Assessing the Value of Echocardiograms for Patients with Acute Myeloid Leukemia (AML) Receiving Anthracyclines

Background

AML is a life-threatening disease that requires prompt administration of anthracycline-based induction chemotherapy, particularly in younger adults. Prior to treatment initiation, patients (pts) undergo routine echocardiography (echo) screening to assess cardiac ejection fraction (EF) as a measure of induction tolerability, despite American Society of Clinical Oncology and National Comprehensive Cancer Center guidelines which state that only pts with prior cardiac disease or exposure to cardiotoxic drugs or radiation therapy require such evaluation This is costly to the health-care system and may be unnecessary. In this study, we assess whether the use of echo prior to anthracycline-based therapy in AML has a major effect on pt outcomes.

Methods

We reviewed clinical data on AML pts treated with anthracycline-based induction chemotherapy regimens at our institution from 2002-2014. EF was obtained by 2D echo prior to induction chemotherapy initiation. Charlson comorbidity index was used to evaluate comorbidities prior to therapy. A cox proportional hazard model was used to analyze the impact of baseline echo on overall survival, with p-values <.05 denoting significance.

Results:

Of the 120 pts included, 60 (50%) were female. At diagnosis, median age was 57 years (range, 23-85), white blood cell count (WBC) 8.9 x 10⁹/L (0.3-227), hemoglobin 9.1g/dL (4.7-13.8), platelets 85 x 10³ (8-277), bone marrow blasts 48% (14-95%). Cytogenetic risk categories per CALGB 8461 criteria: 12 pts (10%) were favorable, 63 (53%) indeterminate, and 41 (34%) unfavorable. Charlson morbidity index was > 1 in 23 pts (19%) and 50 (38%) were current or former smokers. All pts received induction chemotherapy with either idarubicin (38%), daunorubicin (38%), or mitoxantrone (23%) combined with cytarabine (7+3). In 116 pts (97%), the baseline echo showed a left ventricular ejection fraction (LVEF) >50% (+/- 5). In the 4 remaining pts (3%), the EF was < 40%. In a multivariable analysis controlling for age, WBC, cytogenetic risk group, Charlson comorbidity index, and smoking exposure, LVEF was not associated with overall survival (HR 1.05 with 95% CI 0.99-1.12 and p=.09). Among the 4 pts with EF<40% (age 57-71 years), all received full dose anthracycline and only the 71-year-old patient experienced congestive heart failure during treatment. Six pts (5%) died during induction therapy (4 weeks) and none of these had an EF <40%.

Conclusion

Among AML pts who received anthracycline-based induction chemotherapy, results from echocardiography did not impact outcome in >99% in this cohort. It is not clear that echocardiography, particularly in younger pts, provides value, and may delay treatment initiation.