Long-Acting Nitrate Single-Photon Emission Computed Tomography Myocardial Viability Study: A Serial Case Report

다국어 초록 (Multilingual Abstract)

Objective: A nitrate-augmented 99mTc-sestamibi cardiac single-photon emission computed tomography imaging protocol has been shown to improve detection of viable cardiac segments.
This protocol usually makes use of a short-acting nitrate and requires patients to stop prescribed long-acting nitrate medication for at least two days prior to the study. No previous studies have used long-acting nitrate in myocardial viability research.
Materials and Methods: Ten adult patients who had routinely used long-acting nitrate medication participated in this nitrate-augmented myocardial viability study. A long-acting nitrate was given one hour prior to 99mTc-sestamibi injection, and results were evaluated based on uptake changes after nitrate augmentation. Myocardial reversibility was assessed using visual scoring with a 17-segment model, with increased uptake ≥10% considered viable.
Results: Eight of 10 patients had a greater than 10% increase in uptake compared to baseline, and nine of 10 patients showed significant changes in sum rest score (SRS) and sum rest nitrate score (SRNS) p<0.001. In most patients, blood pressure dropped significantly after nitrate administration. One patient with no uptake changes or myocardial reversibility based on SRS and SRNS demonstrated increased blood pressure after nitrate administration.
Conclusion: Oral long-acting nitrates are a feasible option for nitrate-augmented myocardial viability studies. Patients on long-acting nitrate therapy who require myocardial viability study do not need to discontinue the medication prior to the study. Further evaluations with larger samples are needed to confirm these findings.