Country of birth and risk of hospitalization due to heart failure: a Swedish population-based cohort study

To explore the relation between country of birth and risk of hospitalization due to heart failure (HF). All 40-89 year-old inhabitants in the city of Malmo, Sweden (n = 114,917, of whom 15.2% were born outside Sweden) were followed from November 1st, 1990 until December 31st, 2007. During a mean follow-up of 13.5 +/- A 5.3 years, a total of 7,640 individuals (47.4% men) were discharged from hospital with first-ever HF as primary diagnosis. Of them, 1,243 individuals had myocardial infarction (MI) before or concurrent with the HF hospitalization. The risk of HF was compared between immigrants from selected countries and Swedish natives. The overall analysis showed substantial differences among immigrant groups (P < 0.001). Compared to Swedish natives, significantly increased HF risk was found among immigrants from Finland (HR (hazard ratio): 1.40; 95% CI, 1.10-1.81), Former Yugoslavia (1.45: 1.23-1.72) and Hungary (1.48: 1.16-1.89), taking age, sex, marital status, annual income and housing condition into account. Analysis results were similar when cases with MI before or concurrent with the HF hospitalization were included in the analysis. In general, the risk of HF was significantly higher among immigrants from high-income and middle-income countries. Marital status, annual income and housing condition were also significant independent risk factors for HF in this population. There are substantial differences in risk of hospitalization due to HF among immigrants from different countries that can not be explained by socioeconomic factors. To what extent these differences could be explained by biological risk factors remains to be explored.