Risk factors for primary prevention of cardiovascular disease and risk reduction by lipid control: the OMEGA study risk factor sub-analysis

To identify risk factors for cardiovascular disease (CVD) in hypertensive patients with no history of CVD being treated with antihypertensive drugs, we examined subgroup data (n = 13 052) from the prospective, observational Olmesartan Mega Study to Determine the Relationship between Cardiovascular Endpoints and Blood Pressure Goal Achievement (OMEGA) study. Risk factors for CVD, stroke and coronary heart disease (CHD) were examined using a Cox proportional hazards model. In addition, the effect of statin therapy at baseline on CHD prevention was analyzed in dyslipidemic patients. The factors significantly related to CVD were female (hazard ratio [HR] = 0.637, 95% confidence interval [CI] 0.428-0.948), older age (65-69 years: HR = 2.165, 95% CI 1.214-3.861; 70-74 years: HR = 2.324, 95% CI 1.294-4.174; ≥75 years: HR = 2.448, 95% CI 1.309-4.578), family history of CHD (HR = 1.993, 95% CI 1.249-3.179), diabetes (HR = 2.287, 95% CI 1.700-3.078), current smoking (HR = 2.289, 95% CI 1.512-3.466) and alcohol drinking socially (HR = 0.589, 95% CI 0.379-0.913). Diabetes was a risk factor for both stroke and CHD, while age, family history of CHD, and sodium intake score were risk factors for stroke alone. Sex, dyslipidemia, smoking and exercise habits were risk factors for CHD alone. The risk of CHD in dyslipidemic patients on statin treatment was comparable to the risk in patients without dyslipidemia (HR = 1.134, 95% CI 0.604-2.126). However, in dyslipidemic patients not on statin treatment, the HR increased to 1.807 (95% CI 1.156-2.825). In conclusion, some risk factors for CVD in hypertensive patients being treated with antihypertensive drugs with no history of CVD differed between CHD and stroke. These results suggest the importance of managing dyslipidemia with a statin for primary prevention of CHD, as well as the importance of hypertension therapy.