Hypoalbuminemia is associated with reduced response to aspirin in patients with stable coronary artery disease

Background: Serum albumin (SA) is a powerful cardiovascular prognostic marker, suggested to be involved in regulation of platelet function. High on-aspirin platelet reactivity (HAPR) is associated with increased risk for deleterious cardiovascular events. The current study aimed to evaluate the association between HAPR and albumin levels in patients with coronary artery disease (CAD).

Methods: Patients with known stable CAD, who were taking aspirin (75-100 mg qd) for at least a month were screened. Exclusion criteria: cancer, sepsis, active inflammatory/rheumatic disease, recent major surgery, chronic liver failure, other anti-platelet drugs and thrombocytopenia. Blood was drawn from the participants and sent for SA level and platelet function test (VerifyNow). HAPR was defined as aspirin reaction units (ARU) >550.

Results: Overall 116 patients were analyzed; age 69 ±10, 28% women. Twenty (17%) were hypoalbuminemic (≤3.5 g/dL). Hypoalbuminemic group was similar to the normal albumin group except mildly creatinine in the former. Mean ARU was significantly higher in the hypoalbuminemic vs. the normal albumin group (548±45 vs. 444±66 ARU, respectively, p<0.001). A significant inverse association was observed between SA and ARU with (figure 1). Multivariate analysis adjusted for potential confounders found that albumin ≤3.5 is a strong predictor of HAPR (HR=4.9, 95%CI=2.2-32, p=0.002).

Conclusions: Hypoalbuminemia is strongly associated with HAPR among patients with stable CAD.

Figure 1: Aspirin reactivity levels (ARU) by serum Albumin levels