Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study

Coronary artery calcification: concepts and clinical applications

Vascular calcification is an important hallmark of atherosclerosis. Coronary artery calcification (CAC) implies the presence of coronary artery disease (CAD), irrespective of risk factors or symptoms, is concomitant with the development of advanced atherosclerosis. Coronary thrombosis is the most common clinical end event leading to acute coronary syndrome (ACS). The least common type of pathology associated with thrombosis is the calcified nodule (CN). It usually occurs in elderly patients with severely calcified and tortuous arteries. The prevalence of calcified nodules in patients with ACS may be underestimated due to the lack of easily recognisable diagnostic methods. In this review, the authors will focus on the classification, clinical significance, pathogenesis, and diagnostic evaluation and treatment of CAC to further explore the clinical significance of CN.

Association Between Body Mass Index and Clinical Outcomes According to Diabetes in Patients Who Underwent Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES

We evaluated the effect of diabetes on the relationship between body mass index (BMI) and clinical outcomes in patients following percutaneous coronary intervention (PCI) with drug-eluting stent implantation.

METHODS

A total of 6,688 patients who underwent PCI were selected from five different registries led by Korean Multicenter Angioplasty Team. They were categorized according to their BMI into the following groups: underweight (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight to obese (≥25.0 kg/m²). Major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of death, nonfatal myocardial infarction, stroke, and target-vessel revascularization, were compared according to the BMI categories (underweight, normal and overweight to obese group) and diabetic status. All subjects completed 1-year follow-up.

RESULTS

Among the 6,688 patients, 2,561 (38%) had diabetes. The underweight group compared to normal weight group had higher 1-year MACCE rate in both non-diabetic (adjusted hazard ratio [HR], 2.24; 95% confidence interval [CI], 1.04-4.84; p=0.039) and diabetic patients (adjusted HR, 2.86; 95% CI, 1.61-5.07; p<0.001). The overweight to obese group had a lower MACCE rate than the normal weight group in diabetic patients (adjusted HR, 0.67 [0.49-0.93]) but not in non-diabetic patients (adjusted HR, 1.06 [0.77-1.46]), with a significant interaction (p-interaction=0.025).

CONCLUSIONS

Between the underweight and normal weight groups, the association between the BMI and clinical outcomes was consistent regardless of the presence of diabetes. However, better outcomes in overweight to obese over normal weight were observed only in diabetic patients. These results suggest that the association between BMI and clinical outcomes may differ according to the diabetic status.

BMI is not independently associated with coronary artery calcification in a large single‐center CT cohort

Objective

Obesity is associated with cardiovascular disease (CVD) and CVD mortality. However, previous reports showed a paradoxical protective effect in patients with known CVD referred as "obesity paradox". Therefore, the aim of the present study was to investigate the association of body mass index (BMI) with coronary artery calcification (CAC) in a large outpatient cardiac CT cohort.

Methods

4.079 patients who underwent cardiac CT between December 2007-May 2014 were analyzed. BMI and clinical risk factors (current smoking, diabetes mellitus type 2, family history, systolic blood pressure, lipid spectrum) were assessed. Missing values were imputed using multiple imputation. CAC extent was categorized as absent (0), mild (>0-100), moderate (>100-400) and severe (>400).

Results

Multivariable multinomial logistic regression analysis, including all risk factors as independent variables, showed no association between BMI and CAC. Using absence of calcification as reference category, the odds ratios per unit increase in BMI were 1.01 for mild; 1.02 for moderate; and 1.00 for severe CAC (p-values ≥0.103).

Conclusions

No statistically significant association was observed between BMI and CAC after adjustment for other risk factors.

Clinical Impact of the Size of Drug-Coated Balloon Therapy on Restenosis Rate in Femoropopliteal Lesions

Purpose:

Although the size of drug-coated balloons (DCBs) is determined according to the vessel diameter during femoropopliteal (FP)-endovascular therapy (EVT), the measurements of the vessel diameter vary among modalities and its definitions. The aim of this study was to reveal whether the DCB size fitting (1) angiographically-measured lumen diameter (Angio-lumen size), (2) intravascular ultrasound (IVUS)-measured lumen diameter (IVUS-lumen size), or (3) IVUS-measured external elastic membrane (EEM) diameter (IVUS-EEM size) would be beneficial in restenosis occurrence.

Materials and Methods:

This retrospective, single-center study included 231 de novo FP lesions in 165 patients with peripheral artery disease treated with IN.PACT Admiral DCB under IVUS evaluation. The reference vessel diameter was evaluated as the lumen or EEM diameter at the healthy site distal to the lesion. We retrospectively determined whether the DCB size was close to (ie, equal to or different by <0.5 mm from) Angio-lumen size, IVUS-lumen size, and IVUS-EEM size. The association of the size of DCB with restenosis risk was investigated.

Results:

The mean lesion length was 13 ± 9 cm and the prevalence of chronic total occlusion was 18%. During a mean follow-up period of 17 ± 9 months, restenosis occurred in 26% of lesions. Lesions treated with a DCB of IVUS-EEM size had a lower 2 year restenosis rate than those treated with a DCB over/under IVUS-EEM size (19.7 ± 5.7% vs 34.5 ± 4.7%, p=0.02 by the log-rank test), while the restenosis rate was not significantly different between DCBs of Angio-lumen size or IVUS-lumen size and those over/under the size (both p>0.05). The multivariate Cox regression analysis revealed that DCBs of IVUS-EEM size were independently associated with a reduced risk of restenosis (adjusted hazard ratio 0.50; 95% confidence interval 0.27–0.95; p=0.03).

Conclusion:

The DCBs of IVUS-EEM size, but not of Angio-lumen size or IVUS-lumen size, were associated with a reduced risk of restenosis after FP-EVT. Determining the DCB size according to IVUS-evaluated EEM diameter would be potentially beneficial in restenosis occurrence.

Risk of coronary heart disease among cancer survivors with different prediagnosis body mass index

Association between body mass index (BMI) and coronary heart disease (CHD) in cancer survivors is not clearly established. This study analyzed the prediagnosis BMI-CHD association by examining 13,500 cancer survivors identified from the National Health Insurance Service-Health Screening Cohort from January 1, 2004 to December 31, 2009 including the patients who were free of cardiovascular disease at enrollment. The Cox proportional hazards model (adjusted for socioeconomic, health behavior, health status, and medical characteristics) was used for calculating hazard ratios (HR) and 95% confidence intervals (95% CI) for CHD in each prediagnosis BMI category among cancer survivors. Compared to cancer survivors with a prediagnosis BMI between 18.5 and 22.9 kg/m2, those with a prediagnosis BMI of 23.0-24.9 kg/m2 and ≥ 25.0 kg/m2 had significantly higher CHD risk (HR = 1.51; 95% CI: 1.13-2.01 and HR = 1.38; 95% CI: 1.04-1.84, respectively). Cancer survivors with a low prediagnosis BMI (< 18.5 kg/m2) also had significantly higher CHD risk (HR = 1.97; 95% CI: 1.20-3.24) compared to those with a BMI of 18.5-22.9 kg/m2. Similar associations were found after stratifying analyses based on first cancer site and sociodemographic and medical characteristic subgroups. Our study suggests that prediagnosis underweight among patients with cancer is a predictor of CHD risk.

Serum soluble Klotho is inversely related to coronary artery calcification assessed by intravascular ultrasound in patients with stable coronary artery disease

BACKGROUND

Although the Klotho gene is recognized as an aging-suppressor gene, the clinical significance of its soluble product, soluble Klotho, in coronary artery disease (CAD) has not been completely determined. The relationship between soluble Klotho and coronary artery calcification (CAC) was investigated in patients with stable CAD.

METHODS

CAC in culprit lesions was analyzed in 75 non-dialysis patients with stable CAD who were scheduled for percutaneous coronary intervention (PCI) following intravascular ultrasound (IVUS). The main outcome measure was the calcium index (CalcIndex), a volumetric IVUS-derived measure of total calcification per culprit lesion. A low CalcIndex was defined as a first-quartile calcium index (<0.042). Patients were divided into two groups according to the median serum Klotho value: low Klotho (n = 37, ≤460 pg/mL) and high Klotho (n = 38, >460 pg/mL).

RESULTS

The CalcIndex was significantly lower in patients with high than with low Klotho. Patients with high Klotho had a significantly higher prevalence of a low CalcIndex than those with low Klotho. The number of angiographic moderate-severe CACs in whole coronary arteries was significantly decreased in patients with high Klotho compared to low Klotho. Serum Klotho levels correlated significantly and inversely with the CalcIndex. This relationship was pronounced in patients with estimated glomerular filtration rate <60 mL/min/1.73 m². Logistic regression analysis showed that high Klotho was associated with a low CalcIndex independent of classical coronary risk factors and markers of mineral metabolism.

CONCLUSIONS

High serum soluble Klotho levels are associated with a low degree of CAC in non-dialysis, stable CAD patients treated by PCI.

Three-dimensional volumetric assessment of coronary artery calcification in patients with stable coronary artery disease by OCT

AIMS

There is a lack of a reliable technique to quantify coronary artery calcification (CAC). Hence, we used optical coherence tomography (OCT) to quantitate three-dimensional CAC volume to examine its association with plaque characteristics.

METHODS AND RESULTS

A total of 250 patients with stable angina undergoing OCT imaging before PCI were included. CAC volume was calculated from every frame of the culprit lesion and divided into tertiles (low, intermediate and high). Quantitative calcium characteristics were assessed in 107 patients who underwent both OCT and IVUS. Increase in CAC volume was associated with reduced lipid volume index, lipid length and number of lipid plaques. Diabetes and LDL cholesterol predicted less coronary calcification whereas age and prior MI predicted increased CAC after adjusting for all clinical factors. Lipid volume index (ρ=-0.001 [-0.003 to -0.00003]; p=0.04) and mean calcium depth (ρ=-0.02 [-0.02 to -0.01]; p=0.000) were inversely related to CAC volume after adjusting for all OCT characteristics, whereas cap thickness increased with increase in CAC volume (ρ=0.01 [0.002-0.03]; p=0.02) only in unadjusted analysis. Regression analysis demonstrated a significant correlation between calcium length (ρ=0.83; p<0.001) and calcium arc (ρ=0.86; p<0.001) measured by IVUS and OCT.

CONCLUSIONS

Target lesions with high CAC volume are characterised by reduced plaque lipid content and calcium closer to the luminal border. Fibrous cap thickness increased with increase in calcium volume.

Impact of Body Mass Index on Vascular Calcification and Pericardial Fat Volume Among Patients with Suspected Coronary Artery Disease

OBJECTIVES

This study aimed to assess the effect of body mass index (BMI) on the relationship between pericardial fat volume (PFV), aortic root calcification (ARC) and coronary artery calcification (CAC) among patients with suspected coronary artery disease (CAD).

METHODS

This cross-sectional study took place between January and December 2014 at the Kufa University Teaching Hospital, Najaf, Iraq. A total of 130 consecutive patients with an intermediate pretest probability of ischaemic heart disease who underwent 64-slice multidetector computed tomography (CT) angiography during the study period were recruited. Of these, 111 were included in the study and divided into groups according to BMI. Imaging markers were measured on CT angiography.

RESULTS

A total of 28 patients were obese, while 42 and 41 were overweight and normal weight, respectively. The median PFV, CAC and ARC was 109 cm(3) (interquartile range [IQR]: 52-176 cm(3)), 0 Agatston score (IQR: 0-52 Agatston score) and 0 Agatston score (IQR: 0-15 Agatston score), respectively, in the normal weight group in comparison to 79 cm(3) (IQR: 43-138 cm(3)), 0 Agatston score (IQR: 0-54 Agatston score) and 0 Agatston score (IQR: 0-0 Agatston score), respectively, in the obese group. Significant correlations were observed between PFV and CAC (r(2) = 0.22; P = 0.002) and ARC and CAC (r(2) = 0.37; P <0.001) in the normal weight group. However, no significant correlations were observed for obese and overweight patients.

CONCLUSION

These findings indicate that BMI may not be an accurate tool for measuring adiposity or assessing subclinical coronary atherosclerosis in patients with suspected CAD.

Effect of Serum Fibrinogen, Total Stent Length, and Type of Acute Coronary Syndrome on 6-Month Major Adverse Cardiovascular Events and Bleeding After Percutaneous Coronary Intervention

This study evaluated the relation between baseline fibrinogen and 6-month major adverse cardiovascular events (MACE) and bleeding after percutaneous coronary intervention (PCI). Three hundred eighty-seven subjects (65.6 ± 16.1 years, 69.5% men, 26.9% acute coronary syndrome [ACS]) who underwent PCI with baseline fibrinogen and platelet reactivity (VerifyNow P2Y12 assay, Accumetrics, San Diego, California) measured were enrolled. Fibrinogen (368.8 ± 144.1 vs 316.8 ± 114.3 mg/dl; p = 0.001), total stent length (TSL; 44.5 ± 25.0 vs 32.2 ± 20.1 mm; p <0.001), and ACS presentation (40.6% vs 23.9%; p = 0.005) were independently associated with 6-month MACE rates (17.8%: myocardial infarction 9.8%, rehospitalization for ACS 3.6%, urgent revascularization 3.6%, stroke 0.5%, and death 0.3%). Measures of platelet reactivity were not associated with 6-month MACE. After multivariate analysis, fibrinogen ≥280 mg/dl (odds ratio [OR] 2.60, 95% CI 1.33 to 5.11, p = 0.005), TSL ≥32 mm (OR 3.21, 95% CI 1.82 to 5.64, p <0.001), and ACS presentation (OR 2.58, 95% CI 1.45 to 4.61, p = 0.001) were associated with higher 6-month MACE. In 271 subjects receiving chronic P2Y12 inhibitor therapy, 6-month Thrombolysis In Myocardial Infarction bleeding after PCI was 7.0%, but no difference in fibrinogen level (338.3 ± 109.7 vs 324.3 ± 113.8 mg/dl, p = 0.60) stratified by Thrombolysis In Myocardial Infarction bleeding was observed. In conclusion, elevated serum fibrinogen, ACS presentation, and longer TSL are independently associated with higher 6-month MACE after PCI, whereas no association with on-thienopyridine platelet reactivity and 6-month MACE was observed. Post-PCI bleeding was not associated with lower fibrinogen level.

Arteriosclerosis and vascular calcification: causes, clinical assessment and therapy

BACKGROUND

Arteriosclerosis is a pathological, structural (media vascular calcification) and physiological (modified vascular smooth vessel cells; increased arterial stiffness) alteration of the vessel wall. Through improved assessment methods (functional and imaging), it has become a well-known phenomenon in recent decades. However, its clinical importance was underestimated until recently.

MATERIALS AND METHODS

Currently available English-speaking data about conditions/diseases associated with arteriosclerosis, its clinical sequels, available diagnostic procedures and therapeutic modalities were reviewed and summarized.

RESULTS

In recent decades, emerging data have brought about a better understanding of causes and consequences of arteriosclerosis and highlight its growing clinical impact.

CONCLUSION

Although arteriosclerosis showed an independent clinical impact on cardiovascular morbidity and mortality, especially in patients with chronic kidney disease/end-stage renal disease (CKD/ESRD) and diabetes mellitus, convincing clinical therapy concepts are not available until now. The establishment of novel therapeutic strategies derived from basic research is strongly needed.

Role of bone mineral density in the inverse relationship between body size and aortic calcification: results from the Baltimore Longitudinal Study of Aging

OBJECTIVE

There is a J-shaped relationship between body mass index (BMI) and cardiovascular outcomes in elderly patients (obesity paradox). Whether low BMI correlates with aortic calcification (AC) and whether this association is accounted for by bone demineralization is uncertain.

METHODS

Presence of AC was evaluated in 687 community-dwelling individuals (49% male, mean age 67 ± 13 years) using CT images of the thoracic, upper and lower abdominal aorta, and scored from 0 to 3 according to number of sites that showed any calcification. Whole-body bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry. Predictors of AC were assessed by logistic regression, and the role of BMD using mediation analysis.

RESULTS

Age and cardiovascular risk factors were positively associated while both BMI (r = -0.11, p < 0.01) and BMD (r = -0.17, p < 0.0001) were negatively associated with AC severity. In multivariate models, lower BMI (OR 0.96, 95%CI 0.92-0.99, p = 0.01), older age, higher systolic blood pressure, use of lipid-lowering drugs and smoking were independent predictors of AC. A nonlinear relationship between BMI and AC was noticed (p = 0.03), with decreased AC severity among overweight participants. After adjusting for BMD, the coefficient relating BMI to AC was reduced by 14% and was no longer significant, whereas BMD remained negatively associated with AC (OR 0.82, 95%CI 0.069-0.96, p = 0.01), with a trend for a stronger relationship in older participants.

CONCLUSION

Low BMI is associated with increased AC, possibly through calcium mobilization from bone, resulting in low BMD. Prevention of weight loss and bone demineralization with aging may help reducing AC.

Vascular imaging in diabetes

Diabetes is a global epidemic affecting individuals of all socioeconomic backgrounds. Despite intensive efforts, morbidity and mortality secondary to the micro- and macrovascular complications remain unacceptably high. As a result, the use of imaging modalities to determine the underlying pathophysiology, early onset of complications, and disease progression has become an integral component of the management of such individuals. Echocardiography, stress echocardiography, and nuclear imaging have been the mainstay of noninvasive cardiovascular imaging tools to detect myocardial ischemia, but newer modalities such as cardiac MRI, cardiac CT, and PET imaging provide incremental information not available with standard imaging. While vascular imaging to detect cerebrovascular and peripheral arterial disease non-invasively has traditionally used ultrasound, CT- and MRI-based techniques are increasingly being employed. In this review, we will provide an outline of recent studies utilizing non-invasive imaging techniques to assist in disease diagnosis as well as monitoring disease progression. In addition, we will review the evidence for newer modalities such as MR spectroscopy, 3D intravascular ultrasound, and optical coherence tomography that provide exquisite detail of metabolic function and coronary anatomy not available with standard imaging, but that have not yet become mainstream.