Quantitative segmental analysis of myocardial perfusion to differentiate stress cardiomyopathy from acute myocardial infarction: A myocardial contrast echocardiography study

Prognostic value of myocardial contrast echocardiography in acute anterior wall ST-segment elevation myocardial infarction with successful epicardial recanalization

Although myocardial contrast echocardiography (MCE) can evaluate microvascular perfusion abnormalities, its prognostic value is uncertain in acute anterior wall ST-Segment elevation myocardial infarction (STEMI) with successful epicardial recanalization. Therefore, the study aims to investigate the prognostic role of qualitative and quantitative MCE in acute anterior wall STEMI with successful epicardial recanalization. 153 STEMI patients were assessed by MCE within 7 days after successful epicardial recanalization. Qualitative perfusion parameters (microvascular perfusion score index, MPSI) and quantitative perfusion parameters (A, β, and Aβ) were acquired using a 17-segment model. And corrected A and Aβ were calculated. Patients were all followed for major adverse cardiovascular events (MACEs). During median follow-up of 27 (4) months, 39 (25.49%) patients experienced MACEs, while 114 (74.51%) were free from MACEs. Patients with MACEs had higher MPSI (1.65 ± 0.13 vs. No-MACEs 1.35 ± 0.20, P < 0.001), lower β (1.09 ± 0.19 s-1 vs. No-MACEs 1.34 ± 0.30 s-1, P < 0.001), corrected A (0.17 ± 0.03 dB vs. No-MACEs 0.19 ± 0.04 dB, P = 0.039) and lower corrected Aβ (0.19 ± 0.06 dB/s vs. No-MACEs 0.25 ± 0.08 dB/s, P < 0.001). MPSI of 1.44 provided an area under the curve (AUC) of 0.872, while β of 1.18 s-1 and corrected Aβ of 0.22 dB/s provided AUCs of 0.759 and 0.724, respectively. The combination of MPSI, β and corrected Aβ provided an increased AUC of 0.964 (all P < 0.05). Time-dependent ROC analysis showed that the AUCs of the MPSI, β, corrected Aβ and the combination at 1, 1.5 and 2 years indicated a strong predictive power for MACEs (AUC = 0.900/0.894/0.881 for MPSI, 0.648/0.704/0.732 for β, 0.674/0.686/0.722 for corrected Aβ, and 0.947/0.962/0.967 for the combination, respectively). Patients with MPSI < 1.44, β > 1.18 s-1, or corrected Aβ > 0.22 dB/s had lower event rate (all Log Rank P ≤ 0.001). MPSI, β, corrected Aβ, GLS and WBC were independent predictors of MACEs with adjusted hazard ratio of 34.41 (8.18-144.87), P < 0.001 for MPSI; 39.29 (27.46-65.44), P < 0.001 for β; 8.93 (1.46-54.55), P = 0.018 for corrected Aβ; 10.88 (2.83-41.86), P = 0.001 for GLS; and 1.43 (1.16-1.75), P = 0.001 for WBC. Qualitative and quantitative MCE can accurately predict MACEs in acute anterior wall STEMI with successful epicardial recanalization, and their combined predictive value is higher.

Assessment and Treatment for Coronary Microvascular Dysfunction by Contrast Enhanced Ultrasound

With growing evidence in clinical practice, the understanding of coronary syndromes has gradually evolved out of focusing on the well-established link between stenosis of epicardial coronary artery and myocardial ischemia to the structural and functional abnormalities at the level of coronary microcirculation, known as coronary microvascular dysfunction (CMD). CMD encompasses several pathophysiological mechanisms of coronary microcirculation and is considered as an important cause of myocardial ischemia in patients with angina symptoms without obstructive coronary artery disease (CAD). As a result of growing knowledge of the understanding of CMD assessed by multiple non-invasive modalities, CMD has also been found to be involved in other cardiovascular diseases, including primary cardiomyopathies as well as heart failure with preserved ejection fraction (HFpEF). In the past 2 decades, almost all the imaging modalities have been used to non-invasively quantify myocardial blood flow (MBF) and promote a better understanding of CMD. Myocardial contrast echocardiography (MCE) is a breakthrough as a non-invasive technique, which enables assessment of myocardial perfusion and quantification of MBF, exhibiting promising diagnostic performances that were comparable to other non-invasive techniques. With unique advantages over other non-invasive techniques, MCE has gradually developed into a novel modality for assessment of the coronary microvasculature, which may provide novel insights into the pathophysiological role of CMD in different clinical conditions. Moreover, the sonothrombolysis and the application of artificial intelligence (AI) will offer the opportunity to extend the use of contrast ultrasound theragnostics.

Effects of etibatide combined with emergency percutaneous coronary intervention on blood perfusion and cardiac function in patients with acute myocardial infarction

Objectives:

To investigate the effects of etibatide combined with emergency percutaneous coronary intervention (PCI) on blood perfusion and cardiac function in acute myocardial infarction (AMI) patients.

Methods:

This was a prospective, randomized, controlled study. From November 2015 to June 2019, 196 patients with ST-segment elevation myocardial infarction (STEMI) undergoing emergency PCI admitted to Baoding First Central Hospital were enrolled. The 196 STEMI patients were randomly divided into experimental group and control group. In the experimental group, STEMI patients were treated with emergency PCI + etibatide; while in the control group, only PCI was performed. Observation indexes included: general data, myocardial perfusion and cardiac function indexes and major adverse cardiac events (MACE).

Results:

There was no significant difference in general data between the two groups (P > 0.05). The rate of ST-segment resolution (STR) in the experimental group was better than that in the control group (P < 0.05). In myocardial contrast echocardiography (MCE), higher peak intensity (PI) and shorter time-to-peak (TP) were observed in the experimental group compared with the control group (P < 0.05). The platelet aggregation rate was compared between the two group at the time points of before PCI, after PCI and two hour after drug withdrawal, and there was no significant change in the platelet aggregation rate of the control group between different time points (before PCI, after PCI and two hour after drug withdrawal); while the platelet aggregation rate of the experimental group was significantly lower after PCI and two hour after drug withdrawal than that before PCI (P < 0.05), and an obviously decreased platelet aggregation rate was found in the experimental group(P < 0.05). After three months of follow-up, there was one case of MACE in the experimental group and 1 case of MACE in the control group, without any difference in the incidence of MACE between the two groups (P > 0.05).

Conclusion:

Etibatide combined with emergency PCI could improve myocardial reperfusion and cardiac function in patients with acute STEMI without increasing the incidence of MACE.

Feasibility of myocardial perfusion assessment with contrast echocardiography: can it improve recognition of significant coronary artery disease in the ICU?

BACKGROUND

Diagnosis of significant coronary artery disease (CAD) and acute coronary artery occlusion in ICU can be difficult, and an inappropriate intervention is potentially harmful. Myocardial contrast perfusion echo (MCPE) examines ultrasound contrast intensity replenishment curves in individual myocardial segments measuring peak contrast intensity and slope of return as an index of myocardial blood flow (units = intensity of ultrasound per second [dB/s]). MCPE could possibly serve as a triage tool to invasive angiography by estimating blood flow in the myocardium. We sought to assess feasibility in the critically ill and if MCPE could add incremental value to the clinical acumen in predicting significant CAD.

METHODS

This is a single-centre, prospective, observational study. Inclusion criteria were as follows: adult ICU patients with troponin I > 50 ng/L and cardiology referral being made for consideration of inpatient angiography. Exclusion criteria were as follows: poor echo windows (2 patients), known ischaemic heart disease, and contrast contraindications. Seven cardiologists and 6 intensivists blinded to outcome assessed medical history, ECG, troponin, and 2D echo images to estimate likelihood of significant CAD needing intervention (clinical acumen). Clinical acumen, quantitative MCPE, and subjective (visual) MCPE were assessed to predict significant CAD.

RESULTS

Forty patients underwent MCPE analysis, 6 (15%) had significant CAD, and median 11 of 16 segments (IQR 8-13) could be imaged (68.8% [IQR 50-81]). No adverse events occurred. A significant difference was found in overall MCPE blood flow estimation between those diagnosed with significant CAD and those without (3.3 vs 2.4 dB/s, p = 0.050). A MCPE value of 2.8 dB/s had 67% sensitivity and 88% specificity in detecting significant CAD. Clinical acumen showed no association in prediction of CAD (OR 0.6, p = 0.09); however, if quantitative or visual MCPE analysis was included, a significant association occurred (OR 17.1, p = 0.01; OR 23.0, p = 0.01 respectively).

CONCLUSIONS

MCPE is feasible in the critically ill and shows better association with predicting significant CAD vs clinical acumen alone. MCPE adds incremental value to initial assessment of the presence of significant CAD which may help guide those who require urgent angiography.

Myocardial contrast echocardiography in the diagnosis of postoperative takotsubo myocardiopathy: case report and literature review

Background

Takotsubo cardiomyopathy (TCM) is a brief ventricular dysfunction that usually occurs after emotional or physical stress. Here, we report a patient who underwent cardiac surgery and then developed TCM during the postoperative period.

Case presentation

A 51-year-old woman was admitted to our hospital complaining of chest tightness, palpitations and dyspnoea after activity. An echocardiogram performed by our hospital showed rheumatic heart disease (severe mitral stenosis and regurgitation) with normal cardiac function and wall motion. After mitral valve replacement, this patient developed heart failure with low blood pressure and tachycardia. Urgent bedside echocardiography demonstrated akinesis in the middle and apical segments of the left ventricle and a depressed ejection fraction (EF) of 36%. Myocardial contrast echocardiography (MCE) showed similar enhancement intensity in the basal, middle and apical segments. Quantitative analysis showed approximately equivalent maximum intensity in these regions. The diagnosis was considered TCM instead of myocardial infarction. Then, an intra-aortic balloon pump was inserted to maintain effective circulation and reduce the postcardiac load. Given ventilation therapy, postoperative anticoagulation therapy and anti-infection treatment, the patient recovered quickly. In the follow-up examination, the patient remained asymptomatic and showed normalization of ventricular wall motion in the apical segment.

Conclusion

This report presents a case of TCM in which MCE was used to demonstrate intact microvascular perfusion despite apical akinesis. This report might support the use of MCE as a substitute for invasive coronary angiography.

Interleukin 8 targeted contrast echocardiography is effective to evaluate myocardial ischemia-reperfusion injury in the rabbits

Interleukin 8 (IL-8) is an important pro-inflammatory cytokine that recruits neutrophil to the areas of inflammation and has been implicated in myocardial ischemia reperfusion injury (MIRI). This study aimed to apply IL-8 targeted myocardial contrast echocardiography (MCE) to evaluate MIRI in rabbits. MCE imaging with IL-8 targeted microbubbles (MB_IL-8) and control microbubbles (MB_c) was performed in 40 Japanese white rabbits after brief proximal left anterior descending (LAD) partial occlusion for 30 min and subsequent reperfusion for 30 min, 60 min, 120 min and 180 min. Electrocardiogram and regional wall motion were assessed during occlusion and reperfusion. MCE demonstrated that IL-8 level rapidly increased in reperfused myocardial tissue and reached the peak after 120 min of reperfusion and lasted to 180 min of reperfusion. ELISA showed that the tendency of MCE data to change with reperfusion time was the same as that of IL-8 content. Taken together, these results suggest that targeted MCE with IL-8 antibody provides a new approach to noninvasive evaluation of MIRI using ultrasound imaging techniques.

Quantitative segmental analysis of myocardial perfusion to differentiate stress cardiomyopathy from acute myocardial infarction: A myocardial contrast echocardiography study

BACKGROUND

Both stress cardiomyopathy (SCMP) and acute myocardial infarction (AMI) present with similar clinical symptoms and signs, and apical akinesis.

HYPOTHESIS

Quantitative segmental analysis of myocardial contrast echocardiography (MCE) helps to differentiate AMI from SCMP.

METHODS

Real-time MCE was performed in 33 consecutive patients who presented with an acute symptom/sign and a new apical akinesis on echocardiography. In 18 left ventricular (LV) myocardial segments, a replenishment curve was obtained in each segment to measure peak plateau myocardial contrast intensity (MCI) (A) and the replenishment curve slope (β). The calibrated MCI was also measured in each segment.

RESULTS

Among 33 patients, 22 were diagnosed with SCMP and 11 were diagnosed with AMI according to comprehensive diagnostic criteria. A, β, Aβ, and the calibrated MCI were lower in akinetic than in normokinetic segments in both the SCMP and AMI groups. In the akinetic segments, A, β, Aβ, and the calibrated MCI in SCMP patients were each higher than those in AMI patients. In patient-based analyses, areas under the ROC curves of A, β, Aβ, and the calibrated MCI for diagnosing AMI were 0.769, 0.607, 0.822, and 0.934, respectively. The optimal cutoff values to diagnose AMI were Aβ < 3.7 dB/sec (sensitivity 82%, specificity 82%) and a calibrated MCI < -23 dB (sensitivity 91%, specificity 95%).

CONCLUSIONS

Although myocardial perfusion is relatively reduced in the akinetic segments of SCMP, a quantitative segmental analysis of myocardial perfusion using MCE helps to discriminate AMI from SCMP.