The baseline characteristics of patients in the AMIS trial are summarized in Table 1. Most study participants were Caucasian (92%) and male (~89%) with a mean age of 55 years, body-mass index of 26, and a prevalence of diabetes of 2.6%. The mean APRI values at baseline were 0.34±0.46 in the placebo and 0.33±0.22 in the aspirin groups. Only 2.5% of individuals (n=113) had baseline APRI higher than 0.7.
Characteristic Placebo (n=2 257) Aspirin (n=2 267) Age (years) 54.9±7.9 54.8±8.1 Male 89.4% 88.4% Ethnicity White 91.5% 91.7% Black 5.9% 6.3% Hispanics 2.6% 2.0% BMI 26.0±3.5 25.9±3.5 Diabetes 2.8% 2.5% Smoking Never 27.2% 27.5% Former 5.4% 5.3% Current 19.2% 19.7% Alcohol consumption Daily drink (>1.5 ounces) 15.4% 15.9% Laboratory results Platelet count (×109 /L) 253±70 257±70 AST (IU/L) 32±34 31±15 ALP (IU/L) 62±22 64±23 Bilirubin (mg/dL) 0.7±0.3 0.7±0.3 APRI 0.34±0.46 0.33±0.22
Table 1. Baseline characteristics of study participants
Over three years, mean APRI increased in both aspirin and placebo groups compared to baseline. Assignment to aspirin tended to be associated with a greater increase in the rate of change in APRI over time than placebo (difference in the rate of change 0.007 per year; 95% CI 0.002–0.015, P=0.12) (Fig. 1A). There was no significant difference in the rate of changes in platelet counts between the aspirin and placebo groups over time (P=0.4), but a trend toward 0.52 IU/L higher AST annually in the aspirin group compared to the placebo group (95% CI 0.05–1.09, P=0.07) was noted. Among individuals with elevated APRI at baseline (mean APRI of 1.1±0.5 for the aspirin and 1.0±0.4 for the placebo group), APRI values tended to decrease more consistently over time among subjects who received aspirin than among those who received placebo (Fig. 1B), but the differences in changes of APRI over time were not significant between the two groups (P=0.7).
Daily high-dose aspirin does not lower APRI in the Aspirin-Myocardial Infarction Study
- Received Date: 2019-03-18
- Accepted Date: 2019-08-20
- Rev Recd Date: 2019-06-30
- Available Online: 2019-10-24
- Publish Date: 2020-03-01
Abstract: Antiplatelet agents reduce liver fibrosis by inhibiting platelet activation and platelet-derived growth factor production. Previous cross-sectional epidemiological studies suggest that the use of aspirin is related to reduced liver fibrosis. The Aspirin-Myocardial Infarction Study (AMIS) aims to examine this relationship in a multicenter, randomized, double-blind and placebo-controlled trial. The existing clinical trial of aspirin was conducted to study the benefit of one gram aspirin daily among 4 524 individuals who had experienced at least one documented myocardial infarction. The aspartate aminotransferase (AST)-to-Platelet Ratio Index (APRI) was calculated at baseline and annually from the platelet count and AST levels. Participants in the AMIS trial had a mean baseline APRI of 0.34±0.36, and only 1% individuals had APRI scores higher than 1.0, a common cutoff for cirrhosis. The daily use of aspirin was associated with an increase, rather than a reduction of APRI, by 0.007 per year (95% CI 0.002−0.015, P=0.12). The use of aspirin did not significantly affect platelet counts. In a sensitivity analysis of individuals with probable significant fibrosis at baseline (APRI≥0.7), the aspirin group had a sustained reduction in APRI over time, although this change was not significant compared to that in the placebo group. In the AMIS trial, the daily use of high-dose aspirin did not significantly affect APRI, a surrogate index of liver fibrosis. This study highlights the need for de novo clinical trials to investigate the potential benefit of antiplatelet agents on liver fibrosis.
|Citation:||Shilpa Tiwari-Heckler, Z. Gordon Jiang, Yury Popov, Kenneth J. Mukamal. Daily high-dose aspirin does not lower APRI in the Aspirin-Myocardial Infarction Study[J]. The Journal of Biomedical Research, 2020, 34(2): 139-142. doi: 10.7555/JBR.33.20190041|