Bernard De Bruyne1,2,3, Ferry Hersbach1,2,3, Nico H.J. Pijls1,2,3, Jozef Bartúnek1,2,3, Jan-Willem Bech1,2,3, Guy R. Heyndrickx1,2,3, K. Lance Gould1,2,3, William Wijns1,2,3
1From the Cardiovascular Center Aalst (B.D.B., J.B., G.R.H., W.W.), Aalst, Belgium; the Catharina Hospital (F.H., J.W.B., N.H.J.P.), Eindhoven, the Netherlands; and the University of Texas Medical School (K.L.G.), Houston.
2PhD, Cardiovascular Center, Aalst, Moorselbaan 164, B-9300 Aalst, Belgium.
3University of Minnesota Medical School, Minneapolis
Tóm tắt
Background
Coronary arteries without focal stenosis at angiography are generally considered non–flow-limiting. However, atherosclerosis is a diffuse process that often remains invisible at angiography. Accordingly, we hypothesized that in patients with coronary artery disease, nonstenotic coronary arteries induce a decrease in pressure along their length due to diffuse coronary atherosclerosis.
Methods and Results
Coronary pressure and fractional flow reserve (FFR), as indices of coronary conductance, were obtained from 37 arteries in 10 individuals without atherosclerosis (group I) and from 106 nonstenotic arteries in 62 patients with arteriographic stenoses in another coronary artery (group II). In group I, the pressure gradient between aorta and distal coronary artery was minimal at rest (1±1 mm Hg) and during maximal hyperemia (3±3 mm Hg). Corresponding values were significantly larger in group II (5±4 mm Hg and 10±8 mm Hg, respectively; both
P
<0.001). The FFR was near unity (0.97±0.02; range, 0.92 to 1) in group I, indicating no resistance to flow in truly normal coronary arteries, but it was significantly lower (0.89±0.08; range, 0.69 to 1) in group II, indicating a higher resistance to flow. In 57% of arteries in group II, FFR was lower than the lowest value in group I. In 8% of arteries in group II, FFR was <0.75, the threshold for inducible ischemia.
Conclusion
Diffuse coronary atherosclerosis without focal stenosis at angiography causes a graded, continuous pressure fall along arterial length. This resistance to flow contributes to myocardial ischemia and has consequences for decision-making during percutaneous coronary interventions.
