Dr.S.Venkatesan MD

Nothing in this world is black and white. In fact,  most events are in between . The irony is , our brain  always wants to view  things in two distinct entities !

• Success or failure
• Beautiful or ugly
• Good or bad
• Win or lose,
• Rich and poor etc . . . etc

So it is no  surprise !  cardiologists  also travel in the same boat !

They classified  the events after thrombolysis   into two dogmatic categories . Successful  thrombolysis or failed thrombolysis   . . .  as if no other event  can occur in between .

Traditionally 50% regression of ST segment is called successful .   What  about 30%  and 40 % ST regression ?

Further , there is an important caveat  in the timing,  as we  traditionally assess ,  90 minutes of thrombolysis .

Consider the following  situation  :

1. Thrombolysis  is failed at 90 minutes, but  succeeds  at 120/180  minutes ?
2. Is 50 % ST regression at 180 minutes is as bad  or as good as 25 % regression at 90 minutes ?
3. How to label a patient who  is extremely comfortable in spite of ECG criteria of failed thrombolysis ?(Surprisingly this situation is fairly common !)

So, without finding answers to some critical questions , we have defined the success  of thrombolysis with  half baked data .

This is exactly , is the reason we  are unable to do a  valid  study on failed thrombolysis, rescue PCI etc .  We know the results of rescue PCI  ,  always  been  contradictory to the general logic !

It is estimated a substantial number of  STEMI patients following   thrombolysis   fall into a category of partially successful thrombolysis implying partial restoration of blood flow and salvage. The correct definition for  successful thrombolysis and reperfusion should be at the myocardial mass level , and  not at the level of coronary artery.The ECG  is the best available indicator.

Implication for having a  poor definition  of  failed thrombolysis

It is not a rare sight to wheel  in , a patient to a cath lab  with label of failed thrombolysis dangling in his neck  who is clinically  stable  (Has a less than required 50%  ST regression , but a definite, favorable trend with a 30 % ST regression  at 90 minutes  )

How many cardiologists will be willing to abort a CAG/PCI  , as a repeat ECG just  before puncturing  in the  cath lab reveals    successful  thrombolysis ? (little  delayed though !)

If only we have better methods to risk stratify patients following thrombolysis , we can avoid

• Huge costs incurred
• Expected and unexpected hazards of doing an emergency  intervention in an adequately salvaged STEMI
• Hundreds of cardiology man hours can be saved  for better purposes .

Final message

Classifying thrombolyis into  success  or  failure  is a  skewed  way of looking  at this important  issue .

It is an irony ,  cardiologists often  triage LV dysfunction , valve disease , cardiac failure  etc  into 4  grades (  minimal  , mild , moderate or severe  ) . It is  still a mystery ,  why thrombolysis  is never graded  like that ,  and it is always considered as  all or none phenomenon !

There is a substantial number of patients  with partially successful ( or shall we call partially failed !) thrombolyis  .This group must be given adequate attention or inattention  . There  is a urgent need for a through review of how we look at  the post thrombolysis status  . It is better to use the newer imaging modalities like PET/MRI more  liberally to identify  exact sub group  of failed thrombolysis who will benefit form revascularisation .