Author + information
- Said Yama Fakhri,
- Mads Ersboll,
- Lars Kober,
- Christian Hassager,
- Rasmus Hesselfeldt,
- Jacob Steinmetz,
- Peter Clemmensen and
- Mikkel Schoos
Increased system delay (time from alarm call to balloon) is associated with adverse outcomes in ST elevation myocardial infarction (STEMI). In current guidelines, allocation to a reperfusion strategy is entirely based on anticipated time delay to primary percutaneous coronary intervention (pPCI). We hypothesized that an objective ‘electric’ ischemia time assessed in the pre-hospital electrocardiogram (pECG) would improve the impact of time delay in predicting myocardial function as assessed by left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS).
We included 262 patients with STEMI and pECG, and performed echocardiography with measurements of LVEF and GLS within 48 hours of admission. ECGs were scored according to the previously validated Anderson-Wilkins acuteness score (AW 1–4) and Sclarovsky-Birnbaum grading of ischemia (GI2 or GI3). Patients were categorized by the novel pre-hospital salvage score (PHSS): PHSS1 = AW<3 & GI3, PHSS2 = AW<3 & GI2, PHSS3 = AW>3 & GI2 and PHSS4 = AW>3 & GI3, and system delay was assessed by PHSS for the prediction of LVEF and GLS.
System delay correlated weakly with GLS (r = 0.133 p = 0.031) and LVEF (r = 0.152 p = 0.014), but not with infarct size estimated by peak TnT (r = 0.056 p = 0.366). Lower PHSS was significantly associated with impaired GLS [PHSS1 (n = 42, mean −11.8 SD ±3.5), PHSS2 (n = 110, −13.7 ±3.2), PHSS3 (n = 90, −13.8 ±3.6), PHSS4 (n = 20, −14.1 ±3.7) (p = 0.008)], increasing peak TnT [PHSS1 (8.3 ±6.6), PHSS2 (5.6 ±5.2), PHSS3 (5.0 ±4.0), PHSS4 (5.1 ±5.5) (p = 0.006)] and there was a non-significant trend with impaired LVEF across PHSS [PHSS1 (47.6 ±9.0), PHSS2 (48.8 ±9.1), PHSS3 (50.9 ±9.4), PHSS4 (52.7 ±13.1) (p = 0.104)].
After adjusting for age, sex, Killip class, LAD culprit and pre-procedural TIMI flow, system delay independently predicted GLS (p = 0.002) and LVEF (p = 0.005) in PHSS4, whereas no adjusted time dependency was found for GLS and LVEF in PHSS 1–3.
Quantitative ischemia assessment already in pECG identifies STEMI patients where time reduction to pPCI is crucial for myocardial salvage. This method could help to risk stratify patients and select the optimal immediate reperfusion strategy.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Pre-Hospital ECG and Transfer: Time Is Myocardium
Abstract Category: 1. Acute Coronary Syndromes: Clinical
Presentation Number: 1212-176
- 2013 American College of Cardiology Foundation