Chinese patients with left ventricular thrombus: NOACs may be an alternative to warfarin

Although warfarin is the guideline-recommended anticoagulant for LVT, the growing popularity of NOACs has led to increasing interest in their potential as an alternative in LVT management. [Eur Heart J 2023;44:3720-3826; Stroke 2021;52:e364-e467; J Am Coll Cardiol 2019;73:2007-2009] “This study aimed at comparing the efficacy and safety of NOACs vs warfarin for managing LVT,” the researchers wrote. [Hong Kong Med J 2024;30:10-15]

The researchers retrieved data from 43 Chinese adult patients (mean age, 61 years; male, 86.0 percent) with LVT confirmed by echocardiography at Prince of Wales Hospital in Hong Kong between January 2011 and January 2020. Treatment with warfarin or NOACs was based on physicians’ choice, and anticoagulant therapy was only discontinued upon resolution of LVT.

In the study cohort, 28 patients were warfarin users while 15 patients were NOAC users (apixaban, n=10; dabigatran, n=4; rivaroxaban; n=1). Baseline characteristics were generally balanced, although a higher proportion of NOAC users had diabetes mellitus (DM; 66.7 percent vs 14.3 percent; p=0.001) and atrial fibrillation (AF) or flutter (26.7 percent vs 3.6 percent; p=0.043) vs warfarin users. The mean follow-up duration was 20 months and 22 months for the warfarin and NOAC users, respectively. Among 34 patients who completed 1-year follow-up, nine had discontinued anticoagulant therapy.

During the study period, 14 deaths were reported, with 12 occurring in the warfarin group (42.9 percent) and two in the NOAC group (13.3 percent). Cox regression analysis showed a tendency towards lower mortality risk with NOACs vs warfarin (hazard ratio [HR], 0.285; 95 percent confidence interval [CI], 0.064–1.275; p=0.101). This trend remained after adjusting for DM and AF or flutter (HR, 0.184; 95 percent CI, 0.032–1.059; p=0.058).

Net adverse clinical events (NACEs; ie, ischaemic stroke, intracranial haemorrhage, systemic thromboembolism excluding cerebral embolism, fatal bleeding, major nonfatal bleeding) occurred in 13 patients in the warfarin group (46.4 percent) vs one patient in the NOAC group (6.7 percent). The risk of NACEs was significantly lower among NOAC users vs warfarin users (HR, 0.124; 95 percent CI, 0.016–0.952; p=0.045) in Cox regression analysis. The results remained statistically significant after adjusting for DM and AF or flutter (HR, 0.111; 95 percent CI, 0.012–0.994; p=0.049).

The reduced NACE risk with NOACs vs warfarin was likely driven by tendencies towards reduced rates of ischaemic stroke (17.9 percent [n=5] vs 0 percent) and nonfatal major bleeding (14.3 percent [n=4] vs 0 percent).

“The risk of bleeding was substantially lower in Asians vs non-Asians, indicating a potential need for different clinical practice recommendations for these populations,” the researchers suggested. [Thromb Res 2018;166:37-42]

The study also showed similar rates of cumulative mortality and NACEs between patients who discontinued anticoagulant therapy by 1 year and those who continued treatment. “Further studies are warranted to explore the effect of anticoagulant discontinuation by 1 year in patients with LVT resolution,” added the researchers. [Hong Kong Med J 2024;30:10-15]