leukotriene-e4 and Coronary-Restenosis

Leukotrienes are potent inflammatory mediators synthesized locally within the cardiovascular system through the 5-lipoxygenase pathway of arachidonic acid metabolism. The leukotrienes, consisting of dihydroxy leukotriene LTB4 and the cysteinyl leukotrienes LTC4, LTD4 and LTE4, act by targeting cell surface receptors expressed on inflammatory cells and on structural cells of vessel walls. LTB, induces leukocyte activation and chemotaxis via high- and low-affinity receptor subtypes (BLT1 and BLT2), respectively. Recently, BLT, receptors were found on human vascular smooth muscle cells, inducing their migration and proliferation. Cysteinyl leukotrienes are vasoconstrictors and induce endothelium-dependent vascular responses through the CysLT, and CysLT2 receptor subtypes. There is also pharmacological evidence for the existence of further CysLT receptor subtypes. Taken together, experimental and genetic studies suggest a major role of leukotrienes in atherosclerosis and in its ischemic complications such as acute coronary syndromes and stroke. Furthermore, the effects on vascular smooth muscle cells suggest a role in the vascular remodeling observed after coronary angioplasty, as well as in aortic aneurysm. Further experimental and clinical studies are needed to determine the potential of therapeutic strategies targeting the leukotriene pathway in cardiovascular disease.

Topics: Angioplasty, Balloon, Coronary; Animals; Aortic Aneurysm; Arachidonic Acid; Atherosclerosis; Cardiovascular Diseases; Cell Movement; Coronary Restenosis; Disease Models, Animal; Guinea Pigs; Humans; Hypertension; Leukotriene Antagonists; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Mice; Muscle, Smooth, Vascular; Rats; Receptors, Leukotriene; Stroke

Treatment of severe peripheral arterial occlusive disease requires percutaneous revascularization. However, little is known about risk factors or predictors for reocclusion/restenosis. Cysteinyl leukotrienes are highly bioactive lipid mediators of inflammation. Their intravascular production may take place in the atheromatous plaque or result from interaction within activated leukocyte-platelet aggregates.. We prospectively measured urinary leukotriene E4, the main end-metabolite of cysteinyl leukotrienes in a group of 179 subjects with peripheral artery occlusive disease of the lower extremities. At the enrollment to the study, 22.9% had angioplasty and the remaining had angioplasty with stent implantation. During 12-month follow-up, 29.6% developed reocclusion/restenosis despite a standard pharmacotherapy. We evaluated treatment outcomes at 1, 3, 6 and 12-month follow-up visits, along with urinary leukotriene E4 excretion.. During the study period, we observed a linear increase of urinary leukotriene E4 excretion only in subjects whose lower limb ischemia worsened. Moreover, elevated leukotriene E4 in urine was found only in subjects who developed reocclusion/restenosis. This was significant not only as a coincidence at the time of the follow-up visit, but leukotriene E4 elevation preceded clinical manifestation of reocclusion/restenosis.. Our results demonstrated that serial measurements of urinary leukotriene E4 allowed to predict failure of angioplasty with/or without stent implantation for peripheral artery occlusive disease. However, to prove causality between cysteinyl leukotrienes overproduction and occlusive lower limb ischemia, a clinical trial with leukotrienes modifying drugs would be required.

Topics: Aged; Angioplasty; Arterial Occlusive Diseases; Biomarkers; Coronary Restenosis; Cysteine; Female; Follow-Up Studies; Humans; Ischemia; Leukotriene E4; Leukotrienes; Male; Middle Aged; Peripheral Arterial Disease; Prospective Studies; Time Factors