Beta blocker vs ARNI? (new, learning!)

We'd all be left guessing as you are. This question needs answering, even if just to put you at ease, but nobody here can answer it.

Hello Lizzy

I am not sure what your actual diagnosis is but mine is dilated cardiomyopathy with LBBB resulting in stage 4 heart failure.
I have a cardiac resynchronization device (CRT) with a defibrillator. It is a 3-lead unit that is primarily used in patients who have heart failure. The device has raised my ejection fraction from 19% (at the time of surgery) to 56%. 50% to 70% is considered the normal range.
My quality of life is excellent and I have very few restrictions.
I take all the medications you list (except for B12 shots and metoprolol), plus a few more. I take the following:
Spironolactone 25 mg (diuretic)
Carvedilol 3.125 mg. (beta blocker)
Entresto 49mg./51mg. (ARNI)
Eltroxin 0.05 mg. (thyroid)
Ezetimibe 10 mg (cholesterol)
Rosuvastatin 20 mg (cholesterol)
Jardiance 25 mg (diabetes, type 2 and for HF)
Metformin 500 mg. (diabetes)
Ozempic 1 mg (diabetes)

With Entresto, my b.p. is very uniform at 101/76. And I have had no problems with taking a beta blocker in conjunction with Metformin or Eltroxin.
Your question as to why he chose one over the other may have to do with how he sees your heart condition at this time. I was on a beta blocker for 18 months before Entresto was added to my file. It was added when my EF rate dropped to under 35%. But I am still on it.
Each drug works in somewhat different ways.
Beta blockers work by blocking the effects of adrenaline (epinephrine) and noradrenaline (norepinephrine) on the heart and blood vessels, preventing them from binding to beta-adrenergic receptors, which slows the heart rate, reduces the force of contraction, and relaxes blood vessels, thereby lowering blood pressure and reducing the heart's workload. They interfere with the "fight or flight" response, making the heart beat more slowly and with less force, decreasing the heart's oxygen demand, and are used for conditions like high blood pressure, angina, and heart failure. Metoprolol itself is a selective beta-1 (β1) adrenergic receptor blocker (a type of beta-blocker) that primarily works by preventing the action of the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline) in the heart.
Entresto (sacubitril/valsartan) works by combining two drugs to help the heart pump better in heart failure: sacubitril inhibits the enzyme neprilysin, increasing beneficial peptides that relax blood vessels and remove salt/water; while valsartan blocks angiotensin II, preventing blood vessel constriction and fluid retention, reducing strain on the heart. This dual action enhances protective mechanisms and blocks harmful ones, improving heart function and lowering risks. It doesn't slow your heart rate, though like the beta blocker does.

Both help reduce the work your heart has to do, but in different ways. Now, Jardiance is also considered an important drug in the treatment of heart failure because of the way it works.

For me, it is essential to be learn as much as I can about my diagnosis, the various treatment options and how they work. Not for the purpose of challenging my physician but, instead, so I can be a participant in my own care. Between medications and cardiac devices, heart failure is a very treatable condition.

All the best.

@cottagecountry
Thank you so much for all of this--so helpful. You've encouraged me to keep learning and also with your example. Hearing you say all of this and that your quality of life is "excellent" really encouraged me.
I have only had a few ECGs and the Echocardiagram--showing regurgitation in 3 valves, and IRBBB, and a "weak heart" at 45% EF. There's more detail of course, but I'll know more after my Angiogram. Modstly I have a very strong family history and my dad died at 58 of CHF. Thanks again for sharing your story and wisdom.