Describing Activity in Primary Percutaneous Coronary Intervention: An Exploration of Denominators. From the HEAT Trial - A Systematic Evaluation of PPCI Activations in Liverpool, Explaining Denominators (HEAT-SEALED).

The provision of primary percutaneous coronary intervention (PPCI) in the emergency management of ST-elevation myocardial infarction (STEMI) is expensive and resource intensive. Accurate data collection is essential not only for outcomes analysis but also to characterize activity and performance for regions, centers, and operators. Inconsistency in the use of denominators currently creates problems in data interpretation.To establish a system of denominator groupings, seeking to better describe the range of clinical activity resulting from an unselected series of PPCI activations.The HEAT-SEALED pathway designates a key denominator group (n1-n9) to each phase of PPCI activity and identifies a final "destination category" for each patient leaving the pathway. HEAT-PPCI (How Effective are Antithrombotic Therapies in Primary Percutaneous Coronary Intervention) is a true "all-comers" trial and provides an ideal platform to collect data for prospective validation of the pathway. We report data from all PPCI activation events for the HEAT-PPCI trial.Our findings demonstrate important differences between the sizes of key PPCI denominator groups and hence the potential for variation in reported outcomes depending on the denominator category selected. The main figures are: all activations (n1 = 2490); all suspected MI cases (n4 = 1940; 77.91%); patients in whom angiography was performed (n5 = 1904; 76.46%); cases in which diagnosis was confirmed with a probable culprit lesion (n6 = 1657; 66.54%), and cases with complete PCI success (n9 = 1441; 57.87%).The HEAT-SEALED pathway offers a practical and comprehensive solution to the problem of describing denominators in STEMI and PPCI. Routine application would facilitate a more consistent and precise description of activity and outcome.