Causes of ischemic stroke in young adults versus non-young adults: A multicenter hospital-based observational study

Abstract

Background: Very few comparative studies have focused on the differences in the causes of ischemic stroke between young adults and non-young adults. This study was performed to determine what causes of ischemic stroke are more important in young adults than in non-young adults using a large-scale multicenter hospital-based stroke registry in Fukuoka, Japan.

Methods and results: We investigated data on 15,860 consecutive patients aged ≥18 years with acute ischemic stroke (mean age: 73.5 ± 12.4 years, 58.2% men) who were hospitalized between 2007 and 2019. In total, 779 patients were categorized as young adults (≤50 years of age). Although vascular risk factors, including hypertension, diabetes mellitus, and dyslipidemia, were less frequent in young adults than in non-young adults, the prevalence of diabetes mellitus and dyslipidemia in young adults aged >40 years were comparable to those of non-young adults. Lifestyle-related risk factors such as smoking, drinking, and obesity were more frequent in young adults than in non-young adults. As young adults became older, the proportions of cardioembolism and stroke of other determined etiologies decreased, but those of large-artery atherosclerosis and small-vessel occlusion increased. Some embolic sources (high-risk sources: arterial myxoma, dilated cardiomyopathy, and intracardiac thrombus; medium-risk sources: atrial septal defect, nonbacterial thrombotic endocarditis, patent foramen ovale, and left ventricular hypokinesis) and uncommon causes (vascular diseases: reversible cerebral vasoconstriction syndrome, moyamoya disease, other vascular causes, arterial dissection, and cerebral venous thrombosis; hematologic diseases: antiphospholipid syndrome and protein S deficiency) were more prevalent in young adults than in non-young adults, and these trends decreased with age.

Conclusions: Certain embolic sources and uncommon causes may be etiologically important causes of ischemic stroke in young adults. However, the contribution of conventional vascular risk factors and lifestyle-related risk factors is not negligible with advancing age, even in young adults.

Fig 1. Prevalence of vascular risk factors according to age among young adults versus non-young adults.

Prevalence of hypertension, diabetes mellitus, dyslipidemia, and smoking is shown in patients of each age category (18–30 years, 31–35 years, 36–40 years, 41–45 years, 46–50 years, and non-young adults [>50 years]). *P < 0.05 vs. non-young adults by multiple comparison.

Fig 2. Prevalence of lifestyle-related risk factors according to age among young adults versus non-young adults.

Prevalence of smoking, drinking, and obesity is shown in patients of each age category (18–30 years, 31–35 years, 36–40 years, 41–45 years, 46–50 years, and non-young adults [>50 years]). *P < 0.05 vs. non-young adults by multiple comparison.

Fig 3. Proportion of stroke subtypes according to age among young adults versus non-young adults.

Proportions of cardioembolism (high-risk sources and medium-risk sources), large-artery atherosclerosis, small-vessel occlusion, other determined cause (arterial dissection and others), and undetermined cause are shown in patients of each age category (18–30 years, 31–35 years, 36–40 years, 41–45 years, 46–50 years, and non-young adults [>50 years]).

Fig 4. Frequency of embolic sources in young adults and non-young adults.

Frequency of embolic sources in young adults (closed columns) and non-young adults (open columns) is shown according to risk stratification (high- and medium-risk embolic sources) among patients with ischemic stroke due to cardioembolism. When patients had multiple embolic sources, all potential sources were listed. *P < 0.05, higher in young adults than in non-young adults. †P < 0.05, lower in young adults than in non-young adults.

Fig 5. Frequency of uncommon causes in young adults and non-young adults.

Frequency of uncommon causes in young adults (closed columns) and non-young adults (open columns) is shown according to origin (vascular disease, hematologic disease, and other disease) among patients with ischemic stroke due to other determined etiologies. When patients had multiple uncommon causes, all potential causes were listed. *P < 0.05, higher in young adults than in non-young adults. †P < 0.05, lower in young adults than in non-young adults.