Evaluation of QT prolongation and arrhythmias in drug-resistant tuberculosis patients receiving bedaquiline-containing regimen: a prospective observational study in Eastern India

Background: Preliminary studies on bedaquiline (BDQ) for drug-resistant tuberculosis (DR-TB) treatment have shown variable incidences of QT interval changes. Validating these findings across diverse ethnic and geographic groups is essential for ensuring the safety and efficacy of BDQ therapy. Methods: A 1-year prospective observational study was conducted on a group of 50 participants. QT prolongation, arrhythmias, and other adverse events were evaluated in relation to clinical outcomes, in accordance with programmatic management of drug resistant tuberculosis (PMDT) 2019 guidelines. QT intervals were monitored using the corrected QT interval calculated by the Fridericia formula (QTcF) throughout the study period. Results: Out of 50 patients, 6 (12%) developed QT prolongation between days 4 and 10 of treatment initiation, comprising two males and four females; however, no arrhythmias were observed in these cases. Four patients had grade 1 and two had grade 2 QT prolongation without clinical symptoms or electrolyte imbalances. Treatment was temporarily paused for 4 days in one patient with a QT interval >500 milliseconds. Clinical improvement and sputum conversion occurred in 99% of patients, while 8 (16%) patients died during the study period, all with recent negative sputum cultures. Conclusion: BDQ-containing regimens are effective in DR-TB patients, though they may lead to asymptomatic QT prolongation in a limited number of cases. Further studies are recommended to generalize these findings to broader populations.