Effect of statins in preventing contrast-induced nephropathy: an updated meta-analysis

Pharmacologic Prophylaxis of Contrast-Induced Nephropathy

Different pharmacologic agents have been tested in the effort to prevent contrast-induced acute kidney injury (AKI) in the last two decades. To date, however, no individual drug has received unanimous approval for this aim. Since 2014 statins have been included as preventive treatment in the European guidelines for revascularization procedures in cardiac patients. The present update presents the latest findings in this field focusing on the changing paradigms in the definition and consequently the approach to nephroprotection that considers clinical prognosis as the major issue. We note the current shift from attention to contrast-induced AKI to contrast-associated AKI.

Simvastatin Treatment in Traumatic Brain Injury: Operation Brain Trauma Therapy

Simvastatin, the fourth drug selected for testing by Operation Brain Trauma Therapy (OBTT), is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor used clinically to reduce serum cholesterol. In addition, simvastatin has demonstrated potent antineuroinflammatory and brain edema reducing effects and has shown promise in promoting functional recovery in pre-clinical models of traumatic brain injury (TBI). The purpose of this study was to assess the potential neuroprotective effects of oral administration of simvastatin on neurobehavioral, biomarker, and histopathological outcome measures compared across three pre-clinical TBI animal models. Adult male Sprague-Dawley rats were exposed to either moderate fluid percussion injury (FPI), controlled cortical impact injury (CCI), or penetrating ballistic-like brain injury (PBBI). Simvastatin (1 or 5 mg/kg) was delivered via oral gavage at 3 h post-injury and continued once daily out to 14 days post-injury. Results indicated an intermediate beneficial effect of simvastatin on motor performance on the gridwalk (FPI), balance beam (CCI), and rotarod tasks (PBBI). No significant therapeutic benefit was detected, however, on cognitive outcome across the OBTT TBI models. In fact, Morris water maze (MWM) performance was actually worsened by treatment in the FPI model and scored full negative points for low dose in the MWM latency and swim distance to locate the hidden platform. A detrimental effect on cortical tissue loss was also seen in the FPI model, and there were no benefits on histology across the other models. Simvastatin also produced negative effects on circulating glial fibrillary acidic protein biomarker outcomes that were evident in the FPI and PBBI models. Overall, the current findings do not support the beneficial effects of simvastatin administration over 2 weeks post-TBI using the oral route of administration and, as such, it will not be further pursued by OBTT.

Statins in the prevention of contrast-induced nephropathy

OPINION STATEMENT

Coronary angiography and percutaneous coronary interventions are common procedures that utilize iodinated contrast medium to visualize the coronary arterial tree and treat stable and unstable ischemic heart syndromes. Exposure to contrast agents can cause acute and persistent worsening of renal function leading to increased morbidity and mortality. Certain patient characteristics such as age, presence of diabetes, congestive heart failure, chronic kidney disease, hemodynamic instability on presentation, and type and volume of contrast used can increase the risk of developing contrast-induced nephropathy (CIN) and its subsequent complications. Despite the lack of a universal definition, CIN is typically defined as an increase in serum creatinine ≥0.5 mg/dL or 25 % above baseline 48 to 72 h after contrast exposure. Previous research has shown the benefits of adequate intravenous hydration with iso-osmolar crystalloids and the importance of limiting the amount of low-osmolar and iso-osmolar contrast used to prevent the development of CIN. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have anti-inflammatory and anti-apoptotic properties with few side effects, making it an attractive therapeutic option for prevention of CIN. A number of trials have examined the benefit of different types of statins, high-dose versus low-dose statins, loading versus chronic dosing of statins, in various clinical presentations including acute coronary syndromes and elective procedures, and in those with associated comorbidities such as anemia and chronic kidney disease. In this review, we will summarize recent data regarding statin therapy for prevention of contrast-induced nephropathy.

Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) represents an important adverse effect of contrast media (CM) administration. Contrast-induced nephropathy is associated with prolonged hospitalization as well as increased cardiovascular morbidity, renal morbidity, and all-cause mortality. Several risk factors may predict CIN incidence, and various scores and ratios have been proposed to identify high-risk patients. Novel biomarkers may provide an earlier diagnosis of CIN. A multifactorial approach is required for CIN prevention including hydration, administration of low- or iso-osmolar CM, minimizing CM volume, and statin administration. Renal function may deteriorate after CM administration, even in the absence of CIN. Therefore, this deterioration may not be an “all or none” phenomenon; it may well occur in many patients receiving CM, with/without CIN, and may prove to be an underestimated risk factor. Patients should be followed up for longer periods as outpatients after CM exposure to assess kidney function and predict subsequent increased morbidity and mortality.