White blood cell count and haematocrit as predictors of coronary recurrence after myocardial infarction.

Baseline white blood cell count (WCC) and haematocrit were examined in relation to recurrent coronary events and to all-cause mortality in 2026 persons enrolled in the first Persantin-Aspirin Reinfarction Study (PARIS-1) 2-60 months after myocardial infarction. WCC was strongly related to coronary recurrence (relative risk 3.5 for men with WCC greater than or equal to 9 X 10(9)/l vs men with WCC less than 5 X 10(9)/l) and total mortality (relative risk 2.6). No such relationships were found for haematocrit. WCC correlated also with cigarette-smoking, diuretic use, serum cholesterol and uric acid; however, the associations with coronary recurrence and total mortality persisted on multiple linear and logistic regression analysis including these variables and treatment group (p less than 0.001). WCC is therefore an easily-measured prognostic variable in survivors of myocardial infarction. Furthermore, we suggest that white blood cells may promote myocardial ischaemia by capillary plugging and/or release of toxic oxygen metabolites.