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Posts Tagged ‘primary pci’

The age old  statistics , 30 % of deaths following STEMI happen even before patients reach the hospital may still be true. But ,there is an untold story that happen regularly in the rehabilitation phase .Its ironical many  apparently stabilised STEMI patients still lose their life just before they get discharged or within 30 days .More often than not this happens in the toilet when they strain for defecation. At least a dozen deaths I have witnessed in the last few years. Of course we have resuscitated many near deaths as well.

What exactly happens to these ill-fated patients inside the toilet  ?

Straining is often an isometric exercise and prolonged strain ends up in   valsalva maneuver , a prolonged valsalva strain realistically shuts both vena cava due to raised intrathoracic  pressure .Vena caval shutdown is equivalent to asystole and imagine the chaos in the  delicately recannalised LAD when the coronary perfusion pressure nose dives (Even the  stented segment in IRA is vulnerable as distal flow restoration may take time   !)

The sudden systemic hypotension leads to  fall in coronary arterial pressure proximal  to the lesion. The normal physiological response to proximal fall would be corresponding distal fall maintaining the flow gradient . If the microvascular bed is damaged( loss of capacity to vasodilate ) this distal fall may not happen promptly .So its acute standstill of flow  across IRA ( or even Non IRA if it has a lesion )  triggering events that rapidly destabilise  unless intervened.

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hemodynamics of ffr lad valsalva 2

 

 

 

 

 

 

 

 

 

 

 

 

 

Other modes of sudden toilet deaths

*The opposite process , ie sudden spikes of blood pressure (In contrast to hypotension of  Valsalva strain ) can  occur as straining is equivalent to Isometric exercise which increase afterload .This can either cause LV failure, another episode of ACS, myocardial stretching, even tear it and result in mechanical complication.

  1. Acute LVF triggered by spikes of BP /new onset ischemic MR.
  2. Free wall rupture and tamponade.
  3. Emboli getting dislodged from LV during strain

How to anticipate and prevent these  deaths ?

  • All complicated STEMI patients should have special rehabilitation program.
  • A simple rule could be patients with persistent ST elevation with  are prone for further events.They should be flagged. (Stented / TIMI flows matters very little !)
  • Restrict all vigorous activity for minimum of one to two weeks ( I am not a believer of pre-discharge stress test even in uncomplicated MI  )
  • Use laxatives adequately.
  • Western toilets may have an hemodynamic advantage. Indian closets that require squatting which increase the venous return , ultimately it compromises coronary hemodynamics more. We don’t understand as yet ,what will happen if one perfoms a valsalva  and  squatting simultaneously.(Which will prevail over the other ?)
  • Finally toilet shouldn’t  be locked during rehabilitation for safety purposes.
  • All post STEMI pateints should have registered with emergency contact and alert service ready.

Has primary PCI has reduced the sudden deaths  in Post MI period in current era ?

I’m afraid , I can’t say a dogmatic yes . May be ,to a certain extent , However,  it has created a new subset of perfectly  stented still prone for ACS.A physiologically or pharmacologically  recannlised IRA generally heals by themself. A Stented IRA  hands over  the responsiblity of healing the injured IRA to us  .Ofcourse ,we try to do it  with lot of difficulty  .(Different versions of  confused DAPT  regimens !)

Final message 

Please note , “discharge to 30 day mortality” following STEMI   which is  upto 2 %  .It is the most neglected  and  mismanaged phase in coronary care .Toilets are definitely not a benign place for them and all the good work done by you in cath lab and CCU can be nullified in few Innocuous looking seconds !

Postample 

Is Toilet room death amounts to  negligence / mis-management  inside hospital ?

May be there is a reason for this argument. When to ambulate in complicated STEMI is a big question. ? Though we have guidelines some of the patients are reluctant to use assisted service.

I think its a calculated risk , and  there is trade off between the benefits of early ambulation and potential exertion related risk.

One such argument by a cardiologist in a medicolegal situation goes like this. “I thought my patient’s heart  is stable enough to use toilet , it misfired , hence it is just an error of  judgment. I can’t be faulted.  Though this argument appear logical , many times it can’t hold water in court of law !”

Reference

1.Siebes M, Chamuleau SA, Meuwissen M,   Influence of hemodynamic conditions on fractional flow reserve: parametric analysis of underlying model Am J Physiol Heart Circ Physiol. 2002 Oct;283(4):H1462-70

Further reading

Cardiac rehabilitation NICE guidelines  : Myocardial infarction: cardiac rehabilitation and prevention of further cardiovascular disease 2013

 

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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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Less than a century ago an easy chair  was enough to manage this most important medical emergency of mankind. Of course, at that time mortality of STEMI was estimated to be around 30%.We have since pushed the in-hospital death rate down to less than 10 %  and its around 5-8% currently.(*The lifeless chairs were able to save 70 lives is a different story!)

Heparin , thrombolytic agents, critical coronary care has helped us to achieve this , of course It must be admitted primary PCI also played a small role (at best 1 % ) in our fight against this number one killer.

Now, why not combine  both lysis and PCI ?

The concept of PIA (Pharmaco Invasive approach) came into vogue  primarily for two reasons.

1.If thrombolysis and  pPCI are powerful strategies by individual merits why not combine both and achieve double the benefit ?

2. Since pPCI is going to be a logistical nightmare in most points of care and we can’t afford to lose time . So, let us lyse first and consider PCI later !

Unfortunately medical science is not math .One plus one in medicine is rarely two !

Though , it looks attractive , Pharmaco invasive approach  has its own troubles.Fortunately , most of them are man-made, few are beyond our knowledge though.

Following general rules  may help us

  • STEMI  should ideally managed by early thrombolysis (or PCI) in all deserving patients.
  • Don’t wait for PCI if you think , there will be delay or reduced expertise and poor track record of the center in this modality.
  • Pharmaco invasive  therapy is not a default in all STEMI .Do good quality , monitored  lysis , (Not necessarily new generation thrombolytic .(I prefer one hour sustained thrombolytic regimen , not the hit or miss bolus) .As a learned cardiologist we need to assess individual patients according to the type and risk of MI.Its not wise to blindly follow the guidelines ,because these guidelines , though based on evidence never answers a query in a single patient perspective !

The key “branch points”  in decision making  after lysis

  • Invasive strategy  should begin within one hour if the patient has failed  thrombolysis and has developed any mechanical issues.( Mind you, LVF requires good medical stabilization .Rushing  such patients to cath lab without application of mind can be disastrous )
  • If the Initial  lysis is excellent and the patient is asymptomatic  one need not proceed with invasive limb at all.(A significant chunk of apparently failed lysis by ECG are asymptomatic and comfortable , these are patients require delicate assessment regarding further intervention. )
  • If the MI is large and the clinical  stability is “not confirmed” one may  proceed urgently within 24 h.
  • In any case there is no role for invasive approach after 24 hours* Unless fresh ischemia  suspected to come from IRA or  non IRA.
  • Having  said that, there are many centers that do a diagnostic  angiogram alone just prior to discharge  (48-72h) for risk stratification and then take a genuine call for a possible PCI or  CABG. In my opinion it appears a sensible strategy , though a non invasive stress  test pre/post discharge can even avoid that  coronary angiogram !

One issue with Rescue PIA

Though by current definition  PIA is to be done  3-24 hours , don’t wait for the 4th hour if you have recognized a failed thrombolysis earlier than three hours.( Ofcourse , as the gap between P and I gets too narrowed it may  carry some adverse  effects witnessed in routine facilitated PCI -Refer FINESSE study ) Similarly,there need not be a blanket ban on PCI beyond 24 hours if residual ischemia is active.

Final message

PIA is a dynamic  coronary  re -perfusion strategy . Nothing is fixed in science. . The optimal gap between Pharmaco and invasive strategy  can be anywhere between  1 hour to “Infinitely deferred” depending upon individual risk perception and wisdom of the treating cardiologist.

 

 

 

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Scientific cardiology has forced us to believe ACS management must be catheter based and all others are inferior  and  those who pursue the later , carry a risk of  being labelled as unethical in near future. However ,experienced cardiologists will know  where the truth lies.

Now,in the interventional cardiology board rooms  there is a big  debate going on regarding the value of early total revascualrisation in STEMI with multivessel CAD.Suddenly , every lesion looks suspect ( Ex,current or future culprit ! ) and all stentable lesion are stented  either in an emergency or semi emergency fashion (The new age post PCI dialogue goes something like this “I have tackled one culprit , other one seems to hide in LAD ,  we will arrest it  next 48 hours or so* ? ( This is the concept of  deferred or staged  non-IRA stenting )

*Ironically it brings   one more dubious therapeutic time window in ACS !

ptca ira non ira multivesssel pci

The recent  studies like  PRAMI, PRIMULTY ,CvLPRIT are trying to find out an answer to this issue  and suggest acute multivessel PCI may be  good strategy. Some of them advocate a FFR guided non IRA intervention , knowing fully well micro-circulatory bed is completely altered by the index acute thrombotic event.( Mind you , for FFR,  we need to induce maximum hyperemia with Adenosine in a highly varying local autonomic milleu within the thrombus clogged capillary network)

Final message ( Intentionally biased !)

Till we learn or unlearn  it is vital to go with conventional wisdom.Don’t pursue a random hunt for coronary culprits in acute phase of  STEMI.Many of them are innocents and likely to suffer in cross fire.Tender coronary arteries need some rest,peace and time to heal thyself  . Just keep away , they will definitely say big  thanks with folded hands !

Reference

1.Gershlick AH, Khan J, Kelly DJ, et al. Randomized Trial of Complete Versus Lesion-Only Revascularization in Patients Undergoing Primary Percutaneous Coronary Intervention for STEMI and Multivessel Disease: The CvLPRIT Trial. J Am Coll Cardiol. 2015;65(10):963-972.

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When a culprit thrombus keep the  myocardium as hostage . . . don’t storm the coronary artery  indiscriminately   !

When a single gun men  keeps 100 innocent people as hostages , threatening their  lives, rescue mission should start .No can can afford to wait. But, without knowing  the  culprit’s true nature the process of rescue mission is always going to be tricky .There are so many instances Newton’s third law  was reversed , when reactions  evoke more chaos  than the index action.

In the recent world terrorist events ,  the  rescue missions  were so delicate and  it was very  unfortunate we  lost  many   innocent hostages !  The reasoning is ,there  is no way we can avoid these. I wonder is it really true ? !

rescue missionNot all culprit lesions  are true ones.They simply threaten  our myocardium with  thrombus and plaques  in various forms .Don’t show aggression to pseudo threats  you may  ultimately end up with more damage.(What I call as crazy culprits!)

(  Read here , why unstable angina even though thrombus is sitting right inside the coronary artery attempting to lyse it causes more  damage !)

After thought

Iam sure ,bulk of  the Interventionists wouldn’t agree with this thought . They would decry , watching a person  silently when the myocardium  is on  fire is a serious crime !

But . . . we  need to  remember the process of extinguishing  the fire  with some more fire arms is a delicate game played in undefined  philosophical turf.

The only way to introspect  such events in life is , to accept any eventuality    arising out of “not pursuing”  a  presumed rescue mission with vigor. No need to be guilty about that,after all , it can be a myth !

Modern human cognition , growing with a staple  scientific  feed  on a 24/7  basis  is  unlikely to realise , restraint can be an effective tool  even in critical moments !

Oh,is all that I have  scribbled so far  is just a repetition  of 1000 year concept of  “Primum non nocere”

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Interventional cardiologist extraordinary  cath lab tips invasive great

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Multivessel PCI during acute STEMI is forbidden except in cardiogenic  shock . (or in some very unstable patients without cardiogenic shock)

The reason

  • During acute MI   hemodynamics  are precariously balanced.We do not know yet how  emergency multivessel plasty alters this .
  • Our  initial aim should be   confined to myocardial salvage in the IRA . Total myocardial revascularization is niether  the  priority nor its desirable.
  • The more  time  you spend  within the inflamed coronary artery , more its  hazardous.
  • Multiple stenting  is prone for thrombus   and  migration  into side branch .
  • Stent opposition is sub optimal in many thrombus infested lesions.

Still  . . .  in real world it is extremely difficult to curtail the urge to stent  all eligible lesion during primary PCI !

multivessel angioplasy during stemi

How to avoid it ? 

If the patient is poor or the insurance limit is low , the issue  of multi vessel stenting does not arise at all  !

Always  ignore  complex  non IRA lesions  during primary  PCI. Be happy if a non IRA has a bifurcation lesion !

Still , some lovely looking lesions in non IRA  would be  tempting  and inviting .  Indulge at your own risk !

* Please remember if  the proximal  LAD  has a non IRA lesion , it may be sensible to attempt  simultaneous revascularisation even if the patient is stable !

Other unrealistic advice

  • Keep the professional fee and other benefits   fixed whether  we do a single or multiple   vessel stenting (Realise  . . .  surgeons do not charge more for a  4  vessel by-pass graft  than a single  ! )
  • Keep the current AHA/ACC/ESC guidelines pasted right next to the fluroscopy monitor .
  • Ask your subordinates to repeatedly caution   you  about the possible  excesses and ask them to wave a red flag !
  • You may  empower the   senior staff nurse   with a veto power  to shut off the cath lab once IRA plasty is  completed and the patient  is stable.
  • In extreme  situations , keep a cath  marshal ready to manually evacuate  the primary operator  from cath lab !

Reference

multivessel angioplasty during stemi

ACC GUIDELINES FOR STEMI 2013

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