Impact of vessel curvature on neointimal healing after stent implantation as assessed by optical coherence tomography.

PURPOSE: Previous studies have indicated that stent implantation could alter the vessel geometry, which may impact the neointimal healing process. Curvature is an important parameter for evaluating vessel geometry. The purpose of our study was to investigate the relationship between vessel curvature and neointimal healing after stent implantation. METHODS: Fifty-nine patients with acute coronary syndrome (ACS) who underwent stent implantation were enrolled in the study. According to the post-percutaneous coronary intervention vessel curvature measured by quantitative coronary angiography, patients were divided into high (n = 30) and low (n = 29) curvature groups. Neointimal thickness and area together with the neointimal type were assessed by optical coherence tomography at a 6-month follow-up. RESULTS: Baseline clinical characteristics were comparable between the 2 groups. The vessel curvature at pre- and 6-month follow-up was significantly higher in the high curvature group than the low curvature group. At 6-month follow-up, neointimal thickness (0.22 [0.08-0.32] mm vs. 0.10 [0.07-0.16] mm, P = .043) and neointimal area (1.86 [0.66-2.66] vs. 0.82 [0.60-1.41] mm, P = .030) were significantly higher in the high curvature group than the low curvature group. In the high curvature group, the incidence of the heterogeneous neointimal type was higher than that in the low curvature group (50.00% vs. 17.20%, respectively, P = .004), whereas the frequency of the homogeneous neointimal type was lower (43.30% vs. 82.80%, respectively, P = .004) in the high curvature group than the low curvature group. CONCLUSION: Higher vessel curvature after stent implantation may potentially have an impact on the neointimal healing with a higher incidence of heterogeneous neointimal.

Impact of statins therapy on morphological changes in lipid-rich plaques stratified by 10-Year framingham risk score: A serial optical coherence tomography study.

The aim of the study was to investigate the impact of statins therapy on morphological changes of lipid-rich plaques by OCT (optical coherence tomography) in patients with known CHD (coronary heart disease), stratified by FRS. Ninety-seven lipid-rich plaques from sixty-nine patients who received statins therapy and underwent serial OCT images (baseline, 6-month and 12-month) were divided into 2 groups according to the FRS (framingham risk score): low risk group A (FRS<10%, N=35, n=45), moderate to high risk group B (FRS≥10%, N=34, n=52). Fibrous cap thickness (FCT) was measured at its thinnest part 3 times. Baseline characteristics were not different between the 2 groups. FCT sustained increased from baseline to 6-month and 12-month follow up in both group A (59.8±20.4µm, 118.3±62.5µm, and 158.8±83.4µm respectively, P<0.001) and group B (62.2±16.8µm, 125.1±78.7µm, 163.8±75.5µm respectively, P<0.001). Lipid index was significantly decreased in both group A (1862.1±1164.5, 1530.3±1108.7, 1322.9±1080.4, P<0.001) and group B (1646.6±958.5, 1535.1±1049.1, 1258.6±1045, P=0.016). The incidence of TCFA was decreased statistically in both group A (P <0.001) and group B (P <0.001). The patients with known CHD can equivalently benefit from statins therapy by stabilizing the lipid-rich plaques. Patients with moderate to high FRS might benefit more within the first year from event time.

Management and Outcome of Patients With Acute Coronary Syndrome Caused by Plaque Rupture Versus Plaque Erosion: An Intravascular Optical Coherence Tomography Study.

BACKGROUND: Plaque rupture and erosion are the 2 most common mechanisms for acute coronary syndromes. However, the outcome of these 2 distinct pathologies in patients with acute coronary syndromes has never been studied. METHODS AND RESULTS: We retrospectively studied 141 patients with acute coronary syndromes who underwent optical coherence tomography (OCT) imaging of the culprit lesion prior to stenting from the Massachusetts General Hospital OCT Registry. Management (stent versus no stent), poststent OCT findings, and outcomes were compared. Among the 141 culprit lesions, rupture was found in 79 (56%) patients and erosion in 62 (44%). Stent implantation was performed in 77 (97.5%) patients with rupture versus 49 (79.0%) in those with erosion (P<0.001). Immediately after percutaneous coronary intervention, OCT showed a higher incidence of malapposition (37.5% versus 7.3%, P<0.001), thrombus (59.4% versus 14.6%, P<0.001), and protrusion (93.8% versus 73.2%, P=0.008) in the rupture group compared with the erosion group. Plaque rupture was associated with a higher incidence of no reflow or slow flow and distal embolization. Although cardiac event rates were comparable between the two groups at the 1-year follow-up, none of the erosion patients who were treated conservatively without stenting had adverse cardiac events. CONCLUSIONS: Unfavorable poststent OCT findings were more frequent in rupture patients compared with erosion patients. A subset of erosion patients who were treated conservatively without stenting remained free of adverse cardiac events for up to 1 year.

Chronic kidney disease predicts coronary plaque vulnerability: an optical coherence tomography study.

OBJECTIVE: The addition of cystatin C to creatinine in calculating the estimated glomerular filtration rate (eGFR) is known to improve the risk prediction for cardiovascular events. We sought to investigate the associations between eGFRs calculated by three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations and coronary plaque phenotype by optical coherence tomography. PATIENTS AND METHODS: We analyzed 181 nonculprit plaques from 116 coronary artery disease patients. For each patient, the eGFR was calculated using the CKD-EPIcreatinine, CKD-EPIcystatin C, and CKD-EPIcombination equations. Patients were divided into three categories according to the eGFR calculated by each equation (≥90, 60-89, and <60 ml/min/1.73 m). RESULTS: The prevalence of thin-cap fibroatheroma (TCFA) was correlated inversely with eGFR calculated using CKD-EPIcystatin C and CKD-EPIcombination equations, but not using the CKD-EPIcreatinine equation. The best cut-off values of eGFR calculated by these two equations for differentiating TCFA were 83 and 84 ml/min/1.73 m, respectively. Compared with the CKD-EPIcreatinine equation, patients who were reclassified upward or downward categories by the CKD-EPIcystatin C equation were associated with consistently lower [adjusted odds ratio=0.27, 95% confidence interval (CI), 0.08-0.86] and higher (adjusted odds ratio=2.41, 95% CI, 1.08-5.41) prevalence for TCFA, respectively. The net reclassification improvement with cystatin C, compared with creatinine, was 0.45 (95% CI, 0.20-0.69) for TCFA, 0.38 (95% CI, 0.09-0.67) for thrombus, and 0.21 (95% CI, 0.00-0.42) for cholesterol crystals. Results were generally similar for the CKD-EPIcombination equation. CONCLUSION: The use of cystatin C alone or in combination with creatinine, compared with creatinine alone, for GFR estimation strengthens the associations between the eGFR and prevalence of vulnerable plaque characteristics.