Differing effects of beta-blockers on long-term clinical outcomes following percutaneous coronary intervention between patients with mid-range and reduced left ventricular ejection fraction

Beta Blockers can mask not only Hypoglycemia, but also Hypotension

Background:

Beta-adrenergic (β-AR) receptor blockers (BBs) are an essential class of drugs as they have numerous indications. On the other hand, they have numerous unwanted effects which decrease the compliance, adherence, and persistence of this very useful group of drugs.

Objective:

The paper aims to analyze the possibility that an unnoticed side effect may contribute to a less favorable pharmacologic profile of BBs, e.g., a diminished reaction to a sudden fall in BP.

Methods:

We searched two medical databases for abstracts and citations (Medline and SCOPUS). Moreover, we searched the internet for drug prescription leaflets (of the individual BBs).

Results:

Whichever cause of stress is considered, the somatic manifestations of stress will be (partially) masked if a patient takes BB. Stress–induced hypercatecholaminemia acts on β-AR of cardiomyocytes; it increases heart rate and contractility, effects suppressed by BBs. The answers of the organism to hypoglycemia and hypotension share the main mechanisms such as sympathetic nervous system activation and hypercatecholaminemia. Thus, there is a striking analogy: BBs can cover up symptoms of both hypoglycemia (which is widely known) and of hypotension (which is not recognized). It is widely known that BBs can cause hypotension. However, they can also complicate recovery by spoiling the defense mechanisms in hypotension as they interfere with the crucial compensatory reflex to increase blood pressure in hypotension.

Conclusion:

Beta blockers can cause hypotension, mask it, and make recovery more difficult. This is clinically important and deserves to be more investigated and probably to be stated as a warning.

Heart Failure With Mid-range Ejection Fraction: A Distinctive Subtype or a Transitional Stage?

Heart failure with mid-range ejection fraction (HFmrEF) was first proposed by Lam and Solomon in 2014, and was listed as a new subtype of heart failure (HF) in 2016 European Society of Cardiology guidelines. Since then, HFmrEF has attracted an increasing amount of attention, and the number of related studies on this topic has grown rapidly. The diagnostic criteria on the basis of left ventricular ejection fraction (LVEF) are straightforward; however, LVEF is not a static parameter, and it changes dynamically during the course of HF. Thus, HFmrEF may not be an independent disease with a uniform pathophysiological process, but rather a collection of patients with different characteristics. HFmrEF is often associated with various cardiovascular and non-cardiovascular diseases. Thus, the pathophysiological mechanisms of HFmrEF are particularly complex, and its clinical phenotypes are diverse. The complexity and heterogeneity of HFmrEF may be one reason for inconsistent results between clinical studies. In fact, whether HFmrEF is a distinctive subtype or a transitional stage between HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) is controversial. In this review, we discuss the clinical characteristics, treatment and prognosis of patients with HFmrEF, as well as the differences among HFmrEF, HFrEF, and HFpEF.