Global mortality variations in patients with heart failure:udresults from the International Congestive Heart Failureud(INTER-CHF) prospective cohort study

摘要

Background Most data on mortality and prognostic factors in patients with heart failure come from North Americaudand Europe, with little information from other regions. Here, in the International Congestive Heart Failure (INTERCHF)udstudy, we aimed to measure mortality at 1 year in patients with heart failure in Africa, China, India, the MiddleudEast, southeast Asia and South America; we also explored demographic, clinical, and socioeconomic variablesudassociated with mortality.udMethods We enrolled consecutive patients with heart failure (3695 [66%] clinic outpatients, 2105 [34%] hospital inudpatients) from 108 centres in six geographical regions. We recorded baseline demographic and clinical characteristicsudand followed up patients at 6 months and 1 year from enrolment to record symptoms, medications, and outcomes.udTime to death was studied with Cox proportional hazards models adjusted for demographic and clinical variables,udmedications, socioeconomic variables, and region. We used the explained risk statistic to calculate the relativeudcontribution of each level of adjustment to the risk of death.udFindings We enrolled 5823 patients within 1 year (with 98% follow-up). Overall mortality was 16·5%: highest in Africaud(34%) and India (23%), intermediate in southeast Asia (15%), and lowest in China (7%), South America (9%), and theudMiddle East (9%). Regional differences persisted after multivariable adjustment. Independent predictors of mortalityudincluded cardiac variables (New York Heart Association Functional Class III or IV, previous admission for heartudfailure, and valve disease) and non-cardiac variables (body-mass index, chronic kidney disease, and chronic obstructiveudpulmonary disease). 46% of mortality risk was explained by multivariable modelling with these variables; however,udthe remainder was unexplained.udInterpretation Marked regional differences in mortality in patients with heart failure persisted after multivariableudadjustment for cardiac and non-cardiac factors. Therefore, variations in mortality between regions could be the resultudof health-care infrastructure, quality and access, or environmental and genetic factors. Further studies in large, globaludcohorts are needed.