Age-related effects of smoking on culprit lesion plaque vulnerability as assessed by grayscale and virtual histology–intravascular ultrasound

Insulin resistance is associated with high-risk coronary artery plaque composition in asymptomatic men between 65 and 75 years and no diabetes: A DANCAVAS cross-sectional sub-study

BACKGROUND AND AIMS

Insulin resistance (IR) and pre-diabetes are associated with an increased risk of cardiovascular disease (CVD). We aimed to investigate vulnerable plaque composition in relation to IR and pre-diabetes in asymptomatic non-diabetic men.

METHODS

All participants underwent a contrast-enhanced coronary computed tomography angiography (CCTA) to evaluate coronary artery plaque burden and plaque composition (necrotic core, dense calcium, fibrotic and fibrous-fatty volume). Homeostasis model assessment of IR (HOMA-IR) was used, and participants were stratified into tertiles. Participants underwent a standard oral glucose tolerance test (OGTT) and were categorized into 2 groups (normal glucose tolerance (NGT) or pre-diabetes). A multivariable linear regression model was used to evaluate the association between vulnerable plaque composition and IR or glycemic group.

RESULTS

Four-hundred-and-fifty non-diabetic men without known CAD were included. The mean age was 70 ± 3 years. Participants in the higher HOMA-IR tertile (H-IR) had higher median necrotic plaque volume compared to the lower HOMA-IR tertile (L-IR) (18.2 vs. 11.0 mm3, p = 0.02). H-IR tertile (β 0.37 [95% CI 0.10-0.65], p = 0.008), pack-years (β 0.07 [95% CI 0.007-0.14], p = 0.03) and total atheroma volume (TAV) (β 0.47 [95% CI 0.36-0.57], p < 0.001) remained associated with necrotic plaque volume in the multivariable linear regression model.

CONCLUSIONS

IR was associated with necrotic plaque volume in asymptomatic men without diabetes. Thus, even in asymptomatic men without diabetes, IR seems to have an incremental effect on necrotic plaque volume and vulnerable plaque composition.

Impact of smoking on all-cause mortality and cardiovascular events in patients after coronary revascularization with a percutaneous coronary intervention or coronary artery bypass graft: a systematic review and meta-analysis

Although cigarette smoking is an independent risk factor for cardiovascular disease, inconsistent results have been published in the literature on its impacts on the cardiovascular health of patients after coronary revascularization with a percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). We performed a comprehensive electronic database search through July 2018. Studies reporting the risk estimates of all-cause mortality and cardiovascular outcomes in patients after coronary revascularization with PCI or CABG on the basis of smoking status were selected. Multivariate-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were pooled using random-effects models with inverse variance weighting. Data from 37 records including 126 901 participants were finally collected. Overall, the pooled RR (95% CI) associated with cigarette smoking was 1.26 (95% CI: 1.09-1.47) for all-cause mortality, 1.08 (95% CI: 0.92-1.28) for major adverse cardiovascular events, 0.96 (95% CI: 0.69-1.35) for cardiovascular mortality and 1.15 (95% CI: 0.81-1.64) for myocardial infarction. The increased risk of all-cause mortality was also observed in former smokers compared with those who had never smoked (RR: 1.19; 95% CI: 1.03-1.38). Furthermore, the negative effects of cigarette smoking on all-cause mortality were also observed in most subgroups. Cigarette smoking has been shown to increase the likelihood of all-cause mortality in patients after coronary revascularization with PCI or CABG. Smoking cessation is essential for PCI or CABG patients to manage their coronary artery disease.

Attenuated Superoxide Dismutase 2 Activity Induces Atherosclerotic Plaque Instability During Aging in Hyperlipidemic Mice

BACKGROUND

Atherosclerosis progression during aging culminates in the development of vulnerable plaques, which may increase the risk of cardiovascular events. Increased generation and/or decreased scavenging of reactive oxygen species in the vascular wall are major contributors to atherogenesis. We previously showed that superoxide dismutase 2 deficiency increased vascular oxidative stress and reduced aortic compliance in aged wild-type mice and that young Apoe-/-/Sod2+/- had increased mitochondrial DNA damage and atherosclerosis versus young Apoe-/- mice. Here we investigated the effects of superoxide dismutase 2 deficiency on atherosclerosis progression and plaque morphology in middle-aged Apoe-/- mice.

METHODS AND RESULTS

Compared with Apoe-/-, middle-aged Apoe-/-/Sod2+/- mice had increased vascular wall reactive oxygen species (P<0.05) and higher atherosclerotic lesion area (P<0.001). The atherosclerotic plaques in middle-aged Apoe-/-/Sod2+/- mice had an increased necrotic core with higher inflammatory cell infiltration, a thinned fibrous cap with depleted smooth muscle content, and intraplaque hemorrhage. In addition, the plaque shoulder area had higher levels of calpain-2, caspase-3, and matrix metalloproteinase-2 in intimal smooth muscle cells and depleted fibrous cap collagen. Targeting mitochondrial reactive oxygen species with MitoTEMPO attenuated features of atherosclerotic plaque vulnerability in middle-aged Apoe-/-/Sod2+/- mice by lowering expression of calpain-2, caspase-3, and matrix metalloproteinase-2 and decreasing smooth muscle cell apoptosis and matrix degradation.

CONCLUSIONS

Enhanced mitochondrial oxidative stress under hyperlipidemic conditions in aging induces plaque instability, in part by increasing smooth muscle cell apoptosis, necrotic core expansion, and matrix degradation. Targeting mitochondrial reactive oxygen species or its effectors may be a viable therapeutic strategy to prevent aging-associated and oxidative stress-related atherosclerosis complications.

Does calcium burden impact culprit lesion morphology and clinical results? An ADAPT-DES IVUS substudy

BACKGROUND

Increasing coronary lesion calcification is thought to be associated with adverse percutaneous coronary intervention (PCI) and clinical outcomes. We investigated the effects of calcium burden on culprit lesion morphology and clinical events after intravascular ultrasound (IVUS)-guided PCI in the ADAPT-DES study.

METHODS

ADAPT-DES was a prospective, multicenter registry of 8582 consecutive patients undergoing successful PCI using DES. A pre-specified virtual histology (VH)-IVUS substudy of 638 culprit lesions (638 patients) had both pre- and post-PCI VH-IVUS. We divided lesions into tertiles according to pre-PCI percent dense calcium volume (DCV%=dense calcium/plaque volume×100).

RESULTS

Compared with low and intermediate DCV% tertiles, patients in the high DCV% tertile had the largest arc of superficial calcium, highest percentage of necrotic core volume, and smallest remodeling index; they were also more likely to have advanced lesion morphology such as attenuated plaque and VH thin-cap fibroatheromas. In the high DCV% tertile IVUS guidance was associated with a minimum stent area that was smaller than tertiles with less calcium (p=0.01), but acceptable range, and similar stent expansion (73.8±16.8% vs. 74.0±19.2% vs. 72.4±17.3%, p=0.62) after more frequent use of rotational atherectomy and higher maximum inflation pressure. There was no significant association between pre-PCI DCV% and 2-year target lesion revascularization or major adverse cardiac events (cardiac death, myocardial infarction, or stent thrombosis).

CONCLUSIONS

Increasing coronary artery calcification burden was associated with more advanced, complex VH-IVUS lesion morphology, but not with adverse clinical outcomes, perhaps due to more aggressive PCI techniques that optimized stent expansion.

Age and cigarette smoking modulate the relationship between pulmonary function and arterial stiffness in heart failure patients

The aim of this study was to assess the relationship between arterial stiffness and pulmonary function in chronic heart failure (CHF).Outpatients previously diagnosed as CHF were enrolled between April 2008 and March 2010, and submitted to arterial stiffness measurement and lung function assessment. Spirometry was performed by measuring forced vital capacity (FVC), the fraction of predicted FVC, forced expiratory volume in 1 second (FEV1), the percentage of predicted FEV1 in 1 second, FEV1 to FVC ratio, and the percentage of predicted FEV1/FVC. Cardio-ankle vascular index (CAVI) was considered for the estimation of arterial stiffness.The 354 patients assessed included 315 nonsmokers, and were 68.2 ± 7.2 years' old. Unadjusted correlation analyses demonstrated CAVI was positively related to age (r = 0.3664, P < 0.0001), and negatively related to body mass index (BMI, r = -0.2040, P = 0.0001), E/A ratio (r = -0.1759, P = 0.0010), and FEV1 (r = -0.2987, P < 0.0001). Stepwise multivariate regression analyses showed age (r = 0.2391, P < 0.0001), BMI (r = -0.2139, P < 0.0001), smoking (r = 0.1211, P = 0.0130), E/A ratio (r = -0.1082, P = 0.0386), and FEV1 (r = -0.2550, P < 0.0001) were independent determinants of CAVI. In addition, there is a significant interaction between CAVI and forced expiratory volume in 1 second (FEV1) in relation to age (Pint < 0.0001) and smoking (Pint = 0.0001). Meanwhile, pulmonary function was not associated with BMI or E/A ratio.These findings demonstrated that reduced pulmonary function is associated with the increased CAVI, and had an interactive effect with age and smoking on CAVI in patients with CHF.

Evolution of nonculprit coronary atherosclerotic plaques assessed by serial virtual histology intravascular ultrasound in patients with ST-segment elevation myocardial infarction and chronic total occlusion

OBJECTIVE

The pathophysiology and natural course of coronary nonculprit plaques remain unclear. We investigated whether the short-term natural course of nonculprit plaques differs between ST-segment elevation myocardial infarction (STEMI) and chronic total occlusion (CTO) patients.

METHODS

We performed serial virtual histology intravascular ultrasound on nonculprit plaques in 26 STEMI and 11 CTO lesions at baseline and the 6-month follow-up.

RESULTS

At baseline, more lesions in the STEMI group were virtual histology intravascular ultrasound-derived thin-cap fibroatheromas (TCFA; 76.9 vs. 18.1%, P=0.002). During the follow-up period, the plaque composition changed dynamically in the STEMI group (fibrofatty: 9.8±1.9 to 17.3±2.9%, P=0.030; dense calcium: 12.7±1.8 to 8.1±1.7%, P=0.026; necrotic core: 21.1±1.8 to 15.4±2.2%, P=0.052), with a consistent plaque size. In the CTO group, the plaque composition and plaque size remained consistent without a significant change. Also, more lesions in the STEMI group remained as or progressed to TCFA, compared with the CTO group (67 vs. 11%, P=0.089). Factors associated with a persistent TCFA or with a new development of TCFA were a large necrotic core volume index and the diagnosis of STEMI, whereas new statin usage was a protective factor.

CONCLUSION

Nonculprit lesions in STEMI patients were more unstable at the baseline compared with those in CTO patients. During follow-up, nonculprit lesions in STEMI and CTO patients showed a distinct pattern of change; the former were stabilized in plaque composition, whereas the latter remained consistent. The diagnosis of STEMI and a large necrotic core volume were predictors of evolution to a TCFA, and new statin usage was a protective factor.