Surgery in cardiovascular disease
THERAPEUTIC Guidelines: Cardiovascular version 5 includes new material about surgery in patients with cardiovascular disease.
Antibiotic prophylaxis is not required for patients with implantable cardioverter-defibrillators (ICDs) or permanent pacemakers (PPMs) undergoing surgery.
Surgical diathermy may affect these devices. Diathermy signals may be misinterpreted as an arrhythmia by an ICD. To avoid inappropriate shocks during surgery, implantable defibrillators should be programmed ‘off’ before surgery, and reprogrammed ‘on’ immediately after.
Occasionally PPMs are temporarily inhibited by diathermy. This is only of consequence if a patient is totally pacemaker-dependent, and in this situation the PPM can be reprogrammed to provide continuous pacing.
Anticoagulant drugs usually require temporary discontinuation to reduce the risk of bleeding. Warfarin should be omitted for four doses prior to surgery. In most cases, warfarin can be recommenced on the day of surgery or within the next few days. This approach leads to only a few days without an anticoagulant effect.
In most cases of atrial fibrillation, there is no need for interim heparin while the INR is subtherapeutic. In patients with mechanical cardiac valve replacement, heparin is usually required but specialist advice should be sought.
In the case of recently diagnosed venous thromboembolism, non-urgent surgery should be deferred, otherwise use of heparin and/or vena caval filters should be considered.
These recommendations should be balanced by the surgical bleeding risk. Surgery with a high risk of bleeding may require a longer period of discontinuation of anticoagulation, and consultation with the surgeon involved is necessary.