Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Risk of Cardiovascular Events in Rheumatoid Arthritis Patients Treated with Subsequent-Line Biologic Disease Modifying Antirheumatic Drugs After Switching From First-Line Anti-Tumor Necrosis Factor Agents.

Johnston1,  Stephen, Turpcu2,  Adam, Shi1,  Nianwen, Moawad2,  Dalia, Alexander3,  Kimberly

Thomson Reuters, Washington, DC
Genentech, South San Francisco, CA
Genentech, Inc., South San Francisco, CA

Background/Purpose:

Rheumatoid arthritis (RA) patients frequently switch drug treatments. Little information exists on the risk of cardiovascular events among patients treated with subsequent-line (SL) biologic disease modifying antirheumatic drugs (BIO) after switch from first-line (FL) anti-tumor necrosis factor agents (aTNF). In addition, information is lacking on the relative risk of CV events in patients treated with SL aTNF agents or SL abatacept vs. SL rituximab.

Objectives:

Compare the risk of cardiovascular events in RA patients treated with various SL BIO.

Methods:

Retrospective analysis of Thomson Reuters MarketScan® Commercial and Medicare databases, a large U.S. administrative claims dataset. RA patients initiating FL anti-TNF therapy from 1/1/2004–3/31/2010 were identified and followed forward in time to capture all SL BIO episodes through 3/31/2010. SL episodes were constructed as time from initiation of a SL BIO until switch to another SL BIO, disenrollment, or 3/31/2010. SL episodes were classified into 1 of 5 SL BIOs: abatacept (ABA); adalimumab (ADA); etanercept (ETN); infliximab (INF); rituximab (RTX). Cardiovascular events, as identified by International Classification of Disease, ninth revision, clinical modification criteria, included the following: acute myocardial infarction, other acute and subacute forms of ischemic heart disease, ventricular arrhythmias, cardiac arrest, and atrial fibrillation/flutter. Multivariable Cox proportional hazards survival models compared the hazard of cardiovascular events across the SL BIOs with RTX as the reference group. The hazard models adjusted for important demographic and clinical confounders identified 12-months prior to initiation of SL BIO.

Results:

A total of 4,332 SL episodes were identified: mean age 55 yrs; 80% female. Total person-years exposure by SL BIO were ABA 942, ADA 1,716, ETN 1,349, INF 777, 452 RTX. Average duration of follow-up was similar between SL BIOs (range: 1.1–1.3 yrs). Cardiovascular events occurred in 146 SL BIO episodes overall. The incidence rates of cardiovascular events per 100 person-years of observation were 2.1 INF, 2.4 RTX, 2.7 ADA, 3.0 ETN, 3.3 ABA. As compared to RTX, the adjusted hazard of cardiovascular events was not significantly higher for INF (HR 1.3 95% CI: 0.6–2.8), ABA (HR 1.6 95% CI: 0.8–3.2), ADA (HR 1.8 95% CI: 0.9–3.5), and ETN (HR 1.8 95% CI: 0.9–3.5).

Conclusion:

The risk of cardiovascular events did not differ significantly between patients treated with SL aTNF agents or SL abatacept compared to patients treated with SL rituximab. As an observational study, results may be impacted by channeling or residual confounding. Findings are also limited by the infrequency of cardiovascular events.

To cite this abstract, please use the following information:
Johnston, Stephen, Turpcu, Adam, Shi, Nianwen, Moawad, Dalia, Alexander, Kimberly; Risk of Cardiovascular Events in Rheumatoid Arthritis Patients Treated with Subsequent-Line Biologic Disease Modifying Antirheumatic Drugs After Switching From First-Line Anti-Tumor Necrosis Factor Agents. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :113
DOI:

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