Clinical impact of D2B delays varies according to cause
MedWire News: The clinical impact of door-to-balloon (D2B) delays in the treatment of ST-segment-elevation infarction (STEMI) varies according to the cause, report US researchers.
The development of a regional STEMI system that includes the transfer of patients from non-percutaneous coronary intervention (PCI) centers could improve timely access to care, write Timothy Henry (Minneapolis Heart Institute Foundation, Minnesota) and colleagues in the journal Circulation.
Although D2B times have improved recently, fewer than half of STEMI patients undergo PCI within the American College of Cardiology (ACC) and American Heart Association's (AHA) recommended timeframe of 90 minutes, explain the authors. These delays can diminish the mortality benefit achieved with PCI.
Henry and team therefore investigated the cause and location of these delays, in order to determine how D2B times can be improved.
The observational study included 2034 patients who were transferred for primary PCI at a single center between March 2003 and December 2009.
Overall, 613 (30.4%) patients were treated in 90 min or less, and 1324 (65.7%) were treated within the European Society of Cardiology's recommended optimal timeframe of 120 min or less.
The team found that the occurrence of delays (>120 min) was highest at the referral hospital (64.0%), followed by the PCI center (15.7%), then mode of transport (12.6%).
At the referral hospital, the most common reasons for delay were awaiting transport to the referral hospital for more than 30 min after the patient's call (26.4%) and emergency department delays (defined as ECG/system activation >15 min after arrival; 14.3%).
The longest delays were due to diagnostic dilemmas (defined as atypical symptoms or diagnoses other than STEMI investigated; median 95.5 min) and initial nondiagnostic electrocardiogram (ECG; defined if subsequent ECG revealed STEMI; median 81 min).
Delays that were caused by cardiac arrest and/or cardiogenic shock led to the highest rate of inhospital mortality (30.6%). In contrast, nondiagnostic initial ECGs, which led to the longest delays in D2B time, did not affect mortality.
Significant variation in both the magnitude and clinical impact of delays also occurred during the transport and PCI center segments, write the authors.
They conclude: "These results have important implications for the design of regional STEMI systems, inclusion of transferred STEMI patients in core measures, and potentially the current AHA/ACC guidelines."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Piriya Mahendra