Comparative Effectiveness of PET and SPECT MPI for Predicting Cardiovascular Events After Kidney Transplant

Area of Science:

• Cardiology
• Nephrology
• Nuclear Medicine

Background:

• Advanced chronic kidney disease (CKD) patients face high cardiovascular risk, persisting even after kidney transplantation.
• Pretransplant cardiac evaluation is crucial for identifying high-risk individuals needing further assessment or risk optimization before transplantation.

Purpose of the Study:

• To compare the prognostic value of pretransplant positron emission tomography (PET) myocardial perfusion imaging (MPI) versus single-photon emission computed tomography (SPECT) MPI in predicting posttransplant major adverse cardiovascular events (MACE).

Main Methods:

• A retrospective study followed 393 kidney transplant recipients who underwent pretransplant MPI (208 PET, 185 SPECT).
• Major adverse cardiovascular events (MACE) post-transplant were recorded, including myocardial infarction, stroke, heart failure, and cardiac death.
• Cox hazard regression with propensity weighting analyzed the association between abnormal MPI results (total perfusion deficit >5%) and MACE, comparing PET and SPECT.

Main Results:

• Abnormal PET MPI was significantly associated with posttransplant MACE (HR 3.02, P<0.001), while abnormal SPECT MPI showed no significant association (HR 1.39, P=0.33).
• PET MPI explained a higher relative risk of MACE (R² 0.086) compared to SPECT MPI (R² 0.007).
• Normal PET MPI identified patients with a lower annual MACE rate (2.2%) compared to normal SPECT MPI (3.6%, P<0.001).

Conclusions:

• Pretransplant PET MPI findings are more predictive of posttransplant MACE in kidney transplant recipients than SPECT MPI.
• Despite a low prevalence of obstructive coronary artery disease on MPI, PET findings offer significant prognostic information.
• Normal PET MPI may be superior to normal SPECT MPI in identifying lower-risk patients, warranting further prospective validation.