Total cholesterol and mortality in patients with pre-existing coronary artery disease.

ABSTRACT

BACKGROUND. A positive correlation exists between serum cholesterol levels and cardiovascular mortality. However, the role of serum cholesterol in persons with pre-existing coronary artery disease is not clear. METHODS. A cohort of 524 patients with coronary artery disease was divided into four groups based on the total serum cholesterol values. Group I consisted of 68 patients with cholesterol levels of 200 mg/dl or less; Group II of 116 patients with cholesterol levels between 201 and 220 mg/dl; Group III of 187 patients with levels between 221 and 240 mg/dl and Group IV of 153 patients with cholesterol levels greater than 240 mg/dl. RESULTS. Actuarial survival analysis over an 11-year follow up did not show any overall difference in mortality between these groups (Logrank test statistic = 1.89, p > 0.1). Analysis after adjustment of the data also showed that mortality rates were not different (chi (2) = 4.73, p > 0.05). Hazard function analysis indicated that death rates per thousand person years of follow up were 49.97 +/- 8.4 in Group I, 41.38 +/- 8.4 in Group II, 55.39 +/- 4.4 in Group III and 45.38 +/- 6.4 in Group IV. These were also not statistically significant. Comparison of mortality rates in patients with angina pectoris and past myocardial infarction also showed similar results. CONCLUSION. Total serum cholesterol levels do not influence long term survival in patients with pre-existing coronary artery disease.