Object There are scant comparative studies on the most reliable invasive measurement for assessing the myocardial functional recovery in ST elevation myocardial infarction patients (STEMI). The aim of this study was to evaluate usefulness of coronary physiologic parameters for the predicting the functional recovery in patient with STEMI undergoing primary percutaneous coronary intervention (PCI).
Methods 49 patients who underwent primary PCI for STEMI were enrolled. The CFR and IMR by using the pressure-temperature sensor-tipped wire were measured at infarct related artery after proper reperfusion treatment. Ratio of IMR at resting to IMR during hyperemia (IMR_ratio) was also calculated (Table 1). Theoretically, IMR_ratio could adjust the pressure change caused by coronary lesion during hyperemia and then less affected by of coronary lesion than CFR. Transthoracic echocardiography (TTE) was performed at before discharge and 6mo later. Left ventricular (LV) end diastolic volume (LVEDV), end systolic volume (LVESV) and LV ejection fraction (LVEF) were calculated with the modified Simpson���s method. Cardiac enzyme was serially checked during admission.
Results Patients were classified to recovered group (n=29, age=52짹10) and non-recovered group (n=20, age= 54짹9) according to the improvement of LVEF on the follow-up TTE. In baseline, there were no differences of LVEDV (83짹15 vs. 80짹23ml, p=0.6), LVESV (42짹10 vs. 41짹14ml, p=0.7), EF (49짹7 vs. 49짹6%, p=0.9) between recovery and non-recovery. Recovered group showed the significantly higher CFR (2.3짹1.1 vs. 1.7짹0.5, p=0.003) and IMR_ratio (2.6짹1.2 vs. 1.4짹0.4, p<0.001) than non-recovered group, but IMR (28짹27 vs. 52짹55, p=0.06) didn���t show the significant difference between two groups. IMR presented the relatively strong correlation with peak CK (r=0.48, p=0.02), whereas CFR and IMR_ratio was not correlated with peak CK. By logistic analysis, only CFR (odds ratio 6.2, 95% CI=1.529~25.52, p=0.01) and IMR_ratio (odds ratio 14.4, 95% CI=2.17~95.96, p=0.006) were strong predictors of functional recovery.
Conclusions The result of this study suggests that IMR_ratio might be stronger predictor for the functional recovery in patient with STEMI undergoing primary PCI than CFR. IMR was not a predictor of functional recovery but strongly correlated with peak CK suggesting correlation with infarct burden.