Migraine Elevates the Risk of Perioperative Stroke

The investigators adjusted for confounders, including sex, age, BMI, emergent versus nonemergent surgery, prescriptions of antiplatelet drugs or beta blockers within four weeks before surgery, minutes of intraoperative hypotension, diabetes, hypertension, atrial fibrillation, Charleston Comorbidity Index, and work relative value units (ie, a surrogate for surgical complexity).

The cohort included 10,179 individuals with migraine (8.2%). Of the patients with migraine, 12.6% had migraine with aura.

Patients with migraine generally were younger, had higher BMI, and were more likely to be women. They were less likely to have diabetes or hypertension and to be taking antiplatelet drugs or beta blockers. Patients with migraine “were a little healthier” than the patients without migraine, Dr. Houle said.

In all, 771 patients had perioperative stroke, of whom 89 (11.5%) had migraine. About 0.6% of patients without migraine had perioperative stroke versus 0.9% of patients with migraine. The unadjusted odds ratio for stroke among migraineurs was 1.47, and the adjusted odds ratio was 1.75. “Individuals in this sample who had any migraine were at greater risk for stroke during the period after surgery, just like in the regular population,” said Dr. Houle. Although migraine without aura was not a statistically significant risk factor for stroke in the general population, it was after surgery.

Prediction Models

In one sensitivity analysis, the researchers determined each patient’s stroke risk based on known risk factors excluding migraine, such as age and cardiovascular disorders, and grouped patients by low, intermediate, and high levels of risk. Among patients in the low-risk group, the relative risk of stroke for patients with migraine versus patients without migraine was 3.5-fold higher. “These are people you would not have identified as having risk,” said Dr. Houle.

Future studies should try to identify the mechanisms involved in this relationship and assess interventions to mitigate the risk of stroke in patients with migraine who undergo surgery, Dr. Houle said.

Dr. Houle and colleagues have created a stroke prediction model that includes migraine and will “give surgeons a risk model to predict the risk of stroke for their patients,” he said. The model will “realize the risks that we uncovered in this study.”

—Jake Remaly

Suggested Reading

Schürks M, Rist PM, Bigal ME, et al. Migraine and cardiovascular disease: systematic review and meta-analysis. BMJ. 2009;339:b3914.

Spector JT, Kahn SR, Jones MR, et al. Migraine headache and ischemic stroke risk: an updated meta-analysis. Am J Med. 2010;123(7):612-624.

Timm FP, Houle TT, Grabitz SD, et al. Migraine and risk of perioperative ischemic stroke and hospital readmission: hospital based registry study. BMJ. 2017;356:i6635.