[Significance of the exercise test in the assessment of graft patency after myocardial revascularization with arteries only].
Although treadmill exercise testing (TET) has been used to identify ischaemia and determine clinical prognosis after myocardial revascularization, considerable controversy remains on its role in the detection of obstructive lesions of the arterial grafts.


OBJECTIVE
To assess the value of TET in determining the patency of arterial conduits after coronary bypass surgery with complete revascularization.


METHODS
Twenty five patients - 21 men and 4 women; age 53.7 +/- 8.7 years - submitted to complete myocardial revascularization exclusively with arterial conduits (CABG-A), undergoing coronary angiography and a symptomlimited TET (Bruce protocol) within 9 months after CABG-A. Angiograms were visually classified in 2 groups (Group I - conduits without lesions, n = 14; Group II > 50% stenosis or occlusion of > or = 1 conduit, n = 11). Clinical characteristics and the following parameters of the TET were compared: total exercise time (ETime); metabolic equivalents (METS); % of predicted maximal heart rate (% MHR); exercise-induced ST depression (decreases ST); and occurrence of angina. The arterial conduits used were: left internal mammary artery -24-; right internal mammary artery -11-; gastroepiploic artery -14-.


RESULTS
There were no differences in age, gender, left ventricular systolic function, severity of coronary artery disease, and number of conduits per patient. Group I attained superior values for the following parameters: ETime (p < 0.01) and METS (p < 0.01). Among Group II there were more patients with angina (p = 0.03). Fourteen patients exceeded 8 METS (11 from Group I and 3 from Group II - p = 0.002-). There was no statistical difference among the number of patients with ST depression during exercise.


CONCLUSIONS
After CABG-A the exercise tolerance seems to be related with the patency of the conduits and may play an important role in the detection of graft abnormalies. On the contrary, exercise-induced ST depression had low specificity in detecting obstructive lesions of the conduits.
Oliveira
M
M
Internato Complementar de Cardiologia, Hospital de Santa Marta, Lisboa.
Galrinho
A
A
Rosário
L
L
Cacela
D
D
Ferreira
R
R
Ferreira
M
M
Roquette
J
J
Quininha
J
J
Bento
R
R
Antunes
A M
AM
D001026:Coronary Artery Bypass / Q000379:methods; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014654:Vascular Patency
Importância da prova de esforço na avaliação da permeabilidade dos enxertos após revascularização miocárdica com utilização exclusiva de artérias.