International comparisons of the management of patients with non-ST segment elevation acute myocardial infarction in the United Kingdom, Sweden, and the United States: The MINAP/NICOR, SWEDEHEART/RIKS-HIA, and ACTION Registry-GWTG/NCDR registries

Objectives: To compare management of patients with acute non-ST segment elevation myocardial infarction (NSTEMI) in three developed countries with national ongoing registries.

Background: Results from clinical trials suggest significant variation in care across the world. However, international comparisons in "real world" registries are limited.

Methods: We compared the use of in-hospital procedures and discharge medications for patients admitted with NSTEMI from 2007 to 2010 using the unselective MINAP/NICOR [England and Wales (UK); n=137,009], the unselective SWEDEHEART/RIKS-HIA (Sweden; n=45,069), and the selective ACTION Registry-GWTG/NCDR [United States (US); n=147,438] clinical registries.

Results: Patients enrolled among the three registries were generally similar except those in the US who were younger but had higher rates of smoking, diabetes, hypertension, prior heart failure, and prior MI than in Sweden or in UK. Angiography and percutaneous coronary intervention (PCI) were performed more often in the US (76% and 44%) and Sweden (65% and 42%) relative to the UK (32% and 22%). Discharge betablockers were also prescribed more often in the US (89%) and Sweden (89%) than in the UK (76%). In contrast, discharge statins, angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB), and dual antiplatelet agents (among those not receiving PCI) were higher in the UK (92%, 79%, and 71%) than in the US (85%, 65%, 41%) and Sweden (81%, 69%, and 49%).

Conclusions: The care for patients with NSTEMI differed substantially among the three countries. These differences in care among countries provide an opportunity for future comparative effectiveness research as well as identify opportunities for global quality improvement.