Safety and Effects of Sublingual Nitroglycerin on Coronary Lumen Volume in Patients with Severe Aortic Stenosis

Background: Intravenous vasodilators are considered to be contraindicated in patients with severe aortic stenosis (AS) because of concern that they may precipitate life-threatening hypotension; however, the safety and the effect of sublingual nitroglycerin (NTG) given before computed tomography angiography (CTA) in patients with severe AS undergoing transcatheter aortic valve implantation (TAVI) is not well-known.

Objectives: To determine the safety and the effect of sublingual NTG on coronary lumen volume (V) in patients with severe AS.

Methods: Sixty-nine consecutive patients (79.1 ± 8.8, years) received 0.8 mg sublingual NTG prior to CTA and 70 patients (80.4 ± 8.1, years) did not receive NTG. Blood pressure was measured before and after the scan, as well as before discharge from CTA unit. Patients were excluded if they had hypotension, defined as arterial blood pressure

Results: Systolic blood pressure decrease from 157 ± 27 mmHg before the scan to 139 ± 28 mmHg after the scan (P = 0.0003) and still similar before discharge from CTA unit (140 ± 26 mmHg, P = 0.83). In 26 patients (38%) blood pressure decreased > 20 mmHg without causing any symptoms. Side effects include 6 cases (8.7%) of headache, 8 cases (11.6%) of mild dizziness, which alleviate without medical intervention. All patients were discharged home after CTA. Coronary lumen V was significantly higher in patients with NTG compared to patients without NTG (5.4 ± 1.3 ml vs. 6.0 ± 1.2 ml; retrospectively, P = 0.02).

Conclusion: Administration of sublingual NTG before coronary CTA in patients with severe AS undergoing TAVI is safe. NTG administration increases coronary lumen volume, which may improve the visibility of coronary arteries and the diagnostic performance of coronary CTA.