Search

Background: Aiming to establish an effective tool in new cardiac rehabilitation programs, we investigated the use of a lumbar-type hybrid assistive limb (HAL) in patients with heart failure (HF) who had difficulty in walking at the usual speed of healthy subjects (≈80 m/min)., Methods and results: We randomly assigned 28 HF patients (age, 73.1±13.8 years) to perform a sit-to-stand exercise with or without HAL. The sit-to-stand exercise was repeated as many times as possible as cardiac rehabilitation therapy over a period of 6-10 days. We measured 5 parameters before and after the completion of cardiac rehabilitation: B-type natriuretic peptide, Short Physical Performance Battery (SPPB), 6-min walking distance (6MWD), 30-s chair-stand test (CS-30), and isometric knee extensor muscle strength. The SPPB and 6MWD were significantly improved, and the CS-30 score was somewhat improved, after the exercise therapy in both the HAL and non-HAL groups. The knee extensor muscle strength improved significantly in the HAL group (0.29±0.11 to 0.35±0.11 kgf/kg, P<0.01), but showed no change in the non-HAL group (0.35±0.11 to 0.35±0.13 kgf/kg, P=0.40)., Conclusions: The improved knee extensor muscle strength in the HAL group suggests that the lumbar-type HAL may be an effective tool for cardiac rehabilitation in HF patients with frailty, which is a predictor of poor prognosis in HF.

Background: Left ventricular ejection fraction (LVEF) can dramatically change when the patient has acute decompensated heart failure (ADHF). We investigated the impact of LVEF and subsequent changes on prognosis in patients with ADHF through a prospective study.Methods and Results: A total of 516 hospitalized patients with ADHF were evaluated. Echocardiography was performed on admission, prior to discharge, and 1 year after discharge. The primary endpoint was a composite of cardiovascular death and hospitalization. In heart failure with reduced EF (HFrEF; LVEF <40%), LVEF did not significantly improve during hospitalization (P=0.348); however, it improved after discharge (P<0.001). In contrast, LVEF improved during hospitalization (P<0.001) in HF with preserved EF (HFpEF; LVEF ≥50%). In HF with mid-range EF (HFmrEF; LVEF 40-49%), LVEF consistently improved throughout the observation period (P<0.001). A multivariable Cox model showed that improved LVEF after discharge was associated with a better outcome in HFrEF (hazard ratio [HR]: 0.951; 95% confidence interval [CI]: 0.928-0.974; P<0.001), while improved LVEF during hospitalization was associated with a better outcome in HFpEF (HR: 0.969; 95% CI: 0.940-0.998; P=0.038)., Conclusions: Improved LVEF after discharge in HFrEF and during hospitalization in HFpEF was associated with a better prognosis in patients with ADHF. Longitudinal improvements in LVEF had different prognostic impact, depending on the HF type by LVEF measurement.

Background: Although experimental animal studies report many pleiotropic effects of dipeptidyl peptidase-4 inhibitors (DPP-4i), their prognostic value has not been demonstrated in clinical trials.Methods and Results:Among 838 prospectively enrolled heart failure (HF) patients hospitalized for acute decompensated HF, 79 treated with DPP-4i were compared with 79 propensity score-matched non-DPP-4i diabetes mellitus (DM) patients. The primary endpoint was all-cause mortality; the secondary endpoint was a composite of cardiovascular death and hospitalization. During follow-up (423±260 days), 8 patients (10.1%) in the DPP-4i group and 13 (16.5%) in the non-DPP-4i group died (log-rank, P=0.283). The DPP-4i group did not have a significantly higher rate of all-cause mortality (log-rank, P=0.283), or cardiovascular death or hospitalization (log-rank, P=0.425). In a subgroup analysis of HF with preserved ejection fraction (HFpEF; n=75), the DPP-4i group had a significantly better prognosis than the non-DPP-4i group regarding the primary endpoint (log-rank, P=0.021) and a tendency to have better prognosis regarding the secondary endpoint (log-rank, P=0.119). In patients with HF with reduced EF (n=83), DPP-4i did not result in better prognosis., Conclusions: DPP-4i did not increase the risk of adverse clinical outcomes in patients with DM and HF. DPP-4i may be beneficial in HFpEF.

Background: It remains unclear whether patients with chronic heart failure (CHF) and advanced left ventricular (LV) dysfunction on β-blocker therapy benefit from exercise training (ET)., Methods and Results: We studied 45 CHF patients with advanced LV dysfunction [ejection fraction (LVEF) < 25%] and impaired exercise tolerance [normalized peak oxygen uptake (PVO₂) < 70%] receiving a β-blocker: 33 patients participated in a cardiac rehabilitation program with ET (ET group) and 12 did not (inactive control group). Exercise capacity, LV dimension and plasma B-type natriuretic peptide (BNP) were assessed before and after a 3-month study period. At baseline, both groups had markedly reduced LVEF (ET group 18 ± 4% vs. Control group 18 ± 5%, NS) and impaired exercise capacity (normalized PVO₂ 51 ± 10% vs. 55 ± 9%, NS). Although one patient in the ET group withdrew from the program due to worsening CHF, no serious cardiac events occurred during the ET sessions. After 3 months, the ET group (n = 24) had significantly improved PVO₂ by 16 ± 15% (1,005 ± 295 to 1,167 ± 397ml/min, P < 0.001), while the PVO₂ of the control group was unchanged. LV end-diastolic dimension decreased in both groups to a similar extent, but plasma BNP was significantly decreased only in the ET group (432 to 214 pg/ml, P < 0.05)., Conclusions: The data indicate that in CHF patients with advanced LV dysfunction on β-blocker therapy, ET successfully improves exercise capacity and BNP without adversely affecting LV remodeling or causing serious cardiac complications.

Background: Exercise training (ET) is an emerging therapy for chronic heart failure, but the baseline patient characteristics for predicting cardiac events (CEs) during the course of ET remain unknown., Methods and Results: Of the 111 stable heart failure patients who participated in a 3-month ET program, 6 withdrew from the program for cardiac reasons and 9 had transient interruptions in the program because of CEs. The baseline clinical characteristics of these 15 patients (CE group) and the remaining 96 patients (No-CE group) were compared. Compared with the No-CE group, the CE group had a significantly higher prevalence of pacemaker/implantable cardioverter-defibrillators, larger left ventricular end-diastolic diameter (LVEDDs), lower peak oxygen uptake, greater ventilation drive, and higher plasma brain natriuretic peptide concentration at baseline. Multivariate logistic regression analysis showed that a larger LVEDD was a significant predictor of the occurrence of a transient interruption to or permanent withdrawal from the ET program because of CEs. Receiver operating characteristic curve analysis demonstrated that an LVEDD > or = 65 mm had a sensitivity of 93% and specificity of 48% in predicting CEs., Conclusions: Patients with a large LVEDD (> or = 65 mm) at baseline should be monitored carefully during the course of an ET program.

Background: The relationship of the genotype for the angiotensin-converting enzyme (ACE) with exercise capacity or training effects has been studied in athletes or healthy persons, but recently the ACE DD genotype was reported to be associated with decreased exercise capacity in patients with congestive heart failure. Therefore, in the present study the association between the ACE genotype and exercise capacity was investigated in patients with acute myocardial infarction (AMI) participating in cardiac rehabilitation (CR) for 3 months., Methods and Results: The study population comprised 168 patients stratified as II (n=75), ID (n=67), and DD (n=26) according to ACE genotype. Baseline left ventricular ejection fraction (LVEF) was similar among the genotype groups. In all patients, exercise capacity (peak work rate (PWR) and peak oxygen uptake (PVO 2)) significantly increased after CR. However, no differences were observed in PWR and PVO2 among the genotype groups at baseline or after CR. The results were similar even when analyzed in 60 patients with left ventricular (LV) dysfunction (LVEF <45%)., Conclusion: The present study suggests that there is no association between ACE I/D polymorphism and exercise capacity in patients after AMI, even with LV dysfunction. Furthermore, ACE genotype may have no influence on the effects of CR after AMI.

Peripartum cardiomyopathy is a rare cardiac disorder characterized by the development of heart failure in the last month of pregnancy or up to 5 months postpartum in women without other determinable causes of cardiac failure. Intracardiac thrombi have been found at autopsy in some patients with this condition and have been demonstrated in the left or right ventricles on 2-dimensional echocardiography. A 23-year-old woman presented with peripartum cardiomyopathy and biventricular thrombi on echocardiography. The thrombi were spherical, pedunculate, shaggy and irregular in configuration, and freely mobile, suggesting that they were fresh. She was treated with conventional heart failure therapy and anticoagulants. Four days later, the apical thrombi within both ventricles had disappeared and there was no evidence of embolism on physical examination. The hypercoagulable state of the peripartum period and the severe biventricular dysfunction most likely led to the formation of biventricular thrombi.

Trials have demonstrated that carvedilol can produce hemodynamic, symptomatic, and prognostic improvements in dilated cardiomyopathy (DCM), but some DCM patients have deteriorated after carvedilol, developing congestive heart failure. The present study investigated the use of isoproterenol (ISP) stress echocardiography to select those patients with DCM who would respond to carvedilol. ISP was infused intravenously in 22 patients with DCM and they were classified into 2 groups based on the left ventricular systolic response: good response to ISP [change in fractional shortening (FS) with ISP > 0.05, n=13] and poor response to ISP (change < or = 0.05, n=9). In the good response group, FS significantly increased from 0.12+/-0.04 to 0.17+/-0.08 (mean+/-SD, p<0.05) with carvedilol, and 7 patients improved symptomatically (New York Heart Association class). However, in the poor response group, no significant difference was observed between FS at baseline and that at the end of follow-up. Moreover, only 1 patient in the poor response group improved symptomatically. ISP stress echocardiography can assist in selecting patients with DCM who will respond positively to carvedilol.

Exercise hypotension has been documented in patients with hypertrophic cardiomyopathy (HCM). Some investigators reported that this is due to an inadequate increase of systemic vascular resistance during or after exercise. The aim of this study was to investigate the pathogenesis of limb vascular response abnormalities in patients with idiopathic HCM. Thirteen patients with HCM and 9 healthy controls were administered an endothelium-dependent dilator (acetylcholine), a direct smooth muscle dilator (nitroglycerin), an alpha-adrenergic stimulator (phenylephrine), and a beta-adrenergic stimulator (isoproterenol) by intra-arterial infusion. Peripheral vascular resistance was assessed by forearm plethysmography at rest and during each infusion to obtain the percentage change in vascular resistance. Isoproterenol, acetylcholine and nitroglycerin produced dose-related vasodilatation with no significant differences between HCM patients and healthy controls. The percentage increase in vascular resistance was significantly less in HCM patients than in healthy controls after phenylephrine infusions of 0.5 microg/min (155+/-38% vs 195+/-47%, mean+/-SD, p<0.05) and 1.0 microg/min (174+/-49% vs 238+/-65%, p<0.05). Vasoconstriction mediated by alpha-adrenergic receptors appeared to be impaired in the peripheral vasculature of patients with HCM.