RESTORATION OF CORONARY BLOOD-FLOW IN SEVERELY NARROWED AND CHRONICALLY OCCLUDED CORONARY-ARTERIES BEFORE AND AFTER ANGIOPLASTY - IMPLICATIONS REGARDING RESTENOSIS

The restenosis rate after recanalization of chronic totally occluded c oronary arteries is high. This may be due to a competitive flow or a l ow coronary flow velocity. This study was designed to assess differenc es in coronary blood flow velocity between severely narrowed and occlu ded arteries before and after successful percutaneous transluminal cor onary angioplasty. Thirty-five patient were studied including 12 with an occluded vessel (group 1) and 23 with a stenosis (group 2). Rest an d peak hyperemic (papaverine) coronary blood flow velocities were meas ured. Before successful percutaneous transluminal coronary angioplasty , velocity was lower in occlusions than in stenoses (3.8 +/- 2.1 vs 7. 9 +/- 4.8 cm/sec; p < 0.02), whereas resistance was higher (31.7 +/- 2 0.8 vs 13.7 +/- 7.0 mm hg/cm/sec, respectively; p = 0.0009). There was no significant difference in vasodilator reserve between the two grou ps. After successful percutaneous transluminal coronary angioplasty, t he velocity increased in both groups and the resistance index decrease d. Velocity and resistance were similar in the two groups. The vasodil ator reserve did not change after the procedure. It was concluded that the coronary flow velocity achieved after successful recanalization o f chronic totally occluded arteries is similar to that observed after dilatation of stenoses. These results do not support the hypothesis th at the high rate of restenosis in recanalized chronically occluded ves sels is due to differences in post-percutaneous transluminal coronary angioplasty blood flow velocity.