Association of Aortic Atherosclerosis and Renal Dysfunction

Aortic plaque burden predicts vascular events in patients with cardiovascular disease: The EAST-NOGA study

BACKGROUND

Non-obstructive general angioscopy (NOGA) can be used to diagnose aortic atherosclerotic plaques. We examine the association between the number of aortic plaques detected by NOGA and the risk of subsequent cardiovascular events.

METHODS

The Evaluation of AtheroScleroTic and rupture events by Non-Obstructive General Angioscopy (EAST-NOGA) was a prospective cohort study of patients with suspected coronary artery disease who underwent NOGA.

RESULTS

Of the 577 patients who underwent NOGA, 532 (92%) completed the follow-up (median follow-up: 13 months, interquartile range: 12-16). The median number of plaques per person was 6 (interquartile range: 3-12), and 567 (98%) had at least one aortic plaque. During the 13-month follow-up, 38 (7.1%) patients had a primary composite endpoint [including cardiovascular death, myocardial infarction, stroke, peripheral artery disease (PAD), or worsening renal function], which was significantly associated with chronic kidney disease, a history of PAD, a lower hemoglobin level, and large numbers of aortic plaques [11 (5-17) vs. 6 (2-11), p = 0.003]. A receiver operating characteristic curve analysis for the number of aortic plaques predicting composite endpoints revealed that the cut-off value of aortic plaques was 12. After multivariate adjustment, the presence of ≥12 aortic plaques remained a significant predictor for composite endpoint events (hazard ratio 2.53, 95% confidence interval 1.26-5.04, p = 0.010).

CONCLUSIONS

The number of aortic plaques detected by NOGA may predict subsequent clinical events.

High Wall Shear Stress Is Related to Atherosclerotic Plaque Rupture in the Aortic Arch of Patients with Cardiovascular Disease: A Study with Computational Fluid Dynamics Model and Non-Obstructive General Angioscopy

Aims: Wall shear stress (WSS) has been considered a major determinant of aortic atherosclerosis. Recently, non-obstructive general angioscopy (NOGA) was developed to visualize various atherosclerotic pathologies, including in vivo ruptured plaque (RP) in the aorta. However, the relationship between aortic RP and WSS distribution within the aortic wall is unclear. This study aimed to investigate the relationship between aortic NOGA-derived RP and the stereographic distribution of WSS by computational fluid dynamics (CFD) modeling using three-dimensional computed tomography (3D-CT) angiography.

Methods: We investigated 45 consecutive patients who underwent 3D-CT before coronary angiography and NOGA during coronary angiography. WSS in the aortic arch was measured by CFD analysis based on the finite element method using uniform inlet and outlet flow conditions. Aortic RP was detected by NOGA.

Results: Patients with a distinct RP showed a significantly higher maximum WSS value in the aortic arch than those without aortic RP (56.2±30.6 Pa vs 36.2±19.8 Pa, p =0.017), no significant difference was noted in the mean WSS between those with and without aortic RP. In a multivariate logistic regression analysis, the presence of a maximum WSS value more than a specific value was a significant predictor of aortic RP (odds ratio 7.21, 95% confidence interval 1.78-37.1, p =0.005).

Conclusions: Aortic RP detected by NOGA was strongly associated with a higher maximum WSS in the aortic arch derived by CFD using 3D-CT. The maximum WSS value may have an important role in the underlying mechanism of not only aortic atherosclerosis, but also aortic RP.

Atherosclerosis burden of the aortic valve and aorta and risk of acute kidney injury after transcatheter aortic valve implantation

BACKGROUND

Atheroembolic renal disease, due to dislodgement of cholesterol crystals during maneuvering of a large catheter across the aorta and deployment of the transcatheter prosthesis within a calcified aortic valve, may be one of the pathophysiological mechanisms of acute kidney injury (AKI) complicating transcatheter aortic valve implantation (TAVI).

OBJECTIVE

To investigate the association between the atherosclerotic burden and plaque characteristics of the aortic valve and thoracic aorta, evaluated with multidetector CT (MDCT), and the occurrence of AKI after TAVI.

METHODS

Aortic valve calcification, atherosclerosis burden, and plaque characteristics of the thoracic aorta (including aortic root, ascending aorta, aortic arch, and descending aorta) were analyzed in preprocedural MDCT data of 210 TAVI patients (age, 81 ± 7.1 years; 51.4% men). The thoracic aorta was divided into ascending aorta, aortic arch, and descending thoracic aorta which was further divided into 5 to 8 segments according to the posterior intercostal arteries. Each segment where the maximum wall thickness exceeded ≥ 2 mm was defined as diseased segment with atherosclerotic plaque. Aortic atherosclerosis burden was defined as the proportion of thoracic aortic segments with atherosclerosis. AKI was defined by a creatinine level ≥ 1.5 × baseline or ≥ 26.4 μmol/L above baseline. MDCT data were correlated with the occurrence of postprocedural AKI in a multivariate logistic regression model.

RESULTS

Postprocedural AKI occurred in 51 patients (24.3%). In patients with AKI, the burden of overall (87.5% [75%-90%] vs 71.4% [50%-87.5%]; P < .001) and noncalcified atherosclerosis (42.9% [22.2%-62.5%] vs 12.5% [0%-28.6%]; P < .001) and the maximum plaque thickness (5.7 ± 1.8 mm vs 4.5 ± 1.4 mm; P < .001) were larger compared with patients without AKI. The burden of noncalcified atherosclerosis remained independently associated with AKI (odds ratio, 1.03 [per each 1% of increase in aortic segments with noncalcified atherosclerosis]; 95% confidence interval 1.01-1.05; P = .006) after adjusting for baseline renal function, logistic EuroSCORE, and procedural access. In contrast, aortic valve calcification was not independently associated with AKI.

CONCLUSION

In patients undergoing TAVI, occurrence of postprocedural AKI was associated with the extent of noncalcified atherosclerotic plaque burden of the thoracic aorta.

Associations of atherosclerosis in the descending thoracic aorta on CTA with arterial stiffness and chronic kidney disease in asymptomatic patients with diabetes mellitus

The relation between atherosclerosis in the descending thoracic aortic (DTA), arterial stiffness and chronic kidney disease (CKD) in patients with diabetes mellitus (DM) remains unclear. The current aim was to evaluate associations of DTA atherosclerosis with arterial stiffness and parameters of CKD in asymptomatic patients with DM. A total of 213 asymptomatic patients with diabetes (mean age 52 years, 56% men) underwent cardiovascular risk assessment including multi-slice computed tomography (for non-invasive coronary angiography, from which DTA atherosclerosis can be derived), non-invasive assessment of arterial stiffness with applanation tonometry and assessment of renal function. Measurements of DTA atherosclerosis included assessment of DTA thickening and calcium score. Arterial stiffness was determined by the carotid-femoral pulse wave velocity (PWV), parameters of CKD included estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR). DTA atherosclerosis was present in 180 (84%) patients. Patients with DTA atherosclerosis had increased arterial stiffness, lower eGFR and higher UACR values. After multivariate correction, DTA calcium score was independently associated with PWV (β = 0.18, p = 0.04). Furthermore, both DTA maximal wall thickness and DTA calcium score were independently associated with eGFR (β = -7.37, p < 0.001 and β = -1.99, p < 0.003, respectively), but not with UACR. The increase in arterial stiffness by atherosclerosis seemed to be mediated by arterial calcification, while the DTA calcium score was independently associated with arterial stiffness, but not DTA maximal wall thickness. Furthermore, parameters of CKD in patients with DM had a distinct relationship with DTA atherosclerosis: DTA atherosclerosis was associated with eGFR but not with UACR.