WEST PALM BEACH, FLA. – The incidence rate of many cardiovascular events is more than doubled in patients with multiple sclerosis (MS), compared with matched controls without MS, according to a study presented at ACTRIMS Forum 2020. The risk of a major adverse cardiac event (MACE) – that is, a first myocardial infarction, stroke, or cardiac arrest – is approximately twofold higher. Venous thromboembolism and peripheral vascular disease also occur at notably increased rates, reported Rebecca Persson, MPH, and colleagues at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. Ms. Persson is an epidemiologist at the Boston Collaborative Drug Surveillance Program in Lexington, Mass.
Vascular comorbidities are more prevalent in patients with MS than in the general population, but few studies have reported on the incidence of cardiovascular disease after MS diagnosis. To describe rates of incident cardiovascular disease after MS diagnosis and compare them with rates in a matched population without MS, the researchers analyzed data from a U.S. Department of Defense database.
The study included a cohort of 6,406 patients with MS diagnosed and treated during Jan. 2004–Aug. 2017 who had at least one prescription for an MS disease-modifying treatment.
A cohort of 66,281 patients without MS were matched to the patients with MS 10:1 based on age, sex, geographic region, and cohort entry date. The researchers excluded patients with a history of cardiovascular disease or select comorbidities such as dyslipidemia, atrial fibrillation, or a disorder related to peripheral vascular disease. They also excluded patients with a history of treated hypertension or treated type 2 diabetes, defined as diagnosis and treatment within 90 days of each other.
Researchers considered a patient to have a cardiovascular disease outcome – including MI, stroke, cardiac arrest, heart failure, angina or unspecified ischemic heart disease, transient ischemic attack or unspecified cerebrovascular disease, venous thromboembolism, peripheral vascular disease, pericardial disease, bradycardia or heart block, or arrhythmia other than atrial fibrillation or atrial flutter – if the disease was recorded five or more times.
The researchers followed patients from cohort entry until study outcome (separate for each outcome), loss of eligibility, death, or end of data collection. Ms. Persson and colleagues calculated incidence rates (IRs) using the Byar method and incidence rate ratios (IRRs) using Poisson regression for each outcome.
The median age at MS diagnosis or at the matched date was 38 years, and 71% were female. The median duration of record after patients entered the cohort was 7.2 years for patients with MS and 5.3 years for patients without MS.
The IRs of all cardiovascular disease types, with the exception of bradycardia or heart block, were higher for patients with MS, compared with non-MS patients, the researchers reported. Many cardiovascular disease outcomes had IRRs greater than 2. “The incidence of MI was higher among MS patients than among non-MS patients,” the researchers said (IR, 12.4 vs. 5.9 per 10,000 person-years; IRR, 2.11).
“Risk of MACE and risk of stroke were higher among MS patients than among non-MS patients,” the researchers said. Relative risks also were higher among women than among men (2.47 vs. 1.55 for MACE, and 2.19 vs. 1.71 for stroke). When the investigators performed a sensitivity analysis to address the possibility that physicians might misdiagnosis MS symptoms as stroke, the rate of stroke was attenuated among patients with MS, but remained elevated relative to the rate among patients without MS (IRR, 1.63).
The IR of venous thromboembolism was more than 2 times higher among patients with MS than among non-MS patients (38.4 vs. 15.1 per 10,000 person-years; IRR, 2.54), as was the risk of peripheral vascular disease (14.9 vs. 6.0 per 10,000 person-years; IRR, 2.49). The relative risk of peripheral vascular disease was higher in women than men, and the risk in patients with MS increased after age 40 years.
The study was funded by a grant from Celgene, a subsidiary of Bristol-Myers Squibb. Four of Ms. Persson’s coauthors are employees of BMS, and one works for a company that has a business relationship with Celgene.
SOURCE: Persson R et al. ACTRIMS Forum 2020. Abstract P082.