Diagnosis and Treatment of Asymptomatic Left Ventricular Systolic Dysfunction after Myocardial Infarction

The increased survival after acute myocardial infarction induced an increase in heart failure with left ventricular systolic dysfunction. Early detection and treatment of asymptomatic left ventricular systolic dysfunction give the chance to improve outcomes and to reduce costs due to the management of patients with overt heart failure. 1. Introduction Despite substantial progresses in the diagnosis and treatment of acute myocardial infarction (AMI), about 22% of men and 46% of women will be disabled with heart failure (HF) within six years [1]. About 40% of patients with an AMI develop left ventricular systolic dysfunction (LVSD) with or without signs of HF, which adversely influences quality of life, hospitalization rates, and mortality [2]. Considering the high survival rate after an AMI and the higher incidence of LVSD, early detection of people at risk of developing HF after an AMI should constitute a priority. Patients who have had an AMI, but who do not show signs of HF, could be burdened with an asymptomatic LVSD or stage B HF (Figure 1), according to ACC/AHA Guidelines of 2009 [3]. This condition is often not diagnosed and, for this reason, not treated, even if morbidity and mortality are similar to those of symptomatic HF [3]. Besides this, these patients run a higher risk because they are not aware of their pathology. Our aim is to underline the importance of an early detection of patients with asymptomatic LVSD in order to take all the measures that are necessary to reduce morbidity and mortality connected to this condition. Figure 1: Stages of heart failure (Adapted from [ 3]). 2. Epidemiology In occidental countries, coronary heart disease (CHD) is the most important cause of LVSD and HF [4]. Ischemic cardiomyopathy is the underlying cause in about 61% of patients with signs and symptoms of HF [5]. In the SAVE trial, asymptomatic LVSD was present in 58% of patients after an AMI [6]. Robust epidemiological data about the prevalence of asymptomatic LVSD after an AMI are hard to find. Surveys indicate that only about 60% of patients with an AMI have their ventricular function assessed [7]. Hellermann et al. conducted a review of the literature between 1978 and 2000, finding that the incidence of HF was reported only in few studies and in none of these studies diagnostic criteria for assessing HF were given [8]. If the Killip classification is used, patients with asymptomatic LVSD should be classified as Killip class 1 (no evidence of pulmonary congestion or shock). Possibly the most relevant data on the incidence, prevalence, and persistence