JACC Cardiovasc Interv. 2026 Jul 13;19(13):1748-1762. doi: 10.1016/j.jcin.2026.04.014. Epub 2026 May 11.
ABSTRACT
BACKGROUND: Nitrates remain a key drug class in the management of angina pectoris. However, their effect on coronary blood flow has never been convincingly demonstrated in humans.
OBJECTIVES: The aim of this study was to assess the impact of sublingual nitroglycerin (NTG) on absolute coronary blood flow, coronary resistance, and left ventricular work.
METHODS: A randomized, double-blind, placebo-controlled, mechanistic study was conducted. Forty patients with suspected angina underwent cardiac catheterization and randomization to sublingual NTG (n = 20) or a placebo control (n = 20). Using continuous intracoronary thermodilution, baseline absolute coronary blood flow (the primary outcome) and a range of other hemodynamic parameters were measured. Following delivery of the sublingual intervention, repeat measurements were made after 5 and 10 minutes. Between-group differences were analyzed using analysis of covariance.
RESULTS: Sublingual NTG resulted in a significant decrease in mean left ventricular end-diastolic pressure of 38.1% (95% CI: 21.8%-54.4%) (estimated mean difference -5.4 mm Hg; 95% CI: -7.8 to -3.1 mm Hg; P < 0.001), along with significant decreases in aortic pressure of 8.5% (95% CI: 5.3%-11.7%) (estimated mean difference -8.6 mm Hg; 95% CI: -12.2% to -5.1%; P < 0.001) and distal coronary pressure of 7.4% (95% CI: 3.7%-11.1%) (estimated mean difference -7.1 mm Hg; 95% CI: -10.6 to -3.7 mm Hg; P < 0.001) after 10 minutes. Myocardial work also decreased by 21.1% (95% CI: 15.4%-26.9%) (estimated mean difference -8.9 mm Hg · s; 95% CI: -11.6 to -6.2 mm Hg · s; P < 0.001). Despite inducing a significant increase in vessel volume, NTG resulted in a significant increase in microvascular resistance of 8.0% (95% CI: 1.1%-14.9%) (estimated mean difference 121.5 Wood units; 95% CI: 15.3-227.8 Wood units; P = 0.026) and a corresponding decrease in absolute coronary blood flow of 13.3% (95% CI: 6.4%-20.2%) (estimated mean difference -8.7 mL/min; 95% CI: -13.4 to -3.9 mL/min; P = 0.001).
CONCLUSIONS: Sublingual NTG induced a significant decrease in left ventricular preload and afterload, resulting in a marked decrease in myocardial work. This was associated with a significant and adaptive decrease in absolute coronary blood flow.
PMID:42442890 | DOI:10.1016/j.jcin.2026.04.014
