Baseline LV ejection fraction by cardiac magnetic resonance and 2D echocardiography after ST-elevation myocardial infarction - influence of infarct location and prognostic impact

Interaction between the left ventricular ejection fraction and left ventricular strain and its relationship with coronary stenosis

BACKGROUND

Coronary artery stenosis (CAS) is the most common type of heart disease and the leading cause of death in both men and women globally. CAS occurs when the arteries that supply blood to the heart muscle harden and become narrower due to plaque buildup - cholesterol and other material - on their inner walls. As a result, the heart muscle cannot receive the blood or oxygen it needs. Most heart attacks happen when a blood clot suddenly cuts off the hearts' blood supply, causing permanent heart damage.

AIM

To analyze the relationship between the left ventricular ejection fraction (LVEF), left ventricular strain (LVS), and coronary stenosis.

METHODS

A total of 190 participants were enrolled in this trail. The control group comprised 93 healthy individuals, and observation group comprised 97 patients with coronary heart disease who were hospitalized between July 2020 and September 2021. Coronary lesions were assessed using the Gensini score, and the LVEF and LVS were measured using magnetic resonance imaging (MRI). The interaction between the LVEF and LVS was examined using a linear regression model. The relationship between LVEF and coronary stenosis was examined using Spearman’s correlation.

RESULTS

The LVEF of the observation group was lower than that of the control group. The left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) of the observation group were significantly higher than those of the control group (P < 0.05). The longitudinal and circumferential strains (LS, CS) of the observation group were significantly higher than those of the control group; however, the radial strain (RS) of the observation group was significantly lower than that of the control group (P < 0.05). LVS, LS, and CS were significantly negatively correlated with the LVEF, and RS was positively correlated with the LVEF. There were significant differences in the LVEF, LVESV, and LVEDV of patients with different Gensini scores; the LVEF significantly decreased and the LVESV and LVEDV increased with increasing Gensini scores (P < 0.05). In the observation group, the LVEF was negatively correlated and the LVESV and LVEDV were positively correlated with coronary stenosis (P < 0.05).

CONCLUSION

The LVEF measured using MRI is significantly linearly correlated with LVS and negatively correlated with coronary stenosis.

Left Ventricular Adverse Remodeling in Ischemic Heart Disease: Emerging Cardiac Magnetic Resonance Imaging Biomarkers

Post-ischemic left ventricular (LV) remodeling is a biologically complex process involving myocardial structure, LV shape, and function, beginning early after myocardial infarction (MI) and lasting until 1 year. Adverse remodeling is a post-MI maladaptive process that has been associated with long-term poor clinical outcomes. Cardiac Magnetic Resonance (CMR) is the best tool to define adverse remodeling because of its ability to accurately measure LV end-diastolic and end-systolic volumes and their variation over time and to characterize the underlying myocardial changes. Therefore, CMR is the gold standard method to assess in vivo myocardial infarction extension and to detect the presence of microvascular obstruction and intramyocardial hemorrhage, both associated with adverse remodeling. In recent times, new CMR quantitative biomarkers emerged as predictive of post-ischemic adverse remodeling, such as T1 mapping, myocardial strain, and 4D flow. Additionally, CMR T1 mapping imaging may depict infarcted tissue and assess diffuse myocardial fibrosis by using surrogate markers such as extracellular volume fraction, which may predict functional recovery or risk stratification of remodeling. Finally, there is emerging evidence supporting the utility of intracavitary blood flow kinetic energy and hemodynamic features assessed by the 4D flow CMR technique as early predictors of remodeling.

Prognostic value of depressed cardiac index after STEMI: a phase-contrast magnetic resonance study

AIMS 

An invasively measured cardiac index (CI) of ≤2.2 L/min/m2 is one of the strongest prognostic indicators after ST-elevation myocardial infarction (STEMI), however, knowledge is mainly based on invasive evaluations performed in the pre-stent era. Velocity-encoded phase-contrast cardiac magnetic resonance (PC-CMR) allows non-invasive determination of CI.

METHODS AND RESULTS 

In this prospective study, CMR was performed in 406 stable and contemporarily revascularized patients a median of 3 days after STEMI. Forward stroke volume was assessed at the level of the ascending aorta by PC-CMR. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) were determined by cine CMR. Major adverse cardiac events (MACE) were defined as the composite of death, myocardial infarction, or hospitalization for heart failure. Median CI was 2.52 L/min/m2 and 27% of patients had ≤2.2 L/min/m2. Median LVEF was 53% and median GLS was -12.2%. During a median follow-up of 14.2 [95% confidence interval (95% CI) 13.6-14.7] months, 41 patients (10.1%) experienced a MACE. A depressed CI was significantly associated with MACE after adjustment for LVEF, GLS, Thrombolysis in Myocardial Infarction (TIMI) risk score, and infarct size [hazard ratio = 3.15 (95% CI 1.53-6.47); P = 0.002] and led to significant discrimination improvement [net reclassification improvement 0.61 (95% CI 0.25-0.97); P < 0.001].

CONCLUSIONS 

A CI of 2.2 L/min/m2 or less as measured by PC-CMR was present in 27% of clinically stable patients after STEMI and strongly and independently predicted medium-term MACE. The prognostic value of a depressed CI was superior and incremental to LVEF, GLS, TIMI risk score, and infarct size.

A prognostic nomogram for long-term major adverse cardiovascular events in patients with acute coronary syndrome after percutaneous coronary intervention

BACKGROUND

Accurate prediction of major adverse cardiovascular events (MACEs) is very important for the management of acute coronary syndrome (ACS) patients. We aimed to construct an effective prognostic nomogram for individualized risk estimates of MACEs for patients with ACS after percutaneous coronary intervention (PCI).

METHODS

This was a prospective study of patients with ACS after PCI from January 2013 to July 2019 (n = 2465). After removing patients with incomplete clinical information, a total of 1986 patients were randomly divided into evaluation (n = 1324) and validation (n = 662) groups. Predictors included in the nomogram were determined by a multivariate Cox proportional hazards regression model based on the training set. Receiver operating characteristic (ROC) curves and calibration curves were used to assess the discrimination and predictive accuracy of the nomogram, which were then compared with those of the classic models. The clinical utility of the nomogram was assessed by X-tile analysis and Kaplan-Meier curve analysis.

RESULTS

Independent prognostic factors, including lactate level, age, left anterior descending branch stenosis, right coronary artery stenosis, brain natriuretic peptide level, and left ventricular ejection fraction, were determined and contained in the nomogram. The nomogram achieved good areas under the ROC curve of 0.712-0.762 in the training set and 0.724-0.818 in the validation set and well-fitted calibration curves. In addition, participants could be divided into two risk groups (low and high) according to this model.

CONCLUSIONS

A simple-to-use nomogram incorporating lactate level effectively predicted 6-month, 1-year, and 4-year MACE incidence among patients with ACS after PCI.

Trimethylamine N-Oxide Was Not Associated With 30-Day Left Ventricular Systolic Dysfunction in Patients With a First Anterior ST-Segment Elevation Myocardial Infarction After Primary Revascularization: A Sub-analysis From an Optical Coherence Tomography Registry

Objective: Left ventricular systolic dysfunction (LVSD) after ST-segment elevation myocardial infarction (STEMI) is associated with poor outcome. Trimethylamine N-oxide (TMAO), a gut metabolite, is linked to cardiovascular diseases but its relationship with LVSD after STEMI remains unclear. The present study therefore aimed to investigate the relationship between TMAO and LVSD at 30 days after a first anterior STEMI.

Methods: This was a sub-study from the OCTAMI (Optical Coherence Tomography Examination in Acute Myocardial Infarction) registry. Eligible patients were included in current study if they: (1) presented with a first anterior STEMI; (2) had available baseline TMAO concentration; (3) completed a cardiovascular magnetic resonance examination at 30 days after STEMI. LVSD was defined as left ventricular ejection fraction < 50%. Associations between TMAO and left ventricular ejection fraction, infarct size and left ventricular global strain were examined.

Results: In total, 78 patients were included in final analysis. Overall, TMAO was moderately associated with peak cTnI (r = 0.27, p = 0.01), age (r = 0.34, p < 0.01), and estimated glomerular filtration rate (r = −0.30, p < 0.01). At 30-day follow-up, 41 patients were in the LVSD group and 37 in the non-LVSD group. Baseline TMAO levels were not significantly different between the two groups (LVSD vs. non-LVSD: median 1.9 μM, 25−75th percentiles 1.5–3.3 μM vs. median 1.9 μM, 25−75th percentiles 1.5–2.7 μM; p = 0.46). Linear regression analyses showed that TMAO was not associated with left ventricular ejection fraction, infarct size or left ventricular global strain at 30 days (all p > 0.05).

Conclusions: TMAO was not significantly correlated with 30-day LVSD in patients with a first anterior STEMI after primary revascularization.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03593928.