The renin-angiotensin agents are very important in both chronic
heart failure and in acute management of high blood pressure.
We know that these agents reduce morbidity and mortality
in heart failure.
They reduce aldosterone secretion and water retention,
and they also reduce total peripheral resistance or
vascular resistance through its antihypertensive effects.
I've listed here all of the ACE inhibitors.
And here are all of the ARBs.
Now, the angiotensin receptor blockers have been in studies
shown to be "non-inferior" to ACE inhibitors.
You'll generally find on the wards that cardiologists favor
ACE inhibitors, and the ARBs are favored by everyone else.
I don't think there is really a right answer
in ACEi versus ARB.
The direct renin inhibitors are a relatively new class
that I discussed in my hypertension lecture,
we don't have a lot of great information
on heart failure at this time.
Now, it's still maybe useful and beneficial in heart failure.
But at this point in time, in 2016, it's not routinely used.
Let's move on to the beta blockers. Remember that in heart failure,
we only use beta blockers once the patient has been stabilized.
Beta blockers may actually be harmful in acute heart failure
because it may suppress cardiac function.
Beta blockers work by two major ways. First of all,
they reduce heart rate and increases stroke volume.
That's because when you reduce heart rate, the heart has
more time to fill, and as it has more time to fill,
each stroke will become more efficient and powerful.
It also reduces overall mortality
and progression of chronic heart failure.
Carvedilol is the favourite beta blocker in heart failure.
Major studies have shown reduction of morbidity and mortality.
Carvedilol has all alpha, beta, and beta 2 effects, so it's a
very effective agent, and it's very well tolerated in heart failure.
Nebivolol is a newer beta blocker that is just come recently to the
United States and Canada and has been in Europe for several years.
It has actions on nitric oxide. At this point in time,
it's relatively investigational in the US and Canada,
but there is a lot of experience in Europe
which shows that it does quite well.