3.1 Patients’ characteristics
Out of 655 patients identified in our department between 2010 and 2021, 246 met Sidney’s criteria for APS. Two hundred and seven patients had a TAPS and were included in the analysis (Figure 1).
Characteristics at diagnosis and during follow-up of the 207 patients with TAPS are summarized in Table 1. The mean age at diagnostic was 53.3 years and 45.9% were male. APS was primary in 161 (77.8%) patients and SLE was present at diagnosis in 14 (6.8%) patients. There were 146 (70.5%) venous thromboembolic primary events and 68 (32.9%) arterial primary events. The APL positivity was single in 133 (64.3%) patients, double in 47 (22.7%) patients and triple in 27 (13%) patients. Twenty-seven (13%) patients were treated with APT only after diagnosis confirmation, 123 (59.4%) with VKA, and 45 (24.2%) with DOACs. Seven (3.4%) patients did not benefit of any antithrombotic drug. Mean follow-up was 5.2 years and median follow-up 3.5 years (Table 1).
During follow-up, 28 (13.5%) recurrent thrombosis occurred (Table 1). Among them, 16 (57.1%) occurred to patients who were treated with VKA, 2 (7.2%) to patients treated with DOACs, 7 (25%) to patients treated with APT only and 3 (10.7%) to patients who had no antithrombotic treatment. Patients with VKA had 7 (43.8%) arterial recurrent thrombosis and 9 (56.3%) recurrent VTE. Patients with DOACs had 2 (100%) recurrent VTE. Patients treated with APT only or without antithrombotic treatment (n = 34) had 6 (60%) recurrent arterial thrombosis and 4 (40%) VTE events. The mean time from diagnosis to recurrence was 3.5 years and median time was 2 years. Death occurred in 12 (5.8%) patients, 7 (3.3%) under VKA, 4 (1.9%) under DOACs, 1 (0.5%) under APT only and none without treatment. Two patients died from hemorrhagic complications (both were in the VKA group) and none from recurrent thrombosis.
3.2 Risk factors for thrombotic recurrence
Risk factors for recurrent thrombosis in multivariate analysis were SLE (HR = 4.27 [1.31 ; 13.92], p = 0.0160), diabetes mellitus (HR = 10.12 [3.37 ; 30.34], p < 0.0001), anticoagulation before the primary thrombotic event (HR = 3.70 [1.29 ; 10.61], p = 0.0147), previously known OAPS (HR = 7.70 [2.70 ; 21.96], p = 0.0001), no treatment after the primary thrombotic event (HR = 3.43 [1.06 ; 11.08], p = 0.0399) and APT alone after the primary thrombotic event (HR = 4.17 [1.53 ; 11.36], p = 0.0052). DOACs and VKA were not associated with recurrent thrombosis (Table 2).
In the survival analysis, recurrent thrombosis were significantly higher in the group without antithrombotic treatment in comparison with those treated with DOACs (HR = 7.65 [1.18 ; 49.60]) (Figure 2). Recurrent thrombosis tended to be higher in the group without antithrombotic treatment as compared to those treated with VKA (HR = 3.88 [0.99 ; 15.27]) (Figure 2).
No difference in the mortality rates were identified between the four treatment groups (Figure 3).
3.3 Clinical and biological characteristics according to initial antithrombotic drugs
Clinical and biological characteristics according to initial oral anticoagulation (VKA versus DOACs (+/- APT)) are provided in Table 3. Patients with VKA were significantly younger and had more arterial thrombosis, LA positivity and triple APL positivity than those treated with DOACs (Table 3). Conversely, patients with DOACs were significantly older and had more venous thrombosis and single APL positivity.
Factors associated with VKA versus DOACs prescription were the presence of LA (OR = 6.97 [1.42 ; 34.10], p < 0.0001), aCL positivity (OR = 3.23 [1.11 ; 9.38], p = 0.0314), aβ2GP1 IgM positivity (OR = 3.59 [1.25 ; 10.31], p = 0.0173), triple APL positivity (OR = 7.90 [1.35 ; 46.21], p = 0.0218) and the absence of primary venous thrombosis (OR = 0.01 [0.00 ; 0.25], p = 0.0036) (Table 4).
3.4 Bleedings
Twenty-seven (13%) bleedings occurred during follow-up. Twenty-two (81.4%) patients were treated with VKA, 3 (11.1%) were treated with DOACs and 2 (7.5%) with APT only. Significantly more bleedings were found in VKA group as compared to DOACs (Table 3).