Author + information
- Derek Chewa,b,
- Rozsa Sasa,b,
- Haris Vaida,b,
- Katherine Kavanagha,b,
- Caroline Liong Eng Tan-Mesiatowskya,b,
- Danielle Southerna,b,
- Andrew Howartha,b,
- James Whitea,b,
- Stephen Wiltona,b and
- Derek Exnera,b
Background: Recovery of left ventricular ejection fraction (LVEF) after myocardial infarction (MI) is not universal and is difficult to predict. Fragmented QRS (fQRS) complexes are thought to be a marker of myocardial scar, and are defined as various RSR’ patterns on a 12-lead surface electrocardiogram (ECG), including the presence of an additional R wave (R’), notching in the nadir of the S wave, or the presence of one or more R’ in contiguous leads corresponding to a major coronary artery territory. We hypothesized that fQRS complexes on surface ECG in the initial post-MI period would be associated with changes in LVEF over the 12 months after an MI.
Methods: Change in LVEF in the early (0-2 month) versus later (2-12 month) post-MI periods was assessed in two independent cohorts, the Risk Estimation Following Infarction Noninvasive Evaluation (REFINE) and the Acute Myocardial Infarction Quality Assurance (AMIQA), by echocardiography or radionuclide ventriculography. Patients were categorized as having no recovery [Δ ≤ 0%], a modest increase [Δ 1 – 9%] or a large increase [Δ ≥ 10%] in LVEF over 12 months as compared to early after MI. fQRS complexes were measured within a median of 3 days post-MI. The relationship between LVEF change and fQRS was assessed in Cox multivariable models. A subset of 113 patients underwent magnetic resonance imaging (MRI) for quantification of myocardial scar.
Results: Of 693 MI patients, a sizable proportion (27%) had a clinically relevant decline in LVEF (mean absolute decline 4%). The presence of fQRS complexes was associated with a higher risk of no favorable remodeling (Hazard Ratio 2.0, 95% Conf. Int. 1.4 to 2.9, p<0.001), independent of prior MI or CABG, baseline LVEF, MI location and QRS duration. In the subgroup undergoing cardiac MRI, fQRS was associated with increased peri-infarct zone (11 ± 4% vs. 13 ± 5%, p=0.02), but not core infarct by the full-width-at-half-maximal method (i.e., grey zone defined as 35% ≤ SI ≤50%).
Conclusions: Despite contemporary post-MI therapy, over 1 in 4 patients have a decline in LVEF. Fragmented QRS complexes on 12-lead surface ECG early post-MI may be a useful surrogate for myocardial scar, and is associated with a lack of favorable LV remodeling.
Poster Hall, Hall C
Saturday, March 18, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Acute Coronary Syndromes, Diagnosis, Management and Outcomes
Abstract Category: 2. Acute and Stable Ischemic Heart Disease: Clinical
Presentation Number: 1253-326
- 2017 American College of Cardiology Foundation