''Thick'' blood causes as well as protects from heart attack, stroke

''Thick'' blood causes as well as protects from heart attack, strokeWashington, Aug 25 : Animal studies carried out by researchers at Heidelberg University Hospital have shown that "thick" blood can not only cause heart attack and stroke, but also prevent them.

In their study report, the scientists say that mice with a greater tendency to form blood clots have larger plaques in their vessels, but they are more stable.

Thus, there is less risk that these plaques will rupture and obstruct circulation.

Usually, the more blood coagulates, the greater is the risk of vascular obstruction, and anticoagulants are used to protect against these complications.

However, clinical studies have thus far not proven that an increased clotting tendency also has a detrimental effect for plaque development.

Led by Dr. Berend Isermann, the researchers examined mice with elevated blood fat levels, and a genetic defect that leads to an increase in blood clotting.

They found that the mice developed larger plaques than those without the genetic defect, but the plaques were more stable.

In addition, no vascular obstruction was observed, as the vascular wall expanded to adapt to the new situation.

The negative effect of larger plaques on circulation was compensated by the positive effect of stability and a greater vessel diameter.

However, the long-term use of anticoagulants (in this case, low molecular weight heparin) reversed these advantages- the size of the plaques was reduced, but stability was lost, increasing the risk of complications.

"Our findings were made on mice, but they confirm the results of clinical studies on humans. In addition, in vitro studies show that human cells react similarly to mouse cells," said Isermann.

The team assumed that the results could be transferred to humans and recommends weighing the advantages and disadvantages of anticoagulants carefully before administering them to a patient.

"Currently, there is no indication that these new observations also apply to drugs that inhibit the function of platelets," said Isermann.

When deciding on therapy, the cause of the coagulation disorder and the degree of already existing atherosclerosis should be taken into consideration.

Additionally, the researchers recommended using anticoagulants that inhibit specific coagulation factors in order to preserve the positive effects on plaque stability.

Various new drugs that inhibit specific coagulation factors are currently being studied in clinical trials.

"It is important that plaque stability and the influence on atherogenesis are also studied in these trials," said Isermann.

The study has been published in the journal Circulation. (ANI)