Medicine today has become highly specialized, for better or for worse. In the UK, where I studied medicine, the general flow of treatment escalation is to first see a local general practitioner concerning all nonemergency medical concerns; the general practitioner will then decide whether there is a case for a specialist referral.
However, in countries like Malaysia, where I reside, government and private healthcare run in parallel, meaning that an individual can decide to receive care in either option. This is because the costs of private healthcare are not as prohibitively high as they are in some Western countries.
As a result of this arrangement, a patient who decides that he has heart problems can choose to see a private cardiologist without first needing a referral letter from a general practitioner. The advantage of this is that it cuts down waiting times; the downside is that the patient’s problem may not be cardiac-related at all.
Should patients be able to pick and choose any specialist (or subspecialist) they wish to see, as long as they can afford it? This is the million-dollar question in countries that have a low barrier to private specialist access.
Two Approaches to Optimizing Care
There are signs that medicine is moving away from the paradigm belief that increased specialization means better health care. In contrast, physicians are realizing that the key to optimizing care is to do so in concert with other physicians in a multidisciplinary setting.
“In the current days of the COVID-19 pandemic, the magic of communication has become clear,” de Man and Vonk-Noordegraaf wrote in the American Journal of Physiology-Lung Cellular and Molecular Physiology. “Suddenly, face-to-face meetings and scientific conferences needed to be replaced by virtual meetings and communication with fellow scientists, colleagues, and even family occurred all via the computer in the virtual space of the world wide web.”
The COVID-19 pandemic also reinforced how medical disciplines depend to some extent on each other. There are 2 examples that illustrate this. The first is when nonemergency surgeries in most hospitals had to be canceled because hospital beds were being used up by COVID-19 patients. In this case, the number of patients infected with COVID-19 inadvertently impacted the surgical disciplines, forcing them to take a back seat.
The second is the phenomenon of “long COVID”, which is a term coined to refer to signs and symptoms that persist even after the primary infection has ceased. It can also be used to refer to new signs and symptoms that arise shortly after a COVID-19 infection. These symptoms can often include non-lung pathology, such as headache, depression, hair loss, and sexual dysfunction.
The Various Systems Involved in PAH
The argument regarding the interconnectivity of medicine made by de Man and Vonk-Noordegraaf supports the importance of looking at pulmonary arterial hypertension (PAH) as a multisystem disease.
Let’s review the characteristics of PAH. The excessive remodeling of the pulmonary arterioles means the heart needs to adapt to increased pressure overload from the lungs. When the right ventricle can no longer adapt to these changes, right-sided heart failure occurs.
Read more about PAH etiology
In addition, pressure overload increases cardiac wall stress, resulting in the release of stress hormones and inflammatory cytokines. The sympathetic nervous system and the renin-angiotensin-aldosterone system are hence activated.
“In addition to abnormalities intrinsic to the heart, dysfunction of other organs and dysregulation of systemic factors greatly affect the development and consequences of heart failure,” Fujiu and colleagues wrote in Nature Medicine. “Our results demonstrate a dynamic interplay between the heart, brain and kidneys that is necessary for adaptation to cardiac stress.”
This means that what started out as the abnormal remodeling of lung tissue can eventually lead to strain on the heart, brain, and kidneys. In addition, studies have demonstrated that the liver can also be damaged by complications of pulmonary arterial hypertension.
“The dual vascular supply and high metabolic demand put the liver at high risk for circulatory injury from heart failure,” Nickel and colleagues wrote in Pulmonary Circulation. “Despite its significant impact on mortality and a close relationship to right-sided hemodynamics, liver dysfunction in PAH patients is likely underreported in clinical trials and large registries.”
Read more about PAH complications
In summary, when the heart can no longer adapt to increased pressure overload from abnormal lung tissue restructuring, right-sided heart failure occurs, which has a knock-on effect on various organs in the body. Hence, stopping disease progression to heart failure is key to maintaining the quality of life in patients with PAH.
A Return to Teamwork
The example of how PAH can be classified as a multisystem disorder demonstrates the importance of taking a closer look at cell-cell and organ-organ interactions.
Organs are rarely damaged in isolation; the incredible interconnectivity of the systems of the body means that a dangerous domino effect can take place when an organ is damaged beyond a threshold point, resulting in increased morbidity.
Since many diseases cut across medical disciplines, it is important for physicians of various disciplines to recognize the importance of working together in a multidisciplinary framework. Medical specialization can achieve synergistic results when specialists work together. Ultimately, it will be our patients who will most benefit from an open-minded willingness to cooperate across disciplines.
de Man FS, Vonk-Noordegraaf A. The magic of communication: the need to study organ and cell communication in pulmonary arterial hypertension-induced right heart failure. Am J Physiol Lung Cell Mol Physiol. 2021;321(3):L634-L636. doi:10.1152/ajplung.00291.2021
Fujiu K, Shibata M, Nakayama Y, et al. A heart-brain-kidney network controls adaptation to cardiac stress through tissue macrophage activation. Nat Med. 2017;23(5):611-622. doi:10.1038/nm.4326
Nickel NP, Galura GM, Zuckerman MJ, et al. Liver abnormalities in pulmonary arterial hypertension. Pulm Circ. 2021;11(4):20458940211054304. doi:10.1177/20458940211054304