Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mayo Clinic study sets threshold for valve repair surgery

03.03.2005


Surgery gives normal life expectancy to patients with severe mitral regurgitation; death risk for medically treated patients is five times greater



"We know from previous studies that patients with symptomatic mitral regurgitation are at increased risk of death, but for those without symptoms the picture has been murkier," says Maurice Enriquez-Sarano, M.D., the Mayo Clinic cardiologist who led the study. "In this study we followed a large population of asymptomatic patients prospectively to identify keys to improved long-term outcomes, and to determine when patients should consider surgery."

The mitral valve separates the left upper chamber of the heart (atrium) from the left lower chamber (ventricle). In mitral regurgitation this valve does not close properly, which causes some blood to backwash into the heart from the left ventricle instead of being pumped out to the rest of the body. The left atrium typically enlarges due to this pressure, and as a result of this compensation the patient may not experience symptoms initially. As the disease progresses, symptoms may include fatigue, exhaustion, light-headedness, shortness of breath and heart palpitations.


Mitral regurgitation of moderate degree or more is frequent, particularly in the aging population. It is estimated that 2 to 2.7 million Americans are afflicted by this condition and that this number will rise to 3.8 to 4.8 million Americans by 2030.

The Mayo Clinic researchers used Doppler echocardiography – ultrasound images of the heart and its blood flow patterns – to determine which physical characteristics predicted patient outcomes. Age and diabetic status were strongly associated with poorer outcomes. However, the most important finding was that the effective regurgitant orifice area – the cross-sectional size of the jet stream of blood backwashing into the atrium – was the strongest determinant of outcome.

Patients with a regurgitant orifice larger than 40 mm2 who were treated only with medication were more than five times more likely to die than those with the same severity of regurgitation who underwent valve repair surgery.

Dr. Sarano says the quantitative data from this study, combined with advances in surgical techniques and improved surgical results, help define at what severity of regurgitation patients should strongly consider valve surgery. "The mortality for valve surgery is very low, but it is not zero," Dr. Sarano explains. "Previously, with patients who were asymptomatic, we had no well-defined quantitative method to determine when the risk of continuing to rely on medication alone exceeded the risk of surgery. Now we have a threshold established through this large study, where continuing medical management carries a much higher risk and surgery can restore normal life expectancy."

Dr. Sarano says the study has important implications for patients and the physicians who treat them. "We examined dozens of variables in this study, and the one physical measurement that strongly predicted survival was regurgitant orifice," he explains. "Patients should be aware that severe mitral regurgitation increases their risk of dying even if they don’t have symptoms, and that now we have a measurement technique to determine how severe is too severe and who benefits the most from early intervention."

Other authors of the paper include Jean-Francois Avierinos, M.D.; David Missika-Zeithoun, M.D.; Delphine Detain, M.D.; Maryann Capps; Vuyisile Nkomo, M.D.; Christopher Scott; Hartzell Schaff, M.D. and A. Jamil Tajik, M.D., all of Mayo Clinic.

Lee Aase | EurekAlert!
Further information:
http://www.mayoclinic.com

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>