Assessing the Effect of ACC/AHA Hypertension Definition on Atherosclerotic Vascular Events in SLE

Even slightly elevated blood pressure (130-139/80-89 mm Hg) can lead to a 2.5-fold increase in the risk for atherosclerotic cardiovascular events (AVEs) in patients with systemic lupus erythematosus (SLE), according to study results published in Annals of Rheumatic Diseases.¹

The study focused on the revised 2017 definition of hypertension established by the American College of Cardiology/American Heart Association (ACA/AHA) guidelines. The revised guidelines notably omitted any consideration of patients with autoimmune disorders, including SLE, who face increased risk for AVEs. The study assessed the impact of the revised definitions of hypertension on the risk for AVEs in hypertensive and normotensive patients with SLE.

Researchers enrolled 1532 patients from the Toronto Lupus Clinic who had ≥2 years of follow-up and no prior AVE. The study divided patients into 3 groups according to their mean blood pressure (BP) over the last 2 years: ≥140/90 mm Hg, 130-139/80-89 mm Hg, and <130/80 mm Hg. Of these patients, 155 (10.1%) had a BP ≥140/90 mm Hg, 316 (20.6%) had a BP of 130-139/80-89 mm Hg, and 1061 (69.3%) were normotensives (<130/80 mm Hg). Patients were followed up until the first occurrence of an AVE (fatal or nonfatal coronary artery disease, cerebrovascular event or peripheral vascular disease) or their last visit over a mean follow-up of 10.8 years. Researchers compared each group with baseline atherosclerotic risk factors. A multivariable, time-dependent analysis adjusted for the presence of other risk factors. Kaplan-Meier analysis measured cumulative risk for first AVE over time in all groups of patients.

Study results revealed a 73% increased risk for AVEs in patients in the mildly hypertensive group (130-139/80-89 mm Hg), independent of all traditional and SLE-related risk factors for AVEs. Incidence rates for AVEs were 18.9 in the highly hypertensive group (≥140/90 mm Hg), 11.5 in the mildly hypertensive group, and 4.5 in the normotensives per 1000 patient-years (P =.0007 between the mildly hypertensive group and normotensives). Moreover, in the mildly hypertensive group, a mean BP of 130-139/80-89 mm Hg over the  first 2 years was independently associated with the occurrence of AVEs (hazard ratio, 1.73; 95% CI, 1.13-2.65; P =.011).

Investigators deliberately deviated from the ACC/AHA definition of BP based on ≥2 readings on 2 separate occasions.² In patients with SLE, BP fluctuates considerably, driven not only by SLE flares but also by the increased use of glucocorticosteroids and/or nonsteroidal anti-inflammatory drugs, as well as by renal involvement.³ In patients with SLE, time-adjusted BP reflects cumulative exposure to hypertension over time, presenting a more reliable measure of blood pressure than single BP readings, and a more accurate prediction of AVEs in patients with lupus.⁴

“In all [prior] studies, the threshold for the definition of hypertension was ≥140/90 mm Hg,” the investigators concluded. “[T]he application of a lower threshold, such as the 130-139/80-89 mm Hg, may further increase the [effect] of hypertension on the [cardiovascular] risk of patients [with SLE].”

References

1. Tselios K, Gladman DD, Su J, Urowitz M. Impact of the new American College of Cardiology/American Heart Association definition of hypertension on atherosclerotic vascular events in systemic lupus erythematosus [published online March 10, 2020]. Ann Rheum. doi:10.1136/annrheumdis-2019-216764

2. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American heart association task force on clinical practice guidelines. Circulation. 2018;138(17):e484-e594.

3. Tselios K, Koumaras C, Urowitz MB, Gladman DD. Do current arterial hypertension treatment guidelines apply to systemic lupus erythematosus patients? A critical appraisal. Semin Arthritis Rheum. 2014;43(4):521-525.

4. Nikpour M, Urowitz MB, Ibanez D, Harvey PJ, Gladman DD. Importance of cumulative exposure to elevated cholesterol and blood pressure in development of atherosclerotic coronary artery disease in systemic lupus erythematosus: a prospective proof-of-concept cohort study. Arthritis Res Ther. 2011;13(5):R156.

This article originally appeared on Rheumatology Advisor