Abstract 2298: Are Non-Invasive Tests Useful in the Identification of Low Risk Post-Infarction Patients with Left Ventricular Dysfunction? A 11 Years Follow-Up
The potential role of non invasive testing, combined with left ventricular ejection fraction, in the optimization of the selection criteria for ICD therapy in patients with left ventricular dysfunction after myocardial infarction has not been yet evaluated and in this setting no data are available on long term prognosis. The present study is aimed to evaluate the ability of non-invasive markers in the identification of patients with left ventricular dysfunction after myocardial infarction at low risk of death from any cause. Of 278 patients with recent (≤ 30 days) myocardial infarction, 65 (23%) with left ventricular ejection fraction ≤ 40% represent the study group: mean age 56±9 years, thrombolysis 57%, left ventricular ejection fraction 36±4%, anterior myocardial infarction 83%, previous myocardial infarction 17%, left ventricular dyskinesia 51%, QRS duration at signal averaging ecg 105±13 msec, SDNN 106 ±38 msec, unsustained ventricular tachycardia at Holter monitoring 32%. At follow-up (11±3 years) 28 deaths (43%) were recorded. Among the above-mentioned variables, the survival Cox analysis identified as independent predictors of death from any cause, besides left ventricular ejection fraction (p=0.05), QRS duration at signal averaging (p=0.007) and the presence of unsustained ventricular tachycardia at Holter monitoring (p=0.008). In the study group 9 patients (14%) had both variables (QRS duration and unsustained ventricular tachycardia) altered (group ‘2’), 33 (51%) presented only one variable altered (group ‘1’), and 23 (35%) had no altered variables (group ‘0’). Mortality rate from any cause was 67% in group ‘2’, 54% in group ‘1’ and 17% in group ‘0’. Patients in group ‘0’ showed an average annual mortality of 1.5% during follow-up.The present analysis suggests that the normality of 2 non-invasive variables identify a subgroup of post-infarction patients with good long term prognosis, despite moderate to severe left ventricular dysfunction. Therefore non invasive tests, together with left ventricular ejection fraction, may result of help in the optimization of selection criteria of patients candidate for ICD therapy after myocardial infarction.