What drugs should be stopped before cardiac surgery and how long?

1. Beta blockers

A sudden stop can result in rebound hypertension, tachycardia and recurrent myocardial ischemia.
Action: To be continued up to and including morning of surgery and restarted immediately afterwards or eventually substituted with short acting beta blockers (eg. propranolol, metoprolol, esmolol). Cardiac pacing may be necessary during the immediate postoperative period.
Perioperative use can prevent postoperative myocardial ischemic events (1). 

2. ACE inhibitors and angiotensin receptor blockers

Continued use can result in peroperative hemodynamic instability (2).
Action: Protocol depends on indications
• for hypertension : continue up to the day of surgery.
• for heart failure : discontinue on day of surgery, especially if baseline blood pressure is low (3).

3. Calcium channel blockers

Anti-ischemic properties despite a theoretical risk of increased bleeding (4).
Action: To be continued up to and including day of surgery, except in the case of poor hemodynamics (hypotension or arrhythmia). Can be substituted with short acting calcium channel blockers (e.g. Diltiazem).

4. Nitrates

Action: To be continued up to and including day of surgery. Can be administered IV or transdermally, particularly if therapy cannot be interrupted e.g. frank ischemia (5).

5. Alpha 2 agonists

Abrupt withdrawal can cause extreme hypertension and myocardial ischemia.
Action: To be continued up to and including day of surgery. Substitution by transdermal clonidine or exceptionally IV methyl dopa.

6. Aspirin, Clopidogrel

Use may be associated with increased bleeding due to platelet dysfunction.
Action: To be stopped 5-7 days before surgery if possible. Transfusion of fresh platelets if bleeding is an issue postoperatively (6).
Restart in ward at discretion of treating physician.

7. Oral anticoagulants (Warfarin)

Action: Should be stopped 4 days prior to surgery, and substituted by IV heparin according to INR level.

8. Diuretics

Risk of hypovolemia and hypotension from continued use. Electrolyte disturbance is often easy to correct with cardioplulmonary bypass (7).
Action: To be continued up to day of surgery. Substitution by parenteral forms if necessary in postoperative period.

9. Digoxin and Antiarrhythmics

Action: To be continued up to day of surgery. Substitution by intravenous forms if necessary.

10. Statins

Action: To be continued up to and including day of surgery.
Shown to have a beneficial effect on outcome, especially after coronary artery bypass grafting thus merit to be continued in the perioperative period (8,9).

11. Oral hypoglycemics/ Insulin

Action: Patients with type II diabetes mellitus should stop oral hypoglycemics several days prior to surgery (especially metformin which is known to contribute to postoperative lactic acidosis). Patients on Insulin (SC or IV) should omit their morning dose. Peroperative blood glucose monitoring determines further insulin needs (10).

The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.