Ischemic and thrombotic effects of dilute diesel-exhaust inhalation in men with coronary heart disease

A b s t r ac t During both exposure sessions, the heart rate increased with exercise (P<0.001); the increase was similar during exposure to diesel exhaust and exposure to filtered air (P = 0.67). Exercise-induced ST-segment depression was present in all patients, but there was a greater increase in the ischemic burden during exposure to diesel exhaust (−22±4 vs. −8±6 millivolt seconds, P<0.001). Exposure to diesel exhaust did not ag- gravate preexisting vasomotor dysfunction, but it did reduce the acute release of en- dothelial tissue plasminogen activator (P = 0.009; 35% decrease in the area under the curve). Conclusions Brief exposure to dilute diesel exhaust promotes myocardial ischemia and inhibits endogenous fibrinolytic capacity in men with stable coronary heart disease. Our find- ings point to ischemic and thrombotic mechanisms that may explain in part the ob- servation that exposure to combustion-derived air pollution is associated with adverse cardiovascular events. (ClinicalTrials.gov number, NCT00437138.)