Cardiac Reinnervation Affects Blood Pressure And Cardiorespiratory Adaptation To Exercise After Heart Transplant

PURPOSE: To investigate the hemodynamic and cardiorespiratory adaptation to exercise in individuals with heart transplantation (HTx) with (CR group) versus without evidence of cardiac reinnervation (NOCR group). METHODS: Sedentary individuals with HTx (age = 45.5 ± 2.2 years; time elapsed since surgery = 6.7 ± 0.7 years) were allocated to the CR (N = 16) and NOCR (N = 17) group according to their heart rate response to cardiopulmonary exercise testing (CPX). 24-h ambulatory blood pressure (BP), carotid-femoral pulse wave velocity (PWV) and cardiorespiratory fitness were assessed before and after 12 weeks of a thrice-weekly exercise program (5 min of warm-up, 30 min of aerobic exercise, 1 set of 10-15 reps in 5 resistance exercises, and 5 min of cool-down). RESULTS: The CR group had reduced (P < 0.01) 24-h systolic/diastolic BP (7/9 mmHg), daytime systolic/diastolic BP (9/10 mmHg) and nighttime diastolic BP (6 mmHg) after training (Figure). The NOCR group reduced (P < 0.05) only 24-h (5 mmHg), daytime (5 mmHg) and nighttime (6 mmHg) diastolic BP after training. Hourly analysis showed that the CR group reduced systolic/diastolic BP for 10/21 hours, while the NOCR group reduced systolic/diastolic BP for only 3/11 hours (Figure). The CR group also improved both maximal oxygen consumption (10.8 %) and exercise tolerance (13.4 %) after training, but the NOCR group improved only exercise tolerance (9.9 %). PWV did not change in both groups. CONCLUSIONS: Greater improvements in ambulatory BP and maximal oxygen consumption in the CR than NOCR group. These results suggest that CR affects hemodynamic and cardiorespiratory adaptations to exercise training in individuals with HTx.Figure: Ambulatory blood pressure before (pre) and after (post) 12 weeks of exercise training. A: average 24-h, daytime and nighttime systolic and diastolic blood pressure. B: Hourly averages of systolic and diastolic blood pressures. 1: individuals with clinical evidence of cardiac reinnervation. 2: individuals without clinical evidence of cardiac reinnervation. Asterisks denote significant difference from pre-intervention in the same group (*: P < 0.05; **: P < 0.01; ***: P < 0.001). Dagger denotes significant difference from the CR group during the same period (+: P < 0.05).