The modified Selvester QRS score: Can we predict successful ST segment resolution in patients with myocardial infarction receiving fibrinolytic therapy?

Background: We sought to explore whether the simplified Selvester QRS scoring system could predict ST segment resolution in patients with first acute ST segment elevation myocardial infarction who receive pharmacological reperfusion therapy. Methods: We enrolled 60 consecutive patients admitted to the critical care unit with the diagnosis of first acute ST segment elevation myocardial infarction presenting within 24 hours from symptom onset, and eligible for reperfusion therapy. All patients received streptokinase in the usual dose regimen. Patients underwent resting high-quality 12-lead electrocardiogram recordings to calculate the modified QRS score and estimate the sum of ST segment elevation before (STE1) and 90 minutes after (STE2) streptokinase. The difference between STE1 and STE2 was then measured and accepted as the sum of ST segment resolution, expressed as ΣSTR. Patients were classified into two groups: those with ΣSTR ≥ 50% of STE1 (the resolution group) and those with ΣSTR < 50% (the non-resolution group). Results: The mean QRS score was significantly lower in the resolution group compared to the non-resolution group (2.88 ± 1.34 vs 5.93 ± 1.56, respectively, p < 0.001). There was a highly significant negative correlation between QRS score and ΣSTR with a correlation coefficient r = -0.76. Using a cut-off value of ≥ 4, the QRS score had a sensitivity of 93%, specificity of 72%, positive and negative predictive values of 74% and 92% respectively, for predicting ΣSTR < 50%. Conclusions: The Selvester QRS score can reliably predict adequate ST segment resolution in patients with first acute ST segment elevation myocardial infarction receiving fibrinolytic therapy, with a high sensitivity and an acceptable specificity. © 2010 Via Medica.