Is immigration associated with an increase in risk factors and mortality among coronary artery disease patients? A cohort study of 13,742 patients

Clinical studies showing an association between immigration and increased prevalence of coronary risk factors or mortality rate in patients with coronary artery disease are scarce. To compare the risk profile and mortality of coronary patients born in Israel with those who immigrated to Israel, and to determine whether recent immigration is associated with greater risk among immigrants from the Soviet Union. Demographic, clinical, and laboratory data were collected on chronic coronary artery disease patients from 18 Israeli medical centers during the screening period of the Bezafibrate Infarction Prevention Study in the early 1990s. Data on mortality after a mean 7.7 year follow-up were obtained from the Israel Population Registry. While significant differences in mortality (14.7% vs. 18.5%, P < 0.001) were observed between Israeli-born patients and immigrants respectively, the mortality in these groups was similar when compared within specific age groups. Immigrants suffered more from hypertension and angina pectoris, and their New York Heart Association functional limitation class was higher, as compared to their Israeli-born counterparts. A multivariate analysis of mortality comparing patients from the Soviet Union who immigrated after 1970 with those who immigrated before 1970 showed an increased risk for newer immigrants, with a hazard ratio of 1.69 (95% confidence interval 1.19-2.40) for those immigrating between 1970 and 1984, and 1.68 (95% CI 1.01-2.28) for those immigrating between 1985 and 1991. The worse profile and prognosis observed among patients who recently emigrated from the Soviet Union cannot be explained by traditional risk factors for CAD such as smoking, diabetes, hypertension, and lipid disorders. Further investigation, including variables such as psychological stress to which immigrants are more exposed than others, is needed.