Posts Tagged ‘physiological impact of anatomical lesion’

  1. The concept of  FFR is based on pressure gradient  alone.In any hydraulic model (Both biological and non biological systems ) pressure difference  is the least   important parameter  that determines flow.
  2. FFR  is unphysiological  as hyperemia   is  artificially induced one .(Adenosine  is not the only parameter that determines it !)
  3. Serial obstructions and branch point hemodynamics are  conveniently ignored.
  4. Reproducibility  remains a big question mark .
  5. On safety  issues  FFR  is a suspect.( Often times , it  requires expertise comparable to  that of a  complex  PCI !) .Beware , the FFR unit has stiff catheter system and is an additional health hazard .  I have witnessed   atleast two cases  where  insignificant lesions were  made significant by  FFR related Injury .
  6. And  now the  knock out punch ,  ! Probably the most vital  issue for which FFR should be banished * , it is not taking into account of vulnerabilty of a plaque .( An FFR > .9 with a hanging , eccentric , mid LAD lesion was left alone by one of the  academically up to date ,  evidence  based interventional cardiologist!  )
           (*If perfomed  in isolation without IVUS/OCT  )
I am still wondering how this concept came into cardiologist domain and into the cath lab .It should have  never been let out of theoretical physics labs !
Final message
The best way to assess physiological significance of an anatomical obstruction is  to  do  exercise  stress test .
If  the lesion is  able to sustain good exercise capacity , it  can be deemed physiological unimportant.
While , this is an explicit  proof  in single vessel disease  ,  even  in   multivessel  CAD ,   EST  is   a  collective  measure of  coronary  reserve flow .( Something like instantaneous equivalent of virtual  multivessel  FFR  )
Moderated After thought
FFR is a highly specialized theoretical  tool , that has very limited role in cath lab .
The two major practical (Non academic)  use of FFR   is to shun away  those   internet fed ,  annoying, pseudo  intellectual patients ,  who constantly ask for  angioplasty  for  obliviously insignificant lesions !
FFR comes very handy  to  bail out  cardiologists at  times of distress   ! (To escape  from the wrath of our patients   after a sub optimal &  technically inferior   PCIs   and   in  the  long term confabulations  in   restenosis  after stenting !  )


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