Impact of ß-Blockers on Heart Rate and Oxygen Uptake During Exercise and Recovery in Older Patients With Heart Failure With Preserved Ejection Fraction.

PURPOSE: The study aimed to investigate the differences in oxygen uptake ((Equation is included in full-text article.)O2) and heart rate (HR) (at rest, submaximal exercise, peak exercise, and recovery) in patients with heart failure with preserved ejection fraction (HFpEF) with ß-blockers (BB) or without BB treatment (NBB) and to analyze the relationship between HR reserve (HRresv) and peak (Equation is included in full-text article.)O2 ((Equation is included in full-text article.)O2peak) in BB and NBB. METHODS: A total of 174 HFpEF patients (>65 yr; BB, n = 59; NBB, n = 115) were assessed with a cardiopulmonary exercise test to peak exertion using an incremental protocol. After 5 min of supine rest, HR and (Equation is included in full-text article.)O2 (HRrest, (Equation is included in full-text article.)O2rest) at submaximal exercise (HRsubmax, (Equation is included in full-text article.)O2submax), at peak exercise (HRpeak, (Equation is included in full-text article.)O2peak), at 1 min of passive recovery (HRrec1), HRresv (HRpeak- HRrest), and HR recovery (HRrecov = HRpeak- HRrec1) were evaluated. RESULTS: Analysis showed that HRrest (66.0 ± 12.2 vs 69.7 ± 10.6 bpm), HRsubmax (91.7 ± 16.2 vs 98.6 ± 15.2 bpm), and HRrec1 (102.9 ± 18.9 vs 109.4 ± 16.9 bpm) were significantly lower (P ≤ .05) in BB than in NBB, respectively. However, there were no significant differences (P > .05) between the BB and the NBB for HRpeak, HRresv, HRrecov, (Equation is included in full-text article.)O2rest, (Equation is included in full-text article.)O2submax, and (Equation is included in full-text article.)O2peak. A significant relationship was found between HRresv and (Equation is included in full-text article.)O2peak values in both groups (BB, r = 0.52; NBB, r = 0.49, P < .001). CONCLUSIONS: The nonsignificant differences in HRpeak, HRresv, HRrecov, or (Equation is included in full-text article.)O2 values between BB and NBB HFpEF patients, along with significant correlation between HRresv and (Equation is included in full-text article.)O2peak, suggest that these measures may have equal utility in prognostic and functional assessment as well as clinical applications, including the prescription of exercise, in elderly HFpEF patients.

Regional Adipose Distribution and its Relationship to Exercise Intolerance in Older Obese Patients Who Have Heart Failure With Preserved Ejection Fraction.

OBJECTIVES: This study sought to test the hypothesis that older obese patients with heart failure with preserved ejection fraction (HFpEF) have significantly greater abdominal, cardiac, and intermuscular fat than healthy, age-matched controls, out of proportion to total body fat, and that these abnormalities are associated with objective measurements of physical function. BACKGROUND: Recent studies indicate that excess total body adipose tissue contributes to exercise intolerance in patients with HFpEF. However, the impact of the pattern of regional (abdominal, cardiac, intermuscular) adipose deposition on exercise intolerance in patients with HFpEF is unknown. METHODS: We measured total body adiposity (using dual-energy x-ray absorptiometry) and regional adiposity (using cardiac magnetic resonance), peak oxygen uptake (Vo2), 6-min walk distance (6MWD), short physical performance battery (SPPB), and leg press power in 100 older obese patients with HFpEF and 61 healthy controls (HCs) and adjusted for age, sex, race, and body surface area. RESULTS: Peak Vo2 (15.7 ± 0.4 ml/kg/min vs. 23.0 ± 0.6 ml/kg/min, respectively; p < 0.001), 6MWD (427 ± 7 m vs. 538 ± 10 m, respectively; p < 0.001), SPPB (10.3 ± 0.2 vs. 10.9 ± 0.2, respectively; p < 0.05), and leg power (117 ± 5 W vs. 152 ± 9 W, respectively; p = 0.004) were significantly lower in patients with HFpEF than HCs. Total fat mass, total percent fat, abdominal subcutaneous fat, intra-abdominal fat, and thigh intermuscular fat were significantly higher, whereas epicardial fat was significantly lower in patients with HFpEF than in HC. After we adjusted for total body fat, intra-abdominal fat remained significantly higher, while epicardial fat remained significantly lower in patients with HFpEF. Abdominal subcutaneous fat, thigh subcutaneous fat, and thigh intermuscular fat:skeletal muscle ratio were inversely associated, whereas epicardial fat was directly associated with peak Vo2, 6MWD, SPPB, and leg power. Using multiple stepwise regression, we found intra-abdominal fat was the strongest independent predictor of peak Vo2 and 6MWD. CONCLUSIONS: In metabolic obese HFpEF, the pattern of regional adipose deposition may have important adverse consequences beyond total body adiposity. Interventions targeting intra-abdominal and intermuscular fat could potentially improve exercise intolerance. (Exercise Intolerance in Elderly Patients With Diastolic Heart Failure [SECRET]; NCT00959660).

Effects of supervised exercise and dietary nitrate in older adults with controlled hypertension and/or heart failure with preserved ejection fraction.

Aerobic exercise training is an effective therapy to improve peak aerobic power (peak VO2) in individuals with hypertension (HTN, AHA/ACC class A) and heart failure patients with preserved ejection fraction (HFpEF). High nitrate containing beetroot juice (BRJ) also improves sub-maximal endurance and decreases blood pressure in both HTN and HFpEF. We hypothesized that combining an aerobic exercise and dietary nitrate intervention would result in additive or even synergistic positive effects on exercise tolerance and blood pressure in HTN or HFpEF. We report results from two pilot studies examining the effects of supervised aerobic exercise combined with dietary nitrate in patients with controlled HTN (n = 26, average age 65 ± 5 years) and in patients with HFpEF (n = 20, average age 69 ± 7 years). All patients underwent an aerobic exercise training regimen; half were randomly assigned to consume a high nitrate-containing beet juice beverage (BRJ containing 6.1 mmol nitrate for the HFpEF study consumed three times a week and 8 mmol nitrate for the HTN study consumed daily) while the other half consumed a beet juice beverage with the nitrate removed (placebo). The main result was that there was no added benefit observed for any outcomes when comparing BRJ to placebo in either HTN or HFpEF patients undergoing exercise training (p ≥ 0.14). There were within-group benefits. In the pilot study in patients with HFpEF, aerobic endurance (primary outcome), defined as the exercise time to volitional exhaustion during submaximal cycling at 75% of maximal power output, improved during exercise training within each group from baseline to end of study, 369 ± 149 s vs 520 ± 257 s (p = 0.04) for the placebo group and 384 ± 129 s vs 483 ± 258 s for the BRJ group (p = 0.15). Resting systolic blood pressure in patients with HFpEF also improved during exercise training in both groups, 136 ± 16 mm Hg vs 122 ± 3 mm Hg for the placebo group (p < 0.05) and 132 ± 12 mm Hg vs 119 ± 9 mm Hg for the BRJ group (p < 0.05). In the HTN pilot study, during a treadmill graded exercise test, peak oxygen consumption (primary outcome) did not change significantly, but time to exhaustion (also a primary outcome) improved in both groups, 504 ± 32 s vs 601 ± 38 s (p < 0.05) for the placebo group and 690 ± 38 s vs 772 ± 95 s for the BRJ group (p < 0.05) which was associated with a reduction in supine resting systolic blood pressure in BRJ group. Arterial compliance also improved during aerobic exercise training in both the HFpEF and the HTN patients for both BRJ and placebo groups. Future work is needed to determine if larger nitrate doses would provide an added benefit to supervised aerobic exercise in HTN and HFpEF patients.

Response to Endurance Exercise Training in Older Adults with Heart Failure with Preserved or Reduced Ejection Fraction.

OBJECTIVES: To systematically examine the relative magnitude and predictors of responses to exercise training in older adult with heart failure (HF) with reduced ejection fraction (HFrEF), and preserved EF (HFpEF). DESIGN: Secondary analysis of a randomized controlled trial. SETTING: Outpatient cardiac rehabilitation program. PARTICIPANTS: Individuals with HF (24 HFrEF, 24 HFpEF) who underwent supervised exercise training. MEASUREMENTS: The study included individual-level data from the exercise training arms of a randomized controlled trial that evaluated the effect of 16 weeks of supervised moderate-intensity endurance exercise training in older adults with chronic, stable HFpEF and HFrEF. Changes in peak oxygen uptake (VO2peak ) in response to supervised training in individuals with HFpEF were compared with that of individuals with HFrEF. The significant clinical predictors of changes in VO2peak with exercise training were assessed using univariate and multivariate regression models. RESULTS: Training-related improvement in VO2peak was higher in participants with HFpEF than in those with HFrEF (change: 18.7 ± 17.6% vs -0.3 ± 15.4%, P < .001). In univariate analysis, echocardiographic abnormalities in left ventricular structure and function and lower body mass index were associated with blunted response of VO2peak with exercise training. In multivariate regression analysis using stepwise selection, submaximal exercise systolic blood pressure, and resting early deceleration time were independent predictors of change in VO2peak . CONCLUSION: The change in VO2peak in response to endurance exercise training in older adults with HF differs significantly according to HF subtype, with greater VO2peak improvement in HFpEF than HFrEF. These results suggest that the current Centers for Medicare and Medicaid Services policy excluding individuals with HFpEF from reimbursement from cardiac rehabilitation may need to be revisited.