Cardiovascular disease in patients with chronic kidney disease: a neglected subgroup

The burden of non-communicable diseases has increased exponentially over the past decade and they account for majority of the health-related morbidity and mortality worldwide. In line with this, the prevalence of chronic kidney disease (CKD) has been increasing over the years. CKD progresses through stages and it is well known that patients are more likely to die than to progress to end-stage renal disease. The presence of multiple classical and novel risk factors predisposes this group of patients to premature cardiovascular mortality. Though being a common entity, prevention, diagnosis and treatment of cardiovascular diseases in CKD are mired with controversies. This is due to the fact that many of the well-established diagnostic modalities and treatment strategies have not been studied in detail in patients with CKD. Moreover, most of the studies have excluded patients with renal dysfunction though they are at a higher risk for adverse outcomes and require specific dose modifications. This has limited the evidence base for optimal decision making. In this review, we aim to cover the risk factors, diagnosis and effectiveness of interventional strategies in patients with CKD.

Revascularisation of patients with end-stage renal disease on chronic haemodialysis: bypass surgery versus PCI-analysis of routine statutory health insurance data

Objectives

We aimed to analyse the short-term and long-term outcome of patients with end-stage renal disease (ESRD) undergoing percutaneous intervention (PCI) as compared to coronary artery bypass surgery (CABG) to evaluate the optimal coronary revascularisation strategy.

Design

Retrospective analysis of routine statutory health insurance data between 2010 and 2012.

Main outcome measures

Primary outcome was adjusted all-cause mortality after 30 days and major adverse cardiovascular and cerebrovascular events at 1 year. Secondary outcomes were repeat revascularisation at 30 days and 1 year and bleeding events within 7 days.

Results

The total number of cases was n=4123 (PCI; n=3417), median age was 71 (IQR 62–77), 30.4% were women. The adjusted OR for death within 30 days was 0.59 (95% CI 0.43 to 0.81) for patients undergoing PCI versus CABG. At 1 year, the adjusted OR for major adverse cardiac and cerebrovascular events (MACCE) was 1.58 (1.32 to 1.89) for PCI versus CABG and 1.47 (1.23 to 1.75) for all-cause death. In the subgroup of patients with acute myocardial infarction (AMI), adjusted all-cause mortality at 30 days did not differ significantly between both groups (OR 0.75 (0.47 to 1.20)), whereas in patients without AMI the OR for 30-day mortality was 0.44 (0.28 to 0.68) for PCI versus CABG. At 1 year, the adjusted OR for MACCE in patients with AMI was 1.40 (1.06 to 1.85) for PCI versus CABG and 1.47 (1.08 to 1.99) for mortality.

Conclusions

In this cohort of unselected patients with ESRD undergoing revascularisation, the 1-year outcome was better for CABG in patients with and without AMI. The 30-day mortality was higher in non-AMI patients with CABG reflecting an early hazard with surgery. In cases where the patient's characteristics and risk profile make it difficult to decide on a revascularisation strategy, CABG could be the preferred option.

Efficacy and safety of warfarin in dialysis patients with atrial fibrillation: a systematic review and meta-analysis

Objective

To systematically review and meta-analyse the risk–benefit ratio of warfarin users compared with non-warfarin users in patients with atrial fibrillation (AF), who are undergoing dialysis.

Methods

We searched PubMed/MEDLINE, EMBASE, SCOPUS, Web of Science, Cochrane Library, grey literature, conference proceedings, trial registrations and also did handsearch. Cohort studies without language restrictions were included. Two investigators independently conducted a full abstraction of data, risk of bias and graded evidence. Effect estimates were pooled using random-effect models.

Main outcome measure

All-cause mortality, total stroke/thromboembolism and bleeding complications.

Results

14 studies included 37 349 dialysis patients with AF, of whom 12 529 (33.5%) were warfarin users. For all-cause mortality: adjusted HR=0.99 (95% CI 0.89 to 1.10; p=0.825), unadjusted risk ratio (RR)=1.00 (95% CI 0.96 to 1.04; p=0.847). For stroke/thromboembolism: adjusted HR=1.06 (95% CI 0.82 to 1.36; p=0.676), unadjusted incidence rate ratio (IRR)=1.23 (95% CI 0.94 to 1.61; p=0.133). For ischaemic stroke/transient ischaemic attack, adjusted HR=0.91 (95% CI 0.57 to 1.45; p=0.698), unadjusted IRR=1.16 (95% CI 0.84 to 1.62; p=0.370). For haemorrhagic stroke, adjusted HR=1.60 (95% CI 0.91 to 2.81; p=0.100), unadjusted IRR=1.48 (95% CI 0.92 to 2.36; p=0.102). Major bleeding was increased among warfarin users; adjusted HR=1.35 (95% CI 1.11 to 1.64; p=0.003) and unadjusted IRR=1.22 (95% CI 1.07 to 1.40; p=0.003).

Conclusions

Among dialysis patients with AF, warfarin therapy was not associated with mortality and stroke/thromboembolism, but significantly increased the risk of major bleeding. More rigorous studies are essential to demonstrate the effect of warfarin for stroke prophylaxis in dialysis patients with AF.

Endovascular management of renal artery aneurysms using the multilayer flow modulator

OBJECTIVE

Our aim was to describe our experience of the Multilayer Flow Modulator (MFM, Cardiatis, Isnes, Belgium) used in the treatment of type III renal artery aneurysms (RAA).

METHODS

This is a single-centre study. 3 patients (2 men and 1 woman; mean age 59 years; range 41-77 years) underwent treatment of a type III renal artery aneurysm using the MFM. The indications were a 23.9 mm type III RAA at the bifurcation of the upper and lower pole vessels, with 4 side branches; a 42.4 mm type III saccular RAA at the renal hilum; and a 23 mm type III RAA at the origin of the artery, supplying the upper pole.

RESULTS

Patients had a mean follow-up of 27 months, and were assessed by perioperative renal function tests, and repeat postoperative CT scan. There were no immediate postoperative complications or mortality. The first patient's aneurysm shrank by 8.6 mm, from 23.9 to 15.3 mm over 19 months, with all 4 side branches remaining patent. The largest aneurysm at 42.4 mm completely thrombosed, while the renal artery remained patent to the kidney. The final patient refused to have any follow-up scans but had no deterioration in renal function below 30 mL/min, and no further symptoms reported.

CONCLUSIONS

The MFM is safe and effective in the management of patients with complex renal artery aneurysms. The MFM can be used to treat branched or distal renal artery aneurysms with exclusion of the aneurysm from the circulation, while successfully preserving the flow to the side branches and kidney. Initial results are promising, however, longer follow-up and a larger cohort are required to prove the effectiveness of this emerging technology.

Subclinical cardiopulmonary dysfunction in stage 3 chronic kidney disease

OBJECTIVE

Reduced exercise capacity is well documented in end-stage chronic kidney disease (CKD), preceded by changes in cardiac morphology in CKD stage 3. However, it is unknown whether subclinical cardiopulmonary dysfunction occurs in CKD stage 3 independently of heart failure.

METHODS

Prospective observational cross-sectional study of exercise capacity assessed by cardiopulmonary exercise testing in 993 preoperative patients. Primary outcome was peak oxygen consumption (VO2peak). Anaerobic threshold (AT), oxygen pulse and exercise-evoked measures of autonomic function were analysed, controlling for CKD stage 3, age, gender, diabetes mellitus and hypertension.

RESULTS

CKD stage 3 was present in 93/993 (9.97%) patients. Diabetes mellitus (RR 2.49 (95% CI 1.59 to 3.89); p<0.001), and hypertension (RR 3.20 (95% CI 2.04 to 5.03); p<0.001)) were more common in CKD stage 3. Cardiac failure (RR 0.83 (95% CI 0.30 to 2.24); p=0.70) and ischaemic heart disease (RR 1.40 (95% CI 0.97 to 2.02); p=0.09) were not more common in CKD stage 3. Patients with CKD stage 3 had lower predicted VO2peak (mean difference: 6% (95% CI 1% to 11%); p=0.02), lower peak heart rate (mean difference:9 bpm (95% CI 3 to 14); p=0.03)), lower AT (mean difference: 1.1 mL/min/kg (95% CI 0.4 to 1.7); p<0.001) and impaired heart rate recovery (mean difference: 4 bpm (95% CI 1 to 7); p<0.001)).

CONCLUSIONS

Subclinical cardiopulmonary dysfunction in CKD stage 3 is common. This study suggests that maladaptive cardiovascular/autonomic dysfunction may be established in CKD stage 3, preceding pathophysiology reported in end-stage CKD.

Benefit of statin pretreatment in prevention of contrast-induced nephropathy in different adult patient population: systematic review and meta-analysis

Objective

Previous studies have suggested that statin pretreatment prevents contrast-induced nephropathy (CIN). However, single randomised trials are limited in their number of patients. This meta-analysis aims to assess the role of statin use in CIN prevention, as well as to determine patient subgroups that will benefit from statin pre-treatment.

Methodology

We searched PubMed, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomised controlled trials (RCT) comparing statin pretreatment versus placebo for preventing CIN. Our main outcome was the risk of CIN within 1–5 days after contrast administration.

Results

Data analysed from nine randomised studies with a total of 5143 patients, where 2559 received statins and 2584 received placebo, showed that statin pretreatment was associated with significant reduction in risk of CIN (MH-RR=0.47, 95% CI 0.34 to 0.64, Z=4.49, p<0.00001). This beneficial effect of statin was also seen in patients with baseline renal impairment (MH-RR=0.46, 95% CI 0.29 to 0.72, p=0.0008) and also those who were cotreated with NAC (MH-RR=0.46, 95% CI 0.25 to 0.83, p=0.01).

Conclusions

Statin pretreatment leads to significant reduction in CIN, and should be strongly considered in all patients who are planned for diagnostic and interventional procedures involving contrast-media administration.