Vo2peak in Adult Survivors of Hodgkin Lymphoma: Rate of Decline, Sex Differences, and Cardiovascular Events

Abstract

BackgroundAdult survivors of Hodgkin lymphoma (HL) are at increased risk of cardiovascular (CV) events secondary to mediastinal radiation therapy (RT). ObjectivesIn this group of patients, we assessed the association between cardiopulmonary exercise testing (CPET), as determined by percent-predicted peak Vo2 (ppVo2peak), and clinical outcomes, as well as the rate of ppVo2peak decline and sex differences. MethodsAll survivors of HL who were >10 years post chest RT and who underwent ≥1 CPET were enrolled from a single center. Traditional CV and treatment risk factors, along with CV events, were ascertained. ResultsA total of 64 patients (67% female; median age 51 years [range 26 to 70 years]) with a median follow-up time after RT of 23 years (range 11 to 41 years), and 141 CPET studies, were included. Median initial ppVo2peak was 91% (range 58% to 138%). ppVo2peak in survivors declined by 7.5 percentage points every 10-year period after RT, as compared with age- and sex-based norms (P = 0.001), even after adjusting for hypertension and history of anthracycline. Both male and female patients had a similar rate of ppVo2peak decline. However, women had a lower ppVo2peak at all times, and they developed abnormal ppVo2peak (≤85%) on average earlier than men (24.1 years vs 47.0 years after RT). Patients with abnormal ppVo2peak vs normal ppVo2peak (>85%), had an increased risk of CV events (59% vs 16%). Abnormal ppVo2peak was independently associated with the risk of CV events (adjusted HR: 6.37; 95% CI: 2.06-19.80; P = 0.001). ConclusionsPercent-predicted Vo2peak in long-term survivors of HL who were treated with chest RT progressively declined as compared with population- and sex-based norms. Importantly, women developed abnormal ppVo2peak more than 2 decades earlier than male survivors. Abnormal ppVo2peak was associated with an increased risk of CV events in this group of patients.