Premium
Arteriolar remodeling limits maximal perfusion after percutaneous revascularization of a chronic stenosis in pigs with hibernating myocardium
Author(s) -
Weil Brian Raymond,
Page Brian J,
Banas Michael D,
Suzuki Gen,
Canty John M
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1055.9
Subject(s) - hibernating myocardium , cardiology , medicine , perfusion , lumen (anatomy) , vasodilation , microcirculation , ischemia , restenosis , stenosis , coronary circulation , adenosine , endocardium , conventional pci , revascularization , blood flow , stent , myocardial infarction
Chronic myocardial ischemia results in remodeling of the coronary microcirculation in hibernating myocardium but the reversibility of these changes is unknown. Accordingly, we evaluated parameters of arteriolar structure and measured transmural myocardial perfusion during adenosine vasodilation before and up to one month after percutaneous coronary intervention (PCI) of a chronic LAD stenosis in swine (n=12). Regional function was depressed at rest (LAD wall thickening 38.6±4.0 vs. 92.2±7.5%, p<0.05). Immediately after PCI, subendocardial flow during adenosine vasodilation increased from 1.5±0.3 to 4.6±0.8 ml/min/g, but fell to 2.7±0.3 ml/min/g one month later without evidence of restenosis. Histological assessment of subendocardial resistance vessel remodeling is shown below:Group Subendocardial Arterioles Lumen Area (μm 2 ) Density (arterioles/mm 2 ) WT/Lumen Diameter (%)Hibernating (n=148) 721±67 * 10.7±1.8 * 37.3±1.5 *Revascularized (n=54) 659±88 * 5.8±0.4 40.3±2.2 *Sham (n=54) 1184±173 6.2±0.3 28.7±1.3Values are mean±SEM; n=total number of vessels analyzed; WT=wall thickness;* p<0.05 vs. Sham.These data indicate that there is subendocardial microvascular remodeling in hibernating myocardium with an increase in arteriolar density compensating for a reduction in arteriolar lumen area. After revascularization, arteriolar density returns to normal but lumen area remains reduced and decreases maximal perfusion. These chronic microvascular structural changes could precipitate subendocardial ischemia in the absence of coronary restenosis. Supported by NIH HL61610.