The 6-SD semiautomated technique accurately quantified acute (24.9±14.0%LV, p=0.81) and chronic MI size (17.2±9.7%LV, p=0.88) compared to manual assessment in patients with reperfused STEMI.
Observational (n=40)
Which semiautomated CMR technique is most accurate for quantifying acute and chronic myocardial infarction size compared to manual assessment in patients with reperfused STEMI?
The 6-SD semiautomated technique is the most accurate for quantifying acute and chronic MI size by CMR and should be preferred in clinical trials.
AIMS: The four most promising semiautomated techniques (5-SD, 6-SD, Otsu and the full width half maximum (FWHM)) were compared in paired acute and follow-up cardiovascular magnetic resonance (CMR), taking into account the impact of microvascular obstruction (MVO) and using automated extracellular volume fraction (ECV) maps for reference. Furthermore, their performances on the acute scan were compared against manual myocardial infarct (MI) size to predict adverse left ventricular (LV) remodelling (≥20% increase in end-diastolic volume). METHODS: 40 patients with reperfused ST segment elevation myocardial infarction (STEMI) with a paired acute (4±2 days) and follow-up CMR scan (5±2 months) were recruited prospectively. All CMR analysis was performed on CVI42. RESULTS: Using manual MI size as the reference standard, 6-SD accurately quantified acute (24.9±14.0%LV, p=0.81, no bias) and chronic MI size (17.2±9.7%LV, p=0.88, no bias). The performance of FWHM for acute MI size was affected by the acquisition sequence used. Furthermore, FWHM underestimated chronic MI size in those with previous MVO due to the significantly higher ECV in the MI core on the follow-up scans previously occupied by MVO (82 (75-88)% vs 62 (51-68)%, p<0.001). 5-SD and Otsu were precise but overestimated acute and chronic MI size. All techniques were performed with high diagnostic accuracy and equally well to predict adverse LV remodelling. CONCLUSIONS: 6-SD was the most accurate for acute and chronic MI size and should be the preferred semiautomatic technique in randomised controlled trials. However, 5-SD, FWHM and Otsu could also be used when precise MI size quantification may be adequate (eg, observational studies).
Bulluck et al. (Thu,) conducted a observational in reperfused ST segment elevation myocardial infarction (STEMI) (n=40). Semiautomated techniques for quantifying MI (5-SD, 6-SD, Otsu, FWHM) vs. Manual myocardial infarct (MI) size was evaluated on Accuracy of acute and chronic MI size quantification compared to manual MI size. The 6-SD semiautomated technique accurately quantified acute (24.9±14.0%LV, p=0.81) and chronic MI size (17.2±9.7%LV, p=0.88) compared to manual assessment in patients with reperfused STEMI.