Abstract 18015: Short and Long-Term Outcome of Impedance-Guided Preemptive Therapy Provided to Prevent Heart Failure in the Course of Acute Myocardial Infarction

Abstract

Background Patients sustaining acute myocardial infarction (AMI) frequently develop acute heart failure (AHF) during hospitalization. Currently, treatment is initiated after the appearance of signs of lung fluid overload. Ongoing monitoring of the status of lung fluid content (LFC) may enable the prediction of impending AHF. Aims We sought to find out whether non-invasive lung impedance (LI) guided preemptive treatment of AMI patients improves clinical outcomes. Methods LI was determined by new noninvasive method. We have shown that a decrease of 12-14% from normal LI value reflects the transition from interstitial to alveolar edema. In the present study we prospectively randomized 213 patients (2:1 ratio) admitted for first AMI with no history of chronic heart failure (CHF) or signs of heart failure at admission and whose LI decreased by >12% to conventional therapy or LI-guided preemptive treatment. Results 142 patients were treated conventionally (Gr1) and 71 preemptively according to LI (Gr2). Groups were well matched. All Gr1 patients developed AHF. Treatment was begun only at symptom onset. In Gr2 LI-guided preemptive treatment was initiated at the asymptomatic stage of evolving AHF and halted its progression in 89% of patients. Unadjusted analysis has shown that hospital stay, 1-year re-hospitalization rate after discharge, 6-year occurrence of new CHF and survival rate were better in Gr2 patients (p<0. 001). Adjustment for age, LVEF, maximal CK, diabetes, hypertension, hyperlipidemia, smoking, level of creatinine and hemoglobin at admission have shown that LI-guided preemptive treatment was associated with better clinical outcome. Length of hospital stay (OR=5.28, CI: 3.10-8.09, p<0.0001), 1-year re-hospitalization rate (OR=3.62, CI:2.16-6.06, p<0.001), 6-years occurrence of new CHF (OR=3.41, CI:1.26-7.47, p=0.002) and 6-years mortality (OR=3.19, CI:1.13-9.01, p=0.028) were lower in Gr2 than in Gr1. The major factors influencing clinical outcome were age, diabetes mellitus, LVEF <30% and maximal CK (>2216 mg/dl) (p<0.001). Conclusion s LI-guided preemptive therapy prevents the occurrence of AHF in 89% of patients, and decreases hospital stay, recurrent admissions, evolution to CHF and mortality during follow-up.