, results of a retrospective, single-center investigation suggest.
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Risk of atherosclerotic vascular events was increased by 73% for patients with systemic lupus erythematosus (SLE) who sustained a mean blood pressure of 130/80 to 139/89 mm Hg over 2 years in the study, which included 1,532 patients treated at a clinic in Toronto.
Management of hypertension in SLE patients should start early, and should aim to achieve levels below 130/80 mm Hg, according to the investigators, led by Konstantinos Tselios, MD, PhD, of the Centre for Prognosis Studies in the Rheumatic Diseases at the University of Toronto.
“The findings of the present study support that the target BP should be less than 130/80 mm Hg in all patients with lupus in order to minimize their cardiovascular risk,” Dr. Tselios and coauthors said in their study, which appears in Annals of the Rheumatic Diseases.
Despite the limitations inherent in a retrospective, observational study, this work by Dr. Tselios and colleagues may help inform the care of patients with SLE, according to C. Michael Stein, MBChB, professor of medicine at Vanderbilt University in Nashville, Tenn.
“It’s really interesting data that’s important and helps us think in terms of figuring out what may be reasonable to do for a particular patient,” Dr. Stein said in an interview.
Starting antihypertensive management early and aiming at levels below 130/80 mm Hg is a strategy that should be “reasonable” for most patients with SLE, said Dr. Stein, adding that the approach specified in the 2017 American College of Cardiology/American Heart Association (ACC/AHA) hypertension guidelines are appropriate to follow. In those guidelines, the threshold for diagnosis of hypertension was lowered to 130/80 mm Hg.
“You can start with risk factor modification, in terms of losing weight, exercising, stopping alcohol, and decreasing salt in the diet to see if you can get the blood pressure down, though it may come down to drug therapy for many patients, I believe,” Dr. Stein said.
Authors of those 2017 ACC/AHA guidelines made no recommendations for patients with SLE or other connective tissue diseases, despite including a section devoted to specific patient subgroups and comorbidities of interest, Dr. Tselios and coauthors noted in their report.
Management of hypertension in patients with lupus may be “delayed” in patients with blood pressures reaching the current hypertension threshold, according to Dr. Tselios and colleagues, due in part to difficulties in cardiovascular risk calculation in SLE patients, as well as current risk considerations outlined in the guidelines.
“On the basis of the recent guidelines, the patient with typical lupus (young female with no traditional atherosclerotic risk factors) would be considered as a low-risk individual and not offered treatment for a BP of 130-139/80-89 mm Hg,” they said in their report.
Accordingly, Dr. Tselios and colleagues sought to determine whether the new hypertension definition predicted atherosclerotic vascular events, including new-onset angina, acute myocardial infarction, cerebrovascular events, revascularization procedures, heart failure, or peripheral vascular disease requiring angioplasty, in patients with SLE treated at a Canadian clinic.
Their analysis comprised 1,532 patients with SLE who had at least 2 years of follow-up and had no prior atherosclerotic events on record. Over a mean follow-up of nearly 11 years, there were 124 such events documented in those patients.
With a mean follow-up of nearly 11 years, the incidence of atherosclerotic events was 18.9 per 1,000 patient-years for patients with blood pressure ≥ 140/90 mm Hg, 11.5 per 1,000 patient-years for the 130-139/80-89 mm Hg group, and 4.5 per 1,000 patient-years for those with blood pressures of 130/80 mm Hg or lower, with differences that were statistically significant between groups, according to the report.
An adjusted blood pressure of 130-139/80-89 mm Hg over the first 2 years since enrollment in the clinic was independently associated with the occurrence of an atherosclerotic event, with a hazard ratio of 1.73 (95% confidence interval, 1.13-2.69, P = 0.011), according to results of a multivariable analysis.
Those findings support targeting a blood pressure below 130/80 mm Hg in all patients with lupus, according to Dr. Tselios and coauthors.
“It seems reasonable that clinicians should not rely on CV risk calculators in SLE and commence treatment as soon as possible in cases of sustained BP elevation above the threshold of 130/80 mm Hg,” they wrote in their report.
How low to go remains unclear, however, as targeting lower levels of blood pressure might be unsafe in certain groups, such as those SLE patients with prior heart disease or heart failure; nevertheless, recent observational data from non-SLE populations suggest that effective treatment to levels lower than 130/80 mm Hg would “further reduce the incidence of atherosclerotic events in SLE,” the authors said in a discussion of their results.
Dr. Tselios and coauthors said they had no competing interests relative to the study. They reported funding for the University of Toronto Lupus Clinic from the University Health Network, Lou & Marissa Rocca, Mark & Diana Bozzo, and the Lupus Foundation of Ontario.
SOURCE: Tselios K et al. Ann Rheum Dis. 2020 Mar 10. doi: 10.1136/annrheumdis-2019-216764