Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


A Longitudinal Study of the Prolongation of the Corrected QT Interval in Anti-Ro/SSA Positive Adults with Systemic Lupus Erythematosus.

Bourre-Tessier3,  Josiane, Huynh5,  Thao, Clarke4,  Ann E., Bernatsky1,  Sasha R., Joseph3,  Lawrence, Belisle3,  Patrick, Pineau2,  Christian A.

McGill UHC/RVH, Montreal, QC, Canada
McGill Univ Health Center, Montreal, QC, Canada
McGill University
Montreal General Hospital, Montreal, QC, Canada
Montreal General Hospital

Background:

Electrocardiographic (ECG) abnormalities such as congenital heart block (CHB), bradycardia and prolongation of the corrected QT interval (QTc) are known to occur in newborns who passively acquired anti-Ro/SSA antibodies through maternal transfer. In adults, studies of the association between QTc prolongation and anti-Ro/SSA are conflicting. The goal of our study was to examine whether anti-Ro/SSA antibodies are associated with an increased risk of corrected QT (QTc) prolongation in a large systemic lupus erythematosus (SLE) cohort and to examine the stability of this relationship over a longitudinal follow-up period.

Methods:

Two cross-sectional studies were conducted. Patients fulfilling ACR criteria for SLE were invited to undergo a 12-lead resting ECG between March 2002 and March 2005 in study 1, and between April 2005 and March 2006 in study 2. QTc's greater than or equal to 440msec were considered prolonged. Multivariate logistic regression models were performed to assess the association between anti-Ro/SSA and prolonged QTc. Other potentially associated factors examined included age, sex, disease duration, lupus activity (SLEDAI), damage (SLICC/ACR DI), potassium and magnesium levels and medications with the potential to prolong QTc interval (antimalarials, beta-blockers, antiarrhythmics, antibiotics, tricyclics and tetracyclics, selective serotonin reuptake inhibitors [SSRI], domperidone and human immunodeficiency virus [HIV] protease inhibitors).

Results:

Study 1 included 150 subjects and study 2, 278 subjects. 118 subjects had participated in both studies, with a mean time (SD) of 505 (256) days between the 2 ECGs and of 512 (258) days between anti-Ro/SSA measurements. For these 118 subjects, most (92.4%) were female, the mean age at baseline was 45.4 years (14.2) and the mean lupus duration was 13.0 years (10.8). Mean SLEDAI was 3.3 (3.8) and median SLICC/ACR DI was 1.0 (interquartile range 0, 3). Cross-sectional analysis of prolonged QTc's on the presence of anti-Ro/SSA showed an OR (95%CI) of 12.6 (2.3–70.7) for the study 1, and of 5.1 (1.5–17.4) for the study 2. In the majority of subjects (75.4%), the anti-Ro/SSA and QTc status did not change over the observation interval. For 2 patients (1.7%), both QT and anti-Ro decreased and for one patient (0.9%), both increased. 25 patients (21.2%) changed only one of their status, and only a single participant (0.9%) had anti-Ro/SSa and QTc statuses that changed in an opposite direction (anti-Ro/SSA increased and QTc decreased).

Conclusion:

The presence of anti-Ro/SSA antibodies was associated with QTc prolongation in a large SLE cohort. This cross-sectional relationship was preserved upon longitudinal follow-up. Since prolongation of the QTc is known to increase the risk of ventricular arrhythmias and sudden death, patients with anti-Ro/SSA may be exposed to a prolonged period of increased risk of cardiac events. ECG screening should be considered, so that patients with QTc prolongation could receive appropriate counseling to avoid drugs that may put them at risk for life-threatening arrhythmias.

To cite this abstract, please use the following information:
Bourre-Tessier, Josiane, Huynh, Thao, Clarke, Ann E., Bernatsky, Sasha R., Joseph, Lawrence, Belisle, Patrick, et al; A Longitudinal Study of the Prolongation of the Corrected QT Interval in Anti-Ro/SSA Positive Adults with Systemic Lupus Erythematosus. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1142
DOI: 10.1002/art.28908

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