Silent Myocardial Ischaemia, CKD a Deadly Combination

[okarol]

Silent Myocardial Ischaemia, CKD a Deadly Combination: Presented at NKF

      By Carole VanSickle Ellis

      ORLANDO, Fla -- April 19, 2010 -- A study examining the relationship between silent myocardial ischaemia (SMI) and chronic kidney disease (CKD) shows that the 2 conditions combined are often fatal.

      In fact, patients with both CKD and SMI had a lower chance of long-term survival than any other group in the study, researchers said here on April 16 at the National Kidney Foundation (NKF) 2010 Spring Clinical Meetings.

      Ammar Almehmi, MD, Division of Nephrology, University of Kansas' Kidney Institute, Kansas City, Kansas, and colleagues enrolled 356 men and women who had undergone percutaneous coronary intervention (PCI).

      SMI was defined, for the purposes of this study, as the absence of chest pain in response to the PCI. Estimated glomerular filtration rate (eGFR) was used to categorise patients as having normal renal function, mild renal dysfunction, moderate renal dysfunction, and severe renal dysfunction.

      Compared with patients with normal renal function, the multivariable adjusted hazard ratios for all-cause mortality among patients with mild, moderate, and severe renal impairment were 1.11, 1.75, and 2.79, respectively.

      Patients with both eGFR <=60 mL/min and SMI had a worse survival compared with those with eGFR >60 and no SMI.

      Given that the prevalence of sudden cardiac death among patients on dialysis is 20 to 100 times higher than the general population, these findings may underlie the increased mortality in patients with depressed eGFR, the researchers said.

      The researchers were also able to conclude that eGFR is a graded and independent predictor of long-term mortality in patients with CAD.

      [Presentation title: Silent Myocardial Ischemia and Chronic Kidney Disease: The Fatal Dance. Abstract 36]

http://www.docguide.com/news/content.nsf/news/852576140048867C8525770A0051F8AF

[Hemodoc]

I believe that silent myocardial ishemia is the smoking gun of sudden cardiac death in dialysis patients.

[Sunny]

Is dialysis itself is a contributer?
Or is it simply low eGFR?

[Rerun]

Any symptoms prior to dropping dead?

[Hemodoc]

Silent myocardial ischemia during dialysis is a well documented phenomenon, but it seems to stop right there as so many other things in dialysis.  Ischemia is simply a mismatch between oxygen demand and oxygen delivery of which many factors contribute such as hemoglobin levels, blood flow rates and other physiologic parameters.  One of the most interesting factors that I have found when researching this issue last month was the vasoconstriction associated with lowering potassium levels with dialysis.

http://www.billpeckham.com/from_the_sharp_end_of_the/2010/03/1974-physiology-article-local-hypokalemia-produces-dramatic-coronary-vasoconstriction.html

I had an entire series on this issue, what is the cause?  To date it is unknown and I can't see that it is getting the fair share of attention that it deserves.  How many times have I heard that we don't have an explanation for sudden cardiac death in dialysis patients yet most nephrologists are not even aware that silent myocardial ischemia has been documented for well over a decade in our population.  After a while you begin to wonder if they even care.

http://www.billpeckham.com/from_the_sharp_end_of_the/2010/03/what-is-the-cause-of-dialysis-related-myocardial-ischemia.html

[Sunny]

Thx Hemodoc. I'll make sure to read your articles on Billpeckham.
You would think the medical community would want to look into this a little more.