Time course of reendothelialization of stents in a normal coronary swine model: characterization and quantification

Late thrombosis of coronary drug-eluting stents is an infrequent but serious complication of percutaneous transluminal coronary angioplasty. The best predictor of this event is the lack of endothelialization of stent struts. The objective of this study is to characterize and quantify the time course of endothelialization of different stents implanted in nonatherosclerotic swine coronary arteries. Thirty-three Carbofilm-coated stents were implanted percutaneously in 11 anesthetized domestic, crossbred pigs (weight 25 ± 3 kg, 2 months old). Each animal received 1 stainless steel stent (SS), 1 cobalt-chromium stent (CCS), and 1 tacrolimus-eluting stent (TES) in each coronary artery. Follow-up periods were 1 day (n = 9 stents), 3 days (n = 9 stents), and 7 days (n = 15 stents). Longitudinal sections of the stented vessels were examined using scanning electron microscopy. At 1 day, there was scarce, patchy endothelialization with areas of fibrin; the endothelialization rate was similar for all the stents (SS, 29% ± 23%; CCS, 29% ± 24%; TES, 31% ± 25%; P = .9). At 3 days, there were more endothelial cells but with immature features and giant cells over fibrin; the endothelialization was greater in SS and CCS than in TES (SS, 79% ± 14%; CCS, 81% ± 17%; TES, 46% ± 9%; P = .007). At 7 days, arteries showed better endothelialization with few giant cells; the endothelialization was greater in SS and CCS than in TES (SS, 95% ± 4%; CCS, 98% ± 4%; TES, 79% ± 9%; P = .01). In conclusion, the described model is useful for the analysis of endothelialization of coronary stents and facilitates measurement of its rate of formation and characterization of the involved cell types.

Plasma leukocyte elastase concentration in angiographically diagnosed coronary artery disease

OBJECTIVE

To evaluate the clinical usefulness of leukocyte elastase determination in the diagnosis of coronary artery disease (CAD).

BACKGROUND

Recent research has shown the important role of elastase, a proteolytic enzyme released by neutrophils, in the pathogenesis of CAD.

METHODS

141 patients underwent coronary angiography during investigation of chest pain and/or heart valve disease. Ninety-six had coronary lesions and 45 non-stenotic coronaries. The patients were characterized as regards presence or absence of angina (stable or unstable), family history of CAD, smoking, diabetes mellitus, hypertension, leukocyte counts, and plasma lipid and elastase concentrations. Among CAD-group patients, those with simple atheromatous plaques were distinguished from those with complex plaques.

RESULTS

Elastase concentrations were greater in the CAD group than in the non-CAD group (49.7 +/- 2.8 micrograms.l-1; as against 29.5 +/- 2.2 micrograms.l-1; P < 0.001), and greater among complex-plaque CAD patients than among simple-plaque CAD patients (65.2 +/- 5.3 micrograms.l-1 as against 38.6 +/- 1.9 micrograms.l-1; P < 0.001). Logistic regression analysis showed (a) that the risk of CAD varied with elastase concentration, angina status, age and sex, increasing by 11% for every 1 microgram.l-1 increase in elastase concentration; and (b) that among CAD patients the risk of complex plaques was greatest for those with unstable angina and high elastase concentration, increasing by 6% for every 1 microgram.l-1 increase in elastase concentration.

CONCLUSIONS

Peripheral blood leukocyte elastase concentration is a sensitive diagnostic marker of CAD. High values suggest the presence of complex atheromatous plaques.

Activity of leucocyte elastase in women with coronary artery disease documented using angiography

BACKGROUND

Recent studies suggest that leucocyte elastase is involved in the pathogenesis of atherosclerosis. The objective of this study was to characterize the role of leucocyte elastase in arterial disease in women.

METHODS

Forty-two women underwent coronary angiography because of chest pain or valvulopathy. Twenty-three showed no signs of lesions (group 1) and 19 had coronary stenosis (group 2). Their age, weight and height were recorded, together with the presence of angina, arterial hypertension, diabetes mellitus, any family history of coronary disease and levels of tobacco consumption. Leucocyte counts, lipid levels and neutrophil elastase concentrations were determined from peripheral blood samples.

RESULTS

Levels of elastase were found to be significantly higher in group 2 than in group 1 (mean +/- SD 53.3 +/- 15.9 compared with 28.6 +/- 16.8 micrograms/l, P < 0.01). Patients from group 2, who had a greater mean age (69 +/- 7 compared with 58 +/- 9 years for group 1, p < 0.001), were more often diabetic (26% compared with 0%, p < 0.05) and were more likely to have family histories of ischaemic cardiomyopathy (59% compared with 18%, P < 0.05). However, multivariate analysis indicated that age and elastase levels were of independent value as predictors of coronary artery disease.

CONCLUSION

The concentration of elastase in peripheral blood is higher in women who have stenosis on coronary angiography.