<P> Since 2005, the FDA and European regulators have required that nearly all new molecular entities be evaluated in a Thorough QT (TQT) study to determine a drug's effect on the QT interval . The TQT study serves to assess the potential arrhythmia liability of a drug . Traditionally, the QT interval has been evaluated by having an individual human reader measure approximately nine cardiac beats per clinical timepoint . However, a number of recent drug approvals have used a highly automated approach, blending automated software algorithms with expert human readers reviewing a portion of the cardiac beats, to enable the assessment of significantly more beats per timepoint in order to improve precision and reduce cost . As the pharmaceutical industry has gained experience in performing TQT studies, it has also become evident that traditional QT correction formulas such as QTcF, QTcB, and QTcLC may not always be suitable for evaluation of drugs impacting autonomic tone . Current efforts are underway by industry and regulators to consider alternative methods to help evaluate QT liability in drugs affecting autonomic tone, such as QT beat - to - beat and Holter - bin methodologies . </P> <P> Electrocardiography is a safe and noninvasive tool that can be used to identify those with a higher risk of mortality . In the general population, there has been no consistent evidence that prolonged QTc interval in isolation is associated with an increase in mortality from cardiovascular disease . However, several studies have examined prolonged QT interval as a predictor of mortality for diseased subsets of the population . </P> <P> Rheumatoid arthritis is the most common inflammatory arthritis . Studies have linked rheumatoid arthritis with increased death from cardiovascular disease . In a 2014 study, Panoulas et al. found a 50 ms increase in QTc interval increased the odds of all - cause mortality by 2.17 in patients with rheumatoid arthritis . Patients with the highest QTc interval (> 424 ms) had higher mortality than those with a lower QTc interval . The association was lost when calculations were adjusted for C - reactive protein levels . The researchers proposed that inflammation prolonged the QTc interval and created arrhythmias that were associated with higher mortality rates . However, the mechanism by which C - reactive protein is associated with the QTc interval is still not understood . </P> <P> Compared to the general population, type 1 diabetes may increase the risk of mortality, due largely to an increased risk of cardiovascular disease . Almost half of patients with type 1 diabetes have a prolonged QTc interval (> 440 ms). Diabetes with a prolonged QTc interval was associated with a 29% mortality over 10 years in comparison to 19% with a normal QTc interval . Anti-hypertensive drugs increased the QTc interval, but were not an independent predictor of mortality . </P>

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