“What About Beta Blockers After Mitral Valve Repair Surgery?” Asks John
By Adam Pick on June 3, 2014
As a follow-up to our recent discussion about Metoprolol, I received this question from John about beta blockers and mitral valve repair surgery. In his email, John writes, “Is there any convincing evidence for using beta blockers following mitral valve surgery? What are the advantages? Or, is this just protocol? Thanks! John”
To provide Jim an expert opinion, I contacted Dr. Federico Milla of the Marcus Heart Valve Center at Piedmont Heart Institute in Atlanta, Georgia. As you might recall, Doctor Milla is a mitral valve repair specialist who I saw perform several MVRs in the Dominican Republic last year.
Here is Dr. Milla’s response to John. First, he addressed medical research about beta blockers and mitral valve surgery:
In my search I wasn’t able to identify a study specifically looking at the use of beta blockers (BB) following mitral valve surgery. There are numerous studies demonstrating the beneficial effects of beta blockers after open heart surgery that include isolated coronary bypass grafting (CABG) or mixed valve surgery patients, however, none specifically looking at mitral valve surgery. Some of the studies I encountered demonstrate a reduction in the incidence of atrial fibrillation (AF), and I found a few studies looking at the use of BB after aortic valve replacement showing improved cardiac performance and even long-term survival benefits in patients receiving BB.
Then, Dr. Milla addressed why beta blockers are used after cardiac surgery:
Beta-blockers in general blunt the catecholamine or adrenaline response to the stress of surgery. These drugs will reduce the heart rate and blood pressure and may reduce the incidence of AF, as well as help control the heart rate if postoperative AF develops. In fact, hospitals throughout the country that perform heart surgery are graded on certain quality measures, one of them being the use of beta-blocker in patients being discharged from the hospital after heart surgery.
Next, Dr. Milla identified research about the use of beta blockers for patients who did not undergo surgery:
I was able to find an interesting study on the use of beta blockers in patients with chronic degenerative (Primary) mitral valve regurgitation who have NOT undergone surgery. In this randomized controlled trial, patients who did not have symptoms and had chronic severe MR were randomly assigned to a BB instead of placebo. Patients receiving the BB’s were found to have improvement in ejection fraction (the overall strength of the heart) over the two year follow-up. The theory being that patient with MR have increased sympathetic activity causing an increased release of adrenaline, which over time may lead to heart muscle injury.
Dr. Milla concluded his discussion with several interesting ideas about beta blockers and their impact on cardiac function:
Extrapolating from this information, a good percentage of patients undergoing mitral surgery will have changes in their heart structure and function, which may become an indication for surgery. BB may delay these changes, in turn, delaying the indications for surgery. In addition, If we see beneficial effects of BB on patients before mitral surgery, perhaps they may also have some benefits after surgery? We also know that patients with mitral disease are vulnerable to AF both before and after surgery, and taking BB may reduce AF or perhaps slow the rate response to AF.
Many thanks to John for his question and a special thanks to Dr. Federico Milla for sharing his clinical experience and research with our patient community.
Keep on tickin!