Serial transthoracic coronary Doppler shows complete reversibility of microvascular obstruction pattern at one month after reperfused acute myocardial infarction.

Abstract

“No reflow” phenomenon is a common complication with significant prognostic repercussions after reperfused acute myocardial infarction. Previous studies have shown the feasibility and prognostic significance of coronary microcirculation assessment by transthoracic Doppler of left anterior descending artery (LAD). The aim of the study was to evaluate the time course of the coronary microcirculation status after acute anterior myocardial infarction reperfused by primary angioplasty with stent on LAD. Material and methods: Twenty-three patients underwent transthoracic echocardiography at 3 days (M0) and one month (M1) after reperfusion, with LAD flow analysis (peak systolic and diastolic velocities, diastolic deceleration time and systolic flow reversal). The patients were divided into two groups, of good reperfusion and “no reflow”, by a 600 ms cut-off of the M0 diastolic deceleration time, previously shown to best discriminate between the two microvascular reperfusion states. Results: Of all patients, 21 survived to M1 and were included in analysis. Microvascular obstruction, as defined, was present in 50% of patients at M0 and it was associated with significantly worse ejection fraction both at M0 and M1 (p=0.01 and 0.04, respectively). Killip class at admission was the only independent predictor of “no reflow”. DDT increased from 661.9±339.3 at M0 to 948.2±201.8 at M1 (p=0.0003). In patients with initial “no reflow”, DDT increased to normal values at M1 (876.2±167.7 vs. 346.3±133.9 at M0, p<0.0001). In these patients, the PDV/PSV ratio decreased at one month (1.91±0.37 vs. 2.70±1.22, p=0.06), by decrease of PDV (0.29±0.06 vs. 0.40±0.19, p=0.03). Conclusions: The parameters of coronary microcirculatory impedance improve significantly at one month after infarction, suggesting delayed full reversibility of the microvascular obstruction.

Predictors of diastolic deceleration time of coronary flow velocity of infarct related and reference coronary artery assessed by transthoracic Doppler echocardiography in the chronic phase of successfully reperfused anterior myocardial infarction: relation to infarct size

“…After an acute ischemic injury in the later phase of the MI microvascular function recovers, which is manifested by prolongation of the diastolic deceleration time in the IRA ( 6 , 11 , 12 ). This recovery of microcirculation is a consequence of the gradual recanalization of occluded small blood vessels and neoangiogenesis in the infarcted zone with an increase in the capacitance of intramyocardial circulation ( 32 ).…”

“…It has been demonstrated that after acute ischemic injury, microvascular function gradually improves within one month with a subsequent increase of DDT of IRA ( 11 , 12 ). Importantly this improvement is translated into the reduction of infarct size ( 13 ).…”

The Role of Microvascular Obstruction and Intra-Myocardial Hemorrhage in Reperfusion Cardiac Injury. Analysis of Clinical Data

“…[ 65 ], MVO was found in 56% of patients with STEMI and PCI by MRI. MVO was diagnosed by echocardiography in 50% of patients with STEMI and PCI [ 69 ]. It was reported that no-reflow (TIMI = 0–2) was documented in 25% of patients with STEMI and PCI [ 7 ].…”

“…Currently, the assessment of MVO often uses both angiography and MRI (Table 1 , Ref. [ 5 , 7 , 9 , 10 , 11 , 12 , 13 , 14 , 16 , 17 , 18 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]). However, in recent years, investigators increasingly favor MRI as a more accurate method of assessing MVO.…”

A historical literature review of coronary microvascular obstruction and intra-myocardial hemorrhage as functional/structural phenomena

“…The persistent full no-reflow phenomenon (the Thrombolysis in Myocardial Infarction [TIMI] flow grade 0) can be angiographically found in approximately 5% of patients with AMI and PCI, but MVO may be more common [ 7 ] . MVO has been diagnosed by the contrast-enhanced magnetic resonance imaging (MRI) in 25% of patients with STEMI [ 9 ] , diagnosed angiographically in 29% of patients with both STEMI and PCI [ 10 ] , but detected by MRI in 56% of patients with both STEMI and PCI [ 11 ] and diagnosed with transthoracic echocardiography in 50% of patients with both STEMI and PCI [ 12 ] . MVO also can be detected by the angiographic TIMI flow grade in 25% of patients with STEMI and PCI in one study [ 13 ] but in 46% of patients with STEMI and PCI by the same method in another study [ 14 ] .…”