Elevated Troponin why and how does it relate to renal failure

Troponin is a protein that is involved with the contractility of the both skeletal muscle and cardiac muscle. There are three subtypes (T, I, and C). Both muscle types express troponin C and troponin I & T are generally specific to cardiac muscle. The clinical importance of these proteins is that an increase in laboratory values may suggest acute coronary syndrome or myocardial infarction.

With regard to ESRD and elevated troponin levels the cause is controversial. Some research suggests that the cause is due to cardiac injury and the kidneys are not able to filter the troponin protein. Other research suggests that the kidneys degrade the troponin into smaller fragments and these fragments are picked up by the assays and cause an elevated reading. According to UpToDate the elevated troponin levels are likely caused by a history of chronic myocardial injury or another underlying heart disease. There is no evidence that elevated troponin levels in CKD patients is associated with renal clearance or increased cardiac release.

It is noteworthy to mention that troponin levels are still indicated for the diagnosis of AMI in patients with CKD because troponin levels are superior to other cardiac markers such as CK-MB. The Joint Task Force (European Society of Cardiology, World Heart Federation, American College of Cardiology Foundation) suggests trending the troponin levels instead of using a single value for troponin. For CKD patients with a troponin level above 99 percentile and have an increase in troponin of greater than 20% change in trending levels may have a possible diagnosis of AMI.

 

• https://www.uptodate.com/contents/serum-cardiac-biomarkers-in-patients-with-renal-failure?sectionName=Troponins&search=elevated%20troponin%20in%20renal%20disease&topicRef=1469&anchor=H2&source=see_link#H2 
• https://www.uptodate.com/contents/elevated-cardiac-troponin-concentration-in-the-absence-of-an-acute-coronary-syndrome?search=elevated%20troponin%20in%20renal%20disease&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H23
• https://www.ncbi.nlm.nih.gov/books/NBK241525/pdf/Bookshelf_NBK241525.pdf

 

What is the difference between Temporary HD catheter, Tunneled HD catheter, AV fistula, AV Graft, peritoneal Dialysis.

A temporary HD catheter is also known as nontunneled hemodialysis catheter and is used when vascular access is required for urgent renal replacement therapy. The preferred placement for a temporary HD catheter is the right internal jugular vein followed by the femoral vein. These types of catheters are least effective for chronic kidney disease patients and are not intended for long term use. 

Tunneled HD catheters are indicated for a number of reasons. Chiefly they are used for temporary dialysis for longer than 2-3 weeks. They are also indicated for patients who are waiting for an AV fistula to heal/mature. They may be necessary in patients who cannot gain access in any other form or in patients who are using or plan on using peritoneal catheter. The preferred site for tunneled HD catheter is right internal jugular vein followed by the left internal jugular vein. Optimal placement is opposite the AV fistula site. 

An AV fistula is a procedure that connects an artery to a vein. For dialysis patients it is usually located in the forearm or upper arm and placed on the non-dominant side. An AV fistula is considered the gold standard for dialysis access. They last longer, are less likely to clot or become infected. However, they take time to mature. It may take up to 3-4 months to fully develop once the fistula has been placed. 

If fistula is not available then the next best option is an AV graft. The vein and artery are connected but with a synthetic tube. These may be ideal for patients with small/weak veins and is an outpatient procedure. The advantage is that they can be used for dialysis in approx 2 weeks and the patient may be able to advance the graft to a fistula if the veins get stronger. However, these grafts are more prone to infection and clotting because of the synthetic material. 

A peritoneal dialysis catheter uses the peritoneal membrane to clear the toxins. A dialysate solution is used to remove the toxins from the blood while injecting the solution into the peritoneum. The solution is kept in the peritoneal cavity for a couple of hours and then removed. The catheter needs to be placed in the abdomen near the umbilicus and secured in place. Advantages to having peritoneal catheter is there are no needles used like in an AV fistula/graft and dialysis can be performed at home. A temporary catheter is not needed. Issues may include infection and patients cannot get the site wet (no swimming or bathing). 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5332079/pdf/10.1177_2054358116669128.pdf

https://www.uptodate.com/contents/overview-of-the-management-of-chronic-kidney-disease-in-adults#H28