Cardiovascular response to exercise in hypertension – clinical characteristics of ASSECURE study participants

Aim: Arterial hypertension leads to progressive cardiovascular dysfunction and heart failure. The aim of the study was to assess exercise capacity in hypertensives with the use of a cardiopulmonary exercise test, impedance cardiography and 6-minute walk test with special emphasis on haemodynamic response to exercise workload. Methods: 114 patients (53.5% women, 55.7 ± 9.1 years) were evaluated for reported symptoms, N-terminal pro-B-type natriuretic peptide (NTproBNP) levels, echocardiographic parameters and exercise capacity with 6-minute walk test, cardiopulmonary exercise test and haemodynamic parameters (by means of impedance cardiography). Results: 50% of patients had reported symptoms of impaired exercise tolerance, mostly dyspnoea on exertion (37.7%). NTproBNP levels exceeded 125 pg/mL in 19.3% of patients. Left ventricular diastolic dysfunction was found in 8.8% and heart failure was diagnosed in 6.2% of patients. A wide range of peak oxygen uptake (peak VO2) and 6-minute walk test distance was observed: 19.4 ± 5.2 mL/min/kg and 526.7 ± 112.0 m, respectively. A major proportion of patients demonstrated decreased exercise capacity parameters: 56.1% achieving peak VO2 < 22 mL/min/m2; 45.9% achieving peak VO2 < 80% of the predictive value; 37.3% achieving 6-minute walk test distance shorter than the predicted values. The impedance cardiography recorded at peak exercise: heart rate 147.2 ± 22.4 bpm, stroke volume 110.2 ± 21.8 mL, cardiac output 15.9 ± 4.2 L/min, peak systemic vascular resistance 587.4 ± 168.0 dyn.s/cm5. Conclusions: Although a very small proportion of patients with uncomplicated arterial hypertension meet the criteria for being diagnosed with heart failure, the symptoms of impaired exercise tolerance as well as abnormal results of objective exercise capacity assessments are quite common in these patients.