“Alone we can do so little, together we can do so much.” Helen Keller
The links between kidney disease and cardiovascular disease have been reported as far back as 1827 with Richard Bright describing the changes in the left ventricle associated with kidney disease, and subsequently, Frederick Akbar Mahomed reporting increased arterial stiffness in patients with Bright’s disease.1 Over the last two to three decades it has become increasingly apparent that kidney disease is the most important predictor of outcomes in all cardiology diseases and that cardiovascular disease is the leading cause of death in patients with chronic kidney disease.2 In 2008, a systematic approach to the bi-directional interactions of heart and kidney diseases, or cardiorenal syndromes (table 1), was proposed.3 Cardiorenal syndromes can be broadly defined as disorders of the heart and kidney whereby acute or chronic dysfunction in one organ can induce acute or chronic dysfunction in the other.4 This was followed by increasing efforts to develop strategies to manage patients with combined heart and kidney dysfunction, as demonstrated by an increasing number of publications on cardiorenal syndromes.5
Table 1. The cardiorenal syndromes
| Type | Denomination | Description |
|---|---|---|
| 1 | Acute cardiorenal syndrome | Sudden worsening of heart function leading to acute kidney injury |
| 2 | Chronic cardiorenal syndrome | Chronically abnormal heart function leading to chronic kidney disease |
| 3 | Acute renocardiac syndrome | Acute kidney injury leading to acute heart function abnormalities |
| 4 | Chronic renocardiac syndrome | Chronic kidney disease contributing to abnormal heart function, left ventricular hypertrophy and increased risk of cardiovascular events |
| 5 | Secondary cardiorenal syndrome | Systemic disease (e.g. amyloidosis) leading to both heart and kidney dysfunction |
Subsequently, there have been calls for cardiologists and nephrologists to work together to optimise the care delivered to ‘cardiorenal’ patients.4-6 Because patients with kidney disease are almost invariably excluded from large cardiovascular clinical trials, the evidence base to guide management is sadly deficient. Closer collaboration between nephrologists and cardiologists has been advocated as a potential mechanism to advance clinical research into the pathological basis and optimal management of cardiorenal syndromes.4
Obstacles
There have traditionally been obstacles to closer collaboration between specialities. Historically, typical cardiology training has never really focused on diseases outside of the heart and great vessels.5 Although a more general medical education has long been part of nephrology training, inadequate attention has been given to cardiovascular disease, given its importance in the morbidity and mortality associated with chronic kidney disease.7 Trainee physicians are generally orientated towards specialities rather than patient-specific problems, leading to a potential ‘adversarial’ mentality.7 Furthermore, nephrologists and cardiologists are often consulted for specific questions or procedures, such as the initiation of dialysis or cardiac catheterisation, with little thought given to the holistic care required by a patient with cardiorenal syndrome.8
Need for collaboration
Complex cardiorenal syndromes need the application of knowledge of complex pathophysiology and pharmacology, familiarity with haemodynamic assessments, the skilled use of laboratory and imaging examinations, and the use of invasive procedures.9 These skills are seldom, if ever, present in a single physician.
Therefore, the authors of a short report in this issue of the British Journal of Cardiology (see Sankaranarayanan et al.) are to be congratulated for their efforts to set up a regular multi-disciplinary team meeting to manage patients with cardiorenal syndromes. They have organised, in a sustainable manner, cardiologists, nephrologists and clinical nurse specialists to work together delivering improved, cost-effective treatments to complex patient-centred issues.
Indeed, the creation of dedicated interdisciplinary cardiorenal teams has been advocated as an essential step in the management of patients with cardiorenal syndromes focusing on core outcome measures based on patient and physician priorities.6 These collaborations could also oversee cross-training among cardiology and nephrology trainees, as well as nursing and allied healthcare professionals in both specialities. The evolution of a new cardiorenal speciality has also been proposed, and the emergence of a new generation of cardiorenal specialists justified.4,5 However, with the ever-increasing advancements in both cardiology and nephrology, as well as the rising demands on trainees, we contend that increasingly closer working relationships between specialities may be a more realistic way forward, certainly in the short term. We also suggest that the management of patients with the ‘converse’ (type 4) form of cardiorenal syndrome, namely those patients with chronic kidney disease who develop uraemic cardiomyopathy, often in conjunction with significant coronary artery disease, pose equally complex treatment decisions that would benefit from a multi-disciplinary approach.
The value of close multi-disciplinary working seems almost self-evident, but it is a time-consuming and expensive undertaking, requiring the input of large numbers of staff who are removed from direct patient care for each meeting. It seems reasonable to call for closer evaluation of the value of this approach in cardiorenal disease from much larger datasets than the authors of this short report can currently provide. Eventually, the concept of choosing management strategies by multi-disciplinary team meeting, rather than by individual clinicians, in areas of clinical medicine where multiple options exist and complex decision-making is required should be evaluated by randomised clinical trials. In the meantime, we support the concept of the development of ‘cardiorenal teams’ and look forward to future publications in this area. If Helen Keller could overcome being deaf and blind to earn a Bachelor of Arts degree and become a distinguished lecturer and author, cardiologists and nephrologists should be able, at the very least, to overcome our differences and work together to achieve more for our patients.
Conflicts of interest
None declared.
Funding
This work was supported by British Heart Foundation Clinical Research Training Fellowships [FS/19/16/34169 to JP, FS/18/29/44554 to LP].
Editors’ note
Also see the article by Sankaranarayanan et al. in this issue.
References
1. Ferro CJ, Steeds RP, Townend JN. Hypertension, arterial haemodynamics and left ventricular disease: historical observations. QJM 2012;105:709–16. https://doi.org/10.1093/qjmed/hcs059
2. Moody WE, Edwards NC, Chue CD, Ferro CJ, Townend JN. Arterial disease in chronic kidney disease. Heart 2013;99:365–72. https://doi.org/10.1136/heartjnl-2012-302818
3. Ronco C, Haapio M, House AA, Anavekar N, Bellomo R. Cardiorenal syndrome. J Am Coll Cardiol 2008;52:1527–39. https://doi.org/10.1016/j.jacc.2008.07.051
4. Zannad F, Rossignol P. Cardiorenal syndrome revisited. Circulation 2018;138:929–44. https://doi.org/10.1161/CIRCULATIONAHA.117.028814
5. Ronco C, Ronco F, McCullough PA. A call to action to develop integrated curricula in cardiorenal medicine. Blood Purif 2017;44:251–9. https://doi.org/10.1159/000480318
6. Rangaswami J, Bhalla V, Blair JEA et al. Cardiorenal syndrome: classification, pathophysiology, diagnosis, and treatment strategies. A scientific statement from the American Heart Association. Circulation 2019;139:e840–e878. https://doi.org/10.1161/CIR.0000000000000664
7. Agrawal V, Agarwal M, Ghosh AK, Barnes MA, McCullough PA. Identification and management of chronic kidney disease complications by internal medicine residents: a national survey. Am J Ther 2011;18:e40–e47. https://doi.org/10.1097/MJT.0b013e3181bbf6fc
8. Agrawal V, Ghosh AK, Barnes MA, McCullough PA. Perception of indications for nephrology referral among internal medicine residents: a national online survey. Clin J Am Soc Nephrol 2009;4:323–8. https://doi.org/10.2215/CJN.03510708
9. Agrawal V, Ghosh AK, Barnes MA, McCullough PA. Awareness and knowledge of clinical practice guidelines for CKD among internal medicine residents: a national online survey. Am J Kidney Dis 2008;52:1061–9. https://doi.org/10.1053/j.ajkd.2008.06.022
