Activation of the contact system and inflammation after thrombolytic therapy in patients with acute myocardial infarction

Piera Angelica Merlini, Massimo Cugno, Marco L. Rossi, Pietro Agricola, Alessandra Repetto, Raffaella Fetiveau, Paolo Diotallevi, Umberto Canosi, Pier Mannuccio Mannucci, Diego Ardissino

Research output: Contribution to journalArticlepeer-review


Thrombolytic therapy activates the contact system, and factor XII activation may activate the coagulation cascade and inflammation. It is not known whether an early inflammatory response is induced by thrombolytic therapy in patients with acute myocardial infarction (AMI). We prospectively measured the plasma levels of activated factor XII, cleaved kininogen, prothrombin fragment 1 + 2 (as indexes of the contact phase and coagulation activation), and interleukin-6 and C-reactive protein (CRP) (as indexes of inflammation) in 39 patients hospitalized for AMI within 12 hours of symptom onset: 26 receiving thrombolytic therapy and 13 heparin alone. Blood samples were collected at baseline and after 90 minutes and 24 hours. Patients undergoing thrombolysis had a significant early increase in activated factor XII (from 2.2 ng/ml at baseline to 4.7 ng/ml after 90 minutes; p = 0.0001), cleaved kininogen (from 26% to 37%; p = 0.001), and fragment 1 + 2 (from 1.4 to 2.1 nmol/L; p = 0.0001), whereas the 24-hour levels were similar to baseline levels. The levels of interleukin-6 significantly increased during the first 90 minutes (from 3.9 to 6.3 μg/ml; p = 0.001), and were even higher after 24 hours (11.9 ng/ml, p = 0.0001). CRP levels increased only after 24 hours (p = 0.0001). There were no changes in these parameters in patients receiving heparin alone, except for a 24-hour increase in interleukin-6 and CRP levels. Thus, in patients with AMI receiving thrombolytic therapy, early activation of inflammation parallels the activation of the contact system and the coagulation cascade, which might contribute to microvascular obstruction and reperfusion injury.

Original languageEnglish
Pages (from-to)822-825
Number of pages4
JournalThe American Journal of Cardiology
Issue number7
Publication statusPublished - Apr 1 2004

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


Dive into the research topics of 'Activation of the contact system and inflammation after thrombolytic therapy in patients with acute myocardial infarction'. Together they form a unique fingerprint.

Cite this