The Impact of Nitroglycerin on the Evaluation of Coronary Stenosis in Coronary-CT: Preliminary Study in 131 Patients

Background: The sublingual administration of short-acting nitroglycerin (NTG) before coronary computed tomography (CCT) improves the visualization of coronary arteries, causing vasodilatation. The aim of this study was to evaluate whether and how nitroglycerin can influence the concordance between radiologists and cardiologists in the evaluation of vessel stenosis measured in CCT by the former and during the following coronarography by the latter. Methods: We conducted a retrospective analysis of 131 patients who underwent CCT for cardiac symptoms in 2022, followed by coronarography performed six months later because of significant stenosis revealed by the CCT. First, the patients were divided into two groups: an NTG group who received sublingual nitroglycerin before CCT and a non-NTG group who did not because of contraindications. Second, 254 stenoses were measured by two radiologists after CCT and by two interventional cardiologists during the next coronarography; moreover, stenoses were classified on the basis of their location and plaque pattern (calcific, mixed and lipidic). Third, the strength of agreement was evaluated between the two radiologists, between the two cardiologists and finally between the radiologists and cardiologists in order to evaluate whether and how the interdisciplinary discrepancy in stenosis evaluation could change with or without the use of nitroglycerin before CCT and in relation to the different plaque pattern. Results: In the NTG group, the use of nitroglycerine reduced the agreement between radiologists and cardiologists in calcific stenosis but did not change the concordance in the case of mixed or lipidic plaques on the same vessels. Conclusions: The use of sublingual nitroglycerin before CCT may lead to a radiological overestimation of calcific stenosis.