Adjuvant effect of green tea intake on treatment of patients with acute venous thromboembolism.

Abstract

Background: Although there have been reports that green tea intake has thromboprophylactic effect, it was still unknown whether it had adjuvant effect on the basis of conventional anticoagulation for patients diagnosed with venous thromboembolism (VTE).

Methods: VTE patients were retrospectively classified into green tea group and no green tea group in a 1:1 ratio using propensity score matching, based on whether they drank green tea during the 3 months' period after VTE diagnosis. Primary outcomes were VTE recurrence at 3 months after VTE diagnosis and VTE-related death during 3 months after VTE diagnosis. Secondary outcomes were all-cause death and major bleeding during 3 months after VTE diagnosis. The primary and secondary outcomes were compared between the green tea and no green tea groups, in all patients, PE patients, and patients with cancer-associated VTE, respectively.

Results: The VTE recurrence at 3-month after VTE diagnosis occurred less in the green tea group (N = 1102) than in the no green tea group (N = 1102) (19 [1.7%] vs 55 [5.0%], P < 0.001). The VTE-related mortality during 3 months after VTE diagnosis occurred similarly between the two groups (13 [1.2%] vs 21 [1.9%], P = 0.187). The all-cause mortality (82 [7.4%] vs 78 [7.1%], P = 0.682) and major bleeding (55 [5.0%] vs 40 [3.6%], P = 0.142) during 3 months after VTE diagnosis both occurred similarly between the two groups. The results of VTE recurrence analysis in PE and cancer-associated VTE subgroups were both consistent with the main findings.

Conclusions: Green tea intake on the basis of conventional anticoagulation can lead to a lower short-term VTE recurrence rate without safety concern, compared with isolated conventional anticoagulation.