Characterization of contraction and perfusion in the lateral border zone between normal and ischemic myocardium following coronary occlusion by myocardial contrast echocardiography

Participation of mast cells in angiogenesis in the border zone of myocardial infarction in rats

BACKGROUND

We hypothesized that mast cells may participate in coronary angiogenesis in acute myocardial infarction, contributing to myocardial salvage.

METHODS

The left coronary artery was occluded in control (n = 30) and Ws rats (n = 30), which genetically lacked c-kit, resulting in a mast cell deficiency. Four weeks later, the infarct area, i.e., infarct core and surrounding infarct areas, and the non-infarct area were assessed histopathologically. The mast cell and small vessel densities were assessed using toluidine blue and alkaline phosphatase staining. Myocardial perfusion was assessed by myocardial contrast echocardiography (MCE).

RESULTS

In Ws rats, the percentage infarct core area increased (p < 0.05) compared with the controls, whereas the percentage surrounding infarct area decreased (p < 0.01). Mast cell density increased most in the surrounding infarct area (p < 0.01) in control rats, whereas mast cells were absent in Ws rats. Compared with the controls, coronary microvessel density decreased in the surrounding infarct area in Ws rats (p < 0.01). MCE showed that the percentage infarct core area, i.e., perfusion defect, increased (p < 0.05) and the percentage surrounding infarct area, i.e., reduced perfusion area, decreased (p < 0.01) in Ws rats.

CONCLUSION

Mast cells may participate in promoting coronary angiogenesis in the infarct area surrounding the infarct core, contributing to attenuation of left ventricular dysfunction.

Chronic kidney disease, mortality, and treatment strategies among patients with clinically significant coronary artery disease

Cardiovascular disease is an important cause of mortality among patients with chronic kidney disease (CKD). This study describes associations between CKD, cardiac revascularization strategies, and mortality among patients with CKD and cardiovascular disease. All patients undergoing cardiac catheterization at Duke University Medical Center (1995 to 2000) with documented stenosis > or =75% of at least one coronary artery and available creatinine data were included. CKD was staged using creatinine clearance (CrCl) derived from the Cockcroft-Gault formula (normal, > or = 90 ml/min; mild, 60 to 89 ml/min; moderate, 30 to 59 ml/min; severe, 15 to 29 ml/min). Cox proportional-hazard regression estimated the relationship between clinical variables, including CrCl and percutaneous coronary artery intervention (PCI), coronary artery bypass grafting (CABG), medical management, and patient survival. There were 4584 patients included, and 24% had CrCl <60 ml/min. Each 10-ml/min decrement in CrCl was associated with an increase in mortality (hazard ratio, 1.14; P < 0.0001). CABG was associated with a survival benefit among patients with both normal renal function and patients with CKD compared with medical management. In patients with normal renal function, CABG was not associated with survival benefit over PCI. However, in patients with CKD, CABG was associated with improved survival. PCI was associated with a survival benefit compared with medical management among patients with normal, mildly, and moderately impaired renal function. Among patients with severe CKD, PCI was not associated with improved survival. CABG is associated with greater mortality reduction than PCI in severe CKD.