Background:The vulnerability of cardiovascular disease (CVD) patients' health abilities, combined with the severity of the disease and the overlapping risk factors, can cause such people to bear the economic burden of the disease due to the use of medical services.We estimated the economic burden of patients with CVD and identified the weak link in the design of the medical insurance. Methods:Data from 5,610 middle-aged and elderly with CVD were drawn from the 2015 wave of China Health and Retirement Longitudinal Study (CHARLS). The recommended method of the World Health Organization (WHO) was adopted to calculate catastrophic health expenditure (CHE), impoverishment by medical expenses (IME), and applied the treatment-effect model to analyze the determinants of CHE. Results:The incidence of CHE was 19.9% of the CVD, compared to 7.6% of the sample households trapped in IME. The incidence of CHE in CVD participating in medical insurance was 2.6% higher than for uninsured families (16.3%).Family size, health satisfaction,combine with other chronic diseases, having hospitalization and disabled members, and participating in insurance were found to be significantly associated with the likelihood of CHE. Conclusions:Elderly with physical vulnerabilities were more prone to CHE. The medical insurance only reduced barriers to accessing health resources for elderly with CVD, but lacked policy inclination for high-utilization populations,and had poorly accurate identification of vulnerable characteristics of CVD,which in turn affects the economic protection ability of the medical insurance. The dispersion between the multiple medical security systems leads to the existence of blind spots in the economic risk protection of individuals and families. Keywords:cardiovascular disease, catastrophic health expenditure, impoverishment by medical expense, medical insurance, elderly households Background Aging, rapid urbanization, and shifting disease patterns are causing cardiovascular disease (CVD) to become established as one of the primary diseases in the world. 1.2 Worldwide, roughly 17.9 million people die of CVD each year, and the absolute number of deaths from chronic CVD worldwide increased by 42. 4% between 1990-2015 ( 2017). 3,4 The incidence and mortality of CVD are also serious in China. As of 2015, there were 290 million people suffering from CVD in China, including Out-of-pocket health expenditure :OOP Household consumption expenditure:EXP Instrumental Variable :IV Declarations Ethics approval and consent to participateNot applicable Consent for publicationNot applicable Availability of data and materialsDataset available from the CHARLS repository,