To the Editor.
—The results of clinical studies correlating lipoprotein levels with risk for thrombotic events like myocardial infarction are inconsistent and not sensitive indicators of risk.1 One may assume that these thrombotic events are causally related to hypercoagulability and that protection from these events is associated with relative hypocoagulability. Regrettably, there is no coagulation test to detect a prothrombotic (high-risk) state or antithrombotic (low-risk) state as a marker of the effects of lipoproteins.We here describe the utilization of a modified recalcification time (MRT) test to document the adverse coagulation-accelerating effect of low-density lipoproteins (LDLs) and the beneficial coagulation-retarding property of high-density lipoproteins (HDLs). This test was described in detail in a recent article.2 Unlike other tests, by using whole blood, the MRT incorporates the role of both cellular and chemical participants in coagulation. Also, incubating blood with an activator like a lipoprotein induces the monocyte to