Three-dimensional morphological response of lipid-rich coronary plaques to statin therapy: a serial optical coherence tomography study

Effect of Intensive Lipid-Lowering Therapy on Coronary Plaque Stabilization Derived from Optical Coherence Tomography: a Meta-analysis and Meta-regression

PURPOSE

The definitive impacts of intensive lipid-lowering therapy (LLT) on plaque stabilization and the relationship between the key markers during LLT and plaque stability remain unquestioned. Thus, these meta-analysis and meta-regression intend to holistically evaluate the influence exerted by rigorous LLT on the minimum fibrous cap thickness (FCT) and maximum lipid arc as discerned through optical coherence tomography (OCT). This study further scrutinizes the correlation of this impact with variations in high-sensitivity C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C), or additional parameters within patients diagnosed with coronary artery disease (CAD).

METHODS

Comprehensive searches were conducted on platforms including PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) published until June 1, 2023. The search was language agnostic and targeted RCTs elaborating on the correlation between high-intensity statin therapy or statins used concomitantly with other lipid-lowering medications and the minimum FCT and maximum lipid arc as assessed by OCT. The meta-analyses were executed employing a standard mean difference (SMD) algorithm with random-effects on continuous variables. These methodologies align with the Preferred Reporting Items for Systematic and Meta-analysis (PRISMA) guidelines.

RESULTS

A spectrum of 12 RCTs engaging 972 patients were identified and mobilized for these analyses. Meta-analysis outcomes depicted a conspicuous correlation between intensive LLT and an enhanced minimum FCT (12 studies with 972 participants; SMD, 0.87; 95% CI, 0.54 to 1.21; P < 0.01), reduced maximum lipid arc (9 studies with 564 participants; SMD, -0.43; 95% CI, -0.58 to -0.29; P < 0.01). Meta-regression analysis has determined an association of elevated minimum FCT with decreased LDL-C (β, -0.0157; 95% CI, -0.0292 to -0.0023; P = 0.025), total cholesterol (TC) (β, -0.0154; 95% CI, -0.0303 to -0.0005; P = 0.044), and apolipoprotein B (ApoB) (β, -0.0209; 95% CI, -0.0361 to -0.0057; P = 0.022). However, no significant association was discerned relative to variations in hs-CRP/CRP (β, -0.1518; 95% CI, -1.3766 to -1.0730; P = 0.772), triglyceride (TG) (β, -0.0030; 95% CI, -0.0258 to -0.0318; P = 0.822), and high-density lipoprotein cholesterol (HDL-C) (β, 0.0313; 95% CI, -0.0965 to 0.1590; P = 0.608). Subsequent subgroup meta-analysis demonstrated that high-intensity statin therapy (5 studies with 204 participants; SMD, 1.03; 95% CI, 0.67 to 1.39; P < 0.01), as well as a combinative approach including PCSK9 antibodies and statins (3 studies with 522 participants; SMD, 1.17; 95% CI, 0.62 to 1.73; P < 0.01) contributed to an increase in minimum FCT. Parallelly, high-intensity statin therapy (4 studies with 183 participants; SMD, -0.42; 95% CI, -0.65 to -0.19; P < 0.01) or the combined application of PCSK9 antibodies and statins (2 studies with 222 participants; SMD, -0.98; 95% CI, -1.26 to -0.70; P < 0.01) was evidenced to decrease the maximum lipid arc.

CONCLUSIONS

Intensive LLT, mainly high-intensity statin therapy and combined PCSK9 antibody with statin, has a beneficial effect on coronary plaque stabilization derived from OCT in patients with CAD. Coronary plaque stabilization is primarily due to lipid-lowering effect, not anti-inflammatory effect. Moreover, the lipid-lowering effect has nothing to do with the changes in HDL-C and TG, but is mainly related to the reduction of LDL-C, TC, and ApoB.

Intensive statin versus low-dose statin + ezetimibe treatment for fibrous cap thickness of coronary vulnerable plaques

BACKGROUND

Acute coronary syndromes mainly result from abrupt thrombotic occlusion caused by atherosclerotic vulnerable plaques (VPs) that suddenly rupture or erosion. Fibrous cap thickness (FCT) is a major determinant of the propensity of a VP to rupture and is recognized as a key factor. The intensive use of statins is known to have the ability to increase FCT; however, there is a risk of additional adverse effects. However, lower dose statin with ezetimibe is known to be tolerable by patients. The present study aimed to investigate the effect of intensive statin vs. low-dose stain + ezetimibe therapy on FCT, as evaluated using optical coherence tomography.

METHOD

Patients who had VPs (minimum FCT <65 μm and lipid core >90°) and deferred from intervention in our single center from January 2014 to December 2018 were included in the trial. They were divided into the following two groups: intensive statin group (rosuvastatin 15-20 mg or atorvastatin 30-40 mg) and combination therapy group (rosuvastatin 5-10 mg or atorvastatin 10-20 mg + ezetimibe 10 mg). At the 12-month follow-up, we compared the change in the FCT (ΔFCT%) between the two groups and analyzed the association of ΔFCT% with risk factors. Fisher exact test was used for all categorical variables. Student's t test or Mann-Whitney U-test was used for analyzing the continuous data. The relationship between ΔFCT% and risk factors was analyzed using linear regression analysis.

RESULT

Total 53 patients were finally enrolled, including 26 patients who were in the intensive statin group and 27 who were in the combination therapy group. At the 12-month follow-up, the serum levels of total cholesterol (TC), total triglyceride, low-density lipoprotein (LDL-C), hypersensitive C-reactive protein (hs-CRP), and lipoprotein-associated phospholipase A2 (Lp-PLA2) levels were reduced in both the groups. The ΔTC%, ΔLDL-C%, and ΔLp-PLA2% were decreased further in the combination therapy group. FCT was increased in both the groups (combination treatment group vs. intensive statin group: 128.89 ± 7.64 vs. 110.19 ± 7.00 μm, t = -9.282, P < 0.001) at the 12-month follow-up. The increase in ΔFCT% was more in the combination therapy group (123.46% ± 14.05% vs. 91.14% ± 11.68%, t = -9.085, P < 0.001). Based on the multivariate linear regression analysis, only the serum Lp-PLA2 at the 12-month follow-up (B = -0.203, t = -2.701, P = 0.010), ΔTC% (B = -0.573, t = -2.048, P = 0.046), and Δhs-CRP% (B = -0.302, t = -2.963, P = 0.005) showed an independent association with ΔFCT%.

CONCLUSIONS

Low-dose statin combined with ezetimibe therapy maybe provide a profound and significant increase in FCT as compared to intensive statin monotherapy. The reductions in Lp-PLA2, ΔTC%, and Δhs-CRP% are independently associated with an increase in FCT.

Optical Coherence Tomography Predictors for a Favorable Vascular Response to Statin Therapy

Background

Specific plaque phenotypes that predict a favorable response to statin therapy have not been systematically studied. This study aimed to identify optical coherence tomography predictors for a favorable vascular response to statin therapy.

Methods and Results

Patients who had serial optical coherence tomography imaging at baseline and at 6 months were included. Thin‐cap area (defined as an area with fibrous cap thickness <200 μm) was measured using a 3‐dimensional computer‐aided algorithm, and changes in the thin‐cap area at 6 months were calculated. A favorable vascular response was defined as the highest tertile in the degree of reduction of the thin‐cap area. Macrophage index was defined as the product of the average macrophage arc and length of the lesion with macrophage infiltration. Layered plaque was defined as a plaque with 1 or more layers of different optical density. In 84 patients, 140 nonculprit lipid plaques were identified. In multivariable analysis, baseline thin‐cap area (odds ratio [OR] 1.442; 95% CI, 1.024–2.031, P=0.036), macrophage index (OR, 1.031; 95% CI, 1.002–1.061, P=0.036), and layered plaque (OR, 2.767; 95% CI, 1.024–7.479, P=0.045) were identified as the significant predictors for a favorable vascular response. Favorable vascular response was associated with a decrease in the macrophage index.

Conclusions

Three optical coherence tomography predictors for a favorable vascular response to statin therapy have been identified: large thin‐cap area, high macrophage index, and layered plaque. Favorable vascular response to statin was correlated with signs of decreased inflammation.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01110538.

A transcriptomic model to predict increase in fibrous cap thickness in response to high-dose statin treatment: Validation by serial intracoronary OCT imaging

Background

Fibrous cap thickness (FCT), best measured by intravascular optical coherence tomography (OCT), is the most important determinant of plaque rupture in the coronary arteries. Statin treatment increases FCT and thus reduces the likelihood of acute coronary events. However, substantial statin-related FCT increase occurs in only a subset of patients. Currently, there are no methods to predict which patients will benefit. We use transcriptomic data from a clinical trial of rosuvastatin to predict if a patient's FCT will increase in response to statin therapy.

Methods

FCT was measured using OCT in 69 patients at (1) baseline and (2) after 8–10 weeks of 40  mg rosuvastatin. Peripheral blood mononuclear cells were assayed via microarray. We constructed machine learning models with baseline gene expression data to predict change in FCT. Finally, we ascertained the biological functions of the most predictive transcriptomic markers.

Findings

Machine learning models were able to predict FCT responders using baseline gene expression with high fidelity (Classification AUC = 0.969 and 0.972). The first model (elastic net) using 73 genes had an accuracy of 92.8%, sensitivity of 94.1%, and specificity of 91.4%. The second model (KTSP) using 18 genes has an accuracy of 95.7%, sensitivity of 94.3%, and specificity of 97.1%. We found 58 enriched gene ontology terms, including many involved with immune cell function and cholesterol biometabolism.

Interpretation

In this pilot study, transcriptomic models could predict if FCT increased following 8–10 weeks of rosuvastatin. These findings may have significance for therapy selection and could supplement invasive imaging modalities.

Effect of Statin Therapy on Fibrous Cap Thickness in Coronary Plaque on Optical Coherence Tomography - Review and Meta-Analysis

BACKGROUND

Statin therapy has been shown to result in coronary plaque regression, but the relationship between statin use and stabilization of coronary plaque has not been elucidated. We conducted a systematic review and meta-analysis to evaluate the effect of statin therapy on fibrous cap thickness (FCT) on optical coherence tomography (OCT).Methods and Results:Nine OCT studies (6 randomized controlled trials and 3 observational studies) were enrolled with a total of 341 patients (390 lesions). Arms of the studies were grouped according to statin type and/or dose. Random effects meta-analysis was used to estimate a pooled mean change in FCT from baseline to follow-up. The overall effect mean FCT change was 67.7 µm (95% CI: 51.4-84.1, I²=95.0%, P<0.001). All statin groups had an increase in FCT, but the magnitude of the increase differed according to the statin. Two homogeneous subgroups with I²=0 were identified: mean FCT change was 27.8 µm (for subgroup atorvastatin 5 mg and rosuvastatin), and 61.9 µm (for subgroup atorvastatin 20 mg, fluvastatin 30 mg, and pitavastatin 4 mg). On meta-regression modeling, statin therapy alone explained most of the change in FCT.

CONCLUSIONS

Statin therapy induced a significant increase in FCT as assessed on OCT, independent of coronary risk factors and other medications.

Comparison of Vascular Response to Statin Therapy in Patients With Versus Without Diabetes Mellitus

Diabetes mellitus (DM) increases cardiovascular morbidity and mortality. A statin is routinely prescribed to patients with DM. However, whether a statin therapy is equally effective in plaque stabilization in DM patients compared with non-DM patients is unknown. A total of 117 lipid-rich plaques were imaged in 90 patients (54 plaques in 41 DM patients and 63 plaques in 49 non-DM patients) with coronary artery disease, those who were treated with a statin and underwent serial optical coherence tomography imaging were included in this study (mean follow-up period, 362 ± 38 days). The changes in minimum fibrous cap thickness (FCT) and lipid index between baseline and 1-year follow-up were compared between the 2 groups. Minimum FCT increased and lipid index decreased with statin therapy in both groups. No significant differences were observed in percent changes of minimum FCT (p = 0.796) and lipid index (p = 0.336) between DM and non-DM patients. Statin therapy induced a significant increase in FCT and a significant decrease in lipid index in both groups. Vascular response to statin therapy was similar between the 2 groups irrespective of DM status.

Healthcare provider compliance with the 2013 ACC/AHA Adult Cholesterol Guideline recommendation for high-intensity dose statins for patients with coronary artery disease

BACKGROUND

Atherosclerotic cardiovascular disease is the foremost cause of death for U.S. adults. The 2013 ACC/AHA Adult Cholesterol Guidelines recommend high-intensity dose statins for individuals with coronary artery disease (CAD).

OBJECTIVE

To determine healthcare provider compliance with the Cholesterol Guideline recommendation specific to high-intensity dose statins for patients with CAD.

METHODS

A retrospective chart review was conducted to determine compliance rate. A questionnaire was developed to evaluate healthcare provider beliefs, attitudes, and self-confidence toward this recommendation.

RESULTS

Of the 473 patients with CAD, 67% were prescribed a high-intensity dose statin. Patients with non-ST segment myocardial infarction and ST segment myocardial infarction were more likely to be prescribed a high-intensity dose statin versus a moderate or low-intensity dose. Healthcare providers strongly agreed with this guideline recommendation.

CONCLUSION

There exists a dichotomy between intention to prescribe and actual prescribing behaviors of high-intensity dose statin for patients with CAD.