Left atrial strain in cardiac surveillance of bone marrow transplant patients with prior anthracycline exposure

Early Detection and Prediction of Anthracycline-Induced Cardiotoxicity - A Prospective Cohort Study

BACKGROUND

In the present study, we aimed to investigate whether early cardiac biomarker alterations and echocardiographic parameters, including left atrial (LA) strain, can predict anthracycline-induced cardiotoxicity (AIC) and thus develop a predictive risk score.

METHODS AND RESULTS

The AIC registry is a prospective, observational cohort study designed to gather serial echocardiographic and biomarker data before and after anthracycline chemotherapy. Cardiotoxicity was defined as a reduction in left ventricular ejection fraction (LVEF) ≥10 percentage points from baseline and <55%. In total, 383 patients (93% women; median age, 57 [46-66] years) completed the 2-year follow-up; 42 (11.0%) patients developed cardiotoxicity (median time to onset, 292 [175-440] days). Increases in cardiac troponin T (TnT) and B-type natriuretic peptide (BNP) and relative reductions in the left ventricular global longitudinal strain (LV GLS) and LA reservoir strain [LASr] at 3 months after anthracycline administration were independently associated with subsequent cardiotoxicity. A risk score containing 2 clinical variables (smoking and prior cardiovascular disease), 2 cardiac biomarkers at 3 months (TnT ≥0.019 ng/mL and BNP ≥31.1 pg/mL), 2 echocardiographic variables at 3 months (relative declines in LV GLS [≥6.5%], and LASr [≥7.5%]) was generated.

CONCLUSIONS

Early decline in LASr was independently associated with subsequent cardiotoxicity. The AIC risk score may provide useful prognostication in patients receiving anthracyclines.

Survivors of Pediatric Hematopoietic Stem Cell Transplantation Exhibit Progressive Diastolic Dysfunction Over Years of Follow-Up

Patients who have undergone hematopoietic stem cell transplantation (HSCT) in childhood have a higher risk of diastolic heart failure (HF). The rate of progression of diastolic dysfunction in aging pediatric patients is unknown and is more difficult to assess in young patients secondary to changes in diastolic indices as they grow. HSCT recipients at our center were previously found to have decline in diastolic function indices at 1 year after HSCT. This study provides follow-up of this cohort, using age-normalized z-scores to assess whether the decline in diastolic function noted at 1-year post-HSCT persists, worsens, or improves over time. Patients age <21 years who underwent HSCT at Boston Children's Hospital/Dana-Farber Cancer Center between 2005 and 2008 with ≥3 surveillance echocardiograms, including 1 performed pre-HSCT, were included. Diastolic measures included mitral inflow (E/A ratio) and Doppler tissue imaging of left ventricular lateral wall (LV lateral e'), LV septal wall (septal e') and right ventricular free wall (RV e'). Systolic function was measured by LV ejection fraction (LVEF). Normalization by age was done using z-scores, and >±2 SD was defined as abnormal in linear modeling of diastolic dysfunction and systolic dysfunction over time. In a subset of patients with adequate post-HSCT images of the entire left atrium (LA), LA volume and LA strain analyses also were performed. The study cohort comprised 61 patients (41% female; median age at HSCT, 10.7 years; median follow-up, 7.4 years). Diastolic index z-scores declined by -.045/year for LV lateral e', -.06/year for LV septal e', and -.14/year for RV e' (P < .01). The E/A ratio z-score increased by .034/year (P = .028). Linear modeling demonstrated that LV lateral e' and LV septal e' would become abnormal at 25 and 20 years post-HSCT, respectively, whereas RV e' would become abnormal sooner, at 12.6 years. LVEF z-score declined by -.04/year (P < .01) and was estimated to become abnormal at 40 years post-HSCT. Exposure to total body irradiation (TBI) was associated with worsening diastolic indices, lower LVEF (P ≤ .002), and decreased LA reservoir strain (42.0% versus 45.0%; P = .016) and conduit strain (-31.5% versus -35.1%; P = .029), although there was significant overlap between TBI and anthracycline exposure. Treatment with anthracyclines even at low doses (median, 150 mg/m2) was associated with declining LVEF but not with changes in diastolic indices. Long-term survivors of childhood HSCT exhibit declines in both LV and RV diastolic function indices. These results inform the rate of progression of LV and RV diastolic dysfunction indices over time in long-term survivors of pediatric HSCT. A significant association was observed between TBI and diastolic dysfunction and a decline in LVEF. Treatment with anthracyclines even at low doses was associated with a mild decline in LVEF. Our results can inform a lifespan perspective on disease management in this population, encourage clinicians and patients to be vigilant in following guideline-directed surveillance echocardiography, and inform anticipatory responses by clinicians as patients transition from pediatric care to adult care.