1
|
Sandilands EA, Rees JM, Raja K, Dhaun N, Morrison EE, Hickson K, Wraight J, Gray T, Briody L, Cameron S, Thompson AP, Johnston NR, Uren N, Goddard J, Treweeke A, Rushworth G, Webb DJ, Bateman DN, Norrie J, Megson IL, Eddleston M. Acetylcysteine has No Mechanistic Effect in Patients at Risk of Contrast-Induced Nephropathy - A Failure of Academic Clinical Science. Clin Pharmacol Ther 2022; 111:1222-1238. [PMID: 35098531 PMCID: PMC9306485 DOI: 10.1002/cpt.2541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/10/2022] [Indexed: 11/25/2022]
Abstract
Contrast‐induced nephropathy (CIN) is a major complication of imaging in patients with chronic kidney disease (CKD). The publication of an academic randomized controlled trial (RCT; n = 83) reporting oral (N)‐acetylcysteine (NAC) to reduce CIN led to > 70 clinical trials, 23 systematic reviews, and 2 large RCTs showing no benefit. However, no mechanistic studies were conducted to determine how NAC might work; proposed mechanisms included renal artery vasodilatation and antioxidant boosting. We evaluated the proposed mechanisms of NAC action in participants with healthy and diseased kidneys. Four substudies were performed. Two randomized, double‐blind, placebo‐controlled, three‐period crossover studies (n = 8) assessed the effect of oral and intravenous (i.v.) NAC in healthy kidneys in the presence/absence of iso‐osmolar contrast (iodixanol). A third crossover study in patients with CKD stage III (CKD3) (n = 8) assessed the effect of oral and i.v. NAC without contrast. A three‐arm randomized, double‐blind, placebo‐controlled parallel‐group study, recruiting patients with CKD3 (n = 66) undergoing coronary angiography, assessed the effect of oral and i.v. NAC in the presence of contrast. We recorded systemic (blood pressure and heart rate) and renal (renal blood flow (RBF) and glomerular filtration rate (GFR)) hemodynamics, and antioxidant status, plus biomarkers of renal injury in patients with CKD3 undergoing angiography. Primary outcome for all studies was RBF over 8 hours after the start of i.v. NAC/placebo. NAC at doses used in previous trials of renal prophylaxis was essentially undetectable in plasma after oral administration. In healthy volunteers, i.v. NAC, but not oral NAC, increased blood pressure (mean area under the curve (AUC) mean arterial pressure (MAP): mean difference 29 h⋅mmHg, P = 0.019 vs. placebo), heart rate (28 h⋅bpm, P < 0.001), and RBF (714 h⋅mL/min, 8.0% increase, P = 0.006). Renal vasodilatation also occurred in the presence of contrast (RBF 917 h⋅mL/min, 12% increase, P = 0.005). In patients with CKD3 without contrast, only a rise in heart rate (34 h⋅bpm, P = 0.010) and RBF (288 h⋅mL/min, 6.0% increase, P = 0.001) occurred with i.v. NAC, with no significant effect on blood pressure (MAP rise 26 h⋅mmHg, P = 0.156). Oral NAC showed no effect. In patients with CKD3 receiving contrast, i.v. NAC increased blood pressure (MAP rise 52 h⋅mmHg, P = 0.008) but had no effect on RBF (151 h⋅mL/min, 3.0% increase, P = 0.470), GFR (29 h⋅mL/min/1.73m², P = 0.122), or markers of renal injury. Neither i.v. nor oral NAC affected plasma antioxidant status. We found oral NAC to be poorly absorbed and have no reno‐protective effects. Intravenous, not oral, NAC caused renal artery vasodilatation in healthy volunteers but offered no protection to patients with CKD3 at risk of CIN. These findings emphasize the importance of mechanistic clinical studies before progressing to RCTs for novel interventions. Thousands were recruited to academic clinical trials without the necessary mechanistic studies being performed to confirm the approach had any chance of working.
Collapse
Affiliation(s)
- Euan A Sandilands
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Jessica Mb Rees
- Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - Khuram Raja
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Neeraj Dhaun
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Department of Renal Medicine, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Emma E Morrison
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Kirsty Hickson
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Jonathan Wraight
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Tanya Gray
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Lesley Briody
- Wellcome Trust Clinical Research Facility, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Sharon Cameron
- Wellcome Trust Clinical Research Facility, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Adrian P Thompson
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Neil R Johnston
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Neal Uren
- Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Jane Goddard
- Department of Renal Medicine, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Andy Treweeke
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Gordon Rushworth
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - David J Webb
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - D Nicholas Bateman
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - John Norrie
- Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - Ian L Megson
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Michael Eddleston
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| |
Collapse
|
2
|
Treweeke A, Hall J, Lambie S, Leslie SJ, Megson IL, MacRury SM. Preliminary study of hypoxia-related cardiovascular mediator-markers in patients with end-stage renal disease with and without diabetes and the effects of haemodialysis. PLoS One 2017; 12:e0178171. [PMID: 28542479 PMCID: PMC5441650 DOI: 10.1371/journal.pone.0178171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/08/2017] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Evidence points to activation of pro-inflammatory and pro-thrombotic stimuli during the haemodialysis process in end-stage renal disease (ESRD) with potential to predispose to cardiovascular events. Diabetes is associated with a higher incidence of cardiovascular disease in haemodialysis patients. We tested the hypothesis that a range of mediators and markers that modulate cardiovascular risk are elevated in haemodialysis patients with diabetes compared to those without. METHODS Men and women with diabetes (n = 6) and without diabetes (n = 6) aged 18-90 years receiving haemodialysis were recruited. Blood samples were collected and analysed pre- and post-haemodialysis sessions for (platelet-monocyte conjugates (PMC), oxidised LDL (Ox-LDL), endothelin 1 (ET-1) and vascular endothelial growth factor (VEGF-A). RESULTS PMC levels significantly increased after haemodialysis in both groups (diabetes p = 0.047; non-diabetes p = 0.005). Baseline VEGF-A was significantly higher in people with diabetes (p = 0.009) and post-dialysis levels were significantly reduced in both groups (P = 0.002). Ox-LDL and CRP concentrations were not significantly different between groups nor affected in either group post-dialysis. Similarly, ET-1 concentrations were comparable in all patients at baseline, with no change post-dialysis in either group. CONCLUSIONS In this pilot study, we have confirmed that circulating PMCs are increased following dialysis irrespective of diabetes status. This is likely to be a mechanistic process and offers a potential explanation for high rates of vascular events associated with haemodialysis. The higher VEGF-A concentrations between patients with and without diabetes is a previously unreported finding in diabetic ESRD. Further research is merited to establish whether VEGF-A is a marker or mediator (or both) of cardiovascular risk in haemodialysis.
Collapse
Affiliation(s)
- A. Treweeke
- Division of Health Research, University of the Highlands and Islands, Inverness, Scotland
| | - J. Hall
- Division of Health Research, University of the Highlands and Islands, Inverness, Scotland
| | - S. Lambie
- Department of Medicine, Raigmore Hospital, Inverness, Scotland
| | - S. J. Leslie
- Division of Health Research, University of the Highlands and Islands, Inverness, Scotland
- Department of Medicine, Raigmore Hospital, Inverness, Scotland
| | - I. L. Megson
- Division of Health Research, University of the Highlands and Islands, Inverness, Scotland
| | - S. M. MacRury
- Division of Health Research, University of the Highlands and Islands, Inverness, Scotland
- Department of Medicine, Raigmore Hospital, Inverness, Scotland
| |
Collapse
|