August 19, 2019Open Access
Baseline LV ejection fraction by cardiac magnetic resonance and 2D echocardiography after ST-elevation myocardial infarction – influence of infarct location and prognostic impact
Key Result
A reduced left ventricular ejection fraction of <52% assessed by either 2D echocardiography or cardiac magnetic resonance similarly predicted major adverse cardiac events.
Study Design
Type
Observational (n=221)
Blinding
Single-blind
Multicenter
No
Structured PICO
Does 2D echocardiography accurately measure LVEF and predict MACE compared to cardiac magnetic resonance in patients after STEMI?
P
Population
221 patients after ST-elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention
I
Intervention
2D echocardiography (2DE) for LVEF measurement
C
Comparator
Cardiac magnetic resonance (CMR) for LVEF measurement
O
Outcome
Comparability of LVEF measurements and prediction of Major adverse cardiac events (MACE: composite of death, myocardial infarction or hospitalisation for heart failure)composite
2D echocardiography underestimates LVEF compared to CMR after non-anterior STEMI, but both modalities offer similar prognostic value for MACE when an LVEF cutoff of <52% is used.
Main Result
Effect estimate: HR 2.57 (95% CI 1.1-6.2)
p-value: p=0.036
Limitations
- A significant number of echocardiograms were excluded due to low imaging quality.
- Early measurements of LVEF after STEMI can be misleading due to increased contractility in uninvolved territories.
- Exams were not truly sequential, so haemodynamic differences between exams cannot be fully ruled out.
- Small number of patients with severely reduced LVEF limits extrapolation to this subgroup.
- Lack of data regarding myocardial strain.
Abstract
OBJECTIVES: The comparability of left ventricular ejection fraction (LVEF) measurements by cardiac magnetic resonance (CMR) and 2D echocardiography (2DE) early after ST-elevation myocardial infarction (STEMI) remains unclear. METHODS: In this study, LVEF measured by CMR and 2DE (Simpson's method) were compared in 221 patients after STEMI treated by primary percutaneous coronary intervention. 2DE image quality was systematically assessed and studies reported by an accredited examiner. Intermodality agreement was assessed by the Bland-Altman method. Major adverse cardiac events (MACE) were defined as the composite of death, myocardial infarction or hospitalisation for heart failure. Patients were followed up for a median of 40.9 months (IQR 28.1-56). RESULTS: After non-anterior STEMI, LVEF measurements by 2DE (single and biplane) were consistently underestimated in comparison to CMR (CMR 55.7 ± 9.5% vs. 2DE-4CV 49 ± 8.2% (p = 0.06), 2DE-2CV 52 ± 8% (p < 0.001), 2DE-biplane 53.5 ± 7.1% (p = 0.01)). After anterior STEMI, there was no significant difference in LVEF measurements by 2DE and CMR with acceptable limits of agreement (CMR 49 ± 11% vs. 2DE-4CV 49 ± 8.2% (p = 0.8), 2DE-2CV 49 ± 9.2% (p = 0.9), 2DE-biplane 49.6 ± 8% (p = 0.5)). In total, 15% of patients experienced a MACE during follow-up. In multivariate Cox regression analysis, reduced LVEF (< 52%) as assessed by either 2DE or CMR was predictive of MACE (2DE HR = 2.57 (95% CI 1.1-6.2), p = 0.036; CMR HR = 2.51 (95% CI 1.1-5.7), p = 0.028). CONCLUSIONS: At baseline after non-anterior STEMI, 2D echocardiography significantly underestimated LVEF in comparison to CMR, whereas after anterior infarction, measurements were within acceptable limits of agreement. Both imaging modalities offered similar prognostic values when a reduced LVEF < 52% was applied. KEY POINTS: • After non-anterior STEMI, 2D-echocardiography significantly underestimated LVEF compared with cardiac MRI • An ejection fraction of < 52% in the acute post-infarct period by both 2D echocardiography and CMR offered similar prognostic values.