# Tisdale-score-based risk stratification of QTc prolongations in hospitalized patients receiving azole antifungal therapy—a retrospective study

## TL;DR

This study evaluates how well the Tisdale-score predicts QTc prolongation in patients taking azole antifungals, finding it highly sensitive but low in specificity.

## Contribution

The study applies and validates the Tisdale-score in patients receiving azole antifungals for QTc prolongation risk.

## Key findings

- The Tisdale-score showed 100% sensitivity in identifying QTc prolongation risk.
- Only 4.7% of patients had relevant QTc prolongations despite high QT-drug use.
- The median Tisdale-score was 7, indicating moderate risk in the studied population.

## Abstract

QTc prolongation can trigger potentially lethal arrhythmias. Almost all azole antifungals, which are used in vulnerable patients, prolong the QTc interval and thus, may increase arrhythmia risk. The Tisdale-risk-score allows to identify patients at risk for drug-induced QTc prolongation but has not yet been investigated in this patient population.

To evaluate the sensitivity and specificity of the Tisdale-score with regard to detected QTc prolongations in patients prescribed systemic azole antifungals.

For six months (12/23-05/24), prescriptions of systemic azole antifungals were retrospectively recorded in adult inpatients of all medical specialties of a university hospital. Risk factors for QTc prolongation, including concomitant drugs and ECGs, were documented and the Tisdale-score and its sensitivity and specificity were calculated.

In the study period, 319 systemic azole prescriptions (cases) were recorded for 259 patients. The median age of all cases was 61 years, 45% (143) were female. Including the systemic azole, a prescription of ≥2 QT-drugs was present in 283 (89%) cases. The median Tisdale-score was 7 (moderate risk). ECGs after azole initiation were available in 149 cases. Out of these, relevant QTc prolongations occurred in 7 cases (4.7%). Sensitivity of the Tisdale-score was 100%, specificity 30%.

Patients prescribed systemic azole antifungals are at risk of QTc prolongation due to regular use of multiple QT-drugs. However, relevant QTc prolongations were rare in the patient population studied. The Tisdale-score achieved a good sensitivity for the identification of patients at risk for QTc prolongation.