Prognostic significance of corrected QT and corrected JT interval for incident coronary heart disease in a general...

Area of Science:

• Cardiology
• Electrophysiology
• Public Health

Background:

• The heart rate-corrected QT interval (QTc) traditionally assesses ventricular repolarization but is unreliable with QRS duration ≥120 ms.
• Increased QRS duration complicates QTc interpretation, necessitating alternative methods for repolarization assessment.
• The JT interval, and specifically the corrected JT interval (JTc), has been proposed as a more accurate measure in such cases.

Purpose of the Study:

• To evaluate the prognostic value of the corrected JT interval (JTc) compared to the QTc.
• To assess the association of JTc and QTc with incident coronary heart disease (CHD) events in individuals with normal and wide QRS duration.
• To determine if JTc offers improved prediction of CHD events in specific demographic groups.

Main Methods:

• Utilized data from the Atherosсlerosis Risk in Communities Study, including 14,696 CHD-free participants.
• Calculated corrected JT interval (JTc) as QTc minus QRS duration.
• Employed logistic regression analysis, adjusting for multiple cardiovascular risk factors, to compare prognostic associations of JTc and QTc.

Main Results:

• In individuals with normal QRS duration, both QTc and JTc were nonpredictive in men but significant in women for future coronary events.
• Among men with wide QRS duration (≥120 ms), JTc demonstrated a significant prognostic advantage over QTc for predicting CHD events.
• In women with wide QRS duration, the analysis was limited by a small number of events (11), precluding definitive conclusions.

Conclusions:

• The corrected JT interval (JTc) is a significant independent predictor of incident CHD events in men with wide QRS complex.
• JTc provides a simple yet powerful tool for risk stratification in specific male populations with conduction abnormalities.
• Further research may be warranted to clarify the prognostic role of JTc in women with wide QRS duration.