Perioperative bleeding and thromboembolic risk during non-cardiac surgery in patients with mechanical prosthetic heart valves: an institutional review.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to determine the risk of thromboembolic and bleeding complications in patients with mechanical heart valve prostheses who underwent non-cardiac surgery under different regimens of perioperative anticoagulation. Data were analyzed on the basis of surgery type and underlying disease.

METHODS

A series of 235 patients (mean age 63 +/- 4.5 years) with one or two mechanical heart valves underwent subsequent non-cardiac surgery comprising abdominal, vascular and thoracic, orthopedic, urologic, neurosurgery, ENT, plastic and reconstructive, and gynecologic operations. Mean interval between heart valve replacement and non-cardiac surgery was 3.9 +/- 3.3 years. Perioperative oral anticoagulation was managed by discontinuation of oral anticoagulation and intravenous heparin administration; or by discontinuation and early postoperative re-institution of oral anticoagulation without intravenous heparin; or by no withdrawal of oral anticoagulation. Patients with bioprostheses were excluded.

RESULTS

Overall hospital mortality during non-cardiac surgery was 2.9%. Thromboembolic events included cerebral embolism with transient deficit (n = 3), residual defect (n = 1) and irreversible defect (n = 1), as well as peripheral embolism (n = 11). Hemorrhagic complications included wound hematoma (n = 10) and increased postoperative bleeding (n = 8) with re-exploration in five patients. Thromboembolic complications occurred most often in patients with prosthetic mitral valve and atrial fibrillation; the lowest risk was in patients with sinus rhythm after aortic valve replacement. Most complications occurred after discharge and in patients with surgery for malignancy, within 10 days of instituting oral anticoagulation, and despite a therapeutic INR value.

CONCLUSIONS

Minor surgical procedures can be performed safely without discontinuing anticoagulation. When major non-cardiac surgery is planned, discontinuing oral anticoagulation and starting perioperative intravenous heparin minimizes bleeding and thromboembolic risks. Thromboembolic complications may occur within one month of surgery, despite adequate oral anticoagulation, though permanent morbidity is low.