Introduction: Small perivascular spaces (SPVS) are gaining momentum as imaging biomarkers of cerebrovascular health.
Hypothesis: SPVS confer vascular risks and the coexistence of SPVS with lacunar infarcts (LI) heightens these risks.
Methods: Stroke-free participants in the population-based Northern Manhattan Study were followed for incident stroke (ischemic and hemorrhagic), MI, all death, vascular death, and any vascular event. Lesions with diameter of 3 mm or less and absence of FLAIR rim were classified as SPVS on a semi-quantitative scale (range 0 to 28). We defined “high SPVS burden” as the upper quintile and compared the rate of vascular events in this group to individuals in the lower 4 quintiles combined. LI were defined as lesions greater than 3 mm with associated FLAIR rim, round shape, and typical location. Cox models were used to calculate risks of outcomes after adjusting for confounders.
Results: This analysis includes 1208 NOMAS participants (40% male, 65% Hispanic; mean age 71 ± 9 years at time of MRI) followed a mean of 6 ± 2 years. SPVS were present in 91% of the sample (median SPVS scale score 5). Compared to participants with a lesser burden of SPVS, participants with a high SPVS burden had a higher incidence rate per 1000 person-years of death (48 vs 34), vascular death (20 vs 11), ischemic stroke (12 vs 7) and any vascular event (37 vs 24). After adjusting for demographics and vascular risk factors, participants with a high burden of SPVS had a higher risk of death (HR 1.35, 1.00-1.78), vascular death (HR 1.55, 0.96-2.51), any stroke (HR 1.53, 0.91-2.57), MI (HR 1.29, 0.69-2.41), and any vascular event (HR 1.50, 1.07-2.11). The presence of lacunar infarcts was an effect modifier such that those with LI and a high SPVS burden had a greater risk of vascular death (B=0.63, P=0.03), any stroke (B=0.72, P=0.03) and any vascular event (B=0.54, P=0.02) compared to those without LI.
Conclusions: In this multi-ethnic, population-based study, participants with a high burden of SPVS had increased incidence rates of vascular events. Furthermore, the joint presence of SPVS and LI heighten the risk of vascular death, any stroke and any vascular event. The presence of SPVS may help select subjects for randomized trials to assess intervention strategies.