Relation of phasic coronary flow velocity characteristics with TIMI perfusion grade and myocardial recovery after primary percutaneous transluminal coronary angioplasty and rescue stenting.

ABSTRACT

BACKGROUND: A residual stenosis and/or microvascular damage have been proposed as mechanisms of TIMI 2 flow for acute myocardial infarction. Coronary flow dynamics were assessed in patients with TIMI 2 flow to predict whether additional intervention would improve TIMI grade. METHODS AND RESULTS: In 35 patients who had a successfully recanalized anterior acute myocardial infarction using angioplasty or rescue stenting, coronary flow patterns were compared with corresponding TIMI grade and regional left ventricular wall motion (LVWM) 1 month after the intervention. After angioplasty, the time-averaged peak velocity (APV) was lower in patients with TIMI 2 flow (n=22) than in those with TIMI 3 flow (n=13; 7.9+/-3.9 versus 20.6+/-5.1 cm/s; P<0.001). Two different flow patterns were recorded in patients with TIMI 2 flow (versus TIMI 3, P<0.001); patients with type 1 TIMI 2 flow (n=15) had a reduced diastolic APV (8.3+/-4.8 versus 24.2+/-7.4 cm/s), prolonged diastolic deceleration time (1176+/-455 versus 728+/-205 ms), and a small diastolic/systolic APV ratio (1.3+/-0.6 versus 2.1+/-0.7); patients with type 2 TIMI 2 flow (n=7) had systolic flow reversal (systolic APV, -7.9+/-4.6 versus 11. 7+/-4.5 cm/s), a rapid diastolic deceleration time (221+/-84 versus 728+/-205 ms), and a negative diastolic/systolic APV ratio (-2.1+/-1. 4 versus 2.1+/-0.7). A significantly lower mean chord LVWM (-3.0+/-0. 2 versus -1.9+/-0.8; P<0.001) and a greater number of chords <-2SD (50+/-2 versus 28+/-18; P<0.001) were present in patients with type 2 versus type 1 TIMI 2 flow. Stenting increased TIMI 2 flow to TIMI 3 flow more in patients with type 1 than type 2 flow (67% versus 0%; P=0.003). Patients with TIMI 2 flow after stenting continued to demonstrate a type 2 pattern, and they had poor LVWM recovery. CONCLUSIONS: The differentiation between 2 types of TIMI 2 flow can predict the improvement of TIMI grade and LVWM recovery after additional stenting.