[The red blood cell aggregation in men with coronary risk factors]

1. The in vitro test for red blood cell aggregation has been improved, the coefficient of variation was decreased to 14.2%. 2. By the improved method the earlier findings were confirmed with high statistical significance that heavy smokers have a significantly higher red blood cell aggregation value in comparison with nonsmokers. 3. It could be shown that other coronary risk factors, especially hypercholesterolaemia, increase the aggregation value too. 4. The aggregation of red blood cells increases in the presence of several coronary risk factors in the same patient to higher values than expected from the addition of the aggregations caused by single risk factors.