But what about the patient who has not collapsed, but shows signs of a struggling RV (raised Tn, strain on echo). Should they be thrombolysed?
The headline result is a difference in the primary outcome of 2.6% in the intervention group cv 5.6% in the control group (p=0.02). This difference was made up almost entirely of a difference in the rate of CV collapse, the study being underpowered for a mortality difference. In order to achieve this however, there was a worrying increase in adverse outcomes. Major extracranial bleeding occurred in 6.3% of the intervention group and 1.2% in the control arm (p<0.001). There was a 10x increased risk of haemorrhagic stroke in the intervention group (2% vs 0.2%). I will not be giving thrombolysis to intermediate PEs.
Other things that were interesting included:
Some of the PEs were 15 days old at randomisation - I suspect the clot would be organising by this point possibly making thrombolysis less effective. 72% of the patients had one of the risk factors identified in the paper, with previous PE being by far the most common. I wonder if a previous PE makes it more likely a subsequent PE will give RV strain through a degree of chronic RV impairment? The risk of death from a PE with cardiac strain is 3% - I would have guessed higher.
Finally, can someone please explain to me why the incidence of the two components of the primary composite outcome don't add up to the composite incidence? (e.g. in the placebo group 9 patients died, 25 had CV collapse, but only 28 had either or) - I'm sure I'm missing something or it's in the supplementary appendix.
Please leave a comment with any thoughts you might have.....