Chronic infarct-related artery occlusion is associated with a reduction in capillary density. Effects on infarct healing

Abstract

Aim: To assess the relationship between infarct-related artery (IRA) stenosis and capillary density and to assess its effect on scar formation in the human heart.

Materials and methods: Morphometric evaluation was performed in 51 human hearts, as follows. Group I non-cardiac death (control), Group II post-Q-wave myocardial infarction (QMI) death and Group III patients who survived QMI and who underwent aneurysmectomy. Using morphometric parameters, the relationship between left ventricle (LV) mass, infarct size, IRA stenosis, cellular hypertrophy and changes in microcirculation were analyzed within the infarcted area and free LV wall.

Results: A significant reduction in capillary density within the infarcted area was noted in group II when compared to the control group (1525.6+/-378.5/mm(2) vs. 2968.7+/-457.3/mm(2); p<0.001). Reduction in capillary density was inversely related to infarct size (r=-0.616; p=0.006) and degree of IRA stenosis (r(S)=-0.512; p=0.03). The most significant reduction in capillary density was observed in patients with total IRA occlusion (1204.6+/-156.9/mm(2) vs. 1676.6+/-245.8/mm(2); p<0.001). Similarly, a reduction in capillary density of over 60% (1030.7+/-241.8/mm(2)) was observed within aneurysms resected surgically.

Conclusions: The study demonstrated precise quantification of the capillary network in patients following QMI. The most significant reduction in capillary density was observed in patients with chronic total IRA occlusion.