The Effect of Statin Therapy on Coronary Plaque Composition Using Virtual Histology Intravascular Ultrasound: A Meta-Analysis

Additive effects of ezetimibe, evolocumab, and alirocumab on plaque burden and lipid content as assessed by intravascular ultrasound: A PRISMA-compliant meta-analysis

BACKGROUND

The additive effects of ezetimibe, evolocumab or alirocumab on lipid level, plaque volume, and plaque composition using intravascular ultrasound (IVUS) remain unclear.

METHODS

According to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, we performed a systematic review and meta-analysis of trials assessing the effects of ezetimibe, evolocumab, and alirocumab on coronary atherosclerosis using IVUS. The primary outcome was change in total atheroma volume (TAV), and the secondary outcomes were changes and differences in plaque composition and lipid content.

RESULTS

Data were collected from 9 trials, involving 917 patients who received ezetimibe, evolocumab or alirocumab in addition to a statin and 919 patients who received statins alone. The pooled estimate demonstrated a significant reduction in TAV with the addition of ezetimibe and favorable effects of evolocumab and alirocumab on TAV. Subgroup analysis also supported favorable effects of evolocumab and alirocumab on TAV, according to baseline TAV, gender, type 2 diabetes mellitus, and prior stain use. Addition of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to statin therapy resulted in significant reductions in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TG), but not in high-density lipoprotein cholesterol (HDL-C). The pooled estimate also showed significant favorable effects of ezetimibe on LDL-C, TC, and TG, but an insignificant effect on HDL-C. Patients who received ezetimibe showed similar changes in the necrotic core, fibro-fatty plaque, fibrous plaque, and dense calcification compared with patients not treated with ezetimibe.

CONCLUSIONS

The addition of ezetimibe to statin therapy may further reduce plaque and lipid burdens but may not modify plaque composition. Although current evidence supports a similar impact from the addition of PCSK9 inhibitors to statin therapy, more evidence is needed to confirm such an effect.

High-intensity statin treatment is associated with reduced plaque structural stress and remodelling of artery geometry and plaque architecture

Aims

Plaque structural stress (PSS) is a major cause of atherosclerotic plaque rupture and major adverse cardiovascular events (MACE). We examined the predictors of changes in peak and mean PSS (ΔPSSpeak, ΔPSSmean) in three studies of patients receiving either standard medical or high-intensity statin (HIS) treatment.

Methods and results

We examined changes in PSS, plaque size, and composition between 7348 co-registered baseline and follow-up virtual-histology intravascular ultrasound images in patients receiving standard medical treatment (controls, n = 18) or HIS (atorvastatin 80 mg, n = 20, or rosuvastatin 40 mg, n = 22). The relationship between changes in PSSpeak and plaque burden (PB) differed significantly between HIS and control groups (P < 0.001). Notably, PSSpeak increased significantly in control lesions with PB >60% (P = 0.04), but not with HIS treatment. However, ΔPSSpeak correlated poorly with changes in lumen and plaque area or PB, plaque composition, or lipid lowering. In contrast, ΔPSSpeak correlated significantly with changes in lumen curvature, irregularity, and roughness (P < 0.05), all of which were reduced in HIS patients. ΔPSSmean correlated with changes in lumen area, PA, PB, and circumferential calcification, and was unchanged with either treatment.

Conclusion

Our observational study shows that PSSpeak changes over time were associated with baseline disease severity and treatment. The PSSpeak increase seen in advanced lesions with standard treatment was associated with remodelling artery geometry and plaque architecture, but this was not seen after HIS treatment. Smoothing plaques by reducing plaque/lumen roughness, irregularity, and curvature represents a novel mechanism whereby HIS may reduce PSS and, thus may protect against plaque rupture and MACE.

Significant Difference in Acute Coronary Lesions in Patients on Therapeutic Statin Therapy Compared to Those Without

Background Statin therapy has been shown to alter coronary plaque via decreasing lipid-rich pools, substituting with fibrocalcific plaque. We propose that acute coronary lesions in patients on therapeutic statin therapy, compared with patients not on statin therapy with elevated low-density lipoprotein (LDL) levels, will have features typically not associated with lipid-rich disease, such as lengthy fibrocalcific lesions, stent failure (in-stent restenosis and stent thrombosis), and/or bypass graft degeneration. Methods Charts and coronary angiograms of 143 consecutive patients from May 2016 to December 2018 with Type 1 Myocardial Infarction Fourth Universal Definition were retrospectively reviewed. Patients were divided into two groups: group 1, those on statin therapy with an LDL < 100 mg/dL, and group 2, those not on statin therapy with an LDL ≥ 100 mg/dL at the time of an acute coronary syndrome. Acute lesion characteristics and angioplasty techniques/equipment were recorded. Results There were 56 patients in group 1 and 39 patients in group 2. Group 1 patients, compared with group 2, were more likely to have moderate-severe vessel calcification (55.4% vs 10.3%; p < 0.01), lesion length greater than 20 mm (51.8% vs 23.1%; p = 0.019), stent failure (39.3% vs 7.7%; p < 0.01), and bypass graft failure (23.2% vs 7.7%; p = 0.04). Coronary interventions in group 1, compared with group 2, more often required adjunctive angioplasty techniques, including the need for multiple coronary wires, guide extender, thrombectomy, and circulatory support (51.8% vs 7.7%; p < 0.01). There was no significant difference between the number of culprit vessels, including the specific coronary culprit vessel identified between both groups. Conclusion Acute coronary lesions in patients on therapeutic statin therapy, compared to those not on statin therapy with an elevated LDL, tend to be longer, more calcific with increased vessel tortuosity and angulation, as well as from a stent or bypass graft failure mechanism. Furthermore, there is a signal for heightened procedural complexity in the arm with statin therapy. These clinical findings are likely the result of the altered natural history of plaque pathophysiology seen with statin therapy.

Coronary and peripheral artery plaques: do differences in plaque characteristics translate to differences in lipid management?

Optimal medical management of patients with peripheral arterial disease (PAD) includes statin therapy, which has been shown to decrease the risk of major cardiovascular events. However, the relationship between low-density lipoprotein (LDL) lowering, PAD progression and limb outcomes remains controversial. Although prevention of coronary and cerebrovascular events is a priority, limb outcomes are still important determinants of quality of life and healthcare spending. This review will highlight differences between coronary artery disease (CAD) and PAD, and in particular, the more prevalent role of lipids and LDL cholesterol in CAD versus calcification in PAD. This difference may contribute to the differential impact of LDL cholesterol levels on coronary events and outcomes versus limb outcomes. Beyond LDL lowering, immune modulators have emerged as another agent to treat atherosclerosis in CAD, however similar data in PAD are lacking. Small studies have suggested that other lipids besides LDL cholesterol, such as triglycerides or small dense LDL, may have a greater impact on limb outcomes in patients with PAD. Although statin therapy is central in the management of patients with PAD, current understanding of the distinctions between PAD and CAD suggest that there may be other non-LDL targets for risk reduction that require further study.

Effects of long-term statin-treatment on coronary atherosclerosis in patients with inflammatory joint diseases

Background

The effect of statins over time on coronary atherosclerosis in patients with inflammatory joint diseases (IJD) is unknown. Our aim was to evaluate the change in coronary plaque morphology and volume in long-term statin-treated patients with IJD.

Methods

Sixty-eight patients with IJD and carotid artery plaque(s) underwent coronary computed tomography angiography before and after a mean of 4.7 (range 4.0–6.0) years of statin treatment. The treatment target for low density lipoprotein cholesterol (LDL-c) was ≤1.8 mmol/L. Changes in plaque volume (calcified, mixed/soft and total) and coronary artery calcification (CAC) from baseline to follow-up were assessed using the 17-segment American Heart Association-model.

Results

Median (IQR) increase in CAC after statin treatment was 38 (5–236) Agatston units (p<0.001). Calcified and total plaque volume increased with 5.6 (0.0–49.1) and 2.9 (0.0–23.5) mm³, respectively (p<0.001 for both). The median (IQR) change in soft/mixed plaque volume was -10 (-7.1–0.0), p = <0.001. Patients who had obtained the LDL-c treatment target at follow-up, experienced reduced progression of both CAC and total plaque volume compared to patients with LDL-c >1.8mmol/L (21 [2–143] vs. 69 [16–423], p = 0.006 and 0.65 [-1.0–13.9] vs. 13.0 [0.0–60.8] mm³, p = 0.019, respectively).

Conclusions

A progression of total atherosclerotic plaque volume in statin-treated patients with IJD was observed. However, soft/mixed plaque volume was reduced, suggesting an alteration in plaque composition. Patients with recommended LDL-c levels at follow-up had reduced atherosclerotic progression compared to patients with LDL-c levels above the treatment target, suggesting a beneficial effect of treatment to guideline-recommended lipid targets in IJD patients.

Coronary plaque characteristics and epicardial fat tissue in long term survivors of type 1 diabetes identified by coronary computed tomography angiography

OBJECTIVES

The aim was to assess coronary atherosclerosis, plaque morphology and associations to cardiovascular risk factors and epicardial adipose tissue (EAT) in patients with long duration of type 1 diabetes mellitus (T1DM).

MATERIALS AND METHODS

Eighty-eight patients with ≥ 45 year T1DM duration and 60 controls underwent coronary CT angiography (CCTA) for evaluation of coronary artery plaque volume (total, calcified or mixed/soft), coronary artery calcification score (CAC) and EAT.

RESULTS

Plaques were detected in 75 (85%) T1DM patients and 28 (47%) controls, p < 0.01. Median (interquartile range) plaque volume (mm³) in T1DM vs. controls was: 21.0 (1.0-66.0) vs. 0.2 (0.0-7.1), p < 0.01 for calcified, 0.0 (0.0-8.7) vs. 0.0 (0.0-0.0), p < 0.01 for soft/mixed and 29.5 (3.9-95.8) vs. 0.4 (0.0-7.4), p < 0.01 for total plaque volume. Median CAC was 128 (13-671) vs. 1 (0.0-39.0), p < 0.01 in T1DM vs. controls. Median EAT volume did not differ between the groups; 52.3 (36.1-65.5) cm³ vs. 55 (38.3-79.6), p = 0.20. No association between CAC or plaque volumes and EAT were observed. Low time-weighted LDL-cholesterol and HbA1c for 30 years were associated with having plaque volume < 25th percentile, OR (95% CI) 0.18 (0.05-0.70), p = 0.01 and 0.45 (0.20-1.00), p < 0.05, respectively. Time-weighted LDL-c was linearly associated with CAC (beta 0.82 (95% CI 0.03-1.62), p = 0.04) and total plaque volume (beta 0.77 (95% CI 0.19-1.36), p = 0.01).

CONCLUSION

Long-term survivors of T1DM have a higher prevalence of coronary atherosclerosis compared to controls. Low LDL-cholesterol and HbA1c over time have a protective effect on coronary atherosclerosis. EAT volume was not associated with coronary atherosclerosis in T1DM patients.

The high-risk criteria low-attenuation plaque <60 HU and the napkin-ring sign are the most powerful predictors of MACE: a long-term follow-up study

Aims

To assess the prognostic value of coronary CT angiography (CTA) for prediction of major adverse cardiac events (MACE) over a long-term follow-up period.

Methods and Results

A total of 1469 low-to-intermediate-risk patients (65.9 years; 44.2% females) were included in our prospective cohort study. CTA was evaluated for (i) stenosis severity (minimal <10%; mild <50%; moderate 50-70%; severe >70%), (ii) plaque types (calcified, mixed dominantly calcified, mixed dominantly non-calcified, non-calcified), and (iii) high-risk plaque criteria [low-attenuation plaque (LAP) quantified by HU, napkin-ring (NR) sign, spotty calcification <3 mm, and remodelling index (RI)]. Over a follow-up of mean 7.8 years, MACE rate was 41 (2.8%) and 0% in patients with negative CTA. MACE rate increased along with stenosis severity by CTA (from 1.3 to 7.8%) (P < 0.001) and was higher in T3/T4 plaques than in T2/T1 (7.8 vs. 1.9%; P < 0.0001). LAP density was lower (35.2 HU ± 32 vs. 108.8 HU ± 53) (P < 0.001) and both NR-sign prevalence with n = 26 (63.4%) vs. n = 40 (28%) and LAP <30, <60, and <90 HU prevalence with 46.3-78% vs. 2.4-7% were higher in the MACE group (P < 0.001). On univariate and unadjusted multivariable proportional Hazards model, LAP <60 HU and NR were the strongest MACE predictors (HR 4.96; 95% CI: 2.0-12.2 and HR 3.85; 95% CI: 1.7-8.6) (P < 0.0001), while spotty calcification (HR 2.2; 95% CI: 1.1-4.3, P < 0.001), stenosis severity, and plaque type (HR 1.5; 95% CI: 1.1-2.3 and HR 1.7; 95% CI: 1.1-2.6) (P < 0.001) were less powerful. After adjusting for risk factors, CTA stenosis severity, and plaque type, LAP <60 HU and the NR sign remained significant (P < 0.001), while the effect of NR sign was even enhancing. HRP criteria were independent predictors from other risk factors.

Conclusion

Prognosis is excellent over a long-term period if CTA is negative and worsening with an increasing non-calcifying plaque component. LAP <60 HU and NR sign are the most powerful MACE predictors.

What We Have Learned from the Recent Meta-analyses on Diagnostic Methods for Atherosclerotic Plaque Regression

PURPOSE OF REVIEW

Atherosclerosis has major morbidity and mortality implications globally. While it has often been considered an irreversible degenerative process, recent evidence provides compelling proof that atherosclerosis can be reversed. Plaque regression is however difficult to appraise and quantify, with competing diagnostic methods available. Given the potential of evidence synthesis to provide clinical guidance, we aimed to review recent meta-analyses on diagnostic methods for atherosclerotic plaque regression.

RECENT FINDINGS

We identified 8 meta-analyses published between 2015 and 2017, including 79 studies and 14,442 patients, followed for a median of 12 months. They reported on atherosclerotic plaque regression appraised with carotid duplex ultrasound, coronary computed tomography, carotid magnetic resonance, coronary intravascular ultrasound, and coronary optical coherence tomography. Overall, all meta-analyses showed significant atherosclerotic plaque regression with lipid-lowering therapy, with the most notable effects on echogenicity, lipid-rich necrotic core volume, wall/plaque volume, dense calcium volume, and fibrous cap thickness. Significant interactions were found with concomitant changes in low density lipoprotein cholesterol, high density lipoprotein cholesterol, and C-reactive protein levels, and with ethnicity. Atherosclerotic plaque regression and conversion to a stable phenotype is possible with intensive medical therapy and can be demonstrated in patients using a variety of non-invasive and invasive imaging modalities.

Relationship Between Serum Inflammatory Marker Levels and the Dynamic Changes in Coronary Plaque Characteristics After Statin Therapy

BACKGROUND

The mechanism of statin for atheroma stabilization remains unclear. We aimed to assess the relationship between on-treatment changes in serum inflammatory biomarker levels and plaque composition in differed nonculprit coronary lesions.

METHODS AND RESULTS

The changes in serum biochemical values, and intravascular ultrasound data were evaluated in 218 patients with virtual histology (VH)-intravascular ultrasound-defined fibroatheroma-containing segments after 12-month rosuvastatin treatment. When stratifying patients into quartiles according to the change in high-sensitivity C-reactive protein (hsCRP), there was a significant positive linear relationship for the changes in %necrotic core (coefficient, 1.31; standard error, 0.54) and %dense calcium volumes (coefficient, 0.80; standard error, 0.27), but a negative linear relationship for the changes in %fibrous (coefficient, -0.94; standard error, 0.45) and %fibrofatty volumes (coefficient, -1.17; standard error, 0.56; all P<0.05). The decrease in hsCRP (-1.2±3.9 versus 0.5±3.4 mg/L; P=0.02) was greater in those without VH-defined thin-cap fibroatheroma (TCFA, defined as >30° of necrotic core abutting the lumen in 3 consecutive slices) than those with VH-TCFA at follow-up. Diabetes mellitus, a larger normalized total atheroma volume, and the presence of VH-TCFA at baseline predicted the presence of VH-TCFA at follow-up (odds ratio, 4.01, 1.18, and 9.21, respectively; all P<0.05), whereas the change in hsCRP showed a trend (odds ratio, 1.19; P=0.07). The change in low-density lipoprotein-cholesterol had no relationship with the changes in hsCRP or plaque compositions.

CONCLUSIONS

With 12-month rosuvastatin therapy, a greater hsCRP reduction (not low-density lipoprotein-cholesterol) was associated with a greater decrease in %necrotic core volume and the absence of VH-TCFA, indicating a link between the anti-inflammatory action of statin and plaque stabilization by reducing NC and reinforcing fibrous cap.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00997880.

Previous Statin Use and High-Resolution Magnetic Resonance Imaging Characteristics of Intracranial Atherosclerotic Plaque: The Intensive Statin Treatment in Acute Ischemic Stroke Patients With Intracranial Atherosclerosis Study

BACKGROUND AND PURPOSE

Although statin use has been linked to the stabilization of systemic atherosclerosis, its effect on symptomatic intracranial atherosclerotic plaques has yet to be explored. We hypothesized that premorbid statin use is associated with plaque instability in intracranial arteries and may lead to differential patterns (size and distribution) of ischemic lesions in patients with acute intracranial atherosclerotic stroke.

METHODS

One hundred and thirty-six patients with acute infarcts caused by intracranial atherosclerotic stroke underwent high-resolution magnetic resonance imaging. Patients were categorized into 3 groups based on their premorbid statin use: nonuser, low-dose user, and high-dose user, according to the 2013 American College of Cardiology/American Heart Association guidelines on blood cholesterol. Symptomatic lesions in intracranial arteries were analyzed using high-resolution magnetic resonance imaging for vascular morphology (degree of stenosis, remodeling index, and wall index) and plaque activation (pattern and volume of enhancement). The cortical distribution and volume of ischemic brain lesions were measured using diffusion-weighted imaging.

RESULTS

Among the enrolled patients, 38 (27.94%) were taking statins before the index stroke (22 low-dose statins and 16 high-dose statins). The degree of stenosis, remodeling index, and wall index did not differ between the 3 groups. However, the volume of plaque enhancement was significantly lower in statin users (nonuser, 33.26±40.72; low-dose user, 13.15±17.53; high-dose user, 3.13±5.26; P=0.002). Premorbid statin use was associated with a higher prevalence of nonembolic stroke and a decrease in large cortical infarcts (P=0.012).

CONCLUSIONS

Premorbid statin usage is independently associated with reduced plaque enhancement and a decrease in large cortical lesions in patients with intracranial atherosclerotic stroke.

Changes of coronary plaque composition correlate with C-reactive protein levels in patients with ST-elevation myocardial infarction following high-intensity statin therapy

OBJECTIVES

Levels of inflammatory biomarkers associate with changes of coronary atheroma burden in statin-treated patients with stable coronary artery disease. This study sought to determine changes of plaque composition in vivo in relation to high-sensitivity C-reactive protein (hs-CRP) levels in patients with ST-elevation myocardial infarction (STEMI) receiving high-intensity statin therapy.

METHODS

The IBIS-4 study performed serial (baseline and 13-month), 2-vessel intravascular ultrasound (IVUS) and radiofrequency-IVUS of the non-infarct-related arteries in patients with STEMI treated with high-intensity statin therapy. The present analysis included 44 patients (80 arteries) with serial measurements of hs-CRP.

RESULTS

At follow-up, median low-density lipoprotein cholesterol (LDL-C) levels decreased from 126 to 77 mg/dl, HDL-C increased from 44 to 47 mg/dl, and hs-CRP decreased from 1.6 to 0.7 mg/L. Regression of percent atheroma volume (-0.99%, 95% CI -1.84 to -0.14, p = 0.024) was accompanied by reduction of percent fibro-fatty (p = 0.04) and fibrous tissue (p < 0.001), and increase in percent necrotic core (p = 0.006) and dense calcium (p < 0.001). Follow-up levels of hs-CRP, but not LDL-C, correlated with changes in percent necrotic core (p = 0.001) and inversely with percent fibrous tissue volume (p = 0.008). Similarly, baseline-to-follow-up change of hs-CRP correlated with the change in percent necrotic core volume (p = 0.02).

CONCLUSIONS

In STEMI patients receiving high-intensity statin therapy, stabilization of VH-IVUS-defined necrotic core was confined to patients with lowest on-treatment levels and greatest reduction of hs-CRP. Elevated CRP levels at follow-up may identify progression of high-risk coronary plaque composition despite intensive statin therapy and overall regression of atheroma volume.