Is angiotensin-converting enzyme inhibitor a contraindication for contrast-induced nephropathy prophylaxis? A review about its paradox

The Impact of Angiotensin-Converting Enzyme Inhibitors or Angiotensin II Receptor Blockers on Clinical Outcomes of Acute Kidney Disease Patients: A Systematic Review and Meta-Analysis

Background: Acute kidney injury (AKI) may increase the risk of chronic kidney disease (CKD), development of end-stage renal disease (ESRD), and mortality. However, the impact of exposure to angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (ACEi/ARB) in patients experiencing AKI/acute kidney disease (AKD) is still unclear. Methods: In this systematic review, we searched all relevant studies from PubMed, Embase, Cochrane, Medline, Collaboration Central Register of Controlled Clinical Trials, Cochrane Systematic Reviews, and ClinicalTrials.gov until July 21, 2020. We evaluated whether the exposure to ACEi/ARB after AKI onset alters recovery paths of AKD and impacts risks of all-cause mortality, recurrent AKI, or incident CKD. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. Results: A total of seven articles, involving 70,801 patients, were included in this meta-analysis. The overall patient mortality rate in this meta-analysis was 28.4%. Among AKI patients, all-cause mortality was lower in ACEi/ARB users than in ACEi/ARB nonusers (log odds ratio (OR) -0.37, 95% confidence interval (CI): -0.42--0.32, p < 0.01). The risk of recurrent adverse kidney events after AKI was lower in ACEi/ARB users than in nonusers (logOR -0.25, 95% CI: -0.33--0.18, p < 0.01). The risk of hyperkalemia was higher in ACEi/ARB users than in nonusers (logOR 0.43, 95% CI: 0.27-0.59, p < 0.01). Patients with continued use of ACEi/ARB after AKI also had lower mortality risk than those prior ACEi/ARB users but who did not resume ACEi/ARB during AKD (logOR -0.36, 95% CI: -0.4--0.31, p < 0.01). Conclusions: Exposure to ACEi/ARB after AKI is associated with lower risks of all-cause mortality, recurrent AKI, and progression to incident CKD. Patients with AKI may have a survival benefit by continued use of ACEi/ARB; however, a higher incidence of hyperkalemia associated with ACEi/ARB usage among these patients deserves close clinical monitoring.

Impact of renin-angiotensin-aldosterone system-blocking agents on the risk of contrast-induced acute kidney injury: a prospective study and meta-analysis

OBJECTIVE

We sought to assess the impact of the pretreatment with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) for coronary intervention on the risk of contrast-induced acute kidney injury (CI-AKI) after 72-hour postcontrast administration, together with a comprehensive meta-analysis in this aspect.

METHODS AND RESULTS

In this prospective study, 401 patients referred for percutaneous coronary intervention were enrolled with 134 patients in non-renin-angiotensin-aldosterone system group, 204 patients in ACEIs group and 63 patients in ARBs group. For further meta-analysis, articles were identified through PubMed, EMBASE, Wanfang, and VIP. Data extraction and study quality were assessed in duplicate. Altogether, 14 qualified trials (including this prospective study) with 1960 patients taking ACEIs or ARBs and 1457 patients receiving no renin-angiotensin-aldosterone system blockers were analyzed. There was an overall 1.28-fold increased risk for CI-AKI in patients taking ACEIs or ARBs (odds ratio [OR] = 1.28; 95% confidence interval [CI], 0.79-2.09; P = 0.315). Overall changes in serum creatinine, estimated GFR, and blood urea nitrogen were also nonsignificant. Subgroup analyses identified a significantly increased risk for CI-AKI in patients taking ARBs (OR = 3.31; 95% CI, 1.89-5.78; P < 0.0005), and no significance was observed for patients taking ACEIs (OR = 0.86; 95% CI, 043-1.72; P = 0.664). Also, patients taking ARBs had serum creatinine markedly increased by 0.05 mg/dL (95% CI, 0.02-0.09; P = 0.005).

CONCLUSIONS

The findings of this meta-analysis provide clear evidence for a deleterious impact of ARBs on the development of CI-AKI.

The impact of renin-angiotensin-aldosterone system blockade on contrast-induced nephropathy: a meta-analysis of 12 studies with 4,493 patients

OBJECTIVES

This meta-analysis investigated the impact of renin-angiotensin-aldosterone system (RAAS) blockade on the occurrence of contrast-induced nephropathy (CIN).

METHODS

Twelve studies comparing the use of RAAS blockade in a total of 4,493 patients undergoing a contrast-using procedure were included. The primary endpoint was the overall postprocedural incidence of CIN.

RESULTS

In the overall pooled analysis, there was no significant difference between the two groups, RAAS blockade 'used' versus 'not-used', in the incidence of postprocedural CIN in the random-effects model (OR 1.27, 95% CI 1.77-2.11, p = 0.351, I(2) = 61.9%). In the stratified analysis, however, for chronic RAAS blockade users, the continuation of the drug was significantly associated with a higher incidence of CIN compared with discontinuation (OR 2.06, 95% CI 1.62-2.61, p < 0.001, I2 = 0.0%). A hazard of continuation was marked in a subgroup of older patients or in patients with chronic kidney disease. For drug-naïve patients, however, administration of RAAS blockade before contrast procedures did not reduce the development of CIN significantly (OR 0.52, 95% CI 0.23-1.16, p = 0.108, I2 = 34.2%).

CONCLUSION

Discontinuation of RAAS blockade in chronic users is associated with a significantly lower incidence of CIN, whereas administration of RAAS blockade as a preventive measure for naïve patients did not show a significant effect on the incidence of CIN.

Nonpharmacological strategies to prevent contrast-induced acute kidney injury

Contrast-induced AKI (CI-AKI) has been one of the leading causes for hospital-acquired AKI and is associated with independent risk for adverse clinical outcomes including morbidity and mortality. The aim of this review is to provide a brief summary of the studies that focus on nonpharmacological strategies to prevent CI-AKI, including routine identification of at-risk patients, use of appropriate hydration regimens, withdrawal of nephrotoxic drugs, selection of low-osmolar contrast media or isoosmolar contrast media, and using the minimum volume of contrast media as possible. There is no need to schedule dialysis in relation to injection of contrast media or injection of contrast agent in relation to dialysis program. Hemodialysis cannot protect the poorly functioning kidney against CI-AKI.

Hemodynamic and tubular changes induced by contrast media

The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI.

ACE-I/ARB therapy prior to contrast exposure: what should the clinician do?

Contrast-induced nephropathy (CIN) is now one of the three leading causes of acute kidney injury in the world. A lot is known about the risk factors of CIN, yet it remains a major cause of morbidity, end stage renal disease, prolonged hospital stay, and increased costs as well as a high mortality. Many patients undergoing contrast-based radiological investigations are treated with angiotensin converting inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) for their cardiac and renal benefits and their known mortality benefits. However, controversy exists among clinicians as to whether ACE-Is and ARBs should be continued or discontinued prior to contrast media exposure. In this paper we review the current evidence on ACE-I/ARB therapy for patients undergoing procedures involving use of contrast media and provide recommendations as to whether these drugs should be continued or held prior to contrast exposure.

Mannitol and renal dysfunction after endovascular aortic aneurysm repair procedures: a randomized trial

OBJECTIVE

Endovascular aortic aneurysm repair (EVAR) may result in deterioration of renal function. Mannitol has renovascular and antioxidant properties that could prove beneficial in this respect.

DESIGN

A randomized prospective study.

SETTING

Attikon University Hospital, single institution.

PARTICIPANTS

Eighty-six patients undergoing elective EVAR under regional anesthesia.

METHODS

Patients received hydration alone (controls) or hydration plus mannitol (0.5 g/kg).

MEASUREMENTS AND MAIN RESULTS

Creatinine, serum cystatin-C, urine neutrophil-gelatinase-associated lipocalin (NGAL), albuminuria and serum urea were measured 24 hours and 72 hours after the procedure (baseline NGAL was measured in 19 randomly selected patients). Serum creatinine also was measured at the followup of the patients. Serum creatinine and cystatin-C were lower in the mannitol group at 24 hours postoperatively (creatinine, mannitol [n=43]; 1.07±0.26 [CI95%: 0.99-1.15] v controls [n=43]; 1.20±0.30 [CI95%: 1.11-1.30]), but not at 72 hours (creatinine, mannitol [n=43]; 1.13±0.29 [CI95%: 1.04-1.22] v controls [n=43]; 1.26±0.41 [CI95% 1.15-1.38]). Urine NGAL increased substantially at 24 hours without differences between groups. At followup (controls: 13±7 months; mannitol: 12±7 months), there were no differences between creatinine or creatinine clearance (creatinine: controls [n=28]; 1.15±0.39 [CI95% 1.02-1.29] v mannitol [n=23]; 1.05±0.27 [CI95%: 0.95-1.17]). The overall changes of creatinine and creatinine clearance with time were significant in controls but not in the mannitol group. The classification according to the RIFLE criteria yielded 4 patients at risk for renal injury and 2 with renal injury in the control group and 6 patients at risk with no patients with injury in the mannitol group, but the difference of renal dysfunction between the 2 groups was not statistically significant.

CONCLUSIONS

Mannitol plus hydration during EVAR provides a small but significant benefit for renal function. Future preventive protocols aiming at greater restoration of renal function after EVAR could include mannitol as a useful component.

Left radial access is preferable to right radial access for the diagnostic or interventional coronary procedures: a meta-analysis involving 22 randomized clinical trials and 10287 patients

OBJECTIVE

The transradial approach has been used extensively for both diagnostic and interventional coronary procedures; however, there is no universal consensus hitherto on the optimal choice of radial access from either the left or the right artery. We therefore sought to meta-analyze available randomized clinical trials to compare the left with the right radial access for the diagnostic or interventional coronary procedures.

METHODS AND RESULTS

Four electronic databases including the PubMed, EMBASE, Wanfang, and CNKI were searched up to April 2013. In total, there were 22 qualified randomized trials involving 5317 and 4970 patients assigned to the left and the right radial accesses, respectively. Data were extracted independently by two investigators. Analyses of the full data set indicated significant reductions in fluoroscopy time (seconds) (weighted mean difference; 95% confidence interval; P: -36.18; -53.28 to -18.53; <0.0005) and contrast use (mL) (-2.88; -5.41 to -0.34; 0.026) in patients with the left radial access compared to those with the right radial access, and there was strong evidence of heterogeneity but low probability of publication bias. The failure rate of radial access from the left was relatively lower than that from the right (odds ratio: 0.83; 95% confidence interval: 0.68-1.01; P = 0.064). Further in meta-regression analyses, body mass index was found to be a potential source of heterogeneity for both fluoroscopy time (regression coefficient: 35.85; P = 0.025) and catheter number (regression coefficient: 0.35; P = 0.018).

CONCLUSIONS

Our findings demonstrate that left radial access is preferable to right radial access in terms of fluoroscopy time and contrast use for the diagnostic or interventional coronary procedures. The import of this study lies in its great shock to the concept of convenient radial access from the right artery.