The relation between chronic obstructive pulmonary disease and coronary collateral vessels.

Coronary collateral vessels can provide a perfusion reserve in case of increased myocardial oxygen demand. Development of coronary collateral vessels (CCV) is triggered by the pressure gradient between the coronary bed of arteries caused by an obstruction and myocardial ischemia. Myocardial hypoxia can facilitate development of CCVs. There is a chronic hypoxemia in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the effect of COPD on CCVs. The study included 98 patients with COPD who underwent coronary angiography. Those patients in whom coronary angiography is normal or severity of coronary artery stenosis in thought not to be sufficient for the development of CCVs (<80%) were excluded from the study. A total of 98 patients (mean age, 62 +/-9 years) met the criteria for the COPD group. For case-control matching, 98 consecutive without COPD patients (mean age 62 +/-10) who had one or more diseased vessels with 80% or greater stenosis were included in the control group. The CCVs were graded according to the Rentrop scoring system, and the collateral score was calculated by summing the Rentrop numbers of every patient. The mean number of diseased vessels in patients with COPD and without COPD were 1.61 +/-0.69 and 1.77 +/-0.89 (p=0.155), respectively. The mean collateral score was 2.15 +/-2.03 in the COPD group and 1.32 +/-1.54 in the control group. After confounding variables were controlled for, the collateral score in patients with COPD group was significantly different from that in patients without COPD group (p=0.002). These findings suggest that CCV development is better in patients with COPD than in those patients without COPD. Thus, COPD may be an important factor affecting CCV development, which may be related to the presence of chronic hypoxemia in patients with COPD.