Complete versus partial distal embolic protection during renal artery stenting

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Endovascular versus medical therapy for atherosclerotic renovascular disease

The diagnosis of renal artery stenosis (RAS) has become increasingly common in part due to greater awareness of ischemic renal disease and increased use of diagnostic techniques. Over 90 % of RAS cases are caused by atherosclerotic renovascular disease (ARVD). Patients with ARVD are at high risk for fatal and nonfatal cardiovascular and renal events. The mortality rate in patients with ARVD is high, especially with other cardiovascular or renal comorbidities. Recent clinical studies have provided substantial evidence concerning medical therapy and endovascular interventional therapeutic approaches for ARVD. Despite previous randomized clinical trials, the optimal therapy for ARVD remained uncertain until the results of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial were released recently. CORAL demonstrated that optimal medical therapy was equally effective to endovascular therapy in the treatment of ARVD. Clinicians can now practice with more evidence-based medicine to treat ARVD and potentially decrease mortality in patients with ARVD using optimal medical therapy.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet treatment may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased.

OBJECTIVES

To summarise the effects of antiplatelet treatment (antiplatelet agent versus control or other antiplatelet agent) for the prevention of cardiovascular and adverse kidney outcomes in individuals with CKD.

SEARCH METHODS

In January 2011 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cochrane Renal Group's Specialised Register without language restriction.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet treatment versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data was pooled using the random-effects model.

MAIN RESULTS

We included 50 studies, enrolling 27,139 participants; 44 studies (21,460 participants) compared an antiplatelet agent with placebo or no treatment, and six studies (5679 participants) directly compared one antiplatelet agent with another. Compared to placebo or no treatment, antiplatelet agents reduced the risk of myocardial infarction (17 studies; RR 0.87, 95% CI 0.76 to 0.99), but not all-cause mortality (30 studies; RR 0.93, 95% CI 0.81 to 1.06), cardiovascular mortality (19 studies; RR 0.89, 95% CI 0.70 to 1.12) or stroke (11 studies; RR 1.00, 95% CI 0.58 to 1.72). Antiplatelet agents increased the risk of major (27 studies; RR 1.33, 95% CI 1.10 to 1.65) and minor bleeding (18 studies; RR 1.49, 95% CI 1.12 to 1.97). In terms of dialysis access outcomes, antiplatelet agents reduced access thrombosis or patency failure but had no effect on suitability for dialysis. Meta-regression analysis indicated no differences in the relative benefit or harms of treatment (risk of all-cause mortality, myocardial infarction, or major bleeding) by type of antiplatelet agent or stage of CKD. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, treatment in kidney transplant recipients, primary prevention, or risk of ESKD.

AUTHORS' CONCLUSIONS

Antiplatelet agents reduce myocardial infarction but increase major bleeding. Risks may outweigh harms among people with low annual risks of cardiovascular events, including those with early stages of CKD who do not have clinically-evident occlusive cardiovascular disease.

Clinical outcomes in patients with renal artery stenosis treated with stent placement with embolic protection compared with those treated with stent alone

PURPOSE

To compare the clinical outcomes in patients with chronic renal insufficiency (CRI) and renal artery stenosis (RAS) following renal artery (RA) stent placement with and without embolic protection device (EPD) usage.

MATERIALS AND METHODS

Eighteen patients who had RA stent placement with EPD were matched to control patients (RA stent only). Blood pressure, number of hypertensive medications, and estimated glomerular filtration rate (eGFR) at 3 months before the procedure and after 12 months were determined. An increase of ≥ 20% in eGFR at 12 months from baseline was defined as "improvement," decrease of ≥ 20% as "deterioration," and an eGFR change between those values as "stabilization" at 12 months.

RESULTS

At 12 months, stage 4 patients treated with EPD had significantly higher eGFR than controls (P = .01). There was no statistical difference in blood pressure outcomes between the 2 groups.

CONCLUSIONS

Patients with stage 4 CRI did significantly better with EPD than those treated without it.

The association between renal atherosclerotic plaque characteristics and renal function before and after renal artery intervention

OBJECTIVE

To evaluate the effect of plaque composition on renal function after renal artery intervention (RAI).

PATIENTS AND METHODS

In 33 consecutive patients with atherosclerotic renal artery stenosis (enrolled between January 1, 2007, and April 30, 2009), renal angiography, pressure gradients across the lesion, and intravascular ultrasonography (IVUS) with virtual histology (VH)-derived plaque characteristics were assessed. In 25 patients who underwent RAI, estimated glomerular filtration rate (eGFR) was evaluated at baseline and at 3 months.

RESULTS

Mean pressure gradients across the lesion were poorly associated with baseline eGFR (r=-0.37; P=.07). In gray scale IVUS data, only remodeling index was significantly correlated with baseline eGFR (r=-0.38; P=.03). Plaque components classified by VH-IVUS had no correlation with baseline eGFR. During follow-up of 25 patients, the improvement in eGFR after RAI was observed in 9 patients, unchanged in 3, and deteriorated in 13. Overall, follow-up eGFR (median, 49.0 mL/min/1.73 m(2); interquartile range [IQR], 40.6-63.9 mL/min/1.73 m(2)) was unchanged compared with baseline eGFR (median, 53.8 mL/min/1.73 m(2); IQR, 41.4-63.4 mL/min/1.73 m(2); P=.38). The percent change in eGFR (median, -0.2%; IQR, -16.0% to 16.0%) after RAI had a significant negative correlation with the mean percentage of necrotic core classified by VH-IVUS (r=-0.47; P=.02), and the mean percentage of necrotic core was significantly larger in patients with deterioration of eGFR than in patients without deterioration of eGFR (median, 12.7%; IQR, 9.5%-19.5%; vs median, 8.3%; IQR, 5.5%-11.6%; P=.04).

CONCLUSION

In patients with atherosclerotic renal artery stenosis, the change in eGFR after RAI was related to plaque composition classified by VH-IVUS. The evaluation of plaque composition may provide more insights into the change in renal function after RAI.

Primary stenting for atherosclerotic renal artery stenosis

INTRODUCTION

Endovascular treatment for atherosclerotic renal artery stenosis (ARAS) was first performed >30 years ago and its use has increased rapidly since then. However, only recently have large randomized trials rigorously evaluated its clinical benefit.

METHODS

We systematically reviewed the controlled studies on primary stenting for atherosclerotic renal artery stenosis. Studies were included if they compared the outcome of stenting with other treatments, or the outcome associated with different stent characteristics or stenting methods.

RESULTS

Stenting is preferred over angioplasty alone and over surgery when revascularization is indicated for ostial ARAS, except in cases of coexistent aortic disease indicating surgery. Randomized controlled trials showed no significant benefit and substantial risk of renal artery stenting over medication alone in patients with atherosclerotic ARAS without a compelling indication. Improvements in the procedure, such as with distal embolic protection devices and coated stents, are not associated with better clinical outcomes after stent placement for ARAS.

CONCLUSION

Recent evidence shows that impaired renal function associated with ARAS is more stable over time than previously observed. Optimal medical treatment should be the preferred option for most patients with ARAS. Only low-level evidence supports compelling indications for revascularization in ARAS, including rapidly progressive hypertension or renal failure and flash pulmonary edema.