Pharmacists Are Key to Safer Cardio-Oncology Practice

Cardiovascular adverse events are among the most common and serious complications of cancer treatment, yet no comprehensive, unified clinical guidelines exist for assessing, monitoring, and mitigating cardiotoxicity.

To help fill this gap, a clinical review published in AJHP synthesizes the evidence on cardiotoxicity associated with select anticancer agents — and highlights opportunities for clinical pharmacists to improve the quality and safety of care.

The article, authored by Clement Chung, oncology clinical pharmacy specialist at Houston Methodist West Hospital in Texas, and Katelynn Tran, clinical pharmacist at Samaritan Health Services in Corvallis, Oregon, also explores important breakthroughs in the emerging field of cardio-oncology pharmacy.

ASHP News spoke with Chung to learn about clinical considerations for managing cardiotoxicity and the implications for clinical pharmacists.

The following interview has been edited for length and clarity.

ASHP: What inspired this research analysis?

Chung: There are many adverse cardiovascular events to be aware of when someone is receiving cancer therapy. We’re seeing more patients with both cancer and underlying cardiovascular disease.

Clinical pharmacy overlaps with cardiology and oncology. Cardio-oncology pharmacy is a growing field that could become a very good niche for clinical pharmacy practice.

Our paper summarizes mechanisms, clinical presentations, comparative assessments, and treatments of cardiotoxicity associated with major classes of anticancer drugs. We wanted clinical pharmacists to have this information in one place to guide clinical decision-making. We also wanted to help modernize how we manage cardiotoxicity in patients receiving cancer therapies.

Can you give some examples of cardiotoxicity?

Chung: Well-established oral targeted therapies like tamoxifen have a track record of venous thromboembolism. Another example is arsenic trioxide, the standard of care for acute promyelocytic leukemia (APL), which is well known to cause arrhythmia.

CAR T-cell therapy is much newer, and we’ve seen it can cause cardiomyocyte proliferation, hypertension, and arrhythmia — despite the low rates reported in clinical trials. Those patients should be closely monitored long-term for cardiotoxicities.

What do you think should happen next in this field?

Chung: Our study shows we’ve learned a lot about the mechanisms of drug-induced cardiotoxicity and how to reduce the risk of cardiotoxicity with specific therapies. But there is no single standard of care.

More work is necessary not only to improve clinical awareness of drug-induced cardiotoxicity but also to develop a more standardized, evidence-based approach to tailoring risk reduction with cardiotoxicity. Given the variations in current clinical guidelines and conflicting outcomes in the research literature, clinicians are often left to make care decisions based on anecdotal experience.

We need better definitions and better thresholds for what confers a significant risk. We need a validated algorithm to stratify patients’ cardiotoxicity risk based on age, cardiovascular history, and other factors, so we can identify those who may require time-sensitive interventions or long-term follow-up.

We also need to standardize monitoring frequencies. Going back to the example of arsenic trioxide for APL, recommendations for monitoring arrhythmia with an electrocardiogram (ECG) could be two times a week or three times a week for initial therapy (induction), depending on where you look. The recommended frequency for electrolyte monitoring is also inconsistent.

We can develop guidelines to reduce monitoring for patients who are at lower risk for cardiovascular disease. If a person has been receiving induction therapy with arsenic trioxide for over a month, their risk of QTc prolongation is minimal, and there has been no documented occurrence of arrhythmia, then that patient doesn’t need ECGs two to three times a week.

What surprised you about this research?

Chung: I was surprised that clinical trials have not been studying the long-term toxicity of anticancer drugs. Some complications, such as heart failure from anthracyclines, can take up to 10 years to develop. We need to take a proactive, longitudinal approach, and we need a lot more real-world data.

I was also surprised that we have not yet been able to use biomarkers to augment cardiotoxicity monitoring and detect cardiac damage early, even though much literature has been published in this area over the last 20 years.

Hopefully, these and other gaps will soon be addressed so we can do better for patients. As more cardiologists, oncologists, and pharmacists collaborate, we will gain more experience and knowledge.

What do you most want clinical pharmacists to know?

Chung: It’s important to take a baseline of a patient’s health before starting cancer treatment. Knowing their risk level will help determine cardiotoxicity monitoring and mitigation strategies.

Then, decide what the level of monitoring should be. In an otherwise healthy 40-year-old woman with breast cancer, there is not as much need to mitigate a very slight chance of cardiomyopathy. Compare that to an older patient with non-Hodgkin lymphoma whose regimen involves anthracyclines, for whom monitoring or proactive intervention is often necessary.

Inform your patients about potential cardiotoxicity. Involve them in surveillance of symptoms and address any reversible health factors.

Finally, consider when it’s appropriate to de-escalate anticancer therapy for the best outcomes. For example, if a patient has been on anticancer therapy for an extended period and they have a higher baseline for cardiovascular disease risk, you might need to extend the dosing interval (based on risk/benefit assessment of anticancer therapy), switch to less cardiotoxic alternatives, utilize liposomal formulations, or substitute therapy without a cardiotoxic-inducing agent.

What advice do you have for a clinical pharmacist who wants to advance their cardio-oncology practice?

Chung: The enormity of content in cardio-oncology is challenging, even intimidating. If you want to develop a robust program, the first step is to take one anticancer drug or class of drugs and make the cardiotoxicity intervention process structured, time-sensitive, goal-driven, and actionable. Develop surveillance, mitigation, and de-escalation strategies and gain buy-in from other clinicians.

Never give up, knowing it’s for the success of your practice and the safety of your patients.