Effect of Diabetes Mellitus on Coronary Collateral Vessels

Although the pressure gradient between the normal and stenotic vascular regions is known to be most important factor for collateral vessel development, factors which are responsible for vari ations among patients with ischemic heart disease are not well known. Likewise, it is stili not clear whether diabetes mellitus (DM) has any effect on coronary collateral development. Coronary angiography, the most commonly used technique for studying collateral ci rculation, may not be accu rate in assessing col lateral c irculation because most collaterals are situated intramurally or too smail to visualize angiographically. Intracoronary pressuı·e ınea sureınent is a new technique to provide accurate and quantitative in formation about the collateral circulation. We therefore sought the effects of DM on coronary collateral vessels in patients with CAD by using intracoronary pressure ıneasureınent technique.
METHODS
Study population consisted of 40 patients (20 diabetic) with chronic ischeıni c heart disease referred to angiography laboratory due to their ischemic syınptoıns verifed prev iously with at least one non- invasive test. All of the patients had singlevessel disease with more than 70% narrowing and underwent PTCA and/or s tent iınplantation procedure for this vesseİ. After angiography, fibereptic pressure ınonitoring guide-wire (Pressure wireRadi) was advanced to the stenosis to be dilated. The same wire was used as guide wire for angioplasty catheter. During coınplete occlusion with balloon inflation, distal pressure was recorded as coronary wedge pressure (CWP). As a more va luable p ara ın ete r , collateral flow index (CFI) was determined by the ratio of siınultaneously ıneasured CWP (mmHg) to aortic pressure (Pa, mmHg, obtained from the guiding catheter) (CFI: CWP/Pa).
RESULTS
Pressure measurements were performed on 20 diabetic and 20 non-diabctic patients. The mean value of CWP was I 8. 1 ± 8.6 mmHg in the diabetic group and 26.8 ± 9.6 mmHg in the non-diabctic group (p<0.05). The ınean value of CFI was also significantly higher in the non-diabctic group (0.1 7 ± 0.08 in diabetic group and 0.25 + 0.09 in nondiabctic group, p<0.05) In conclusion, it was deınons trated that coronary collateral vessel development is impaired in diabetic patients compared with nondiabetic patients.