Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study finds digoxin safe despite recent reports

17.04.2013
Evidence lacking that digoxin increases mortality

A study published today in the European Heart Journal found no evidence that digoxin increases mortality in patients with atrial fibrillation (AF), the opposite of results just published by another group in the same journal analyzing the same data.

Older patients with AF also often have heart failure, and digoxin is approved to treat both conditions. AF is the most common kind of cardiac arrhythmia, an electrical malfunction that throws off the heart's rhythm and pumping rate. It may cause no symptoms or cause some patients to faint, but is seldom fatal. Heart failure, a gradual weakening of the heart's pumping strength, contributes to 280,000 U.S. deaths each year.

Both the earlier study that found digoxin increases mortality in AF and the study published today were re-analyses of data first collected as part of a clinical trial called Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) in 2002. The recent study that found digoxin increases mortality used an approach called "time-varying treatment," where patients who continued to receive digoxin over 3.4 years as part of the follow-up to AFFIRM were compared to those who did not.

According to current study, this "time-varying treatment" technique produced misleading results. By analyzing data from sicker patients who required continued digoxin treatment over the long term, it inadvertently introduced bias in its analysis of digoxin-related mortality.

"Digoxin is recommended by major national guidelines for use in heart failure and atrial fibrillation," said Mihai Gheorghiade, M.D., lead author of the study and professor of medicine and of surgery at Northwestern University Feinberg School of Medicine. "It is an inexpensive drug that is generally well tolerated at low doses, and there is no reason to question its usefulness or reassess its safety. We need to remember that although digoxin has been used for over two centuries, it was approved by the FDA in the late 1999s under its strict guidelines for new drug approval based on its safety and efficacy data from multiple randomized clinical trials. So, we are not talking about a new or unsafe drug when we talk about digoxin."

To test the safety of digoxin, the current authors used AFFIRM patient data to assemble a group found to be similar based on 59 characteristics, including age, sex, race, other conditions beside AF (including heart failure) and other medications. Researchers then divided this pool of similar patients into two groups, one that had received digoxin therapy and a second that had not.

The study team found that during the 3.4 years of follow-up, 14 percent of patients receiving digoxin and 13 percent of patients not getting it died. This difference is well within the study's margin of error and, in practical terms, represents no increase in mortality associated with digoxin (hazard ratio, 1.06; 95% confidence interval {CI}, 0.83.37; P=0.640). Among matched patients, digoxin was also not associated with all-cause hospitalization (hazard ratio, 0.96; 95% CI, 0.85.09; P=0.510) or arrhythmias (hazard ratio, 0.90; 95% CI, 0.37.23; P=0.827).

"Heart failure is the only other condition for which digoxin is used, so many of the patients who continued digoxin in the AF clinical trial also had heart failure," said Ali Ahmed, M.D., professor in the divisions of Gerontology, Geriatrics, & Palliative Care and Cardiovascular Disease within the School of Medicine at the University of Alabama at Birmingham (UAB), and the new study's senior author. "You cannot conclude that a drug kills more people without considering whether or not the drug is prescribed for a deadly condition."

The authors conducted the study out of concern that older patients might be deprived of digoxin, which can be helpful in treating AF. They worried that the perception that digoxin increases mortality in AF might gain traction and extend to the treatment of heart failure.

Ahmed recently demonstrated that digoxin could reduce by 34 percent the chances that heart failure patients will be admitted to the hospital within 30 days of first taking it. Preventing frequent admissions is national priority, as the Centers for Medicare and Medicaid Services (CMS) penalized thousands of hospitals in 2012 for above average 30-day readmission rates in patients with pneumonia, heart attack or heart failure.

One in five Medicare recipients is readmitted within 30 days at an annual national cost of $17 billion. Heart failure is the most common culprit. Digoxin is known to reduce acute heart failure symptoms like shortness of breath, which can send people racing back to emergency rooms.

The current debate over the digoxin comes at the end of a decline in use since it failed to lower mortality in an original clinical trial. Research in recent years, however, has shown that digoxin is the only drug in its class (positive inotropes) that does not increase mortality at the traditional dose, and that it may block neurohormone systems like beta blockers or ACE inhibitors. This may explain study results suggesting that low-dose digoxin not only reduces the risk of hospitalization, but may also reduce the risk of death.

In a final note, the current study authors said the scientific community has for years been urging sponsors of large clinical trials for more transparency and data sharing. The National Heart, Lung and Blood Institute (NHLBI) has been a leader in this regard, establishing the Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC), which has made available the public-use copy of the AFFIRM data that enabled the study authors to challenge the conclusions of the previous study.

Gheorghiade disclosed consulting relationships with industry, detailed in the journal article.

The original AFFIRM study was supported by the National Heart, Blood and Lung Institute of the National Institutes of Health and Ahmed's work by NHLBI grants (R01-HL085561, R01-HL085561-S and R01-HL097047).

Marla Paul | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>