Statin treatment before percutaneous cononary intervention

Shrinking Weibel-Palade bodies prevents high platelet recruitment in assays using thrombotic thrombocytopenic purpura plasma

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), caused by a genetic or autoimmune-driven lack of ADAMTS-13 activity, leads to high levels of the ultra-large von Willebrand factor (VWF) multimers produced by endothelial cells, causing excess platelet recruitment into forming thrombi, often with mortal consequences. Treatments include plasma infusion or replacement to restore ADAMTS-13 activity, or prevention of platelet recruitment to VWF.

OBJECTIVES

We tested a different approach, exploiting the unique cell biology of the endothelium. Upon activation, the VWF released by exocytosis of Weibel-Palade bodies (WPBs), transiently anchored to the cell surface, unfurls as strings into flowing plasma, recruiting platelets. Using plasma from patients with TTP increases platelet recruitment to the surface of cultured endothelial cells under flow. WPBs are uniquely plastic, and shortening WPBs dramatically reduces VWF string lengths and the recruitment of platelets. We wished to test whether the TTP plasma-driven increase in platelet recruitment would be countered by reducing formation of the longest WPBs that release longer strings.

METHODS

Endothelial cells grown in flow chambers were treated with fluvastatin, one of 37 drugs shown to shorten WPBs, then activated under flow in the presence of platelets and plasma of either controls or patients with TTP.

RESULT

We found that the dramatic increase in platelet recruitment caused by TTP plasma is entirely countered by treatment with fluvastatin, shortening the WPBs.

CONCLUSIONS

This potential approach of ameliorating the endothelial contribution to thrombotic risk by intervening far upstream of hemostasis might prove a useful adjunct to more conventional and direct therapies.

Urinary proteomics investigations into contrast-induced acute kidney injury

Some patients have a decline in renal function after contrast medium injection, and this phenomenon is called contrast-induced acute kidney injury (CI-AKI); a small number of people even suffer severe renal failure. To date, the mechanism of CI-AKI remains unclear. We aimed to identify novel potential biomarkers in the urine of patients with CI-AKI through LC-MS/MS and bioinformatics analysis. We enrolled patients who underwent coronary angiography (contrast agent: iohexol). The CI-AKI group included 4 cases, and the non-CI-AKI group included 20 cases. We mixed the 4 CI-AKI samples and 20 non-CI-AKI samples. Then, a 0.6 ml urine sample was used for proteome analysis with LC-MS/MS approach. Metascape, ExPASy, and the Human Protein Atlas were utilized for bioinformatics analysis. We obtained 724 and 830 urine proteins from the CI-AKI and non-CI-AKI groups, respectively. The distribution of the pI values and molecular weights (MWs) of postoperative urine proteins showed no significant difference between the CI-AKI group and the non-CI-AKI group. A total of 99differentially expressed proteins (DEPs) were detected, among which 18 proteins were detected only in tubule cells, and 19 proteins were detected in both tubule cells and glomeruli. With GO analysis, the GEPs were mainly associated with immune response and inflammation. Although biomarkers cannot be asserted from this single pilot study, our results may help advance the understanding of the mechanisms of CI-AKI and identify potential novel biomarkers for further investigation.

Beneficial effect of statin on preventing contrast-induced acute kidney injury in patients with renal insufficiency: A meta-analysis

BACKGROUND

Renal insufficiency is an important predictor of contrast-induced acute kidney injury (CI-AKI). We performed a meta-analysis to examine the effects of short-term statin therapy on the incidence of CI-AKI, particularly in patients with renal insufficiency.

METHODS

A systematic search was conducted to retrieve randomized controlled trials (RCTs) that investigated the impact of statin pretreatment before administration of contrast media on the development of CI-AKI in patients with mild to moderate renal insufficiency. The primary outcome was development of CI-AKI. The secondary outcome was the incidence ofacute kidney injury requiring hemodialysis.

RESULTS

Data analysis from 8 RCTs, which included a total of 2313 subjects in the statin-treated group and 2322 in the control group, showed that statin pretreatment was associated with significant reduction of the risk of CI-AKI (relative risk [RR] = 0.59; 95% confidential interval [CI] 0.44-0.79; P = .0003, I = 0%). A beneficial effect of statin on preventing CI-AKI was consistent, regardless of the dose of statin and use of N-acetylcysteine. In subgroup analysis based on baseline estimated glomerular filtration rate (eGFR), patients with baseline eGFR <60 mL/min/1.73 m (RR = 0.63; 95% CI 0.41-0.98; P = .04, I = 0%) and 30 < eGFR < 90 mL/min/1.73 m (RR = 0.56; 95% CI 0.39-0.82; P = .003, I = 0%) showed significant reduction of risk of CI-AKI.

CONCLUSION

Statin pretreatment is effective at preventing CI-AKI and should be considered in patients with preexisting renal insufficiency.

Efficacy of atorvastatin on the prevention of contrast-induced acute kidney injury: a meta-analysis

Background

Results of studies on the efficacy of atorvastatin pretreatment on reducing the prevalence of contrast-induced acute kidney injury (CIAKI) in patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI) have been controversial.

Objective

We undertook a meta-analysis to evaluate the efficacy of atorvastatin on contrast-induced nephropathy (CIN) after CAG or PCI.

Materials and methods

We undertook a systematic search of electronic databases (PubMed, Embase, and the Cochrane Library) up to June 2017. A meta-analysis was carried out including randomized controlled trials (RCTs) that compared atorvastatin pretreatment with pretreatment with a low-dose statin or placebo for CIAKI prevention in patients undergoing CAG. The main endpoint was CIN prevalence.

Results

Nine RCTs were included in our meta-analysis. Atorvastatin pretreatment reduced the prevalence of CIN significantly (odds ratio [OR] 0.46; 95% confidence interval [95% CI] 0.27–0.79; p=0.004). The benefit of high-dose atorvastatin pretreatment was consistent when compared with the control group (OR 0.45; 95% CI 0.21–0.95; p=0.04).

Conclusion

At high doses, atorvastatin pretreatment was associated with a significant reduction in the prevalence of CIAKI in patients undergoing CAG. Pretreatment with high-dose atorvastatin could be employed to prevent CIAKI.

Long-term statin use before primary percutaneous coronary intervention improves treatment outcomes of acute myocardial infarction

Numerous studies have reported that high-dose statin loading therapy prior to primary percutaneous coronary intervention (PPCI) improves the clinical outcomes of patients following acute myocardial infarction (AMI). However, little is known about the effects of long-term statin use prior to PPCI on such outcomes. Therefore, the aim of the present analysis was to clarify the effects of long-term statin use before PPCI on the treatment outcomes of patients following AMI. The records of 213 patients who had AMI and met the inclusion criteria were retrospectively reviewed. Patients were divided into two groups: A control group (n=178) who had received no statin pretreatment before AMI onset, and a statin group (n=35) who had received statin treatment for ≥1 month before AMI onset. All patients received a standard treatment regimen for the secondary prevention of coronary artery disease after PPCI. Baseline clinical variables, details of the PPCI procedure and clinical outcomes within 3 months after treatment were reviewed. Patients in the statin group were significantly older than those in the control group (P=0.003). Compared with the control group, there was a greater proportion of patients with hyperlipidemia and previous angina pectoris in the statin group. There were no differences in the use of other drugs (aspirin, β-blockers and angiotensin-converting enzyme inhibitors) prior to PPCI between the two groups. The corrected TIMI frame count (cTFC) was significantly lower in the statin group than in the control group (24.1±12.8 vs. 29.4±14.3, respectively; P=0.043). Multivariable linear regression analysis showed that long-term statin use before AMI was a significant predictor of cTFC after PPCI (P=0.012). Furthermore, the incidence of major adverse cardiac events within 3 months after PPCI was higher in the control group than in the statin group (16.8 vs. 2.9%, respectively; P=0.032). Logistic regression analysis showed that previous statin use was associated with the incidence of major adverse cardiac events within 3 months after treatment (P=0.012). The results of the present study demonstrate that long-term statin use prior to PPCI improved treatment outcomes after AMI in actual clinical practice.

Weibel-Palade body size modulates the adhesive activity of its von Willebrand Factor cargo in cultured endothelial cells

Changes in the size of cellular organelles are often linked to modifications in their function. Endothelial cells store von Willebrand Factor (vWF), a glycoprotein essential to haemostasis in Weibel-Palade bodies (WPBs), cigar-shaped secretory granules that are generated in a wide range of sizes. We recently showed that forcing changes in the size of WPBs modifies the activity of this cargo. We now find that endothelial cells treated with statins produce shorter WPBs and that the vWF they release at exocytosis displays a reduced capability to recruit platelets to the endothelial cell surface. Investigating other functional consequences of size changes of WPBs, we also report that the endothelial surface-associated vWF formed at exocytosis recruits soluble plasma vWF and that this process is reduced by treatments that shorten WPBs, statins included. These results indicate that the post-exocytic adhesive activity of vWF towards platelets and plasma vWF at the endothelial surface reflects the size of their storage organelle. Our findings therefore show that changes in WPB size, by influencing the adhesive activity of its vWF cargo, may represent a novel mode of regulation of platelet aggregation at the vascular wall.

Prevention of contrast-induced nephropathy through a knowledge of its pathogenesis and risk factors

Contrast-induced nephropathy (CIN) is an iatrogenic acute renal failure (ARF) occurring after the intravascular injection of iodinated radiographic contrast media. During the past several years, in many patients undergoing computed tomography, iodinated contrast media have not been used for the fear of ARF, thereby compromising the diagnostic procedure. But recent studies have demonstrated that CIN is rarely occurring in patients with normal renal function and that preexisting chronic renal failure and/or diabetes mellitus represent(s) predisposing condition(s) for its occurrence. After the description of CIN and its epidemiology and pathophysiology, underlying the important role played by dehydration and salt depletion, precautions for prevention of CIN are listed, suggested, and discussed. Maximum priority has to be given to adequate hydration and volume expansion prior to radiographic procedures. Other important precautions include the need for monitoring renal function before, during, and after contrast media injection, discontinuation of potentially nephrotoxic drugs, use of either iodixanol or iopamidol at the lowest dosage possible, and administration of antioxidants. A long list of references is provided that will enable readers a deep evaluation of the topic.

The Choice of the Iodinated Radiographic Contrast Media to Prevent Contrast-Induced Nephropathy

In patients with preexisting renal impairment, particularly those who are diabetic, the iodinated radiographic contrast media may cause contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI), that is, an acute renal failure (ARF), usually nonoliguric and asymptomatic, occurring 24 to 72 hours after their intravascular injection in the absence of an alternative aetiology. Radiographic contrast media have different osmolalities and viscosities. They have also a different nephrotoxicity. In order to prevent CIN, the least nephrotoxic contrast media should be chosen, at the lowest dosage possible. Other prevention measures should include discontinuation of potentially nephrotoxic drugs, adequate hydration with i.v. infusion of either normal saline or bicarbonate solution, and eventually use of antioxidants, such as N-acetylcysteine, and statins.

Acute kidney injury by radiographic contrast media: pathogenesis and prevention

It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure (ARF). We may define contrast-induced Acute Kidney Injury (AKI) as ARF occurring within 24-72 hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species (ROS), reduction of nitric oxide (NO) production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.

Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention

Radiocontrast media (RCM) are medical drugs used to improve the visibility of internal organs and structures in X-ray based imaging techniques. They may have side effects ranging from itching to a life-threatening emergency, known as contrast-induced nephropathy (CIN). We define CIN as acute renal failure occurring within 24-72 hrs of exposure to RCM that cannot be attributed to other causes. It usually occurs in patients with preexisting renal impairment and diabetes. The mechanisms underlying CIN include reduction in medullary blood flow leading to hypoxia and direct tubule cell damage and the formation of reactive oxygen species. Identification of patients at high risk for CIN is important. We have reviewed the risk factors and procedures for prevention, providing a long list of references enabling readers a deep evaluation of them both. The first rule to follow in patients at risk of CIN undergoing radiographic procedure is monitoring renal function by measuring serum creatinine and calculating the eGFR before and once daily for 5 days after the procedure. It is advised to discontinue potentially nephrotoxic medications, to choose radiocontrast media at lowest dosage, and to encourage oral or intravenous hydration. In high-risk patients N-acetylcysteine may also be given.