Beyond Survival
A Cardiologist’s Perspective with Dr. Hwaida Hanoush
By: Lennard Goetze, Ed.D | Daniel Root | Regina Bessler, PhD
With a strong focus on women’s heart health, preventive cardiology, and individualized treatment strategies, Dr. Hannoush combines the rigor of traditional cardiovascular medicine with the systems-based insight of functional medicine. Her approach is rooted in uncovering the deeper drivers of disease rather than simply managing symptoms. At Precimed Clinic, that means using advanced diagnostics, nuanced interpretation, and personalized care plans to help patients understand the “why” behind their cardiovascular risk—and, where possible, reverse it.
But in a recent discussion about cancer rehabilitation and survivorship, Dr. Hannoush turned her attention to a topic that remains dangerously under-recognized in mainstream medicine: the cardiovascular consequences of cancer therapy. Her message was clear, urgent, and clinically significant: for many cancer survivors, the battle does not end when the tumor is gone.
The Overlooked Crisis in Cancer Survivorship
Much of the public conversation around cancer treatment centers on remission, recurrence, and tumor response. But according to Dr. Hannoush, there is another threat quietly affecting survivors long after treatment has ended: cardiovascular injury. “I want to highlight,” she said, “that for many cancer survivors, cardiovascular side effects of chemotherapy become a serious — and often unrecognized — long-term threat.” That observation reframes the survivorship conversation in an important way.
While cancer therapies are often life-saving, many of them can place profound stress on the cardiovascular system. These effects may not always be immediately visible, but over time they can contribute to heart failure, arrhythmias, coronary disease, vascular dysfunction, metabolic injury, and long-term decline in physical resilience. Research shows that as cancer treatments become more effective and survival extends, cardiovascular disease increasingly emerges as a dominant competing risk — underscoring why protecting the heart during and after cancer treatment is not optional, but essential.
This is the domain of cardio-oncology, an evolving field focused on protecting heart health before, during, and after cancer treatment. Dr. Hannoush has seen its importance firsthand, particularly through her previous work evaluating heart function in patients undergoing aggressive therapies.
She explained that this is not a fringe concern or a rare side effect. In many cases, cardiovascular complications become the dominant long-term health threat in cancer survivors, particularly when these patients are not proactively monitored. What sets Dr. Hannoush apart from many cardiologists is that she brings a second, complementary lens to this work: functional medicine. While cardio-oncology guidelines focus on monitoring heart function, managing cardiovascular risk factors, and intervening when damage is detected, functional medicine asks a deeper upstream question — why is this particular patient’s body uniquely vulnerable, and what can be done to strengthen its resilience before and after treatment begins? It is the integration of both frameworks that defines her approach to survivorship care.
Why the Heart Is So Vulnerable
One of the strengths of Dr. Hannoush’s perspective is her ability to explain cardiac injury not as a single event, but as a multi-layered biological process.
According to her, chemotherapy and related treatments can harm the cardiovascular system through several overlapping mechanisms. First, some drugs can cause direct injury to the myocardium, the muscular tissue of the heart itself. Others disrupt the mitochondria, the energy-producing structures that are especially abundant in cardiac tissue. “The heart is rich in mitochondria,” she explained, “which is the power source.”
When mitochondrial function is impaired, the heart may continue beating, but
it does so with reduced cellular efficiency and diminished reserve. Research
confirms that drugs like doxorubicin cause mitochondrial oxidative stress,
impaired energy production, and accelerated cell death in cardiac tissue — and
that a patient’s individual mitochondrial biology can influence how vulnerable
their heart is to this damage, pointing toward a future of more personalized
cardiac risk assessment.
Cancer treatments can also affect the coronary arteries, promoting atherosclerosis and increasing the risk of infarction or heart attack. At the same time, they may alter glucose regulation, insulin sensitivity, lipid metabolism, oxidative stress, and inflammatory burden—all of which increase cardiovascular risk even further.
Dr. Hannoush also emphasized the role of hormonal disruption, especially in therapies that suppress sex hormones. In both women and men, these hormonal shifts can have significant effects on vascular function, metabolism, and heart health. And perhaps most compellingly, she pointed to a mechanism often left out of conventional oncology conversations: the gut-heart axis.
“Gut dysbiosis is a very important side effect of chemotherapy,” she said.
Because gut health influences inflammation, immune regulation, neurotransmitter
production, and metabolic stability, its disruption can have ripple effects far
beyond digestion. Emerging preclinical
evidence supports this concern: chemotherapy-induced gut dysbiosis can increase
intestinal permeability, allowing bacterial products to enter the bloodstream
and drive systemic inflammation that worsens cardiovascular injury — a pathway
now being studied as part of the gut-microbiota-heart axis. While direct proof
in humans is still developing, the mechanistic evidence is compelling and
growing.
One cardiovascular risk that
deserves particular mention — especially for readers who have undergone
treatment for breast cancer, Hodgkin lymphoma, or lung cancer — is radiation
therapy. When radiation involves the chest, it can damage the coronary
arteries, heart valves, and the pericardial sac through a process of chronic
inflammation and scarring. What makes this especially difficult to detect is
that these effects can remain silent for years or even decades after treatment
ends. Long-term survivors who received chest radiation as recently as their
twenties or thirties may not see cardiovascular consequences until midlife —
making awareness and surveillance in this population critically important.
Taken together, these mechanisms reveal a difficult truth: many cancer treatments affect not only the tumor, but the body’s foundational systems of resilience.
The Problem with Waiting Too Long
A major concern for Dr. Hannoush is that conventional monitoring often catches cardiovascular damage too late. Traditionally, clinicians look for a decline in ejection fraction (EF) ― a measure of how much blood the heart pumps out with each beat. But by the time EF drops, injury may already be well underway.
That is why she strongly advocates strain imaging, a more sensitive technique that evaluates subtle deformation in the heart muscle before overt dysfunction appears. “You don’t want to wait till the heart function drops,” she explained. “You want to detect it earlier.”
This technology, commonly referred to as longitudinal strain, has become a valuable tool in cardio-oncology because it can reveal subclinical deterioration in the myocardium before symptoms emerge and before standard imaging appears abnormal.
For Dr. Hannoush, this represents one of the clearest examples of what precision medicine should look like in practice: not reactive care, but early detection, functional monitoring, and intervention before collapse. She also emphasized that such monitoring should not be sporadic or incidental. Oncology patients, she argued, should have structured cardiovascular protocols that include echocardiograms, biomarker tracking, and ongoing surveillance tailored to their treatment exposure.
Cancer Rehab Must Be More Than Physical Therapy
Another central theme in Dr. Hannoush’s discussion was the need to redefine what “rehabilitation” actually means after cancer treatment. From her perspective, true recovery is not limited to mobility or strength training. It must include the broader restoration of the systems that treatment may have disrupted—the heart, skeletal muscle, metabolism, hormones, nutrition, detoxification pathways, and even the microbiome.
She specifically highlighted skeletal muscle as a major but often neglected player in survivorship. “Muscles are very important,” she said, noting that skeletal muscle functions as a kind of metabolic organ. It helps regulate insulin sensitivity, glucose uptake, and systemic energy balance. When cancer treatment contributes to muscle loss or frailty, the patient does not just become weaker—they become metabolically more vulnerable. What is perhaps most striking is that this vulnerability extends directly to the heart itself. Research shows that chemotherapy-induced muscle wasting can involve the myocardium — a phenomenon known as cardiac wasting — which thins the ventricular wall, raises cardiac stress, and can contribute to arrhythmias and heart failure independently of the direct toxic effects of the drugs. Protecting skeletal muscle and protecting the heart, it turns out, are not separate goals.
That is one reason why she sees rehabilitation as something far broader than conventional exercise recovery. It must also include metabolic rebuilding, nutrient replenishment, and resilience restoration.
One Size Does Not Fit All
Perhaps the most defining principle in Dr. Hannoush’s philosophy is her insistence that no two patients should be treated as biologically identical. “One size does not fit all,” she said plainly. That statement applies not only to cancer treatment, but to what comes after it.
This is where Dr. Hannoush’s functional medicine training becomes most distinct. Standard cardio-oncology guidelines — supported by major cardiac societies — focus on monitoring ejection fraction and strain, managing blood pressure and cholesterol, and initiating medications when cardiovascular risk is identified. These are essential and evidence-based. But functional medicine, as practiced by Dr. Hannoush, asks what lies beneath those numbers: What is this patient’s individual metabolic reserve? How are they processing and eliminating the chemical burden of treatment? What nutritional or hormonal imbalances are amplifying their vulnerability? These questions, she believes, are just as important as the clinical measurements and often go unasked.
In her view, survivorship care should be personalized using tools such as:
- Nutrigenomics
- Pharmacogenomics
- Metabolomics
- Advanced nutrient and functional testing
- Individualized detoxification assessment
- Cardiovascular and metabolic monitoring
This is especially important because two patients can receive the same therapy and emerge with dramatically different outcomes depending on their baseline reserves, detoxification capacity, nutrient status, hormonal balance, and metabolic health. “It’s not only about the outside toxins,” she noted. “Chemotherapy is one of the toxins, of course. And you need to know how your body is able to detoxify.”
That perspective — grounded in functional medicine’s core principle of identifying root causes rather than managing symptoms — broadens the survivorship conversation in an important way. Rather than viewing side effects as unavoidable collateral damage, Dr. Hannoush challenges clinicians to ask a more useful question: what can be measured, supported, and personalized before the damage becomes permanent?
An Awareness Gap That Must Be Closed
Dr. Hannoush also noted that the field still carries significant blind spots — and that women are among those most affected by them. Sex and racial differences in how cancer therapies damage the heart remain poorly understood, and most foundational cardio-oncology research has not been designed with these differences in mind. Women who have undergone treatment for breast cancer — many of whom received anthracycline-based chemotherapy, HER-2 inhibitors, aromatase inhibitors, or chest radiation represent a large and growing population of survivors with elevated cardiovascular risk. Yet the evidence base to guide their care remains incomplete. For readers of this publication, that gap is not abstract: it is personal. Advocating for thorough cardiovascular surveillance after cancer treatment is not overcaution: it is self-knowledge
Despite the growing evidence in support of cardio-oncology and personalized survivorship care, Dr. Hannoush believes one of the greatest barriers is still lack of awareness. Many patients are never fully informed about what to watch for after treatment. Some assume that once chemotherapy is complete, the danger has passed. Others may not connect symptoms like fatigue, exercise intolerance, palpitations, weight gain, or metabolic instability to prior treatment exposure.
That silence, she suggests, is part of the problem. For now, she believes the most realistic first step is not perfection—it is education. “Raising awareness will be good as a start,” she said.
That awareness must extend to patients, caregivers, oncologists, cardiologists, and the broader rehab community. Because if survivorship is truly the goal, then medicine must stop measuring success only by tumor shrinkage and begin asking a more complete question:
What did the treatment save—and what did it cost? In that conversation, Dr. Hwaida Hannoush offers a voice that is both scientifically grounded and clinically humane. Her work reminds the medical world that surviving cancer should not mean silently inheriting a second chronic disease.
If precision medicine is truly the future, then survivorship care must become just as precise.
