Long-term predictive value of MPI with PET and ¹³N-ammonia

Objectives We assessed the long-term predictive value of MPI with ¹³N-ammonia PET in a large number of patients with suspected myocardial perfusion abnormality.

Methods Cardiac perfusion was visually assessed in 943 consecutive patients after undergoing ¹³N-ammonia PET, and follow-up was obtained in 698 (74%). 77 patients who underwent early revascularization (<60 days) were excluded and 621 patients were assigned to normal versus abnormal perfusion for outcome analysis. Hard events (cardiac death and non-fatal myocardial infarction) and major adverse cardiac events (MACE; hard events, hospitalization for cardiac reasons and late revascularization) were analyzed using the Kaplan-Meier method. Independent predictors for various cardiac events were identified using Cox proportional hazard regression analysis.

Results A MACE was observed in 275 patients over a mean follow-up of 5.7±2.5 years, including 102 cardiac deaths and 33 non-fatal myocardial infarction. Abnormal perfusion (n=469) was associated with a higher incidence of MACE (P<0.001) and hard events (P<0.001) throughout the 10-year follow-up period.

Conclusions Cardiac perfusion findings in ¹³N-ammonia PET are strong predictors of long-term outcome.

Research Support The study was supported by grants from the Swiss National Science Foundation (SNSF) to PAK and to MF