High Rate of Undiagnosed Major Risk Factors in Ischemic Stroke

Medscape Medical News
Pauline Anderson

June 30, 2022

Almost two thirds of patients with acute ischemic stroke have at least one undiagnosed major risk factor, new research shows.

The most common of these are dyslipidemia (TL: unhealthy levels of fats in the blood), hypertension, and atrial fibrillation (AF). In addition, many of the study participants were women and were relatively younger.

These results highlight the need for greater clinician awareness about how this patient population may have unrecognised stroke risk factors, says study investigator André Rêgo, MD, Stroke Centre, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland, told Medscape Medical News.

He used the example of a younger female patient who lives a sedentary lifestyle, eats an unbalanced diet, takes oral contraceptives, and smokes. “If you add one or two more risk factors, like an undiagnosed dyslipidemia or mild hypertension, that can be a dangerous cocktail,” he said.

The findings were presented at the Congress of the European Academy of Neurology (EAN) 2022.

Need for Greater Focus on Prevention

Research shows about 90% of strokes are caused by modifiable risk factors, including hypertension, dyslipidemia, diabetes, AF, structural cardiac disease, high body mass index, smoking, psychosocial issues, physical inactivity, and unhealthy diet.

Some of these risk factors, such as overweight or obesity, are obvious; others, like hypertension and dyslipidemia, are frequently silent.

The analysis included 4354 patients from a database of patients admitted to a single centre within 24 hours of a stroke between 2003 to 2018.

About 25.8% were unaware of having major risk factors, and 74.2% had diagnosed risk factors. Participants’ mean age was 59.02 years in the unaware group and 73.8 years in the aware group.

When comparing risk factors between the two study groups, investigators focused on hypertension, dyslipidemia, AF, and silent/new coronary heart disease combined with an ejection fraction of less than 35%.

Of the 25.8% of patients with acute ischemic stroke who were unaware that they had stroke risk factors, 67.7% had at least one major risk factor.

In patients with previously undiagnosed risk factors, 61.4% had newly detected dyslipidemia, hypertension (23.7%), AF (10.2%), diabetes (5.2%), ejection fraction of less than 35% (2.0%), and coronary disease (1.0%).

“These results were kind of surprising because in Switzerland, the healthcare system is really good and people are highly educated,” said Rêgo.

The unaware group had a higher percentage of smokers as well as more non-White and younger patients. These patients were also less likely to have taken aspirin at stroke onset and more likely to be overweight. Women who were unaware of their stroke risk factors were more likely to be taking contraceptives. There was also a higher frequency of patent foramen ovale–related strokes in the unaware group.

Rêgo believes a combination of elements probably contributes to the underdiagnosis of stroke risk factors, including poor healthcare access and individuals perceiving themselves to be healthy if they’re young and not overweight.

Analysis of long-term functional outcomes showed no differences between groups in modified Rankin scale scores after adjusting for age, sex, peripheral artery disease, chronic kidney disease, depression, psychosis, and cancer.

“This probably means that irrespective of etiology, we are treating stroke patients quite well,” said Rêgo.

The results may not be generalizable to other countries, he said, noting that Switzerland is “highly developed” with an educated, relatively healthy population. “If we did this study in another context, we probably would see even more undiagnosed risk factors.”

Improving the detection of undiagnosed risk factors would require a shift in focus, said Rêgo. “We still have a healthcare system excessively directed toward acute disease and less to chronic diseases and preventive medicine.”

Room for Improvement

Commenting for Medscape Medical News, Nicola Rifino, MD, Cerebrovascular Department, University of Milano-Bicocca, Milan Italy, who chaired the session featuring the research, said that the study “sends a clear message” that much more can be done to prevent cerebrovascular ischemic events.

That more than two thirds of patients have undiagnosed vascular risk factors “is certainly surprising,” but this finding could serve as “an incentive for clinicians to do more in prevention,” he said.

He noted that many risk factors are treatable, both pharmacologically and with changes in lifestyle. “Identifying and treating these risk factors early can likely prevent many of the ischemic strokes that occur on a daily basis.”

Dr Rêgo reports no relevant conflicts of interest.

Congress of the European Academy of Neurology (EAN) 2022. Abstract # A-22- 04456. Presented June 26, 2022.