there were no significant differences in the levels of LDL-c and apolipoprotein B. The CC group also had higher levels of apolipoprotein C3 and HbA1c levels. In multiple logistic regression analysis, sd-LDL-c was an independent risk factor of CC (odds ratio, 1.19 per 10 mg/dL; p = 0.03).sd-LDL may play an important role in the presence of CC in patients with ACS.

A 58-year-old woman with pallor on her left hand due to chronic hemodialysis presented with a recent intractable skin ulcer on her left 3rd finger; the skin perfusion pressure (SPP) was 19 mmHg. Preoperative angiography revealed an occluded proximal left radial artery, no communication between the ulnar and superficial palmar arteries, several collaterals from the left ulnar to the radial artery, and no visualization of the finger arteries. Successful endovascular therapy to the occluded radial artery increased flow to the arteriovenous fistula (AVF), but not to the fingertips. Slightly compressing the AVF augmented the flow and wound blush at the wound sites on the 3rd fingertip, leading to a diagnosis of hemodialysis access-induced distal ischemia (HAIDI). Surgical AVF banding with intra-operative SPP monitoring improved the SPP to 34 mmHg, leading to complete wound healing over 1 month with a preserved AVF. We performed a bilateral temporal artery biopsy and diagnosed giant cell arteritis. As the angiographic wound blush at wound sites is reportedly an important factor for wound healing, angiography with AVF manual compression is essential to diagnose HAIDI and evaluate the blood flow for wound healing.