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

Purpose: 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.

Methods: 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 3 months for functional recovery by 2D echocardiography.

Results: On 3 month 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.

Conclusion: 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.