Ischemic heart disease-related mortality in Brazil, 2006 to 2020. A study of multiple causes of death.

Context: Both the aging of the population and the increase in noncommunicable diseases may influence the progression and outcomes culminating in death, changing the evolution of ischemic heart diseases (IHDs) and their associated causes. Using the multiple causes of death method could help understand the magnitude of these relationships and enable better targeting of investments in health.

Objectives: To evaluate the mortality from IHD in Brazil between 2006 and 2020 using the method of multiple causes and identify differences in the distribution pattern of IHD mortality by sex and geographic region.

Methods: Based on information extracted from death certificates (DCs) obtained from the database of the Department of Informatics of the Unified Health System (DATASUS), we used the multiple causes method to analyze the causes of death associated with IHD when IHD was defined as the underlying cause of death (UC) and the causes of death listed as the UC when IHD was recorded in any other lines of the DC, from 2006 to 2020, in Brazil. Subsequently, the proportion of these causes of death and differences between sexes and geographic regions were evaluated, with statistical relevance analyzed using the chi-square test, and the dependence between factors illustrated using stacked bar charts and small-world network graphs.

Results: When IHD was listed as the UC of death, the most frequent associated causes of death were, in descending order of frequency, acute myocardial infarction (AMI), arterial hypertension (AH), chronic ischemic heart disease (CHID), heart failure (HF), and diabetes mellitus (DM). When IHD was mentioned in any line of the DC, the most frequent UCs of death were AMI followed by DM, CIHD, chronic obstructive pulmonary disease (COPD), stroke, dyslipidemia, and, in the year 2020, COVID-19. The most frequent cause of death in women were DM as the UC and associated cause of death, AH as the UC, and CIHD and Alzheimer's disease as associated causes of death, while the most frequent causes of death in men were substance dependence as the UC and associated cause of death, and cancer as an associated cause of death. The most frequent causes of death were DM and stroke in the North and Northeast, dyslipidemia and obesity in the Midwest, Alzheimer's disease in the South and Southeast, and atherosclerotic heart disease (AHD) and COPD in the South.

Conclusions: Several diseases - including AMI, AH, CIHD, HF, and DM - were the most frequent associated causes of death when IHD was recorded as the UC. In contrast, AMI, DM, CIHD, COPD, and stroke were the most frequent UCs when IHD was listed as an associated cause of death. The degree of these associations varied between sexes and geographic regions.