Apathy as a possible factor of cardiopulmonary exercise test efficiency in older patients with cardiovascular disease

Abstract Introduction Depression and cardiovascular diseases share overlapping risk factors, including biological and behavioral mechanisms, which contribute to comorbidity and worsened prognosis. Apathy, often observed in late-life depression, is characterized by indifference or flattened affect, reduced goal-directed behavior, and a lack of intellectual interest. Purpose This study aimed to evaluate the impact of apathy on peak oxygen uptake (peak VO2) during the Cardiopulmonary Exercise Test (CPET) in older patients with cardiovascular disease (CVD). Methods CPET was performed on outpatients aged over 50 years diagnosed with CVD. Depressive symptoms were assessed using the 15-item Geriatric Depression Scale (GDS-15), which includes three specific questions for detecting apathy. Statistical analyses examined correlations between apathy scores and peak VO2, adjusting for age, body mass index (BMI), smoking status, gender, exercise habits, and hemoglobin concentration (Hb). Results Seventy patients (mean age 61.4 ± 6.9 years; 64.3% female) participated, with a mean BMI of 28.3 ± 4.5 kg/m² and mean peak VO2 of 24.0 ± 4.4 mL/kg/min. Apathy symptoms were present in 14 patients (20%). Patients exhibiting apathy had significantly lower peak VO2 (t(68) = 2.16, p = 0.034, 95% CI 0.21–5.29), as did those following an unhealthy diet (t(68) = -2.38, p = 0.02, 95% CI -4.49 to -0.04) and those with sedentary lifestyle (t(68) = -2.35, p = 0.022, 95% CI -4.59 to -0.38). Peak VO2 was negatively correlated with higher apathy scores (ρ = -0.30, p = 0.011), older age (r = -0.33, p = 0.006), and higher BMI (r = -0.37, p = 0.002). No significant correlations were found for gender, hemoglobin concentration, or smoking status. Conclusions Apathy, independent of depression diagnosis, appears to be a distinct symptom in older patients with CVD and may significantly impair exercise capacity and tolerance.