Page 33 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

evaluated for major events, defined as death from all causes, non-fatal reinfarction, repeat PCI, or coronary artery bypass grafting.
Data extraction 2 The sum of ST-segment elevations was measured manually 80 ms after the end
of the QRS complex (J-point) in leads I, aVL, and V1 through V6. Resolution of ST-segment elevation was expressed as a percentage of the initial ST-segment
elevation. Resolution of 70% was defined as indicative for good myocardial reperfusion.14 Collateral flow to the IRA was graded before PCI, according to Rentrop’s classification.15 The TIMI flow and myocardial blush were graded,7,10 and cTfc was measured off-line.9 The rate–pressure product was defined as the product of heart rate and systolic blood pressure at the end of the procedure. Doppler flow velocity spectra were analyzed off-line to determine the following parameters: diastolic APV, diastolic deceleration time with a cutoff value of 600 ms,11 average antegrade systolic flow velocity with a cutoff value of 6.5 cm/s,11 the calculated ratio of mean diastolic-to-systolic flow velocity and early systolic retrograde flow velocity defined as retrograde peak velocity ≥10 cm/s, and duration ≥60 ms as previously described.16
A 16-segment model was used to determine systolic LV function.17 All segments with a good delineation of the endocardium were scored: 1 = normal, 2 = hypokinesis, 3 = akinesis, 4 = dyskinesis. Global wall motion score index (WMI) was calculated by summation of the scores divided by the number of analyzed segments. Nine segments were used to calculate regional WMI: basal and mid-anteroseptal; mid-septal; apico-septal; apico-lateral; basal-, mid-, and apico-anterior; and apico-inferior—usually representing the perfusion territory of the left anterior descending [LAD] artery. Recovery of global and regional LV function was defined as the difference in global and, respectively, regional WMI before PCI and that at specific time points at follow-up.
Statistical analysis
The study cohort consisted of patients who had an uneventful follow-up with an analyzable six-month follow-up echocardiography. The primary end point was recovery of LV function at six months, as defined above. Variables are presented as percentage of number of patients. Continuous variables are expressed as mean ± SD. Normally distributed variables were tested by two-
Prediction of recovery of LV function
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