Jiro Ikata

Leukocyte counts and concentrations of soluble adhesion molecules as predictors of coronary atherosclerosis.

BackgroundAuthors of recent studies have reported that there is a relationship between level of adhesion molecules and atherosclerosis. In an animal study it was demonstrated that there is an interaction between adhesion molecules and leukocytes in atherosclerotic tissue. ObjectiveTo study the relationships between coronary‐artery atherosclerosis and both differential blood‐leukocyte count and concentrations of soluble adhesion molecules in patients with and without coronary artery disease (CAD). MethodsOur subjects were 168 patients who underwent diagnostic coronary angiography. Forty‐eight patients had normal coronary angiograms (control group), and 120 patients had significant coronary‐artery stenoses (diameter stenosis > 70%) in at least one major coronary‐artery branch (CAD group). Total and differential blood‐leukocyte counts, and concentrations of soluble intercellular adhesion molecule‐1 (sICAM‐1) and vascular cell adhesion molecule‐1 (sVCAM‐1) were assayed prior to angiography. ResultsMonocyte counts for patients in the CAD group were significantly greater than those for patients in the control group (366 ± 99 versus 258 ± 44/μl, P  < 0.0001), as were the sICAM‐1 concentrations (272 ± 52 versus 203 ± 24 ng/ml, P  < 0.0001). The mean concentrations of sVCAM‐1 in members of the two groups were the same (671 ± 138 versus 668 ± 97 ng/ml, P  = 0.4). There was a higher incidence of significant coronary‐artery stenosis among patients with both a high monocyte count and a high concentration of sICAM‐1 (≥ mean+SD) than there was among patients with a low monocyte count and a low concentration of sICAM‐1 (≥ mean−SD; 100 versus 25%, P  < 0.0001). ConclusionsHigher levels both of monocyte counts and of serum concentrations of ICAM‐1 may serve as markers for coronary atherosclerosis.

Coronary flow velocity patterns immediately after reperfusion reflect the pathologic characteristics of reperfused myocardium in canine models of acute myocardial infarction

BackgroundIt is difficult to evaluate the extent of myocardial injury after successful reperfusion following acute myocardial infarction (AMI). We investigated the relationship between the coronary flow velocity pattern immediately after reperfusion and pathologic characteristics after myocardial reperfusion injury in dogs. MethodsWe measured distal coronary flow velocity variables in the left circumflex coronary artery in a canine model of AMI (n = 12) 10 min after the release of a clamp (3–10 h clamp procedure) using a 0.35 mm Doppler guide-wire. Dogs were divided into two groups according to presence or absence of early systolic retrograde coronary flow. Hearts were excised 2 h after reperfusion and examined histopathologically. ResultsThe clamping time tended to be longer in dogs with early systolic retrograde coronary flow. Neutrophil infiltration was observed in the myocardium of dogs without systolic retrograde flow (n = 9); hemorrhage was rarely detectable and the myocardium maintained a bundle form. However, the bundle form of the myocardium became rough, and the severity of the incidence of hemorrhage tended to increase as the ratio of the diastolic coronary flow velocity to systolic velocity (DSVR) decreased. Vacuolar degeneration of the myocardium was also observed in hearts with a relatively low DSVR. In the group with systolic retrograde flow (n = 3), hearts were characterized by coagulation necrosis, marked vacuolar degeneration of the myocardium and diffusely distributed red cells in the intermyocytes. Systolic antegrade flow velocity was much reduced in this group, resulting in a markedly increased DSVR. These findings appeared to be related to severe myocardial damage. ConclusionsCoronary flow velocity patterns immediately after successful reperfusion appear to reflect the pathologic characteristics of the reperfused myocardium in dogs with AMI. Coronary Artery Dis 9:21–27

Coronary Flow Velocity Immediately After Reperfusion Reflects Myocardial Microcirculation in Canine Models of Acute Myocardial Infarction

Recent reports indicate that the coronary microcirculation is sometimes injured, despite successful reperfusion in acute myocardial infarction (AMI). However, it is difficult to evaluate the coronary microcirculation immediately after reperfusion by using only angiography. The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity and myocardial microcirculatory injury immedi ately after reperfusion in AMI. The authors recorded the left circumflex coronary flow velocity by using the Doppler guide wire method 10 minutes after reperfusion in a canine model of AMI. In addition, myocardial contrast echocardiography was performed with the injection of contrast medium into the left circumflex coronary artery before clamping of the coronary artery and 15 minutes after release of the clamp. From these images, the ratio of the normalized gray-level postreperfusion to preclamping in the contrast- enhanced area was determined. It was compared with coronary flow velocity variables. In the 10 dogs with a diastolic-to-systolic velocity ratio (DSVR) < 4.0, this velocity ratio 10 minutes after reperfusion correlated positively (r = 0.75, p < 0.01) with the normal ized gray-level ratio. However, the remaining three dogs with a DSVR ≥ 4.0 markedly deviated from this pattern. Coronary flow velocities in the three dogs were characterized by a greater decrease in systolic flow velocity and occurrence of early systolic retrograde flow. Myocardial contrast echocardiographic images in these three dogs demonstrated a lower normalized gray-level ratio. In conclusion, the coronary flow velocity pattern imme diately after reperfusion may reflect myocardial microcirculatory injury.

Characteristics of coronary flow velocity in constrictive pericarditis

A 50-yr-old man developed constrictive pericarditis following an episode of acute pericarditis. Cardiac catheterization revealed a typical early diastolic dip and plateau configuration in both the right and left ventricular pressure curves. The coronary flow velocity pattern determined using an intracoronary Doppler guidewire showed an abrupt decrease in peak velocity at early diastole and followed by plateau until late diastole, the so-called dip and plateau configuration. After a successful pericardiectomy, cardiac catheterization no longer showed the dip and plateau configuration, but the early diastolic dip in the coronary flow velocity persisted probably because of infiltration of the organic involvement into the myocardium.