5PSQ-013 Analysis of the risk of QT interval prolongation in institutionalised elderly patients in a nursing home

Background and importance Prolongation of the QT interval in the ECG can trigger an arrhythmia (torsades de pointes) that usually resolves spontaneously, although sometimes it can cause ventricular fibrillation and sudden death. Drugs are a frequent cause of QT interval prolongation and therefore it is recommended that the risk of QT interval prolongation is assessed, especially in elderly polymedicated patients. Aim and objectives To determine the prevalence of patients in a nursing home (NH) with prescription of drugs with a defined and potential risk for producing prolongation of the QT interval, and to assess the concomitance of these drugs and history and/or cardiac pathologies. Material and methods A descriptive cross sectional study was conducted in all patients in a NH who had active electronic prescriptions. The main variable was percentage of patients treated with drugs with a defined and potential risk of QT interval prolongation (DR-QT and PR-QT, respectively), according to the levels of evidence in the AZCERT list. Concomitant prescription of these drugs in a single patient was also assessed. As secondary variables, we studied the main therapeutic groups prescribed with DR and PR-QT and the concomitance of their prescriptions along with a history and/or cardiac pathologies. Demographic, clinical and analytical data were obtained from the electronic clinical history and treatment data from the electronic prescription programme. Results As of 4 July 2019, 87 patients with active electronic prescriptions in a NH were selected. Average age was 66 years (52–101), 55.2% (48/87) were men and 70% were assisted (70/87). Among these patients, 13% were being treated with a DR-QT drug (11/87) and 13% with a PR-QT drug (11/87). Two patients were receiving a DR-QT and a PR-QT drug. Two patients were receiving two PR-QT drugs. The main therapeutic groups of DR-QT drugs were antidepressants (45%), antipsychotics (36%), antiarrhythmics and other (9%). The main therapeutic groups of PR-QT drugs were antipsychotics (38%), antidepressants (31%), genitourinary (15%), musculoskeletal and others (8%). Three patients treated with DR-QT drugs and six patients treated with PR-QT drugs had a history and/or cardiac pathologies. No patient receiving a DR and a PR drug had a history and/or cardiac pathologies. Two patients who were receiving two PR-QT drugs had a history and/or cardiac pathologies, mainly arterial hypertension. Conclusion and relevance One-quarter of institutionalised elderly patients in a NH were being treated with DR and/or PR-QT drugs, in almost half of the cases with a history and/or cardiac pathology. The main therapeutic groups involved were antidepressants and antipsychotics. References and/or acknowledgements No conflict of interest.