Abstract 14586: Variability in Indicated Left Ventricular Function Reassessment After Mi: The Acute Myocardial Infarction Quality Assurance (AMIQA) Canada Multicenter Prospective Study

Abstract

Introduction: Persistently reduced LVEF after acute MI predicts adverse prognosis and directs use of evidence-based treatments to prevent sudden death (SCD) and/or progressive heart failure. We conducted a multicentre, prospective, observational study to assess adherence with guideline recommendations to repeat imaging assessment post-MI in those with initially depressed LVEF. Methods: We enrolled 501 patients with type 1 acute MI and LVEF ≤45% during the index hospitalization, from 14 Canadian sites. Outcomes were the proportion having a repeat LVEF assessment by 6 months and the proportion with an actionable reduced LVEF in follow-up: <35%, prompting referral for ICD therapy; <40%, prompting consideration of additional heart failure therapy; or 36% to 50%, prompting referral for participation in SCD risk reduction research Results: Mean age was 63.3 ± 13.0, and 113 (22.6%) were female. Overall, 370 (73.4%) presented with STEMI, and 454 (91.6%) had one or more in-hospital revascularization procedures. The mean baseline LVEF was 36.9% ± 6.7%. Over a median follow-up of 198 days, 18 (3.6%) patients died and 27 (5.3%) were lost to follow-up. Of 456 remaining patients, 303 (66.5%) had LVEF reassessment and significant variation was observed across sites (range 46.7-90.0%; p=0.035). Patients from community vs academic hospitals were more likely to undergo LVEF reassessment (73.6% vs. 63.2%, p=0.034), as were those with worse LVEF at baseline ( Figure, panel A ). In those with follow-up LVEF (n=302), 61.6% had an actionable persistent LVEF reduction: 13.9% had LVEF <35%, 28.8% had LVEF <40%, and 47.7% had LVEF between 36 and 50%, with significant variation based on initial LVEF ( Figure, Panel B ). Conclusions: One in three patients with at least mild LVEF reduction after acute MI did not undergo indicated LVEF reassessment within 6 months. In those with follow-up imaging, clinically actionable persistent LVEF reduction was identified in over one quarter of patients.