Targeted treatments for atherosclerosis may reduce the risk for stroke subtypes, including lacunar and large artery stroke, according to research published in JAMA Network Open.
Researchers examined the relationship among carotid atherosclerosis, major cardiovascular risk factors, and ischemic stroke subtypes. Using data from the China Kadoorie Biobank study, study investigators randomly chose 23,973 participants (61.9% women) to further assess. Participants had no history of cardiovascular disease at enrollment and had available carotid artery ultrasonographic measurements.
At baseline, 3.1% of participants used anti-hypertensive medications, and at resurvey, that number increased to 8%. Similarly, the use of lipid-lowering medications also increased, from 0.1% at baseline to 0.7% at resurvey. Among patients without stroke, 28.5% presented with carotid artery plaque >1.5 mm vs 60.6% of patients with stroke. Mean carotid intima-media thickness (cIMT) was 0.69 ± 0.16 mm and 0.8 ± 0.19 mm in patients with and without stroke, respectively. In addition, 54.8% of ischemic stroke cases were adjudicated as either lacunar (27.6%) or nonlacunar (27.2%) whereas 45.2% remained unconfirmed.
After adjustment for age, sex, and geographic area, plaque burden and cIMT values illustrated log-linear positive associations with risk for ischemic stroke (adjusted odds ratio [OR] 1.34; 95% CI, 1.26-1.44; P <.001).
Researchers conducted additional adjustments for blood pressure (OR 1.26; 95% CI, 1.17-1.35), smoking status (OR 1.24; 95% CI 1.16-1.33), and diabetes (OR 1.24; 95% CI, 1.15-1.33). Further adjustment for cIMT reduced the OR further (OR 1.22; 95% CI, 1.13-1.31; P <.001), but the association remained statistically significant.
According to the results, baseline systolic blood pressure was found to have a “substantially stronger” association with ischemic stroke compared with plaque burden (OR per standard deviation [SD] 1.51; 95% CI, 1.42-1.61 and OR per SD 1.34; 95% CI, 1.26-1.44; P <.001 for both). Smoking score and diabetes were more weakly associated (OR per SD 1.11; 95% CI, 1.04-1.2 and OR per SD 1.08; 95% CI, 1.03-1.14; P =.002 for both).
After adjustment for blood pressure, plaque was persistently associated with large artery (OR per SD 1.43; 95% CI, 1.24-1.63) and lacunar stroke (OR per SD 1.25; 95% CI, 1.1-1.43) but not probable cardioembolic stroke (OR per SD 1.06; 95% CI, 0.83-1.36).
Several study limitations were noted. Although brain imaging data were available, the adjudication process did not distinguish between large artery and cardioembolic nonlacunar strokes. Cardioembolic stroke is not common in China, resulting in less intensively managed cardiovascular risk factors, and, finally, data may have been subject to causality bias in carotid artery measurements.
“Carotid artery imaging in large-scale studies is feasible and informative for distinguishing the underlying pathophysiologic characteristics of ischemic stroke subtypes,” the researchers of the study concluded, “and data from such imaging may lead to a better understanding of the potential benefits of different drug treatments for the prevention of different subtypes of ischemic stroke.”
Parish, Arnold, and Collins reported the receipt of both grants and personal fees from a variety of sources, including the British Heart Foundation and Merck & Co., Inc. For a full list of disclosures, please see the full text of the study online.
Parish S, Arnold M, Clarke R, et al. Assessment of the role of carotid atherosclerosis in the association between major cardiovascular risk factors and ischemic stroke subtypes. JAMA Netw Open. 2019;2(5):e194873.