ACC 2009: Cancer Patients on Cardiotoxic Chemo Are Not Getting Proper Treatment for Heart Failure

Fran Lowry

March 29, 2009

March 29, 2009 (Orlando, Florida) - Cancer patients who develop left ventricular dysfunction from their chemo are not being referred to cardiologists for consultation, let alone treatment, particularly if their left ventricular dysfunction is asymptomatic, investigators reported here at the American College of Cardiology (ACC) 2009 Scientific Sessions.

Oncologists and cardiologists need to develop partnerships in the care of these patients so that they can continue to benefit from these chemotherapeutic agents without undue damage to their heart, said Dr Geoffrey Yoon (Stanford University, Palo Alto, CA).

In a retrospective analysis, all patients who received anthracycline or trastuzumab at Stanford between October 1, 2005 and October 31, 2007 were culled from a large pharmacy database. Of these, the 88 patients who had at least one echocardiogram before and after the start of chemotherapy were selected for extensive chart review to determine their heart-failure status and whether or not they received treatment or were referred to a cardiologist for consultation.

Their mean age was 52 years (range, 33 to 67), 41 were male and 47 were female, and 11 (13%) had a baseline left ventricular ejection fraction that was below normal (<55%). Cardiac risk factors were quite common in this group of patients.

Cardiac Risk Factors in 88 Patients

Risk factor n (%)
Coronary artery disease 6 (7)
Hypertension 28 (32)
Diabetes mellitus 15 (17)
Hypercholesterolemia 23 (26)
Cardiomyopathy 9 (10)

Thirteen percent of patients had a baseline ejection fraction that was below normal (<55%), and 41% had an ejection fraction that dropped below normal with chemotherapy. Most (75%) were asymptomatic, but 25% had symptoms of dyspnea, orthopnea, or edema.

Heart-Failure Treatment Inadequate

Many patients, whether symptomatic or not, did not get appropriate heart-failure therapy, nor were they referred to a cardiologist.

Percent of Patients Who Received Drug Therapy and Referral After Chemotherapy

Patients Received ACE-I/ARB Received beta blocker Referred to cardiologist
Asymptomatic, % 33 41 37
Symptomatic, % 47 56 50
ACE-I, ACE inhibitor; ARB, angiotensin-receptor blocker

“From a doctor's perspective, we need more protocols to screen patients after they get these therapies,” Yoon told heartwire . “The anthracyclines have been around for longer and it’s been known for a longer period of time that they can lead to heart failure, but there still are no significant protocols in place in terms of screening patients after they get anthracycline.”

One promising but expensive way to screen is with cardiac MRI. Biomarkers such as troponin and brain natriuretic peptide are also being explored, he said. ”Whatever we use, it is crucial to monitor patients during and after chemotherapy. Most patients get an assessment of their cardiac function before they go on chemo.”

Senior author of the study, Dr Ronald Witteles (Stanford University), told heartwire that ACC/American Heart Association guidelines stipulate the use of ACE inhibitors, angiotensin-receptor blockers, and beta blockers to treat heart failure. “It’s a level 1 recommendation for asymptomatic left ventricular dysfunction. And yet this is being ignored in this very vulnerable group of patients.”

And even when cardiac function returns to normal after treatment stops, there is no guarantee that the patient is home free in terms of heart failure, something that oncologists, in their zeal to use these life-saving chemotherapies, fail to appreciate, said Witteles.

Oncology Trials Stress Symptomatic Heart Failure

“Most oncology trials that look at cardiotoxicity place far more importance than most cardiologists and certainly most heart-failure specialists would on 'symptomatic heart failure' and pay very little attention to asymptomatic left ventricular dysfunction, which is something that cardiologists and certainly heart-failure specialists will take extremely seriously,” he said.

Even heart failure that is truly symptomatic can often be overlooked or mistaken for the side effects of chemotherapy. Fatigue, nausea, shortness of breath, and even edema can be easily attributable to adverse effects of cancer treatment, said Witteles

The investigators hope that their study will alert both specialties to the importance of close collaboration in monitoring heart function in patients undergoing chemotherapy.

Said Witteles: “The last thing we want to do as cardiologists is say that these wonderful life-saving drugs like [trastuzumab] should not be used because they damage the heart. Our goal is to make the chemotherapy safe--as safe as possible--and to minimize or eliminate the cardiotoxic effects.”

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