1. Introduction
Angina is one of the common clinical diseases. It is caused by insufficient oxygen supply to the myocardium due to coronary artery stenosis caused by coronary sclerosis or coronary artery spasm. Therefore, reducing myocardial oxygen consumption and increases coronary blood flow and then restores the balance between supply and demand of ischemic myocardial oxygen, at the same time, the prevention and treatment of atherosclerosis also are the fundamentals of angina treatment. Nicorandil is a well-known antianginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines1. It shows an efficacy equivalent to that of classic antianginal agents. Nicorandil has also been applied clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis2,3. The mechanisms have been involved in the protective effects of Nicorandil in angina through either opening of adenosine triphosphate-sensitive potassium (K-ATP) channel or donation of nitric oxide (NO)4,5.
Coronary heart disease patients are usually accompanied by hypertension. When experiencing angina pectoris, the patients often had an increase in blood pressure. Clinically, when this happened, intravenous isosorbide mononitrate and nitroglycerin are used to prevent angina, and the same time to control blood pressure. We all know that isosorbide mononitrate and nitroglycerin have anti-angina pectoris and affect blood pressure related to its release of nitric oxide factor5. Similarly,Nicorandil administration also increases the level of NO through reaction of its nitrate group with sulfhydryl group in cells of vascular smooth muscle4. Therefore, we speculate that Intravenous Nicorandil may also affect blood pressure. The effect of Intravenous Nicorandil on angina is well established,but few reports demonstrated that Nicorandil may cause severe vasodilation and fall in blood pressure, the impact of Intravenous Nicorandil on blood pressure has not been investigated till now.
Therefore, the aim of the study was to investigate the effects of Intravenous Nicorandil on blood pressure and drug safety in patients with coronary heart disease.