Seasonal variation and trends in heart failure morbidity and mortality in a South American community hospital.

Circannual variation in cardiovascular events is well-known. Seasonal variation (SV) in heart failure (HF) has been described in the Northern Hemisphere, but there is scarcity of data in South America. The goals of the present study were to (1) describe the SV of admissions and deaths for HF, and (2) describe trends in HF morbidity and mortality in a community hospital in Argentina from 1992 to 1999. The study sample included 6369 admissions. During this period, the number of HF admissions rose by 188% and the rate HF admissions/all admissions increased from 3.28% to 7.84%. In-hospital mortality decreased from 21% to 13%. HF admissions followed a seasonal pattern with a winter-spring predominance. Male and very old patients were the subgroups with the highest SV. The authors identified clear SV in HF deaths and admissions, which raises a different hypothesis about the rationale of HF admissions and provides information for the organization of care and resource allocation.