Retrospective 172 hospitalized patients, 83% treated and HCQ+AZ and 17% with HCQ, not finding a significant difference in QTc prolongation, but recommending careful monitoring for the use of HCQ+AZ; especially in males, patients with high-risk Tisdale score, and in patients who have baseline QTc interval ≥ 450 milliseconds.
Eftekhar et al., 1/26/2021, preprint, 6 authors.