Author + information
- Received February 26, 2013
- Revision received May 24, 2013
- Accepted May 30, 2013
- Published online August 1, 2013.
- Mads Ersbøll, MD, PhD∗,†∗ (, )
- Nana Valeur, MD, PhD‡,
- Mads Jønsson Andersen, MD∗,
- Ulrik M. Mogensen, MD∗,
- Michael Vinther, MD, PhD§,
- Jesper Hastrup Svendsen, MD, DSci∗,
- Jacob Eifer Møller, MD, PhD, DSci∗,
- Joseph Kisslo, MD†,
- Eric J. Velazquez, MD†,
- Christian Hassager, MD, DSci∗,
- Peter Søgaard, MD, DSci⋮ and
- Lars Køber, MD, DSci∗
- ∗The Heart Centre, Department of Cardiology, Rigshospitalet, Copenhagen University, Copenhagen, Denmark
- †Cardiac Diagnostic Unit, Duke University Health System, Durham, North Carolina
- ‡Department of Cardiology, Herlev Hospital, Herlev, Denmark
- §Department of Cardiology, Gentofte Hospital, Gentofte, Denmark
- ⋮Faculty of Health Science, Aalborg University Hospital, Aalborg, Denmark
- ↵∗Reprint requests and correspondence:
Dr. Mads Ersbøll, Cardiac Diagnostic Unit, Duke University Medical Center, 40 Duke Medicine Circle, Durham, North Carolina 27710.
Objectives This study sought to hypothesize that global longitudinal strain (GLS) as a measure of infarct size, and mechanical dispersion (MD) as a measure of myocardial deformation heterogeneity, would be of incremental importance for the prediction of sudden cardiac death (SCD) or malignant ventricular arrhythmias (VA) after acute myocardial infarction (MI).
Background SCD after acute MI is a rare but potentially preventable late complication predominantly caused by malignant VA. Novel echocardiographic parameters such as GLS and MD have previously been shown to identify patients with chronic ischemic heart failure at increased risk for arrhythmic events. Risk prediction during admission for acute MI is important because a majority of SCD events occur in the early period after hospital discharge.
Methods We prospectively included patients with acute MI and performed echocardiography, with measurements of GLS and MD defined as the standard deviation of time to peak negative strain in all myocardial segments. The primary composite endpoint (SCD, admission with VA, or appropriate therapy from a primary prophylactic implantable cardioverter-defibrillator [ICD]) was analyzed with Cox models.
Results A total of 988 patients (mean age: 62.6 ± 12.1 years; 72% male) were included, of whom 34 (3.4%) experienced the primary composite outcome (median follow-up: 29.7 months). GLS (hazard ratio [HR]: 1.38; 95% confidence interval [CI]: 1.25 to 1.53; p < 0.0001) and MD (HR/10 ms: 1.38; 95% CI: 1.24 to 1.55; p < 0.0001) were significantly related to the primary endpoint. GLS (HR: 1.24; 95% CI: 1.10 to 1.40; p = 0.0004) and MD (HR/10 ms: 1.15; 95% CI: 1.01 to 1.31; p = 0.0320) remained independently prognostic after multivariate adjustment. Integrated diagnostic improvement (IDI) and net reclassification index (NRI) were significant for the addition of GLS (IDI: 4.4% [p < 0.05]; NRI: 29.6% [p < 0.05]), whereas MD did not improve risk reclassification when GLS was known.
Conclusions Both GLS and MD were significantly and independently related to SCD/VA in these patients with acute MI and, in particular, GLS improved risk stratification above and beyond existing risk factors.
Financial assistance was provided by Fondation Juchum, Switzerland; Beckett Fonden, Denmark; Toyota Fonden, Aase og Ejnar Danielsens Fond, Knud Højgaards Fond, Bønnelykke Fonden, Direktør Ib Henriksens Fond, Etly og Jørgen Stjerngrens Fond, Christian og Otilia Brorsons Rejselegat for yngre videnskabsmænd og kvinder, Augustinus fonden and Fonden til Lægevidenskabens Fremme, Denmark. Dr. Ersbøll has been a speaker at a symposium for GE heatlhcare. Dr. Svendsen has received a research grant from, and has been a member of the Speakers' Bureau and Advisory Board for Medtronic; and has been a member of the Speakers' Bureau for Merck Sharp and Dohme. Dr. Kisslo has been a member of the Speakers' Bureau for Philips. Dr. Køber has been a speaker at symposia for Servier. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received February 26, 2013.
- Revision received May 24, 2013.
- Accepted May 30, 2013.
- American College of Cardiology Foundation