An analysis of data from the St. Jude Lifetime Cohort Study provides new insight into the risk of long-term diastolic dysfunction associated with cardiotoxic cancer therapies in adult survivors of childhood cancer.
New research from analysis of more than 3300 adult survivors of childhood cancer offers further insight into the effects of cardiotoxicity on long-term diastolic dysfunction.
Results of the study, which was an analysis of data from the St. Jude Lifetime Cohort Study, indicate prevalence of isolated diastolic dysfunction among adults who received cardiotoxic therapies for childhood cancer were low and suggest use of left ventricular (LV) longitudinal strain significantly increased the identification of diastolic dysfunction.1
“Overall, we determined that diastolic dysfunction in survivors, of whom 12.2% to 19.2% were grade III, is largely attributable to concurrent systolic function,” wrote investigators.1 “In contrast, only 2.2% of survivors at base-line and 4.6% with preserved [ejection fraction] at follow-up had evidence of diastolic dysfunction. Furthermore, LV [global longitudinal strain] significantly improved the identification of diastolic dysfunction in adult survivors with preserved [ejection fraction] largely treated with cardiotoxic therapy.”
In recent years, the long-term impact of potential cardiotoxicity associated with agents used as part of cancer treatments have emerged as a focal point for researchers in cardiology and oncology alike. An example of the growing emphasis on the importance of cardiooncology, the current study was led by Gregory Armstrong, MD, of St. Jude Children’s Research Hospital, a team of colleagues with the intent of exploring the impact of cardiotoxic therapies for childhood cancer on long-term cardiovascular health, specifically diastolic dysfunction.1
With this in mind, investigators designed their study as an analysis of the landmark St. Jude Lifetime Cohort Study (SJLIFE). Launched in 2007, SJLIFE was created with the intent of establishing a lifetime cohort of childhood cancer survivors to facilitate longitudinal clinical evaluation of health outcomes in aging adults surviving pediatric cancer.2 From SJLIFE, investigators obtained data related to 3342 survivors of childhood cancer who were at least 10 years or more from initial diagnosis for inclusion in the current study.1
This cohort had a median age at diagnosis of 8.1 (Q1-Q3, 3.6-13.7) years, a median age at first echocardiography evaluation of 30.1 (Q1-Q3: 24.4-37.0) years, and a median age at second echocardiography evaluation of 36.6 (Q1-Q3: 30.8-43.6) years. Among this cohort, 49.2% were treated with chest-directed radiation and anthracycline chemotherapy, 37.7% were treated with anthracycline chemotherapy but no chest radiation, 6.8% were treated with chest-directed radiation but no anthracyclines, and 6.3% without anthracycline chemotherapy or chest-directed radiation therapy.1
The primary outcome of interest for the study was presence of diastolic dysfunction, which was defined using 2016 American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACI) guidelines. Of note, investigators further classified diastolic dysfunction according to severity.1
Upon analysis, results indicated the proportion of diastolic disunion was 15.2% (95% confidence interval [CI], 14.0-16.4) at the first echocardiography evaluation and 15.7% (95% CI, 13.9-17.7) at the second echocardiography evaluation, but investigators pointed out a large proportion of this was attributable to concurrent systolic dysfunction.1
Analysis of patient subgroups revealed less than 5% of survivors with preserved ejection fraction had diastolic dysfunction. Additionally, the inclusion of global longitudinal strain assessment in adult survivors with preserved ejection fraction, which was defined using a cutoff point of -15.9% or worse, indicated the proportion of diastolic dysfunction increased to 9.2% at baseline and 9.0% at follow-up.1
“The prevalence of isolated diastolic dysfunction is low among adults who received cardiotoxic therapies for childhood cancer. The inclusion of left ventricular global longitudinal strain significantly increased the identification of diastolic dysfunction,” wrote investigators.1