Patient-level diagnostic performance of myocardial contrast echocardiography using ultrasound-enhancing agents after acute myocardial infarction: comparison with radionuclide perfusion-metabolism imaging

Objective This study evaluated the patient-level diagnostic performance and agreement of myocardial contrast echocardiography (MCE) for assessing myocardial viability after acute myocardial infarction (AMI), using combined radionuclide perfusion-metabolism imaging as the reference standard. Methods This retrospective diagnostic-comparison study included 141 patients with AMI who underwent MCE and reference radionuclide perfusion-metabolism imaging between February 2017 and February 2023. Imaging was generally performed during the subacute phase, 7–14 days after symptom onset. Reference assessment combined 99 mTc-MIBI myocardial perfusion imaging with 18 F-FDG metabolic imaging. The standardized 17-segment left ventricular model was used as an anatomical framework for image interpretation; however, because individual segment-level classifications were not systematically archived, diagnostic performance was evaluated at the patient level. MCE examinations were interpreted independently by experienced cardiologists blinded to the reference imaging results, with disagreements resolved by consensus. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and Cohen's kappa were calculated with 95% confidence intervals (CIs). Results Reference imaging classified 91 patients as having viable myocardium and 50 as having non-viable myocardium. MCE yielded 79 true-positive, 44 true-negative, 6 false-positive, and 12 false-negative classifications. Patient-level sensitivity was 86.81% (95% CI, 78.35%–92.29%), specificity was 88.00% (95% CI, 76.20%–94.38%), and overall accuracy was 87.23% (95% CI, 80.72%–91.77%). PPV was 92.94% (95% CI, 85.44%–96.72%), and NPV was 78.57% (95% CI, 66.18%–87.29%). Agreement between MCE and reference imaging was substantial (Cohen's κ = 0.728; 95% CI, 0.612–0.845; P < 0.001). Conclusion MCE demonstrated substantial patient-level agreement with radionuclide perfusion-metabolism imaging for post-AMI myocardial viability assessment. These findings support its potential role as a complementary diagnostic imaging modality under the evaluated conditions. However, the present study did not assess subsequent functional recovery, ventricular remodeling, revascularization benefit, treatment decisions, or clinical outcomes; therefore, no conclusions regarding patient-management benefit or prognostic utility can be drawn from these data.