What is the Best ST-Segment Recovery Parameter to Predict Clinical Outcome and Myocardial Infarct Size? Amplitude, Speed, and Completeness of ST-segment Recovery after Primary Percutaneous Coronary Intervention for ST-segment Elevation Myocardial Infarction

Abstract Aims ST-segment recovery (STR) is a strong mechanistic correlate of infarct size (IS) and outcome in ST-segment elevation myocardial infarction (STEMI). Characterizing measures of speed, amplitude, and completeness of STR may extend the use of this noninvasive biomarker. Methods and Results Core laboratory continuous 24-h 12-lead Holter ECG monitoring, IS by single-photon emission computed tomography (SPECT), and 30-day mortality of 2 clinical trials of primary percutaneous coronary intervention in STEMI were combined. Multiple ST measures (STR at last contrast injection (LC) measured from peak value; 30, 60, 90, 120, and 240 min, residual deviation; time to steady ST recovery; and the 3-h area under the time trend curve [ST-AUC] from LC were univariably correlated with IS and predictive of mortality. After multivariable adjustment for ST-parameters and GRACE risk factors, STR at 240 min remained an additive predictor of mortality. Early STR, residual deviation, and ST-AUC remained associated with IS. Conclusions Multiple parameters that quantify the speed, amplitude, and completeness of STR predict mortality and correlate with IS.