Background: Myocardial (re)infarction (MI), a common trial end point, can be difficult to identify because of inconclusive signs and symptoms. We examined disagreement between investigator and clinical events committee (CEC) reporting of MIs in an international, randomized trial.
Methods: The primary end point of the PARAGON-B trial was a 30-day composite of death, MI (CEC adjudicated), or ischemia-driven intervention. If CEC and investigator determinations of MI differed, we sent investigators event summaries and rationales for CEC decisions and asked whether they now agreed with the CEC assessment. If they still disagreed, they were to provide a rationale and supporting data. Such cases were reviewed, and a final decision was made.
Results: Overall, 1736 of 5225 (33%) patients had suspected MIs; the CEC adjudicated 483 of 1736 (28%) as MIs. In 404 patients (23%), investigator and CEC assessments of MI differed; 270 MIs were identified by the CEC but not investigators, and 134 were identified by investigators but not the CEC. Most disagreements concerned periprocedural MIs, but some reflected clinical ischemia and enzyme elevations. Letters for 382 disagreements were sent and returned by investigators, and investigators came to agree with CEC assessments in 307 cases (80%). For the other 75 cases (20%), after review the investigators' assessments were confirmed in 10 cases, and the original CEC decisions were supported in the other 65 cases.
Conclusions: Investigators misreport MI end points, but most later agree with CEC assessments. These data support standard, independent adjudication of suspected MIs for accurate reporting, which may affect evaluations of therapies, sample-size calculations, and event-rate comparisons across trials.