Clinical Predictors for Lack of Favorable Vascular Response to Statin Therapy in Patients With Coronary Artery Disease: A Serial Optical Coherence Tomography Study

Drug intervention as an emerging concept for secondary prevention in patients with coronary disease

Non-culprit lesion-related coronary events are a significant concern in patients with coronary artery disease (CAD) undergoing coronary intervention. Since several studies using intra-coronary imaging modalities have reported a high prevalence of vulnerable plaques in non-culprit lesions at the initial coronary event, the immediate stabilization of these plaques by intensive pharmacological regimens may contribute to the reduction in the adverse events. Although current treatment guidelines recommend the titration of statin and other drugs to attain the treatment goal of low-density lipoprotein cholesterol (LDL-C) level in patients with CAD, the early prescription of strong LDL-C lowering drugs with more intensive regimen may further reduce the incidence of recurrent cardiovascular events. In fact, several studies with intensive regimen have demonstrated a higher percentage of patients with the attainment of LDL-C treatment goal in the early phase following discharge. In addition to many imaging studies showing plaque stabilization by LDL-C lowering drugs, several recent reports have shown the efficacy of early statin and proprotein convertase subtilisin/kexin type 9 inhibitors on the immediate stabilization of non-culprit coronary plaques. To raise awareness regarding this important concept of immediate plaque stabilization and subsequent reduction in the incidence of recurrent coronary events, the term 'Drug Intervention' has been introduced and gradually applied in the clinical field, although a clear definition is lacking. The main target of this concept is patients with acute coronary syndrome as a higher prevalence of vulnerable plaques in non-culprit lesions in addition to the worse clinical outcomes has been reported in recent imaging studies. In this article, we discuss the backgrounds and the concept of drug intervention.

Residual Coronary Risk Factors Associated With Long-Term Clinical Outcomes in Patients With Coronary Artery Disease Treated With High- vs. Low-Dose Statin Therapy - REAL-CAD Substudy

BACKGROUND

It remains unclear which comorbidities, other than lipid parameters, or combination of comorbidities, best predicts cardiovascular events in patients with known coronary artery disease (CAD) treated with statins. Therefore, we aimed to identify the nonlipid-related prognostic factors and risk stratification of patients with stable CAD enrolled in the REAL-CAD study.

METHODS AND RESULTS

Blood pressure, glucose level, and renal function were considered as risk factors in the 11,141 enrolled patients. The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, and unstable angina. The secondary composite endpoint was the primary endpoint and/or coronary revascularization. A significantly worse prognosis at the primary endpoint was observed in the estimated glomerular filtration rate (eGFR) ≤60 group, and the combination of eGFR ≤60 and HbA1c ≥6.0 was the worst (hazard ratio (HR) 1.66; P<0.001). However, even in the eGFR >60 group, systolic blood pressure (SBP) ≥140 mmHg met the secondary endpoint (HR 1.33; P=0.006), and the combination of eGFR ≤60 and HbA1c ≥6.0 was also the worst at the secondary endpoint (HR 1.35; P=0.002).

CONCLUSIONS

Regarding nonlipid prognostic factors contributing to the incidence of cardiovascular events in statin-treated CAD patients, renal dysfunction was the most significant, followed by poor glucose control and high SBP.

Potent platelet inhibition with peri-procedural tirofiban may attenuate progression of atherosclerosis in patients with acute coronary syndromes

Organization of platelet-rich thrombus at the site of plaque disruption may contribute to rapid progression of atherosclerosis. This study was conducted to investigate if potent platelet inhibition therapy in patients with acute coronary syndromes (ACS) mitigates plaque progression. Patients enrolled in the EROSION study who presented with ACS caused by plaque erosion and underwent serial imaging of the culprit lesion by optical coherence tomography at baseline, 1 month, and 1 year were included. Among 49 patients, 32 (65.3%) patients were treated with glycoprotein IIb/IIIa inhibitor (GPI) in addition to aspirin and ticagrelor. The increase in area stenosis from baseline to 1-year follow-up was significantly smaller in patients treated with GPI, compared to those without GPI therapy (4.8% [- 1.6 to 10.9] vs. 9.6% [4.0 to 21.3], p = 0.031). The cohort was divided into 2 groups based on culprit lesion phenotype at 1 year: Group A, new layer formation at 1-year that was not present at baseline (n = 18); Group B, no new layer formation (n = 31). A new layer was less frequently found at 1 year in patients treated with GPI than in those without GPI (25.0% vs. 58.8%, p = 0.019). Group A, compared to Group B, was associated with a greater increase in area stenosis (19.0 ± 16.4% vs. 3.7 ± 7.1%; p < 0.001). Potent platelet inhibition with GPI in patients with ACS caused by plaque erosion was associated with lower incidence of new layer formation and less plaque progression.

Can OCT change the therapeutic strategy in ACS due to plaque erosion?

The pathophysiology of acute coronary syndromes was thought to be coronary thrombosis over a plaque rupture. Autopsy studies revealed that not all cases were due to plaque rupture, even denuded endothelium or calcific nodule can beget a thrombus. Introduction of OCT made, in vivo recognition of lesion morphology clear. Plaque ruptures are most common and need primary angioplasty. Recent studies established plaque erosion is responsible for ACS in one third of the cases and majority of them present as Non ST elevation myocardial infarction and commonly found in young patients without major risk factors. Evidence from recent studies suggested that stenting can be deferred and they can be managed conservatively with good long term outcomes. More randomized trials are needed comparing plaque rupture and plaque erosion as regards conservative versus invasive management. If these studies substantiate the concept of conservative management, it will lead to a paradigm shift in their management.

Predictors for Rapid Progression of Coronary Calcification: An Optical Coherence Tomography Study

Background The role of coronary calcification in cardiovascular events and plaque stabilization is still being debated, and factors involved in the progression of coronary calcification are not fully understood. This study aimed to identify the predictors for rapid progression of coronary calcification. Methods and Results Patients with serial optical coherence tomography imaging at baseline and at 6 months were selected. Changes in the calcification index and predictors for progression of calcification were studied. Calcification index was defined as the product of the mean calcification arc and calcification length. Rapid progression of calcification was defined as an increase in the calcification index above the median value. Among 187 patients who had serial optical coherence tomography imaging, 235 calcified plaques were identified in 105 patients (56.1%) at baseline. After 6 months, the calcification index increased in 95.3% of calcified plaques from 132.0 to 178.2 (P<0.001). In multivariable analysis, diabetes mellitus (odds ratio [OR], 3.911; P<0.001), chronic kidney disease (OR, 2.432; P=0.037), lipid-rich plaque (OR, 2.698; P=0.034), and macrophages (OR, 6.782; P<0.001) were found to be independent predictors for rapid progression of coronary calcification. Interestingly, rapid progression of calcification was associated with a significant reduction of inflammatory features (thin-cap fibroatheroma; from 21.2% to 11.9%, P=0.003; macrophages; from 74.6% to 61.0%, P=0.001). Conclusions Diabetes mellitus, chronic kidney disease, lipid-rich plaque, and macrophages were independent predictors for rapid progression of coronary calcification. Baseline vascular inflammation and subsequent stabilization may be related to rapid progression of calcification. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01110538.

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.

High-intensity statin therapy yields better outcomes in acute coronary syndrome patients: a meta-analysis involving 26,497 patients

Background

Whether high-intensity statin treatment provides more clinical benefits compared with standard statin regimens in acute coronary syndrome (ACS) patients remains controversial. This meta-analysis aimed to comparatively assess high-intensity and standard statin regimens for efficacy and safety in patients with ACS.

Methods

The PubMed, EMBASE, and Cochrane Library databases were searched for studies assessing high-intensity vs. standard statin regimens for ACS treatment from inception to April 2020. The publication language was limited to English, and 16 randomized controlled trials were finally included in this study, with a total of 26,497 patients.

Results

Compared to the standard statin regimens, the relative ratio (RR) of major adverse cardiovascular events (MACE) in ACS patients treated by high-intensity statin was 0.77 (95%CI, 0.68–0.86; P < 0.00001; prediction interval, 0.56–1.07). In subgroup analysis, high-intensity statin therapy resulted in more clinical benefits regarding MACE compared with standard statin treatment in both Asian (RR = 0.77; 95%CI, 0.61–0.98; P = 0.03) and non-Asian (RR = 0.79; 95%CI, 0.71–0.89; P < 0.0001) patients. Although adverse events were acceptable in patients with ACS administered high-intensity statin therapy, this treatment was associated with a higher rate of adverse events (4.99% vs. 2.98%), including myopathy/myalgia and elevated liver enzymes, as reflected by elevated serum aminotransferase or aminotransferase amounts.

Conclusion

The current findings indicated that high-intensity statin therapy might be beneficial in patients with ACS, and close monitoring for adverse effects should be performed.

Management of non-culprit coronary plaques in patients with acute coronary syndrome

Approximately 50% of patients with ST-segment elevation myocardial infarction (STEMI) have multivessel coronary artery disease, a condition associated with an increased incidence of recurrent ischaemic events and higher mortality. Based on recent evidences, a strategy of staged percutaneous coronary intervention (PCI) of obstructive non-culprit lesions should be considered the gold standard for the management of these patients. However, several issues remain still unresolved. Indeed, what is the optimal timing of staged PCI is not completely defined. Moreover, assessment of intermediate non-culprit lesions represent still a clinical conundrum, as pressure-wire indexes do not seem able to correctly identify those patients in whom deferral is safe. Intracoronary imaging may help to identify untreated non-culprit lesions containing vulnerable plaques that may portend a higher risk of future cardiovascular events. However, there are hitherto no studies demonstrating that preventive PCI of vulnerable plaques or more intensive pharmacological treatment is associated with an improved clinical outcome. In this review, we discuss the recent evolving concepts about management of non-culprit plaques in STEMI patients, proposing a diagnostic and therapeutic algorithm to guide physicians in clinical practice. We also underscore the several knowledge gaps to address in future studies.

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Lipoprotein (a) level is associated with plaque vulnerability in patients with coronary artery disease: An optical coherence tomography study

Background

High lipoprotein (a) [Lp(a)] levels are an independent factor for worse prognosis in patients with coronary artery disease (CAD). However, the association between serum Lp(a) level and coronary plaque vulnerability remains to be determined.

Methods

A total of 255 consecutive patients with CAD who underwent optical coherence tomography imaging of culprit lesions were included. Patients were divided into 2 groups according to their Lp(a) levels (the higher Lp(a) group [≥25 mg/dL], n = 87; or the lower Lp(a) group [<25 mg/dL], n = 168).

Results

The prevalence of thin-cap fibroatheroma (TCFA) was significantly higher in the higher Lp(a) group than in the lower Lp(a) group (23% [n = 20] vs. 11% [n = 19], p = 0.014). Although the prevalence of TCFA was comparable between the 2 groups among patients with a lower LDL cholesterol (LDL-C) level (<100 mg/dL), TCFA was significantly more prevalent in the higher Lp(a) group than in the lower Lp(a) group (39% [14/36] vs. 10% [5/50], p = 0.001) among patients with a higher LDL-C level (≥100 mg/dL).

Conclusions

A higher Lp(a) level was associated with a higher frequency of TCFA, particularly in patients with a higher LDL-C level.

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High Lp(a) (≥25 mg/dL) was observed in 34% of patients requiring PCI.

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Higher Lp(a) was associated with the higher prevalence of thin-cap fibroatheroma.

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High LDL-C enhanced the association between Lp(a) and thin-cap fibroatheroma.

Three-Dimensional Fibrous Cap Structure of Coronary Lipid Plaque - ST-Elevation Myocardial Infarction vs. Stable Angina

BACKGROUND

Fibrous cap thickness (FCT) is one of the key features of coronary vulnerable plaque. FCT is measured at an arbitrary point, determined on visual assessment of 2-D cross-sectional imaging. This method has poor reproducibility. The aim of this study was to compare the 3-D structure of FC in non-culprit lipid plaques between patients with ST-elevation myocardial infarction (STEMI) and with stable angina (SA) on optical coherence tomography.

METHODS AND RESULTS

A total of 54 non-culprit plaques from 23 STEMI and 23 SA patients were evaluated. Thin cap fibroatheroma (TCFA), defined as lipid plaque with FCT <80 µm, was identified using a novel algorithm. The number of TCFA, surface area of each TCFA, and the sum total area of TCFA in the target vessel were measured. Patients with STEMI had a greater median number of TCFA (9, IQR 1-17 vs. 2, IQR 0-5; P=0.002), the largest median single TCFA area (0.40, IQR 0.14-0.69 vs. 0.08, IQR 0.04-0.16 mm2; P<0.001) and median sum total area of TCFA (1.04, IQR 0.41-1.95 vs. 0.24, IQR 0.08-0.48 mm2, P<0.004).

CONCLUSIONS

Patients with STEMI, as compared with those with SA, have greater vulnerability to non-culprit plaque.

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.

Impaired Flow-Mediated Dilation and Severity and Vulnerability of Culprit Plaque in Patients with Coronary Artery Disease

The association between endothelial function, evaluated using flow-mediated dilatation (FMD), and the severity of coronary artery disease remains to be elucidated.A total of 245 consecutive patients with stable angina were prospectively enrolled. FMD was evaluated in the brachial artery before percutaneous coronary intervention. Patients were divided into 2 groups according to the FMD value (lower FMD group [FMD < 2.0], n = 82; higher FMD group [FMD ≥ 2.0], n = 163). The severity of coronary artery disease was evaluated using findings of angiography and optical coherence tomography, and compared between the 2 groups.The prevalence of left main (LM) disease was significantly higher in the lower FMD group than in the higher FMD group (8.5% versus 2.5%, P = 0.046), although the prevalence of multivessel disease was comparable between the groups. Lower FMD was independently associated with a higher prevalence of LM disease (odds ratio, 3.89; 95% confidence interval, 1.12-15.5; P = 0.033). A general linear model with multiple variables revealed that the minimal lumen area (MLA) in the culprit lesion was significantly smaller in patients with lower FMD than in those with higher FMD (regression coefficient b, -0.249 mm²; 95% confidence interval, -0.479--0.018 mm²; P = 0.035). The prevalence ofvulnerable plaque characteristics was comparable between the 2 groups.Patients with lower FMD had a higher incidence of LM disease and a smaller MLA in the culprit lesion. FMD may be a useful, noninvasive indicator for identifying patients with severe coronary artery disease.