Short-term blood pressure variability as an indicator of the adaptive capacity of patients with chronic heart failure

The six-minute walk test (6MWT) allows to determine, in addition to the main parameters, the time of heart rate recovery (THRR), cardiac function, adaptation index (AI), which characterize the compensatory reserve of patients with chronic heart failure (CHF). At the same time, the significance of these parameters in patients taking beta-blockers for CHF is insufficiently studied, taking into account the negative chronotropic effect of drugs. In this regard, it is relevant to identify factors that can characterize the compensatory capabilities of a patient with CHF during 6MWT, not related to the calculation of heart rate.

To identify hemodynamic indicators of the adaptive capabilities of patients with CHF during paired 6MWT depending on their intake of beta-blockers.

Seventy-four patients with compensated CHF due to coronary heart disease and/or hypertension formed the main group, comprising 46 individuals who were taking beta-blockers, and a comparison group comprising 28 individuals who had not been taking beta-blockers for at least one month before 6MWT. All participants underwent Doppler echocardiography (DECG), paired 6MWT, with assessment of hemodynamic parameters before and after both the first and second test. AI, THRR, blood pressure variability (BPV) were calculated. Multivariate, correlation analyses, univariate analysis of variance were used.

There were no significant associations between adaptation characteristics and DECG parameters or functional class (FC) of CHF in patients of the main group. In the comparison group, the indicators of compensatory reserve were significantly and directly associated with left ventricular ejection fraction (LVEF), and inversely with FC CHF and cardiac cavity size. In both groups, a greater difference in systolic blood pressure between the end of the first and the beginning of the second 6MWT was significantly associated with a higher index of right ventricular systolic dysfunction (Tricuspid annular plane systolic excursion) and LVEF, as well as a smaller left ventricular size and mass, and a lower pulmonary artery systolic pressure in patients in the main group.

Systolic BPV, measured immediately after 6MWT and 20 minutes after its completion, can indirectly characterize the compensatory reserve in patients with CHF, regardless of their beta-blocker intake.