Influence of prior myocardial infarction on outcome in patients with ischaemic HFrEF: insights from the EVIdence based TreAtment in Heart Failure (EVITA-HF) registry

The incidence and prevalence of heart failure (HF) have been growing over the last several decades [1‐6]. HF of origin has become increasingly common because of the improved survival of patients with acute myocardial infarction (AMI) [1, 7, 8]. However, knowledge about the clinical differences and their impact on the prognosis of patients with ischaemic HFrEF is limited [1, 9]. Treatment of AMI and HF has improved substantially. Thus, the population at risk for sudden cardiac death (SCD) may also have been altered. However, data from previous trials may no longer be applicable [1, 10]. The pathophysiological substrate of ischaemic HFrEF is heterogeneous, varying from predominantly hibernating myocardium to irreversible scarring [7]. Registries have been developed to improve the quality of care and outcomes for patients with HF [11]. The aim of the present subanalysis of the EVIdence based TreAtment in Heart Failure (EVITA-HF) registry [12] was to analyse the effect of prior MI on the prognosis of patients with ischaemic HFrEF.

EVITA-HF is a registry of HF patients from 16 German tertiary care centres which includes the whole spectrum of diagnostic and treatment modalities for HF (Fig. 1). Patients were hospitalized in one of the 16 participating hospitals and had to be included consecutively [12]. As described by von Scheidt et al. [13], the inclusion criteria were chronic HF ≥ 3 months and a documented ejection fraction ≤ 40%. The diagnosis of ischaemic HFrEF was made by experienced cardiologists considering a history of myocardial infarction, and/or the electrocardiogram (any pathologic Q waves in relevant anterior or inferior leads), and/or the echocardiogram (any relevant akinesia consistent with a former myocardial infarction with explains the reduced LV function), or the coronary angiography (occlusion of any large coronary artery without relevant collaterals; only if available, was not demanded), or the cardiac magnetic resonance tomography (any relevant ischaemic scar consistent with former myocardial infarction; only if available, was not demanded). The exclusion criterion consisted of patients aged younger than 18 years or who provided no consent. Patient data were collected using a web-based electronic case report form (eCRF). Data management was performed at the Institut für Herzinfarktforschung Ludwigshafen, Germany. The registry was approved by the ethics committees of the participating centres [12]. Details of the methods used in the EVITA-HF trial were published previously [12, 13]. The EVITA-HF trial started in January 2009 and included 4101 patients as of November 2015. Baseline information concerning demographics, medical history, clinical evaluation, and diagnostics as well as pharmacological and non-pharmacological treatment, quality of life and adverse events during index hospitalization were gathered by eCRF. One-year follow-up was performed by phone calls and/or contact by the centre or general practitioner. Follow-up data consisted of vital status, adverse events and interventions since index discharge and current health status, pharmacological treatment and quality of life. One-year follow-up was defined as status obtained between 300 and 450 days after index discharge.

Here we present the data of all patients with ischaemic HFrEF. The Minnesota Living With Heart Failure Questionnaire (MLWHFQ) was used to evaluate the quality of life of patients with HF. The questionnaire comprises 21 questions about several physical, emotional and socioeconomic aspects that can adversely affect a patient’s life.

The main finding of the present subanalysis of the EVITA-HF registry was that patients with ischaemic HFrEF and a history of prior MI represented a high-risk subgroup within patients with ischaemic HFrEF. We found that more than one-third of patients with ischaemic HFrEF had no history of prior MI. To the best of our knowledge, this is the first comparison of ischaemic HFrEF patients with and without prior MI [1]. A history of prior MI in patients with HF and ischaemic HFrEF in our population was associated with higher all-cause mortality after 1 year, higher event rates and worse health status.

The diagnosis of ischaemic HFrEF was based on clinical judgment and investigator-reported aetiology, so misclassifications cannot be fully excluded. In patients with left ventricular dysfunction “out of proportion” to the extent of CAD, the clinical diagnosis of ischaemic HFrEF provides misleading information about expected outcomes. More than 81% of our population were men, so the findings may be not representative for all genders. CMR was not routinely performed in our patients to overcome this limitation. Patients who met the inclusion criteria for patients with chronic systolic HF and an ejection fraction ≤ 40% were considered to have newly diagnosed HF, and patients with HF and a preserved ejection fraction were excluded. All the participating study centres were German tertiary care centres providing the full spectrum of diagnostic and treatment modalities; patients treated in other care settings were not included. Given that EVITA-HF comprises a nonrandomized registry, the contributions of other covariables in addition to the presence of prior MI to reported outcomes cannot be fully excluded. In addition, further information concerning the dosage of medication and the reasons for limited ICD and CRT use should be analysed. Newer heart failure medications such as sacubitril/valsartan or SGLT2 inhibitors were not available at the time of data collection.

The present subanalysis of the EVITA-HF-registry focused on the influence of prior MI on prognosis in patients with ischaemic HFrEF compared to patients with no prior MI. Approximately two-thirds of patients with ischaemic HFrEF had a history of prior MI, which was associated with increased mortality, increased event rate, and worse health status. Hence, the subgroup of patients with ischaemic HFrEF and prior MI is at an increased risk and deserves special attention.