High Rate of Deep-Vein Thrombosis in Asia after Major Orthopedic Surgery: The AIDA Study Final Results.

Background: The incidence of post-surgical venous thromboembolism is thought to be low in Asian populations and routine thromboprophylaxis is not implemented.

Objective: In this large multinational, multiethnic study, we evaluated the incidence of deep-vein thrombosis (DVT) patients undergoing major orthopedic surgery of the lower limbs.

Methods: We performed a prospective epidemiological study in 19 centers across Asia (China, Indonesia, South Korea, Malaysia, Philippines, Taiwan and Thailand) in patients undergoing elective total hip replacement (THR), total knee replacement (TKR) or hip fracture surgery (HFS) not receiving pharmacological thromboprophylaxis. The primary endpoint was the rate of DVT of the lower limbs objectively documented by mandatory bilateral ascending venography performed 6 to 10 days after surgery and evaluated by a blinded central adjudication committee.

Results: Overall, 407 Asian patients (20–99 years) undergoing THR (n=175), TKR (n=136) or HFS (n= 96) were recruited in 19 centres. 72.5% of the enrolled patients had adequate venograms. Total DVT was diagnosed in 121 of 295 evaluable patients (41.0%, [95% confidence interval: 35.4–46.7]). Proximal DVT was found in 30 patients (10.2% [7.0–14.2]). Total DVT and proximal DVT rates were the highest in TKR patients (58.1% and 17.1%, respectively), followed by HFS patients (42.0% and 7.2%, respectively), then THR patients (25.6% and 5.8%, respectively). DVT was more frequent in female patients aged at least 65 years. By-country analysis showed that the highest DVT rate was observed in Indonesia (78.6%) and the lowest in China (24.3%). By ethnic group, the lowest DVT rate was observed in Koreans (29.8%), while similar results were found in Chinese (45.0%) and in other non-Korean non-Chinese (46.3%) ethnic groups. Pulmonary embolism was clinically suspected in 10 of 407 patients (2.5%) and objectively confirmed in two patients (0.5%).

Conclusions: Venographically detected thrombosis is well recognized as an appropriate surrogate for symptomatic outcomes and is the basis for the recommendation for routine prophylaxis in Western patients. The high rate of venographic thrombosis in Asian patients is similar to that observed in patients in Western countries. Thrombosis prophylaxis should therefore be considered in Asian patients undergoing major orthopedic procedures.