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Stable CAD strategies : Why a 90 % LAD lesion needs much attention … while a 100% doesn’t ?

Posted in cardiology -Therapeutics, tagged , , , , , , , , , on September 3, 2020|

           Practice of cardiology is simple as long we don’t dwell deep into coronary physiology.

One of my patients asked, why he was told his total occlusion in LAD appears safer now, which was subtotal a few months ago.I told him, it is indeed true. It is the fear of subtotal disease that’s prone to a fresh coronary event. In total occlusion, chances of that happening are less or nil.

 

How can you say 100% block is safe?  Is that always true?

No, it’s not always true. He was surprised when I said it is not 100 %, even 90% lesion can be safe if it’s not causing significant angina and responding to OMT. Of course, It is the morphology and stability of the lesion that will dictate* the outcome in the subtotal occlusion. If the lesion is stable, FFR is good >.8 (TMT is poor man’s FFR equivalent )  you can leave it as it is. Doing OCT /Virtual histology /NIR spectroscopy to define the vulnerability of plaque is neither practical nor desirable (Extreme academics is injurious to health) 

So it is not the degree of the block that’s going to matter, but the effects of that block on distal circulation that will decide the rules of the myocardial revascularisation game. But unfortunately, both you, (the patients) we (the cardiologist) are finding it so difficult to come to terms with this basic truth in spite of multiple guidelines. 

 

Meanwhile, CTO however makes it much easier to make a decision. One need not bother the content of CTO unless you plan an Intervention. I guess there is no FFR for CTO. Are we aware of any studies that have quantified antegrade flow across a 10% patent LAD and compare it with the Collateral flow in LAD in 100% CTO?

We have long glorified a concept of the open artery hypothesis. (Mainly in Post STEMI though) No one has dared to test and compare a hypothesis that a closed artery might still score over the open in at least some of the subsets of stable CAD. Such a study can never be ethically forbidden after all its a well-observed truth in the real world. 

Reference 

Trials on CTO  revascularisation DECISION CT (Not useful )   EURO-CTO  (May be useful) 

 

 

 

EURO CTO https://academic.oup.com/eurheartj/advance-article-abstract/doi/10.1093/eurheartj/ehy220/4990878?redirectedFrom=fulltext

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How to predict success in CTO : The Japanese CTO score sheet !

Posted in Cardiology -Interventional -PCI, Cardiology-Coronary artery disese, cath lab tips and tricks, cto chronic total occlusion, PCI PTCA Hardware, tagged , , on February 28, 2013| Leave a Comment »

Japanese are the pioneers in CTO reopening .(I understand they do less   CABG surgeries  for  religious reasons ) CTO is the ultimate test for cardiologist patience .  it may  take  hours to open up a CTO (or even to abandon it .)  Here is a  success prediction tool from Japan .

cto score success in chronic total occlusion

j cto score sheet

Source courtesy  : JACC: Cardiovascular Interventions Volume 4, Issue 2, February 2011

Reference

http://www.sciencedirect.com/science/article/pii/S193687981000912X

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CTO : The most important factor that determines the successful PCI ?

Posted in cardiology- coronary care, Cardiology-Coronary artery disese, cath lab tips and tricks, cto chronic total occlusion, Hardware techniques tips, tagged , , , , , , on February 27, 2013| Leave a Comment »

chronic total occlusion cto tips and tricks

Answer :

While each one of the above factor appears very much important  morphology of the lesion is the  clear winner  ( Which includes , the content of the lesion , hardness , micro channels , thickness of the proximal and distal caps, the length and   tortuosity   of the CTO     ( which is invisible ) the collateral status will ultimately determine the success)

It is becoming increasingly clear  cardiologist expertise is getting less and  less important .

Finally ,  it must  be told to our  younger generation of cardiologists , crossing a  CTO and deploying a stent  is not synonymous with success .It should result in long term sustained distal flow and make a significant impact on the patients symptoms (If at all any !) and survival.

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Arabian magic in cath lab !

Posted in Cardiology -Interventional -PCI, Uncategorized, tagged , , , , on May 5, 2010| Leave a Comment »

Chronic total occlusion is the cardiologist’s  daymare .Here is an article that adds on to 1ooth technique to cross the chronic total occlusion within the coronary artery !

If only we succeed in  this  Arabin magic , in the cath lab we can open the doors of  all CTOs .

This technique is based on the principle  to push the hard plaque  into the adjacent side branch like a sliding door,   if the pateint has one !

The only isssue  with this  technique  could be the    “cave door”  may close again immediately  as it did for Alibaba    !

Reference

 http://www.ncbi.nlm.nih.gov/pubmed/20088015

http://www3.interscience.wiley.com/journal/122619470/abstract

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Unusual seminars in cardiology :Ten simple ways to waste cardiology resources !

Posted in Cardiology -unresolved questions, Cardiology hypertension, cardiology- coronary care, Cardiology-Arrhythmias, Cardiology-Coronary artery disese, Uncategorized, tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on August 19, 2009| Leave a Comment »

  1. Do 64slice MDCT  in all patients who has  a coronary event and follow it up with catheter based CAG.
  2. Use liberally the new biochemical marker ,  serum  B-naturetic peptide (BNP) to diagnose cardiac failure in lieu of basal auscultation.
  3. Advice  cardiac resynchronisation therapy in all patients  who are in class 4 cardiac failure with a wide qrs complex .
  4. As it is may be considered a  crime to administer empirical  heparin, do ventilation perfusion scan in all cases with suspected pulmonary embolism.
  5. Do serial CPK MB and troponin levels in all patients with well  established  STEMI .
  6. Open up all occluded coronary arteries irrespective  of symptoms and muscle viability.
  7. Consider  ablation of pulmonary veins as an  initial strategy in  patients with recurrent idiopathic AF. If it is not feasible  atleast occlude their left atrial appendage with watch man  device.
  8. Never tell  your patients   the  truths  about the  diet , exercise &  lifestyle modification (That can  cure most of the early hypertension) . Instead encourage the  use of  newest ARBs  or even  try direct renin antoagonists   to treat all those patients in  stage 1 hypertension.
  9. Avoid regular heparin in acute coronary syndromes   as  it  is a disgrace to use it  in today’s world. Replace all prescription of heparin with  enoxaparine  or  still better ,  fondaparinux  whenever  possible.
  10. Finally never discharge  a  heftily  insured patient   until  he completes all the  cardiology investigations  that are available in your hospital  .

Coming soon :  10 more ways to  increase cost of cardiology care . . .beyond common man’s reach

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How to tackle CTO ? Japan shows the way – Welcome to the world of complex cardiovascular interventions !

Posted in Uncategorized, tagged , , , , , , , , on August 1, 2009| Leave a Comment »

Annual workshops for interventional cardiologists has been  hugely popular events.They have  become the forum for all technological breakthroughs. Some of the popular ones are

Japanese have gained a unique place in  complex cardiovascular  therapeutics interventions especially in chronic occlusions.

Landmark article for CTO crossing

cto chronic total occlusion Katoh coronary angiogram

www.cct.gr.jp/2003/wirehand/index.html

www.cct.gr.jp cto japan

How to reach Japan ?

Click below

CCT2010

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Coronary hemodynamics in 100% occlusion ?

Posted in Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, cardiology- coronary care, Uncategorized, tagged , , , , , , , , , , , , , , , , , , , , , , , on July 15, 2009| 8 Comments »

Total coronary artery occlusion is a common finding in CAD  especially in chronic stable angina. Normal coronary blood flow is 5 % of cardiac output  that amounts to 250-300ml/mt.At an average  heart rate of  70/mt  , each  beat  injects  about 5cc blood into the coronary circulation.This is shared between two coronary arteries.  This means , only few CC (2-3cc) of blood enters  each coronary artery with each cardiac cycle .

When one of coronary artery is totally occluded what happens to the coronary

blood flow ?

A.Total coronary blood flow  can be be  maintained   normal  at rest  as it  forms  only about 5% of cardiac output  (or it is only  slightly reduced )

B. It is believed , the unobstructed coronary artery  could receive the blood meant for the contralateral coronary artery. This  possibly explains the increased coronary artery diameter in the non obstructed artery.

C. It’s nature’s wish ,  that the  contralateral  coronary artery  shall share  50% of  it’s  blood through  collaterals if available.

D.If collaterals are not formed it , the unobstructed coronary  artery  may be over perfused with double the amount  of blood flow.

E. Some times , the collaterals steal  much more than what  the  obstructed coronary artery  deserves and make the feeding coronary artery ischemic. This is many times observed in  total RCA occlusion with well formed  collaterals  from LAD/LCX.

F.The collateral flow  in CTO also depend on whether flow is directed from LAD system to RCA or from RCA -LAD system. The LAD is better placed to assist RCA than vice versa.This is for two reasons.1.LAD blood flow is higher than RCA so it can share it.2.The driving pressure is more  from LAD -RCA , as RCA can receive  blood flow even during diastole .

F.During exertion , the coronary hemodynamics become further complex.The collateral’s are traditionally thought to be less than adequate during times of exercise.But it is more of a perception than solid scientific data.This rule  may be applicable in only certain group of patients. We know CTO patients with very good exercise tolerance who have documented collateral’s.

G.Collaterals can be either  visible or invisible by CAG. The strength of collateral circulation is not in it’s visibility but it’s capacity to dilate and  respond to neuro humoral mediators at times of  demand.  Currently  , there is lot to be desired  regarding  our knowledge about  the physiology  of visible collaterals , no need to  mention about invisible collaterals !

Final message

The above statements  are based  on logics and observations .

Is it not a  irony  in cardiac literature ,  where  thousands of articles  are coming out every month  to tackle  totally occluded coronary artery(CTOs) ,  there is  very little data   regarding the coronary hemodynamics in chronic total occlusion .   How  does a patient with CTO can manage a active life with only one functioning  coronary artery ?

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Is there a time window for rescue PCI ? Why we are not insisting on it ?

Posted in cardiology -ECG, Cardiology -Interventional -PCI, cardiology -Therapeutics, tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on May 25, 2009| 1 Comment »

Failed thrombolysis is an important clinical  issue  in STEMI   as  successful thrombolysis  occurs  only in  about 50-60%  of pateints . The typical criteria to define failed thrombolysis is  the  regression  of less than 50% of sum total( or maximum)  ST elevation in infarct leads.

So what do you do for these patients with failed thrombolysis ?

It depends upon the patient’s symptom, hemodynamic stability, LV dysfunction .

They  should  get one of the following .

  1. Conservative medical management  with /without CAG
  2. Repeat thrombolysis
  3. Rescue PCI
  4. CABG

Medical management is  thought to be  too inferior a  management,  many of the interventional cardiologists  do  not want to talk about . But  , there is  an important  group of patients (Not often addressed in cardiology literature)  who  technically fulfill the criteria  of failed thrombolysis  , but   still  very  comfortable , asymtomatic  and in  class 1. These patients ,  have  a strong option for continuing the conservative management .

Repeat thrombolysis does not have a consistent effect but can  be  tried in some  stable patients. CABG  can be a genuine option in few

Rescue PCI

This terminology  has become  the  glamorous one since the  catchy word  rescue is tagged in the title  itself. For most of the cardiac physicians ,  this has become the default treatment modality.This is an unfortunate perception . What  one should realise   here is  , we are  tying to rescue  the myocardium and  the patient ,   not the patient’s coronary artery !

Opening up a coronary obstruction is not synonymous with rescue .

For rescue PCI ,  to be effective it should be done within the same time window as that for thrombolysis (ie within 6 or at the most  12 hours) .This timing  is  of vital importance  for the simple reason , there will be nothing to rescue after 12 hours as most of the muscle  would be  dead. Reperfusing a dead myocardium has been shown to be hazardous in some ,  as it converts a simple  infarct into a hemorrhagic  infarct.This softens the core of the infarct and  carry a risk of rupture. Further,   doing a complex emergency  PCI  ,  in  a thrombotic milieu with   presumed  long term  benefit ,  is  a  perfect recipe for a potential  disaster.

While the above statement may be seen as pessimistic view , the optimistic cardiologist would vouch for the“Curious  open artery hypothesis” .This theory simply states , whatever be the status  of the distal myocardium ( dead or alive !)   opening an obstruction in the concerened coronary artery  will benefit the patient !

It is  huge surprise , this concept   continues to  be alive even after  repeatedly shot dead by number of very good clinical trials (TOAT, CTO limb of COURAGE etc ).

The REACT study (2004) concluded undisputed benefit of rescue PCI for failed thrombolysis  , only if the rescue was done  within  5-10 hours after the onset of symptoms.The mean time for  pain-to-rescue PCI was 414 minutes (6.5hours)

Final  message

It is fashionable to talk about time window for thrombolyis but not for PCI  .The time window for rescue PCI is an redundant issue  for many  cardiologists ! . But ,  the fact of the matter is ,  it is not . . .

The concept of time window in rescue PCI  , is as important as ,   that of  thrombolysis. Please , think twice or thrice !  if some body suggest you to do a rescue PCI in a stable patient  ,  12hours after the index event .

Important note : This rule   does not (  or need  not  ) apply for patients in cardiogenic shock  or patient ‘s with ongoing iscemia and angina.

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Can coronary collaterals provide more blood flow than a CABG ?

Posted in Uncategorized, tagged , , , , , , , , , , , , on March 29, 2009| Leave a Comment »

Coronary collateral circulation is the most poorly understood, and often neglected concept among the cardiology community.There is a general perception , in obstructive CAD ,  coronary collaterals are an inferior modality of  back up blood supply than artificial collateral (Also called CABG ) ! One of the reasons,  it is   been ridiculed by many  mainstream cardiologists is   because  , it comes by nature , and also free of cost !

The often quoted statement* ,collateral blood flow can not sustain blood flow during exercise ,  is not based on solid scientific data. In the real world , there are thousands of patients actively pursuing life with chronic total occlusion and good collaterals.

It is surprising , there is no  physiologically valid ,  controlled study available to compare CABG with natural collaterals

*When repeatedly told , a  statement becomes a fact !

It can be assumed (Unscientifically ofcourse ! )   the  remarkable  success  of medical therapy  in COURAGE  and the OAT * study  can be attributable to the naturally occurring coronary collateral circulation.

* Summary of COURAGE & OAT : A   block  in the coronary artery  need not be opened  to prolong human survival !

You draw your own conclusions from the  following case study

A 40 year old women , with stable angina and good physical activity

Her angiogram shows.

coronary-collateral-2

RCA injection

coronary-collateral

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Guideline violations in cardiology practice : Every body does it , so do I !

Posted in Cardiology -Interventional -PCI, cardiology- coronary care, cardiology-ethics, tagged , , , , , , , , , on August 24, 2008| Leave a Comment »

All is not well,  that ends well !

                                       Treatment guidelines in cardiology  practice  are periodically published by ACC/AHA/ESC.These guidelines  represent the current scientific practice. They are called some times as recommendations. Medical professionals tend to adhere to this guidelines whenever possible.They are not legally binding in most of the countries.In USA some states believe it, to be legally binding.

 

The problem with these guidelines  are , they are classified as class 1 ,class 2 , class 3 recommendations.

 

Class 1, A  drug , device  or a procedure  Is definitely useful and must be prescribed.

Class 3,   A  drug , device  or a procedure  Is not useful and should not be used .

Class 2*, A  drug , device  or a procedure  may be useful  or may be harmful , and hence may be used or may not be used . (Vaguest possible guideline!)

 *Altered to convey the meaning

What are the  guideline violations that can be sued in court of law  ?

A person with established  CAD who is not been prescribed a  statin (Cholesterol lowering drug)  can be sued straight away,  even if the patient has no adverse outcome due to the nonprescription of that drug. The issue here is , the doctor  has not prescribed  a drug which has  proven benefit .The law is clear on that .Most will  agree that,  the  doctor is at fault ,  and he  is never protected  even by their  colleagues .He  can’t defend his action.

What are the medical errors that can never* be sued in court of law !

But the same doctor who opens up a totally occluding coronary artery in an asymptomatic patient(CTO -chronic total occlusion) and lands up  in a complication and the  patient dies. This could be  major guideline violation as opening a CTO in an incidentally detected , asymptomatic patient is a class 3 recommendation. Neither the physician, patient , institution  nor  the regulatory authorities bother about this even though there is strong case for censure , in reality it never happens. Number  of  experts from leading hospitals do this procedure in live work shop all over the world with full media glare, It is an irony the same  experts are only  writing  in their  guidelines  that  these procedures should not be done inappropriately.

And this medical  error ( Should we call it a  crime if it is knowingly done ! )   keeps growing as the physician never feels guilty about it .

The message here is

 A physician of a state of the art hospital,  in a scientifically advanced  country  goes scott free and guilt free  even if he openly violate the scientific guidelines and do a inappropriate procedure that result in a patient death. Mean while a small time physician in a remote place in the same country can be taken to task  for not prescribing a officially  recommended drug (By standard guidelines) .He will be labelled unscientific and unethical even if his non prescription , had not caused any untoward health outcome .

In short , in today’s modern medical practice 

 Even a  ” Minor error of  ommision”   attracts guilt and perceived fear among the physicians. Meanwhile  many  of the ” Major errors of commission”  done by professionals are rarely frowned upon and thus these  mistakes continue to perpetuate !

*There should be a strong provision in medical law to address the issue of inappropriate procedures even if the procedure has not resulted any untoward effect to the patient.

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