Influence of proton-pump inhibitors on stomach wall uptake of 99mTc-tetrofosmin in cadmium–zinc–telluride SPECT myocardial perfusion imaging

Effect of proton pump inhibitors and H2 antagonists on gastric wall uptake in myocardial perfusion scan with 99mTc-sestamibi

BACKGROUND

Proton pump inhibitors (PPIs) have been speculated to cause gastric wall uptake (GWU) in MPI scans. However, the uptake mechanism and prevention methods are less studied. In this prospective trial we aimed to evaluate the impact of gastroprotective medications on GWU and its solutions.

METHODS

351 consecutive patients, scheduled for 2-day rest/stress 99mTc-MIBI scan, were distributed into 5 groups. 3-7 days following the baseline rest scan, the stress scan was acquired after intervention in the trial group, consisting of patients with history of PPI intake, randomly assigned to 3 subgroups: discontinuing PPIs(A), replacement with H2 blockers (B), and continuing PPIs (C). Patients receiving H2 blockers, continued it as before (D) and the remaining patients were the control group (E). GWU was graded compared to the myocardial uptake.

RESULTS

In the rest phase, all groups had significantly higher GWU compared to the control group. In the stress phase, group A had less GWU than group B (P-value < 0.05) and both of them had significantly less GWU compared to group C (P-value < 0.001). There was no significant difference between PPI discontinuation periods of 3-5 days versus 5-7 days. There was a significant association between duration of oral PPI intake, but not IV PPIs, and GWU. GWU was significantly lower with oral compared to IV PPI administration.

CONCLUSION

PPIs significantly increase GWU and discontinuing them for at least 3-5 days significantly reduces GWU. H2 antagonists are a good alternative in patients who cannot tolerate dyspepsia symptoms.

Effect of proton pump inhibitors and other commonly prescribed drugs on rescanning of patients undergoing myocardial perfusion imaging: a case-control study

OBJECTIVES

Proton pump inhibitor use is associated with increased gastric wall activity on myocardial perfusion imaging; however, the clinical impact is unknown. We sought to determine the association of the use of proton pump inhibitors and nine other commonly prescribed classes of medications on the risk of rescanning patients undergoing myocardial perfusion imaging.

METHODS

A matched case-control study was performed including 337 rescanned cases and 337 same-day controls from a total of 5432 patients undergoing myocardial perfusion imaging (MPI) over a 4-year period.

RESULTS

The odds of rescanning was higher in patients taking a proton pump inhibitor than those not [adjusted odds ratio (OR), 1.6; 95% confidence interval (CI), 1.1-2.2] and in those taking an angiotensin-converting enzyme inhibitor than those not (adjusted OR, 1.5; 95% CI, 1.0-2.2) adjusted for age, sex and BMI category. Eight other commonly prescribed medications showed no associations with rescanning. Among the cases of rescanning, the culprit organ site of extracardiac activity was the left lobe of the liver, 48%; gastric wall, 31%; gastric lumen, 12%; spleen, 7% and bowel <1%. Proton pump inhibitor use was strongly associated with rescanning due to gastric wall uptake (adjusted OR, 6.3; 95% CI, 2.8-14.1) but not the other causes of rescanning.

CONCLUSIONS

Proton pump inhibitor use and angiotensin-converting enzyme inhibitor use are associated with an increased risk of rescanning of patients undergoing MPI. Gastric wall activity is likely to account for the excess cases of rescanning in those taking a proton pump inhibitor.

Interaction between the effects of proton pump inhibitors and aspirin on gastric wall sestamibi uptake on myocardial perfusion imaging

BACKGROUND

Increased gastric wall activity on myocardial perfusion imaging (MPI) is associated with proton pump inhibitor (PPI) therapy; however, the mechanism is unknown. We proposed a role for gastric mucosal prostaglandin synthesis and asked whether concurrent use of aspirin would antagonize this effect.

METHODS

An observational study was performed of 319 patients undergoing technetium-99m sestamibi (MIBI) rest/stress MPI. We assessed the effects of taking PPIs, aspirin and their interaction on the principle outcome of clinically significant gastric wall activity.

RESULTS

The outcome was observed in 13% of patients taking neither a PPI nor aspirin, 22% of those taking aspirin only, 51% taking a PPI only and 33% of those taking both. Adjusted odd ratios (95% confidence intervals) were 6.3 (CI 2.8-14.0; p < .001) for taking a PPI only, 1.8 (CI 0.8-3.9; p = .16) for taking aspirin only, and 3.0 (CI 1.4-6.5; p = .005) for taking the combination of a PPI and aspirin. There was evidence of negative statistical interaction between the two drug effects using additive (p = .006) and multiplicative (p = .016) scales.

CONCLUSIONS

PPI use was strongly associated with enhanced gastric wall activity on MPI; however, concurrent aspirin appears to reduce the effect. Enhanced local prostaglandin synthesis may mediate the PPI effect.

Association of use of proton pump inhibitors and H2 antagonists with stomach wall uptake in 99mTc-methoxy-isobutyl-isonitrile (MIBI) myocardial perfusion imaging

BACKGROUND

Stomach wall uptake (SWU) of tracer in 99mTc-MIBI myocardial perfusion imaging (MPI) occasionally leads to imaging artifacts, thereby lowering the diagnostic accuracy. It is less-studied phenomenon for possible link with proton pump inhibitors (PPIs) intake. This prospective work looked for association of SWU with PPI intake and compared its incidence with H2 antagonists (H2A) users and patients not on either gastroprotective medication.

METHODS

One hundred fifty-six patients undergoing one day stress/rest 99mTc-MIBI SPECT-MPI were distributed into four groups: control group (n = 48, not on any gastroprotective medication), PPI group (n = 47, on PPI treatment), H2A group (n = 19, on H2A therapy), and intervention group (N = 42, PPI discontinued for 3 days before MPI). Poststress planar images were analyzed for clinically relevant SWU.

RESULTS

Clinically relevant SWU was seen in 36% of PPI group patients compared to 8% in the control group, 10.5% in the H2A group, and 9.5% in the intervention group, respectively, with statistically significant difference. Only 1/40 patients undergoing exercise stress showed clinically relevant SWU compared to 26/116 patients undergoing adenosine stress (P = .020).

CONCLUSION

Patients on PPIs scheduled for vasodilator stress MPI may discontinue PPIs for 3 days, or replace with H2A to reduce the incidence of clinically relevant SWU associated with PPI therapy.

The effects of pharmacological interventions, exercise, and dietary supplements on extra-cardiac radioactivity in myocardial perfusion single-photon emission computed tomography imaging

Myocardial perfusion imaging (MPI) as an imaging modality plays a key role in the monitoring of patients with cardiovascular disease. MPI enables the assessment of cardiovascular disease, the effectiveness of therapy, and viable myocardial tissue. However, MPI suffers from some downfalls and limitations, which can influence its clinical applications. These limitations can arise from the patient's condition, equipment, or the actions of the technologist. In this review, we mainly focused on the different effective parameters on radioactivity uptake of organs including liver, intestines, stomach, and gall bladder and how they affect the quality of the acquired images in nuclear medicine. More importantly, we cover how different suggested medicines, foods and exercise alleviative this problem.

Increased Gastric Activity on Myocardial Perfusion Imaging

We anecdotally observed an increased accumulation of (99m)Tc-tetrofosmin in the stomach of myocardial perfusion patients when their uptake phase coincided with preparation of hamburgers in an adjacent room for gastric emptying studies on other patients. The potential for a scent-stimulated alteration of gastric biodistribution required further investigation.

METHODS

An experimental group and a control group were enrolled (20 patients per group). The experimental group could smell food being prepared during the uptake phase. Stomach, heart, and background regions were drawn in multiple projections, and the resulting data were evaluated.

RESULTS

The experimental and control groups did not significantly differ in stomach counts per pixel, background-corrected counts per pixel, or heart-to-stomach ratio. Further analysis of the data revealed that women had a significantly higher increase in stomach counts (P = 0.022) and background-corrected stomach counts (P = 0.018) than men.

CONCLUSION

Women had a greater increase in gastric (99m)Tc-tetrofosmin activity than men during the radiopharmaceutical uptake phase, but there was no causal relationship between an increase in activity and olfactory stimulation from the cooking of food.