Background: There is little reliable population-based information about the distribution of risk factors among the various ischemic stroke subtypes, even though determining risk factor profiles is of major importance to develop targeted preventive strategies.
Methods: We established the distribution of first-ever ischemic stroke subtypes in a prospective population-based study conducted in Dijon, France (152,606 inhabitants). Cases were collected between January 2005 and December 2006, and were classified using TOAST classification. Vascular risk factors were recorded to determine a risk factor profile for each subtype.
Results: 332 patients with first-ever ischemic stroke (150 men and 182 women) were recorded. Adjusted-incidence to World population was 54/100,000/year. The distribution of ischemic stroke subtypes was as follows: 119 (35.8%) cases of large artery atherosclerosis, 89 (26.8%) small artery occlusions, 81 (24.4%) cardioembolisms, 43 (13%) other and undetermined causes. The most frequent vascular risk factor was hypertension, whatever the ischemic stroke subtype, with a total prevalence of 62%. Using multivariate regression we demonstrated a positive association between cardioembolism and age (OR, 1.051; 95% CI, 1.026-1.076; P<0.001) and between small artery occlusion and either high blood pressure (OR, 1.86; 95% CI, 1.06-3.27; P=0.03) or hypercholesterolemia (OR, 2.23; 95% CI, 1.33-3.76; P=0.02).
Conclusion: We demonstrate, in a comprehensive prospective population-based study, that vascular risk factors exhibit a particular distribution according to the ischemic stroke subtypes. These findings, as well as the great frequency of hypertension among stroke patients, have implications for prevention strategies, the design of clinical trials, and the organization of health care services.