Plasma Concentrations of Platelet-Specific Proteins in Coronary Artery Disease

Abstract

The plasma concentrations of β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were measured in 100 patients with documented coronary artery disease (CAD) and in 40 controls. 18 patients had had coronary artery bypass surgery (CABS), 25 patients were on therapy with β-blocking agents and 19 were treated with oral anticoagulants. 38 patients with CAD received neither CABS nor β-blocking or anticoagulating drugs. The highest plasma concentrations of β-TG and PF4 were found in the patient group without medical or surgical treatment (patients versus controls: p < 0.01). Patients with CABS showed β-TG and PF4 levels within the normal range. Patients with β-blocking agents also had lower β-TG and PF4 values than the patient group without therapy (p < 0.05). By contrast, patients on oral anticoagulation therapy presented with similar plasma concentrations of β-TG and PF4 as untreated patients. Our data indicate that surgical or medical treatment with β-blocking agents, but not with oral anticoagulants, may have some influence on platelet function in patients with CAD. β-TG and PF4 radioimmunoassay may be a simple method to study platelet involvement in various diseases and to evaluate possible influences of medical or surgical treatment on in vivo platelet function.

Platelet Function in Patients with Chronic Coronary Heart Disease on Long-Term Anticoagulant Therapy: Effect of Anticoagulant Stopping

“…Nevertheless, and in accordance with other authors [19], in a certain percent age of these patients (41%) pTG levels over lapped with the values of the normal popula tion. In patients on ACT with an adequate level of hypocoagulability we have also found high levels of circulating PTG, which is in accordance with the results of Miihlhauser et al [22] in coronary artery disease patients. Since the pTG levels in CHD patients are high, both with and without ACT, it could be assumed that the increase in pTG is second ary to an 'in vivo' platelet activation which is not essentially affected by oral anticoagula tion.…”

Platelet-Released Proteins as Molecular Markers for the Activation Process

“…4,37,70,99 The underlying reasons for this apparent contradiction are based fundamentally on the nature of the subjects included in the original studies, 60,86 the small number of participants in the sample sizes, 2 the short-term versus long-term significance of elevated levels of either protein, 58,89 and the lack of contributing complications in the patients included in these studies. 77,108 It seems safe to state that elevations of PF4 or BTG are not good indicators of myocardial ischemia, nor is their normal plasma level to be interpreted as an indication of the absence of myocardial complications. 110 In one such study, the levels of PF4 and BTG were found to be slightly more increased in normal age-and sex-matched subjects 57 than was found in ischemic subjects, and this mild transient elevation correlated best with the plasma catecholamine changes.…”