Abstract
BACKGROUND: Long-acting nitrates are widely prescribed in coronary artery disease (CAD), yet their association with long-term outcomes remains controversial. Whether left ventricular ejection fraction (LVEF) modifies this relationship has not been well characterized. METHODS: We conducted a single-center retrospective cohort study using the Guizhou Provincial People's Hospital CAD database. Adults (≥18 years) who underwent coronary angiography between July 2012 and September 2016 and met angiographic criteria for CAD (≥50% stenosis in ≥1 proximal epicardial coronary artery) were eligible if LVEF and discharge medications were available. Patients were stratified by LVEF (<45%, 45%-55%, >55%) and by discharge prescription of any nitrate (mononitrate or dinitrate). The primary endpoint was all-cause death. The secondary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. Kaplan-Meier methods and multivariable Cox regression were used to evaluate associations. RESULTS: Among 2,404 patients followed for 27.2 ± 13.5 months, 1,153 (48.0%) were discharged on nitrates. In the overall cohort, discharge on nitrates was not associated with all-cause death or MACE. In contrast, among patients with LVEF < 45%, nitrates at discharge were linked to higher cumulative incidences of all-cause death and MACE (log-rank P = 0.024 and 0.029, respectively) and remained independently associated after adjustment [all-cause death: hazard ratio (HR) 2.14, 95% confidence interval (CI) 1.15-3.96; MACE: HR 1.91, 95% CI 1.07-3.43]. No significant associations were observed in the LVEF 45%-55% or >55% strata. CONCLUSION: In this CAD cohort, nitrates were commonly prescribed at discharge. An adverse association with long-term outcomes was confined to patients with reduced LVEF, supporting cautious use in this subgroup and highlighting the need for prospective confirmation.