Prosthetic heart

The Prosthetic heart is a heart replacement with 80% efficiency. It affects Blood pumping and several dependent stats - due to its below-normal part efficiency it negatively affects healthy pawns but may benefit injured or unhealthy ones. 
== Acquisition ==
== Summary ==
Prosthetic hearts have an 80% part efficiency, or a reduction compared to a healthy organic heart. This results in loss to Blood Pumping. As a positive, installing a prosthetic heart will instantly cure any artery blockages, and prevent heart attacks from any source, including drugs.
The reduction to Blood Pumping lowers move speed by a total and Consciousness by (which also reduces Manipulation, Talking, and Eating). Additionally, it subtracts to Rest Rate Multiplier, so pawns require 6% more rest.
A prosthetic heart results in a 20.3% reduction in an otherwise healthy pawn's market value. Installing a prosthetic heart in a patient with a healthy natural heart will result in the organic heart being kept for later use. Normal organ harvesting penalties do not apply. However, installing one on a guest with a healthy heart causes a -80 goodwill penalty with an allied/neutral faction for an "unnecessary surgery".
=== Installation ===
Installing the part requires of work, 2x medicine of herbal quality or better, and a Medical skill of 4.
Removing the part requires of work, 1x medicine of herbal quality or better, and has no Medical skill requirements.
If the operation fails, the part will be destroyed. If the installation surgery fails, there is also a 25% chance that the patient dies. Thus, as the maximum success chance of any surgery is capped at 98%, there is always at least a 0.5% chance of death per attempt.
== Analysis ==
Prosthetic hearts can be important tools to prevent heart attack deaths in the early game, should an otherwise valuable colonist be prone to them. Its small but significant stat penalties mean that, ideally, natural hearts or bionic hearts should be used instead. Bionic hearts in particular have the same disease immunities, but improve rather than lower stats.
There are also concerns installing a prosthetic heart. Unlike the bionic heart, and like the biological heart, there is a 25% chance of instant death in the event of failed installation. This makes it significantly riskier to install. However, it only requires a medical skill of 4 to attempt compared to the organic heart's 8 and the bionic's 5.
An artificial heart could be used to make the use of wake-up safer in the long term, which could otherwise cause heart attacks. However, wake-up isn't free to make, and you'll lose productivity outside of drug use. This option should be weighed against a circadian half-cycler, which is a one time cost with a flat Consciousness penalty.
On the plus side, prosthetic hearts provide a fairly cheap method of harvesting an ordinary heart. This way, you can get an organic heart without killing a prisoner, or obtain both a heart and a liver; just remember to harvest the liver last, as organs can't be retrieved from a corpse.
While it does provide a buff to pawns with the Body modder trait, its negative effects on healthy pawns (and unavoidable chance of death) means it should be passed over for other, less detrimental prostheses.
===Profit===
A prosthetic heart is worth , while an organic heart is worth . You can then extract a liver for (the same as a heart), which is as fatal as taking the heart without a prosthetic replacement, or let the prisoner live for other purposes.
Keep in mind that there's a natural x0.6 penalty for selling and x1.4 penalty for buying. Profit of a prosthetic heart also depends on your trader's Trade Price Improvement (TPI) and the Trade price disadvantage setting (impacted by difficulty). 
At 0% TPI (no social skill):
* If you buy a prosthetic heart and sell an organic heart, you would get a profit of (in Strive to Survive).
* If you buy 4 components, mine steel, and sell an organic heart, you would get a profit of (in Strive to Survive, assuming you would've sold steel otherwise).
* In Losing is Fun, this drops to profit when buying a full prosthetic heart, and if you buy components.
At 15% TPI (10 social skill, healthy):
* If you buy a prosthetic heart and sell an organic heart, you would get a profit of (in Strive to Survive).
* If you buy 4 components, mine steel, and sell an organic heart, you would get a profit of (in Strive to Survive).
* In Losing is Fun, this drops to profit when buying a full prosthetic heart, and if you buy components.
This does not include the cost of medicine.
== Version history ==
* 0.19.2009 - Added.
Category:Medical Item Category:Body Part Category:Artificial Body Part