Microcirculation and Heart Failure

The idea of coronary microcirculation playing a role in the pathophysiology of heart failure dates from decades ago, with authors hypothesizing that structural and functional alterations in the coronary microcirculation could potentially contribute to heart failure. It is known that in a wide range of primary cardiomyopathies, from dilated to hypertrophic, there are pathological alterations in myocardial vasculature structure and function, playing a role in the clinical course of the disease. Needless to say, many patients with normal epicardial coronary arteries can suffer from coronary microvascular dysfunction, that could lead to a wide variety of clinical problems - from impaired functional capacity to stable and unstable angina, Takotsubo syndrome, myocardial infarction with normal coronary arteries and can also end up with either acute or chronic heart failure. Furthermore, nowadays, it has been recognized that pathophysiology of the heart failure with preserved ejection fraction (HFpEF) is mainly due to the myocardial microcirculatory impairment. In heart failure with reduced ejection fraction (HFrEF) neurohumoral mechanisms affecting the peripheral vasculature have been identified as important factors in the development and progression of heart failure, leading to unfavourable remodelling, and thus some of them being important treatment targets. Among many new clinical scenarios where both myocardial and peripheral microcirculation play an important role, raising field of implantable continuous flow assist devices opens many questions and implies better understanding of their effects of microcirculation, as they usually lead to the improvement of end organ dysfunction caused by previous heart failure, which is probably through the positive effects of peripheral microcirculation.