Over the past several years, evidence has been accumulating that shows beta blockers are useful drugs in treating heart failure. A study named the COPERNICUS trial tested the use of beta blockers in 2200 patients. The patients were randomly assigned to either the carvedilol treatment group or the placebo treatment group. Both groups were given ACE inhibitors, diuretics, and digitalis. The results showed a 35% improvement in patients who received the carvedilol and was even greater in patients with very severe heart failure. These patients also did no show any additional side effects than those treated with the placebo. Similar studies were also done using bisoprolol and metoprolol with comparable results. These drugs have been proven to not only improve quality of life, but also improve the chances of survival (Fogoros).
It has also been shown that post myocardial infarction, beta blockers are effective in preventing further MIs or other life threatening cardiac events while calcium-channel blockers have been shown to be ineffective. The explanation for this is still unknown, but the evidence is overwhelming in favor of beta blockers (Singh).
Another study, the Survival and Ventricular Enlargement or SAVE trial, showed that the use of beta blockers resulted in a 30% reduction in cardiac death, a 21% reduction in heart failure, and an 11% reduction in recurrent MIs 42 months post MI (Herrmann).
Studies have also shown that beta blockers are equally effective in men and women (American Heat Association).
A study done by the School of Pharmacy and Institute for Health Policy Studies showed that using beta blockers for all MI survivors, except those with significant contraindications, in the year 2000 and remained on the medication for 20 years would result in 4300 fewer CHD deaths, 3500 MIs prevented, and 45,000 life-years gained compared with current use. If this policy were carried out over 20 years, beta blockers would save $18 million and result in 72,000 fewer CHD deaths, 62,000 MIs prevented, and 447,000 life-years gained (Phillips).
Researchers at the Keck School of Medicine showed that beta blockers were also useful in reducing the risk of death in patients with chronic severe mitral regurgitation or congestive heart failure with normal ejection fraction. The study showed that 65% of these patients on a beta blocker were alive after five years, while only 50% of those not on a beta blocker were alive (Ramdas
Every drug comes with its side effects. When taking a beta blocker, syncope, often referred to as dizziness or lightheadedness, is a side effect that may be strongest when you change position, such as from laying to sitting or standing. Fatigue, headaches, and insomnia can also accompany this class of drugs. Weight gain is more common as your doctor increases the dose of the medication you receive. Dyspnea, bradycardia, and arrhythmias have also been reported with patients using beta blockers. Another side effect that only affects men is impotence. A study in the October 20, 2008 issue of Health Day News showed that the death rate for people given beta blockers before a non-cardiac surgery was ten times higher and the rate of post-operative acute myocardial infarctions was four times higher in the thirty days following an operation than those not getting the drugs. Beta blockers may also cause hyperglycemia; therefore, diabetic patients prescribed beta blockers must be closely monitored. If you are not a diabetic, beta-blockers may also increase your chances of developing diabetes.
After evaluation of the evidence along with consideration of outside sources, we found that many cardiologists agree that caution must be exercised in prescribing beta blockers because it may harm some patients but can clearly benefit others who are at the highest risk of complications post-operatively and with risk factors for cardiovascular disease (Bio-Medicine).
References:
Bullock, C. (2002, March 11). In heart failure, beta-blockers boost survival advantage for women [Online exclusive]. Bio-Medicine. Retrieved from http://news.bio-medicine.org/medicine-news-2/In-heart-failure–beta-blockers-boost-survival-advantage-for-women-8668-1/
Fogoros, R.N. (2003, November 30). Beta blockers in heart failure [Online exclusive]. About.com. Retrieved from http://heartdisease.about.com/cs/heartfailure/a/bbinhf.htm
Herrmann, H.C. (1997, March 11). Beta blockers add benefits after MI [Online exclusive]. Journal Watch. Retrieved from http://cardiology.jwatch.org/cgi/content/full/1997/311/1
Phillips, K.A., Shlipak, M.G., Coxson, P., Heidenreich, P.A., Hunink, M.G.M, Goldman, P.A., Williams, L.W., Weinstein, M.C., & Goldman, L. (2000, December 6). Health and economic benefits of increased beta-blocker use following myocardial infarction. The Journal of the American Medical Association, 284, 2748-2754. Retrieved from http://jama.ama-assn.org/cgi/content/abstract/284/21/2748
Singh, B.N.(1990, September 5). Advantages of beta blockers versus antiarrhythmic agents and calcium antagonists in secondary prevention after myocardial infarction [Web exclusive]. The American journal of cardiology. Retrieved from http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Retrieve&list_uids=1699400&dopt=abstractplus
Varadarajan, P., Appel, D., Joshi, N., Duvvuri, L., & Pai, R.G. (2005, March 8). Beta-blockers may help broader group of patients with heart problems [Online exclusive]. Medical News Today. Retrieved from http://www.medicalnewstoday.com/articles/20875.php
Beta blockers, also known as beta-adrenergic blocking agents, are drugs that block norepinephrine and epinephrine from binding to beta receptors. There are three types of beta receptors and they control several functions based on their location in the body.
There is currently a great deal of controversy regarding the use of beta blockers peri-operatively. According to a recent study by researchers at Boston University, the death rate for people given beta blockers before non-cardiac surgery was ten times higher in the thirty days after an operation for those receiving beta blockers at 2.52% of patients as opposed to those not receiving the drugs at 0.25% of patients. The incidence of an acute myocardial infarction was four times higher at 2.94% of patients for those receiving beta blockers than for those not receiving beta blockers at 0.74% of patients.
