Usefulness of postsystolic shortening and early systolic lengthening to detect reduced myocardial viability and predict future cardiovascular events in ST-segment elevation myocardial infarction

Abstract

Abstract Purpose: Postsystolic shortening (PSS) and early systolic lengthening (ESL) which represent asynchrony in ischemic myocardium can provide prognostic information in patients with ST-segment elevation myocardial infarction (STEMI). We aimed to investigate the potential of PSS and ESL to detect reduced myocardial viability and investigate the comparative prognostic value of PSS and ESL in patients with STEMI after primary PCI. Methods: We prospectively enrolled 198 patients with STEMI who underwent primary percutaneous coronary intervention. All patients took a speckle tracking echocardiographic examination and myocardial contrast echocardiography a median of 3 days after the percutaneous coronary intervention. Early systolic strain index (ESI), postsystolic strain index (PSI) and myocardial perfusion score index (MPSI) were calculated. The end point was major adverse cardiovascular events (MACE), a composite of all-cause death, unstable angina, heart failure, non-fatal recurrent myocardial infarction, stroke, and complex ventricular arrhythmia. Results: Reduced myocardial viability was defined as MPSI >1. Patients with category of MPSI >1.5 increased signifcantly with increasing tertiles of PSI (1.5% vs 7.6% vs 31.8%, p <0.001) and ESI (3.0% vs 12.1% vs 25.8%, p <0.001), and the highest tertile of PSI remained significantly associated with a higher MPSI in adjusted logistic regression model (b=1.00, 95% CI, 0.25-1.75; p=0.010). Areas under the curve for PSI and ESI to determine a MPSI >1 was 0.745 and 0.704 in ROC analysis. During a median follow-up of 9.0 months (interquartile range [IQR], 6.0-12.0 months), 39 (19.7%) patients suffered MACE. PSI and ESI remained predictors of MACE in adjusted cox regression models. In ROC analysis, IDI and NRI of PSI were significantly higher compared to GLS while ESL didn’t. Conclusion: In patients with STEMI after primary PCI, PSS and ESL provides diagnostic information on reduced myocardial viability and offers prognostic information oncardiovascular events. Additionally, PSS emerged as independent predictor of mid- and long-term MACE with superior prognostic validity compared to GLS and ESL.