Left ventricular systolic dysfunction after acute myocardial infarction is associated with a high symptom burden and worse secondary prevention

Background LV dysfunction and symptomatic heart failure are common complications after myocardial infarction and the mortality and morbidity burden remain high in this population. Published data are becoming dated, and mainly focus on mortality and hospitalization burden. There is a lack of contemporary data describing patients with post-MI LV dysfunction in terms of symptom burden and secondary prevention measures. Purpose The purpose of this study was to describe patients with different degree of LV dysfunction after MI, their symptom burden, quality of life and adherence to recommended secondary prevention measures in a nationwide patient material. Methods We included 49,564 adults ≥18 years, registered in the SWEDEHEART registry between 2011 and 2018, diagnosed with acute MI, discharged alive and with no previous heart failure. The population was stratified by degree of LV systolic function; EF >50%, EF 40-49%, EF 30-39% and <30%, assessed by echocardiography. Patients were assessed at 6-10 weeks and 10-14 months after MI. Descriptive analyses were used for demographics and characteristics at baseline, first and second follow up. Uni- and multivariable regression analyses was used to examine the associations between LV impairment and symptoms, occupation/working status, readmissions, quality of life (Eq5D), attending cardiac rehabilitation and physical training, smoking status and snuffing. Results Patients with impaired LVEF would more often experience shortness of breath (5.6% vs 32.3% for EF < 30 vs EF >50 at second follow up) (figure). Patients with EF <30% had a lower Eq5D mean at first follow up than patients with normal LVEF (0.77 vs 0.82), but that difference was smaller at second follow-up (0.80 vs 0.83). Subjects with EF <30% did participate in heart rehabilitation to a lesser extent than those with normal EF, both at the first (28.7% vs 37.4%) as well as the second follow up (44.9% vs 55.5%). In multivariate regression analyses (table), a lower EF was associated with shortness of breath (OR = 7.47, 95% CI = 6.24-8.94) and a lower probability of working or studying (OR = 0.25, 95% CI = 0.20 – 0.31) but not with chest pain. A lower EF was also associated with a lower probability of participating in heart school (OR = 0,67, 95% CI = 0.58-0.68) and physical training (OR = 0.54, 95% CI = 0.46-0.63). Conclusion Left ventricular systolic dysfunction after acute myocardial infarction is associated with a high symptom burden and worse secondary prevention. This may indicate heart rehabilitation programs should be better adapted to this large population with great needs.