Lack of myocardial perfusion immediately after successful thrombolysis. A predictor of poor recovery of left ventricular function in anterior myocardial infarction.

Abstract

BACKGROUND We investigated myocardial perfusion dynamics after thrombolysis and its clinical implications. METHODS AND RESULTS We studied 39 patients with acute anterior myocardial infarction (AMI). Myocardial contrast echocardiography (MCE) was performed before and immediately after successful reflow with intracoronary injection of sonicated Ioxaglate. The average segmental score by two-dimensional echocardiography (graded 0, normal, to 3, akinetic/dyskinetic) and global ejection fraction (left ventricular ejection fraction, LVEF%) by left ventriculography were measured at 1 day and at 4 weeks after reflow. Hypokinesis in the infarct region was assessed by the centerline method and expressed in terms of standard deviations (regional wall motion [RWM]: SD/chord) of normal. Immediately after reflow, 30 of 39 patients (group A) showed significant contrast enhancement within the risk area. The other nine patients (23%, group B), however, showed the residual contrast defect in the risk area (myocardial no reflow). There were no significant differences in the elapsed time, angiographic collateral grade, and degree of residual stenosis between group A and group B. Before reflow, both groups exhibited similar levels of global and regional left ventricular function. Improvement in global (LVEF, average segmental score) and regional left ventricular function was greater in group A than in group B (average segmental score, 0.44 +/- 0.41 versus 0.97 +/- 0.36, p less than 0.01; LVEF, 56.4 +/- 13.4 versus 42.7 +/- 8.9, p less than 0.05; RWM, -1.87 +/- 0.85 versus -3.18 +/- 0.52, p less than 0.005). CONCLUSIONS MCE demonstrates that angiographically successful reflow cannot be used as an indicator of successful myocardial reperfusion in AMI patients. The residual contrast defect in the risk area demonstrated immediately after reflow is a predictor of poor functional recovery of the postischemic myocardium.

Markers of myocardial reperfusion as predictors of left ventricular function recovery in acute myocardial infarction treated with primary angioplasty

“…Impaired myocardial reperfusion after AMI is associated with a greater infarct size, poorer LV function, higher rate of congestive heart failure, and higher mortality. 1 Angiographic MBG, cTFC, and ST-segment elevation index are parameters easily obtainable to evaluate myocardial reperfusion. [5][6][7][8] Myocardial blush is related to the enzymatic infarct size, the extent of ST-segment elevation resolution, LV function, and long-term mortality in patients with AMI after primary PCI, 7 as well as to the final infarct size and the degree of myocardial salvage assessed by scintigraphy.…”

“…Some reperfusion parameters can be obtained by myocardial contrast echocardiography, Doppler flow wire, myocardial scintigraphy, and magnetic resonance imaging; however, their application is difficult and time consuming. [1][2][3][4] On the other hand, the resolution of ST-segment elevation, 5,6 the angiographic myocardial blush grade (MBG), 6,7 and the corrected Thrombolysis In Myocardial Infarction (TIMI) frame count (cTFC) 8 are early and easily obtainable during the acute stage of AMI treated with primary coronary intervention (PCI) .…”

Persistent st‐segment elevation after primary stenting for acute myocardial infarction: Its relation to left ventricular recovery

“…Impaired tissue reperfusion after successful recanalization of an epicardial coronary artery has been documented both in animals 6 and in patients [7][8][9][10][11] with AMI. Thus, the degree of functional recovery is related to the extent of microvascular damage.…”

“…This socalled "low or no-reflow" phenomenon was first described by Kloner et al in an animal model. 6 Thereafter, this phenomenon has been evaluated by various methods, including myocardial contrast echocardiography (MCE), 7,8 scintigraphy, 9,10 and positron emission tomography (PET) 11 in patients with AMI. However, these techniques are costly and unavailable in routine clinical practice.…”

Remodelage précoce du ventricule gauche après un accident coronarien aigu

“…Il s'agit d'un phénomène dynamique prenant place au cours des premiers jours de l'infarctus. La consé-quence en est finalement une insuffisance ou une absence de reperfusion (no-reflow) au niveau tissulaire, en dépit d'une artère épicardique réouverte [33], qui prolongent et aggravent l'ischémie et la mort cellulaire du territoire concerné. Diffé-rentes techniques cliniques permettent de documenter ce phé-nomène: visualisation échographique ou par IRM (imagerie par résonance magnétique) d'un défaut de prise de contraste tissulaire après injection intracoronaire ou périphérique d'un soluté, mesure de la réserve coronaire par Doppler.…”