Abstract 11465: Impact of a QTc Risk Score Advisory on Mortality in Intensive Care Units

Abstract

Introduction: Prolongation of the heart rate-corrected QT interval (QTc) is associated with increased mortality. We hypothesized that incorporation of a QTc prolongation risk score (QTc-RS) into a clinical decision support (CDS) advisory may reduce mortality in patients in intensive care units (ICUs). Objective: To evaluate the effectiveness of a QTc-RS risk score CDS on inpatient mortality in ICUs within hospitals in a wide geographical area. Methods: A QTc-RS CDS advisory incorporating a validated risk score using patient information available in the electronic health record was implemented throughout urban and rural facilities in the Banner Health system. Risk factors were assigned points as follows: female (1 point), age > 67 years (1), administration of a loop diuretic (1), diagnosis of acute myocardial infarction (2), serum K + ≤ 3.5 mEq/L (2), sepsis (3), diagnosis of heart failure (3), one medication with a known risk of torsades de pointes (TdP) (3), two or more medications with known risk of TdP (3), and a Fridericia-corrected QTc > 500 ms (4). The QTc-RS was automatically calculated in the background each time an order for medication with a known risk of TdP was initiated. The pre-implementation period consisted of hospitalized patients from January 1, 2020 to March 31, 2020, with QTc-RS ≥12. However, clinicians did not receive a QTc-RS CDS advisory when placing an order for a medication with a known risk of TdP for these patients. The post-implementation period was from April 1, 2020 to December 13, 2020 and included patients where clinicians received an advisory when placing an order for a medication with a known risk of TdP and the QTc-RS ≥12. Logistic regression was conducted to assess the impact of implementing the QTc-RS advisory on inpatient mortality. Results: We evaluated 620 unique hospitalized patients during the pre-implementation period and 3,112 hospitalized patients post-implementation of the CDS. Mortality was lower in the post-implementation cohort compared to that in the pre-implementation cohort (odds ratio =0.61, 95% confidence interval 0.49-0.76). Increasing QTc-RS was associated with increasing mortality [(OR=1.08 (1.02-1.14)]. Conclusion: Implementation of a QTc-RS CDS advisory was associated with lower mortality.