Coronary Plaque Characteristics in Hemodialysis-Dependent Patients as Assessed by Optical Coherence Tomography

Transradial intervention in dialysis patients undergoing percutaneous coronary intervention: a Japanese nationwide registry study

Aims

Transradial intervention (TRI) for percutaneous coronary intervention (PCI) is used to reduce periprocedural complications. However, its effectiveness and safety for patients on dialysis are not well established. We aimed to investigate the association of TRI with in-hospital complications in dialysis patients undergoing PCI.

Methods and results

We included 44 462 patients on dialysis who underwent PCI using Japanese nationwide PCI registry data (2019-21) regardless of acute or chronic coronary syndrome. Patients were categorized based on access site: TRI, transfemoral intervention (TFI). Periprocedural access site bleeding complication requiring transfusion was the primary outcome and in-hospital death, and other periprocedural complications were the secondary outcomes. Matched weighted analysis was performed for TRI and TFI. Here, 8267 (18.6%) underwent TRI, and 36 195 (81.4%) underwent TFI. Patients who received TRI were older and had lower rates of comorbidities than those who received TFI. Access site bleeding rate and in-hospital death were significantly lower in the TRI group (0.1% vs. 0.7%, P < 0.001; 1.8% vs. 3.2%, P < 0.001, respectively). After adjustment, TRI was associated with a lower risk of access site bleeding (odds ratio [OR] [95% confidence interval (CI)]: 0.19 [0.099-0.38]; P < 0.001) and in-hospital death (OR [95% CI]: 0.79 [0.65-0.96]; P = 0.02). Other periprocedural complications between TRI and TFI were not significantly different.

Conclusion

In patients undergoing dialysis and PCI, TRI had a lower risk of access site bleeding and in-hospital death than TFI. This suggests that TRI may be safer for this patient population.

Plasma asymmetric dimethylarginine is associated with vulnerable plaque and long-term outcomes in stable coronary artery disease

Asymmetric dimethylarginine (ADMA) is considered to be an atherogenic molecule. We aimed to investigate the relationship between ADMA and plaque vulnerability assessed by optical coherence tomography (OCT) in patients with stable coronary artery disease (CAD). Two hundred and forty-five patients with stable CAD undergoing OCT-guided percutaneous coronary intervention were included in this study and were divided into two groups according to their ADMA levels. Micro-vessel, macrophage accumulation, thin-cap fibroatheroma, intra-plaque calcium and lipid core content, and vulnerable score (VS) were evaluated by OCT analysis. The patients with higher ADMA levels had significantly higher calcium and lipid content (p < 0.001, respectively). There were significantly more micro-vessel and macrophage (32.8%, p = 0.004 and 52.5%, p < 0.001, respectively) and higher VS (87.7 ± 17.6, p < 0.001) in the higher ADMA group. Moreover, plasma ADMA level was significantly correlated with the intra-plaque lipid, calcium content and VS (p < 0.001, respectively). Plasma ADMA level was identified as an independent predictor of future adverse cardiovascular events, following OCT-guided PCI. In patients with stable CAD, higher plasma ADMA levels were significantly associated with the presence of intra-plaque lipid, calcification, vulnerable plaque, and poor long-term outcomes.

Impact of calcified nodule on target lesion failure after stent implantation in hemodialysis patients

BACKGROUND

Little is known about intravascular imaging predictors of cardiac events after drug-eluting stent (DES) implantation in hemodialysis (HD) patients. We aimed to reveal the association between calcified nodules (CN) and target lesion failure (TLF) in HD patients after DES implantation.

METHODS

We enrolled 114 HD patients who underwent DES implantation between October 2016 and October 2020. The patients were divided into a CN group (39%, 44 patients) and a non-CN group (61%, 70 patients). The primary endpoint was the incidence of TLF, including cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization.

RESULTS

HD duration was longer, and the calcium burden was higher in the CN group than in the non-CN group. Over a median follow-up of 607 days [interquartile range: 349-965 days], the cumulative incidence curve showed that the CN group had a significantly higher incidence of TLF than the non-CN group (31.8% vs. 11.4% within 3 years, p = 0.008).　On Fine-Gray sub-distribution hazard model analysis, the CN group was associated with an increased rate of TLF (hazard ratio [HR]: 2.86; 95% confidence interval [CI]: 1.21-6.75, p = 0.016). An in-stent CN was observed in 73% of the lesions with target lesion revascularization in the CN group, whereas no in-stent CN was observed in the non-CN group (p = 0.026).

CONCLUSIONS

CN was an independent predictor of TLF in patients undergoing HD. In-stent CN was an important cause of TLF after DES implantation in CN lesions in HD patients; therefore, a different strategy should be considered for treating the lesions.

Impact of Hemodialysis Duration on Coronary Artery Calcification Among Hemodialysis Patients Who Underwent Percutaneous Coronary Intervention

Our study aimed to evaluate the prevalence and impact of coronary artery calcification (CAC) on hemodialysis (HD) patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). We enrolled 211 HD patients who underwent PCI (men: n = 155, age: 71 ± 1 0 years). Severe CAC was defined as calcification with an arc of 360° on intravascular ultrasound. Multivariate analysis was performed to determine the predictors of severe CAC. The impact of severe CAC on target lesion revascularization (TLR) was evaluated. Patients with severe CAC (46%) had a higher incidence of diabetes mellitus (DM) (79 vs 59%, P = .003) and longer HD duration (7.7 vs 3.4 years, P < .001) than those with non-severe CAC. Multivariate analysis demonstrated that DM, HD duration, and angiographic calcification were significant predictors for severe CAC (odds ratio 4.42, 1.13, and 6.62; P < .001, P < .001, and P < .001, respectively). After the median follow-up period of 580 days (interquartile range, 302-730 days), Kaplan-Meier curve analysis revealed that severe CAC was associated with an increased risk for TLR (χ² 12.7; P = .002). In HD patients with CAD after PCI, DM and HD duration were significant predictors for severe CAC. Furthermore, severe CAC was associated with an increased risk for TLR.

Prevalence, predictors, and outcomes of in-stent restenosis with calcified nodules

BACKGROUND

Calcified nodules (CN) have been reported as being associated with stent failure including in-stent restenosis (ISR). However, there is no systematic study of this condition.

AIMS

We aimed to clarify the prevalence, predictors, and midterm results of ISR lesions with CN.

METHODS

We examined the clinical characteristics of 651 ISR lesions in patients who underwent percutaneous coronary intervention (PCI) with optical coherence tomography (OCT) between October 2008 and July 2016, and their 6- to 8-month follow-up angiography results. CN was defined as a high backscattering mass with small nodular calcium depositions which protruded into the vessel lumen.

RESULTS

Thirty-two ISR lesions (4.9%) had CN. Multivariable analysis showed that calcified lesion (odds ratio [OR] 12.441, p<0.001), incomplete stent apposition (OR 3.228, p=0.005), haemodialysis (OR 3.633, p=0.024), and female gender (OR 3.212, p=0.036) were independently associated with ISR lesions with CN. Midterm follow-up was performed on 612 ISR lesions. Both ISR and target lesion revascularisation (TLR) rates were significantly higher in lesions with CN compared with those without CN (43.8% vs 25.0%, p=0.023; 37.5% vs 18.8%, p=0.020, respectively). However, multivariate analysis did not show the presence of CN as an independent predictor of re-TLR (OR 1.690, p=0.286).

CONCLUSIONS

The prevalence of ISR lesions with CN was 4.9%. Calcified lesions, incomplete stent apposition, haemodialysis, and female gender are probably associated with CN formation. ISR lesions with CN may have poor midterm outcomes compared with ISR lesions without CN.

APOL1 Genetic Variants Are Associated With Increased Risk of Coronary Atherosclerotic Plaque Rupture in the Black Population

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Fibroblast Growth Factor 21 Predicts and Promotes Vascular Calcification in Haemodialysis Patients

Background

Cardiovascular disease (CVD) is the leading cause of death in haemodialysis (HD) patients. Vascular calcification (VC) is dramatically accelerated and is strongly associated with CVD events and mortality in HD patients. VC coexists with osteoporosis in many studies. Fibroblast growth factor 21 (FGF21) which is known as an adipocytokine is a new hypoglycemic strategy and is inversely related to bone mineral density.

Methods

To evaluate the contribution of FGF21 to VC in HD patients, we detected circulating FGF21 levels and measured the whole thoracic aorta calcification scores (TACS) and calcification scores of the 3 segments of thoracic aorta, including ascending thoracic aorta (ATACS), aortic arch (AoACS), and descending thoracic aorta (DTACS) of our HD patients in this cross-sectional study. In addition, we pre-incubated human aortic endothelial cells (HAECs) with FGF21 in the presence or absence of parathyroid hormone (PTH) in vitro.

Results

The median serum FGF21 level in HD patients was 11-fold higher than that in healthy controls. Ln(FGF21) was positively correlated with Ln(TACS+1), Ln(ATACS+1), Ln(AoACS+1), and Ln(DTACS+1), respectively, in HD patients. Serum FGF21 was independently associated with TACS and ATACS, AoACS, and DTACS. FGF21 which was combined with age, calcium, and intact PTH demonstrated a high area under the curve of 0.84 with optimal sensitivity (84%) and specificity (71%) for the prediction of VC in HD patients. Our vitro results showed that FGF21 enhanced the calcification effect of PTH on HAECs by increasing calcium deposition and endothelial-to-mesenchymal transition.

Conclusions

Circulating FGF21 was notably higher and was a potential predictor and promoter of VC in HD patients.

Formation of Calcified Nodule as a Cause of Early In-Stent Restenosis in Patients Undergoing Dialysis

Background Dialysis is an independent risk factor for in-stent restenosis (ISR) after stent implantation in coronary arteries. However, the characteristics of ISR in patients undergoing dialysis remain unclear, as there are no histological studies evaluating the causes of this condition. The aim of the present study was to investigate the causes of ISR between patients who are undergoing dialysis and those who are not by evaluating tissues obtained from ISR lesions using directional coronary atherectomy. Methods and Results A total of 29 ISR lesions from 29 patients included in a multicenter directional coronary atherectomy registry of 128 patients were selected for analysis and divided into a dialysis group (n=8) and a nondialysis group (n=21). Histopathological evaluation demonstrated that an in-stent calcified nodule was a major histological characteristic of ISR lesions in the dialysis group and the prevalence of an in-stent calcified nodule was significantly higher in the dialysis group compared with the nondialysis group (75% versus 5%, respectively; P<0.01). On the other hand, the prevalence of an in-stent lipid-rich plaque was significantly lower in the dialysis group compared with the nondialysis group (0% versus 43%, respectively; P=0.03). In all cases with an in-stent calcified nodule, the underlying calcification before stent implantation was moderate to severe. When tissue characteristics were stratified according to duration post-stent implantation, an in-stent calcified nodule in the dialysis group was mainly observed within 1 year after stent implantation. Conclusions In-stent calcified nodules are a common cause of ISR in patients undergoing dialysis and are observed within 1 year after stent implantation, suggesting different causes of ISR between patients undergoing dialysis and those who are not.

Left coronary artery calcification patterns after coronary bypass graft surgery: An in-vivo optical coherence tomography study

OBJECTIVES

We sought to evaluate the severity and patterns of calcifications in the left main coronary artery (LMCA) and proximal segments of left anterior descending coronary artery (LAD) and left circumflex artery (LCX) using optical coherence tomography (OCT) in patients with and without prior coronary artery bypass grafting (CABG).

BACKGROUND

CABG may accelerate upstream calcium development.

METHODS

OCT images (n = 76) of the LMCA bifurcation from either the LAD or LCX in 76 patients with at least one patent left coronary graft, on average 7.0 ± 5.6 years post-CABG, were compared with 148 OCT images in propensity-score-matched non-CABG controls.

RESULTS

Minimum lumen areas in the LMCA, LAD, and LCX in post-CABG patients were smaller than non-CABG controls. Maximum calcium arc and thickness as well as calcium length were greater in the LMCA and LCX, but not in the LAD in post-CABG patients versus non-CABG controls. Calcium located at the carina of a bifurcation, calcified nodules (CN), thin intimal calcium, and lobulated calcium were more prevalent in post-CABG patients. After adjusting for multiple covariates, prior CABG was an independent predictor of calcification at the carina of a bifurcation (odds ratio [OR] 5.77 [95% confidence interval, CI: 1.5-21.6]), thin intimal calcium (4.7 [1.5-14.4]), and the presence of a CN (15.60 [3.2-76.2]).

CONCLUSIONS

Prior CABG is associated with greater amount of calcium in the LMCA and the proximal LCX, as well as higher prevalence of atypical calcium patterns, including CN, thin or lobulated calcium, and calcifications located at the carina of a bifurcation, compared with non-CABG controls.

An optical coherence tomography comparison of coronary arterial plaque calcification in patients with end-stage renal disease and diabetes mellitus

BACKGROUND

Coronary arterial plaques in patients with end-stage renal disease (ESRD) are assumed to have increased calcification due to underlying renal disease or initiation of dialysis. This relationship may be confounded by comorbid type 2 diabetes mellitus (DM).

METHODS

From a single-center OCT registry, 60 patients were analyzed. Twenty patients with ESRD and diabetes (ESRD-DM) were compared to 2 groups of non-ESRD patients: 20 with and 20 without diabetes. In each patient, one 20 mm segment within the culprit vessel was analyzed.

RESULTS

ESRD-DM patients exhibited similar calcium burden, arc, and area compared to patients with diabetes alone. When compared to patients without diabetes, patients with diabetes exhibited a greater summed area of calcium (DM: Median 9.0, IQR [5.3-28] mm2 vs Non-DM: 3.5 [0.1-14] mm2, p = 0.04) and larger calcium deposits by arc (DM: Mean 45 ± SE 6.2° vs Non-DM: 21 ± 6.2°, p = 0.01) and area (DM: 0.58 ± 0.10 mm2 vs Non-DM: 0.26 ± 0.10 mm2, p = 0.03). Calcification deposits in ESRD-DM patients (0.14 ± 0.02 mm) and patients with diabetes (0.14 ± 0.02 mm) were more superficially located relative to patients without diabetes (0.21 ± 0.02 mm), p = 0.01 for both.

CONCLUSIONS

Coronary calcification in DM and ESRD-DM groups exhibited similar burden, deposit size, and depth within the arterial wall. The increase in coronary calcification and cardiovascular disease events seen in ESRD-DM patients may not be secondary to ESRD and dialysis, but instead due to a combination of declining renal function and diabetes.

Characteristics of abnormal post-stent optical coherence tomography findings in hemodialysis patients

AIM

Clinical outcomes after percutaneous coronary intervention (PCI) in hemodialysis (HD) patients are significantly worse than those in non-HD patients. Optical coherence tomography (OCT) is a high resolution imaging modality and provides a detailed assessment of post-interventional abnormal findings that influence worse clinical outcomes. However, little is known about the abnormal post-stent OCT findings in HD patients. Therefore, in this study, we compared the abnormal post-stent OCT findings between HD and non-HD patients.

METHODS

One hundred thirty-nine consecutive OCT guided PCI (21 lesions in HD patients and 118 lesions in non-HD patients) were enrolled. We compared the post-stent OCT findings, including the edge dissections, under expansion index (minimum stent area/mean reference area), and stent eccentricity index (minimum stent diameter/maximum stent diameter) between HD and non-HD patients. We also compared the device-oriented clinical events (DoCEs) at 8 months of follow up.

RESULTS

There was a significantly higher prevalence of distal edge dissections (16.7% vs. 2.8%, P = 0.011) in HD patients. HD patients had a significantly lower under expansion index (0.76 ± 0.21 vs. 0.85 ± 0.14, P = 0.029) and stent eccentricity index (0.82 ± 0.09 vs. 0.88 ± 0.18, P = 0.018). The cumulative rate of DoCEs was significantly higher in the HD patients (23.8% vs. 5.2%, P = 0.013).

CONCLUSIONS

A higher prevalence of distal edge dissections, under expansion and stent eccentricity were detected by the detailed OCT findings in HD patients.