Prof. Hana Rosolová: According to recent studies, caution is needed with beta-blockers only in severe cases of asthma and COPD
Beta-blockers (BB) are among the most widely used drug groups in cardiology. While their position is clear in some indications, it is debated in others. Additionally, individual BBs differ in various aspects, which plays an important role in selecting the right treatment for a particular patient. We discussed some current topics related to beta-blockers with the head physician of the Center for Preventive Cardiology of the 2nd Department of Internal Medicine LF UK and FN Plzeň Prof. MUDr. Hana Rosolová, DrSc., FESC.
According to European and Czech guidelines, beta-blockers form one of the 4 pillars of treatment for chronic heart failure (CHF). However, their role is sometimes questioned or labeled controversial in other indications, particularly in the treatment of arterial hypertension (AH). How do you perceive this issue based on your practice?
Beta-blockers are an indispensable part not only of the treatment of chronic heart failure and other cardiovascular diseases (CVD), but also of arterial hypertension. Their impact in reducing morbidity and mortality from CVD is smaller than that of other antihypertensives but statistically significant according to many studies. A hypertensive patient who is still in primary prevention of CVD but with increased sympathetic nervous system activity, hence a higher heart rate (over 75 beats per minute), a tendency to sweat, or show signs of neurasthenia with palpitations or tremors, is a good candidate for a combination of antihypertensives that includes a beta-blocker.
Current European recommendations for the treatment of arterial hypertension specify the suitability of using beta-blockers in this indication for different groups of patients or in various situations. Does this mean a definitive clarification and return to their widespread use in AH therapy?
Current European and our Czech recommendations favor the use of beta-blockers mainly in combination therapy for patients with AH and different forms of ischemic heart disease (IHD) or CHF or significant left ventricular dysfunction. Additionally, they are allowed for pregnant hypertensive women in the 2nd and 3rd trimesters.
Beta-blockers differ from each other in pharmacokinetics, pharmacodynamics, degree of selectivity, method of elimination from the body, and safety profile or side effects. The key criteria in choosing the right BB for cardiology should be cardioselectivity. Even among selective β1-blockers, there are differences. Can we truly individualize treatment for each patient to ensure their good compliance and adherence to BB use, which determines the success of the therapy?
Beta-blockers differ primarily in their cardioselectivity. Non-selective BBs, such as trimepranol or propranolol, act on both β1 and β2 receptors, meaning in the heart and other organs like the bronchi. In contrast, cardioselective ones act mainly on β1 receptors, primarily in the heart. We have already moved away from the 1st generation non-selective BBs in favor of the 2nd and 3rd generations.
What's the difference between the 2nd and 3rd generation BBs?
These classes differ in their effects on the vessel walls. The 3rd generation beta-blockers have a vasodilatory effect and are thus indicated mainly for CHF. The 2nd generation, represented by atenolol, bisoprolol, or metoprolol, is more suitable for treating AH. Another characteristic is lipophilicity or hydrophilicity. The hydrophilic atenolol, which is the least cardioselective of the 2nd generation, is also being phased out due to some of its adverse effects on glucose and lipid metabolism.
How well does it work in practice to combine the cardiological indication of BB usage with the management of non-cardiological diseases that have high prevalence in the population? What are the most common drug interactions and which chronic diseases cause the most issues when BBs are prescribed?
The most discussed non-cardiological diseases in connection with beta-blocker treatment are chronic bronchitis, bronchial asthma, and chronic obstructive pulmonary disease (COPD). However, I dare say this is somewhat of an atavism. Selective beta-blockers should not reduce the efficacy of bronchodilators, let alone cause bronchospasm. I have never seen these effects in my practice, and I worked for 5 years in a pulmonary department where we often used selective BBs for patients with the aforementioned lung diseases and tachycardia or AH or IHD. According to recent studies, caution is only necessary in severe forms of asthma and COPD.
Another topic in connection with beta-blockers is their effects from long-term use in secondary prevention in patients after myocardial infarction (MI) or ischemic stroke (iCMP), as well as in primary prevention in individuals with high CV risk. What are your experiences with these indications?
Long-term, sometimes lifelong use of beta-blockers in secondary prevention of atherosclerotic CV diseases or in individuals with high CV risk is an unresolved issue. The protective effect of BBs was proven in the 1980s only in patients after myocardial infarction with reduced left ventricular ejection fraction. In one of the latest studies on this topic, specifically a Danish study published this year in the American Journal of Cardiology, it was shown that even smaller doses of BBs significantly reduce mortality after an acute MI, especially in the first year. However, we do not yet have data from a prospective long-term placebo-controlled study for lifelong use.
Bisoprolol is among the commonly prescribed beta-blockers. What are its advantages over other BBs?
It is a very cardioselective β1-blocker that is very well tolerated. Another advantage is its 50% elimination through the kidneys and 50% through liver metabolism, which is certainly beneficial for patients with renal impairment or liver diseases.
Is bisoprolol suitable for fixed combination?
Combining it with non-dihydropyridine calcium channel blockers (CCBs), such as verapamil, is not recommended due to the risk of conduction system disorders. On the other hand, combining it with dihydropyridine CCBs like amlodipine or with inhibitors of the renin-angiotensin-aldosterone system (RAASi) is very suitable.
Who specifically benefits from a combination of bisoprolol and amlodipine?
For patients with hypertension and higher sympathetic activity, which are usually younger hypertensives, obese individuals, smokers, and those in the prediabetes stage or already with type 2 diabetes. Other candidates are patients with stable angina pectoris or chronic IHD.
Eva Srbová
editorial staff of proLékaře.cz
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