Seasonal variation of decompensated heart failure admissions and mortality rates in sub-Saharan Africa, Cameroon

Abstract Background Decompensated heart failure (HF) and related deaths are common in cardiology units. Epidemiological data in north hemisphere suggest higher rates during winter. Objective We aimed to describe the seasonal variation of decompensated HF admission and mortality rates in a country with equatorial climate. Methods We conducted a retrospective cross-sectional study from 2016 to 2018 in cardiology unit of the Yaoundé Central Hospital, collecting data on HF morbidity and mortality from registers and patients’ files. Climate data of the corresponding period were obtained from the meteorology office of the Cameroonian ministry of transports. Analysis of variance and Chi square test were respectively used to compare the continuous and categorical data between seasons. Correlation between continuous data was assess with the Pearson correlation coefficient. Results Of the 1,755 patients admitted in the unit during the study period, 636 (36.2%) had decompensated HF, among which 115 (18%) died. Decompensated HF admission, mortality and lethality rates – respectively 38.2%, 6.7% and 17.9%- were higher during long rainy season (p > 0.05). We observed an inverse linear correlation between monthly temperatures and admission rate (r = -0.301; p = 0.070), lethality rate (r = − 0.361; p = 0.030) and mortality rate (r = − 0.385; p = 0.020). There was no significant difference of the distribution of precipitating factors between seasons. Conclusion Decompensated HF admissions and deaths increases in rainy season where the temperature is lower. This suggest a need of effective methods to mitigate the effect of cold on cardiovascular diseases.