Nicorandil for the prevention of contrast-induced nephropathy: A meta-analysis of randomized controlled trials

Prevention of contrast-associated acute kidney injury in an era of increasingly complex interventional procedures

Radiological and interventional cardiology procedures are in continuous expansion, leading to an important increase in the incidence of contrast-associated acute kidney injury (CA-AKI). Although numerous methods of CA-AKI prevention have been studied, at present, there is no consensus on the definition of this entity or on its prevention. In this paper, we aim to provide a critical analysis of the existing data on the epidemiology, pathophysiology, and clinical significance of CA-AKI. Existing and emergent approaches for CA-AKI prevention are also discussed, with a focus on parenteral fluid administration and on the most recent clinical and experimental data. We also emphasize a number of questions that remain to be answered, and we identify hotspots for future research.

Oral Nicorandil effectively attenuates the incidence of contrast-induced nephropathy in patients undergoing cardiac catheterization: a randomized, controlled, open-label clinical trial

PURPOSE

The contrast-induced nephropathy (CIN) rate is increasing globally and can increase the rate of mortality and long-term problems. This study aims to determine the effect of Nicorandil on preventing CIN among patients undergoing cardiac catheterization.

METHODS

In a controlled randomized open-labeled clinical trial, all included patients undergoing cardiac catheterization due to coronary problems and possessing at least two risk factors of contrast nephropathy were divided into two groups of intervention and control. The intervention group received oral Nicorandil and normal saline, while the control group was treated with intravenous normal saline. Serum creatinine was measured before and 48 h after the procedure, and patients were assessed regarding CIN.

RESULTS

In this study, 172 patients entered each group; 41.86% and 45.34% were male in the control and Nicorandil groups. We showed that the incidence of CIN was meaningfully lower in the Nicorandil group (12, 7%) than in the control group (34, 19.8%, P = 0.001). Additionally, the incidence of CIN was notably lower in the female patients in the Nicorandil (85.7%) than in the control group (14.3%, P = 0.001); however, these numbers were not significantly different among men (64.0% and 36.0%, respectively, P = 0.850). After the injection of the contrast agent, the serum levels of blood urea nitrogen (P = 0.248), creatinine (P = 0.081), and glomerular filtration rate (P = 0.386) showed no significant differences between the control and Nicorandil groups. Multivariate regression analysis showed that Nicorandil significantly lowered the odds of CIN [odds ratio (OR) = 0.299, 95% confidence interval (CI) 0.149-0.602; P = 0.001] after adjustment for baseline creatinine (OR = 1.404, 95% CI 0.431-4.572; P = 0.574).

CONCLUSION

Our results indicate that pre-procedural treatment with Nicorandil may be effective against CIN in contrast to agent-exposed patients.

Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury

Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.

Canadian Association of Radiologists Guidance on Contrast-Associated Acute Kidney Injury

Purpose

Iodinated contrast media is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after iodinated contrast administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow-up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations.

Information sources

Published literature, including clinical trials, retrospective cohort series, review articles, and case reports, along with expert opinions from radiologists and nephrologists across Canada.

Methods

The leadership of the CAR formed a working group of radiologists and nephrologists with expertise in contrast administration and patient management related to contrast-associated AKI. We conducted a comprehensive review of the published literature to evaluate the evidence about contrast as a cause of AKI, and to inform evidence-based recommendations. Based on the available literature, the working group developed consensus recommendations.

Key Findings

The working group developed 21 recommendations, on screening, choice of iodinated contrast media, prophylaxis, medication considerations, and post contrast administration management. The key changes from the 2012 guidelines were (1) Simplification of screening to a simple questionnaire, and not delaying emergent examinations due to a need for creatinine measurements (2) Prophylaxis considerations only for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 (3) Not recommending the routine discontinuation of any drugs to decrease risk of AKI, except metformin when eGFR is less than 30 mL/min/1.73 m2 and (4) Not requiring routine follow up serum creatinine measurements post iodinated contrast administration.

Limitations

We did not conduct a formal systematic review or meta-analysis. We did not evaluate our specific suggestions in the clinical environment.

Implications

Given the importance of iodinated contrast media use in diagnosis and management, and the low risk of AKI after contrast use, these guidelines aim to streamline the processes around iodinated contrast use in most clinical settings. As newer evidence arises that may change or add to the recommendations provided, the working group will revise these guidelines.

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.

tert-Butylhydroquinone Treatment Alleviates Contrast-Induced Nephropathy in Rats by Activating the Nrf2/Sirt3/SOD2 Signaling Pathway

Oxidative stress plays a critical role in the pathophysiology of contrast-induced nephropathy (CIN). Since the specific treatment of CIN remains an unmet medical need, it is imperative to find an effective strategy against the clinical management of CIN. The transcription factor Nrf2 is known to regulate antioxidative stress response. The aim of the present study was to assess the effects of tert-butylhydroquinone (t-BHQ), an activator of Nrf2, in the prevention of CIN and elucidate the underlying mechanism of its action in vitro and in vivo. We established a rat model of CIN and treated the animals with t-BHQ (25 mg/kg). The effects of t-BHQ treatment on CIN rats were elucidated by assessing renal function, HE staining, immunohistochemistry, and western blotting. We also studied the activity of oxidative stress-related markers, such as intracellular ROS level, MDA level, SOD2 activity, and GSH/GSSG ratio. We validated our results by siRNA-mediated silencing of Nrf2 in HK-2 cells exposed to the radiocontrast agent. Treatment with t-BHQ significantly ameliorated the renal function and the histopathological lesions in CIN rats. Further, pretreatment with t-BHQ significantly increased the SOD2 activity and GSH/GSSG ratio and decreased the levels of ROS and MDA in animals subjected to ioversol exposure. In addition, t-BHQ treatment increased the expression of Nrf2, Sirt3, and SOD2 and concomitantly decreased the expression of acetylated-SOD2. When Nrf2-silenced HK-2 cells were exposed to radiocontrast agent, they suffered severe cell oxidative stress, exhibited lower expression of Sirt3 and SOD2, and expressed higher levels of acetylated-SOD2; however, t-BHQ treatment did not affect the protein expression of these indicators in si-Nrf2 HK-2 cells. Our findings suggested that Nrf2 plays an important role in the regulation of the Sirt3/SOD2 antioxidative pathway, and t-BHQ may be a potential agent to ameliorate radiocontrast-induced nephropathy via activating the Nrf2/Sirt3/SOD2 signaling pathway in vitro and in vivo.

Efficacy of nicorandil on the prevention of contrast-induced nephropathy in patients with coronary heart disease undergoing percutaneous coronary intervention

OBJECTIVES

The purpose of this study was to explore the effect of nicorandil on the incidence of contrast-induced nephropathy in patients with coronary heart disease undergoing percutaneous coronary intervention.

METHODS

This study randomized 300 patients undergoing percutaneous coronary intervention to receive conventional treatment in the control group (hydration only; n = 150) vs. nicorandil therapy (nicorandil 10 mg three times daily plus hydration; n = 150). The primary endpoint was the incidence of contrast-induced nephropathy, defined as rise in serum creatinine ≥44.2 μmol/L or >25% above baseline within 72 hours after exposure to contrast administered during percutaneous coronary intervention. Secondary endpoints included differences in post-percutaneous coronary intervention serum creatinine, blood urea nitrogen, creatinine clearance rate, cystatin-C, and occurrence of major adverse events.

RESULTS

Contrast-induced nephropathy incidence was 3.3% (5/150) in the nicorandil group vs. 10.7% (16/150) in the control group (P < 0.05). At 48 and 72 hours after contrast administration, cystatin-C levels were significantly lower and creatinine clearance rate were significantly higher with nicroandil therapy compared to conventional treatment (all P values <0.05). No statistical difference was observed in the incidence of major post-procedure side effect events in hospital and fourteen days of follow-up period between the nicorandil group and control group (3.3% vs. 4.0%, P > 0.05).

CONCLUSION

Compared to conventional treatment, oral nicorandil therapy was associated with less contrast-induced nephropathy and improved renal function following contrast administration during percutaneous coronary intervention.