Drug-Induced Effects on Other ECG Parameters

The TQT study is formally powered to exclude a small (around 5 ms) QTc prolongation. The variability of other ECG parameters (such as the PR and QRS intervals) are in fact lower than for the QTc interval, and it has become increasingly apparent that these studies also can and should be used for assessment of other ECG effects. These data, unfortunately, are not always given in publications on TQT studies, which makes it difficult to independently evaluate the QTc effect, or lack thereof. As an example, there is no mention of effects on heart rate, PR, or QRS interval in the publication on the TQT study with liraglutide (Chatterjee et al. 2009), 

It seems prudent to analyze all ECG parameters in TQT studies using the same approach as for QTc, i.e., the placebo-corrected, change-from-baseline across timepoints after dosing, which also recently have been highlighted by IRT in 

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