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.


Prediction of 10-Year Cardiovascular and All-Cause Mortality in Rheumatoid Arthritis Using the Ankle-Brachial Index.

Ramirez3,  Carlos, Escalante2,  Agustin, Sahai3,  Mrisa, Battafarano1,  Daniel F., Pogosian3,  Samvel, Rincon2,  Inmaculada Del

Brooke Army Medical Ctr, San Antonio, TX
UTHSCSA, San Antonio, TX
UTHSCSA

Introduction:

The ankle-brachial index (ABI) is a non-invasive test of lower limb arterial function that can be readily performed at the bedside. It provides information about arterial flow obstruction and also about arterial wall rigidity. The ABI is frequently abnormal in rheumatoid arthritis (RA) patients. However, this is not often recognized, and its clinical significance is underappreciated. We examined the association between the ABI and 10-year cardiovascular (CV) and all-cause mortality in an RA cohort.

Methods:

We studied a cohort of RA patients recruited from private and public rheumatology clinics. We measured the ABI as the systolic pressure of the lower limb arteries divided by that of the brachial arteries. A normal ABI varies from 0.91 to 1.3; while ABI <= 0.9 is considered obstructed, and ABI > 1.3 is incompressible. Vital status of patients was updated annually. All reports of death were confirmed by death certificate. CV deaths were defined by any mention of a CV condition in the death certificate. We plotted Kaplan-Meier survival curves, and used Cox proportional hazards regression to adjust for potential confounders.

Results:

We measured the ABI in 644 RA patients, among whom it was normal in 489 (76%), obstructed in 83 (13%) and incompressible in 72 (11%). Observation time from enrollment until death or last follow-up was 6,498 patient years (a median of 10.4 years per patient). During this time, 160 deaths occurred, for a mortality rate of 2.5 per 100 patient-years (95% CI 2.1, 2.9). Of these deaths, 90 were due to CV causes, for a CV mortality rate of 1.5 per 100 patient-years (1.2, 1.9). CV mortality rates per 100 patient years among patients with a normal ABI was 1.1 (0.8, 1.4); among patients with obstructed ABI mortality was 2.1 (1.3, 3.5), hazard ratio (HR) 2.0 (1.1. 3.6); and in patients with incompressible ABI CV mortality was 5.5 (3.1, 6.7), HR 4.4 (2.7, 7.2). Multivariable adjustment for demographic variables, measures of RA activity and damage and CV risk factors, attenuated the association of mortality with arterial obstruction, but did not efface that with incompressible lower limb arteries. The Figure shows a Kaplan-Meier plot of the all-cause survival function according to ABI.

Conclusion:

Incompressibility of the peripheral arteries in RA patients is associated with increased CV and all-cause mortality. The ABI, a non-invasive test performed at the bedside with readily available equipment, is a potentially useful method to stratify mortality risk in RA.

To cite this abstract, please use the following information:
Ramirez, Carlos, Escalante, Agustin, Sahai, Mrisa, Battafarano, Daniel F., Pogosian, Samvel, Rincon, Inmaculada Del; Prediction of 10-Year Cardiovascular and All-Cause Mortality in Rheumatoid Arthritis Using the Ankle-Brachial Index. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1049
DOI: 10.1002/art.28816

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