Prognostic Value of Cardiac MRI-derived Left-to-Right Global Longitudinal Strain Ratio in ST-Elevation Myocardial
Yun Zhao1, Jing-Ping Wu1, Si-Ying Cao1
1Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University School of Medicine, No.160 PuJian Rd, Shanghai 200127, China.
Abstract:
Purpose To investigate the association between biventricular imbalance, as reflected by the left ventricular (LV) and right ventricular (RV) global longitudinal strain (GLS) ratio derived from cardiac MRI feature tracking, and all-cause death in isolated left ventricular myocardial infarction. Materials and Methods In this multicenter retrospective study, the primary end point was all-cause mortality. The GLS ratio was defined as the ratio of LVGLS and RVGLS. Long-axis (two, three, and four chambers) and short-axis cine sequences were used for strain analysis. Kaplan-Meier curves, Cox proportional hazards regression, and the C statistic were used for statistical analysis. Results In the internal testing set (919 patients; median age, 59 years [IQR, 51-66 years]; 769 [83.7%] male), 90 (9.8%) patients died over a median follow-up period of 60.9 months (IQR, 47.7-83.6 months). The GLS ratio was the strongest independent predictor for all-cause death (adjusted hazard ratio [HR], 1.69; 95% CI: 1.45, 1.97; P < .001). The model, along with clinical conventional imaging, RVGLS, and GLS ratio, demonstrated improved discrimination (C statistic, 0.82; 95% CI: 0.76, 0.87) and calibration (χ2, 71.88). A GLS ratio of more than 0.95 was responsible for a fourfold death risk after multivariable adjustment. In those with normal RVGLS (HR, 2.43; 95% CI: 1.15, 5.10; P = .02), reserved LVGLS (HR, 5.38; 95% CI: 2.46, 11.79; P < .001), and both (HR, 7.76; 95% CI: 2.16, 11.90; P = .002), a high GLS ratio (>0.95) still predicted all-cause death. Conclusion In isolated LV myocardial infarction, an elevated GLS ratio may provide additional prognostic information for all-cause death.
