Prediction of early death after myocardial infarction in patients with reduced left ventricular ejection fraction. The search for new indications for cardioverter-defibrillator implantation (ICD)

Abstract

The highest rate of death is in the first few weeks after myocardial infarction (MI). However, the assessment of indications for primary prevention implantable cardioverter-defibrillator (ICD) implantation should be postponed until at least 40 days after MI. Our aim was to identify the subgroup of high-risk patients with reduced left ventricular ejection fraction (LVEF) who would benefit from primary prevention ICD implantation within 40 days of MI. Out of 205 606 patients with MI, in this study, we included 18 736 patients treated invasively, with LVEF <40%, who survived until hospital discharge. Patients were divided into two groups according to the survival status at 40 days - patients who died within this period (n = 1331) and patients who survived (n = 17405). Among all patients who died within 12-months after MI, 37.7% did die during the first 40 days. Patients with cardiac arrest before hospital admission or within the first 48 hours of hospitalization (hazard ratio [HR], 3.35; 95% confidence interval [CI], 2.82-3.98; P <0.0001], cardiogenic shock before admission or during hospitalization (HR, 3.06; 95% CI, 2.62-3.59; P <0.0001), unsuccessful percutaneous coronary interventions (PCI; HR, 2.42; 95% CI, 2.11-2.84; P <0.0001), LVEF <20% (ref. LVEF ≥30%; HR, 2.75; 95% CI, 2.25-3.36; P <0.0001) had approximately threefold and patients with chronic kidney disease almost 1.5-times (HR, 1.25; 95% CI, 1.47-3.59; P = 0.0053) higher 40-day mortality compared to patients without these risk factors. The most striking differences in mortality between these subgroups were observed shortly after discharge. The highest risk of death in patients with reduced LVEF who survived until hospital discharge occurred within the first 40 days after MI. There is a possibility to select patients with the worst prognosis and treat them more aggressively.