Role of strain imaging for assessment of myocardial viability in symptomatic myocardial infarction with single vessel disease: An observational study.

Abstract

To study and evaluate the predictive value of strain imaging parameters in patients undergoing viability assessment postmyocardial infarction (MI) in comparison with Dobutamine stress echocardiography (DSE) alone. This was a prospective observational study (October, 2016-March, 2018), which recruited 100 symptomatic patients with MI, and angiographically proven single vessel disease, LV dysfunction with severe hypokinesia/akinesia on 2D echocardiography and viability proven by baseline DSE. Patients undergoing primary PCI were excluded. Patients were recruited in two groups: DSE alone (first group) and strain imaging with DSE (second group). Revascularization was done in all patients. Patients were assessed at 3months for functional recovery by 2D echocardiography. On 3month follow-up after revascularization, 37 patients (74%) in first group and 33 patients (66.67%) in second group had functional recovery. Dobutamine-stimulated strain parameters such as circumferential strain (CS; P=.005), radial velocity (RV; P<.001), longitudinal strain (LS; P<.001), and longitudinal strain rate (LSR; P<.001) were found to be a significant predictor of viability. The greatest area under the curve (AUC) for the ROC curves was obtained for low dose dobutamine RV (AUC=0.92), low dose dobutamine LS (AUC=0.94), and low dose dobutamine LSR (AUC=0.88). Positive predictive value of the combination of low dose DSE with strain parameters (RV-97.2%, LS-97.4%, and LSR-87.5%) for myocardial viability was significantly higher than low dose DSE positive/low dose strain parameters negative patients as well as low dose DSE group alone. Evaluation of strain parameters with low dose DSE is clinically feasible for the detection of myocardial viability and adds incremental value to the subjective and semiquantitative wall-motion scoring. LS at low dose DSE with WMSI was found to have the highest positive predictive value.