Posts Tagged ‘csa’

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Chronic stable angina : Most can be effectively managed  by  optimal /intensive medicines and life style Interventions .About 10% will require PCI/CABG.

ACS – STEMI:  Primarily  managed  with  rapid and competent  pre-hospital care with prompt thrombolysis in or out of hospital .Patients  with  large STEMI who develop complications (Again about 10 %)   require PCI and few additional  lives can be saved.

ACS-NSTEMI : This is  the group that demand  an  important role for PCI . All true high risk UA/NSTEMI patients  should receive urgent coronary  angiogram and critical lesions  should either be stented or  sent for CABG  (If the lesions are multiple and complex ) The field of interventional  cardiology  is  expected  to play a major  role in  this category of  patients for the simple reason , we  not only give dramatic  relief from angina and also prevent a  potentially a huge MI that is waiting to happen !

* It is vital to emphasise  the “Aim and  objective” in  NSTEMI  management  is critically different from other two. We know ,  in CSA   the aim is to give relief  symptoms  and improve excercise capacity . Both PCI/CABG  are  unlikely  to prevent a future MI in CSA..In STEMI it has already occurred .The aim is to salvage myocardium  and prevent  future events. While PCI can do the former , it can’t do the later . In STEMI scenerio ,we have very good  alternate  modality called thrombolysis which can easily beat the  pPCI  in , cost , availability and time  (and  hence efficiency as well  in  most  countries !)

Counter thought

The above suggestion  is too simplified ,generalized , misleading , and  unscientific, should   strongly be disagreed. For those people who disagree , I provide an alternate scheme  .It is ultra short ,comes in  5 lines .Very practical  and  scientific too  !

In any  patient , who is  suspected to have either  acute or chronic  coronary syndromes ,take them to the cath lab in an  urgent or semi urgent fashion .Do an angiogram and stent all lesions  that you feel important . If  stenting is not possible  manage  with optimal medicines and /or send them to the surgeons.

Final message

The essence of catheter based coronary care is simple.We complicate it. To understand this concept  100’s of cardiology  journals  and as many conferences and infinite  number of books are churned out every year !





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Acute coronary syndrome  is primarily a disease of blood vessel , which perfuses  the heart.  It can even be a disorder of blood, often called vulnerable blood which predispose  for intra- coronary thrombus .

Mind you  , heart is an innocent bystander ! to the onslaught of  coronary atherosclerosis !

Hence , we  often use two terminologies .

CAD : Pure vascular (Coronary )  disease without  any structural and functional impairment of heart  ( No Angina, No myocardial damage ) Most of the asymptomatic plaques  , non flow limiting  lesions, incidentally detected by the modern coronary imaging gadgets  fall in this category.

When does  CAD becomes CAHD ?

CAHD : Coronary artery heart disease .Here not only the coronary artery is diseased , but it has it’s mission fulfilled   ie target organ either damaged structurally (STEMI, NSTEMI ) or functionally (EST positive , Chronic stable angina CSA )

Does the heart does any wrong to suffer from Acute coronary  syndrome  ?

No, it is simply not .The fault lies in one or more  of the following   .Generally at-least two these factors are enough to impede blood flow )  . They  combine to produce an ACS.

  • Blood defect
  • Vessel wall defect
  • Slowing of flow (Stasis)

This is called as Virchow’s triad   suggested over 100 years ago . Still valid in the era of per cutaneous  aortic valve implantation.

* The concept of de-linking  disorders of  coronary  vascular disease  from myocardial disease  is vital  in understanding the implications of current modalities of treatment. 

Even though we PCIs target the culprit ie blood vessel , it need to  realised , we  always fall short of real target . . .namely the heart . In coronary interventions  the catheters and wires roam around superficially over the heart  and they never even touch the heart .This is the reason PCIs are struggling to prove it’s  worthiness over medical therapy in many CAHD patients , which can reach deep  into the vessel, heart  and even every individual cells of heart.

Many (or . . . is it most ?)  Interventional  cardiologists have a bad  reputation for ” failing to look  look beyond the lesion” .  It is estimated  a vast  number  of cathlabs  and CABG theaters worldwide  are engaged in futile  attempt to restore coronary artery patency after a target organ damage is done .This is akin to building flyovers  to dead and closed highways .

Salvaging a coronary  artery and reliving a coronary obstruction is an entirely unrelated and futile  exercise to  a patient who has a problem  primarily in  musculature .

The much debated concept of  documenting  myocardial viability  , before revascularisation  died a premature death as the concept  by itself , was not viable commercially . (Viability studies   , tend to tie down the hands of device industry further , some  interventional   cardiologists began to see this concept  as an  interference to their freedom to adventure  )

Of-course , now  we have  other parameters  phenomenon  like  FFR estimation by Doppler , epicardial  -myocardial dissociation, slow  flow , no re-flow are  gaining importance.

Final message

ACS is primarily a disease of blood vessel but it’s impact is huge on heart. We need to look beyond the lesion .Restoring  a blood vessel  patency  to an ailing organ (Heart ) is not synonymous with total  cardiac intervention  and protection . There is lot more to cardiac physiology other than it’s blood flow. Heart muscle is a too complex organ to be controlled by few balloons and wires  which beat around the bush.

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Medical profession has  evolved over centuries with humble discoveries by genuine researchers in the past . As we  pursued  science vigorously  , we  looked  for innovations , when innovation  work ( or many times shown to work !) we jump to sky , even as  some of these  innovations fail and crash down  to earth , many times  we continue to be in the clouds . This is the fundamental problem of modern medical science . When  our expectations reached  unrealistic proportions ,   we tend to lose the common sense . Prolonging life and reducing human suffering may be the ultimate aim of the medical  profession , but  If we try to fight the death with science and money without application of mind , our current  life may become  miserable ! Thats what is happening for the majority of the population of this planet . After all ,  death is an essential and final  component of life !

Coming to the issue of CAD ,  in our country , a  rich gets a 4th generation drug eluting stent for a insignificant  asymptomatic PDA lesion , and poor fellow with left main dies without any intervention .This is  fairly acceptable   to this uneven world  , where a rich westerner  dies due to obesity related disease and a  poor African dies to malnutrition .

This article is in   response to  my  recent  experience  when  . . . I advised

Simple life style modification &   few drugs   for a patient with chronic multivessel   CAD  , I was  made to look   ordinary , inferior  and funny   by  many of the current generation cardiologists .

Further , the term optimal medical therapy(OMT)  for chronic stable angina has evoked laughter in one of the interventional cardiology  conferences  I  attended !

It is a sorry state of affairs  for the whole cardiology community , a  genuine scientific  fact , proven by  real life experience  as well,   is  being  ridiculed.

Richard  Conti tells in this excellent editorial in his journal   Clinical cardiology about the issue of medical management of CAD

“Respect in clinical trials”

Chronic stable angina pci vs cabg vs medical courage trial oat trial ethics in cardiology

Click here to reach the article  http://www3.interscience.wiley.com/cgi-bin/fulltext/122512853/PDFSTART

A similar study which  suggested  exercise  could be  better than PCI in the recent 2009 ESC is suffering the same fate !

What if regular exercise were as good as a stent for stable angina?


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Exercise  stress test ( Also called treadmill test ) is an important investigation  not only in patients  with suspected  CAD  but also in  established CAD . In the former  group ,  it helps us to exclude CAD in patients with chest  pain and in the later group ,  it helps us to assess  functional capacity , risk stratification and to detect any  additional ( New or residual ) ischemia.

Stress test being a physiological test , has a huge  advantage of assessing the adequacy of myocardial blood flow without even  knowing the coronary anatomy , while Coronary angiogram (CAG)   has a zero physiological value* in spite of   excellent assessment of the coronary anatomy !

It is an irony , in the assessment of angina we are expected to assess the physiological adequacy of myocardial blood flow ,  we have kept coronary angiogram as a gold standard  over and above the much  neglected  physiological stress test.

Of course, the limitation of stress test is that ,  it has only 75%  specificity(  to rule out CAD ) and about 80% sensitivity (To detect CAD ) .In simple terms  stress test is likely to miss  20% times to miss a CAD  in patients with CAD  and 25% of times falsely diagnose CAD  in patients without CAD.

In the above statistics  ,  coronary angiogram was considered   gold standard . The problem with this data is that , CAG is not the real gold standard ,but it was  nominated  as a gold standard . We now know normal coronary angiogram is not equivalent  to  normal coronary arteries and vice versa.

While both test have limitations , it is logical to believe CAG has an edge over stress test since it visualises the anatomy. But ,  once an obstruction is demonstrated by CAG, stress test scores over in assessing the physiological impact of the lesion.

Is a 70% LAD lesion significant or not ?

Stress test will give vital information to answer this question.If this patient performs 10-12Met exercise without symptoms it means , the obstruction is not impeding the flow even during stress. He may do well with medical therapy.

What does a positive stress *mean for the patient and for the physician ?

(* A false positive EST in LVH, anemia, baseline ST shifts are included in discussion )
  • A positive stress test  with or without angina at low workload <5 METS  indicates very significant obstructive CAD either in left main , or proximal LAD/LCX. They should get immediate CAG.
  • A positive stress test at load  5-10METS  is again significant and patients should get early CAG
  • A positive stress test with angina at good work load >10-12 mets  would indicate insignificant or minimally obstructive  CAD.
  • A positive stress test at  the peak of exercise  at good work load > 10-12METS without angina could indicate a false positive or very minimal CAD.

For the physician , the proper way  of interpretation  should be , the fact that a person performs 10-12  METS  indicate the myoacardial blood flow  would  be  more than adequate in most life situations. Knowing the coronary anatomy serves no purpose here, as no revascularisation will be attempted even if he is going to have a significant CAD ( Which again , is also highly unlikely ) .He should be managed with appropriate lifestyle (Diet, activity, relaxation )  anti anginal drugs,  aspirin , good lipid control and plaque stabilisation with statins .

Can a  patient with critical left main  or proximal LAD  perform >10METS in exercise stress test ?

No , large clinical experience (Also refered to Class C evidence  by ACC/AHA!) indicate no patient with critical  left main or equivalent disease  can perform 10 METS  excercise

While  ,  EST may be less hyped investigation, but it is the  only  noninvasive test , ( that too , simple and  cheap ) that can rule out * a significant left main  or equivalent almost   100%  correctly .

Now that,   the results of COURAGE  and BARI 2D have clearly indicated medical therapy is best form of management  in chronic  CAD , ( except in severe obstructive CAD in vital locations)  a  positive EST  at > 10-12Mets  , has absolutely no indication* to for doing a CAG.

*Some would advocate a policy of  doing a  CAG as a baseline investigation in all patients with positive EST  to know the coronary anatomy and will not proceed onto revascularisation if there is insignificant lesions.

Further ,  real life experience has taught us , routine  CAG in these patients

  1. Increases patient anxiety as he is given a report with a diagram of obstructed heart vessels
  2. Leads to multiple cardiac consultations
  3. Divergence of opinions
  4. Finally end up in  the likely hood of a inappropriate  revascularisation for a  insignificant distal CAD.

Final message

Every patient,  who has positive stress test  , ( Please note , it could  even be  true positive  )  need not undergo CAG .  Most  interventional cardiologists could  feel  otherwise , but one should also  remember ,  There is one  more role  for the interventional cardiologist ie  , to intervene when inappropriate interventions are done to their patients.


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