Are lacunar strokes really different? A systematic review of differences in risk factor profiles between lacunar and nonlacunar infarcts

Abstract

Background and purpose: Differences in risk factors between lacunar and nonlacunar infarcts might support a distinct arterial pathological process underlying lacunar infarction.

Methods: We did a systematic review of studies comparing risk factors in patients with lacunar versus nonlacunar infarction. For each risk factor, we calculated study-specific and pooled relative risks (RRs) for lacunar versus nonlacunar infarction.

Results: A total of 16 of 28 studies included risk factors in their ischemic stroke subtype definitions. Hypertension and diabetes appeared commoner among patients with lacunar versus nonlacunar infarction. However, analyses confined to studies using risk factor-free ischemic subtype definitions found only a marginal excess of hypertension with lacunar versus nonlacunar infarction (RR, 1.11; 95% CI, 1.04 to 1.19) and no difference for diabetes (RR, 0.95; 95% CI, 0.83 to 1.09). Atrial fibrillation and carotid stenosis were associated more with nonlacunar than lacunar infarction but less so when only studies using risk factor-free classifications were considered. Otherwise, there was no evidence of differences in risk factor profiles.

Conclusions: Risk factor-free ischemic stroke subtype classification methods should be used for comparing risk factor profiles between lacunar and nonlacunar subtypes.

Figure 1

RRs (lacunar vs nonlacunar) for hypertension, grouped by ischemic stroke subtype classification method. The RR for each study is shown as a square, with size denoting statistical weight of the study. Horizontal lines represent 95% CIs. Diamonds represent pooled RRs, with 95% CIs represented by the width of the diamonds. N indicates total number of lacunar or non-lacunar patients; n, number of lacunar or non-lacunar patients with hypertension; RR, relative risk; CI, confidence interval. Heterogeneity between four groups: χ²_3df=18.22; P=0.0004.

Figure 2

RRs (lacunar vs nonlacunar) for diabetes, grouped by ischemic stroke subtype classification method. Figure format as in Figure 1. N indicates total number of lacunar or non-lacunar patients; n, number of lacunar or non-lacunar patients with diabetes; RR, relative risk; CI, confidence interval. Heterogeneity between four groups: χ²_3df=18.22; P=0.0004.