ARE HYPERTENSIVES HYPERCOAGULABLE

Angiotensin II is a prothrombotic vasoconstrictor. This study proves t hat many hypertensives are hypercoagulable and at risk for myocardial infarction. The modified recalcification time (MRT) test, used to asse ss hypercoagulability, incorporates the role of tissue factor in coagu lation by activating the monocyte with endotoxin to release latent tis sue factor. Aliquots of citrated blood obtained from hypertensives and normotensive controls were placed in two groups of vials, one with sa line (group S) and one with endotoxin (group E). All vials were incuba ted at 37-degrees-C for 2 hours, citrate neutralized with calcium chlo ride, and the MRT (in minutes) for group S (MRT S) and for group E (MR T E) was determined. Mean MRT S values +/- standard deviation (SD) for hypertensives (n = 25) and for controls (n = 27) were 6.4 +/- 1.2 and 6.8 +/- 1.2, respectively. The MRT E values were 4.3 +/- 1.2 and 5.7 +/- 0.9 for the hypertensives and controls, respectively. The MRT E, n ot the MRT S, was significant. Hypertensives had MRT E values <4.5 min utes, and by our established criteria, were hypercoagulable. We conclu de that because hypercoagulability is a risk factor for thrombosis, hy pertensives with short MRT E values may be at increased risk for myoca rdial or other thrombotic events.