Defining Unavoidable Delays in Primary Percutaneous Coronary Intervention: Discordance Among Patients Excluded From National Cardiovascular Quality Registries

BACKGROUND The Centers for Medicaid and Medicare Services (CMS) and the National Cardiovascular Data Registry (NCDR) track primary percutaneous coronary intervention (PCI) performance in the form of door-to-balloon time. For quality assessment, exceptions are made for patients with "unavoidable delays" in both registries, yet it remains unclear how consistently such patients are identified. METHODS AND RESULTS All primary PCI patients at 3 Massachusetts hospitals (Brigham and Women's, Massachusetts General, and North Shore Medical Center) from 2009 to 2011 were evaluated for CMS inclusion/exclusion and NCDR nonsystems delay (NSD) status. We subsequently analyzed patient characteristics and outcomes based on these strata. Among 456 total patients, 128 (28%) were excluded from CMS reporting, whereas 56 (12%) were listed in the NCDR registry as having an NSD. Forty of 56 (71%) patients with NSD were also excluded from CMS reporting, whereas 312 of 400 (78%) patients reported without NSD were included in CMS reports. Between-registry agreement on patients with unavoidable delays was modest (κ=0.32). Among CMS-included patients without NSD, 94% received PCI within 90 minutes compared with 29% of CMS-excluded patients with NSD (P<0.001). Likewise, CMS-included patients without NSD had a 4-fold better 1-year mortality rate compared with CMS-excluded patients with NSD (P<0.001). CONCLUSIONS More than twice as many primary PCI patients are excluded from CMS quality analyses compared with NCDR. With the use of currently available cardiovascular quality registries, it is unclear how many patients truly require unavoidable delays during primary PCI. Patients with NSD had the worst outcomes regardless of CMS status.