Quantification of recruitable coronary collateral blood flow in conscious humans and its potential to predict future ischemic events.

OBJECTIVES The present study was designed to evaluate the applicability of a pressure-flow equation for quantitative calculation of recruitable collateral blood flow at coronary artery occlusion in conscious patients and to investigate the value of that index to predict future ischemic events. BACKGROUND Recent experimental studies have indicated that recruitable collateral blood flow at coronary artery occlusion can be expressed as a fraction of normal maximal myocardial blood flow by simultaneous recordings of mean arterial, coronary wedge and central venous pressures, respectively. This index is called the pressure-derived fractional collateral flow and is independent of hemodynamic loading conditions. METHODS In 120 patients undergoing elective coronary angioplasty, mean arterial, coronary wedge and central venous pressures were measured at balloon inflations of 2 min. All patients had a recent exercise electrocardiogram (ECG) with positive findings showing clearly distinguishable, reversible ECG abnormalities, enabling recognition of ischemia at balloon inflation. Fractional collateral blood flow at angioplasty was calculated by coronary wedge pressure minus central venous pressure divided by mean arterial pressure minus central venous pressure and correlated to the presence or absence of ischemia at balloon inflation. Ischemic events were monitored during a follow-up period of 6 to 22 months. RESULTS In 90 of the 120 patients, ischemia was present at balloon inflation, and in 82 of these patients, fractional collateral blood flow was < or = 23%. By contrast, in 29 patients, no ischemia was present, and fractional collateral blood flow was > 24% in all 29. During the follow-up period, 16 patients had an ischemic event. Fifteen of these 16 patients were in the group with insufficient collateral flow (p < 0.05). CONCLUSIONS To our knowledge, this study presents the first method for quantitative assessment of recruitable collateral blood flow in humans in the catheterization laboratory. Sufficient and insufficient collateral circulation can be reliably distinguished by this method. Use of this method can also help to provide more insight into the extent and behavior of the collateral circulation for investigational purposes and may have potential clinical implications.

[1]  G W Hamilton,et al.  Physiologic basis for assessing critical coronary stenosis. Instantaneous flow response and regional distribution during coronary hyperemia as measures of coronary flow reserve. , 1974, The American journal of cardiology.

[2]  G. Uijen,et al.  Concept of Maximal Flow Ratio for Immediate Evaluation of Percutaneous Transluminal Coronary Angioplasty Result by Videodensitometry , 1991, Circulation.

[3]  M. Mohri,et al.  Duration of Ischemia Is Vital for Collateral Development: Repeated Brief Coronary Artery Occlusions in Conscious Dogs , 1989, Circulation research.

[4]  J. Longhurst,et al.  Function and Development of Coronary Collateral Vessels , 1992 .

[5]  K. Gould,et al.  Coronary flow reserve as a physiologic measure of stenosis severity. , 1990, Journal of the American College of Cardiology.

[6]  J. Hoffman.  Maximal coronary flow and the concept of coronary vascular reserve. , 1984, Circulation.

[7]  M. Fujita,et al.  Importance of angina for development of collateral circulation. , 1987, British heart journal.

[8]  A. J. Dunning,et al.  Spectral analysis of flow velocity in the contralateral artery during coronary angioplasty: a new method for assessing collateral flow. , 1993, Journal of the American College of Cardiology.

[9]  M. Kotler,et al.  Stimulation of coronary collateral growth: current developments in angiogenesis and future clinical applications. , 1992, American heart journal.

[10]  J. Schaper,et al.  Collateral Vessel Development in the Porcine and Canine Heart , 1992 .

[11]  M. Fujita,et al.  Recent insights into coronary collateral circulation. , 1992, Circulation.

[12]  F. Crea,et al.  Myocardial ischemia caused by distal coronary-artery constriction in stable angina pectoris. , 1990, The New England journal of medicine.

[13]  A. Kurita,et al.  Role of coronary collateral vessels during transient coronary occlusion during angioplasty assessed by hemodynamic, electrocardiographic and metabolic changes. , 1988, Journal of the American College of Cardiology.

[14]  A. Bol,et al.  Mechanisms of Chronic Regional Postischemic Dysfunction in Humans New Insights From the Study of Noninfarcted Collateral‐Dependent Myocardium , 1993, Circulation.

[15]  F. Feit,et al.  Determinants and protective potential of coronary arterial collaterals as assessed by an angioplasty model. , 1988, The American journal of cardiology.

[16]  A. J. Dunning,et al.  Severity of single-vessel coronary arterial stenosis and duration of angina as determinants of recruitable collateral vessels during balloon angioplasty occlusion. , 1991, The American journal of cardiology.

[17]  R. Bache,et al.  Effect of Aspirin on Coronary Collateral Blood Flow , 1993, Circulation.

[18]  W. Rutishauser,et al.  Potential protective effect of high coronary wedge pressure on left ventricular function after coronary occlusion. , 1988, Circulation.

[19]  M. Nakamura,et al.  Development of Collateral Function with Repetitive Coronary Occlusion in a Canine Model Reduces Myocardial Reactive Hyperemia in the Absence of Significant Coronary Stenosis , 1984, Circulation research.

[20]  D. Harrison,et al.  Neurohumoral Regulation of Collateral Perfusion , 1991, Circulation.

[21]  M. Kern,et al.  Coronary flow velocity dynamics in normal and diseased arteries. , 1993, The American journal of cardiology.

[22]  W. Schaper.  Coronary Collateral Development: Concepts and Hypotheses , 1992 .

[23]  W. Schaper,et al.  The collateral circulation of the heart. , 1988, Progress in cardiovascular diseases.

[24]  W. Paulus,et al.  Transstenotic coronary pressure gradient measurement in humans: in vitro and in vivo evaluation of a new pressure monitoring angioplasty guide wire. , 1993, Journal of the American College of Cardiology.

[25]  M. Kern,et al.  Quantitating coronary collateral flow velocity in patients during coronary angioplasty using a Doppler guidewire. , 1993, The American journal of cardiology.

[26]  W. Rutishauser,et al.  Coronary wedge pressure in relation to spontaneously visible and recruitable collaterals. , 1987, Circulation.

[27]  A Bol,et al.  Coronary flow reserve calculated from pressure measurements in humans. Validation with positron emission tomography. , 1994, Circulation.

[28]  O. Hess,et al.  Determination of coronary flow reserve by parametric imaging. , 1990, Circulation.

[29]  B. De Bruyne,et al.  Experimental Basis of Determining Maximum Coronary, Myocardial, and Collateral Blood Flow by Pressure Measurements for Assessing Functional Stenosis Severity Before and After Percutaneous Transluminal Coronary Angioplasty , 1993, Circulation.