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Serum creatinine elevation after renin-angiotensin system blockade and long term cardiorenal risks: cohort study

BMJ 2017; 356 doi: https://doi.org/10.1136/bmj.j791 (Published 09 March 2017) Cite this as: BMJ 2017;356:j791

Re: Serum creatinine elevation after renin-angiotensin system blockade and long term cardiorenal risks: cohort study

There is a critical issue in this paper which limits its value and leads to likely incorrect conclusions - simply put, the lack of non-treated comparators means the results cannot exclude potential outcome benefits relative to no RAS blockade irrespective of serum creatinine elevations in treated patients. Indeed, randomised trial evidence suggests patients with such elevations do also benefit. Hence, observational data cannot be used for these types of analyses (many treatments might lead to apparent adverse elevations in one or another risk factor but the net effect of the treatment could still be positive relative to no treatment) and thus one must refer to RCT evidence.

Competing interests: No competing interests

19 May 2017
Naveed Sattar
Professor of Metabolic Medicine
University of Glasgow
126 University place