Left ventricular dysfunction in patients receiving cardiotoxic cancer therapies: Are clinicians responding appropriately?

Abstract

9527 Background: Cancer survivors treated with anthracyclines and/or trastuzumab are at risk for cardiotoxicity. Left ventricular (LV) systolic dysfunction (symptomatic or asymptomatic) represents a Class I indication for therapy with beta-blockers and angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) according to American College of Cardiology/American Heart Association heart failure guidelines. We designed this study to examine treatment practices for patients with cancer therapy-associated LV dysfunction, and the real-world adoption of treatment guidelines. Methods: After IRB approval, we identified all patients who received anthracycline and/or trastuzumab cancer therapy at Stanford University from October 1, 2005 to October 31, 2007 using an institutional pharmacy database. Out of 6,530 total cycles of chemotherapy administered, we identified all unique patients who had at least one echocardiogram performed before and after the start of chemotherapy using an institutional echocardiography database. Details of the chemotherapy regimen, cardiac risk factors, cardiac imaging results, concomitant medications, and referrals/consultations were examined for these patients. Results: A total of 88 patients met inclusion criteria. Ninety-two percent were treated with anthracyclines, 25% with trastuzumab in combination with anthracyclines, and 8% with trastuzumab alone. Mean baseline ejection fraction (EF) was 60%, with 13% of patients having a baseline EF below normal. A total of 41% had LV dysfunction (EF less than 55%) during or after cancer therapy. Of these patients, 56% received beta-blocker therapy, 47% received ACE-I or ARB therapy, and 50% were referred for cardiology consultation. Of the patients with asymptomatic LV dysfunction (75% of the LV dysfunction cohort), 41% received beta-blocker therapy, 33% received ACE-I or ARB therapy, and 37% received cardiology consultation. Conclusions: In real-world clinical practice, many cancer survivors with cardiotoxicity are not adequately evaluated and treated from a cardiovascular standpoint. Multidisciplinary collaboration between oncologists and cardiologists is needed to improve the quality of care for these patients. No significant financial relationships to disclose.