Relationship between pressure-derived collateral blood flow and diabetes mellitus in patients with stable angina pectoris: a study based on coronary pressure measurement

Abstract

Although the pressure gradient between the normal and stenotic vascular regions is known to be the most important factor for collateral vessel development, factors which are responsible for variations among patients with ischemic heart disease are not well known. Likewise, it is still not clear whether diabetes mellitus (DM) has any effect on coronary collateral development. Coronary angiography, the most commonly used technique for studying collateral circulation, may not be accurate in assessing collateral circulation because most collaterals are situated intramurally or are too small to visualize angiographically. Intracoronary pressure measurement is a new technique to provide accurate and quantitative information about the collateral circulation. Therefore, we sought the effects of DM on coronary collateral vessels in patients with coronary artery disease by using intracoronary pressure measurement technique.

Methods: Study material consisted of 40 patients (20 diabetic) with chronic ischemic heart disease referred to angiography laboratory due to their ischemic symptoms verified previously with at least one non-invasive test. All of the patients had single vessel disease with more than 70% narrowing and had undergone PTCA and/or stent implantation procedure for this vessel. Quantitative coronary angiographic analysis (QCA) and all of the coronary pressure measurements were performed both pre- and post-revascularization procedure. After angiography, a fiber-optic pressure monitoring guidewire (Pressure wire, RADI Medical Systems, Inc., Reading, Massachusetts) was advanced to the stenosis to be dilated. The same wire was used as a guidewire for the angioplasty catheter. During complete occlusion with balloon inflation, distal pressure was recorded as coronary wedge pressure (CWP). As a more valuable parameter, collateral flow index (CFI) was determined by the ratio of simultaneously measured CWP (mmHg) to mean aortic pressure (Pa, mmHg, obtained from the guiding catheter) (CFI: CWP/Pa).

Results: Pressure measurements were performed on 20 diabetic and 20 non-diabetic patients. The mean value of CWP was 18.1 8.6 mmHg in the diabetic group and 26.8 +/- 9.6 mmHg in the non-diabetic group; this difference was statistically significant (p < 0.01). Also, the mean value of CFI was significantly higher in the non-diabetic group (0.17 +/- 0.08 in the diabetic group and 0.25 0.09 in the non-diabetic group; p < 0.01).

Conclusion: This study demonstrated that the coronary collateral vessel development is impaired in diabetic patients compared with non-diabetic patients.