It's not very often I read an article and decide to I'd like to incorporate it into my practice. EMCrit covered this last month, but I reserved judgement until I had a chance to read the primary literature for myself.
This is the MOPETT trial – half-dose (?"safe dose") tPA for "moderate" pulmonary embolism. We already know what to do for "massive" PE – full-dose thrombolytics when not otherwise contraindicated. However, the data for full-dose thrombolytics in "submassive" PE is less conclusive.
These authors enrolled relatively ill PE patients – tachypneic, hypoxic, tachycardic patients with >70% thrombotic occlusion of lobar or main pulmonary arteries – but did not apply regularly applied measures of "submassive" – RV dysfunction, elevated troponins, elevated BNP. Their primary outcome was long-term development of pulmonary hypertension, with mortality and bleeding as their secondary outcomes. They dosed tPA at 50mg, rather than 100mg – 10mg bolus and 40mg infusion.
Their two cohorts were rather well matched. Outcomes favored the thrombolysis group, with 16% subsequent pulmonary hypertension compared with 57% in the control group. Mortality, recurrent pulmonary embolism, and bleeding complications were similar and at rates too low to detect a difference given the power of the study.
I'd like to start doing this. I wish they published the troponin/BNP/RV dysfunction rates in the two cohorts to provide better context with the other submassive literature. I also would have preferred to see this study registered with clinicaltrials.gov. But, in a nice change, none of the authors declare any conflicts of interest!
"Moderate Pulmonary Embolism Treated With Thrombolysis
(from the “MOPETT” Trial)"