Arrhythmic risk stratification in post-myocardial infarction patients with preserved ejection fraction: the PRESERVE EF study

Abstract

Aims: Sudden cardiac death (SCD) annual incidence is 0.6-1% in post-myocardial infarction (MI) patients with left ventricular ejection fraction (LVEF)≥40%. No recommendations for implantable cardioverter-defibrillator (ICD) use exist in this population.

Methods and results: We introduced a combined non-invasive/invasive risk stratification approach in post-MI ischaemia-free patients, with LVEF ≥ 40%, in a multicentre, prospective, observational cohort study. Patients with at least one positive electrocardiographic non-invasive risk factor (NIRF): premature ventricular complexes, non-sustained ventricular tachycardia, late potentials, prolonged QTc, increased T-wave alternans, reduced heart rate variability, abnormal deceleration capacity with abnormal turbulence, were referred for programmed ventricular stimulation (PVS), with ICDs offered to those inducible. The primary endpoint was the occurrence of a major arrhythmic event (MAE), namely sustained ventricular tachycardia/fibrillation, appropriate ICD activation or SCD. We screened and included 575 consecutive patients (mean age 57 years, LVEF 50.8%). Of them, 204 (35.5%) had at least one positive NIRF. Forty-one of 152 patients undergoing PVS (27-7.1% of total sample) were inducible. Thirty-seven (90.2%) of them received an ICD. Mean follow-up was 32 months and no SCDs were observed, while 9 ICDs (1.57% of total screened population) were appropriately activated. None patient without NIRFs or with NIRFs but negative PVS met the primary endpoint. The algorithm yielded the following: sensitivity 100%, specificity 93.8%, positive predictive value 22%, and negative predictive value 100%.

Conclusion: The two-step approach of the PRESERVE EF study detects a subpopulation of post-MI patients with preserved LVEF at risk for MAEs that can be effectively addressed with an ICD.

Clinicaltrials.gov identifier: NCT02124018.

Keywords: Programmed ventricular stimulation; Arrhythmic risk stratification; Myocardial infarction; Preserved ejection fraction; Two-step approach.

Figure 1

Study flowchart and patient flow. MAE, major arrhythmic event; NIRF, non-invasive risk factors; PEP, primary endpoint (MAE occurrence); PVS, programmed ventricular stimulation—see ‘Methods’ section for more details.

Figure 2

Kaplan–Meier survival curves by risk group. No primary endpoint events occurred in Groups 1 and 2. Patients declining programmed ventricular stimulation are not depicted (unknown risk group). NIRF, non-invasive risk factor.

Take home figure

Outline of study design and findings. Starting with a cohort exhibiting a prevalence of major arrhythmic events at the 1.5% level (after a 32-month follow-up), the two-step, programmed ventricular stimulation-inclusive approach allowed for the identification of a high arrhythmic risk subgroup with a major arrhythmic event prevalence reaching 22% (almost 15-fold higher than baseline). LP, late potentials; MAE, major arrhythmic event; NIRF, non-invasive risk factors; nsVT, non-sustained ventricular tachycardia; PVC, premature ventricular complex.