Chronic utilization of agents acting on the renin-angiotensin system and intraoperative arterial pressure

There has been concern that taking agents acting on the renin-angiotensin system (ARAS) in surgery day, may predispose patients to higher risk of intraoperative hypotension during surgery. Therefore, the European Society of Cardiology and the European Society of Anesthesiology recommend transient discontinuation of ARAS before non-cardiac surgery in hypertensive patients. As the existent evidence is limited, this recommendation remains debated.

The objectives of the study were to evaluate the effects of ARAS chronic utilization on intraoperative arterial pressure.

This historical cohort consisted in recruitment of surgery patients over 12 months, at "Cova da Beira Hospital Center". The data were gathered from an interview to the patient and by postoperative review of the medical record.

The study consisted of 756 patients. Of those, 589 did not take antihypertensive medication and 176 were taking chronic ARAS. In univariate analysis, only the appearance of intraoperative hypertension was significantly greater in ARAS group. In logistic regression analysis, age, diabetes mellitus and taking ARAS were the only significant risk factors to the appearance of intraoperative hypertension. In ARAS group, 123 patients stopped the ARA before surgery and 53 continued it until the surgery day. The frequency of the two outcomes did not differ between the two groups.

In our study hypotension episodes during non-cardiac surgery could not be attributed to ARAS chronic utilization and taking ARAS on surgery morning when compared with withdrawal was not associated with hypotension episodes.