Microvascular obstruction detected by cardiac MRI after AMI for the prediction of LV remodeling and MACE: A meta-analysis of prospective trials

The evaluation of coronary microvascular obstruction in patients with STEMI by cardiac magnetic resonance T2-STIR image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography

This study was designed to assess coronary microvascular obstruction (MVO) in patients with acute ST-segment elevation myocardial infarction (STEMI) by cardiac magnetic resonance T2-weighted short tau inversion recovery (T2-STIR) image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography (LDDSE-LS2D-STE). 32 patients were enrolled to perform cardiac magnetic resonance and echocardiography 5-7 days after primary percutaneous coronary intervention. Infarcted myocardium was categorized into MVO⁺ group and MVO^- group by late gadolinium enhancement as gold standard. At T2-weighted image, the area of hyper-intense region and hypo-intense core inside were marked as A1, A2 and A2/A1 > 0 represented MVO. Strain parameters were composed of longitudinal strain (LS), circumferential strain and radial strain at rest and dobutamine stress. There were 94 MVO⁺ segments, 136 MVO^- segments according to gold standard. 96 segments had hypo-intense core at T2-STIR image. The sensitivity and specificity of T2-STIR in detecting MVO were 91.49 and 92.65%. Endocardial LS was superior to other parameters, and stress endocardial LS was higher than that of resting endocardial LS (sensitivity: 77.11% vs 72.29%, specificity: 93.28% vs 83.19%, AUC: 0.87 vs 0.82, P < 0.05). The combination of T2-STIR and stress endocardial LS in parallel test could improve sensitivity significantly (98.05% vs 91.49%). T2-STIR has higher diagnostic value in detecting MVO with some limitations. However, LDDSE-LS2D-STE with cost-effective and handling may be a good alternative to T2-STIR. It provides additional and reliable diagnostic tools to identify MVO in STEMI patients after reperfusion.

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.

Detection of Left Ventricular Thrombi on Cardiac Magnetic Resonance Viability Studies

Objective

To highlight detection of left ventricular thrombi on cardiac magnetic resonance (CMR) viability studies.

Method

This retrospective observational study was conducted in the Radiology Department at our Hospital in Dhahran, from April 2015-2019. All recently re-perfused (post-percutaneous coronary intervention/PCI) patients with ST-segment elevation myocardial infarctions (STEMI), having low ejection fractions (<40%), impaired LV functions or abnormal wall motions on transthoracic echocardiographies (TTEs), who underwent cardiac magnetic resonance (CMR) imaging viability studies were included. Patients with incomplete or limited studies (due to artifacts), previous coronary artery bypass graft (CABG), those who lost follow-ups, and those who were contraindicated or unfit for MRIs were excluded. An area of low signal intensity with no late gadolinium enhancement (LGE) was defined as thrombus on MR imaging, and two radiologists reached consensus report for the diagnoses. Patients with anterior or non-anterior wall MI were documented, and their ejection fractions were recorded. Percentage estimation of LV thrombi as detected on CMR studies was made. Any complications (like MI, stroke or death) that occurred within one year of diagnoses were documented. A Chi-square was used to determine association.

Results

Of the 125 patients, most were men (71.2%) with a mean age of 56.78 years. Eleven patients had left ventricular thrombi (8.8%), and most of these were anterior wall infarctions with low ejection fractions (<40%). Three out of 11 patients with LV thrombi developed complications versus 3 out of 114 without LV thrombi (P- value, .0005).

Conclusion

Left ventricular thrombi can be detected on cardiac viability studies in recently re-perfused STEMI patients and may possibly predict the risk of complications.

Clinical associations of microvascular obstruction and intramyocardial hemorrhage on cardiovascular magnetic resonance in patients with acute ST segment elevation myocardial infarction (STEMI): An observational cohort study

Acute myocardial infarction (AMI) is recognized as being a life-threatening event. Both microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) have been recognized as poor prognostic factors in myocardial infarct (MI) since they adversely affect left ventricular remodeling. MVO refers to small vessels changes that prevent adequate tissue perfusion despite revascularization whereas IMH is a severe form of MVO. A limited number of studies have demonstrated the segmental intervention time and the clinical factors in the presence of MVO and IMH. Therefore, we aimed in this study to determine the correlations of the intervention-associated and clinical indexes with malignant cardiovascular magnetic resonance (CMR) signs in patients with AMI.Sixty-three patients with STEMI who underwent primary percutaneous coronary intervention (PPCI) within 12 hours were included in this study. A 3.0-T CMR scan was prescribed, and the subsequent image analysis was conducted by researchers blinded to the clinical index results. Late-gadolinium enhancement (LGE) and T2* sequences were mainly used for MVO and IMH identification and quantification.Patients exhibiting both MVO and IMH had the highest level of LGE (P < .001) and were significantly more frequently assigned to a pre-PPCI thrombolysis in myocardial infarction (TIMI) flow class of 0 (n=25, 89.3%). The MVO size correlated positively with the IMH size (r = 0.81, P < .01). A pre-PPCI TIMI flow class of 0 was found to reliably predict the presence of IMH (P < .001). Patients who received the intervention 4 to 6 hours after MI onset were more likely to exhibit MVO and IMH, although this trend was not statistically significant.We showed in our study that both MVO and IMH correlated with the degree of AMI and the pre-PPCI coronary flow, and both tended to occur more frequently in cases involving an interval of 4 to 6 hours between the onset of MI and the intervention. CMR is a reliable method for assessing MVO and IMH and its imaging features following gadolinium administration are characteristic. These findings stress the importance of using CMR in evaluating and improving the outcome of the medical management.

Role of cardiovascular magnetic resonance in acute and chronic ischemic heart disease

Cardiovascular magnetic resonance (CMR) is a multi-parametric, multi-planar, non-invasive imaging technique, which allows accurate determination of biventricular function and precise myocardial tissue characterization in a one-stop-shop technique, free from the use of ionizing radiations. Though CMR has been increasingly applied over the last two decades in every-day clinical practice, its widest application has been in the assessment of ischemic cardiomyopathy.

Cardiac remodeling following reperfused acute myocardial infarction is linked to the concomitant evolution of vascular function as assessed by cardiovascular magnetic resonance

BACKGROUND

Left ventricular (LV) remodeling following acute myocardial infarction (MI) is difficult to predict at an individual level although a possible interfering role of vascular function has yet to be considered to date. This study aimed to determine the extent to which this LV remodeling is influenced by the concomitant evolution of vascular function and LV loading conditions, as assessed by phase-contrast Cardiovascular Magnetic Resonance (CMR) of the ascending aorta.

METHODS

CMR was performed in 121 patients, 2-4 days after reperfusion of a first ST-segment elevation myocardial infarction and 6 months thereafter. LV remodeling was: (i) assessed by the 6-month increase in end-diastolic volume (EDV) and/or ejection fraction (EF) and (ii) correlated with the indexed aortic stroke volume (mL.m-2), determined by a CMR phase-contrast sequence, along with derived functional vascular parameters (total peripheral vascular resistance (TPVR), total arterial compliance index, effective arterial elastance).

RESULTS

At 6 months, most patients were under angiotensin enzyme converting inhibitors (86%) and beta-blockers (84%) and, on average, all functional vascular parameters were improved whereas blood pressure levels were not. An increase in EDV only (EDV+/EF-) was documented in 17% of patients at 6 months, in EF only (EDV-/EF+) in 31%, in both EDV and EF (EDV+/EF+) in 12% and neither EDV nor EF (EDV-/EF-) in 40%. The increase in EF was mainly and independently linked to a concomitant decline in TPVR (6-month change in mmHg.min.m2.L-1, EDV-/EF-: +1 ± 8, EDV+/EF-: +3 ± 9, EDV-/EF+: -7 ± 6, EDV+/EF+: -15 ± 20, p < 0.001) while the absence of any EF improvement was associated with high persisting rates of abnormally high TPVR at 6 months (EDV-/EF-: 31%, EDV+/EF-: 38%, EDV-/EF+: 5%, EDV+/EF+: 13%, p = 0.007). By contrast, the 6-month increase in EDV was mainly dependent on cardiac as opposed to vascular parameters and particularly on the presence of microvascular obstruction at baseline (EDV-/EF-: 37%, EDV+/EF-: 76%, EDV-/EF+: 38%, EDV+/EF+: 73%, p = 0.003).

CONCLUSION

LV remodeling following reperfused MI is strongly influenced by the variable decrease in systemic vascular resistance under standard care vasodilating medication. The CMR monitoring of vascular resistance may help to tailor these medications for improving vascular resistance and consequently, LV ejection fraction.

TRIAL REGISTRATION

NCT01109225 on ClinicalTrials.gov site (April, 2010).

Design and rationale of a multicentre, randomised, double-blind, placebo-controlled clinical trial to evaluate the effect of vitamin D on ventricular remodelling in patients with anterior myocardial infarction: the VITamin D in Acute Myocardial Infarction (VITDAMI) trial

INTRODUCTION

Decreased plasma vitamin D (VD) levels are linked to cardiovascular damage. However, clinical trials have not demonstrated a benefit of VD supplements on left ventricular (LV) remodelling. Anterior ST-elevation acute myocardial infarction (STEMI) is the best human model to study the effect of treatments on LV remodelling. We present a proof-of-concept study that aims to investigate whether VD improves LV remodelling in patients with anterior STEMI.

METHODS AND ANALYSIS

The VITamin D in Acute Myocardial Infarction (VITDAMI) trial is a multicentre, randomised, double-blind, placebo-controlled trial. 144 patients with anterior STEMI will be assigned to receive calcifediol 0.266 mg capsules (Hidroferol SGC)/15 days or placebo on a 2:1 basis during 12 months.

PRIMARY OBJECTIVE

to evaluate the effect of calcifediol on LV remodelling defined as an increase in LV end-diastolic volume ≥10% (MRI).

SECONDARY OBJECTIVES

change in LV end-diastolic and end-systolic volumes, ejection fraction, LV mass, diastolic function, sphericity index and size of fibrotic area; endothelial function; plasma levels of aminoterminal fragment of B-type natriuretic peptide, galectin-3 and monocyte chemoattractant protein-1; levels of calcidiol (VD metabolite) and other components of mineral metabolism (fibroblast growth factor-23 (FGF-23), the soluble form of its receptor klotho, parathormone and phosphate). Differences in the effect of VD will be investigated according to the plasma levels of FGF-23 and klotho. Treatment safety and tolerability will be assessed. This is the first study to evaluate the effect of VD on cardiac remodelling in patients with STEMI.

ETHICS AND DISSEMINATION

This trial has been approved by the corresponding Institutional Review Board (IRB) and National Competent Authority (Agencia Española de Medicamentos y Productos Sanitarios (AEMPS)). It will be conducted in accordance with good clinical practice (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use - Good Clinical Practice (ICH-GCP)) requirements, ethical principles of the Declaration of Helsinki and national laws. The results will be submitted to indexed medical journals and national and international meetings.

TRIAL REGISTRATION NUMBER

NCT02548364; Pre-results.

Magnetic resonance imaging in interventional therapy of patients with acute myocardial infarction prior to and after treatment

The aim of the study was to investigate the cardiac magnetic resonance (CMR) imaging in interventional therapy of patients with acute myocardial infarction prior to and after treatment. Fifty-six cases of AMI patients with elective treatment by percutaneous coronary intervention (PCI) were continuously selected. Patients with an incidence of 7–10 days were treated with CMR and echocardiography to evaluate the quality of myocardial infarction, visual score method (VSM), wall motion score abnormality, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF). Patients with an incidence of 10–14 days were treated with PCI, and CMR and echocardiography were evaluated after 6 months, after which the occurrence of major adverse cardiac events (MACE) were compared. The infarction quality, VSM score and wall motion abnormality (WMA) score were significantly reduced following surgery, and the difference was statistically significant (P<0.05). Ultrasound evaluation of LVEDD, LVESD, and LVEF prior to and after surgery was compared, and the difference was not statistically significant (P>0.05). Evaluation of the magnetic resonance imaging (MRI) in LVEDD prior to surgery was increased compared with that of the ultrasound in LVEDD, whereas MRI in LVESD and LVEF was decreased compared to that of the ultrasound obtained for LVESD and LVEF. Additionally, postoperative LVEDD was reduced compared with preoperative LVEDD, whereas LVEF was increased, and the difference was statistically significant (P<0.05). However, the evaluation of LVESD using the two methods exhibited no significant change. MACE occurred in 7 (12.5%) of 56 cases. The infarction quality of patients in the MACE group following surgery indicated that VSM and WMA scores were significantly higher than the group without MACE, while LVEF was lower than the MACE group following surgery, and the difference was statistically significant (P<0.05), albeit the ultrasound results of LVEF indicated no difference. In conclusion, CMR evaluation of AMI patients with elective PCI treatment in myocardial remodeling and cardiac function were more sensitive and accurate than with cardiac ultrasound.

Heart rate and left ventricular adverse remodelling after ST-elevation myocardial infarction

BACKGROUND

Discharge heart rate (HR) following ST-elevation myocardial infarction (STEMI) is a predictor of adverse left ventricular remodelling (LVR). However, the prognostic relevance of HR values in the earlier phase after revascularization is unknown. We aimed to investigate resting HR assessed at different time points during hospital stay following STEMI for the prediction of LVR.

METHODS

In this prospective observational study of 143 consecutive STEMI patients, HR was measured serially on admission (AHR), at day 1 (HRd1) and 2 (HRd2) following revascularization and finally at discharge (DHR). Cardiac magnetic resonance (CMR) scans were performed at baseline and 4months thereafter to evaluate LVR and major CMR determinants of LVR (infarct size, microvascular obstruction). LVR was defined as ≥15% increase of left ventricular end-diastolic volume.

RESULTS

Twenty-nine patients (20%) have developed LVR. HRd1 (80[72-88] vs. 71[62-79]bpm, p=0.003), HRd2 (74[64-83] vs. 67[59-78]bpm, p=0.04), DHR (74[62-81] vs. 64[58-73] bpm, p=0.008) and the mean HR of all measurements (76[68-82] vs. 67[60-77]bpm, p=0.004) were significantly higher in patients with LVR, whereas admission HR (75[68-85] vs. 70[60-82]bpm, p=0.12) did not differ significantly. The associations for all post-admission HRs remained significant after adjustment for clinical (high-sensitivity cardiac troponin T and C-reactive protein, left anterior descending artery as culprit) and CMR (infarct size, microvascular obstruction, ejection fraction) predictors of LVR. The predictive values of the post-admission HRs were equivalent (area under the curve differences: all p>0.05).

CONCLUSION

Besides DHR, resting HR values in the early stage following reperfusion are independent predictors of LVR after STEMI.