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Posts Tagged ‘door to balloon time’

Time is muscle. This quote  became  sort of ” cardiology sermon”  in the last  few decades .Cardiologist think  they stand  on a 100 meters sprint track once a patient with STEMI arrives .This is indeed true ,  if we  agree  time is  muscle and  our urge is to reduce the door to balloon time .Please  remember ,  this rush matters  much ,  only if the patient comes through very early  when the muscle is really getting damaged . (No issues  . . . even if the fire engine comes in  slow motion if the  house is burnt fully !)

Time is muscle agreed  . . .  but  muscles are  kept alive by  factors other than time  !  So muscles can  defy time if God  is willing !

Time is one of the important components of management of STEMI.  Other things matter too !  Age , baseline co-morbidity ,  underlying extent of CAD, collateral support of IRA territory , and finally  individual variation in hypoxic damage in myocyte is (Rarely  been studied in detail.)

Door  to balloon time for a patient  who lands up within  1 hour window need  to be  much  different from a patient who comes at 10 th hour .The issue is important  because  we use a procedure which requires delicate decision-making ,(IRA-Non IRA issues etc)  the results can be  sub optimal ,  and even be hazardous in low risk STEMI . So , door to balloon time  may be a less  important  component of  time window in a patient who comes after 6 hours .This is the reason  overall outcomes are not changing in a large cohort  of rapidly performed PCI.

The presumed  absolute  relationship  between  “Time  and  muscle”  concept is  always been a suspect . This  is proven by a flawless study from  NEJM .

nejm stemi most important article

http://www.nejm.org/doi/full/10.1056/NEJMoa1208200

This study should infuse more sense to  us ,  time and again, we are  hijacked and sedated by high dose of  pseudo scientific concoction .In fact ,  indiscriminate rapid PCI may not be in  the good interest of  all  patients with STEMI ,  if it is not properly done  .Without realising this fact many developing countries are indulging in extravagance of  costly STEMI programs wasting  the exchequer.

This landmark NEJM  paper convincingly underscores a fact  that  achieving  rapid door to balloon time  is not  going to be the game changer in  conquering  the Global   STEMI  championship  . We have to take the coronary care into the streets  or to their homes as well .This is where the pre-hospital thrombolysis will  emerge in a big way in the future .

A slow and steady thrombolysis beats a fast and furious primary PCI on any given day in all uncomplicated STEMI .This we have proven for over three decades in  one of the India’s largest coronary care unit .( Where is the data man ?  Genuine experience is data . Why  we require , the act of publication to convert an experience into evidence . Often times ,  I  would feel , data is the most unscientific word in medicine . Many Truths  lack evidence , false hoods come with plenty !  For all those  scientific  homo sapiens  , please recall  70 % of ACC/AHA class 1 recommendations are backed by level C evidence ie simple opinion from  perceived experts! )

Final message

A fast and furious primary PCI may not be  the answer in all STEMI population

Thrombolysis  can be  done  with near  zero time delay , it does not require special expertise where an ambulance driver can reperfuse   a myocardium without much fuss and glamor ! He does not have to  split his hair to identify which is the IRA in a complex multivessel STEMI as well ! The streptokinase and TPA will home in  to the target site  smoothly and swiftly .

If indeed ,  time is the major factor in STEMI , we have many other ways to tame  the time . If muscle is more important than time ,  pPCI is  rarely  the answer !

Some India specific  thoughts

Is it not a shame  , we talk about primary PCI  for all  our patients  who do not even get timely Aspirin* after a STEMI! .It is something akin to what we witness every day ,  as our country folks  wield touch screen  Androids  . . . conversing  in open air toilets !

* While the importance of  Aspirin is undermined , It is different story altogether , these patients  get sorbitarate promptly whenever they get chest pain  (mis-placed and  dangerous priority ! )  prescribed by the  roaring  GPs ,  who suffer from discontinuous medical education ,  propelled  by the deeply penetrated 1000 crore oral Nitrate market .

And STEMI workshops are conducted by self-proclaimed experts  every few months in posh  7 star hotels all over India .

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This article is in response to the prevalent belief  about  primary PCI for STEMI   endorsed by world cardiology forums. (Caution: A highly personalized version)

Time window in STEMI

  • Is the window half-opened  or half closed ?
  • Is it open at all ?
  • Or ,does it open only for primary PCI  ,and tend to close down  bluntly for thrombolysis

Modern medicine   grew faster than our thoughts .We have witnessed the audacity of advising  arm-chair treatment  for MI  till later half of   last century . Now we are talking about  air dropping of patients   over the  cath lab  roofs  for primary PCI.

Still ,we have not conquered the STEMI. While ,  we have learnt to “defy  deathin many patients  with cardiogenic shock , we continue to lose patients(“Invite death “)  in  some innocuous forms  of ACS due to procedural  complications  and inappropriate ( rather ignorant !) case selection.

Note : The ignorance  is not in   individual physician mind ,   it is prevalent in the whole cardiology knowledge pool.

The  crux of the issue for modern medicine is ,  how to reduce risk  in patients who are at  high risk and how not to convert a low risk patient into a high risk patient by the frightening medical gadgets.

In other  words ,  arm chair treatment for STEMI was  not (Still it is not !) a dustbin management . It has a potential to save  70 lives  out of 100. What many would  consider it as  ,  nothing but  the natural history of MI .

Medical management of STEMI is ridiculous !

That’s what a section of  cardiologists try to project by distorting the already flawed evidence base in cardiology. Some think it is equal  to no treatment. Here we fail to realise, even doing none has potential to save 70 lifes out of 100 in STEMI who reach the hospital.

Out of the  remaining , 10 lives   are saved by aspirin heparin (ISIS 2) and the concept of coronary  care . Another  7  lives are saved by thrombolysis (GUSTO,GISSI) . PCI  is shown to save saves one more life (PAMI).The remaining 6-7 % will die in CCU  irrespective of what we do .

Of course , now medical management has vastly improved since those days  .  A  thrombolysed ,  heparinsed ,  aspirinised ,  stanised  with adequately antagonized   adrenergic ,  angiotensin system   and   a proper coronary care ( That takes care electrical  short-circuiting  of heart)   will score  over interventional approach in vast majority of STEMI patients.

Now comes the real challenge . . .

When those 70 patients who are likely to survive  , “even a arm-chair treatment“, and the 20 other patients  who will  do a wonderful recovery with CCU care ,  enter  the cath lab  some times in wee hours of morning  . . .what happens  ?

What are the chances  of   a patient  who would otherwise be saved by an arm-chair treatment be  killed by vagaries of  cath lab  violence  ?(With due apologies ,statistics reveal  for every competent cath-lab   there are at least  10  incompetent  ones  world over !)

In the parlance of criminology , a hard core criminal may escape from  legal or illegal shoot out  but an innocent should  not die in cross fire , similarly ,  a cardiogenic shock patient with recurrent  VF  is  afford to lose his  life , but it is  a major medical crime to  lose a simple branch vessel  STEMI (PDA,OM,RCA )  to die in the cath lab,  whom in all probability  would have survived  the arm chair treatment.

Why this pessimistic view against primary PCI  ?

Yes, because  it  has potential to save  many lives  !

Time and again ,  we have  witnessed  lose of   many lifes  in many  popular hospitals in  India ,  where a   low risk MI  was  immediately  converted  to a high risk MI  after an primary  PCI with number of complications .

I strongly believe I have saved 100s of patients  with  low risk MIs by not  doing  for primary  PCI in the last  two decades.

*The argument that PCI confers better LV function and longterm  beneficial effect is also not very convincing for low risk MIs .This will be addressed separately

The demise of comparative efficacy research.

Primary PCI is superior to thrombolysis  : It is agreed , it may be  fact in academic sense .

Experience has taught us , academics rarely succeeds in the bed side.

“superiority studies can never be equated  with comparable efficacy”

Only the  questions remain . . .

  • Where  is comparative efficacy  studies in STEMI ?(Read NEJM article )
  • Why we have not developed a risk based model  when formulating guidelines for   primary PCI ?
  • Is primary PCI for a PDA /D1/OM infarct worth same as PCI for left main ?
  • Is high volume center guarantee  best outcomes ?

Who is preventing comparative efficacy studies ?

Primary PCI : Still  struggling !

This study from the archives  of internal medicine tells   us , we are still scratching  the tips  of  iceberg (Iceberg  ? or Is it something else ?)  of  primary  PCI

Even a  pessimistic approach can be  more scientific  than a optimistic  !

When WHO can be influenzed and make a pseudo emergency pandemic  and pharma companies  make a quick 10 billion bucks  ,  Realise how easy  it is  for the   smaller ,  mainstream cardiology literature  to be  hijacked and contaminated .

Final message

Why we reverently follow the time window for thrombolysis,  while  we rarely apply it for PCI ?   This is  triumph of glamor over truth . The open artery hypothesis remains   in a  hypothetical state with no solid proof  for over 2o years since it was proposed.

Apply your mind in every  patient , do a conscious decision  to either thrombolyse  ,  PCI or none . All the three are  equally powerful approaches in tackling a STEMI , depending upon the time they present .Remember , the third modality of therapy comes free of cost !

Never think ,   just because  some one  has  an access to a sophisticated cath lab 24/7   , has a iberty to overlook the  concept of time window  !

Remember  you can’t  resuscitate   dead myocytes , however advanced your enthusiasm and   interventions are !

Realise , common sense is the most uncommon sense in this hyped up human infested planet.

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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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