The Value of Detecting Asymptomatic Signs of Myocardial Ischemia in Patients With Coronary Artery Disease in Outpatient Cardiac Rehabilitation.

BACKGROUND: Electrocardiographic (ECG) monitored outpatient cardiac rehabilitation (OP-CR) is routinely performed following a variety of cardiovascular procedures and conditions. OBJECTIVE: The aim of this study is to determine if diagnostic-quality ECG monitoring in patients with coronary artery disease (CAD) during OP-CR is useful in identifying asymptomatic myocardial ischemia, resulting in change(s) in care or medical management. METHODS: A retrospective analysis of ECG monitoring was done on all OP-CR patients diagnosed with CAD (n = 1213) from January 2000 through June 2013. RESULTS: Nearly a quarter of the patients (24%; n = 288) displayed at least 1 mm of asymptomatic ST-segment depression at 80 milliseconds after the J-point during at least 1 session of OP-CR. Of these patients, 57% had medical management change(s) compared with 24% for those who did not show ECG changes suggesting ischemia (P < .0001). In patients with asymptomatic ischemia having medical management change(s), 84% resulted directly from OP-CR staff detection. Fewer patients diagnosed with myocardial infarction and coronary artery bypass graft surgery demonstrated ECG signs of ischemia, whereas more patients diagnosed with stable angina and percutaneous coronary interventions demonstrated ECG signs of ischemia. CONCLUSION: This study demonstrates that most patients with CAD showing asymptomatic ECG signs suggesting ischemia undergo medical management change(s) as a result of the finding. Diagnostic-quality ECG monitoring during OP-CR appears warranted in this population.

Text-messaging program improves outcomes in outpatient cardiovascular rehabilitation.

BACKGROUND: Outpatient cardiac rehabilitation (OP-CR) is a highly beneficial program but vastly under utilized. METHODS: The efficacy of a text-messaging program was analyzed to determine if implementation could improve number of OP-CR sessions completed. All patients enrolled in OP-CR from July 2011 through December 2012 were invited to join a text-messaging program on their first visit. The program required that the patient possesses a cell phone with texting capabilities. Participants received three to five text-messages per week offering heart-healthy tips and requests for body weight, minutes of exercise, blood pressure, and medication adherence. Patients enrolled (n = 52) in the texting program (Tx) were compared with those who were not (n = 185) (NTx) in several clinical indices and were compared using matched pairs (same subjects), comparison of means and frequencies, chi-square statistics, t-tests, and the Wilcoxon Rank Sum test. RESULTS: Significantly more patients in the Tx group completed the OP-CR program (61.5% versus 50%, p = 0.01). For those completing OP-CR, subjects in the Tx group completed significantly more sessions (31.4) than the NTx group (25.3) (p = 0.01). Additionally, significantly more in the Tx group were younger than those in the Ntx group. CONCLUSIONS: Patients enrolled in OP-CR who participated in a text-messaging program were younger, attended significantly more sessions and were significantly more likely to complete the program.

Martial art training enhances the glutathione antioxidant system in middle-aged adults.

The purpose of this study was to compare the antioxidant capacity of physically active middle-aged martial artists to age-matched sedentary controls. Nine sedentary subjects (mean age 52.9 yr) and 9 martial artists (mean age 51.8 yr) who practice Soo Bahk Do, a Korean martial art and were age- and sex-matched performed a graded exercise test (GXT) using a modified Bruce protocol. Ages ranged from 41 to 58 years. A GXT has been shown to be an effective technique for inducing oxidative stress. Glutathione (GSH) is the body's most highly concentrated antioxidant, is the central component of the antioxidant system, and plays an essential role in protecting tissues against oxidative stress. Free radical oxidation leads to the transformation of GSH to glutathione disulfide (GSSG). Venous blood samples for GSH and GSSG were collected before and immediately after the GXT. Repeated measures analysis of variance were performed on the resting baseline values and immediate post-GXT values of GSH, GSSG, and GSH:GSSG to compare groups. The blood GSH, GSSG, and GSH:GSSG levels were significantly different (p < 0.001) between the 2 groups at rest and after the GXT. The Soo Bahk Do practitioners had higher resting levels of GSH and lower levels of GSSG and responded more effectively to acute oxidative stress than the age-matched sedentary controls. Soo Bahk Do appears to enhance the antioxidant defense system and may be an effective intervention for improving overall health by protecting against the adverse effects of oxidative stress that is associated with the free radical theory of aging. Health professionals should be aware of alternative methods of training, conditioning, and exercise that can improve the general adaptation response to oxidative stress.

Relationship of resting B-type natriuretic peptide level to cardiac work and total physical work capacity in heart failure patients.

PURPOSE: Plasma B-type natriuretic peptide (BNP) levels obtained at rest have been previously shown to be correlated with the global functional capacity measures of peak oxygen uptake (V(O(2peak))) and the minute ventilation/carbon dioxide (VE/V(O(2))) slope. The purpose of this study was to assess the relationship of the plasma BNP level to the rate-pressure product (RPP) as an indicator of central or cardiac work capacity. METHODS: Twenty-two subjects (12 men), mean age 57 +/- 12 years, diagnosed with heart failure (8 ischemic/14 nonischemic) were recruited. All subjects were stable on optimal medical therapy for at least 1 month. Blood samples for BNP level analysis were obtained at rest. Subjects underwent a symptom-limited treadmill exercise test using a ramping protocol while V(O(2)), heart rate (HR), and blood pressure (BP) were monitored. Correlation analyses were conducted to assess the relationship of BNP level to RPP level, V(O(2peak), VE/V(O(2)) slope, end-tidal CO(2) pressure (P(ET)CO(2)), and left ventricular ejection fraction (LVEF). RESULTS: Resting BNP levels were significantly correlated with RPP levels (r = -0.69). The BNP level and the RPP level were correlated with V(O(2peak)) (r = -0.63 and r = 0.66, respectively) and VE/V(O(2)) slope (r = 0.53 and r = -0.54, respectively). The RPP level but not the BNP level was correlated with P(ET)CO(2) (r = 0.57). Neither BNP nor RPP levels were well correlated with LVEF (r = -0.26 and r = 0.14, respectively). DISCUSSION: The results of this study suggest that resting plasma BNP level may be a useful clinical measure for evaluating both global functional capacity and myocardial specific work capacity in individuals with heart failure.

Effects of exercise training on the glutathione antioxidant system.

PURPOSE: The glutathione (GSH) antioxidant system has been shown to play an important role in the maintenance of good health and disease prevention. Various approaches have been used to enhance GSH availability including diet, nutritional supplementation, and drug administration, with minor to moderate success. Exercise training has evolved as a new approach. The purpose of this study was to investigate the effects of aerobic exercise training (AET), circuit weight training (CWT), and combined training (AET+CWT) on general adaptations, and resistance to acutely induced oxidative stress, as assessed by changes in the GSH antioxidant system. METHODS: Eighty healthy sedentary volunteers participated in the study who were randomly assigned to four groups: control (no exercise); AET, CWT, and AET+CWT. Exercise training programs were designed to simulate outpatient cardiac rehabilitation (40 min x 3 days x 6 weeks). Venous blood sampling was taken at rest and post maximal graded exercise test (GXT). A new improved spectrophotometric venous assay analysis technique was used. A mixed model repeated measures analysis of variance design was used with t-tests for preplanned comparisons evaluated at Bonferroni-adjusted alpha levels. RESULTS: Effectiveness of the exercise training programs was demonstrated by significant between-group (exercise group versus control) comparisons. AET, CWT, and AET+CWT showed significant pretraining-posttraining increases in resting GSH and glutathione-glutathione disulfide ratio (GSH:GSSG), and significant decreases in GSSG levels (P<0.005). AET+CWT showed the most pronounced effect compared with AET or CWT alone (P<0.025). CONCLUSION: This study represents the first longitudinal investigation involving the effects of multiple modes of exercise training on the GSH antioxidant system with evidence, suggesting the GHS:GSSG ratio as the most sensitive change marker. The significant findings of this study have potential clinical implications to individuals involved in cardiac and pulmonary rehabilitation.

Effects of a maximal graded exercise test on glutathione as a marker of acute oxidative stress.

PURPOSE: Strenuous exercise in animal studies has been shown to cause acute oxidative stress due to the generation of oxygen-centered free radicals reflected in lower levels of glutathione (GSH), higher levels of glutathione disulfide (GSSG), and a drop in GSH:GSSG ratios, the maintenance of which is crucial for a variety of cell functions. Human studies on this topic are limited. The purpose of this study was to investigate the effects of a maximal graded exercise test GXTmax (modified Bruce protocol) on GSH as a marker of acute oxidative stress, and whether full recovery will occur at 60 minutes postexercise. METHODS: Eighty sedentary subjects were used as a sample of convenience. Venous blood samples for GSH and GSSG were collected directly before, immediately after, and 60 minutes post-GXTmax. Repeated-measures analysis of variance and Bonferroni adjusted t tests (post-GXTmax) versus resting, and 60 minutes recovery versus resting) were used for data analysis. RESULTS: As an acute response to maximal exercise, the GSH levels dropped significantly from a resting baseline value of 1025.75 microM to an immediate post-GXTmax value of 893.30 microM (pooled SE = 7.17 microM). The GSSG levels significantly increased from 2.24 microM to 3.15 microM (pooled SE = 0.03 microM). The GSH:GSSG ratio levels significantly dropped from baseline 462.12 to 276.40 postexercise (pooled SE = 5.98). The blood GSH, GSSG, and GSH:GSSG ratio levels showed no significant difference at 60 minutes post-GXTmax when compared with resting values, indicating full recovery. CONCLUSION: The current results indicated that in sedentary individuals, a maximal treadmill GXT is an effective technique for inducing acute oxidative stress as evidenced by GSH system responses, with full return to resting baseline levels within 60 minutes of recovery. The potential for using this model in assessing oxidative stress responses to cardiac and pulmonary rehabilitation is of clinical interest, with a need for further investigation.