Hostility Is Associated With Increased Platelet Activation in Coronary Heart Disease

OBJECTIVE: To determine whether Potential for Hostility is related to platelet activation (PA) among patients with coronary heart disease (CHD) and healthy controls. Increased PA has been associated with adverse secondary events after myocardial infarction or coronary angioplasty. METHODS: We tested 32 CHD patients and 23 healthy men and women, aged 45 to 73 years, for PA by using whole blood flow cytometry. PA was measured in blood exiting a bleeding time wound (wound-induced platelet activation) and also in venous blood stimulated in vitro with collagen. Monoclonal antibodies were used to test for fibrinogen receptor activation and fibrinogen receptor binding. All subjects refrained from taking aspirin for at least 14 days before testing; CHD patients stopped nitrates and calcium channel blockers for 24 hours, while continuing to take lipid-lowering medications. Potential for Hostility was assessed, using the Type A Structured Interview. RESULTS: Among the CHD patients only, all four of the wound-induced fibrinogen receptor activation indicators (activation and binding) were related to hostility; the relationships were significant for receptor activation at 2 minutes, and for receptor binding at 1 minute (r values = .46, p values = .02). Subjects on lipid-lowering medications had lower PA for most measures. Healthy subjects had higher wound-induced fibrinogen receptor activation at 2 minutes and fibrinogen receptor activation in vitro than the CHD patients (p = .04), but after statistical adjustment for lipid-lowering medications, there were no significant differences between the patients and controls. CONCLUSIONS: PA was related to hostility among CHD patients, consistent with previous studies indicating a relationship between PA and psychological factors among CHD patients. However, PA was not increased in nonsmoking, nondepressed CHD patients relative to controls.