Fibrinogen, a secondary risk factor for stroke patients

Abstract

There is increasing evidence that fibrinogen represents a cardiovascular risk factor, quantitatively comparable with the established risk factors. It might play a causal role in the process of atherogenesis, although the mechanisms are not yet fully understood. Plasma fibrinogen concentrations of 625 patients with a history of stroke were determined, at the begin of their stay in a specialized German stroke rehabilitation unit. Mean time interval between the acute events and measurements was 7 months. Then they were followed up for two years. 85 re-strokes, myocardial infarctions, or cardiovascular deaths (pre-defined study endpoints) were reported. In 60 cases matched pairs could be found among the remainder with defined conformity in parameters associated with atherosclerosis: total cholesterol, triglycerides, blood glucose, gender, age, body mass index, blood pressure, smoking habits, further concomitant diseases, and time interval between stroke and measurements.

In the cross-sectional analysis all subgroups with a time interval between stroke and measurements of 60 months or less showed significantly higher fibrinogen levels (between 340 and 360 mg/dl) in comparison with a control group of the same age and similar concomitant diseases. Frequency distribution of fibrinogen levels of matched pairs and the remainder were almost identical, while almost 60% of the re-event patients were found in the highest tertile. Consequently mean values differed significantly: 344 ± 14 mg/dl for matched pairs vs. 396 ± 18 mg/ dl for re-events (p = 0.027).

Results suggest that in stroke patients high fibrinogen levels are a risk factor for a further event. Therefore it seems reasonable to include the measurement of fibrinogen into the screening program for patients at risk. Large intervention trials are required to investigate the question whether therapeutic lowering of fibrinogen has favourable effects, as theoretically suggested.

Zusammenfassung

Bei Patienten mit transitorischen ischämischen Attacken lassen sich regelmäßig pathologische Veränderungen der Blutfließeigenschaften feststellen [1, 3]. Für Patienten mit akutem Schlaganfall ist dies ebenfalls mehrfach belegt [1, 2, 6], es könnte sich aber um ein Epiphänomen im Rahmen der „Akutphasereaktion“ handeln [8]. Eine pathologische Blutrheologie könnte allerdings auch Ursache einer Minderperfusion sein und dann zu einem Schlaganfallrezidiv prädisponieren [5]. Dafür sprechen u. a. Befunde, wonach hohe Fibrinogenspiegel einen unabhängigen kardiovaskulären Risikofaktor darstellen [4, 9]. Diese Studie mit Überlebenden eines ersten Schlaganfalles sollte klären helfen, ob hämorheologischen Parametern, gemessen nach Abklingen der „Akutphasereaktion“, unabhängig von den anerkannten kardiovaskulären Risikofaktoren, prognostische Bedeutung zukommt.

deceased / verstorben