Cholesterol crystal embolism: diagnosis and treatment

Effects of chronic kidney disease and post-angiographic acute kidney injury on long-term prognosis after coronary artery angiography

BACKGROUND

Both chronic kidney disease (CKD) and post-angiographic acute kidney injury (AKI) are regarded as risks factors for long-term mortality after coronary angiography. On the other hand, acute haemodynamic disturbances requiring haemodynamic support have a strong impact on both the incidence of AKI and on prognosis after coronary angiography. The aim of this study was to determine the impact of CKD and AKI on long-term prognosis after coronary angiography among hospital survivors and to determine relationships with haemodynamic variables.

METHODS

We studied 2439 patients who underwent coronary angiography or percutaneous coronary intervention. Relationships between both CKD and AKI and mortality or cardiovascular diseases were measured using unadjusted and adjusted Cox models for case-mix and laboratory variables.

RESULTS

Multivariable Cox regression analysis identified CKD as an independent predictor of long-term mortality [adjusted hazard ratio (AHR) 1.51; 95% confidence interval (95% CI) 1.07-2.13] and composite end points (AHR 1.72; 95% CI 1.40-2.11). Lower estimated glomerular filtration ratio levels below 50 mL/min/1.73 m(2) were significantly associated with mortality after adjustments. A similar association was found even in haemodynamically stable patients. AKI was also a predictor of long-term composite end points (AHR 1.64; 95% CI 1.09-2.46); however, its impact was attenuated in haemodynamically stable patients.

CONCLUSIONS

Among hospital survivors, CKD is an independent predictor for both long-term mortality and composite end points, regardless of haemodynamic conditions. AKI is also a predictor of long-term prognosis; however, its impact may be attenuated in haemodynamically stable hospital survivors.

Atheroembolic renal disease

Atheroembolic renal disease develops when atheromatous aortic plaques rupture, releasing cholesterol crystals into the small renal arteries. Embolisation often affects other organs, such as the skin, gastrointestinal system, and brain. Although the disease can develop spontaneously, it usually develops after vascular surgery, catheterisation, or anticoagulation. The systemic nature of atheroembolism makes diagnosis difficult. The classic triad of a precipitating event, acute or subacute renal failure, and skin lesions, are strongly suggestive of the disorder. Eosinophilia further supports the diagnosis, usually confirmed by biopsy of an affected organ or by the fundoscopic finding of cholesterol crystals in the retinal circulation. Renal and patient prognosis are poor. Treatment is mostly preventive, based on avoidance of further precipitating factors, and symptomatic, aimed to the optimum treatment of hypertension and cardiac and renal failure. Statins, which stabilise atherosclerotic plaques, should be offered to all patients. Steroids might have a role in acute or subacute progressive forms with systemic inflammation.

Lack of association between dialysis modality and outcomes in atheroembolic renal disease

BACKGROUND AND OBJECTIVES

Atheroembolic renal disease (AERD) can require dialytic support. Because anticoagulation may trigger atheroembolization, peritoneal dialysis may be preferred to hemodialysis. However, the effect of dialysis modality on renal and patient outcomes in AERD is unknown.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

A subcohort of 111 subjects who developed acute/subacute renal failure requiring dialysis was identified from a larger longitudinal study of AERD. The main exposure of interest was dialysis modality (peritoneal versus extracorporeal therapies). Logistic regression was used to study the probability of renal function recovery. Times from dialysis initiation to death were studied using Cox's regression.

RESULTS

Eighty-six patients received hemodialysis and 25 received peritoneal dialysis. The probability of renal function recovery was similar by dialysis modality (25% among hemodialysis patients and 24% among peritoneal dialysis patients; P = 0.873). During follow-up, 58 patients died, 14 among peritoneal patients and 44 among hemodialysis patients (P = 0.705). In multivariable analysis, gastrointestinal tract involvement and use of statins maintained an independent effect on the risk of patient death.

CONCLUSIONS

This study does not support the notion that one dialysis modality is superior to the other. However, the observational nature of the data precludes any firm conclusions.

Skin manifestations of internal disease

Internal diseases can manifest in a myriad of skin dermatoses ranging from single disorders such as calciphylaxis, cryoglobulinemia, amyopathic dermatomyositis, and Raynaud phenomenon, to spectrum disorders such as the neutrophilic dermatoses and morphea. In this article the underlying causes, triggering events, constitutional symptoms, clinical features and presentations, appearance at various stages, and pathogenesis are described. The course of the diseases and probable healing outcomes are outlined. Finally, examination and diagnostic methods, and therapies and treatments are provided.

Polyneuropathy associated with cholesterol crystal embolism

INTRODUCTION

Cholesterol crystal embolism complicating arterial catheterization usually presents as a multiorgan disease with renal failure, abdominal problems, and skin manifestations.

METHODS

We present a patient with hypertension and generalized arteriosclerosis who presented with muscle weakness, diffuse pain in the extremities, and renal failure 3 weeks after coronary catheterization and angioplasty of the right coronary artery. Muscle weakness progressed during the following months.

RESULTS

Nerve conduction studies and nerve biopsy showed severe axonal nerve injury. Biopsy of the kidney revealed the diagnosis of cholesterol crystal embolism.

CONCLUSION

The clinical presentation indicates a direct association of cholesterol crystal embolism and polyneuropathy. Although cholesterol crystal embolism represents a rare cause of polyneuropathy, it should be considered in patients with acute onset polyneuropathy and sudden onset multiorgan disease after arterial catheterization.

Cholesterol-crystal embolism presenting with delayed graft function and impaired long-term function in renal transplant recipients: two case reports

Introduction

Impaired renal function and/or pre-existing atherosclerosis in the deceased donor increase the risk of delayed graft function and impaired long-term renal function in kidney transplant recipients.

Case presentation

We report delayed graft function occurring simultaneously in two kidney transplant recipients, aged 57-years-old and 39-years-old, who received renal allografts from the same deceased donor. The 62-year-old donor died of cardiac arrest during an asthmatic state. Renal-allograft biopsies performed in both kidney recipients because of delayed graft function revealed cholesterol-crystal embolism. An empiric statin therapy in addition to low-dose acetylsalicylic acid was initiated. After 10 and 6 hemodialysis sessions every 48 hours, respectively, both renal allografts started to function. Glomerular filtration rates at discharge were 26 ml/min/1.73m² and 23.9 ml/min/1.73m², and remained stable in follow-up examinations. Possible donor and surgical procedure-dependent causes for cholesterol-crystal embolism are discussed.

Conclusion

Cholesterol-crystal embolism should be considered as a cause for delayed graft function and long-term impaired renal allograft function, especially in the older donor population.

[Atherosclerotic renal artery disease management update]

In the case of atherosclerotic renal artery disease, the best conclusive results lie principally not in the degree of the stenosis but rather in the degree the renal parenchymal disease beyond the stenosis itself. These determining factors involve the controlling of the patients blood pressure, the improvement in the renal function and the beneficial results to the cardiovascular system. Besides the indispensable medical treatment, a revascularisation by angioplasty may be indicated. This procedure with or without vascular stent often allows satisfactory angiographic results. A treatment by surgical revascularisation is only recommended in the case of extensive atherosclerotic lesions of the aorta, complex lesions of the latter or an abdominal aortic aneurism. Although the frequency of restenosis of angioplasty with stent remains extremely low, the risk of cholesterol emboli due to the diffuse atherosclerotic lesions of the abdominal aorta, must be considered at the time of each aortic catheterization. The therapeutic approach of atherosclerotic renal artery disease must be dictated by the whole cardiovascular risk factors and by the threat of target organs. The control of the blood pressure and the maintenance of the renal function must be integrated in the decisional algorithm as well as the possible risks in carrying out an eventual revascularisation procedure. Finally, the renal angioplasty should in numerous situations be integrated in the overall assumption of responsibility of the atherosclerotic vascular diseases, and should be part of the medical treatment. Several questions still do exist; at what moment an atherosclerotic renal artery stenosis should and e considered critical, and which procedure should be considered for which patient? The purpose of this review is to propose a decisional tool for individualized treatments in the light of results from randomized and controlled studies.

[Livedo: from pathophysiology to diagnosis]

PURPOSE

We propose a diagnostic approach when facing a livedo. First, the pathophysiology of the livedo is reviewed using key articles barely quoted in the literature. Then the topic is handled in two ways. Figures and tables allow a rapid reading convenient "at the patient's bedside". The subject is also reviewed thoroughly, and we emphasize the intricacy of the various pathophysiological mechanisms involved for each livedo's related disease. Diseases associated with livedo are then briefly described with emphasis on the key diagnostic features and prevalence. Usefulness of the main diagnostic procedures is discussed.

CURRENT KNOWLEDGE AND KEY POINTS

A livedo is a usually purplish-blue erythema, reticulated (small and complete meshes) or racemosa (large broken circular segments) which is related to a slowdown of the blood flow in the dermic venules. These venules form adjacent circles communicating with each other, parallel to the skin surface. The blood flow slowdown may be due to a local vasoconstriction (vasomotor livedo) or to an arteriolar occlusion. Arteriolar occlusion may be related to blood abnormalities (thrombosis, high viscosity, embolus) or to increased parietal thickness (vasculitis, calcic deposition, intimal hyperplasia). It is not always possible to clinically distinguish a vasomotor livedo from those associated with diseases. Diagnostic procedures should be oriented by the medical history, the features of the livedo, and associated symptoms. Usefulness of the skin biopsy is usually limited to the situations where the livedo is infiltrated or necrotic.

FUTURE PROSPECTS AND PROJECTS

To raise controversy about their importance and implications, some pathophysiological data are presented: intimal pseudohyperplasia in Sneddon's syndrome and antiphospholipid syndrome, and white cell activation in essential thrombocythemia.

The challenge of diagnosing atheroembolic renal disease: clinical features and prognostic factors

BACKGROUND

Atheroembolic renal disease (AERD) is caused by showers of cholesterol crystals released by eroded atherosclerotic plaques. Embolization may occur spontaneously or after angiographic/surgical procedures. We sought to determine clinical features and prognostic factors of AERD.

METHODS AND RESULTS

Incident cases of AERD were enrolled at multiple sites and followed up from diagnosis until dialysis and death. Diagnosis was based on clinical suspicion, confirmed by histology or ophthalmoscopy for all spontaneous forms and for most iatrogenic cases. Cox regression was used to model time to dialysis and death as a function of baseline characteristics, AERD presentation (acute/subacute versus chronic renal function decline), and extrarenal manifestations. Three hundred fifty-four subjects were followed up for an average of 2 years. They tended to be male (83%) and elderly (60% >70 years) and to have cardiovascular diseases (90%) and abnormal renal function at baseline (83%). AERD occurred spontaneously in 23.5% of the cases. During the study, 116 patients required dialysis, and 102 died. Baseline comorbidities, ie, reduced renal function, presence of diabetes, history of heart failure, acute/subacute presentation, and gastrointestinal tract involvement, were significant predictors of event occurrence. The risk of dialysis and death was 50% lower among those receiving statins.

CONCLUSIONS

Clinical features of AERD are identifiable. These make diagnosis possible in most cases. Prognosis is influenced by disease type and severity.