Prognostic significance of non-perfusion parameters of cadmium-zinc-telluride single-photon emission computed tomography myocardial perfusion imaging for individuals with normal myocardial perfusion: a large-scale single-center retrospective cohort study.

PURPOSE

The study aimed to assess the prognostic value of non-perfusion parameters for gated myocardial perfusion imaging (MPI) performed using Cadmium-Zinc-Telluride (CZT) single-photon emission computed tomography (SPECT) for individuals with normal myocardial perfusion.

METHODS

We analyzed data from consecutive patients who underwent thallium-201 MPI SPECT with normal perfusion. Major adverse cardiovascular events (MACEs) were recorded during a 2-year follow-up. Non-perfusion parameters were evaluated as predictors of MACEs.

RESULTS

Among 1570 patients with normal SPECT perfusion, 80 (5.1%) experienced MACEs over a mean follow-up of 22.5 ± 10.8 months: 12 (0.8%) had cardiac death, and 68 (4.3%) underwent coronary revascularization due to significant coronary artery disease. Independent predictors of MACEs included worsening post-stress ejection fraction (HR: 1.971; p = 0.008), and increased lung-to-heart ratio (HR: 2.207; p = 0.001). Kaplan-Meier analysis showed the highest MACEs' incidence in patients with two of these factors (p < 0.001). Among patients with normal resting ejection fraction, EF worsening (OR: 2.16; p = 0.004) and increased lung-to-heart ratio (OR: 1.91; p = 0.0013) both remained strong predictors.

CONCLUSIONS

Although normal myocardial perfusion typically indicates low risk for obstructive coronary artery disease, worsening post-stress ejection fraction and increased lung-to-heart ratio are crucial prognostic indicators. Importantly, these non-perfusion parameters retain their prognostic value even in patients without clinical heart failure, highlighting their relevance in comprehensive risk stratification beyond perfusion assessment alone.