Time-Trend Analysis Compares Primary PCI Outside Working Hours Versus In-Working Hours

June 8, 2015—M. Bilal Iqbal, MD, PhD, et al published findings from an observational study of more than 11,000 patients to determine whether primary percutaneous coronary intervention (PCI) performed outside working hours (OWH), when resources are limited, is associated with worse outcomes and whether outcomes have improved over time for the treatment of ST-segment elevation myocardial infarction (STEMI). The findings are available online ahead of print in Circulation: Cardiovascular Interventions.

The investigators concluded that in this study of unselected patients with STEMI, primary PCI during OWH versus in-working hours had comparable bleeding and mortality rates. Time-stratified analyses demonstrated a reduction in adjusted bleeding and mortality during OWH over time. This may reflect the improved service provision, but the increased adoption of transradial access during OWH may also be contributory, advised the investigators.

As summarized in Circulation: Cardiovascular Interventions, the investigators analyzed 11,466 patients undergoing PPCI between 2004 and 2011 at all eight tertiary cardiac centers in London, United Kingdom. Working hours were defined as 9 AM to 5 PM, Monday to Friday. The investigators analyzed in-hospital bleeding and all-cause mortality ≤ 3 years, comparing OWH versus in-working hours.

A total of 7,494 patients (65.3%) were treated during OWH. Multivariable analyses demonstrated that primary PCI during OWH was not a predictor for bleeding or 3-year mortality. This was confirmed in propensity-matched analyses. Time-stratified analyses demonstrated that primary PCI during OWH was a predictor for bleeding and 3-year mortality during 2005 to 2008, but this association was lost during 2009 to 2011. During 2005 to 2008, transradial access was predominantly used during in-working hours, and PPCI during OWH was predictive of reduced transradial access use, but this association was lost during 2009 to 2011, reported the investigators.