Relationship Between Plasma Endothelin-1 Levels and Corrected TIMI Frame Count in Patients with Slow Coronary Artery Flow

PURPOSE
The aim of this study is to compaı·e the enclothelin levels between patients with slow coronary flow and normal healthy subjects, anel to investigate the relationship between endothelin-1 levels (ET -1 ) and correctecl TIMI frame co u nt (cTFC) between the two groups.
METHOD
The resting ET- ı levels w ere compareel be tween two groups (in 31 pa tients with s low coronary flow (groupA) and 15 heaıthy subjects (group B). At the same time the relationship between ET -1 and cTFC w as al so investigated.
RESULTS
Resting ET-I levels were found significantly high in patients with slow coronary flow when compareel with healthy subj ects (4,35±1.3 pg/ml vs 2.52±0.5 pg/ml, p<0.01). When the coronary vessels were compareel with each other according to the TIMI frame co u nt and ET- ı levels, if the dominant slow coronary flow was especially LAD arte ry (cTFC highest), ET-1 levels were found higher in these patients than in the ones with dominant Cx (p<0.02) or right corona ry artery (p<0.03). (LAD; 5.826±0,75 pg/ml , Cx; 4, 12±1.17 pg/ml, RCA; 3.89±1.49 pg/ml). But if slow coronary flow was dominant in Cx or RCA artery, not signif icant relationship between cTFC and ET-I levels was detected. When patients were classified according to the number of the diseased vessels, ET-1 levels were found highest in patients with 3-vessel d isease (3- vessel; 5,78±1,2 pg/ml, 2-vessel; 4.23±1.16 pg/ml, single vessel; 3.41±0,7 pg/ml. pCONCLUSION
Resting ET- l levels are high in patients with slow coronary flow as compareel with healthy subjects and show a s ignif icant correlation with cTFC. The increase in ET-1 levels may be responsible for the development of the chest pain in patients with slow coronary flow. Additionaly much more elinical studies are necessary to eletermine the exact role of ET -1 in the development of microvascular clysfunction.