Abstract 292: Long-Term Warfarin Therapy is Associated with Tissue Calcification: Influence of Treatment Duration, Age, and Gender
Background: Recent studies have suggested that warfarin therapy may be linked to cardiac valve calcification. We aimed to establish whether calcification (C) of valves or other tissue occurs with warfarin and to examine if such C was influenced by treatment duration, age, or gender.
Methods: We performed a retrospective chart review of 100 patients; 50 long-term warfarin recipients and 50 untreated controls, matched for age, gender, and comorbidities. For inclusion, patients required a recent echocardiogram (within 18 months) and at least one CT-scan and X-ray. We determined a calcification score (CS) for each patient; 1 point per site was given for C reported in the aortic, mitral, or tricuspid valve, aorta, coronary and carotid arteries, peripheral vessels, kidney, lung, or other locations. We recorded the patients’ age, incidence of comorbidities, and primary indication for warfarin use.
Results: The groups were matched for the incidence of hypertension, diabetes, and coronary artery disease (P=NS); however, males were younger (64±3 vs 73±2 years; P=0.03). Most patients received warfarin for either valve replacement (42%) or atrial fibrillation (36%), with a mean treatment duration of 99±3 months. Our analysis revealed 5 primary results
Warfarin-associated CS was increased in cardiac valves (P=0.01 vs control) and at each assessed site except the coronary arteries.
Total CS was higher with warfarin (2.7±0.3) than controls (1.8±0.2; P=0.02).
CS correlated with warfarin treatment duration (P=0.03).
When all patients were assessed, CS correlated with age for both groups, but was always higher with warfarin (P<0.02 vs control; ANCOVA).
However, this effect was exclusively due to warfarin-induced C in males. Total CS was higher for warfarin-treated males (2.4±0.4) versus controls (1.2±0.2; P±0.01), irrespective of age (P<0.01; ANCOVA). In contrast, we found no group differences between warfarin-treated and control females.
Conclusion: Long-term warfarin therapy was associated with significant increases in tissue calcification not only in valves, but also at other sites. For our entire warfarin-treated group, calcification correlated with treatment duration and age; however, the most pronounced increases occurred in males.