Predictive Accuracy of Magnetocardiography for Diagnosing Myocardial Ischemia in NSTE-ACS Patients With Residual Post-PCI Angina.

BACKGROUND

Post-percutaneous coronary intervention (PCI) angina affects 20% to 40% of non-ST-segment elevation acute coronary syndrome (NSTE-ACS) survivors but remains a clinical challenge due to its unpredictable course.

OBJECTIVES

This study aimed to validate a rapid 90-second optically pumped magnetometer magnetocardiography (OPM-MCG) test for diagnosing post-PCI angina and develop a predictive model using dynamic MCG parameters.

METHODS

NSTE-ACS patients who underwent pre- and post-PCI OPM-MCG scans were included. Angina symptoms were assessed using the Seattle Angina Questionnaire Short Form-7, with post-PCI angina defined as a Seattle Angina Questionnaire angina frequency score <100 at 3 months. Changes in 65 MCG-derived parameters (Δ parameters) were evaluated. Predictors of post-PCI angina were identified via stratified bootstrap least absolute shrinkage and selection operator regression (1,000 iterations; variables retained if selected >70% of iterations). A final model was optimized and validated internally. Performance was evaluated using receiver operating characteristic curves, calibration, and decision curve analysis.

RESULTS

This study included 363 NSTE-ACS patients who underwent PCI, of whom 134 (36.9%) experienced post-PCI angina. Patients with post-PCI angina had higher body mass index, more frequent history of PCI, and greater use of oral nitrates. The OPM-MCG model, incorporating five Δ parameters (ΔRoART, ΔNPAmax, ΔMAmax, ΔCPPPPmax, and ΔCAmax), demonstrated strong diagnostic performance with an average area under curve of 0.85 (95% CI: 0.78-0.93) during bootstrapping. The final model achieved an area under curve of 0.79 (95% CI: 0.78-0.80) with 10-fold cross-validation.

CONCLUSIONS

The OPM-MCG model provides a reliable, noninvasive, and quick tool for identifying post-PCI angina in NSTE-ACS patients, highlighting its clinical value for risk stratification, guiding personalized pharmacologic therapy, and follow-up strategies.