Risk Factors Are Frequently Inadequately Treated in Patients With Stroke or TIA

In patients with ischemic stroke and transient ischemic attack (TIA) there is a significant gap between evidence-based cerebrovascular risk factors control and real-world stroke prevention, according to study results published in Neurology.

While previous studies have found poor lifestyle and modifiable risk factors are common in patients with ischemic stroke, limited data are available on risk factor control in patients with stroke/TIA.  The goal of the study was to assess the prevalence of inadequately treated risk factors in a large cohort of patients with stroke/TIA.

The observational cohort study included patients from the Poststroke Disease Management STROKE-CARD trial (ClinicalTrials.gov Identifier: NCT02156778). Of 2625 adult patients with acute ischemic stroke or TIA admitted to the University Hospital Innsbruck, Austria, between January 2014 and December 2017, the study population comprised 1730 patients (median age 72 years, 59.6% men), including 1424 stroke patients and 306 patients with TIA.  Of these, 1382 were first-ever strokes/TIAs.

Overall, 79.5% of subjects had at least one inadequately treated stroke risk condition before the index event. Hypercholesterolemia (53.4% of the study population) and hypertension (45.7%) were the most common risk factors, followed by atrial fibrillation (12.5%), previous atherosclerosis cardiovascular disease (12.4%), diabetes mellitus (9.9%), unrecognized TIA (2.7%), carotid stenosis (2.1%), and mechanical heart valves (0.5%). 

When modifiable lifestyle risk behaviors were included as inadequately-treated risk factors, the percentage of subjects with at least 1 inadequately treated stroke risk condition before the index event was 95.1%. Many subjects had more than 1 uncontrolled risk factor (eg, 72.3% had at least 2 inadequately treated risk factors).

The number of inadequately treated risk factors was higher in patients with recurrent stroke/TIA, compared with patients with first-ever events (P <.001), in younger patients (≤75 years) compared with patients >75 years of age (P <.001), and in male patients (P =.003).

Assessment of stroke preventability with adequate risk factors control revealed that blood pressure control could have prevented 237 events (13.7%), while rigorous lipid profile control could have prevented 182 events (10.5%) and proper anticoagulation in patients with pre-diagnosed atrial fibrillation could have prevented 145 events (8.4%).  On the other hand, the estimated degree of stroke preventability with adequate anticoagulation in patients with mechanical heart valves was low (0.4%).

For the 5 most relevant risk factors combined (hypertension, hypercholesterolemia, atrial fibrillation, smoking, and overweight), the estimated degree of stroke preventability was 1 in 2, assuming an additive effect, and 1 in 4 with a highly conservative computation approach.

The study had several limitations, according to the researchers, including lack of consensus on the definition of adequate control of risk factors, missing information on pre-stroke blood pressure profiles, lack of valid way to assess the quality of diet and physical activity.

“Population-wide campaigns, individualized prevention and poststroke disease management programs, and an increased awareness among physicians about the concept of stroke preventability are required to reduce the global burden of stroke,” conclude the researchers.

Reference

Boehme C, Toell T, Mayer L, et al. The dimension of preventable stroke in a large representative patient cohort. [published online Oct 31, 2019]. Neurology. doi:10.1212/WNL.0000000000008573