{
  "abstract": "Introduction Rb-82 PET myocardial perfusion imaging (MPI) is widely used to investigate angina and coronary artery disease. However, gastric tracer uptake is the most frequent image artefact and can hinder accurate contouring of inferior myocardial segments and therefore left ventricular ejection fraction quantification. Also, unlike during SPECT MPI, the short half-life of Rb-82 precludes image reacquisition after interventions to reduce gastric uptake such as eating, drinking and delayed imaging. Proton pump inhibitors (PPIs) such as omeprazole are associated with high gastric uptake. This study aimed to assess the relationship between PPI use and gastric uptake and determine whether temporary pre-scan PPI cessation reduces gastric uptake during Rb-82 PET MPI.Methods A serial cross-sectional study was conducted. The pre-intervention audit included 9,588 Rb-82 PET scans (62% male, mean age 65.1 ± 12.0y). After introducing temporary pre-scan PPI cessation, a post-intervention reaudit of 612 scans (66% male, mean age 64.8 ± 11.3y) was performed. The primary outcome, ‘high gastric uptake’, was measured with rules-based text mining of reports and validated on a 200-scan subset by comparing text-mined classifications with blinded 4-point visual intensity scoring. Statistical tests included chi-square, t-tests, and odds ratios (OR).Results Visual validation of the scan images confirmed reliability of the text-mining method in identifying gastric uptake. Specifically, scans reporting gastric uptake (n = 39) had higher mean visual scores (3.87/4) than those that did not (n = 161, 2.96/4) (p<0.0001). Visual scores were higher in PPI users (3.39/4) than non-users (2.87/4) (p = 0.001). In the pre-intervention audit, 54.9% of patients (n = 5208) were taking a PPI. Gastric uptake was significantly more common in PPI users (15.1%; 794/5,208) than non-users (7.9%; 343/4,330) (OR 2.07, 95% CI 1.81-2.36; p < 0.001). This was a class effect, with no differences between 4 different PPIs (p = 0.76). Male sex was an independent risk factor for gastric uptake both on (OR 1.61, p < 0.001) and off PPIs (OR 2.19, p < 0.001). In the post-intervention reaudit, adherence to PPI cessation was 37.8% (150/396) and associated with significantly lower rates of reported gastric uptake (24.0%) than non-adherence (33.3%) (OR 0.63; p = 0.048), yielding a NNT for pre-scan PPI cessation = 11.Conclusion PPI use and male sex are strong, independent predictors of significant gastric uptake on Rb-82 PET scans. Temporary PPI cessation before Rb-82 PET MPI reduces gastric uptake. This large serial cross-sectional study is the first to demonstrate in a clinically-derived cohort of Rb-82 PET MPI scans that PPI use is strongly associated with increased gastric uptake, that temporary pre-scan PPI cessation reduces this uptake, that the effect is consistent across different PPIs, and that male sex is a novel independent risk factor.",
  "authors": [
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Sofiane Kouadria"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Rio Estoroque"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Susana Lousada"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Chris Orongan"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Nélio Fernandes"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Shane Cashin"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Idris Badreddine"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Tahir Hussain"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "Leon Menezes"
    },
    {
      "affiliations": [
        "Barts Health NHS Trust, London, United Kingdom"
      ],
      "name": "George Collins"
    }
  ],
  "title": "27 Temporary pre-scan proton pump inhibitor cessation reduces gastric tracer uptake in patients undergoing Rb-82 PET myocardial perfusion imaging",
  "uid": "50cb7656-d552-52a7-b4bd-bc4114703690"
}