Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clonidine reduces post-surgical risk of cardiovascular death in non-cardiac surgery

27.07.2004


Patients with or at risk for heart disease who take the anti-hypertensive drug clonidine before non-cardiac surgery can significantly reduce the risk of complications and death due to inadequate blood flow to the heart, according to a study by UCSF researchers at the San Francisco Veterans Affairs Medical Center.



The findings add a second drug to the list of inexpensive preventive measures available to these patients before non-cardiac surgery. In 1998 the same UCSF/SFVAMC researchers identified the beta blocker atenolol as an effective preventive measure for this patient group. The clonidine research is reported in the August 2004 issue of the journal Anesthesiology.

"In the earlier study we found an inexpensive way to reduce the incidence of death due to surgery. Now we have found another drug to do the same thing," said lead researcher Arthur Wallace, MD, PhD, UCSF associate professor of anesthesia and perioperative care and staff anesthesiologist at the SFVAMC.


The clonidine study focused on 190 male patients scheduled to undergo non-cardiac surgery who had been diagnosed with coronary artery disease or had at least two of five risk factors for cardiac disease: age 60 or older, hypertension, smoking within a year, cholesterol of 240 or greater or diabetes. Scheduled surgeries included orthopedic, head and neck, abdominal and others.

Of the patients, 125 received a .2 mg oral tablet of clonidine the night before surgery, a transdermal patch of clonidine the night before surgery and a .2 mg tablet one hour before surgery. A control group of 65 received placebos. After follow-ups of three days, 14 days, 30 days and two years, the clonidine group showed a death rate of 1 percent compared to 6 percent for the placebo group. After two years, the death rate of the clonidine group was 15 percent compared to 29 percent for the placebo group.

Patients were monitored for episodes of blocked blood flow using Holter electrocardiogram recorders--before, on the day of, and up to seven days after surgery. They also received electrocardiograms to measure the heartbeat every day for the first seven days after surgery and whenever necessary due to shortness of breath, chest pain or loss of consciousness. Blood pressure was recorded continuously from one hour before surgery to one hour following surgery, and blood samples were analyzed for presence of heart enzymes and clonidine concentrations.

Researchers found that patients who had received clonidine showed no evidence of myocardial ischemiac events (inadequate blood flow to the heart) before surgery compared to 5 percent for those who had received placebos.

On the day of surgery and up to three days after surgery only 14 percent of clonidine patients experienced such events, compared to 31 percent for placebo patients. After 30 days, one (.8 percent) of the clonidine patients had died compared to four (6.2 percent) of placebo patients. In a two-year follow up, 19 (15 percent) of the clonidine group had died compared to 19 (29 percent) of the placebo group.

"For these patients, myocardial ischemia is associated with a nine-fold increase in cardiac complications before hospital discharge and a two-fold greater two-year risk of death after surgery. Drug therapy to prevent blocked arteries prevents the start of a chain of events leading to heart attack and death," said Wallace.

Researchers conclude that patients with or at risk for coronary artery disease who undergo non-cardiac surgery should be considered for pre-surgery treatment with either atenolol, which is a beta blocker, or clonidine, which is an alpha2-agonist, as these substances have been shown to prevent symptoms of cardiac disease and death. A beta blocker blocks stress hormones produced in the brain from stimulating the heart. An alpha2-agonist decreases the release of stress hormones produced in the brain.

Six million Americans with or at risk for cardiac disease undergo non-cardiac surgery each year. "The current study clearly demonstrates a significant difference in 30-day and two-year mortality using a prophylactic and anti-ischemic therapy," the researchers wrote.

While the study does not indicate which treatment is superior, protocols for using both drugs are included in joint surgery guidelines of the American Heart Association and the American College of Cardiology.

The study was funded by the American Heart Association, Veterans Administration Merit Review Funding, Ischemia Research and Education Foundation and the Northern California Institute for Research and Education (NCIRE), a federal nonprofit foundation affiliated with the SFVAMC.

Study co-investigators are Daniel Galindez, MD, and Ali Salahieh, BS, research associates, Anesthesiology Service, SFVAMC; and Elizabeth L. Layug, MD, research associate; Eleanor A. Lazo, MD, research fellow; Kathy A. Haratonik, BA, research technician; and Dennis M. Boisvert, MS, and David Kardatzke, PhD, statisticians, all of the Ischemia Research and Education Foundation.

Joan Aragone | EurekAlert!
Further information:
http://www.ucsf.edu

More articles from Health and Medicine:

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Introduction of a novel system for in vitro analyses of zebrafish oligodendrocyte progenitor cells

23.10.2017 | Life Sciences

Did you know how many parts of your car require infrared heat?

23.10.2017 | Automotive Engineering

3rd Symposium on Driving Simulation

23.10.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>