A retrospective observational study of the use of gastroprotection for patients on dual antiplatelet therapy in an acute trust in England
Authors: Wong E W , Bastian L , Wilcock M 
Published: April 2022

Abstract

Introduction
Dual antiplatelet therapy (DAPT), a combination of aspirin and either clopidogrel, prasugrel or ticagrelor, is recommended for secondary prevention of ischaemic events (heart attack and stroke) in people with coronary artery disease. Patients taking DAPT may be at high gastrointestinal (GI) bleed risk if other factors (including advanced age, or concomitant use of medicines that are known to increase the risk of GI bleeds) are present. Such patients should be considered for gastroprotection e.g. a proton pump inhibitor (PPI) or H2 receptor antagonist.

Aim
To assess whether gastroprotection was prescribed for inpatients taking DAPT in a 750-bed acute hospital in England.

Methods
This was a retrospective analysis of existing data. Patient episodes involving prescription of DAPT upon discharge between April 2020 and April 2021 were extracted from the e-prescribing system (WellSky). Electronic records of the identified patient episodes were searched for co-prescription of either PPI or H2 antagonist. We also ascertained if patients on DAPT should have received gastro-protection using age 71 and over, and concomitant drugs as separate risk factors.

Results
Over this 13-month period there were 1693 patient episodes (mean age 72 years, 63% male) when DAPT was prescribed at discharge, of which gastroprotection was also prescribed in 1210 (71%). Of the 483 episodes when gastroprotection was not prescribed, 223 (46%) met the criterion of age as a risk factor for gastroprotection. There were a further 20 episodes of patients aged under 71 years not on gastroprotection but receiving an SSRI, NSAID, prednisolone, nicorandil or an anticoagulant.

Conclusion
We identified that gastroprotection was potentially missing in 243 (14%) of the total DAPT patient episodes. Though there is evidence for the use of PPIs reducing the risk of GI bleeding in patients treated with DAPT after percutaneous coronary intervention or acute coronary syndrome (1), studies have reported that gastroprotection has been missed in the at risk group (2). When considering newly initiated gastroprotection, various factors are considered e.g. any possible interaction with a PPI if one of the antiplatelets is clopidogrel. In addition, PPIs have adverse effects such as low sodium / magnesium, and this may be a reason for consideration of a H2 antagonist. Further work is required to make our prescribers and pharmacy team aware of the importance of considering gastroprotection for this patient cohort. The strength of this study is the extraction of data from our electronic prescribing system for a large cohort of patients prescribed specified antiplatelet medication. Our study has some potential limitations. First, it was conducted in a single centre in England; this might restrict the generalisability of our findings. Second, the retrospective nature of this study may introduce bias or other uncertainties. Third, we did not ascertain the indication for DAPT nor if patients came in on these drugs as opposed to being started during their admission. Fourth, we did not check risk factors for gastroprotection other than age and selected concomitantly prescribed drugs. Finally, we did not check if those not prescribed gastroprotection had significant contraindications other than electrolyte abnormalities.

References
(1) Guo H, Ye Z, Huang R. Clinical outcomes of concomitant use of proton pump inhibitors and dual antiplatelet therapy: a systematic review and meta-analysis. Front Pharmacol. 2021 Aug 2;12:694698.
(2) Sehested TSG, Carlson N, Hansen PW, Gerds TA, Charlot MG, Torp-Pedersen C, et al. Reduced risk of gastrointestinal bleeding associated with proton pump inhibitor therapy in patients treated with dual antiplatelet therapy after myocardial infarction. Eur Heart J. 2019;40(24):1963–70.