Heart failure management with β-blockers: can we do better?

The clinical value of β-blockers in patients with stable angina

Stable angina, one manifestation of chronic coronary syndrome (CCS), is characterised by intermittent episodes of insufficient blood supply to the myocardium, provoking symptoms of myocardial ischaemia, particularly chest pain. These attacks usually occur during exercise or stress. Anti-ischaemic drugs are the mainstay of pharmacologic management of CCS with symptoms of angina. β-blockers reduce heart rate and myocardial contractility, thus reducing myocardial oxygen consumption. These drugs have been shown to ameliorate the frequency of anginal attacks and to improve exercise capacity in these patients. Current management guidelines include β-blockers as a first-line management option for most patients with CCS and symptoms of myocardial ischaemia, alongside dihydropyridine calcium channel blockers (CCB). The presence of comorbid angina and heart failure is a strong indication for starting with a β-blocker. β-blockers are also useful in the management of angina symptoms accompanied by a high heart rate, hypertension (with or without a renin-angiotensin-aldosterone-system [RAS] blocker or CCB), or microvascular angina (with a RAS blocker and a statin). A β-blocker is not suitable for a patient with low heart rate (<50 bpm), although use of a β-blocker may be supported by a pacemaker if the β-blocker is strongly indicated) and should be used at a low dose only in patients with low blood pressure.

Sympathetic overactivity, hypertension and cardiovascular disease: state of the art

Cardiovascular disease (CVD) remains the most prevalent cause of premature death worldwide. It had been suspected for decades that increased activity of the sympathetic nervous system (SNS) might play a pathogenetic role in the development and progression of hypertension, heart failure (HF) and CVD. The use of microneurographic techniques to directly assess the SNS has allowed this field to advance considerably in recent years. We now have compelling evidence for a key role of sympathetic overactivity in the pathogenesis and progression of hypertension and associated hypertension-mediated organ damage (such as endothelial dysfunction, arterial stiffness and left ventricular hypertrophy), HF (with or without reduced left ventricular ejection fraction). Sympathetic overactivity also drives increased cardiovascular risk in the settings of obesity, metabolic syndrome, chronic kidney disease and obstructive sleep apnoea, among other conditions. Thus, sympathetic overactivity is an important factor that drives patients through the CVD continuum, from the early appearance of cardiovascular risk factors, to impairments of the structure and function of components of the heart and arteries, to established CVD, and ultimately to a life-threatening cardiovascular event. A deeper understanding of the role of sympathetic overactivity in the pathogenesis of CVD and HF will support the optimization of therapeutic interventions for these conditions.

β-blockers are not all the same: pharmacologic similarities and differences, potential combinations and clinical implications

β-blockers are a heterogeneous class, with individual agents distinguished by selectivity for β1- vs. β2- and α-adrenoceptors, presence or absence of partial agonist activity at one of more β-receptor subtype, presence or absence of additional vasodilatory properties, and lipophilicity, which determines the ease of entry the drug into the central nervous system. Cardioselectivity (β1-adrenoceptor selectivity) helps to reduce the potential for adverse effects mediated by blockade of β2-adrenoceptors outside the myocardium, such as cold extremities, erectile dysfunction, or exacerbation of asthma or chronic obstructive pulmonary disease. According to recently updated guidelines from the European Society of Hypertension, β-blockers are included within the five major drug classes recommended as the basis of antihypertensive treatment strategies. Adding a β-blocker to another agent with a complementary mechanism may provide a rational antihypertensive combination that minimizes the adverse impact of induced sympathetic overactivity for optimal blood pressure-lowering efficacy and clinical outcomes benefit.