Abstract 326: Patterns of PET and SPECT Utilization in an Integrated Healthcare System With Both Modalities: Comparison of Referred Patients, Referral Sources, and Appropriateness in Relation to Published Criteria
Background: Appropriate Use Criteria for cardiac procedures and treatments have focused interest on utilization patterns, drivers, and appropriateness. Rest/stress radionuclide myocardial perfusion imaging (MPI) is frequently performed using SPECT, while PET is becoming more widely available with increasing data demonstrating value for selected patients. Currently there is no data examining how SPECT and PET are being utilized when both are available.
Methods: Our institution has 4 sites with cardiac-dedicated SPECT and PET. We prospectively enrolled all patients (pts) who underwent a SPECT or PET from 9/15/2008 to 9/26/2008. Charts were intensively audited with respect to pts descriptors, referral sources, and test indications according to the 52 categories in the 2005 Appropriateness Criteria. Indications were classified according to those criteria as appropriate, inappropriate or uncertain. SPECT and PET pts, referral sources, and referral indications/classifications were compared. Categorical variables were analyzed with χ2 and continuous variables with the Student’s t-test.
Results: A total of 537 pts were enrolled and evaluated: PET = 173 pts (32%), SPECT = 364 (68%). PET pts were significantly older (70 v 61 yrs), and were more likely to be hospitalized (26.2% v 14.6%), have a prior history of CAD (65% v 34%), to have dyspnea as a presenting symptom (55% v 40%), and to have hypertension or dyslipidemia (all p <0.05). PET referrals were more likely to be from a cardiologist (92%), while 43% of SPECT referrals were from non-cardiologists (p<0.001). 499 pts had adequate data to classify appropriateness: in these patients there were no significant overall differences between PET and SPECT: 79% v 73% were appropriate, 10% v 16% were inappropriate, and 10.8% v 11.4% were in the uncertain category (p=0.19). However, all but 6 of the 38 pts who could not be classified were asymptomatic SPECT pts.
Conclusions: Our study shows significant differences in utilization pattern between PET and SPECT, with PET being used more frequently in older patients with more acute illness and already known CAD. Although PET and SPECT referral sources differ, a similar small percent are inappropriate referrals according to published Criteria.