To assess the impact of tPA on cerebral cavernous malformations (CCM), Erdur et al. retrospectively assessed the frequency of CCM in 967 consecutive stroke patients who were treated with iv tPA. The study endpoint included symptomatic or parenchymal intracerebral hemorrhage (SICH and PH).
In their analysis, they only included the 350 patients who obtained a brain MRI prior to receiving tPA. They revealed that the frequency of coexistent CCM in their population to be 2.6%. The data demonstrated a non-significant trend towards both SICH (11.1% vs 3.2%) and PH (22.2 vs 7.9%), when comparing CCM to non-CCM tPA patients.
This study is an eye opener. The current tPA guidelines do not include CCM as an exclusion criteria. This study however showed a non-significant trend towards bleeding complication. Albeit it, the bleeding complication occurred in 2 out of 9 CCM patients, one of which bled into an actively bleeding CCM, and the other developed hemorrhagic conversion nearby a dormant CCM. However, on careful review of the paper, 11 other patients with CCM were identified on post-tPA. They did not have bleeding complications. They were excluded because CCM were identified on MRI post-tPA. In this group the CMM were not involved in driving the decision to give tPA. I argue that this group should have been the test population because they were not subject to selection bias by conservative physicians who are otherwise deterred by presence of CCM. Irrespective of my opinion, should these 11 patients be included in the final calculations, the frequency of SICH and PH would be 1/20 (5%) and 2/20 (10%), respectively. This bleeding rate would be similar to the non-CCM group, making CCM a trivial variable in tPA decision making. I am confident that this study will drive other large medical centers to publish their own CCM experience, and a subsequent meta-analysis will ultimately direct our management and future guidelines. In the meantime, would you tPA a patient with a known CCM? I would have to say, it depends!