Administering Diltiazem before CCTA could improve image quality for heart transplant patients
Researchers at Duke University Medical Center have uncovered a drug that may make medical imaging safer for patients undergoing orthotropic heart transplants (OHT).
OHT patients must undergo routine computed tomography angiography (CCTA) to detect any changes or adverse events, such as coronary atherosclerosis and cardiac allograft vasculopathy (CAV), that may occur after surgery.
But these patients often have elevated heart rates, which makes obtaining diagnostically valuable scans a challenge. Heart rates should ideally sit below 75 beats per minute to reduce cardiac motion during CCTA. And the researchers believe Diltiazem can help.
“CAV can affect the long-term survival of individuals as it is likely associated with chronic graft failure and noted to have a morbidity rate of 7.7% within 1 year, and 46.8% within 10 years of transplantation,” corresponding author, Andrew Somers, with the Department of Radiology at Duke University Medical Center, and co-authors explained in the Journal of Radiology Nursing.
Beta blockers are commonly used during CCTA exams, but they do not always garner a physiologic response in OHT patients. Researchers at Duke hypothesized that Diltiazem, a calcium channel blocker, administered before CCTA may be a solution.
This theory was tested in 25 adult OHT patients undergoing CCTA. Heart rates were monitored by electrocardiogram (ECG) before and after the patients received Diltiazem, which allowed the experts to make a comparison.
The average baseline heart rate before medication administration was 84.28. After receiving Diltiazem via IV injection, that rate dropped to 75.32. Overall, heart rates dropped in 23 subjects, and 13 achieved the target heart rate of 75 bpm.
The authors noted that although the number of patients who reached the target heart rate was limited, the precise dosing of the medication could factor in and should be investigated more closely. They added that some patients could benefit from two doses rather than one, but further research involving the use of Diltiazem in OHT patients is warranted.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.