Timothy R. McConnell

Exercise training for heart failure patients improves respiratory muscle endurance, exercise tolerance, breathlessness, and quality of life.

PURPOSEnIncreased respiratory muscle endurance and peak oxygen consumption (VO(2peak)) induced by respiratory muscle training support the relationship between respiratory muscle function and exercise capacity in patients with heart failure. This raises the question whether exercise-training results in increased respiratory muscle function contributing to an increased exercise tolerance, a decreased perception of breathlessness, and an improved quality of life.nnnMETHODSnProspective cohort analysis was completed on 24 patients with New York Heart Association (NYHA) Class III heart failure [18 men, 6 women; aged = 64 (SD 7.9) years; percent ejection fraction (%EF) = 24.0 (SD 7.8)]. Maximal sustainable ventilatory capacity (MSVC), submaximal and peak exercise responses, perception of breathlessness, and quality of life were measured before (baseline) and after (end of study) 12 weeks of exercise training.nnnRESULTSnAs a result of exercise training, VO(2peak) (P=.01) and MSVC (P<.001) increased, with MSVC contributing to a larger proportion of the variability for VO(2peak) at study completion (r=0.57 vs 0.42). Although stroke volume did not increase beyond exercise at 25 W and did not change with exercise training, ventilation decreased during exercise (P<.05), perception of breathing difficulty (P<.05) was reduced, and quality of life was enhanced (P=.008).nnnCONCLUSIONSnDespite no increase in cardiac output and stroke volume, respiratory muscle endurance improved with exercise training, contributing to increased exercise capacity, decreased breathlessness, and decreased perception of breathlessness. Practical implications can include less frequent rest periods and fatigue, greater confidence, maintenance of independence, and enhanced quality of life.

Quality of life and self-efficacy: gender and diagnoses considerations for management during cardiac rehabilitation.

PURPOSEnOutcome measurement research has extended beyond traditional clinical and physiologic parameters to include psychosocial aspects. Accordingly, the purpose of this study was to investigate quality-of-life (QOL) and self-efficacy disparities for gender and diagnoses during participation in cardiac rehabilitation.nnnMETHODSnFor this study, 472 patients (114 women and 358 men) were stratified by gender and then again by diagnosis to include surgical revascularization, myocardial infarction, and percutaneous coronary intervention. Measures obtained at baseline and at the end of the study assessed quality of life (QOL-o = total score), including emotional (QOL-e) and limitation (QOL-l) domains; self-efficacy (SE-o = total score), including ambulatory (SE-a) and muscular (SE-m) domains; and caloric expenditure.nnnRESULTSnBoth self-efficacy and QOL were greater at the end of the study across genders (P <.05). The men had greater self-efficacy values for all domains (P <.05). There was a significant gender-time interaction for QOL-e (P <.05) among the women, and for QOL-o, QOL-l, and all self-efficacy domains (P <.05) among the surgical revascularization patients. Percutaneous coronary intervention patients had higher self-efficacy scores throughout. Caloric expenditure was a consistent positive predictor of self-efficacy and QOL-e (P <.05).nnnCONCLUSIONSnQuality of life and self-efficacy improve during cardiac rehabilitation across gender and diagnoses. Female and revascularized patients present with low QOL and self-efficacy scores initially, but improvements in scores similar to or greater than the men can be expected. Because the self-efficacy scores of percutaneous coronary intervention patients are higher and their physical limitations are less prohibitive, these patients can be progressed more aggressively. Improvements in self-efficacy scores parallel caloric expenditure increases.

Variables Measured During Cardiopulmonary Exercise Testing as Predictors of Mortality in Chronic Systolic Heart Failure.

BACKGROUNDnData from a cardiopulmonary exercise (CPX) test are used to determine prognosis in patients with chronic heart failure (HF). However, few published studies have simultaneously compared the relative prognostic strength of multiple CPX variables.nnnOBJECTIVESnThe study sought to describe the strength of the association among variables measured during a CPX test and all-cause mortality in patients with HF with reduced ejection fraction (HFrEF), including the influence of sex and patient effort, as measured by respiratory exchange ratio (RER).nnnMETHODSnAmong patients (nxa0= 2,100, 29% women) enrolled in the HF-ACTION (HF-A Controlled Trial Investigating Outcomes of exercise traiNing) trial, 10 CPX test variables measured at baseline (e.g., peak oxygen uptake [Vo2], exercise duration, percent predicted peak Vo2 [%ppVo2], ventilatory efficiency) were examined.nnnRESULTSnOver a median follow-up of 32 months, there were 357 deaths. All CPX variables, except RER, were related to all-cause mortality (all pxa0< 0.0001). Both %ppVo2 and exercise duration were equally able to predict (Wald chi-square: ∼141) and discriminate (c-index: 0.69) mortality. Peak Vo2 (ml·kg(-1)·min(-1)) was the strongest predictor of mortality among men (Wald chi-square: 129) and exercise duration among women (Wald chi-square: 41). Multivariable analyses showed that %ppVo2, exercise duration, and peak Vo2 (ml·kg(-1)·min(-1)) were similarly able to predict and discriminate mortality. In men, a 10% 1-year mortality rate corresponded to a peak Vo2 of 10.9 ml·kg(-1)·min(-1) versus 5.3xa0ml·kg(-1)·min(-1) in women.nnnCONCLUSIONSnPeak Vo2, exercise duration, and % ppVo2 carried the strongest ability to predict and discriminate the likelihood of death in patients with HFrEF. The prognosis associated with a given peak Vo2 differed by sex. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437).

Relationships Between Changes in Patient-Reported Health Status and Functional Capacity in Outpatients With Heart Failure

BACKGROUNDnHeart failure trials use a variety of measures of functional capacity and quality of life. Lack of formal assessments of the relationships between changes in multiple aspects of patient-reported health status and measures of functional capacity over time limits the ability to compare results across studies.nnnMETHODSnUsing data from HF-ACTION (N = 2331), we used the Pearson correlation coefficients and predicted change scores from linear mixed-effects modeling to demonstrate the associations between changes in patient-reported health status measured with the EQ-5D visual analog scale and the Kansas City Cardiomyopathy Questionnaire (KCCQ) and changes in peak VO(2) and 6-minute walk distance at 3 and 12 months. We examined a 5-point change in KCCQ within individuals to provide a framework for interpreting changes in these measures.nnnRESULTSnAfter adjustment for baseline characteristics, correlations between changes in the visual analog scale and changes in peak VO(2) and 6-minute walk distance ranged from 0.13 to 0.28, and correlations between changes in the KCCQ overall and subscale scores and changes in peak VO(2) and 6-minute walk distance ranged from 0.18 to 0.34. A 5-point change in KCCQ was associated with a 2.50-mL kg(-1) min(-1) change in peak VO(2) (95% CI 2.21-2.86) and a 112-m change in 6-minute walk distance (95% CI 96-134).nnnCONCLUSIONSnChanges in patient-reported health status are not highly correlated with changes in functional capacity. Our findings generally support the current practice of considering a 5-point change in the KCCQ within individuals to be clinically meaningful.

Reducing cardiovascular disease risk in medically underserved urban and rural communities

OBJECTIVESnThe aim of this study is to evaluate methods for lowering cardiovascular disease (CVD) risk in asymptomatic urban and rural underserved subjects.nnnBACKGROUNDnMedically underserved populations are at increased CVD risk, and systems to lower CVD risk are needed. Nurse management (NM) and telemedicine (T) systems may provide low-cost solutions for this care.nnnMETHODSnWe randomized 465 subjects without overt CVD, with Framingham CVD risk >10% to NM with 4 visits over 1 year, or NM plus T to facilitate weight, blood pressure (BP), and physical activity reporting. The study goal was to reduce CVD risk by 5%.nnnRESULTSnThree hundred eighty-eight subjects completed the study. Cardiovascular disease risk fell by ≥ 5% in 32% of the NM group and 26% of the T group (P, nonsignificant). In hyperlipidemic subjects, total cholesterol decreased (NM -21.9 ± 39.4, T -22.7 ± 41.3 mg/dL) significantly. In subjects with grade II hypertension (systolic BP ≥ 160 mm Hg, 24% of subjects), both NM and T groups had a similar BP response (average study BP: NM 147.4 ± 17.5, T 145.3. ± 18.4, P is nonsignificant), and for those with grade I hypertension (37% of subjects), T had a lower average study BP compared to NM (NM 140.4 ± 16.9, T 134.6 ± 15.0, P = .058). In subjects at high risk (Framingham score ≥ 20%), risk fell 6.0% ± 9.9%; in subjects at intermediate risk (Framingham score ≥ 10, < 20), risk fell 1.3% ± 4.5% (P < .001 compared to high-risk subjects). Medication adherence was similar in both high- and intermediate-risk subjects.nnnCONCLUSIONSnIn 2 underserved populations, CVD risk was reduced by a nurse intervention; T did not add to the risk improvement. Reductions in BP and blood lipids occurred in both high- and intermediate-risk subjects with greatest reductions noted in the high-risk subjects. Frequent communication using a nurse intervention contributes to improved CVD risk in asymptomatic, underserved subjects with increased CVD risk. Telemedicine did not change the effectiveness of the nurse intervention.

Religiosity and Spirituality: Influence on Quality of Life and Perceived Patient Self-Efficacy among Cardiac Patients and Their Spouses

The purpose of this study was to determine the influence of spirituality, religiosity, and religious coping on quality of life and self-efficacy among couples following a first time cardiac event. There was no significant association between measures for spirituality and religiosity and couples’ ratings for quality of life and self-efficacy. Negative forms of religious coping were associated with lower levels of quality of life and decreased confidence in the patient’s ability to perform physical tasks. Spouses’ measures for quality of life, self-efficacy, spirituality, religiosity, and religious coping were associated with patients’ measures for the same study variables.

Cardiac Rehabilitation Without Exercise Tests for Post-Myocardial Infarction and Post-Bypass Surgery Patients

PURPOSEnTo compare the progress of patients who were exercise tested before or during cardiac rehabilitation versus those patients who were not tested.nnnMETHODSnEighty-eight (88) post-myocardial infarction patients and 141 post-bypass surgery patients had a symptom-limited exercise test before or during 12 weeks of cardiac rehabilitation. Another 125 post-myocardial infarction and 146 post-surgery patients were not tested.nnnRESULTSnCaloric expenditure during class increased for the entire group (P < 0.001) from week 1 to week 12. Body weight decreased for the entire group as a result of cardiac rehabilitation (P < 0.001). Tricep skinfolds decreased for the entire group (P < 0.001) while subscapular skinfolds did not change (P = 0.28). The percent change from week 1 to week 12 for both groups was similar for all variables. No problems occurred during cardiac rehabilitation that required emergency medical management.nnnCONCLUSIONSnPatients completing a 12-week cardiac rehabilitation program can be safely progressed in terms of their exercise capacity without an entry exercise test. This is desirable in a managed-care setting for reducing costs while maintaining effective patient care. Such factors as staff training and experience, institutional philosophy, patient referral patterns, and facility location must be considered before adopting a no-test policy.

Religiosity and Religious Coping in Patients with Cardiovascular Disease: Change over Time and Associations with Illness Adjustment

Little is known about the longitudinal relationship between religiosity/spirituality (R/S) and patient physical and mental health in patients with cardiovascular disease. Forty-three patients with a first-time myocardial infarction or coronary artery revascularization bypass surgery completed measures of religiosity, religious coping, quality of life (QOL), and weight prior to a cardiac rehabilitation program and 1 and 2xa0years later. R/S changed over time; the direction of the change varied by type of R/S. Increases in religiosity were associated with increases in weight and QOL; increases in religious coping were associated with decreases in weight and increases in QOL.

Pulmonary manifestations of chronic heart failure.

These findings underscore the importance of understanding the complex interactions of multiple-organ systems in a chronic systemic disease state like congestive heart failure. The exaggerated ventilatory response in patients with heart failure is clearly multifactorial and it remains difficult to decipher whether this response results from or contributes to the sensation of dyspnea. Pulmonary dysfunction including ventilation-perfusion mismatching, decreased lung compliance, restriction, airway obstruction, decreased diffusion capacity, and decreases in respiratory muscle strength and endurance contribute to an inefficient breathing pattern and increased work of breathing. This is further compounded by the limited ability of the failing heart to meet the metabolic demands of the respiratory muscles, leading to under-perfusion and ischemia. This imbalance contributes to perceived dyspnea and exercise limitations. Understanding these physiologic cardiopulmonary interactions may lead to therapeutic modalities, such as respiratory muscle training, aimed at disrupting this intertwined cycle of events and improving functional capacity in patients with heart failure.

Body fat distribution's impact on physiologic outcomes during cardiac rehabilitation.

BACKGROUNDnHigh waist-to-hip ratios (WHRs) predispose individuals to metabolic syndromes that may affect outcome responses to cardiac rehabilitation programs.nnnMETHODSnA total of 101 male patients who had undergone coronary artery revascularization surgery and completed 12 weeks of cardiac rehabilitation were divided into lower (LOWHR, n = 51) and higher (HIWHR, n = 50) waist-to-hip groups. Outcomes were measured at week 1 and week 12 of cardiac rehabilitation.nnnRESULTSnWaist-to-hip ratio and body weight were greatest for HIWHR (P < 0.001) with no between-group differences in the amount of change from week 1 to 12. Triceps and subscapular skin-folds were greater for HIWHR (P < 0.001) with no difference in the amount of change between groups. Caloric expenditure during exercise class was higher for LOWHR (P = 0.022). Daily caloric expenditure was greater for LOWHR (P = 0.034) as was daily caloric intake (P < 0.001). There were no group differences for VO2peak and ventilatory anaerobic threshold (VAT) with nonsignificant trends for greater increases in LOWHR.nnnCONCLUSIONSnCardiac rehabilitation patients with greater WHRs expend less calories during exercise classes. To enhance overall caloric expenditure and obtain positive outcomes, cardiac rehabilitation professionals must emphasize greater activity with less sedentary time throughout the patients normal daily routine. The validity of using self-reported caloric intake and expenditure values in the cardiac rehabilitation population is questionable.