Importance of measuring the fractional flow reserve in patients receiving hemodialysis

Cardiovascular events in patients with deferred lesions and chronic kidney disease

No study has reported the association between the worsening of chronic kidney disease (CKD) and cardiovascular events in patients with deferred coronary artery lesions. We included patients with deferred lesions, defined as a fractional flow reserve (FFR) value > 0.80 treated with conservative medical therapy. Patients were divided into three groups: group 1, CKD stages 1-2; group 2, CKD stages 3-5; and group 3, CKD stage 5D (hemodialysis), with the clinical outcomes compared. The primary endpoint was the first occurrence of target vessel myocardial infarction, ischemia-driven target-vessel revascularization, or all-cause death. The primary endpoint was noted in 17, 25, and 36 patients in groups 1, 2, and 3, respectively. Within the three groups, the incidence rate of deferred lesions was 7.0%, 10.4%, and 32.4%, respectively. No difference was observed in the incidence of the primary endpoint between groups 1 and 2 (log-rank p = 0.16). However, the patients in group 3 had a significantly higher risk for the primary endpoint than those in groups 1 and 2 (log-rank p < 0.0001). In the multivariate Cox proportional hazards model, the patients in group 3 exhibited a higher incidence of the primary endpoint than those in group 1 (HR: 2.14; 95% CI 1.02-4.49; p < 0.01). Careful management is needed in patients undergoing hemodialysis, even if coronary artery stenosis is considered a deferred lesion.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Comparative Analysis of the Effect of Renal Function on the Spectrum of Coronary Artery Disease

BACKGROUND

We aim to assess the differential effect of renal impairment across the spectrum of patients with ischaemic heart disease and to study if any established risk factors may modify this risk.

METHODS

A total of 2013 patients who underwent revascularization for ST-segment elevation myocardial infarction or invasive physiology assessment were included. Renal impairment was defined as glomerular filtration rate less than 60 ml/min/1.73m². Clinical endpoints were prospectively collected, and the primary endpoint was defined as the composite endpoints of death, myocardial infarction, and unplanned revascularization.

RESULTS

593 (30%) presented with ST-segment elevation myocardial infarction, and 1362 (70%) stable patients had invasive ischaemia assessment which resulted in 37% receiving revascularization and 63% being deferred. Renal impairment was associated with increased adverse events in myocardial infarction [HR 1.77 (95% CI 1.15 to 2.74)], but not in the revascularized stable group [(HR 1.14 (95% CI 0.62 to 2.08)] or the deferred group [HR 1.31 (95% CI 0.84 to 2.03)]. There was an exponential increase in the future risk in ST-segment elevation myocardial infarction patients with severe renal dysfunction (glomerular filtration rate < 30) compared to a linear relationship in stable patients. Age and hypertension were the only two factors that had a differential impact across three groups (P<0.05 for interactions), with inconsistent directional effect of hypertension between medically managed and revascularized groups.

CONCLUSIONS

The magnitude of risk of renal impairment varies according to the clinical presentation of coronary artery disease with more weighted risk in myocardial infarction compared to stable patients.

The assessment of coronary artery disease in patients with end-stage renal disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in patients with ESRD. Coronary artery disease (CAD) is a key disease process, present in ∼50% of the haemodialysis population ≥65 years of age. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. For this reason, the most appropriate approach to the investigation of CAD is the subject of considerable discussion, with practice patterns largely varying between different centres. Traditional imaging modalities are limited in their diagnostic accuracy and prognostic value for cardiac events and survival in patients with ESRD, demonstrated by the large number of adverse cardiac outcomes among patients with negative test results. This review focuses on the current understanding of CAD screening in the ESRD population, discussing the available evidence for the use of various imaging techniques to refine risk prediction, with an emphasis on their strengths and limitations.

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.

Usefulness of Everolimus-Eluting Coronary Stent Implantation in Patients on Maintenance Hemodialysis

The outcomes of second-generation drug-eluting stent (DES) are unknown in patients on maintenance hemodialysis (HD) although HD has been reported as a strong predictor of adverse outcome after the first-generation DES implantation. The OUCH-PRO Study is a prospective multicenter single-arm registry design to study clinical and angiographic outcomes after everolimus-eluting stent (EES). Patients who underwent maintenance HD were prospectively enrolled at the time of elective coronary intervention using EES. Quantitative coronary angiography was performed in an independent core laboratory. The primary end point was the occurrence of target vessel failure (TVF) defined as cardiac death, myocardial infarction (MI), and target vessel revascularization at 1 year. A total of 123 patients were enrolled and 161 EES were implanted. The TVF rate at 1 year was 18% (4% cardiac death, 0% MI, 17% target vessel revascularization). No stent thrombosis was documented. Other clinical events at 1 year were 3% noncardiac death, 3% stroke, and 9% non-target-vessel revascularization. Late lumen loss in stent was 0.37 ± 0.63 mm at 8 months. In conclusion, EES had a high TVF rate and great late lumen loss in patients on HD compared with previous huge EES data in non-HD patients.