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

Background 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. Objective To evaluate the sensitivity and specificity of the Tisdale-score with regard to detected QTc prolongations in patients prescribed systemic azole antifungals. Methods 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. Results 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%. Conclusion 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.