Natural history of silent lacunar infarction: 10-year follow-up of a community-based prospective study of 0.5 million Chinese adults

Zilong Hao,Yiping Chen,Neil Wright,Haiqiang Qin,Iain Turnbull,Yu Guo,Christiana Kartsonaki,Sam Sansome,Peipei Peipei,Canqing Yu,Qijun Gu,Jianming Hu,Jun Lv,Liming Li,Ming Liu,Yongjun Wang,Robert Clarke,Zhengming Chen

doi:10.1016/j.lanwpc.2021.100309

Abstract

BackgroundWidespread use of brain imaging in China has resulted in an increased prevalence of silent lacunar infarct (LACI) in addition to symptomatic LACI, but their clinical relevance is not fully understood. MethodsWe compared the 5-year risks of recurrent stroke and all-cause mortality for silent LACI vs symptomatic LACI in a prospective study of 489,597 Chinese adults with no history of stroke or ischemic heart disease at baseline. Data on recurrent stroke and all-cause mortality were obtained by linkage with local stroke and mortality registries and health insurance records for all hospital admissions. FindingsAmong 12,150 cases with an adjudicated diagnosis of first-ever LACI, 4,134 (34%) had silent LACI and 8,016 (66%) had symptomatic LACI. All cases had brain imaging, but only 33% of silent LACI and 40% of symptomatic LACI cases had brain magnetic resonance imaging (MRI). The standardized event rates for silent LACI were 2-fold greater in urban than rural areas, but the ratios of silent LACI vs symptomatic LACI were similar in all areas. Cases with silent LACI vs symptomatic LACI had comparable 5-year risks of recurrent stroke (38% vs 43%) and all-cause mortality (11% vs 14%), respectively. For both silent and symptomatic LACI cases, most cases of recurrent stroke had non-LACI (70% vs 72%). While the relative risks of recurrent stroke did not differ by age, sex and area, the absolute risks of all-cause mortality varied by sex, age and area. InterpretationThe prognosis of cases with silent LACI was comparable with symptomatic LACI, and the results highlight the need for further randomized trials assessing the efficacy and safety of established treatments for ischemic stroke in cases with silent LACI. FundingWellcome Trust (212946/Z/18/Z, 202922/Z/16/Z, 104085/Z/14/Z, 088158/Z/09/Z) and National Key Research and Development Program of China (2016YFC0900500, 2016YFC0900501, 2016YFC0900504, 2016YFC1303904) and National Natural Science Foundation of China (91843302); UK Medical Research Council (MC_UU_00017/1,MC_UU_12026/2 MC_U137686851), Cancer Research UK (C16077/A29186; C500/A16896) and British Heart Foundation (CH/1996001/9454). ZH was supported West China Hospital, Sichuan University (ZYGD18009 and 2016YFC1300505) for a visiting scholarship to the University of Oxford, UK, during 2018-19.

Highlights

Silent lacunar infarcts (LACI) are covert cerebral ischemic lesions that are detected on brain imaging examinations of individuals presenting with non-specific or atypical neurological symptoms without the classical features of an acute stroke [1]
Cases with silent LACI had comparable baseline characteristics as those with symptomatic LACI, but were more likely to be female (61% vs 54%), and less likely to have diabetes (10% vs 13%) or hypertension (19% vs 22%) (Table 1)
The absolute rates of silent LACI varied by 10-fold between study areas, the ratios of silent LACI vs symptomatic LACI were similar in each area

Summary

Introduction

Silent lacunar infarcts (LACI) are covert cerebral ischemic lesions that are detected on brain imaging examinations of individuals presenting with non-specific or atypical neurological symptoms without the classical features of an acute stroke [1]. Widespread use of brain imaging in China has resulted in increased detection of silent LACI in hospital settings [10,11], with estimated prevalence rates of 20%. Widespread use of brain imaging in China has resulted in an increased prevalence of silent lacunar infarct (LACI) in addition to symptomatic LACI, but their clinical relevance is not fully understood. Methods: We compared the 5-year risks of recurrent stroke and all-cause mortality for silent LACI vs symptomatic LACI in a prospective study of 489,597 Chinese adults with no history of stroke or ischemic heart disease at baseline. Cases with silent LACI vs symptomatic LACI had comparable 5-year risks of recurrent stroke (38% vs 43%) and all-cause mortality (11% vs 14%), respectively. ZH was supported West China Hospital, Sichuan University (ZYGD18009 and 2016YFC1300505) for a visiting scholarship to the University of Oxford, UK, during 2018-19

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