Impact of Serum Phosphorus Levels on Outcomes After Implantation of Drug-Eluting Stents in Patients on Hemodialysis

Malnutrition leads to the progression of coronary artery calcification in hemodialysis patients

BACKGROUND

Malnutrition is considered a risk factor for cardiovascular disease in patients with chronic kidney disease. However, no in vivo studies have reported on using optical coherence tomography to evaluate the effect of nutritional status on coronary atherosclerosis in hemodialysis patients. We aimed to conduct a detailed analysis of the effect of nutritional status on the coronary arteries in hemodialysis patients.

METHODS

Among 64 hemodialysis patients who underwent percutaneous coronary interventions, 41 that underwent optical coherence tomography imaging were included in this study. And, among them, 24 patients that could also be evaluated using OCT also at the 6-month follow-up were included in this study. The patients were divided into two groups based on nutritional evaluation using the geriatric nutritional risk index. Culprit and non-culprit lesions were evaluated at baseline and after 6 months.

RESULTS

In the culprit lesions at baseline, the length of the lipid plaque was significantly smaller in the malnutrition group. In contrast, the thickness and length of the calcified plaque and the angle of the calcified nodule were significantly larger (each p < 0.01). In the non-culprit lesions, the 6-month change in the angle of the calcified plaque was significantly greater in the malnutrition group (p = 0.02). The significant factors that affected the change in the angle of calcification were "malnutrition at geriatric nutritional risk index" [odds ratio, 8.17; 95% confidence interval, 1.79 to 37.33; p < 0.01] and "serum phosphorus level" (odds ratio, 3.73; 95% confidence interval, 1.42 to 9.81; p < 0.01).

CONCLUSIONS

Appropriate management of nutritional status is crucial for suppressing the progression of coronary artery disease in hemodialysis 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.

Long-Term Clinical and Angiographic Outcomes After Implantation of New-Generation Drug-Eluting Stents for Patients on Maintenance Hemodialysis

Prior research has revealed poorer clinical outcomes after drug-eluting stent (DES) implantation for hemodialysis patients. This study aims to investigate the long-term clinical and angiographic outcomes after new-generation DES implantation for hemodialysis patients.We retrospectively enrolled 91 consecutive patients (118 lesions) who underwent successful new-generation DES (everolimus-, zotarolimus-, and biolimus-eluting stents) implantation for the first time. We measured the serum calcium and phosphorus levels in the blood samples obtained just before hemodialysis. The follow-up period of clinical events was, at least, 1.5 years. In this study, major adverse cardiac and cerebrovascular events (MACCE) and clinically driven target lesion revascularization were reported in 36 (39.6%) and 11 (12.1%) patients, respectively. The prevalence of peripheral artery disease was significantly higher in the MACCE group (41.7% versus 14.5%, P = 0.006). The serum calcium level was significantly higher in the MACCE group (9.34 ± 0.92 mg/dL versus 8.77 ± 0.88 mg/dL; P = 0.004). The multivariate Cox proportional hazards model revealed that the serum calcium level (hazard ratio, 1.86; 95% confidence interval [CI]: 1.26-2.77; P = 0.002), suboptimal (over 55 mg²/dL²) calcium-phosphorus product (hazard ratio, 3.27; 95% CI: 1.41-7.61; P = 0.006) and the coexistence of peripheral artery disease (hazard ratio, 3.15; 95% CI: 1.49-6.65; P = 0.003) were independent predictors of MACCE.For hemodialysis patients, MACCE remains a frequent occurrence after new-generation DES implantation and is associated with calcium-phosphate metabolism and peripheral artery disease.