Coronary flow velocity pattern assessed by transthoracic Doppler echocardiography predicts adverse clinical events and myocardial recovery after successful primary angioplasty

Clinical significance of early systolic reverse flow in left anterior descending coronary artery on transthoracic echocardiography in patients with acute myocardial infarction

BACKGROUND

Predicting the cardiac function in chronic phase of acute myocardial infarction (AMI) patients is important. Previous studies showed that the presence of early systolic reverse flow (ESRF) in coronary flow measured with a Doppler guide wire is a predictor of worsening chronic phase function in patients with anterior AMI. We routinely examined the coronary flow velocity (CFV) of the distal left anterior descending artery (LAD) using transthoracic echocardiography (TTE) in AMI patients. The aim of this study is to investigate whether the ESRF in TTE is associated with the chronic cardiac function, recovery of cardiac function, and the incidence of major adverse cardiac events (MACE) in patients with anterior AMI.

METHODS

We enrolled 84 patients with their first anterior AMI. Using TTE, we recorded the CFV of distal LAD within 5 days after primary percutaneous coronary intervention. Patients were divided into two groups, ESRF + group (ESRF was detected in TTE: 21 cases) and ESRF- group (ESRF was not detected in TTE: 63 cases). We compared chronic cardiac function in TTE, changes in cardiac function in acute and chronic phase (ΔLVEF, ΔLVDd), and the incidence of MACE.

RESULTS

The incidence of MACE in ESRF-group was lower than that in ESRF + group (3.3% vs 19.1% P = .02). LVEF in chronic phase in ESRF- group was higher than that in ESRF + group (54.1 ± 5.6% vs 40.4 ± 6.2% P < .001). ΔLVDd was smaller in ESRF-group than ESRF + group (-0.62 ± 4.0 mm vs +5.06 ± 3.4 mm P = .003).

CONCLUSION

Early systolic reverse flow in TTE is a predictor of chronic cardiac function and incidence of MACE in patients with anterior AMI.

[Usefulness of diastolic deceleration time assessed by transthoracic Doppler measurement in the detection of sustained microvascular obstruction in STEMI patients treated by primary PTCA]

AIMS

To assess the value of coronary flow measurement by transthoracic Doppler technique in the detection of "no-reflow" phenomenon.

METHODS

Fourteen patients with first anterior wall infarction treated by successful (TIMI3) primary percutaneous angioplasty and left descending coronary artery stenting were investigated. Myocardial perfusion following PCI was assessed by (i) ST-segment resolution, (ii) MRI-detected microvascular obstruction (early hypoenhancement), (iii) coronary flow pattern measurement by transthoracic Doppler technique.

RESULTS

Sustained impairment of myocardial perfusion following PCI was observed in a large proportion of the cohort (36% by MRI, 43% by ST regression analysis). Patients with a diastolic deceleration time inferior to 482 ms had higher troponin and CK peak value, higher wall motion index score, lower ST resolution and lower LVEF assessed by MRI. The concordance of the three methods was 80%.

CONCLUSION

The measurement of diastolic deceleration time by transthoracic Doppler technique is a reliable technique to identify microvascular obstruction following PCI in acute anterior STEMI. A DDT inferior to 482 ms is associated with sustained "no-reflow" phenomenon.

Coronary no-reflow phenomenon: from the experimental laboratory to the cardiac catheterization laboratory

Coronary no-reflow occurs commonly during acute percutaneous coronary intervention, particularly in patients with acute myocardial infarction and those with degenerated vein grafts. It is associated with a guarded prognosis, and thus needs to be recognized and treated promptly. The pathophysiology originates during the ischemic phase and is characterized by localized and diffuse capillary swelling and arteriolar endothelial dysfunction. In addition, leukocytes become activated and are attracted to the lumen of the capillaries, exhibit diapedesis and may contribute to cellular and intracellular edema and clogging of vessels. At the moment of perfusion, the sudden rush of leukocytes and distal atheroemboli further contributes to impaired tissue perfusion. Shortening the door-to-balloon time, use of glycoprotein IIb/IIIa platelet receptor inhibitors and distal protection devices are predicted to limit the development of no-reflow during percutaneous interventions. Distal intracoronary injection of verapamil, nicardipine, adenosine, and nitroprusside may improve coronary flow in the majority of patients. Hemodynamic support of the patient may be needed in some cases until coronary flow improves.