Migraine History Impacts Ischemic Stroke Risk

History of migraine increased the risk for perioperative ischemic stroke within 30 days of surgery, according to the results of a study published recently in BMJ.

“The observed association remained consistent after adjustment for a large number of disease and surgery related risk factors for ischemic stroke,” wrote Fanny P. Timm, a medical student with Massachusetts General Hospital and Harvard Medical School, and colleagues. “The migraine associated risk of perioperative ischemic stroke was highest in patients with migraine with aura, ambulatory patients, and patients with migraine with an otherwise low a priori estimated risk of ischemic stroke based on preoperative and intraoperative predictors of perioperative ischemic stroke.”

According to the study, perioperative stroke is associated with a significantly increased risk for mortality and long-term morbidities. Prior observational and experimental studies had linked a history of migraine with an increased risk for ischemic stroke.

In this analysis, Timm and colleagues collected data from 124,558 surgical patients who underwent procedures at Massachusetts General Hospital or two satellite campuses from January 2007 to August 2014. The primary outcome was perioperative ischemic stroke within 30 days of surgery.

Of the patient population, 8.2% of patients had any migraine diagnosis, as defined by ICD-9 codes. Of these patients, 12.6% had migraine with aura. During the study period, 771 (0.6%) perioperative strokes occurred. Of the patients with stroke, 11.5% had a diagnostic code for migraine, and 2.3% had a code for migraine with aura.

Results showed that patients with a history of migraine were at a 75% increased risk for perioperative ischemic stroke (adjusted odds ratio=1.75; 95% CI, 1.39-2.21) compared with patients without migraine. The risk for ischemic stroke was almost threefold higher among patients with migraine with aura (adjusted OR=2.61; 95% CI, 1.59-4.29), and also increased among patients with migraine without aura (adjusted OR=1.62; 95% CI, 1.26-2.09) compared with surgical patients without migraine.

“The results of our study add to the emerging evidence that migraine, particularly migraine with aura, should be considered a marker for increased risk of ischemic stroke, and our data extend this association to the perioperative setting,” the researchers wrote. “We contend that this association has clinical relevance in a growing list of risk factors that should be considered to promote disability-free survival.”

The predicted absolute risk was 2.4 perioperative ischemic strokes for every 1,000 surgical patients. This risk increased to 4.3 per 1,000 patients with any migraine diagnosis: 3.9 for migraine without aura and to 6.3 for migraine with aura.

Finally, the researchers found that patients with migraine also had a higher rate of hospital readmissions within 30 days of discharge (adjusted OR=1.31; 95% CI, 1.22-1.41).

“Migraine is known to be associated with a variety of comorbidities, which are mainly cardiovascular, cerebrovascular, and neurologic,” the researchers wrote. “In our study, patients with migraine were more likely to be readmitted not only owing to perioperative stroke, neurologic symptoms, or other diseases of the circulatory system, but also for ‘signs, symptoms, and ill-defined conditions,’ such as pain, syncope/collapse, or nausea/vomiting and diseases of the digestive system’.”

“General practitioners must be aware of increased risks of postoperative readmission to hospital in patients with migraine, not only because of known associations such as vascular comorbidities but also due to gastrointestinal disease and circulatory problems,” they wrote.

Timm FP, et al. Migraine and risk of perioperative ischemic stroke and hospital readmission: hospital based registry study. BMJ. Epub 2017 Jan 10.