Correlation of infarct size with invasive hemodynamics in patients with ST-elevation myocardial infarction.

Objectives: To identify invasive hemodynamic parameters that correlate with infarction size in patients with ST-elevation myocardial infarction (STEMI).

Background: Invasive hemodynamics obtained during primary percutaneous coronary intervention (PPCI) are predictive of mortality in STEMI, but which parameters correlate best with the size of the infarction are unknown.

Methods: This is a single-center study of 405 adult patients with STEMI who had left ventricular end-diastolic pressure (LVEDP) measured during PPCI. Size of infarction was estimated by peak troponin I level and ejection fraction (LVEF) determined by echocardiography.

Results: The average (±SD) age was 61 ± 14 years, TIMI STEMI risk score was 3.5 ± 2.7 and Grace score was 157 ± 42. Hemodynamic parameters that correlated best with EF were LVEDP (r = -0.40), PP (r = 0.24), and SBP/LVEDP ratio (r = 0.22) and with peak troponin were SBP/LVEDP ratio (r = -0.41), LVEDP (r = 0.31), and PP (r = -0.29). SBP/LVEDP (AUC = 0.76) and SBP (AUC = 0.77) had a stronger association with in-hospital mortality than did LVEDP (AUC = 0.66) or PP (AUC = 0.64). Door-to-balloon time did not affect the correlations between hemodynamic parameters and infarct size.

Conclusions: In this sample of 405 patients undergoing PPCI, SBP/LVEDP ratio had the strongest correlation with peak troponin levels and LVEDP with EF, whereas SBP/LVEDP and SBP had a strong association with in-hospital mortality. These results suggest that measurement of LVEDP as well as SBP may help risk stratify patients during PPCI.