Young infarct patients with single-vessel occlusion do not have an underlying prothrombotic state to explain their coronary occlusion.

To determine the importance of a prothrombotic state in the pathogenesis of coronary occlusion in young infarct patients, assessment of risk factor profile and thrombotic tendency was undertaken in 25 young male patients (age less than 45 yr) who were shown at angiography, following myocardial infarction, to have occlusion of a single coronary. Comparison was made with a control group of symptomatic males aged greater than 55 yr, who at angiography had significant disease in two or more coronary arteries (multi-vessel disease control group). At the time of the study more patients in the single-vessel disease study group smoked cigarettes (n = 12) compared to the control group (n = 5) (p less than 0.01). Serum cholesterol and triglycerides were higher, and high density lipoprotein-cholesterol lower, in the single-vessel disease group but the difference reached significance only with the high density lipoprotein-cholesterol. Quantitative platelet aggregability was similar in the two groups. Although the level of beta-thromboglobulin, was higher in the single-vessel disease study group the difference was not significant. There were also no significant differences between these groups in levels of fibrinogen, Factor XII and alpha-2 antiplasmin. Patients in the multi-vessel disease group, however, had increased Factor VII levels (p less than 0.01). There were no significant differences between the two groups in fibrinolytic potential or in levels of antithrombin III. Coronary occlusion in the young appears likely to be due primarily to an arterial (plaque) related event as opposed to an abnormal coagulation response to minor arterial plaque damage.