Plasma beta-thromboglobulin in patients with valvular heart disease with or without valve replacement: relationship with thromboembolic accidents.

Plasma beta-thromboglobulin (BTG) was measured in 132 patients with valvular heart disease: 43 were studied before, 89 after surgery (78 mechanical valves and 11 bioprostheses). In this group of 89 selected patients, a history of thromboembolism was present in 53 (5 of them had bioprosthesis). Some abnormalities have been observed in patients with valvular heart disease as compared with controls: decreased platelet count and retention on glass column, and increased BTG. There is no statistically significant difference in BTG level between patients with (m +/- SD: 62.4 +/- 42.0 ng ml-1), or without (59.5 +/- 41.0 ng ml-1) a prosthesis; in the small series of 11 patients with a bioprosthesis, BTG was slightly lower than in other patients (44.5 +/- 14.1 ng ml-1), but still higher than in controls (26.8 +/- 13.3 ng ml-1). In the patients with a history of thromboembolism, BTG was significantly higher (66.7 +/- 47.9 ng ml-1 than in patients without this complication (49.9 +/- 21.0 ng ml-1). Thus, BTG evaluation may have some value in valvular heart disease but, at present, it should be confined to systematic research including prospective studies.