Aspirin Exposure Fails to Reduce Cardiovascular Event Risk

Heidi Splete

April 18, 2022

The addition of aspirin to standard guideline management for blood pressure did not reduce the risk of cardiovascular events among adults with hypertension and controlled systolic blood pressure in a study.

The benefits of aspirin use for the primary prevention of atherosclerotic cardiovascular disease (ASCVD) have been questioned in light of data showing neutral outcomes in low-risk patients and concerns about increased bleeding risk and mortality in healthy older adults, wrote Rita Del Pinto, MD, of University of L'Aquila (Italy) and colleagues in JAMA Network Open.

In the study, Del Pinto and colleagues conducted a post hoc analysis of data from more than 2,500 participants in SPRINT (Systolic Blood Pressure Intervention Trial), a multicenter, randomized trial conducted from 2010 to 2013.

The goal of SPRINT was to compare intensive and standard blood pressure–lowering strategies for hypertension patients. The primary outcome of the current study was risk of a first cardiovascular event, which included adjudicated myocardial infarction, non–myocardial infarction acute coronary syndrome, stroke, acute heart failure, and CVD death."There has been considerable improvement in the management of cardiovascular risk factors since the first reports on aspirin use for cardiovascular prevention," Del Pinto said in an interview.

"As for hypertension, not only have more effective antihypertensive medications become available, but also evidence has recently emerged in support of a downwards redefinition of blood pressure targets during treatment," she said. "In this context, in an era when great attention is paid to the personalization of treatment, no specific studies had addressed the association of aspirin use as a primary prevention strategy in a cohort of relatively old, high-risk individuals with treated systolic blood pressure steadily below the recommended target," she added.

The researchers assessed whether aspirin use in addition to standard blood pressure management (a target of less than 140 mm Hg) decreased risk and improved survival.

The study population included 2,664 adult patients; 29.3% were women, and 24.5% were aged 75 years and older. Half of the patients (1,332) received aspirin and 1,332 did not.

In a multivariate analysis, 42 cardiovascular events occurred in the aspirin group, compared with 20 events in those not exposed to aspirin (hazard ratio, 2.30). The findings were consistent in subgroup analyses of younger individuals, current and former smokers, and patients on statins.

An additional subgroup analysis of individuals randomized to standard care or intensive care in the SPRINT study showed no significant difference in primary outcome rates between individuals who received aspirin and those who did not. The rates for aspirin use vs. non–aspirin use were 5.85% vs. 3.60% in the standard treatment group and 4.66% vs. 2.56% in the intensive treatment group.

The study findings were limited by several factors, including the post hoc design, short follow-up period, and lack of data on the initiation of aspirin and bleeding events, the researchers wrote. However, the results suggest that modern management of hypertension may have redefined the potential benefits of aspirin in patients with hypertension, they concluded.

Findings Confirm Value of Preventive Care

"The study was conducted as a post-hoc analysis on an experimental cohort, which must be considered when interpreting the results," Del Pinto said.

Despite the limitations, the study findings affirm that effective treatment of major cardiovascular risk factors, such as hypertension, with proven drugs is "a mainstay of the primary prevention of ASCVD," she emphasized.

As for additional research, "Testing our findings in a dedicated setting with sufficiently long follow-up, where aspirin dose and indication, as well as any possible bleeding event, are reported could expand the clinical meaning of our observations," said Del Pinto. "Also, the clinical impact of aspirin, even in combination with novel cardiovascular drugs such as direct oral anticoagulants, in populations exposed to combinations of risk factors, deserves further investigation."

Data Support Shared Decision-Making

"While recent evidence has not shown a benefit of aspirin in the primary prevention of ASCVD in several populations, the subpopulation of patients with hypertension as an ASCVD risk factor is also of interest to the clinician," Suman Pal, MD, of the University of New Mexico, Albuquerque, said in an interview. "The lack of benefit of aspirin in this study, despite its limitations, was surprising, and I would be eager to see how the role of aspirin in ASCVD prevention would continue to evolve in conjunction with improvement in other therapies for modification of risk factors."

"The decision to continue aspirin in this subgroup of patients should warrant a discussion with patients and a reexamination of risks and benefits until further data are available," Pal emphasized.

Larger studies with long-term follow-ups would be required to further clarify the role of aspirin in primary prevention of ASCVD in patients with hypertension without diabetes or chronic kidney disease, he added.

Data were supplied courtesy of BioLINCC. The study received no outside funding. The researchers and Pal had no financial conflicts to disclose.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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