Risk Evaluation of Coronary Heart Disease and Cerebrovascular Disease by the Japan Atherosclerosis Society Guidelines 2002 Using the Cohort of the Holicos-PAT Study

Our purpose in this study was to evaluate the new JAS guidelines as a risk assessment tool in Japanese patients with hypercholesterolemia, using the cohort of the Holicos-PAT study. The Holicos-PAT study was designed as a prospective observational study. 2039 patients were followed with or without pravastatin for 5 years. We assessed coronary heart disease (CHD) and cerebrovascular disease (CVD) risks by the patient categories described in the JAS guidelines. In the Holicos-PAT study, the primary endpoints were CHD, and the secondary endpoints were CVD and total mortality. CHD event includes onset and worsening of angina pectoris, performing CABG or PTCA, non-fatal and fatal myocardial infarction, and death from CHD including heart death and sudden death. CVD events are onset or recurrence of cerebral infarction, onset of cerebral hemorrhage, and death from cerebral infarction or hemorrhage. The event rates were calculated by the person-years method, and the differences in event rates between category groups were analyzed by chi-square test. The event rates of CHD in Category A, B1, B2, B3, B4 and C, were 1.1, 4.0, 2.8, 5.7, 18.2 and 38.8 per 1,000 person-years. The rates of CHD events in the higher risk category groups, Category B4 group (p = 0.004 in whole patients) and C group (p < 0.001 in whole patients), were significantly higher than that in the combined category groups A + B1 + B2. The event rates of CVD in Category A, B1, B2, B3, B4 and C, were 2.1, 1.8, 1.8, 0.6, 10.8 and 6.4 per 1,000 person-years. The event rates of CHD in men were significantly higher than those in women, in categories B4 (p < 0.001) and C (p < 0.001). From these results, each category classified by accumulation of risk factors, showed increasing event rates of CHD and CVD. The categories in the JAS guidelines are useful to assess CHD and CVD risk in Japanese patients with hypercholesterolemia. However, the risk evaluation by the JAS guideline categories may underestimate the risk in men and overestimate it in women.