Need to Clarify Thrombolysis In Myocardial Ischemia (TIMI) Scale Scoring Method in the Penumbra Pivotal Stroke Trial

To the Editor:We congratulate the Penumbra Investigators on the successful completion of the Penumbra Pivotal Stroke Trial.1 The addition of the Penumbra System to the therapeutic armamentarium is an important advance in acute stroke care.A major defect of the report is the investigators do not specify how they measured the primary trial outcome, angiographic revascularization. They state without further elaboration that the core laboratory used the Thrombolysis In Myocardial Ischemia (TIMI) scale to assess revascularization. However, the TIMI scale was developed for the myocardial circulation and cannot be applied in the more complex cervicocephalic arterial tree without the creation of additional operational rules. A recent review found no fewer than 7 different operationalized versions of the TIMI scale being used across different stroke trials.2 The Stroke Therapy Academic Industry Roundtable (STAIR) has for this reason recommended abandonment of the TIMI in future cerebral revascularization clinical trials and use of one or more of the more transparent …