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

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.