(b) Effective treatments with lower level of evidence

Medication class	Example	Mechanism of action
Nitric oxide modulators	(i) L-arginine (ii) Sildenafil (iii) Cilostazol (iv) Tetrahydrobiopterin	(i) Vasodilation induced by nitrates through activation of the guanylyl cyclase signaling pathway (endothelium-dependent)
Hormonal drugs	(i) Estrogen	(i) Accelerating reendothelialization (endothelium-independent) (ii) Inhibiting endothelial cell apoptosis
	(ii) Vitamin D	(iii) Decreased vascular inflammation and improving endothelial function (endothelium-independent)
Novel antianginal	(i) Ivabradine	(i) Lowering heart rate and reducing myocardial oxygen demand
	(ii) Fasudil	(ii) Mediates vascular smooth muscle, endothelial, and inflammatory cell function
Miscellaneous	(i) PPI	(i) Inhibiting esophagocardiac reflex which leads to coronary vasoconstriction (endothelium-dependent)
	(ii) Metformin	(ii) Significant improvement in acetylcholine-stimulated flows (endothelium-dependent)
	(iii) SGLT inhibitors	(iii) Action on endothelium-not know yet (endothelium-dependent)
	(iv) Endothelin receptor antagonist	(iv) Decreasing vascular tone and causing vasodilation (endothelium-dependent)
	(v) Nicorandil	(v) Arterioles' smooth muscle relaxation (vi) Vasodilation through nitrate
	(vi) Imipramine	(vii) Elevating pain threshold
	(vii) Omega-3	(viii) Modifying inflammatory cytokine expression and inhibiting oxidative stress (endothelium-independent)
	(viii) Incretin	(ix) Endothelial nitric oxide synthase (eNOS) phosphorylation and increasing NO
	(ix) NAC	(xi) Modifying NO half-life and potentiates the activity of NO