Circadian rhythm and sudden death in heart failure: results from Prospective Randomized Amlodipine Survival Trial

Area of Science:

• Cardiology
• Clinical Trials
• Public Health

Background:

• Sudden death is a significant concern in cardiovascular disease.
• A circadian pattern with an early morning peak is typically observed, attributed to sympathetic nervous system surges.
• In advanced heart failure, chronic sympathetic activation may alter this pattern.

Purpose of the Study:

• To investigate the timing of sudden death events in patients with advanced heart failure.
• To determine if the circadian pattern of sudden death differs in this population compared to the general cardiovascular disease population.
• To explore potential underlying mechanisms influencing the timing of sudden death.

Main Methods:

• Analysis of data from the Prospective Randomized Amlodipine Survival Trial (PRAISE).
• Sudden deaths were categorized by time of occurrence (4-h and 1-h blocks) to assess distribution uniformity.
• Stratified analyses were performed for ischemic and nonischemic conditions, and by treatment groups (amlodipine vs. placebo) and background medications (aspirin, warfarin).

Main Results:

• Sudden deaths in the overall cohort exhibited a nonuniform distribution with a peak in the afternoon (PM), not the early morning (AM).
• The ischemic subgroup also showed a PM peak, while the nonischemic subgroup displayed a uniform distribution of events.
• Neither amlodipine treatment nor the use of aspirin or warfarin influenced the timing distribution of sudden deaths.

Conclusions:

• Sudden death in advanced heart failure patients does not exhibit the typical AM peak, indicating that circadian sympathetic activation is not the primary driver.
• The observed PM peak suggests a more complex etiology for sudden death in this patient group.
• Anti-ischemic and antithrombotic medications did not impact the timing patterns of sudden death events.