Comparison between contrast-enhanced magnetic resonance imaging and Selvester QRS scoring system in estimating changes in infarct size between the acute and chronic phases of myocardial infarction

Abstract

Background: The Selvester QRS score was developed as a method to estimate infarct size (IS) using the ECG and has been validated during the prereperfusion era. Few comparisons exist with contrast-enhanced magnetic resonance imaging (ceMRI) in reperfused patients. This study evaluates the ability of the Selvester QRS score to estimate serial changes in IS during the acute and chronic phases of the infarct evolution in patients who have received reperfusion therapy.

Methods: Thirteen patients with acute myocardial infarction underwent serial ceMRI studies in the acute (<1 week) and chronic phase (>2 months) after their initial myocardial infarction. QRS scoring was performed on the corresponding ECGs. The correlation between ceMRI measurement and QRS score estimation of IS was determined at both time points and for the difference between the two phases.

Results: The mean IS was 20.1 +/- 11.0% of total left ventricular mass (% LV) in the acute phase and 13.3 +/- 6.4% LV in the chronic phase ceMRI. The mean IS estimated by Selvester QRS score in the acute and chronic phases were 18.7 +/- 8.2% and 16.4 +/- 8.5% LV, respectively. A modest correlation was found for the acute (r = 0.57) and chronic phase IS (r = 0.54). However, there was no correlation for the difference in IS between the acute and chronic phases.

Conclusions: In this pilot study, the Selvester QRS score correlates modestly to IS by ceMRI during both the acute and chronic phases of the infarction process. The serial changes over time in the Selvester QRS score and IS by ceMRI show no correlation.

Figure 1

The 50‐criteria/31‐point Selvester QRS scoring system. Each of the 50 QRS criteria correspond to approximately 3% of the left ventricular mass. Brackets: only the criterion yielding the highest amount of points is counted.

Figure 2

Mean infarct sizes measured by ceMRI and estimated by Selvester QRS score, in the acute (<1 week) and chronic (>2 months) phase after acute myocardial infarction. % LV = percentage of left ventricular mass; NS = not significant.

Figure 3

Top: correlation between infarct size measurements by the Selvester QRS score and contrast‐enhanced MRI (ceMRI) in the acute (left) and chronic phases (mid) after acute myocardial infarction, and the change (right) between these two measurements. The two patients with the largest time intervals between ceMRI and ECG are depicted as a diamond. Bottom: Bland‐Altman plots of these correlations.

Figure 4

Patient numbers in groups divided by increase or decrease by Selvester QRS score and ceMRI. Increase or decrease was defined as a change of >1 point in Selvester QRS score or >3% LV on ceMRI.