Does every heart patient need a beta blocker for life? See what a new study says

Researchers used the Swedish national register for coronary heart disease to examine the medical records of people who had a heart attack between 2005 and 2016 and required hospital treatment. The study included records from 43,618 adults, with an average age of 64. About one-fourth were women. None had heart failure or left ventricular systolic dysfunction. Of the participants, 34,253 (78 per cent) were receiving beta-blockers and 9,365 (22 per cent) weren’t receiving beta-blockers one year after hospitalisation for a heart attack. Researchers tracked them for rates of death from any cause, further heart attacks, undergoing re-vascularisation or a procedure to restore blood flow to parts of the heart and heart failure. During the monitoring period, 6,475 (19 per cent) of those on beta-blockers still experienced one of these events. Making allowances for demographics and relevant co-morbid conditions, the researchers reported there was no discernible difference in the rates between the two groups.

The researchers concluded that real-time data showed long-term beta-blocker use was not associated with improved cardiovascular outcomes following a heart attack in people without heart failure or left ventricular systolic dysfunction.

Reacting to the latest study on beta blockers, Dr Balbir Singh, Chairman, Cardiac Sciences, Cardiology, Cardiac, Electrophysiology-Pacemaker, Max Hospitals, says, “The study really doesn’t say anything new as cardiologists world over have been practising discretion when it comes to recommending beta blockers, which let me tell you is magical for heart failure. What the study clarifies is their selective and graded use and clears the air over whether a patient with normal cardiac function needs it. For example, I never recommend beta blockers for hypertension in my patients unless they have tachycardia, or they have a heart rate that’s faster than normal, or more than 100 beats per minute at rest, and need to control it. Beta blockers do not stop a heart attack. But you cannot stop them when the patient has heart failure or left ventricular systolic dysfunction, angina or arrhythmia because they are life-saving in such situations. The study should not give an idea that they are bad drugs. It only confirms what we have been practising for a long time,” says he.

Clearly caution is needed in interpreting the results. As Dr Sunil Dwivedi, senior cardiologist, Manipal Hospitals, Bengaluru, says, “First of all this is just an observational study. For this type of analysis to be applied in clinical practice, we need randomised trials to be more certain about whether beta-blockers should be continued or discontinued beyond one year post myocardial infarction.”

He says that the study proves previous guidelines for treatment protocol. “Our old literature too recommends that beta blockers be given for three years and discontinued except in cases of heart weakness, heart failure, rhythm disturbances and other compelling reasons. Only this study has reduced the duration of weaning off to a year. But the recommendation was similar,” explains Dr Dwivedi.

“What we have observed is that in patients with a history of coronary artery disease (CAD), who have not had either bypass surgery or stenting, beta blockers reduce symptoms of angina and hospitalisations for addressing it. But if they have been re-vascularised (interventions like stents or bypass surgery) or have normal left ventricle function, one may wean such patients off beta blockers gradually, especially if they have significant side effects like fatigue. But beta blockers are non-negotiable as they control arrhythmia and sudden death in heart failure cases. This study says that in patients without any of the complicated risk factors and with normal cardiac function, a long-term continuation of beta-blockers following myocardial infarction may not be of significant benefit. Their benefit is strongest in the early period post-myocardial infarction. The extent of that benefit with long-term use in patients with normal cardiac function is uncertain. In summary, these drugs retain the same value as they did before the study because cardiologists have been taking a conscious call on this anyway,” he adds.