Nephrocardiology or Cardionephrology? Two Sides of the Same Medical Coin

In 1836, Richard Bright (1789–1858), the first of a series of outstanding physician–pathologists at Guy’s Hospital in London, noted that both cardiac hypertrophy and dropsy were common in patients with kidney disease [1].

The obvious structural changes in the heart (in patients with shrunken kidneys) consisted chiefly of hypertrophy, with or without valvular disease.

Five decades later, Goldblatt showed that the narrowing of both renal arteries, or even a single one, in a dog model induced a strong and prolonged increase in arterial pressure, with the subsequent onset of cardiac hypertrophy and vascular lesions [2].

These experimental findings are widely recognized as the pillars of modern cardionephrology. From this basis, the interactions between heart and kidneys were extensively investigated, resulting in the definition of the five cardiorenal syndromes (CRS) [3].

In this complex landscape, it is important to remember that around 40% of cardiorenal patients are diabetics, meaning that they thus realize the complex clinical presentation of so-called “cardiorenal metabolic syndrome”.

The recently updated 2022 Diabetes, Cardiorenal, and Metabolic (DCRM) multispecialty practice recommendations [4] were the first interdisciplinary consensus on the holistic management of patients with diabetes, cardiorenal, and/or metabolic diseases, providing evidence-based recommendations for interventions from lifestyle modifications to pharmacological treatment.

More recently, the American Heart Association reformulated the chronic cardiorenal syndromes into the new cardiovascular–kidney–metabolic syndrome [5]. The pathophysiology of this condition involves different and multidirectional pathways which have adverse effects on the vascular system, heart, and kidneys. The serious complications in patients with the syndrome include coronary disease, chronic heart failure, diabetes, and chronic kidney failure. Each of these conditions implies severe expenditures, and they are therefore becoming serious public health challenges.

Such a complex pathophysiology for the typical features of a disease leads to the need for particular treatment and integrated care, which might not be adequately addressed by either a cardiologist or nephrologist alone [6]. From the growing body of literature, it is clear that everywhere, independent of specific care settings, there is a real, unsatisfied need to take care of patients with simultaneous kidney and heart disease with a personalized, patient-centered approach that, in turn, must be based on the most recent cardiological and nephrological guidelines [7,8].

In actuality, in many countries, cardiologists primarily manage type 1 and 2 cardiorenal syndrome, while nephrologists primarily treat types 3 and 4. However, cooperation is crucial to prevent and manage CRS at various levels. Institutional collaboration should go beyond occasional consultations, as frequently occurs in current patient management. An integrated, simultaneous, multidisciplinary approach involving different medical specialties in CRS treatment is still lacking, leaving patients receiving partial or restricted care due to the limited point of view of a single specialty [9]. This is one of the reasons for the underdiagnosis of CRS, as in the case of around 40% of those currently in treatment, even whilst early detection is fundamental to delaying disease progression [10].

From these observations, cardionephrology, or nephrocardiology, emerge as new interdisciplinary specialties that allow patients to receive integrated, comprehensive care.

Moreover, the development of new drugs has provided important advances in the treatment of these patients, reducing adverse cardiac and renal outcomes.

The recent literature shows various attempts to work together across cardiac and nephrology departments. From the US [11] to Italy [12], several groups describe their coworking experience as a successful way to treat these patients, giving models and information for reducing complications and ameliorating quality of life.

In light of all these considerations, we are proud to launch this new journal with the aim of spreading knowledge about this interesting and evolving field of research. We believe that deeper, shared knowledge can be the basis for a more comprehensive, integrated model of care that, independently of the setting in which a patient is examined, can ensure that they receive the best multidisciplinary treatment possible.