Decreased myocardial uptake on technetium-99 m sestamibi (99mTc-MIBI) imaging was associated with reduced exercise capacity and adverse outcomes in adults with non-ischaemic cardiomyopathy (NICM). Findings presented at the European Society of Cardiology (ESC) 2025 highlight the value of combining myocardial imaging with exercise testing for risk assessment.

The study retrospectively analyzed 182 inpatients with non-ischaemic cardiomyopathy (mean age 51.4 years; 27% female; left ventricular ejection fraction <50%) who underwent technetium-99 m sestamibi scintigraphy and cardiopulmonary exercise testing. Patients with a percentage of predicted peak oxygen consumption ≤60% had higher summed rest scores, indicating greater myocardial damage (median 12 [IQR 7–18] vs 8 [IQR 5–12]; P<0.001). During a median follow-up of 807 days, 13% experienced adverse events including death, ventricular assist device implantation, or heart transplantation.

Higher summed rest scores independently predicted poorer outcomes (hazard ratio 1.085, 95% confidence interval 1.048–1.123; P<0.001), along with low exercise capacity (hazard ratio 3.197, 95% CI 1.124–9.094; P=0.020). Patients with both low exercise capacity and high myocardial damage faced the greatest risk.
These findings suggest that technetium-99 m sestamibi imaging, combined with exercise testing, can enhance risk stratification in non-ischaemic cardiomyopathy.