Trends in Mortality Rate from Cardiovascular Disease in Brazil, 1980-2012

Background Studies have questioned the downward trend in mortality from cardiovascular diseases (CVD) in Brazil in recent years. Objective to analyze recent trends in mortality from ischemic heart disease (IHD) and stroke in the Brazilian population. Methods Mortality and population data were obtained from the Brazilian Institute of Geography and Statistics and the Ministry of Health. Risk of death was adjusted by the direct method, using as reference the world population of 2000. We analyzed trends in mortality from CVD, IHD and stroke in women and men in the periods of 1980-2006 and 2007-2012. Results there was a decrease in CVD mortality and stroke in women and men for both periods (p < 0.001). Annual mortality variations for periods 1980-2006 and 2007-2012 were, respectively: CVD (total): -1.5% and -0.8%; CVD men: -1.4% and -0.6%; CVD women: -1.7% and -1.0%; DIC (men): -1.1% and 0.1%; stroke (men): -1.7% and -1.4%; DIC (women): -1.5% and 0.4%; stroke (women): -2.0% and -1.9%. From 1980 to 2006, there was a decrease in IHD mortality in men and women (p < 0.001), but from 2007 to 2012, changes in IHD mortality were not significant in men [y = 151 + 0.04 (R2 = 0.02; p = 0.779)] and women [y = 88-0.54 (R2 = 0.24; p = 0.320). Conclusion Trend in mortality from IHD stopped falling in Brazil from 2007 to 2012.


Introduction
Cardiovascular diseases (CVD) are the main cause of death in the Brazilian population. 1,2 CVDs are responsible for at least 20% of deaths in our population over 30 years old. In the South and Southeast regions of the country, the rate of mortality from CVD was even greater than in other regions. 3 Previous studies have shown consistent data about the downward trend in the mortality rate from CVD in Brazil. 4,5 Deaths by cerebrovascular diseases (CBVD) had greater reduction in mortality rate when compared to ischemic heart disease (IHD). 4 A recent update in CVD mortality data in Brazil and in the metropolitan region of São Paulo showed a downward trend in the rate of mortality from IHD and CBVD between 1990 and 2009. 2 In Brazil, starting in 1987, deaths from IHD were, in men, higher than deaths from CBVD. In women, however, this difference was only noticed as of 1999. Both causes of death showed a downward trend in the period of 1980 -2009, but this trend was more evident in deaths from CBVD. However, in men, from 2007 to 2009, the mortality rate adjusted by age from IHD remained unaltered. Nevertheless, due to the period of only three years, it was not possible to establish a real trend in mortality. This study updated the rate of mortality from cardiovascular diseases in Brazil until 2012. Trends in rate of mortality from CVD, IHD and CBVD in the period of 2007-2012 were also analysed and compared to previous years.

Methods
Rates of mortality from CVD, IHD and CBVD, in Brazil, from 1980 to 2012 and in the periods of 1980-2006 and 2007-2012 were analysed. The data about mortality were obtained on the Ministry of Health of Brazil's website www.datasus.gov.br. Population data, from the Brazilian institute of Geography and Statistics (IBGE), were obtained on the same website. Deaths from 1990 to 1995 were classified according to ICD-9, 9th Review Conference of the International Classification of Diseases (ICD) of 1975, adopted by the 20th World Health Assembly. Starting in 1996, the mortality data were obtained in the 10 th review of the International Classification of Diseases. Diseases of the circulatory system (CDs) were grouped in codes 390 to 459, IHDs in codes 410 to 414, and CBVDs in codes 430 to 438, in the 9 th review of the ICD. Mortality data, starting in 1996, was classified by the 10 th review of the ICD. CDs are grouped in codes 100-199, IHDs in codes 120 to 125, and CBVDs in codes 160 to 169. Mortality after 30 years of age, according to gender, per 100,000 inhabitants, was analysed in the following age groups: 30-39 years of age; 40-49 years of age; 50-59 years of age; 60-69 years of age; 70-79 years of age and ≥ 80 years of age. For comparison, mortality was adjusted by direct method for the age according to standard world population of the year 2000. 6 Simple linear regression was used to analyse the temporal evolution of mortality rate associated to CVD, IHD, and CBVD, followed by the comparison of slopes of regression lines. The level of significance was p < 0.05. The statistical software used was Primer of Biostatistics, version 4.02.9. 7

Discussion
This study showed a trend in the reduction of mortality from cardiovascular diseases from 1980 to 2012, but in the analysis of the period of 2007-2012 no reduction in mortality from IHD was observed in men or women.
Studies showed a trend in the reduction of mortality from cardiovascular diseases in several countries, especially in the more developed countries of Western Europe, USA, and Canada. 8-10 A recent update showed significant reduction in mortality from CVDs in all states of the USA. 10 However, only a small reduction in mortality from IHD was observed in young adults, especially women. 11 Despite the significant discrepancies between death rates from CVD in Europe, many European countries also had an increase or small reduction in mortality from CVD. 12 Control of the risk factor, and improvements in clinical and interventional treatments are the main justifications for the reduction in mortality in more developed countries. 13,14 Just as in our study, a reduction of mortality from such diseases was also observed in developing countries. 15 Even with population changes in these countries, such as increase and aging of the population, the trends in mortality from CVD have been maintained with the adjustment of the coefficient for age, gender and specific disease (IHD or CBVD). 9 Our study showed significant and constant reduction in the mortality from CBVD in the period of 1980 to 2012. This was, most likely, due to an increased facility in diagnosis and treatment of the main risk factor for such diseases -the systemic arterial hypertension (SAH). In 2013, the diagnosis of SAH was 21.2% for the population over 18 years old and >50% for individuals over 65 years old. Almost 70% of these patients with SAH had some kind of medical assistance and 36% took at least one medication for hypertension in the Brazilian government program Programa Farmácia Popular (Popular Pharmacy Program). 16 On the other hand, the complexity of the factors involved in the pathophysiology of the atherosclerosis process largely increases the challenge of preventing IHDs. SAH control has great impact on the morbidity and mortality of CBVDs, while diagnosis and treatment of IHDs involve other risk factors, such as dyslipidemia, smoking, and diabetes, many times unknown until the first coronary event. Associated to the complexity of clinical treatment, there is the limited availability of interventional treatment, restricted to large urban centers. The result is the big heterogeneity of the risk of death from acute myocardial infarction in the different regions of Brazil. 17 However, in the period between 2007 and 2012, the justifications for a halt in the downward trend in mortality from IHD are unknown. Socioeconomic aspects and decreased access to adequate healthcare system by the less privileged population for diagnosis and treatment of IHDs may Table 1
Half of the causes of death from CVD, before 65 years of age, can be attributed to poverty. Likewise, low levels of education contribute to poverty, which further increases the rate of mortality from CVD. Malnourishment, little physical activity, alcohol consumption and smoking are other important risk factors for CVD, and are more prevalent in less privileged layers of the population. 23   trend in mortality from CVD. Environmental, occupational, behavioral and metabolic factors were responsible for almost 90% of disability-adjusted life years (DALYs) and deaths from CVD. 25 The limitations of this study relate to the quality of the Brazilian data about mortality, such as errors related to diagnosis and precision of death certificates, deaths associated with unknown causes and data entry errors. The number of death certificates containing a diagnosis for the cause of death, such as poorly defined symptoms, signs and health conditions is an indirect indicator of the standard quality of data. These certificates, despite progressive improvement, are still significant in the Northeast, north and Midwest regions in Brazil, but not in the South or Southeast. [26][27] Validation studies for the data about mortality are not available in the majority of states and cities in Brazil.

Conclusion
As opposed to CBVD, the trend in mortality from IHD stopped going down in Brazil in the last six years. It is necessary to intensify healthcare policies about the control of the main risk factors so as to reinstate the downward trend in mortality rate from IHD.

Potential Conflict of Interest
No potential conflict of interest relevant to this article was reported.

Sources of Funding
There were no external funding sources for this study.

Study Association
This study is not associated with any thesis or dissertation work.