Abstract：
BACKGROUND: There are currently three strategies for the duration of LMWH lead-in before DOACs in patients with acute PE: one is at least 5 days, the other is at least 3 days, and the last one is less than 3 days. Which one is the best is yet unknown.
METHODS: We divided non-high-risk PE patients into short-LMWH (LMWH <3 days), intermediate-LMWH (LMWH 3-5 days), and long-LMWH (LMWH >5 days) groups, in a 1:1:2 ratio by using propensity score matching. Primary outcomes were a composite of mortality including all-cause and PE-related mortality, VTE recurrence, and major bleeding, as well as each one of them, at 3-month after PE diagnosis.
RESULTS: The short-LMWH group (N = 504) had higher 3-month composite primary outcome (129 [25.6%] vs 67 [13.3%], P < 0.001), all-cause mortality (112 [22.2%] vs 39 [7.7%], P < 0.001), and PE-related mortality (48 [9.5%] vs 17 [3.4%], P < 0.001), than the intermediate-LMWH group (N = 504). The short-LMWH group also had higher 3-month composite primary outcome (129 [25.6%] vs 151 [15.0%], P < 0.001), all-cause mortality (112 [22.2%] vs 90 [8.9%], P < 0.001), and PE-related mortality (48 [9.5%] vs 41 [4.1%], P < 0.001) than the long-LMWH group (N = 1008). The VTE recurrence and major bleeding rates were similar between the short-LMWH and intermediate-LMWH groups, and between the short-LMWH and long-LMWH groups. The intermediate-LMWH and long-LMWH groups had similar 3-month primary outcomes rates in whole or in part with each other.
CONCLUSIONS: For patients with non-high-risk acute PE, the optimal duration of initial LMWH lead-in before switching to DOACs could be 3 to 5 days.
METHODS: We divided non-high-risk PE patients into short-LMWH (LMWH <3 days), intermediate-LMWH (LMWH 3-5 days), and long-LMWH (LMWH >5 days) groups, in a 1:1:2 ratio by using propensity score matching. Primary outcomes were a composite of mortality including all-cause and PE-related mortality, VTE recurrence, and major bleeding, as well as each one of them, at 3-month after PE diagnosis.
RESULTS: The short-LMWH group (N = 504) had higher 3-month composite primary outcome (129 [25.6%] vs 67 [13.3%], P < 0.001), all-cause mortality (112 [22.2%] vs 39 [7.7%], P < 0.001), and PE-related mortality (48 [9.5%] vs 17 [3.4%], P < 0.001), than the intermediate-LMWH group (N = 504). The short-LMWH group also had higher 3-month composite primary outcome (129 [25.6%] vs 151 [15.0%], P < 0.001), all-cause mortality (112 [22.2%] vs 90 [8.9%], P < 0.001), and PE-related mortality (48 [9.5%] vs 41 [4.1%], P < 0.001) than the long-LMWH group (N = 1008). The VTE recurrence and major bleeding rates were similar between the short-LMWH and intermediate-LMWH groups, and between the short-LMWH and long-LMWH groups. The intermediate-LMWH and long-LMWH groups had similar 3-month primary outcomes rates in whole or in part with each other.
CONCLUSIONS: For patients with non-high-risk acute PE, the optimal duration of initial LMWH lead-in before switching to DOACs could be 3 to 5 days.
摘要：
背景：目前在急性PE患者中，DOAC之前LMWH导入的持续时间有三种策略：一种是至少5天，另一个是至少3天,最后一个是不到3天。哪个是最好的还不清楚。
方法：我们将非高危PE患者分为短LMWH（LMWH<3天），中级LMWH（LMWH3-5天），和长LMWH（LMWH>5天）组，通过使用倾向评分匹配，以1:1:2的比例。主要结局是死亡率的复合，包括全因死亡率和PE相关死亡率。VTE复发,大出血,以及他们中的每一个，在PE诊断后3个月。
结果：短LMWH组（N=504）的3个月复合主要结局较高（129[25.6％]vs67[13.3％]，P<0.001)，全因死亡率（112[22.2%]vs39[7.7%]，P<0.001)，和PE相关死亡率（48[9.5%]vs17[3.4%]，P<0.001)，比中间-LMWH基团(N=504)。短LMWH组的3个月复合主要结局也较高（129[25.6％]vs151[15.0％]，P<0.001)，全因死亡率（112[22.2%]vs90[8.9%]，P<0.001)，与PE相关的死亡率（48[9.5%]vs41[4.1%]，P<0.001)比长LMWH组(N=1008)。短LMWH组和中间LMWH组的VTE复发率和大出血率相似，以及短LMWH和长LMWH组之间。中间LMWH组和长LMWH组具有相似的3个月主要结局率。
结论：对于非高危急性PE患者，在切换到DOAC之前,初始LMWH导入的最佳持续时间可以是3~5天.
方法：我们将非高危PE患者分为短LMWH（LMWH<3天），中级LMWH（LMWH3-5天），和长LMWH（LMWH>5天）组，通过使用倾向评分匹配，以1:1:2的比例。主要结局是死亡率的复合，包括全因死亡率和PE相关死亡率。VTE复发,大出血,以及他们中的每一个，在PE诊断后3个月。
结果：短LMWH组（N=504）的3个月复合主要结局较高（129[25.6％]vs67[13.3％]，P<0.001)，全因死亡率（112[22.2%]vs39[7.7%]，P<0.001)，和PE相关死亡率（48[9.5%]vs17[3.4%]，P<0.001)，比中间-LMWH基团(N=504)。短LMWH组的3个月复合主要结局也较高（129[25.6％]vs151[15.0％]，P<0.001)，全因死亡率（112[22.2%]vs90[8.9%]，P<0.001)，与PE相关的死亡率（48[9.5%]vs41[4.1%]，P<0.001)比长LMWH组(N=1008)。短LMWH组和中间LMWH组的VTE复发率和大出血率相似，以及短LMWH和长LMWH组之间。中间LMWH组和长LMWH组具有相似的3个月主要结局率。
结论：对于非高危急性PE患者，在切换到DOAC之前,初始LMWH导入的最佳持续时间可以是3~5天.
