Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease (CLARITY): statistical analysis plan for a randomised controlled Bayesian adaptive sample size trial

The CLARITY trial (Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease) is a two-arm, multi-centre, randomised controlled trial being run in India and Australia that investigates the effectiveness of angiotensin receptor blockers in addition to standard care compared to placebo (in Indian sites) with standard care in reducing the duration and severity of lung failure in patients with COVID-19. The trial was designed as a Bayesian adaptive sample size trial with regular planned analyses where pre-specified decision rules will be assessed to determine whether the trial should be stopped due to sufficient evidence of treatment effectiveness or futility. Here, we describe the statistical analysis plan for the trial and define the pre-specified decision rules, including those that could lead to the trial being halted. The primary outcome is clinical status on a 7-point ordinal scale adapted from the WHO Clinical Progression scale assessed at day 14. The primary analysis will follow the intention-to-treat principle. A Bayesian adaptive trial design was selected because there is considerable uncertainty about the extent of potential benefit of this treatment.

Trial registration

ClinicalTrials.gov NCT04394117. Registered on 19 May 2020Clinical Trial Registry of India CTRI/2020/07/026831

Version and revisions

Version 1.0. No revisions.

Effects of canagliflozin on hyperkalaemia and serum potassium in people with diabetes and chronic kidney disease: insights from the CREDENCE trial

Background

Hyperkalaemia is a common complication of type 2 diabetes mellitus (T2DM) and limits the optimal use of agents that block the renin-angiotensin aldosterone system (RAAS), particularly in patients with chronic kidney disease (CKD). In patients with CKD, sodium glucose cotransporter 2 (SGLT2) inhibitors provide cardiorenal protection, but whether they affect the risk of hyperkalaemia remains uncertain.

Purpose

We sought to assess the effect of canagliflozin on hyperkalaemia and other potassium-related outcomes in people with T2DM and CKD by conducting a post-hoc analysis of the CREDENCE trial.

Methods

The CREDENCE trial randomized 4401 participants with T2DM and CKD to the SGLT2 inhibitor canagliflozin or matching placebo. In this post-hoc analysis using an intention-to-treat approach, we assessed the effect of canagliflozin on a composite outcome of time to either investigator-reported hyperkalaemia or the initiation of potassium binders. We also analysed effects on central laboratory-determined hyper- and hypokalaemia (serum potassium ≥6.0 and <3.5 mmol/L, respectively) and change in serum potassium.

Results

At baseline the mean serum potassium in canagliflozin and placebo arms was 4.5 mmol/L; 4395 (99.9%) participants were receiving renin angiotensin system blockade. Canagliflozin reduced the risk of investigator-reported hyperkalaemia or initiation of potassium binders (HR 0.78, 95% CI 0.64–0.95, p=0.014; Figure 1). The incidence of laboratory-determined hyperkalaemia was similarly reduced (HR 0.77, 95% CI 0.61–0.98, p=0.031; Figure 2); the risk of hypokalaemia (HR 0.92, 95% CI 0.71–1.20, p=0.53) was not increased. Mean serum potassium over time with canagliflozin was similar to that of placebo.

Conclusion

Among patients treated with RAAS inhibitors, SGLT2 inhibition with canagliflozin may reduce the risk of hyperkalaemia in people with T2DM and CKD without increasing the risk of hypokalaemia.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Independent predictors of heart failure in patients with type 2 diabetes and chronic kidney disease: modeling from the CREDENCE trial

Background

SGLT2 inhibitors have been shown to reduce hospitalization for heart failure (HHF). We sought to determine independent baseline predictors for HHF specifically in a population with type 2 diabetes and chronic kidney disease (CKD).

Methods

CREDENCE randomized 4401 participants with type 2 diabetes and CKD to canagliflozin 100 mg versus placebo. We evaluated the baseline clinical and demographic factors using multivariate regression modeling to identify the independent predictors of HHF.

Results

Overall, 230 participants (89 canagliflozin; 141 placebo) had at least 1 HHF event. Canagliflozin reduced the incidence of HHF compared with placebo (4.0% vs 6.4%; HR 0.61; 95% CI 0.47–0.80). Participants with HHF events postrandomization were older (65.8 vs 62.9 y), and had a longer duration of diabetes (17.4 vs 15.7 y), higher prevalence of prior HF (30.4% vs 14.0%), higher urinary albumin:creatinine ratio (1347 vs 904 mg/g), lower estimated glomerular filtration rate (51.5 vs 56.4 mL/min/1.73m2), and higher prevalence of prior cardiovascular disease (65.7% vs 49.6%) compared to those without HHF. Independent predictors of HHF are shown in the Table.

Conclusions

HHF is common in patients with type 2 diabetes and CKD. Canagliflozin reduces HHF by 39% compared with placebo. Higher urinary albumin:creatinine ratio was the most potent predictor of HHF and should be part of patient risk assessment.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Janssen Research & Development, LLC

Prediction of 10-year vascular risk in patients with diabetes: the AD-ON risk score

AIMS

To formulate a combined cardiovascular risk score in diabetes that could be useful both to physicians and healthcare funders.

METHODS

Data were derived from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation Observational (ADVANCE-ON) study, a randomized controlled trial (mean duration 5 years) with a post-randomization follow-up (mean 4.9 years), that included 11 140 high-risk patients with diabetes. The outcome analysed was the occurrence of either fatal or non-fatal macrovascular or renal disease. A Cox regression model was used to determine weightings in the risk score. The resultant score was recalibrated to each of three major global regions, as covered by the ADVANCE-ON study.

RESULTS

Over a median of 9.9 years, 1145 patients experienced at least one component of the combined outcome event. The resultant score, the AD-ON risk score, incorporated 13 demographic or clinical variables. Its discrimination was modest [c-statistic = 0.668 (95% confidence interval 0.651, 0.685)] but its calibration was excellent (predicted and observed risks coincided well, within disparate global regions). In terms of the integrated discrimination improvement index, its performance was marginally superior, over a 10-year risk horizon, to existing risk scores in clinical use, from a restricted version of the same data, for macrovascular and renal disease separately.

CONCLUSIONS

The AD-ON risk score has advantages over the existing vascular risk scores in diabetes that used data from the original ADVANCE trial, which treat macrovascular and renal diseases separately. These advantages include its simplicity of use and global application.

Omeprazole-induced interstitial nephritis

Acute renal impairment secondary to interstitial nephritis is a rare complication of omeprazole. We describe a 50-year-old woman who took 20 mg omeprazole twice daily for endoscopically proved ulcerative esophagitis. At the same time, Duke's C colonic cancer was diagnosed and completely resected. Five fluorouracil/folinic acid adjuvant chemotherapy was tolerated without diarrhea or mouth ulceration. Renal function was normal before her first monthly cycle but markedly deteriorated immediately before the second cycle was due. The patient was symptomatic with lethargy, nausea, and mild vomiting, but she was clinically normotensive and only mildly dehydrated. Her serum creatinine concentration increased despite prolonged intravenous hydration, peaking at 4.4 mg/dl 1 week later. Results of a renal ultrasound were normal, and urinary microscopic findings were unremarkable. Renal biopsy showed interstitial nephritis, and renal function improved on cessation of omeprazole, eventually returning to normal. We describe the 12 cases of omeprazole-induced interstitial nephritis reported previously.