One: begin your target BB at the start. I don’t know how the culture of starting short acting metoprolol “for titration” came from but it’s not supported by any science, uses a drug that failed in the MDC trial, and may actually be harder to titrate due to on/off effects.
Two: if you use carvedilol, scan the med list for other alpha blockers and d/c them. Carvedilol has alpha blocking effects, so if you d/c the other it’s likely to “buy” more BP, and won’t be noticed. Remember—tamsulosin (used for BPH) is an alpha blocker…
Three: more than any other #GDMTworks, BB are very strongly dependent on reaching target doses for their benefits.
In your discharge summary, always provide a battle plan for how the drug should be titrated including what the target those should be.
Four: all of this is for heart failure with reduced ejection fraction.
The flip-side is that in patients with heart failure and preserved ejection fraction, BB may worsen exercise tolerance, and might actually be discontinued in some.
Day 6 on service at @MGHHeartHealth and we're running on fumes. But Thanksgiving is just around the corner, so all is well.
At the request of Dr. @CoronaryDoc, a thread on appropriate use of natriuretic peptides.
There's a time to measure them. And a time not to.
Just a reminder of NP biology:
NP genes are highly conserved across species. Your ANP is only one amino acid different than the ANP of a rat, for example.
In addition to being conserved across species, the three CV NPs (ANP, BNP, CNP) have structural similarities.
In addition to having a common ring structure responsible for their biologic effect, all three CV NPs (A, B, C) are synthesized as pre-pro-peptides, and are processed by corin/furin to liberate an N-terminal pro-peptide and a biologically active C-terminal fragment.
Day 5 on service at @MGHHeartHealth. No better time than now to think about the favorite drug of @AndrewJSauer...spironolactone.
The story of how the drug was discovered is interesting, and gave a hint as to the fact the drug would eventually become a pillar of HF care.
The first mineralocorticoid synthesized was deoxycorticosterone (DOC). Simultaneously, aldosterone was discovered. Both exerted powerful sodium retention effects. This was in the early 1950s.
Simultaneously, people began to recognize that pts with HF retained salt and water...
Recognizing that Na/water retention in HF resembled that of DOC/aldo treatment, efforts began on the synthesis of ways to block their effects with a family of compounds called 17-spironolactones.
one had potent anti-mineralocorticoid effects, and was dubbed "aldactone".
It's a little known fact that prior to the PH3 PARADIGM trial, a PH2 study in HFrEF was not performed--normally PH2 studies provide target doses for the pivotal outcomes trials.
So how was the dose of sacubitril/valsartan chosen??
The target dose of 97/103 mg twice daily was selected to achieve serum concentrations of valsartan = to those in Val-HeFT and VALIANT while simultaneously achieving 90% neprilysin inhibition in normal individuals.
Thanks to work by @pmyhre in our group, we have some new and interesting data.
A 🧵, read on! 👇
When the #PARADIGM-HF study was published, one of the things immediately noticed was the increase in BNP that occurred after being started on sacubitril/valsartan.
This is because through effect of sacubitril, neprilysin is inhibited. Why might this lead to an increase in BNP?
#Neprilysin is a ubiquitous metalloproteinase that assaults BNP (among other targets including ANP and CNP) and cleaves it in numerous places as shown.
Note that in BNP, there are cleavage sites that involve numerous places where immunoassays for measurement of BNP may bind.
--unexplained mild "LVH"
--PAF that has little explanation
--spinal stenosis
--carpal tunnel
--orthostatic hypotension
--bruising
--lack of EF response to #GDMTworks
--Diuretic sensitivity
--Higher biomarkers "than they should be"
Why are biomarkers higher in amyloid? It has mainly to do with direct myocardial toxicity of the amyloid protein, and NOT congestion/ischemia in most cases.
hs-cTn is almost universally elevated.
Both NPs and hs-cTn are prognostic, regardless of their 'decoupling' from HF/MI.