CHICAGO – Patients with systemic lupus erythematosus (SLE) have an incidence of treatment-resistant hypertension (TRH) twice the rate of matched controls, and all-cause mortality in affected SLE patients is sharply higher than in individuals whose SLE is not complicated by comorbid TRH, Annette Oeser reported at the annual meeting of the American College of Rheumatology.
TRH is thus an important yet underappreciated comorbidity for clinicians to recognize in patients with SLE, added Ms. Oeser of Vanderbilt University, Nashville, Tenn.
She presented a single-center, retrospective study of 1,044 SLE patients and 5,241 controls matched by age, race, and sex. During an average of 6 and maximum of 17 years of follow-up, 10% of SLE patients and 5% of controls developed TRH. The incidence was 14.7 cases per 1,000 person-years in the SLE population and 7.4 per 1,000 in controls. Of note, the incidence curves began to diverge within the first months following diagnosis of the autoimmune disease.
TRH was defined in the conventional way as an inability to achieve a blood pressure of 140/90 mm Hg or less while on three antihypertensive drugs having different mechanisms or as the simultaneous use of four or more antihypertensive agents, noted Ms. Oeser, the study coordinator, who presented the findings on behalf of senior investigator Cecilia P. Chung, MD, a rheumatologist at Vanderbilt.
The SLE patients with TRH were older than those without TRH by a margin of 47 versus 41 years of age. A total of 45% of SLE patients with TRH were black, compared with 21% of those without TRH. The group with SLE and TRH also had a higher C-reactive protein (10.2 versus 3.3 mg/L), a higher erythrocyte sedimentation rate (40 versus 24 mm/hr), a lower estimated glomerular filtration rate (65.0 versus 88.2 mL/min per 1.73 m2), and a higher creatinine (1.1 versus 0.8 mg/day).
Overall, 25% of SLE patients with TRH died during follow-up, as did 10% of those without resistant hypertension, for an unadjusted 289% increased risk of all-cause mortality. Upon adjustment for age, sex, calendar year, end-stage renal disease, and creatinine, the SLE patients with TRH still remained at a 78% increased risk of mortality.
Ms. Oeser and Dr. Chung reported having no financial conflicts regarding the study, which was supported by Vanderbilt University, the Rheumatology Research Foundation, the National Institutes of Health, and the Lupus Research Alliance.
SOURCE: Chung CP et al. Arthritis Rheumatol. 2018;70(Suppl 10): Abstract 706.