Statin Use Postradiation Tied to Significant Stroke Reduction

Stephanie Edwards

July 01, 2019

Patients with known coronary artery disease (CAD) who took statins after radiation therapy (RT) for cancer of the thorax, head, or neck showed a significant reduction in stroke and a trend toward a reduction in cardiovascular and cerebrovascular events, a new study suggests.

In a retrospective cohort study of 5718 cardiac patients who underwent radiation between 2000 and 2011 for thorax or head or neck cancer, researchers assessed the impact of statin use on vascular outcomes. Of these, 4166 were statin users and 1552 were not on statins.

"We demonstrated that statin use was associated with a significant 32% reduction in stroke and with a strong trend toward reducing the composite outcome of cardiovascular and cerebrovascular events," said corresponding author Negareh Mousavi, MD, MHSc, Department of Medicine, McGill University Health Centre, Montreal.

He added that the study "raises the need for prospective randomized controlled trials to definitively establish the benefit of statins in this at-risk population and define guidelines on the management of radiation-induced vascular disease."

The article was published online in the Journal of the American Heart Association.

Vincent Bufalino, MD, Advocate Heart Institute, Naperville, Illinois, who was not involved in the research, said this study shows a "fascinating conclusion."

Bufalino told theheart.org | Medscape Cardiology that "for those of us who live in this world every day, we know that statins work. They work in addition to heart disease, they work in patients with cerebral disease and, in this case, they worked in patients who had cancer and also had vascular disease."

He agreed that more trials and scientific research need to be done to understand the relation between radiated arteries and statins.

Promising Results

RT is an effective treatment for many types of cancer; however, exposure to this therapy puts patients at a greater risk for cardiovascular and cerebrovascular disease and is the leading cause of morbidity and mortality in cancer survivors, the authors say.

"There are no studies exploring whether statins reduce vascular complications in cancer patients post thorax, head, and neck radiotherapy," Mousavi said in an interview. Accordingly, this observational study, the largest of its kind to date, aimed to explore whether statins reduce radiation-induced cardiovascular and cerebrovascular complications in cancer patients after radiotherapy to the thorax, head, and neck, he said.

Patients were taken from a total dataset of 380,000 people older than 45 years in the Quebec population who had coronary angiography, acute coronary symptoms, or who underwent a coronary revascularization procedure between August 2000 and March 2011. Only patients older than 65 years were included because they are the only subset with universal drug coverage.

The primary outcome of interest was the occurrence of any cerebrovascular event (transient ischemic attack, stroke, carotid revascularization, or stroke death) or cardiovascular event (myocardial infarction [MI] or fatal MI). A secondary outcome was the occurrence of stroke alone, the authors write.

Adjustments were made for age, sex, atrial fibrillation, coronary artery disease, previous MI, chronic kidney disease, cerebrovascular disease, diabetes mellitus, dyslipidemia, heart failure, and hypertension.

Statin use after radiotherapy was associated with a nonsignificant 15% reduction in the primary outcome, but a significant 32%reduction in stroke alone.

Outcomes With and Without Postradiotherapy Statin Treatment
Outcome Statin Users, n = 4166
n (%)
Non-Statin Users, n = 1552
n (%)
Hazard Ratio (95% Confidence Interval) P Value
Stroke/MI/Death 376 (9.0) 160 (10.3) 0.85 (0.69–1.04) .0811
Stroke 110 (2.6) 56 (3.7) 0.68 (0.48–0.98) .0368

The authors note limitations with the database, such as smoking status and statin dosing, as well as the inability to consider all confounding variables. Despite these limitations, this study offers "a promising insight into the potential benefits of lipid-lowering therapies post RT," they conclude.

The authors disclose that the views expressed are those of the author and do not reflect official policy of Fort Belvoir Community Hospital, the Defense Health Agency, the Department of Defense, or the US Government.

J Am Heart Assoc. Published online June 19, 2019. Full text

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