PCP-Cardio Consult: Using Beta-Blockers in Hypertension
Henry Black, MD: Hi. I am Dr. Henry Black, Clinical Professor of Internal Medicine at the New York University School of Medicine, a member of the Center for the Prevention of Cardiovascular Disease at that institution, and immediate past President of the American Society of Hypertension.

I am here with my friend and colleague Bob Morrow. Bob, introduce yourself, please?

Robert Morrow, MD: I am Bob Morrow. I am a family physician in the Bronx. I am also Associate Professor of Family and Social Medicine and Associate Director of Interventional Continuing Education at the Center for Continuing Medical Education at the Albert Einstein College of Medicine.

Dr. Black: I understand that you have some questions about the drugs we use for high blood pressure. What do you think is the most important hypertension agent right now?

Dr. Morrow: Over the years that I have been in practice since I got my license 35 years ago, the medications for hypertension have changed frequently, with different indications than those for which they were introduced.

One thing I encounter a great deal is, what do we do about beta-blockers? Clearly, the cardiologists are very invested in beta-blockers for congestive heart failure and prevention of acute ischemic events in the heart. We continue to think that we should be using a beta-blocker, but should we be using a different drug? Should patients who seem to need a calcium channel blocker be taken off their beta-blocker to avoid problems? Where do we go with this? I am frequently puzzled by this.

Dr. Black: It is an excellent question. Let me give you some historical perspective, because I have been doing this even longer than you have. Beta-blockers were first developed in the 1960s with practolol, which turned out to have fibrotic toxicity, so it was never made. Propranolol was introduced in 1967, mostly in Europe, and here at a very low dose for arrhythmia control. It was not intended for hypertension (that wasn't introduced until 1975 or 1976) even though we used it for hypertension. Propranolol came along with the idea that it was side-effect-free compared with what we had been using -- drugs like methyldopa, reserpine, or guanethidine, which patients didn't tolerate very well.

Over the years, many new beta-blockers were introduced that had some pharmacologic differences. Whether they were beta-1 specific or beta-1 and beta-2 blockers, and whether they had vasodilating actions or alpha-blocking actions, from 1984 on, the Joint National Committee (JNC) considered beta-blockers to be an option for first-line therapy.

That changed recently, for a couple of reasons. One reason was a classic set of papers from Sweden (interestingly enough, because Sweden was the country that was most interested in beta-blockers and used what we consider mega-doses now). Lars Lindholm and colleagues published a couple of analyses: first an analysis of atenolol, and then an analysis of beta-blockers in general that suggested that when used for hypertension, beta-blockers were barely better than placebo and in some cases were worse. JNC 7, the extant guideline in the United States, still considered beta-blockers as the first-line choice. The European guidelines of 2007 and 2010 still designated beta-blockers as a first-line choice. The British thought they shouldn't be a first-line choice. If anything, they thought beta-blockers should be a fourth-line choice. The main confusion -- and cardiologists contributed to it -- was in failing to understand the difference between a "compelling indication" and what should be used as first-line therapy for elevated blood pressure.

A "compelling indication" in JNC 6 (where we first coined that term) meant that if a patient had this condition (angina, heart failure, or arrhythmias), a drug should be prescribed that was shown to be effective for that condition. Those came from trials like the SAVE trial or others which were not hypertension studies, but which looked at other indications for use of antihypertensive drugs. For a compelling indication like heart failure, angina, arrhythmias, or myocardial infarction, there is no question that beta-blockers should be part of the regimen. But beta-blockers are not indicated as initial therapy for hypertension, and that is an important distinction.

Dr. Morrow: We are hearing a lot of talk about sympathetic nervous system activation and lability of blood pressure as a problem for stroke. I have seen a lot of back-and-forth about this, but it would seem more intuitive to use something that blocks sympathetic nerve activity directly in prevention of stroke.

Dr. Black: When you look at stroke as an outcome, beta-blockers are actually worse. In fact, that was the main finding of Lars Lindholm's research.