Prevalence and outcomes of American Heart Association stages of heart failure in an adult brazilian population of the ELSA-Brasil study

Abstract

Abstract Aims Heart failure (HF) has a major impact on public health, affecting up to 2% of adult population. HF staging is helpful in capturing pre-clinical disease and its progression to advanced stages. We aimed to determine the prevalence and mortality of HF stages in the participants of a Brazilian adult cohort. Methods The ELSA-Brasil cohort comprises 15,105 adult public servants from 6 Brazilian capitals. In the initial evaluation of the study (2008-2010), ELSA carried out interviews and clinical, laboratory, and cardiovascular ancillary tests. In this analysis, we included participants who had electrocardiogram and echocardiogram performed at baseline visit, and additional information regarding risk factors and functional capacity. The HF stages were defined based on AHA guidelines criteria as follow: Stage 0 was defined as a healthy individual with no risk factors for heart failure. Stage A (at risk for HF) included those without cardiac structural or functional abnormality but with any of the following conditions: systemic hypertension; diabetes mellitus, obesity, history of myocardial revascularization, history of rheumatic fever, and seropositivity for Chagas’ disease. Stage B (pre-HF) was defined as asymptomatic participants with history of myocardial infarction or any major abnormalities on ECG or echocardiogram. Stage C (symptomatic HF) included participants with a clinical history of HF, or HF symptoms in the presence of structural heart disease (defined as in Pre-HF stage). Considering the community-dwelling profile of the sample, we did not expect to have advanced heart failure patients in our sample. Results We included the 3,267 participants (61±9 years; 53% women) with baseline data. Prevalences of HF stages were stage 0: 938 (29%) A: 1,385 (42%), B: 651 (28%) and C: 293 (9%), with different distribution between sexes (p<0.001). Older participants had higher prevalences of stages B and C (p<0.001), with the prevalence of stage C increasing from 1.8% at 35-44 years to 12.2% at 65-74 years. After 12 years of follow-up, total mortality rates of HF stages were Stage 0: 4%; A:10%. B: 16%, and C: 26%, and respective Cox proportional hazard ratios [95% CI] adjusted for age and sex were A: 1.94 [1.3-2.8], B:2.78 [1.9-4.1], and C: 5.39 [3.6-8.1] compared to stage 0. Conclusions The prevalence of HF in Brazilians reflects what is described in international literature, with a large proportion of individuals in pre-symptomatic stages. A notable shift in the sample toward pre-symptomatic and symptomatic HF occurred gradually and persistently across the age span studied. Mortality rates increase incrementally across the HF stages. This information is important for understanding and planning health policies for this syndrome.