Survival after withdrawal of dofetilide in patients with congestive heart failure and a short baseline QTc interval; a follow-up on the Diamond-CHF QT substudy.

Abstract

BACKGROUND:

We have previously observed dofetilide to be associated with improved survival when the pre-treatment baseline QTc interval was below 429 ms. In this study we tested the natural extension of this observation-that the same group of patients should have a loss of survival benefit after withdrawal of dofetilide.

METHODS:

Patients with congestive heart failure (CHF) and reduced left ventricular function enrolled in the Diamond-CHF (Danish Investigations of Arrhythmia and Mortality on Dofetilide-CHF) study were eligible for our QT substudy provided they were in sinus rhythm and had a measurable QTc interval from a 12-lead standard ECG taken before randomization to placebo or dofetilide. An extended follow-up was performed from study closure, December 1996 until August 2001.

RESULTS:

Of the 418 patients entering the extended follow-up, 215 (51%) patients died during this 4.5 years of additional observation time. The baseline QTc interval made no prognostic difference to mortality in placebo treated patients. For dofetilide treated patients with a baseline QTc interval <429 ms, increased mortality was observed during the extended follow-up compared to placebo (risk ratio 1.5, 95% confidence interval 1.1-2.8)[corrected].

CONCLUSIONS:

This follow-up study shows significant loss of survival benefit upon withdrawal of dofetilide in patients with CHF and a pre-treatment QTc interval below 429 ms. An independent randomized trial is warranted to validate these results.

• Authors: B Brendorp, C Torp-Pedersen, H Elming, L Køber
• Journal: European heart journal (Eur Heart J) Vol. 24 Issue 3 Pg. 274-9 (Feb 2003) ISSN: 0195-668X [Print] England
• PMID: 12590905 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Arrhythmia Agents
• Phenethylamines
• Sulfonamides
• dofetilide

Topics

• Adult
• Aged
• Anti-Arrhythmia Agents (administration & dosage)
• Double-Blind Method
• Female
• Follow-Up Studies
• Heart Failure (drug therapy, mortality)
• Humans
• Infant, Newborn
• Long QT Syndrome (drug therapy, mortality)
• Male
• Middle Aged
• Phenethylamines (administration & dosage)
• Proportional Hazards Models
• Risk Factors
• Sulfonamides (administration & dosage)
• Survival Analysis
• Treatment Outcome
• Ventricular Dysfunction, Left (drug therapy, mortality)