Background: The utility of longitudinal strain (LS) as an index for detecting myocardial ischemia in patients presenting to Emergency Rooms (ER) with chest pain (CP) was tested in the 2DSPER study. The current anaysis was aimed at identifying compounding factors that may affect LS.
Methods: Two-dimensional strain (2DS) analysis was available for 606 patients (mean age 58±9 y, 70% males) presenting to 11 Israeli ER with CP and suspected acute coronary syndrome (ACS) but without diagnostic ECGs or troponin elevations. An echocardiogram was performed within 24 hours of CP and analyzed in a core lab. A final diagnosis of ACS was made in 74 patients. Two LS indexes were tested: 1) Global strain (GS)= mean of segmental peak systolic strain (PSS). 2) PSS20%= histograms of PSS were generated and the value identifying the 20% worst PSS values was determined. Cutoff points for ACS were: GS>-20% and LV20%>-17%. Variables tested were: coronary disease risk factors, gender, age, body mass index (BMI), heart rate (HR), systolic blood pressure (SBP) and a diagnosis of ACS.
Results: Factors independently associated with PSS20% were male gender (OR 2.4, CI 1.6-3.7, p<0.0001), BMI (OR 1.1, CI 1.04-1.15, p=0.0002), HR (OR 1.03, CI 1.01-1.05, p=0.001) and SBP (OR 1.01, CI 1.001-1.02, p<0.04). ACS was not independently associated with PSS20%. Factors independently associated with GS were male gender (OR 1.9, CI 1.3-2.8, p=0.001), BMI (OR 1.06, CI 1.02-1.2, p=0.007), current smoking (OR 1.7, CI 1. 1-2. 5, p=0.01) and ACS (OR 2.0, CI 1.05-3.8, p=0.03),
Conclusions: In this large multicenter prospective study, male gender, BMI, HR, SBP and smoking significantly affected LS parameters. These findings may partially explain the failure of LS to predict ACS.
