At present, primary angioplasty (PTCA) is preferred reperfusion treatment for acute ST elevation myocardial infarction (STEMI). Risk stratification after STEMI includes the evaluation of left ventricular (LV) function. B-type natriuretic peptide testing emerged as a potential marker of LV function and prognosis after STEMI.
Aim: The objective was long-term echocardiographic assessment of LV systolic and diastolic function in patients with STEMI who underwent PTCA and to evaluation of the relationship between NT-proBNP plasma levels and LV function. We assessed the value of NT-proBNP in prediction of LV dysfunction after STEMI treated with PTCA.
Material and methods: A series of 98 patients (pts) (75 males, 23 females age from 50.0 to 63.0, mean age 55.0), treated successfully with PTCA in acute phase of STEMI were included in this study. NT-proBNP plasma levels were assessed just before PTCA (BNP-bsl) and at 6 month follow-up (BNP-6m). Transthoracic echocardiography (TTE) was performed at discharge(dc) and at 6 months follow-up (6m). The indices of LV systolic function (LVSF) (LV ejection fraction-EF, wall motion score index-WMSI), LV diastolic function (LVDF) (peak velocity of early (E) and late (A) transmitral flow, E-wave deceleration time (DT), isovolumic relaxation time (IVRT)) and global LV function (Tei index- calculated as a sum of isovolumetric contraction time and IVRT divided by the ejection time) were estimated.
Results: At 6 month echocardiographic follow-up we observed the significant improvement of LVSF (the increase of EF (p < 0.0027), the decrease of WMSI (p < 0.0005)) and the deterioration of LVDF (the decrease of E/A (p < 0015), the increase of IVRT (p < 0085)). A negative correlation between BNP-bsl and EF-6m (Rs = -0.2877, p < 0.0072) and BNP-6m and EF-6m (Rs = 0.4125, p < 0.0001) were observed. Multivariate analysis identified BNP-bsl and CPK max during acute phase of STEMI as negative and EF-dc as positive significant, independent predictors of EF-6m.
Conclusions: The significant improvement of LV systolic function and LV abnormal relaxation were observed at 6 month follow-up in patients with acute STEMI treated with primary angioplasty. Baseline NT-proBNP plasma level, CPK max plasma level during acute phase of STEMI and echocardiographic LV systolic function indices at discharge are significant and independent predictors of LV systolic function in long-term follow up. Increasing NT-proBNP plasma level at 6 month after STEMI treated with PTCA has a good performance in detecting of LV systolic function deterioration in long-term follow-up.