Predicting mortality using relative apical strain in patient after anterior ST-elevation myocardial infarction
J Gouveia Fiuza, M Duarte Almeida, F Rodrigues Dos Santos, O Kungel, L Afonso Santos, G R M Ferreira, J Gil, N Craveiro, A CostaAbstract
Introduction
In anterior ST-elevation myocardial infarction (AMI), myocardial injury frequently involves the apex. Global longitudinal strain (GLS) predicts adverse outcomes but averages segment deformation, potentially masking critical regional disparities. We hypothesized that a relative apical strain index (RASi), reflecting the apical to non-apical gradient, combined with clinical variables, would improve prediction of all-cause mortality (ACM) compared with conventional parameters.
Methods
Retrospective single-centre cohort study of 45 patients admitted with anterior AMI who underwent transthoracic echocardiography (median 3 days post-admission). Left ventricular longitudinal strain (LS) was measured in apical, mid and basal segments to derive RASi (average apical LS/(average basal LS + mid-LS)). We then developed the RASK score (Risk Assessment using Age, relative Strain and Killip class), a 0-3 point tool. We assigned 1 point for each of the following variables: abnormal apical strain pattern (RASi≤0), age>70 years, and Killip class ≥II at admission. The primary endpoint was 12-month ACM. Discriminative performance was assessed using receiver operating characteristic (ROC) analysis and compared with left ventricular ejection fraction (LVEF) and GLS.
Results
The study population had a mean age of 66±14 years, 77.8% were male, and a mean LVEF of 42±9%. All-cause mortality was 13.3% (n=6). LVEF (42±9% vs 40±9%, p=0.53) and GLS (−8.9±3.1% vs −7.3±2.9%, p=0.27) did not differ significantly between survivors and non-survivors. In contrast, non-survivors were older (80±7 vs 65±14 years, p=0.012) and presented more negative RASi values (−0.23±0.34 vs 0.10±0.32, p=0.028), indicating inversion of the usual base-to-apex gradient. Higher Killip class showed a trend towards increased mortality (2.2±0.9 vs 1.5±0.7, p=0.087). The RASK Score showed excellent discrimination for mortality (AUC 0.86; 95% CI 0.75-0.97, p<0.01), outperforming LVEF (AUC 0.42) and GLS (AUC 0.69). A score ≥2 identified all non-survivors (100% sensitivity). Mortality was 0% for low scores (0-1) versus 33.3% for high scores (≥2; p=0.014), indicating effective risk stratification.
Conclusion
In patients with AMI, this simple three-item score showed superior discrimination for ACM compared with LVEF and GLS in this cohort. Low scores (0-1) identified patients with excellent short-term prognosis. Given the small sample size, external validation in larger cohorts is required before clinical use.AUC Rask ScoreFor image description, please refer to the figure legend and surrounding text.