Role of coronary artery lumen enlargement in improving coronary blood flow after balloon angioplasty and stenting: a combined intravascular ultrasound Doppler flow and imaging study.
J Am Coll Cardiol
; 29(7): 1520-7, 1997 Jun.
Article
em En
| MEDLINE
| ID: mdl-9180114
ABSTRACT
OBJECTIVES:
This study sought to examine the mechanism of increasing coronary flow reserve after balloon angioplasty and stenting.BACKGROUND:
Coronary vasodilatory reserve (CVR) does not improve after percutaneous transluminal coronary angioplasty in > or = 50% of patients, postulated to be due to impaired microvascular circulation or inadequate lumen expansion despite adequate angiographic results.METHODS:
To demonstrate the role of coronary lumen expansion, serial coronary flow velocity (0.014-in. Doppler guide wire) was measured in 42 patients before and after balloon angioplasty and again after stent placement. A subset (n = 17) also underwent intravascular ultrasound (IVUS) imaging of the target sites after angioplasty and stenting. CVR (velocity) was computed as the ratio of adenosine-induced maximal hyperemic to basal average peak velocity.RESULTS:
The percent diameter stenosis decreased from (mean +/- SD) 84 +/- 13% to 37 +/- 18% after angioplasty and to 8 +/- 8% after stenting (both p < 0.05). CVR was minimally changed from 1.70 +/- 0.79 at baseline to 1.89 +/- 0.56 (p = NS) after angioplasty but increased to 2.49 +/- 0.68 after stent placement (p < 0.01 vs. before and after angioplasty). IVUS lumen cross-sectional area was significantly larger after stenting than after angioplasty (8.39 +/- 2.09 vs. 5.10 +/- 2.03 mm2, p < 0.05). Anatomic variables were related to increasing coronary flow velocity reserve (CVR vs. IVUS lumen area r = 0.47, p < 0.005; CVR vs. quantitative coronary angiographic percent area stenosis r = 0.58, p < 0.0001).CONCLUSIONS:
In most cases, increases in CVR were associated with increases in coronary lumen cross-sectional area. These data suggest that impaired CVR after angioplasty is often related to the degree of residual narrowing, which at times may not be appreciated by angiography. A physiologically complemented approach to balloon angioplasty may improve procedural outcome.
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Base de dados:
MEDLINE
Assunto principal:
Vasodilatação
/
Angioplastia Coronária com Balão
/
Stents
/
Ultrassonografia de Intervenção
/
Doença das Coronárias
/
Vasos Coronários
Limite:
Humans
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article