Colchicine Use Among Patients with Gout Significantly Reduces Incidence of MI
SAN DIEGO, CA—Patients with gout who actively took colchicine had a significantly reduced incidence of myocardial infarction (MI) vs. never users, results of an interim analysis presented at the 2013 ACR/ARHP Annual Meeting has found.
Also reduced were person-year incidence rates compared with patients who had a colchicine lapse (defined as any period of non-use ≥2 weeks after medication cessation to account for elimination time) and with a pooled group of patients not on colchicine, noted D. Barry Crittenden, MD, Instructor of Medicine in the Division of Rheumatology at NYU Langone Medical Center, New York, NY, and colleagues.
The group's preliminary data suggested colchicine may reduce MI among patients with gout. To assess the possible effect of colchicine on risk of MI further, they initiated a retrospective cohort study in all active NY Harbor Veterans Affairs patients with an ICD-9 code for gout or hyperuricemia from 2000—2009.
“Charts were manually screened to confirm gout diagnosis (ACR criteria) and pharmacy records were used to identify subjects on daily colchicine for ≥30 days (colchicine group),” they stated. The control group comprised subjects who did not receive colchicine. They excluded those who did not meet gout criteria or who had received PRN colchicine only. Primary outcome was MI during the study period.
Of the 7819 patients identified with requisite ICD-9 codes, 4486 charts have been reviewed to date; 844 met ACR gout criteria and 644 were enrolled, Dr. Crittenden noted. Of these, 410 (64%) used colchicine (1184 person-years of active use and 682 person-years of lapse) and 234 (36%) did not use colchicine (1041 person-years of follow-up).
Baseline characteristics did not differ significantly between the colchicine and control groups; 99.3% vs. 97.4% were male, respectively; age was 66 vs. 67 years; BMI 30.5 vs. 30.2 kg/m2; mean serum urate 8.4 vs. 8.0 mg/dL; hypertension 80.2% vs. 80.8%; diabetes 29.5% vs. 29.5%; hyperlipidemia 50.7% vs. 43.2%; coronary artery disease 24.1% vs. 26.1%; chronic kidney disease 20.7% vs. 24.8%; active tobacco use 21.2% vs. 17.1%; and medication use, which included allopurinol 22.0% vs. 20.1%, aspirin 30.5% vs. 32.1%, and NSAIDs 37.8% vs. 34.2%.
Patients who used colchicine experienced 11 MIs, 8 of which occurred during lapse time (2%) and 3 during active use (0.7%). Control patients had 7 MIs (3%; active colchicine vs. control, P=0.04).
“The shortest time from last colchicine use to MI was 2 months (mean 4 months),” they noted. “We also compared rates of MI per person-year exposure to colchicine, control, lapse, and pooled control and lapse periods, and observed significant differences between colchicine active use vs. lapse (P=0.02), and vs. lapse and control (P=0.04).”Incidence of MI per person-year of exposure has not reached statistical significance for the active colchicine group; however, it may do so if current rates persist through the remaining data collection. “Evaluation of the remaining 3333 patients is ongoing,” they concluded.