Japanese Herbal Medicine (Kampo) as a Possible Treatment for Ischemia With Non-obstructive Coronary Artery Disease

Patients presenting with the syndrome of symptoms and signs suggesting ischemic heart disease but found to have no obstructed coronary arteries (INOCA) are increasingly recognized. Although there are non-invasive tests for the diagnosis of INOCA, such as transthoracic Doppler echocardiography, positron emission tomography, and cardiac magnetic resonance imaging to evaluate increased blood flow with adenosine and other agents, the diagnosis of INOCA by coronary angiography with the coronary spasm provocation test and coronary microvascular function evaluation using pressure wires has become the gold standard, but it is not well established in the treatment of INOCA. Despite the lack of objection to lifestyle modification and the use of coronary dilators, mainly calcium-channel blockers, for conditions involving epicardial coronary artery spasm, there is no entirely effective long-term treatment for microvascular spasm or coronary microvascular dysfunction. Although some combinations of drugs have been empirically administered in certain cases, it is difficult to conclude that they are sufficiently effective. Recently, it has been reported that some Japanese herbal medicines (Kampo) have been effective in the treatment of INOCA. In order to increase the knowledge on the treatment of INOCA, this review focuses on the effects of Japanese herbal medicine on INOCA and its presumed mechanisms and problems.

Automated summary

Patients with symptoms of ischemic heart disease but without obstructed coronary arteries (INOCA) are increasingly recognized. The gold standard for diagnosing INOCA is coronary angiography with spasm provocation test and pressure wires for evaluating microvascular function. However, there is currently no well-established treatment for INOCA, especially for microvascular spasm or dysfunction. Japanese herbal medicine (Kampo) has shown promise in treating INOCA and this review focuses on its effects and potential mechanisms for this condition.