Cardiovascular reserve and risk profile of postmenopausal women after chemoendocrine therapy for hormone receptor--positive operable breast cancer.

Purpose. To examine cardiovascular function and risk profile of postmenopausal women treated with chemoendocrine therapy (CET) for hormone receptor-positive operable breast cancer. Methods. Forty-seven breast cancer patients and 11 age-matched healthy controls were studied. Participants performed a cardiopulmonary exercise test with expired gas analysis and impedance cardiography to assess peak aerobic power (VO(2peak)) and cardiovascular function (stroke volume, cardiac output, cardiac power output, and cardiac reserve). Traditional (i.e., body mass index, lipid profile, and fasting insulin and glucose) and novel (i.e., C-reactive protein, brain natriuretic peptide) cardiovascular risk biochemical factors were also assessed. Results. Breast cancer patients had significantly lower peak exercise stroke volume (68 +/- 9 versus 76 +/- 11 ml/beat), cardiac output (10.4 +/- 1.5 versus 11.7 +/- 2.4 l/minute), cardiac power output (3.0 +/- 0.5 versus 3.5 +/- 0.9 Watts), cardiac power output reserve (1.7 +/- 0.6 versus 2.4 +/- 0.8 Watts), and VO(2peak) (1.3 +/- 0.3 versus 1.6 +/- 0.2 l x min(-1)) than control subjects (p-values < .05). Patients with the greatest impairment in VO(2peak) had the worse cardiovascular risk profile. Exploratory analyses revealed several differences in study outcomes between the 26 patients receiving hormonal therapy with tamoxifen (TAM) and the 21 patients receiving aromatase inhibitor (AI) therapy. Conclusion. Breast cancer patients treated with adjuvant CET have a significantly and markedly lower cardiorespiratory fitness and cardiac functional reserve compared with age- and sex-matched controls. AI therapy may be associated with a more unfavorable cardiovascular risk profile than TAM. Prospective studies are required to further investigate the clinical value of these findings.