Additive effects of nicorandil on coronary blood flow during continuous administration of nitroglycerin.
OBJECTIVE
We examined whether patients with ischemic heart disease (IHD) should be treated with nicorandil, an adenosine triphosphate-sensitive potassium channel opener, in addition to the regular use of nitrates.


BACKGROUND
It has been reported that nicorandil possibly has additive effects on nitroglycerin (NTG) treatment for angina, but the mechanism is not clear.


METHODS
We directly measured anterograde coronary blood flow (CBF) with a Doppler guide wire to examine the effects of intravenous administration of NTG (0.3 mg) and nicorandil (6 mg) during continuous administration of NTG at a sufficient dose (25 microg/min) in subjects with normal and stenotic coronary arteries.


RESULTS
Additional systemic administration of NTG decreased anterograde CBF (normal -19.7%; stenotic -21.2%). In contrast, nicorandil increased anterograde CBF in both normal (54.6%) and stenotic (89.6%) coronary arteries, without the coronary steal phenomenon. There was a tendency toward nicorandil-dilated diameters in the patients with stenotic arteries (p = 0.06). There were no effects of additional administration on pulmonary artery wedge pressure. There was no difference in changes in heart rate and mean aortic blood pressure between NTG and nicorandil therapy.


CONCLUSIONS
These results suggest that in patients treated with nitrates, additional administration of nicorandil is more useful, in terms of increasing CBF, than additional administration of nitrates. Adjunctive use of nicorandil with nitrates may provide the further benefit of myocardial protection and may improve the prognosis of patients with IHD.
Okamura
A
A
Department of Geriatric Medicine, Osaka University Medical School, Suita, Japan.
Rakugi
H
H
Ohishi
M
M
Yanagitani
Y
Y
Shimizu
M
M
Nishii
T
T
Taniyama
Y
Y
Asai
T
T
Takiuchi
S
S
Moriguchi
K
K
Ohkuro
M
M
Komai
N
N
Yamada
K
K
Inamoto
N
N
Otsuka
A
A
Higaki
J
J
Ogihara
T
T
D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D023921:Coronary Stenosis / Q000188:drug therapy* / Q000503:physiopathology; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020108:Nicorandil / Q000494:pharmacology* / Q000627:therapeutic use; D005996:Nitroglycerin / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use
D014665:Vasodilator Agents; D020108:Nicorandil; D005996:Nitroglycerin