The role of hemodynamic limitations in the reduction of exercise capacity in patients with sarcoidosis

Aim: To perform comprehensive evaluation of the Cardiopulmonary Exercise Testing (CPET) parameters with gas analysis in patients with pulmonary sarcoidosis (PS) and to assess the effects of hemodynamic limitations on the reduction of exercise capacity (EC).

Materials and methods: We examined 42 PS patients (25 men, 17 women) aged from 22 to 62 years (34.5 [29; 41.5] years old). PS had been verified histologically in 33 (78.6%) patients. The group 1 included patients with decreased oxygen consumption per minute at the peak load (n = 20) with VO₂ peak pred ≤ 84%, i.e. with decreased EC. Group 2 consisted of 22 patients with normal VO₂ peak pred (> 84%). In all patients, echocardiographic and CPET parameters were assessed that characterize response of the cardiovascular system to physical exercise, such as oxygen consumption at the anaerobic threshold (VO₂ AT, % of predicted value); oxygen pulse (VO₂/HR, abs/% of predicted), the chronotropic-metabolic index (CMI), and blood pressure.

Results: Thickening of the left ventricular posterior wall (p = 0.012) was found in the group 1, together with decreased VO₂ AT (р < 0.001), VО₂/HR (р < 0.001), and systolic blood pressure (p = 0.037) at the peak load during CPET, compared to the parameters in the group 2. Twelve patients from the group 1 demonstrated their VO₂ AT < 43%, 6 patients had decreased VО₂/HR < 80% of predicted, and 3 patients were diagnosed with the chronotropic incompetence phenomenon.

Conclusion: Decreased EC was identified by CPET in 47.6% of PS patients without any functional abnormalities at rest. The reduction of EC in 17/20 PS patients from the group 1 was associated with abnormalities in CPET parameters, corresponding to the hemodynamic limitations (reduction of cardiac output and chronotropic incompetence).