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Archive for the ‘Cardiology -Interventional -PCI’ Category

If human coronary artery is comparable to live wire , attempting  bifurcation (BFL) stenting is akin to tame a live snake .True BFL  (with Medina 1, 1, 1)  being the most complex of all .The fact is ,we have atleast a dozen strategies for BFL with varying loads of metal abutting the ostia ,side branch and carina.This  would essentially Imply we are still struggling with these lesions .

While current science tends to vouch PCI* for most  BFLs . . . wisdom  might whisper CABG !

Who should do complex PCI ?

Obviously,  not every interventional cardiologist can. Confidence is one thing , but , falling short of minimum standard of care is rampant in India. Newer Imaging tools, techniques are promising , unfortunately  still the gap between, knowledge , science and  reality continue to widen.

* Its true ,some expert Interventionists do a good job !

What is the simplest approach for Bifurcation lesions ?

Final message 

We have come a  long way in BFL. Still , some of the lesions can sting  like a snake ! I am sure, everyone of us would have lost sleep after a complex BFL PCI !( Praying the humble  heparin and DAPT to do the rescue act ! )

bifurcation lesions medina stenting srategies 002

How to escape this double headed threat ?

A meticulous assessment of  patient  &  lesion , mindfulness in choosing the hardware & Imaging , diligent usage of anticoagulants & DAPT and  . . . finally  willingness to listen to your own conscience ,  will ensure a gratifying result that includes abandoning the procedure !

Reference 

For everything in Bifurcation Intervention

The ultimate source : Visit the in this link  European Bifurcation  Club

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Some of the noise bites from a busy cath lab after a  mid noon angioplasty

         Oh’  that  looks bad , whats that projecting !

There is some haziness too ,

            Make sure its not a flap,

  Better to do IVUS or should I OCT ?

           Shall I  post dilate with NCB ?

Should we cover with  another stent ?

           I think we can manage with Tirofiban or Reopro 

Call the chief ! suggested a first year resident,that seemed to be the most reasonable noise bite among all .Yes, the final command came from the chief cardiologist after a 10 second glance over the workstation ,”Guys,  forget it , . . its acceptable  pinching, DAPT will take care of it , just ensure adequate ACT till night , put the next case . . .on table” !

That’s fairly common chat session in any high volume cath centres (Which ended abruptly  in this case with the chief’s uttering)

Does any body know  what the chief meant by  the term pinching ?

  • Is it the  pinch of Intimal fold ?
  • Is it pinch of plaque ?
  • Is it a flap ?
  • Is it a plaque prolapse within the strut ?
  • Or just a evaginated thrombus
  • A subintimal calcium speck ?
  • A longitudinal stent deformation?

Any one knows the histology ? Is there any natural history  study of such pinching ?

Iam afraid no one knows . But common sense tell us it can be anything  between a totally benign entity to  Imminent nidus  for an acute stent thrombosis , depending upon the patient’s destiny and physician’s luck !

How does one make a decision in such an uncertain situation ?

The decision to leave that pinching is taken by any  cardiologist  based on his past experience or  Inexperience or both. Some do IVUS/OCT , many don’t . Whatever the decision  ( empirical or scientific ) its  going to be tentative  and  outcome is any body’s guess.

Final message

Coronary arterial pinching is a dangerous cath lab slang used exclusively by expert Interventional cardiologists , often after a hurried PCI ! It may sound  innocuous .To label a protruding plaque as a “safe pinch”demands heavy courage that is an essential requirement  for a successful Interventional  cardiologist , which most of them are blessed with !

Reference 

1.No Reference as such :There is no specific study about histology of coronary pinching  .Though , IVUS and OCT data are available for various post PCI shadows , it never addresses the issue of pinching specifically as no one is clear about what they mean by it.  Hence ,we are planning to decode this long pending mystery with our own  PINCH-iVUS  study.

2.This article from Circulation Imaging  new generation IVUS could reveal  histology of pinching

f5-large

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This paper was presented as a poster (Not good enough for  oral ! ) in the just concluded CSI 2016  (Cardiological society of India ) Annual conference at Kochi, India.

 

What constitutes successful  Primary PCI ?   A proposal to include “ LV dysfunction”  as an  essential  criteria !

A  series of breakthrough technologies  in drugs , devices, techniques has revolutionised the management of STEMI in modern times.This  includes various formats of heparin , antiplatelet agents thrombolytics  and coronary interventions.Of all these, primary PCI is considered to be the greatest thing to happen in STEMI care.

The success of primary PCI is currently defined as diameter stenosis less than 30% and TIMI 3 flow on final angiography without procedural complication. True success of reperfusion essentially lies  in the salvage of myocardium and in the prevention of LV dysfunction. In real world scenario we often find a paradox , ie Inspite of  successful pPCI by current definition a subset of patients suffer from significant  LV dysfunction. Surprisingly, LV dysfunction has  never been included in the definition of successful primary PCI .

success-of-primary-pci

In this context we did a reversed cohort  study  of patients with significant LV dysfunction (<40%) following primary PCI to find out possible factors contributing to LV dysfunction.10 patients who had LV dysfunction inspite of successful primary PCI were the subjects of the study. Patients with late PCI  beyond 12  hours were excluded .Echocardioraphy had been done at discharge and 2 weeks after the procedure to assess LV function.

TIMI  3  flow  has been  documented in all  patients at the time of primary PCI.6 patients had undergone pPCI within 6 hours.4 had it by 12 hours. 7 patients had a smooth , fast  pPCI as described by standard protocol.Of these,  2 patients had LV dysfunction inspite of TIMI 3 flow established early.7 patients 3 had complex angioplasty with no reflow managed subsequently.One had deferred stenting after 4 days for IRA.Non IRA lesion were also  tackled in two.

We also confirmed  there is no linear no correlation  between TIMI flow and  subsequent LV function .This becomes vital as time and again we are seeing PCI reports with successful TIMI 3 flow only to find  weeks later  thinned scarred ventricle. Time to reperfuse with anticipated and unanticipated procedural delay  was also  a critical  factor.

However, its clear the  incidence of significant LV dysfunction inspite of  timely, and apparently smooth  PCI is real .Why this happens is beyond the current reasoning. A scientific basis for  individual myocardial sensitivity to ischemic time is yet to be found. (Dynamic host dependent time window ?)

Meanwhile , It seems prudent , we should awake to a harsh reality of practicing coronary care  with a seemingly incomplete criteria for success of pPCI . Its proposed,  an  acceptable levels of  “LV dysfunction at discharge ” (It could be > 50 %) as an essential criteria  to define the success of pPCI  .Custodians of STEMI care should  immediately rectify this glaring omission. This will dramatically impact the current  outcome analysis of STEMI and help Improve the quality of care.

Conference bulletins

dr-venkatesan-e-poster

E-PosterPresentationSat10thDec csi cohin 2016

Session – Preview 

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Originally used in early 1990s,  self expanding coronary stents (Wall stent from Boston scientific )  subsequently lost interest because of delivery related issues. Many feel , it makes cardiologist judgment tentative and delivery system prevail over our hand skills. It is possible stents can longitudinally jump with high radial force making a geographical miss more likely.While it could be true with any technique till we master it, one should recall ,most endo-vascular work other than coronary still involve self expandable techniques.

Balloon expandable  stent is ruling the PCI field  for more than 2 decades. There has been recent surge of interest in the self expanding  technique and it could make a great difference in the PCI arena provided we take the proper cues.

Self expanding stents have some unique advantage

  • It has  high radial force.
  • Approximation with lesion is best
  • It tends to take the shape of the vessel than any other stent
  • Since the mal-opposition and gap between stent and vessel wall is minimal stent thrombosis is theoretically is  lower.

Where is self expanding stent useful ?

  • Ectatic and very irregular lesions
  • Bifurcation lesions where multi dimensional vessels with different shaped ostia converge.
  • Eccentric lesions (Non calcified) may be benefited by self expanding stents
  • Self expanding covered self (Is it available >)  may be the best bet for perforations and for thrombus  to be plastied against the wall.
  • In some small vessels PCI
  • Finally it may have a  role in primary PCI (APPOSITION 1 to 5 )

What are the self expanding stents available ?

  1.  Devax system   ( 2003)
  2.  Stentys
  3.  Radius (Boston scientific)
  4. Capella Sideguard.
  5. Cardiomind Sparrow
  6. vProtect luminal shield.

Final message

For some reason , self expanding stents were not tested widely  and  large scale data is not available. However ,  they are unique modalities in metal delivery and must be mastered and many patient subsets will be benefited by it. They are not obsolete yet, APPOSITION 5 study will answer some of the issues.

Reference

1. Agostoni P, Verheye S. Novel self-expanding stent system for enhanced provisional bifurcation stenting: examination by StentBoost and intravascular ultrasound. Catheter Cardiovasc Interv 2009;73:481
2.Jsselmuiden A, Verheye S. First report on the use of a novel self-expandable stent for treatment of ST elevation myocardial infarction. Catheter Cardiovasc Interv 2009;74:850
3.Verheye S1, Grube E, Ramcharitar S, Schofer JJ,.First-in-man (FIM) study of the Stentys bifurcation stent–30 days results.

EuroIntervention. 2009 Mar;4(5):566-71
4. van Geuns  R.-J., Tamburino  C., Fajadet  J.,  Self-expanding versus balloon-expandable stents in acute myocardial infarction: results from the APPOSITION II study: Self-expanding stents in ST-segment elevatation myocardial infarctiion. J Am Coll Cardiol Intv. 2012;5:1209-1219.

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A patient with near 90% LAD disease who had a significant TMT/EST positivity with no clinical angina  was  subjected to FFR by a scientific  cardiac physician. Since FFR was recorded as  .9 , he was adviced against a stent and sent home with drugs.

Now , in the  physiological assessment of a coronary lesion ,  which one you are going to trust , TMT positivity or FFR ?

FFR  measures trans-lesional pressure drop  by creating a artificial exercise physiology  in a particular coronary bed by injecting just one of coronary vasodilators  namely Adenosine. FFR assessment can never be considered truely  physiological .There has been huge discrepancy in the amount , rate and route of administration and the hyperemic response to Adenosine.

Final message

In a single vessel disease population , if TMT is positive the lesion is to be taken as significant, irrespective of FFR.(Provided Anemia and other systemic factors are excluded )

*Read this and get ready to get  confused further , single vessel disease with TMT positivity  doesn’t mean medical management is never an option .OMT ,(optimal medical therapy ) even though a battered concept is not yet dead for SVD !

 

 

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Every one talks about  coronary excesses ! It happens  both  in acute and chronic  fashion , not withstanding the inappropriately  understood  . . .   appropriately  released  guidelines  on inappropriateness ! The  burden  of coronary syndromes of the humanity, I am afraid would  include these man made excess as well !

I stumbled upon two  small  “gems ” in this other wise wild dark  cardiology literature  .One from Kamaer , Netherlands and other from  Escaned from Spain.

Both  talk about a  simple and logical modality in the management of STEMI . If bulk of the STEMI events are due to coronary thrombosis just tackle it  . No more  . . . no less” Stent only , if there is tight residual lesion.

1. From Amsterdam , Holland.

krammer thrombus aspiration alone priamry poba for stemi no stent

2.This one is from Spain.These studies I am sure , only a fraction of the interventional community would have read .Reason ? We are always hijacked by the moments of glamor ! I am just sharing them .hope few are benefited

primary POBA thrombus aspiration alone for stemi no stent stemithrombus aspiration alone for stemi no stent priamry pobaThese two studies with total number of 44 patients has a potential to redefine  the entire practice pattern of acute interventional coronary care.(Of course , if only , we are ready to make sense out of it !)

But , the concept will be heavily banished by strong visible and invisible forces   for the simple reason it suggests a true possibility  of knocking  out the role of  stent from acute STEMI arena.

When I discussed with my colleagues  for a large scale study  on isolated thrombus aspiration in STEMI , they told it  is not possible for ethical reasons !

I was amused , denying such a study is biggest ethical blow to the field interventional  cardiology !

Final message

Proof of concept does not require numbers .A study with less than 50 subjects  can be far superior than multi-centre ,multi-blinded , self steered ,peer reviewed largesse ! The truth of the study lies in the core consciousness  of people who do it , not in the numbers and exotic statistical methods !.

After all , one of the greatest medical study  was  done by James Lind  (Father of RCT) who discovered vitamin c as an antidote for scurvy,  with a hand full of sailors  while they crossed the Atlantic many centuries ago !

After thought

You say , thrombus aspiration is great , Why the hell , TAPAS , INFUSE AMI, and TASTE studies  confuse us regarding thrombus aspiration  ?

Don’t blame it on thrombus aspiration .We do it perfectly . It is because of what  we do after that ! We decorate the coronary lumen finally with a piece of metal cherry  undoing all the goodness of a great pudding !

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Aorto ostial  stenting requires extra caution and special technique. It always  worry us  what if  few mm of  metal might project into Aorta when we stent a RCA or left main ostium.

To  prevent this ,Merit- medical  has innovated a catheter that help us position the stent exactly at the ostial level .It is  done  with a help of an octopus like buttressing arm that support the aortic wall when the stent is deployed .

Watch the video.

 

Reference

Merit-medical 

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