[Enoximone and ventricular arrhythmia in chronic heart failure]

Area of Science:

• Cardiology
• Pharmacology
• Heart Failure Research

Background:

• Potentially malignant ventricular arrhythmias are common in chronic heart failure (CHF).
• Phosphodiesterase inhibitors (PDE-inhibitors) can increase cytosolic calcium, potentially leading to proarrhythmia, which may be difficult to detect.
• Predicting arrhythmia aggravation in CHF patients is challenging.

Purpose of the Study:

• To evaluate the long-term effects of enoximone therapy on ventricular arrhythmias in patients with advanced chronic heart failure.
• To compare the effects of enoximone and captopril on exercise capacity and arrhythmia profiles in CHF patients.

Main Methods:

• Retrospective analysis of 24-h Holter ECG in 31 CHF patients (NYHA classes III-IV) on long-term enoximone.
• Analysis of 24-h Holter recordings from a randomized trial comparing enoximone and captopril in 20 CHF patients (NYHA class II).

Main Results:

• In the retrospective analysis, most patients on enoximone showed stable or decreased ventricular arrhythmias; a significant increase was seen in 10%.
• In the randomized trial, enoximone reduced exercise capacity compared to captopril, but arrhythmia profiles were similar between groups.
• Overall, 12% of patients in the European Enoximone Data Bank experienced proarrhythmia.

Conclusions:

• Long-term enoximone therapy is generally not associated with a significant increase in ventricular arrhythmias in most advanced CHF patients.
• Despite this, a proarrhythmia risk exists, and individual patient monitoring is crucial due to unpredictable incidence.
• Enoximone therapy may negatively impact exercise capacity in CHF patients compared to ACE inhibitors like captopril.