Reader response Draft 1

According to Abbott (n.d.-a), "Surgical heart valves" introduces the "Masters HP 15 mm Mitral Mechanical Heart Valves", a mechanical heart valve suitable for treating new-borns and babies. Abbott's mechanical valve is considered the gold standard and the world's most trusted mechanical heart valve (Abbott, n.d.-b), producing the world’s smallest 15-mm paediatric mechanical valve, approved by the U.S. Food and Drug Administration [FDA] (Office of the Commissioner, 2020). Among its functions, it has rotatable bi-leaflet valves designed for secure implantation in the mitral position (Abbott, n.d.-a) for patients with a diseased, damaged, or malfunctioning mitral heart valve. It also has unique specifications and design features. Firstly, it has a tissue annulus diameter of only 15mm (Abbott, n.d.-a). Secondly, it has a unique design feature, which uses the "Pivot Guard Design" with low thrombogenicity at the forefront of the valve. With several enhanced unique features and functions like the “rotatable bi-leaflet valves” with “Pivot Guard Design”, the Masters HP 15 mm Mitral Mechanical Heart Valve from Abbott is the only 15mm heart valve approved by the FDA that is suitable for treating new-borns and babies suffering from mitral valve problem.

One important function of Abbott’s artificial heart valve is the rotatable bi-leaflet valves, which have proven low thrombogenicity and excellent patient outcomes through clinical trials (Abbott, n.d.-b). The valve leaflets open up to an 85-degree angle in systole(Abbott, n.d.-b); ventricular contraction and ejection on both the left and right heart. The Systole stage of the cardiac cycle “begins when the mitral valve (tricuspid) closes, and concludes with the closure of the aortic valve (pulmonic)”, representing ventricular contraction,  forcing blood into the arteries (Pollock & Makaryus, 2020). The leaflets allow strong, uniform velocities of blood to flow within the hinge recess area, aiding in the washout of blood and preventing blood clots (Abbott, n.d.-b). As compared to caged ball or tilting-disc valves, bileaflet carries a lower risk of blood clots (Artificial Heart Valve, 2023). Therefore, the role of the bileaflet valves is crucially important for the patients to make sure that blood flows smoothly in the arteries. This will potentially reduce the risk of blood clots, a common complication with currently existing prosthetic valves (Fliesler, 2020). 

Features-wise, the tissue annulus diameter of 15 mm is the only mechanical valve that is suitable for newborns and baby patients. Similarly to the aortic and mitral 15 mm valves, both have a geometric orifice area of 1.3 cm2, an overall height open of 8.5 mm and the cuff outer diameter (OD) of 20 mm(Abbott, n.d.-a). The difference between the 15 mm valve is that for mitral, the implant height open is 2.2 mm as compared to aortic with 4.6 mm, as required for 2 different types of surgery with the same 15 mm in tissue annulus diameter valve (Abbott, n.d.-a). Furthermore, the “Pivot Guard Design” helps to shield the pivot mechanism from pannus ingrowth (Abbott, n.d.-b), a growth of abnormal tissue around a prosthetic heart valve, causing the heart valve to be dysfunctional (Ha et al., 2018). This design ensures a consistent 85-degree opening angle of the bi-leaflet valve, promoting minimized leaflet flutter and more laminar flow through the orifice (Abbott, n.d.-b). It is important as it helps to reduce energy losses in the flowing blood by minimizing viscous interactions between the adjacent layers of blood and the wall of the arteries (Klabunde, n.d.). It is also designed with low thrombogenicity at the forefront of the leaflet. The low thrombogenicity will lower the tendency of a material to generate blood clotting, when in contact with blood (Thrombogenicity - an Overview | Sciencedirect Topics, n.d.). With the two features, it is the only mechanical heart valve available that is able to treat new-borns and babies with a pivot guard design which improves the flow of blood through the mechanical heart valve, lowering the chance of blood clotting.

 However, as much as being the smallest mechanical valve, the main disadvantages of mechanical heart valves are the consumption of blood thinner for life, not suitable for women at child-bearing age and not suitable for patients prone to falls. There are also side effects of long-term consumption of blood thinner. According to Marcin (2022), long-term consumption of blood thinner includes the risk of bleeding, bleeding significantly from small cuts, skin rashes and hair loss. Aside from bleeding-related issues, consumption over a period of time might cause nausea and low blood count; causing fatigue, weakness, dizziness and shortness of breath (7 Things to Know about Taking Blood Thinners Safely, n.d.) which possibly affects patients’ daily lives.

In conclusion, different types of artificial heart valves; mechanical, bioprosthetic and tissue valves, have their pros and cons. My main target is to focus on the treatment of mitral heart problems for new-borns and babies. The increase of cases of children of younger age left untreated or delayed in treatment, causes more loss of lives. With the Masters HP 15 mm Mitral Mechanical Heart Valves from Abbott, it will potentially help and treat new-borns and babies being the only 15 mm heart valves that are meant to fit into their arteries.

Reference:

• 7 things to know about taking blood thinners safely. (n.d.). Mercy. https://www.mercy.net/service/atrial-fibrillation/taking-blood-thinners-safely/#:~:text=Aside%20from%20bleeding%2Drelated%20issues

• Abbott. (n.d.-a). Masters mitral and aortic mechanical valves | Abbott. Www.cardiovascular.abbott. 

https://www.cardiovascular.abbott/us/en/hcp/products/structural-heart/surgical-valve-solutions/masters-mechanical-valves.html

• Abbott. (n.d.-b). Mechanical Heart Valves | Regent Valve and Master Series. Www.structuralheart.abbott. https://www.structuralheart.abbott/products/mechanical-heart-valve/regent-valve-masters-series-mechanical-heart-valve

• Artificial heart valve. (2023, September 10). Wikipedia. https://en.wikipedia.org/wiki/Artificial_heart_valve#:~:text=Bileaflet%20valves

Fliesler, N. (2020, February 20). Breakthrough bileaflet heart valve could be the only one a child needs. Boston Children’s Answers. https://answers.childrenshospital.org/bileaflet-heart-valve/#:~:text=Potential%20for%20fewer%20blood%20clots

• Ha, H., Koo, H. J., Huh, H. K., Kim, G. B., Kweon, J., Kim, N., Kim, Y.-H., Kang, J.-W., Lim, T.-H., Song, J.-K., Lee, S. J., & Yang, D. H. (2018). Effect of pannus formation on the prosthetic heart valve: In vitro demonstration using particle image velocimetry. PLOS ONE, 13(6), e0199792. https://doi.org/10.1371/journal.pone.0199792

• Klabunde, R. E. (n.d.). CV physiology | laminar flow. Cvphysiology.com. https://cvphysiology.com/hemodynamics/h006#:~:text=The%20orderly%20movement%20of%20adjacent

• Marcin, A. (2022, December 2). What to know about long-term blood thinner use. Healthline. https://www.healthline.com/health/living-with-atrial-fibrillation/advancements/long-term-blood-thinner-use#:~:text=Blood%20thinners%20may%20cause%20side%20effects%20like%20nausea%2C%20bleeding%2C%20skin

• Office of the Commissioner. (2020, March 24). FDA expands approval of replacement heart valve, smallest mechanical valve size approved in the world. FDA. https://www.fda.gov/news-events/press-announcements/fda-expands-approval-replacement-heart-valve-smallest-mechanical-valve-size-approved-world

• Pollock, J. D., & Makaryus, A. N. (2020). Physiology, Cardiac Cycle. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK459327/#:~:text=Cardiac%20cycle%20events%20can%20be

• Thrombogenicity - an overview | sciencedirect topics. (n.d.). Www.sciencedirect.com. https://www.sciencedirect.com/topics/medicine-and-dentistry/thrombogenicity#:~:text=Thrombogenicity%20can%20be%20defined%20as