Multiple cholesterol emboli syndrome--six cases identified through the spontaneous reporting system

Cholesterol embolization syndrome: An under-recognized entity in cardiovascular interventions

Cholesterol embolization syndrome (CES) is a multi-systemic disease caused by embolization of atherosclerotic plaque contents from proximal large-caliber artery to distal small to medium arteries, occurring spontaneously or more commonly after vascular intervention. This report is a comprehensive review of the reported cases of CES found in our literature search. We discuss the risk factors, clinical manifestations, management, and prognosis of CES. The major predisposing factors for CES include older age, male sex, atherosclerotic cardiovascular risk factors, anticoagulation, and femoral access route. The composite incidence of atheroembolic renal disease was 92% and mortality 63%. Our review highlights the importance to recognize this disease entity for the cardiologist and nephrologist.

Contrast-induced nephropathy in percutaneous coronary interventions: pathogenesis, risk factors, outcome, prevention and treatment

Contrast-induced nephropathy (CIN) is a well-known adverse event of therapeutic and diagnostic procedures requiring the administration of contrast medium (CM). The lack of a universal CIN definition and glomerular filtration rate markers that vary have resulted in a variety of reported incidences. The development of CIN is associated with an increase in the length of hospital stay and the risk of death. Preexisting renal dysfunction, age, diabetes, congestive heart failure and the volume of CM administered are all associated with a risk for developing CIN. The literature suggests the use of low-osmolarity CM and supports volume supplementation before administration. Moreover, other strategies to avoid CIN, including treatment with N-acetylcysteine and sodium bicarbonate have variable levels of evidence. This review examines the main components of the pathogenesis and risk factors of CIN and possible preventive measures and therapies.

Atheroembolic disease--a frequently missed diagnosis: results of a 12-year matched-pair autopsy study

Diagnosis of atheroembolic disease (AD) is challenging, because no specific test is available and AD often masquerades as other clinical conditions. We conducted the current study to investigate the relative frequency of autopsy-proven AD over time, to describe its clinical presentation, and to identify risk factors for AD. We screened 2066 autopsy reports from 1995 to 2006 for AD. For each AD case, a control patient without AD was matched for age, sex, and autopsy year. Diagnostic and therapeutic interventions (surgery, catheter interventions, and drug treatment) in the last 6 months before death, as well as clinical and laboratory parameters during the last hospitalization, were retrieved from electronic charts. We identified 51 patients with AD. Among these only 6 (12%) had been diagnosed clinically. The organs most often affected were kidney (71%), spleen (37%), and lower gastrointestinal tract (22%). The relative AD frequency decreased over time from 3.5 to 0.5 per 100 autopsies, whereas the frequency of clinically suspected and biopsy-proven AD remained constant. Among clinical signs, skin lesions such as livedo reticularis and blue toe (33% vs. 14%; p = 0.04) were significantly increased in AD patients compared with the matched controls. We also observed a trend for higher incidence of eosinophilia and proteinuria in AD patients. Vascular interventions within 6 months before death were highly associated with AD (55% vs. 29%; p = 0.01), and in a multivariable analysis this remained the only significant risk factor for AD. Thus, the diagnosis of AD is frequently missed. Vascular interventions represent the most important risk factor for AD and should be performed restrictively in high-risk patients.

Epidemiology and prognostic implications of contrast-induced nephropathy

Contrast-induced nephropathy (CIN), usually defined as an increase in serum creatinine of 0.5 mg/dL (44.2 mumol/L), or a 25% increase from the baseline value 48 hours after the procedure, is a common and potentially serious complication of the use of iodinated contrast media in patients at risk of acute renal injury. It is an important cause of hospital-acquired renal failure, responsible for approximately 11% of cases. CIN may be difficult to distinguish from cholesterol embolization, another cause of postprocedure renal impairment. The reported incidence of CIN varies depending on the patient population studied. The impact of postprocedural renal impairment on clinical outcomes has been evaluated most extensively in patients undergoing percutaneous coronary intervention. CIN is associated with increased mortality both in hospital and at 1 year. A higher incidence of in-hospital and late cardiovascular events, as well as longer hospital stays, has been reported in patients developing CIN. In a small proportion of patients, CIN is severe enough to require dialysis, and these patients have a particularly poor prognosis. Many of the risk markers for CIN are also predictive of a worse prognosis.

Pathophysiology of contrast-induced nephropathy

Contrast-induced nephropathy (CIN) is the third leading cause of acute kidney injury in hospitalized patients and is associated with significant patient morbidity. The pathogenesis of CIN is complex and not fully understood, but iodinated contrast agents induce intense and prolonged vasoconstriction at the corticomedullary junction of the kidney. Moreover, high-osmolar dyes directly impair the autoregulatory capacity of the kidney through a loss of nitric oxide production. These effects, coupled with direct tubular toxicity of contrast media, lead to overt acute tubular necrosis and the syndrome of CIN.

Atheroembolic renal disease: clinical findings of 11 cases

Atheromatous embolism is a systemic disease resulting from cholesterol crystal embolization in many organs, including the kidneys. To characterize atheroembolic renal disease (AERD), we retrospectively evaluated 11 patients with acute renal failure after vascular surgery, vascular radiology investigations, and anticoagulation at Miyazaki Medical College from 1994 to 2001. The diagnosis of cholesterol atheromatous embolism was confirmed by tissue examination or clinical grounds. The patients were all elderly men (average age of 66.8 years) with a history of hypertension (55%), diabetes mellitus (45%), hyperlipidemia (45%), and coronary artery disease (18%). Seven patients had livedo reticularis, and 4 had blood eosinophilia. Clinically, 7 patients were managed conservatively and 5 of them improved, whereas 4 patients required dialysis and developed chronic renal failure or died. The serum creatinine levels of the improved patients were significantly lower (1.28+/-0.3 mg/dl, p < 0.005) than the non-improved ones (7.70+/-3.6). The number of eosinophils was significantly higher in the improved patients (576+/-295 /ml, p < 0.05) than in the non-improved ones (208+/-206). However, no significant difference was observed in the levels of serum cholesterol and C-reactive protein among these patients. Since the population at risk for AERD is growing, we should recognize this disease as a cause of acute renal failure.

Fatal lipid embolism following intraarterial angiography at an early stage of arteriosclerosis

Intraarterial angiography was performed on a patient with peripheral arterial occlusive disease (Fontaine IIb). No relevant risk factors were known, and a previous angiography had been undertaken without incident. After administration of contrast medium, the patient complained of acute pain in the lower abdomen and both legs, and a sudden rise in blood pressure was observed. The patient subsequently lost consciousness and died within 1.5 h. Postmortem examination showed that death was due to peripheral atheromatous microembolism of lipids, and not cholesterol as is usual in these cases. The differential diagnosis is discussed and a review of the literature is presented.