Primary PCI has become the standard of care for acute STEMI in all those eligible patients. Apart from the individual & institutional expertise ,the key to success lies in expediting the symptom to balloon time to less than an hour.
Even though STEMI is characterized by acute total obstruction , it is also a fact during this critical time window , a less recognised positive phenomenon takes place within the ill fated coronary artery. Intrinsic fibrinolytic activity gets activiated and begins to take on the thrombus head on .It should be recalled this is the earliest intervention in STEMI by natural forces , with zero time window . The power of this natural lytic process has never been easy to predict and quantiate . But we have often realised such a phenomenon do occur often and is referred by various terminologies like spontaneuous thrombolyis, aboted MI etc .The exact incidence is not estimated .In this era of primary PCI we have found a new opportunity to confirm this concept.
It has been observed during primary PCI , an occasional patient may have either a totally patent IRA or a minimal & insignificant lesion like luminal irregularity .This has subsequently led on to cancellation of the procedure .We report our experience with two patients with this particular situation .One patient with IWMI with a time window of 6hours had a totally patent RCA. Even , the luminal irregularities were difficult to locate .The other patient had anterior MI with ongoing ischemic pain.He was taken up for primary PCI.The initial angiogram showed a total mid LAD obstruction . As soon as the guidewire reached the thrombotic lesion the artery opened up wth a TIMI 3 flow .There was no residual lesion or thrombus noted. Both of the above patients were young , smokers . 2b 3a antagonists were not administered. We infered, both had thrombotic STEMI and presumed to had either spontaneous reperfusion , or reperfusion assisted by dye injection & guidewire manipulation. They were shifted out of cath lab with a new code of aborted primary PCI and were discharged with normal LV function .It need to be realised here, a distinction must me made between aborted PCI and abandoned or failed primary PCI as the later connote a negative outcome. The causes for abandoning primary PCI are due to complex lesions like bifurcation /Trifurcation lesions , triple vessel disease with difficulty in identifying culprit lesions.A Primary PCI is considered failed when the IRA patency is not accomplished or failure to sustain myocardial flow inspite of IRA patency (No-Reflow) . These patients may end up in CABG or occasionally fall back on thrombolysis which was considered a inferior modality just few hours earlier !
. We conclude , in the management of STEMI , primary PCI once contemplated need not always reach it’s logical conclusion. There are situations it can get aborted or abandoned at various levels . Aborted primary PCI due to spontaneous lysis though uncommon , can be a therapeutically and financially rewarding concept for the patient and physician .