There was an increase in the prevalence of adult Brazil residents classified as being at high risk for a coronary events (HRC) between 2013 and 2019, and the prevalence of at least one of the conditions that characterize a significant atherosclerotic disease or its equivalent was greater than 10%, highlighting diabetes mellitus, chronic renal failure, and history of stroke in two periods analyzed. These findings show that more than 10% of Brazilian adults have at least 20% of risk for an acute coronary event in the next ten years if there are no more effective measures with a longitudinal and integral approach to prevent and care for individuals with CNCD (14, 15). Also considering that in this study it was only possible to carry out the first phase of risk stratification, it is believed that the prevalence of HRC in the Brazilian population may be higher than that observed in the present study as evidenced by studies carried out with the 2013 HNS subsample, which found a prevalence of 38.1% of HRC in the adult population between the ages of 45 and 64 years according to the I Brazilian Guidelines on Cardiovascular Prevention (16), and 19.4% according to the Framingham score, being 8.7% in women and 21.6% in men (17). It is noteworthy that studies, the stratification of cardiovascular risk was performed with a subsample of the National Health Survey (2013), in which laboratory tests and measurement of blood pressure were measured.
These results are related to the accelerated population ageing that occurred in Brazil in the last five decades which is associated with urbanization, industrialization, and westernization of habits and lifestyles (1, 7, 27–28), which has contributed to the increase in the incidence, prevalence, and mortality of non-communicable diseases. They can also be evaluated as a positive indicator of access to health services necessary for the diagnosis of a disease (DM, angina, chronic renal failure, and acute myocardial infarction) and/or for performing surgical procedures for performing a bypass graft and/or placement of stents (8, 29).
It is believed that the greater access of Brazilians to clinical and laboratory diagnostic tests due to the implementation of the universal and free SUS, contributed to the increase in the longevity of individuals affected by CNCD (9). Confirmation of this hypothesis can be seen by comparing three Brazilian population surveys carried out between 2008 and 2019, which show an increase in the proportion of medical appointments in the last year and an increase in the coverage of the family health strategy, characterizing increased access to services among individuals with some CNCD (30).
Despite the advances observed after the implementation of the SUS, there are still weaknesses in reducing exposure to risk factors, creating environments that make them accessible and encourage healthy choices, in addition to weaknesses in the provision of a line of care with the ability to detect early conditions of intermediate health care for a coronary events, promote timely treatment and reduce sequelae and deaths, especially in geographic regions of greater socioeconomic vulnerability (11, 31).
In the present study, the highest prevalence of high risk for coronary events was observed in residents of the Center-South region of Brazil and this finding may be related to the fact that this region has an older population and is in a more advanced stage of the demographic transition, where there are higher rates of incidence, prevalence and mortality from CNCDs (7, 10, 27, 30, 32). In addition, these locations have the most organized Health System and greater access to health services at all levels of care complexity, reducing the lethality of CNCDs and increasing the prevalent cases of these morbidities (9, 30–31). Thus, these findings may be related to the survival bias present in cross-sectional studies.
In addition to the geographic region of residence, other socioeconomic and demographic variables that remained related to high risk for a coronary event swere the male gender, age, and being in a labour activity at the time of the interview.
The higher prevalence of HRC in men can be associated greater exposure to factors risk for chronic non-communicable diseases, especially with regard to smoking, alcohol abuse and non-adherence to the treatment of CNCDs that predispose them to get sick and die from these diseases (10, 16, 33–34).
The association between high risk for a coronary events and advancing age was an expected result since aging generates greater stiffening of the arteries and peripheral vascular resistance, a physiological situation that, associated with prolonged exposure to risk factors for CNCD, increases the incidence and prevalence of cardiovascular diseases (1–2, 4, 6–7, 17, 28), as well as related disabilities to these diseases. Therefore, the higher prevalence of HRA observed among individuals who self-rated their health as regular, bad or very bad, was not surprising and was similar to that verified by a study that estimated cardiovascular risk in the Brazilian population in ten years, according to the Framingham score (17). The incapacities generated by complications of CNCDs and by changes related to advancing age may also explain the fact that there is a higher prevalence of HRC among those who reported limited activity due to the presence of arterial hypertension (1–4, 6–7, 17, 28).
In addition, the lower prevalence of HRC in individuals who reported work activities at the time of the surveys can be explained by the fact that the comorbidities used in the first stage of risk stratification of the I Brazilian Guidelines for Cardiovascular Prevention are more prevalent in the elderly and are related to disabilities that make it impossible to work (3), and thus, possibly, many of the individuals at high risk for a coronary event would already be retired due to age or disability, or on sick leave for health treatment in the context of the surveys.It is noteworthy that the incapacity to work related to CNCDs and their sequelae cause a great financial impact on the Health System, social security, income and quality of life of individuals and their families (1–2, 5–6). Studies have shown that the reduction in income associated with the presence of CNCDs increases the exposure of these families to risk factors for these morbidities at the same time reducing access to health services and adoption of preventive measures, contributing to the vicious cycle of poverty-related to CNCDs (1–2, 5–6).
In the present study among the risk factors for CNCDs, we highlight the history of smoking in the past, the score of consumption of ultra-processed foods (sweets, soft drinks and sweets) and the abusive consumption of alcohol, which remained associated with high risk for a coronary event after adjusting the multiple model.
It is believed that the association between past smoking history and HRC e and the non-association with current smoking, may be related to the survival bias present in prevalence studies. Thus, individuals with comorbidities used in risk stratification, who maintain the habit of smoking, are more likely of complications and death in relation to individuals who no longer smoke.
Regarding the food consumption, results from the bivariate analysis differed from other studies (4, 10, 33, 35), as there was a lower prevalence of high risk for a coronary event (HRC) in Brazilians with medium and high consumption of ultra-processed foods. This result does not mean that ultra-processed foods are important determinants of high risk for a coronary event. In contrast, a higher prevalence was observed in individuals with medium and high consumption of fruits, vegetables and fish. A profile similar to that observed in relation to high salt consumption and alcohol abuse.
These results may be related to survival bias, as individuals at high risk for a coronary event who maintained poor eating habits and alcohol abuse are at higher risk of complications and death (4, 10, 35). Furthermore, these findings may be associated with reverse causality that may appear in cross-sectional studies, as it is not possible to determine the temporality between the dependent variable and the independent variables. It is important to highlight that after multiple analyses and investigation of possible interactions between the variables, the contradictory results were not maintained. There was a significant interaction term between alcohol abuse and the diagnosis of hypertension, increasing the prevalence of high risk for a coronary events as well as between BMI and high cholesterol, and between the score of consumption of ultra-processed foods and high cholesterol.
The relationship between alcohol consumption and cardiovascular risk is still controversial. There are studies that prove the benefits of moderate consumption, but heavy consumption has been associated with increased cardiovascular risk, increased blood pressure, increased risk of diabetes mellitus and stroke (36–38).
The excess of weight, represented by overweight and obesity, is also considered one of the main risk factors for diseases of the circulatory system and predisposes individuals to other risk factors such as physical inactivity, hypertension, diabetes mellitus and dyslipidemia. Therefore, it is expected that the interaction between dyslipidemia and overweight would increase the probability of a coronary events (4, 10, 14, 35, 39).
The interaction between the consumption of ultra-processed foods and high cholesterol reflects the nutritional transition, driven by the process of urbanization and westernization of habits and lifestyle, which has intensely changed food consumption in various locations, due to greater access to ultra-processed foods, in addition to the high cost of fresh foods such as fruits and vegetables. This context has increased the risk of circulatory system diseases, especially in low-income and vulnerable populations (7, 40–41). This fact may also be related to the increased prevalence of high risk for a coronary events when there was an interaction between the consumption of ultra-processed foods and high cholesterol since the cardiovascular risk associated with the medium and high consumption of ultra-processed foods is related to a high intake of cholesterol, lipids and saturated fatty acids, which associated with low fibre consumption, participate in the aetiology of dyslipidemia, obesity, diabetes and arterial hypertension (40–41).
The results of the present study should be carefully evaluated, as its data sources are cross-sectional surveys in which information on health history can be associated with differentiated access to health services, in addition to survival bias and reverse causality. In addition, this is a study of initial screening of high risk for a coronary events, in which only the first step of stratification of the Global Risk Score (GRS) was performed. However, it makes a great contribution to the monitoring of Non-Communicable Diseases, as it is a study whose surveys are nationally representative, with internal validity of the information (13, 42), signalling for the increase in the prevalence of high risk for a coronary event among population surveys, with more than 12% of the adult Brazilian population in 2019.
It is believed that this prevalence may increase in the coming years, due to the effect of the fiscal adjustment period implemented in 2016 through Constitutional Amendment 95 associated with the economic and health crisis promoted by the COVID-19 pandemic (43–45). Studies have shown an increase in exposure to unhealthy eating, sedentary lifestyle, alcohol abuse, and smoking in Brazilians during the pandemic, with a higher prevalence of exposure among Brazilians living with CNCD (45). And if collective health actions are not implemented to ensure access to protective factors and health services, especially for low-income Brazilians, Brazil may not achieve the goals established in the "Strategic Action Plan for Confronting CNCDs in Brazil, 2011–2022" and in the Sustainable Millennium Development Goals. As an increase in the prevalence and mortality due to CNCDs is expected due to the increase in risk factors, reduction in the search for preventive exams, the difficulty of SUS in meeting demand related to the pandemic together with the care of users with CNCDs (43–46).