Assessing the Risk of QT Prolongation in a Psychiatric Inpatient Cohort: A Retrospective Cross-Sectional Study.

Area of Science:

• Pharmacology
• Cardiology
• Psychiatry

Background:

• QT prolongation is a serious adverse drug reaction.
• Risk assessment of QT-prolonging drugs is standard in psychotropic medication reviews.
• The clinical utility of these assessments remains unclear.

Purpose of the Study:

• To determine if QT prolongation (QTc > 480 ms) occurs in psychiatric inpatients identified as high-risk by drug regimen assessment.
• To evaluate the predictive value of known risk factors for QT prolongation.

Main Methods:

• Electronic health records of 799 psychiatric inpatients were reviewed.
• Data were collected from September 2016 to December 2018 in Region Zealand, Denmark.
• Electrocardiograms (ECGs) were analyzed for patients with and without identified QT prolongation risk.

Main Results:

• Median age was 49 years, with patients on 9 medications and a QT-prolonging drug load of 3 daily defined dosages.
• 33 cases of QT prolongation were identified, equally distributed between risk groups (290 ECGs from high-risk, 190 from low-risk).
• Advanced age (OR 3.27) and cardiovascular comorbidity (OR 3.53) predicted QT prolongation, but drug load did not.

Conclusions:

• Drug review-identified QT prolongation risk is uncommon in psychiatric inpatients.
• Non-pharmacological factors like age and cardiovascular health are more significant predictors of QT prolongation than medication load.