Why Decreased D2B Time Has Lowered Mortality in Individuals but Not at the Population Level

Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for ST-elevation myocardial infarction (STEMI), but time delays before the procedure hamper clinical outcomes. Although door-to-balloon time (D2B time) is predictive of in-hospital mortality, recent declines in average D2B time have not been associated with reduced mortality at the population level. Researchers in the U.S. retrospectively investigated this paradoxical finding by simultaneously assessing components of the association at the individual and population levels. The data were from the National Cardiovascular Data Registry CathPCI Registry and included 150,116 procedures for primary PCI for STEMI between 2005 and 2011 in 423 hospitals. The study…