Association between multilayer left ventricular rotational mechanics and the development of left ventricular remodeling after acute myocardial infarction.
BACKGROUND
The identification of patients at risk for developing left ventricular (LV) remodeling after acute myocardial infarction (AMI) has crucial prognostic implications. The aims of this study were (1) to investigate the relationship between peak subepicardial and subendocardial twist and infarct transmurality, as assessed using contrast-enhanced magnetic resonance imaging, and (2) to evaluate the association between peak subepicardial and subendocardial twist and LV remodeling 6 months after AMI.


METHODS
A total of 213 patients with ST-segment elevation AMIs who underwent three-dimensional echocardiography for LV volumes and functional assessment and two-dimensional speckle-tracking analysis for the evaluation of LV twist (subendocardial vs subepicardial) were retrospectively included. A subgroup of 40 patients underwent magnetic resonance imaging within 2 months for infarct size quantification.


RESULTS
Peak subepicardial twist was strongly related to infarct size (number of segments with transmural scar: r(2) = 0.526, P < .001; total scar score: r(2) = 0.515, P < .001) compared with peak subendocardial twist (number of segments with transmural scar: r(2) = 0.379, P < .001; total scar score: r(2) = 0.331, P < .001). In the overall population, 44 patients (21%) developed significant LV remodeling at 6-month follow-up (LV end-systolic volume increase ≥ 15%). These patients showed significantly more impaired peak subepicardial and subendocardial twist at baseline compared with patients without LV remodeling (4.5 ± 1.3° vs 9.4 ± 3.5°, P < .001; 7.0 ± 3.2° vs 12.9 ± 5.8°, P < .001, respectively). Importantly, peak subepicardial twist (odds ratio, 0.241; 95% confidence interval, 0.134-0.431; P < .001) and peak troponin T (odds ratio, 1.152; 95% confidence interval, 1.006-1.320; P = .041) were independently associated with the development of LV remodeling.


CONCLUSIONS
Peak subepicardial twist strongly reflects infarct transmurality as assessed with magnetic resonance imaging and is independently associated with LV remodeling after AMI.