Does the level of soluble intercellular adhesion molecule 1 predict myocardial injury before cardiac markers increase?

BACKGROUND: The measurement of cardiac markers is still the gold standard for diagnosing myocardial infarction (MI), but there is always a transition period between the time of infarction and when a marker can be measured in the blood. Therefore, clinicians are shifting their focus to the identification of potential new analytes capable of predicting MIs before the standard cardiac markers increase. In this study, we tested whether measurement of the concentration of soluble intercellular adhesion molecule 1 (sICAM-1) in plasma can be used for this purpose. MATERIALS AND METHODS: In this prospective study, we included 60 male patients who had a left main coronary artery lesion or a left main equivalent and who underwent elective (group I, n = 20), urgent (group II, n = 20), or emergent (group III, n = 20) coronary artery bypass grafting (CABG). We excluded patients who had increased cardiac markers at admission, and drew blood samples for sICAM-1 measurements from other patients immediately after coronary angiography evaluations. We divided the patients into 3 groups according to their clinical characteristics and cardiac marker levels. Only patients with increased cardiac markers underwent emergent CABG (group III). We measured sICAM-1 concentrations immediately after coronary angiography and measured creatine kinase MB (CK-MB) and cardiac troponin I (cTnI) just before CABG. We then evaluated the results for correlations. RESULTS: CK-MB, cTnI, and sICAM-1 levels were significantly higher in group III than in groups I and II (P < .05 for all). Our analysis for correlations between the sICAM-1 level and cardiac marker levels revealed no significant correlations in group I (CK-MB, r = 0.241 [P = .15]; cTnI, r = -0.107 [P = .32]) and group II (CK-MB, r = -0.202 [P = .19]; cTnI, r = 0.606 [P = .002]), but our analysis did reveal highly significant correlations in group III (CK-MB, r = 0.584 [P = .003]; cTnI, r = 0.605 [P = .002]). CONCLUSION: Measuring the plasma concentration of sICAM-1 before the concentrations of cardiac markers increase in patients with MI may provide clinicians with faster and reliable data for deciding on and administering the most appropriate procedures and/or therapies.

Comparative effects of tolazoline and nitroprusside on human isolated radial artery.

BACKGROUND: The radial artery is increasingly being used in coronary revascularization as an alternative conduit to a saphenous vein graft. Its perfect endothelial capacity provides a high patency rate comparable with the internal mammary artery (IMA). However, its spastic characteristics cause difficulties during its intraoperative preparation and may lead to early postoperative graft failure. Thus, treatment and/or prevention of radial artery spasm with an effective vasodilator agent is essential for its longevity. Endogenous vasoconstrictors, including noradrenaline, endothelin-1, and thromboxane A2, are likely to play a role in the pathogenesis of graft spasm. In the present study, we evaluated the vasorelaxant effect of tolazoline, a nonselective alpha-adrenoceptor blocker, against the contractions induced by various spasmogenic agents in an isolated human radial artery. METHODS: Tolazoline (10(-9)-10(-4) M) or sodium nitroprusside (SNP, 10(-9)-10(-4) M) were cumulatively applied on radial artery rings precontracted submaximally with noradrenaline, endothelin-1, thromboxane analogue, U46619, or potassium chloride. In addition, some rings were pretreated with tolazoline (4 x 10(-6) M) for 30 minutes and the contractile response curve to noradrenaline was assessed in its presence. RESULTS: Tolazoline effectively reversed noradrenaline-induced contractions in the radial artery, whereas it failed to produce remarkable relaxations on rings contracted with other spasmogenic agents, while SNP overcame the contractions induced by all spasmogens to a similar extent. In addition, brief pretreatment of radial artery rings with tolazoline significantly inhibited the contractions to noradrenaline. CONCLUSIONS: Tolazoline is not as broadly effective as SNP against all spasmogens investigated; however, it may be effective in counteracting alpha-adrenoceptor-mediated vasospasm in human radial arteries.