Relationship between cardiovascular risk factors and biomarkers with necrotic core and atheroma size: a serial intravascular ultrasound radiofrequency data analysis

CT-derived fractional flow reserve for prediction of major adverse cardiovascular events in diabetic patients

OBJECTIVES

To investigate the prognostic value of computed tomography fractional flow reserve (CT-FFR) in patients with diabetes and to establish a risk stratification model for major adverse cardiac event (MACE).

METHODS

Diabetic patients with intermediate pre-test probability of coronary artery disease were prospectively enrolled. All patients were referred for coronary computed tomography angiography and followed up for at least 2 years. In the training cohort comprising of 957 patients, two models were developed: model1 with the inclusion of clinical and conventional imaging parameters, model2 incorporating the above parameters + CT-FFR. An internal validation cohort comprising 411 patients and an independent external test cohort of 429 patients were used to validate the proposed models.

RESULTS

1797 patients (mean age: 61.0 ± 7.0 years, 1031 males) were finally included in the present study. MACE occurred in 7.18% (129/1797) of the current cohort during follow- up. Multivariate Cox regression analysis revealed that CT-FFR ≤ 0.80 (hazard ratio [HR] = 4.534, p < 0.001), HbA1c (HR = 1.142, p = 0.015) and low attenuation plaque (LAP) (HR = 3.973, p = 0.041) were the independent predictors for MACE. In the training cohort, the Log-likelihood test showed statistical significance between model1 and model2 (p < 0.001). The C-index of model2 was significantly larger than that of model1 (C-index = 0.82 [0.77-0.87] vs. 0.80 [0.75-0.85], p = 0.021). Similar findings were found in internal validation and external test cohorts.

CONCLUSION

CT-FFR was a strong independent predictor for MACE in diabetic cohort. The model incorporating CT-FFR, LAP and HbA1c yielded excellent performance in predicting MACE.

Pathophysiology of Atherosclerosis

Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.

HbA1c, Coronary atheroma progression and cardiovascular outcomes

Background and aims

We tested the hypothesis that on-treatment HbA1c levels independently associate with coronary atheroma progression and major adverse cardiovascular events (MACE: death, myocardial infarction, cerebrovascular accident, coronary revascularization, or hospitalization for unstable angina) rates.

Methods

We performed a post-hoc pooled analysis of data from seven prospective, randomized trials involving serial coronary intravascular ultrasonography (IVUS). The percent atheroma volume (PAV) was calculated as the proportion of the entire vessel wall occupied by atherosclerotic plaque. Using multivariable mixed modeling, we determined the association of on-treatment HbA1c with annualized change in PAV. Cox proportional hazard models were used to assess the association of HbA1c with incidence of MACE.

Results

Among 3,312 patients (mean age 58.6±9years, 28.4%women) average on-treatment HbA1c was 6.2±1.1%. Overall, there was no net significant annualized change in PAV (0.12±0.19%, p = 0.52). In a fully adjusted multivariable analysis (following adjustment of age, sex, body mass index, systolic blood pressure, smoking, low- and high-density lipoprotein cholesterol, triglyceride levels, peripheral vascular disease, trial, region, and baseline PAV), higher on-treatment HbA1c levels were independently associated with annualized changes in PAV [beta-estimate (95% confidence interval): 0.13(0.08, 0.19), p < 0.001]. On-treatment HbA1c levels were independently associated with MACE [hazard ratio (95% confidence interval): 1.13(1.04, 1.23), p = 0.005].

Conclusions

Independent of achieved cardiovascular risk factor control, greater HbA1c levels significantly associate with coronary atheroma progression rates and clinical outcomes. These results support the notion of a direct, specific effect of glycemic control upon coronary atheroma and atherosclerotic events, supporting the rationale of therapies designed to directly modulate it.

NaF-PET/CT global assessment in detecting and quantifying subclinical cardiac atherosclerosis and its association with blood pressure in non-dyslipidemic individuals

BACKGROUND

We used ¹⁸F-sodium fluoride (NaF) to assess early atherosclerosis in the global heart in asymptomatic individuals with a coronary calcium score of zero and without a formal diagnosis of hypertension. We hypothesized that these individuals might present with subclinical atherosclerosis that correlates with systolic, diastolic and mean arterial pressure (SBP, DBP, and MAP).

METHODS

We identified 20 asymptomatic individuals (41.6 ± 13.8 years, 8 females) from the CAMONA trial with C-reactive protein ≥3 mg/L, no smoking history, diabetes (fasting blood glucose <126 mg/dl) and dyslipidemia per the Adult Treatment Panel III Guidelines: untreated LDL <160 mg/dL, total cholesterol <240 mg/dL, HDL >40 mg/dL. All underwent PET/CT imaging 90 minutes after NaF injection (2.2 Mbq/Kg). The global cardiac average SUVmean (aSUVmean) was calculated for each individual. Correlation coefficients and linear regression models were employed for statistical analysis.

RESULTS

Significant positive correlation was revealed between global cardiac NaF uptake and all blood pressures: SBP (r=0.44, P=0.05), DBP (r=0.64, P=0.002), and MAP (r=0.59, P=0.007). After adjusting for age and gender, DBP and MAP were independent predictors of higher global cardiac NaF uptake.

CONCLUSION

NaF-PET/CT for detecting and quantifying subclinical atherosclerosis in asymptomatic individuals revealed that cardiac NaF uptake correlated independently with DBP and MAP.

Pro-inflammatory Cytokines in Acute Coronary Syndromes

BACKGROUND

Over the last decades, the role of inflammation and immune system activation in the initiation and progression of coronary artery disease (CAD) has been established.

OBJECTIVES

The study aimed to present the interplay between cytokines and their actions preceding and shortly after ACS.

METHODS

We searched in a systemic manner the most relevant articles to the topic of inflammation, cytokines, vulnerable plaque and myocardial infarction in MEDLINE, COCHRANE and EMBASE databases.

RESULTS

Different classes of cytokines (intereleukin [IL]-1 family, Tumor necrosis factor-alpha (TNF-α) family, chemokines, adipokines, interferons) are implicated in the entire process leading to destabilization of the atherosclerotic plaque, and consequently, to the incidence of myocardial infarction. Especially IL-1 and TNF-α family are involved in inflammatory cell accumulation, vulnerable plaque formation, platelet aggregation, cardiomyocyte apoptosis and adverse remodeling following the myocardial infarction. Several cytokines such as IL-6, adiponectin, interferon-γ, appear with significant prognostic value in ACS patients. Thus, research interest focuses on the modulation of inflammation in ACS to improve clinical outcomes.

CONCLUSION

Understanding the unique characteristics that accompany each cytokine-cytokine receptor interaction could illuminate the signaling pathways involved in plaque destabilization and indicate future treatment strategies to improve cardiovascular prognosis in ACS patients.

Preoperative hypertension is associated with atherosclerotic intraplaque hemorrhage in patients undergoing carotid endarterectomy

BACKGROUND AND AIMS

Both hypertension and atherosclerotic plaque characteristics such as intraplaque hemorrhage (IPH) are associated with cardiovascular events (CVE). It is unknown if hypertension is associated with IPH. Therefore, we studied if hypertension is associated with unstable atherosclerotic plaque characteristics in patients undergoing carotid endarterectomy (CEA).

METHODS

Prospectively collected data of CEA-patients (2002-2014) were retrospectively analyzed. Blood pressure (BP) was the mean of 3 preoperative measurements. Preoperative hypertension was defined as systolic BP ≥ 160 mmHg. Post-CEA, carotid atherosclerotic plaques were analyzed for the presence of calcifications, collagen, smooth muscle cells, macrophages, lipid core, IPH and microvessel density. Associations between BP (systolic and diastolic), patient characteristics and carotid plaque characteristics were assessed with univariate and multivariate analyses with correction for potential confounders. Results were replicated in a cohort of patients that underwent iliofemoral endarterectomy.

RESULTS

Within CEA-patients (n = 1684), 708 (42%) had preoperative hypertension. Increased systolic BP was associated with the presence of plaque calcifications (adjusted OR1.11 [95% CI 1.01-1.22], p = 0.03), macrophages (adjusted OR1.12 [1.04-1.21], p < 0.01), lipid core >10% of plaque area (adjusted OR1.15 [1.05-1.25], p < 0.01), IPH (adjusted OR1.12 [1.03-1.21], p = 0.01) and microvessels (adjusted beta 0.04 [0.00-0.08], p = 0.03). Increased diastolic BP was associated with macrophages (adjusted OR1.36 [1.17-1.58], p < 0.01), lipid core (adjusted OR1.29 [1.10-1.53], p < 0.01) and IPH (adjusted OR1.25 [1.07-1.46], p < 0.01) but not with microvessels nor plaque calcifications. Replication in an iliofemoral-cohort (n = 657) showed that increased diastolic BP was associated with the presence of macrophages (adjusted OR1.78 [1.13-2.91], p = 0.01), lipid core (adjusted OR1.45 [1.06-1.98], p = 0.02) and IPH (adjusted OR1.48 [1.14-1.93], p < 0.01).

CONCLUSIONS

Preoperative hypertension in severely atherosclerotic patients is associated with the presence of carotid plaque macrophages, lipid core and IPH. IPH, as a plaque marker for CVE, is associated with increased systolic and diastolic BP in both the CEA and iliofemoral population.

IgM anti-malondialdehyde low density lipoprotein antibody levels indicate coronary heart disease and necrotic core characteristics in the Nordic Diltiazem (NORDIL) study and the Integrated Imaging and Biomarker Study 3 (IBIS-3)

Background

Certain immunoglobulins (Ig) are proposed to have protective functions in atherosclerosis.

Objectives

We tested whether serum levels of IgG and IgM autoantibodies against malondialdehyde low density lipoprotein (MDA-LDL) are associated with clinical coronary heart disease (CHD) and unfavorable plaque characteristics.

Methods

NORDIL was a prospective study investigating adverse cardiovascular outcomes in hypertensive patients. IBIS-3 analyzed lesions in a non-culprit coronary artery with <50% stenosis using radiofrequency intravascular ultrasound (RF-IVUS) and near-infrared spectroscopy (NIRS). Imaging was repeated after a median of 386?days on rosuvastatin. Associations of antibodies with incident CHD and imaging parameters were assessed in the two sub-studies respectively.

Findings

From 10,881 NORDIL patients, 87 had serum sampled at baseline and developed CHD over 4.5 years, matched to 227 controls. Higher titers of IgM anti-MDA-LDL had a protective effect on adverse outcomes, with odds ratio 0.29 (0.11, 0.76; p=0.012; p=0.016 for trend). Therefore, the effect was explored at the lesional level in IBIS-3. 143 patients had blood samples and RF-IVUS measurements available, and NIRS was performed in 90 of these. At baseline, IgM anti-MDA-LDL levels had a strong independent inverse relationship with lesional necrotic core volume (p=0.027) and percentage of plaque occupied by necrotic core (p=0.011), as well as lipid core burden index (p=0.024) in the worst 4 mm segment.

Interpretation

Our study supports the hypothesis that lower circulating levels of IgM anti-MDA-LDL are associated with clinical CHD development, and for the first time relates these findings to atherosclerotic plaque characteristics that are linked to vulnerability.

Diastolic blood pressure predicts coronary plaque volume in patients with coronary artery disease

BACKGROUND AND AIMS

Hypertension is associated with increased clinical and subclinical coronary artery disease (CAD); however, the relationship between blood pressure and coronary plaque volume is unclear. We examined the effect of systolic blood pressure (SBP) and diastolic blood pressure (DBP) on coronary artery plaque volume.

METHODS

285 subjects with stable CAD on statin therapy underwent coronary computed tomographic angiography to measure volume of fatty, fibrous, noncalcified, calcified and total coronary plaque.

RESULTS

Mean (SD) age was 63.1 (7.7); mean (SD) LDL-C, 78.7 mg/dL (28.5). Compared to the highest DBP tertile (>76 mmHg), those in the lowest DBP tertile (≤68 mmHg) had lower volumes of fatty: 10.0 vs. 7.7 mm³/mm, (p trend = 0.042), fibrous: 19.6 vs. 13.8 mm³/mm (p trend = 0.011), non-calcified: 29.7 vs. 22.5 mm³/mm (p trend = 0.017) and total plaque: 37.8 vs. 25.1 mm³/mm (p trend = 0.010) whereas there was no relationship with SBP tertiles. Similarly, when examined as a continuous variable, higher DBP was a significant independent predictor of higher plaque volume after multivariate adjustment: for every 1 mmHg increase in DBP, fibrous plaque increased 0.128 mm³/mm (p = 0.022), noncalcified plaque increased 0.176 mm³/mm (p = 0.045), calcified plaque increased 0.096 mm³/mm (p = 0.001) and total plaque increased 0.249 mm³/mm (p = 0.019) whereas SBP ranging from 95 to 154 mmHg did not predict plaque volume.

CONCLUSIONS

Level of DBP predicts coronary plaque with a DBP tertile ≤68 mmHg associated with the least amount of coronary plaque in subjects with LDL-C < 80 mg/dL.

Impact of the Everolimus-eluting Bioresorbable Scaffold in Coronary Atherosclerosis

INTRODUCTION AND OBJECTIVES

The Absorb bioresorbable vascular scaffold has been shown to decrease total plaque areas in the treated segment. However, it is unknown whether plaque size is modified in scaffolded segments only or whether the modification extends to other coronary segments.

METHODS

Absorb Cohort A is a single-arm, prospective study, with safety and imaging endpoints, in which 30 patients underwent percutaneous coronary intervention with the first generation Absorb bioresorbable vascular scaffold. Noninvasive multislice computed tomography imaging was performed in 18 patients at 18 months and 5 years of follow-up. The present study was an intrapatient comparison of matched segments (normalized by the segment length) of the scaffolded region with nonintervened segments for lumen volume, vessel volume, plaque volume, plaque burden, and percent change in plaque atheroma volume.

RESULTS

All 18 scaffolded segments could be analyzed. In the nonintervened segments, 1 of 72 segments had a motion artifact and was excluded. Serial comparison showed that the scaffolded segments showed no significant change in the mean plaque burden, total atheroma volume, total lumen volume, or vessel volume between 18 months and 5 years. Conversely, the untreated segments showed a significant increase in plaque burden (2.7 ± 6.5%; P < .01) and normalized plaque volumes (8.0 ± 22.8mm(3); P < .01). This resulted in a significant difference in plaque burden between scaffolded and nonintervened segments (P = .03).

CONCLUSIONS

In this small series, the Absorb bioresorbable vascular scaffold showed the potential to provide an additional benefit to pharmacological therapy in locally reducing progression of percent plaque burden. These findings need to be confirmed in larger studies.

The association of hemoglobin A1c and high risk plaque and plaque extent assessed by coronary computed tomography angiography

The objective of this study was to investigate the relationship of Hemoglobin A1c (HbA1c) and plaque characteristics including high risk plaque and plaque extent. We retrospectively examined 1079 consecutive coronary computed tomography (CT) angiography scans and the HbA1c results. We divided the patients into four groups by the HbA1c status: non-diabetic, ≤6.0; borderline, 6.1-6.4; diabetic low, 6.5-7.1; diabetic high, >7.1. We determined segment involvement score >4 as extensive disease. High risk plaque was defined as two feature positive (FP) plaque which consists of positive remodeling (remodeling index >1.1) and low attenuation (<30 HU). Univariate and multivariate analysis including conventional cardiovascular risk factors, symptoms and medication was performed. Univariate analysis showed that diabetic patients as well as borderline patients were significantly related with 2FP plaque and extensive disease. Although the relationship of borderline patients and 2FP plaque was marginal in multivariate analysis [odds ratio (OR) 1.53, 95% confidence interval (CI) 0.95-2.40, p = 0.07], the elevation of HbA1c was strongly associated with 2FP plaque (diabetic low, OR 2.19, 95% CI 1.37-3.45, p < 0.005; diabetic high, OR 4.14, 95% CI 2.57-6.67, p < 0.0005). The association of HbA1c elevation and extensive disease was quite similar between borderline and diabetic patients (borderline, OR 1.96, 95% CI 1.29-2.95, p < 0.005; diabetic low, OR 1.94, 95% CI 1.25-3.01, p < 0.005; diabetic high, OR 2.19, 95% CI 1.39-3.43, p < 0.005). Patients with elevated HbA1c of >6.0 are potentially at risk for future cardiovascular events due to increased high risk plaque and extensive disease, even below the diabetic level of 6.5. Coronary CT could be used for risk stratification of these patients.

European Society of Cardiology (ESC) congress report from Barcelona 2014

The Annual Congress of the European Society of Cardiology (ESC) was held in Barcelona from 30th August to 3rd September 2014. More than 30,300 attendees from around the world shared the latest original research, including 27 clinical Hot Line studies, 12 basic science Hot Lines, 15 clinical trial updates, 19 registry studies, and 4,597 abstracts. Many important issues were presented, including novel treatment strategies for heart failure, acute coronary syndrome, interventional treatment for structural heart disease, renal denervation, novel anticoagulant therapies, atrial fibrillation and so on. In addition, 5 new ESC clinical practice guidelines (ie, myocardial revascularization, non-cardiac surgery, acute pulmonary embolism, hypertrophic cardiomyopathy, and aortic disease) were launched. It should be noted that Japan has recently been ranked in the top position in terms of the number of abstract submissions. Based on these activities, the ESC Congress has been recognized as the dominant scientific and educational forum for healthcare professionals in cardiology. We report the highlights and several key presentations of the ESC Congress 2014. The scientific activities and growing contributions of Japanese cardiologists or cardiovascular surgeons enhance the favorable relationship between the ESC and the Japanese Circulation Society.

Differential impact of five coronary devices on plaque size: insights from the ABSORB and SPIRIT trials

BACKGROUND

Coronary plaque size modification, by either local (device) or systemic treatments, has been the target for many years.

METHODS

From ABSORB Cohort A (Absorb BVS 1.0), ABSORB Cohort B (Absorb BVS 1.1), SPIRIT FIRST (Multi-Link Vision vs. Xience V) & SPIRIT II (Xience V vs. Taxus), we calculated the total plaque area (vessel minus lumen area - thus it comprises both compartments - the plaque behind struts and the neointima.) changes by IVUS.

RESULTS

A total of 313 patients were included. Comparison-at-6-month follow-up: All devices induced an increase in the total plaque area. The largest increase occurred with Vision and Taxus stents as compared to other devices [Absorb BVS (1.0 and 1.1) and Xience V], (p=0.0002). Comparison-at-2-year follow-up: Absorb BVS 1.1 had a larger increase from post procedure in total plaque compared to Absorb BVS 1.0, Xience V and Taxus (p=0.0499). However, in Absorb BVS 1.1 total plaque showed a reduction of 2.2% from 1 to 3 years. Specifically, the total plaque in the sequential cohorts of Absorb BVS 1.1 increased 16.2% from baseline to 2 years (Cohort B1) while at 3 years this increase is only 5% compared to baseline (Cohort B2).

CONCLUSIONS

Local devices affect coronary plaque size differently and it depends on the platform (metallic vs. polymeric) and on whether it is a bare - or drug eluting stent. Coronary scaffolds appear to be a promising alternative to metallic stents since they allow plaque regression at long-term follow-up.

Virtual histology assessment of coronary atheroma influences treatment strategy in the young acute coronary syndrome patient

A 43-year-old woman having significant risk factors for ischaemic heart disease was admitted with an acute coronary syndrome (ACS). Coronary angiography revealed a non-flow limiting lesion in her right coronary artery with the rest of her arteries unremarkable. Risk stratification of the culprit lesion in the right coronary artery through intravascular ultrasound virtual histology demonstrated that the rupture plaque had less than 5% necrotic core with low vulnerability indices. This important finding suggested that the re-rupture risk was low so aggressive pharmacological treatment that can influence the plaque characteristics was instigated in preference to mechanical plaque sealing with a coronary stent. At a year of follow-up the patient was well and had no further events.

Targeting inflammation: impact on atherothrombosis

Atherothrombosis is a worldwide epidemic accounting for an unacceptable toll of deaths and disabilities. Its pathophysiology is complex and hardly referable to a specific mechanism; however, in the last 20 years, a growing amount of evidence has demonstrated that inflammatory processes play a major role from the very beginning to the ultimate complication of atherothrombosis. These evidences are addressing a growing interest toward anti-inflammatory agents as preventive or curative treatments of atherothrombosis. At present, accumulated data are not conclusive, but strong evidence exists in favor of an anti-inflammatory positive effect for several drugs as statins or renin-angiotensin inhibitors. More conclusive data are expected from ongoing trials directly exploring the role of specific cytokines antagonists.