Duration of warfarin use may influence postoperative MACE
Short-term use (<30 days) of the anticoagulant warfarin following bioprosthetic aortic valve replacement (AVR) reduced the incidence of major adverse cardiovascular events (MACE) but not the risk of bleeding and re-operation, while long-term warfarin use (31–90 days) resulted in a higher incidence of MACE and reoperation, according to data presented at the Asian Pacific Society of Cardiology Congress (APSC 2017) held in Singapore.
Using data from Taiwan’s National Health Insurance Database (NHIRD) between 2001 and 2010, researchers evaluated 1,007 patients (63 percent male, mean age 66.7 years) who had undergone bioprosthetic AVR. Of these, 718 were on warfarin for ≥3 months, while 289 did not receive warfarin (nonusers). [APSC 2017, abstract P28]
Compared with nonusers, patients receiving warfarin were younger (66.1 years vs 68.4 years) and had a higher incidence of cardiovascular comorbidities such as hypertension (n=306 vs 138), coronary artery disease (n=187 vs 80), and heart failure (n=120 vs 57).
Short-term warfarin users had a decreased risk of MACE (adjusted hazard ratio [adjHR], 0.53; p=0.0005), but there was no difference in terms of bleeding (adjHR, 1.02; p=0.96) and risk of re-operation (adjHR, 0.71; p=0.60) compared with nonusers.
Conversely, long-term warfarin users had an increased risk of MACE compared with short-term users (adjHR, 2.21; p=0.0005), as well as a higher risk of reoperation (adjHR, 3.88; p=0.04).
A higher risk of postoperative MACE was observed in older patients (adjHR, 1.91; p=0.06 in patients aged 65–74 years and adjHR, 1.75; p=0.11 in patients aged ≥75 years) and those who had atrial fibrillation (adjHR, 1.88; p=0.04), hypertension (adjHR, 1.37; p=0.08), and renal comorbidities (eg, chronic kidney disease, end-stage renal disease; adjHR, 2.15; p=0.002).
Overall, the results reveal the potential of short-term warfarin in reducing cardiovascular risks after surgical AVR with bioprosthetic valves. However, the rebound effect observed between short- and long-term warfarin use warrants further investigation, noted the researchers.