Changes in exercise capacity, ventilation, and body weight following heart transplantation

AIMS: Peak oxygen uptake adjusted to body weight (peak VO(2)) and ventilatory efficiency (VE/VCO(2)-slope) are important prognostic parameters in chronic heart failure. Our study prospectively examined changes in these parameters over 24 months following heart transplantation (HTx) and evaluated the potentially confounding effects of weight gain. METHODS AND RESULTS: One hundred patients with chronic heart failure (16 female, mean age at HTx 53.9+/-9.6 years) underwent cardiopulmonary exercise testing before and 3, 6, 12 and/or 24 months after HTx. Twenty-five healthy individuals served as matched normals. VE/VCO(2)-slope during exercise improved significantly at 6 (-23.7%), 12 (-21.3%), and 24 months (-32.3%; all p<0.002 vs. baseline). At 6 months, VE/VCO(2)-slopes were similar to the matched normals (31.8+/-4.3), 46 of 78 patients achieved values within the 95% confidence interval of normal. Peak VO(2) increased significantly after HTx at 6 (+31.8%), 12 (+36.2%), and 24 months (+42.2%; all p<0.005). None of the patients reached values within the 95% CI of normal. Although VE/VCO(2)-slope and peak VO(2) were correlated inversely at every time point (p<0.03), reduction in VE/VCO(2)-slope did not correlate with increase in peak VO(2). Symptoms that limited exercise changed from dyspnoea before HTx to leg fatigue after HTx. CONCLUSION: Following HTX, VE/VCO(2)-slope returns to normal values in the majority of patients; however, despite improvement, peak VO(2) remains abnormal in all patients. Symptoms causing patients to stop exercising change from dyspnoea to leg fatigue.     

Ventilatory efficiency slope correlates with functional capacity,outcomes, and disease severity in pediatric patients with pulmonary hypertension

Background

Cardiopulmonary exercise testing is widely used in a variety of cardiovascular conditions. Ventilatory efficiency slope can be derived from submaximal exercise testing. The present study sought to evaluate the relationship between ventilatory efficiency slope and functional capacity, outcomes, and disease severity in pediatric patients with pulmonary hypertension.

Methods

Seventy six children and young adults with a diagnosis of pulmonary hypertension (PH) performed 258 cardiopulmonary exercise tests from 2001 to 2011. Each individual PH test was matched to a control test. Ventilatory efficiency slope was compared to traditional measures of functional capacity and disease severity including WHO functional classification, peak oxygen consumption, and invasive measures of pulmonary arterial pressures and pulmonary vascular resistance.

Results

Ventilatory efficiency slope was significantly higher in patients with pulmonary arterial hypertension, with an estimated increase of 7.2 for each increase in WHO class (p < 0.0001), compared with normal control subjects (38.9 vs. 30.9, p < 0.001). Ventilatory efficiency slope correlated strongly with invasive measures of disease severity including pulmonary vascular resistance index (r = 0.61), pulmonary artery pressure (r = 0.58), mean pulmonary artery pressure/mean aortic pressure ratio (r = 0.52), and peak VO₂ (r = − 0.58). Ventilatory efficiency slope in 12 patients with poor outcomes (9 death, 3 lung transplant), was significantly elevated compared to patients who did not (51.1 vs. 37.9, p < 0.001).

Conclusions

Ventilatory efficiency slope correlates well with invasive and noninvasive markers of disease severity including peak VO₂, WHO functional class, and catheterization variables in pediatric patients with PH. Ventilatory efficiency slope may be a useful noninvasive marker for disease severity.     

峰值氧耗量对非射血分数减低的心力衰竭患者预后评估的价值

目的:探讨心肺运动试验重要参数对非射血分数减低心力衰竭(HFr EF)预后评价的价值。方法:前瞻性入组2014年1月到2018年6月,我院诊断为非HFr EF患者,记录患者再入院及死亡事件,最后进行生存分析。结果:入选124例患者,平均随访(24±5)个月,10例患者死亡,32例患者因心力衰竭再住院治疗。心力衰竭组患者峰值氧耗量劣于正常健康对照组[(17.4±2.7)vs.(31.5±3.2)m L·kg^-1·min^-1,P<0.05]。事件组峰值氧耗量低于无事件组[(13.9±2.1)vs.(19.2±3.5)m L·kg^-1·min^-1,P<0.05]。多因素分析表明:峰值氧耗量是预测非HFr EF患者预后的指标(HR=0.81,95%CI:0.76~0.92,P<0.002)。结论:峰值氧耗量可以很好预测非HFr EF患者预后。     

室性心律失常对老年心力衰竭患者预后的影响

目的　探讨室性心律失常对心力衰竭老年患者预后的影响。方法　 180例心力衰竭老年患者行 2 4h动态心电图检查 ,随访 3个月。观察猝死与各种室性心律失常的关系。结果　 16 9例(93 9% )患者有室性心律失常。 2 4h >10 0 0个室性早搏 (PVCs)者 6 9例 (38 3% ) ,多形PVCs 34例(18 9% ) ,成对PVCs 6 6例 (36 7% )。非持续性室性心动过速 81例 (45 0 % ) ,随访 3个月 7例发生猝死 ,无心动过速的患者猝死 1例。结论　非持续性室性心动过速是心力衰竭老年患者猝死的危险因素     

Prognostic value of QT/RR slope in predicting mortality in patients with congestive heart failure

Introduction: Repolarization dynamics, reflecting adaptation of QT to changing heart rate, is considered a marker of unfavorable prognosis in patients with heart diseases. We aimed to evaluate the prognostic value of QT/RR slope in predicting total mortality (TM) and sudden death (SD) in patients with congestive heart failure (CHF). Methods and Results: In 651 sinus rhythm patients with CHF in NYHA class II–III enrolled in the MUSIC study, 24‐hour Holter monitoring was performed at enrollment to assess slope of the QTa/RR (QT apex) and QTe/RR (QTend) during the entire 24‐hour Holter recording and separately during day and night periods. Patients were followed for a median of 44 months, with the primary endpoint defined as TM and the secondary as SD. Analysis of repolarization dynamics was feasible in 542 patients (407M), mean age 63 years, 83% in NYHA class II, 49% with ischemic cardiomyopathy, with mean LVEF 37%. Mean value of QTa/RR slope was 0.172 and QTe/RR was 0.193. During the 44‐month follow‐up there were 119 deaths including 47 SD. Nonsurvivors were characterized by steeper QT/RR slopes. Increased QT/RR slopes during the daytime (>0.20 for QTa and >0.22 for QTe) were independently associated with increased TM in multivariate analysis after adjustment for clinical covariates with respective hazard ratios 1.57 and 1.58, P = 0.002. None of the dynamic repolarization parameters was associated with increased risk of SD in the entire population. Conclusions: Abnormal repolarization dynamics reflected as increased daytime QT/RR slopes is an independent risk stratifier of all‐cause mortality in patients with chronic heart failure     

Prognostic significance of PaO2/PaCO2 ratio in normotensive patients with pulmonary embolism

Introduction: Risk stratification remains controversial in patients with normotensive pulmonary embolism (PE). The debate has recently focused right ventricular dysfunction detected by echocardiography or spiral computed tomography (CT) and cardiac biomarkers. Objectives: The utility of the PaO₂/PaCO₂ ratio to predict the short‐term prognosis of PE is not currently known and that is the aim of the present study. Materials and Methods: This study retrospectively enrolled 99 (34 males, 65 females, 67 ± 15 years) consecutive patients with acute PE, diagnosed by spiral chest tomography pulmonary angiography (CTPA).On admission, cardiac troponin T (cTn‐T) was measured and on CTPA both right ventricle diameter and left ventricle diameter was calculated (RV/LV ratio). During the first 24 h after admission, all the patients had initial arterial blood gas collected under room air. Receiver‐operating characteristic (ROC) analysis was performed to determine the optimal PaO₂/PaCO₂, RV/LV ratio and cTn‐T cutoff level with regard to prognosis. Results: In‐hospital mortality was 12.1% and all‐cause 90‐day mortality was 15.2%. Ten of 15 patients who died had a PaO₂/PaCO₂ ≤ 1.8 based on ROC analysis (P < 0.014).The cutoff level of PaO₂/PaCO₂ ≤ 1.8 had a high negative predictive value of 93% for mortality. Multivariable analysis revealed that PaO₂/PaCO₂ ≤ 1.8 Hazard Ratio (HR): 16.8 [95% CI: 2.6–108, P < 0.003] was the most significant independent predictor, whereas cTn‐T, pO₂ < 60 mmHg and cardiac failure were nonsignificant factors. In addition, PaO₂/PaCO₂ ≤ 1.8 showed significant survival differences for overall mortality rates in Kaplan–Meier analysis (P < 0.012). Conclusion: The PaO₂/PaCO₂ measurement is a highly useful and practical measurement to predict prognosis in patients with acute PE. Moreover, it appears to be a more accurate predictor than RV/LV ratio and cTn‐T levels in patients with normotensive PE. Please cite this paper as: Ozsu S, Abul Y, Yilmaz I, Ozsu A, Oztuna F, Bulbul Y and Ozlu T. Prognostic significance of PaO₂/PaCO₂ ratio in normotensive patients with pulmonary embolism. Clin Respir J 2012; 6: 104–111.     

Effects of lisinopril in patients with heart failure and chronic atrial fibrillation

Although atrial fibrillation is common in patients with heart failure, patients with atrial fibrillation are often excluded from congestive heart failure trials or are not analyzed separately. Consequently, while the effect of angiotensin-converting enzyme inhibitors in patients with sinus rhythm is well established, the effect on patients with atrial fibrillation is unknown. The authors hypothesized that these agents might be particularly effective in this patient category, given their antiadrenergic properties and the importance of adequate rate control. Therefore, the effects of lisinopril 10 mg once daily were evaluated in 30 patients with congestive heart failure and chronic atrial fibrillation (mean age, 68 +/- 6 years) in a double-blind, randomized, placebo-controlled trial. All patients were in New York Heart Association class II or III and were stable on conventional therapy (digoxin, diuretics, nitrates). After 6 weeks, mean peak oxygen consumption increased from 14.7 +/- 3.4 to 15.9 +/- 2.9 mL/min/kg in the lisinopril group (P = .034). Plasma norepinephrine levels during exercise and at peak exercise tended to be lower when the patients were taking lisinopril (10.8 +/- 4.2 to 8.9 +/- 4.4 nmol/L and 16.3 +/- 9.2 to 14.3 +/- 7.7 nmol/L, P < .1). Heart rate during exercise and ambulatory monitoring was not significantly affected. Left ventricular fractional shortening tended to increase after lisinopril (23 +/- 7 to 27 +/- 9%, P = .073). Left atrial volume was unchanged, as were plasma atrial natriuretic peptide levels. After subsequent electrical cardioversion, treatment was continued for 6 more weeks, allowing assessment of the effect of lisinopril on maintenance of sinus rhythm; maintenance of sinus rhythm was 71% in the lisinopril group and 36% in the placebo group (P = NS). This study shows that treatment with an angiotensin- converting enzyme inhibitor improves peak oxygen consumption in patients with congestive heart failure and chronic atrial fibrillation. Attenuation of adrenergic drive during exercise may play a role in mediating this effect.     

Prognostic value of iodine-123 metaiodobenzylguanidine imaging in patients with heart failure

Abnormalities of myocardial sympathetic nerve function were reported in congestive heart failure (CHF). To assess myocardial sympathetic nerve function, we obtained metaiodobenzylguanidine (MIBG) images 15 min and 180 min after the injection of iodine-123 MIBG at a dose of 111 MBq and calculated the ratio of heart to mediastinum count (H/M) and the washout rates (WRs) in 59 consecutive patients with CHF and age-matched subjects without CHF (n=23). The plasma levels of B-type natriuretic peptide were measured. H/M ratio was significantly lower in the CHF group (1.8±0.9) than in the control group (2.6±0.4; P<0.01). WR was higher in the CHF group (38±4%) than in the control group (28±3%; P<0.01). H/M was inversely correlated with the plasma B-type natriuretic peptide (r=−0.46, P<0.05). Eighteen patients suffered cardiac events (two deaths, 16 hospitalizations) during a mean follow-up period of three years. Kaplan-Meier analysis showed that a low H/M was associated with a poor prognosis in patients with CHF. These findings indicate that the H/M ratio on MIBG imaging is a useful predictor of mortality and morbidity in patients with CHF.     

A critical re-appraisal of different ways of selecting ambulatory patients with suspected heart failure for echocardiography

BACKGROUND: ECG and BNP have been assessed as screening tests for LVSD and heart failure. However, echocardiography also provides information about valvular disease and LVH. We assessed how good these screening tests are in identifying whether the subsequent echocardiogram will have any significant abnormality. AIMS: To re-appraise the ECG and BNP as screening tests for echocardiography since there are important practical deficiencies in our current knowledge in this area. METHODS: General practitioners referred suspected heart failure patients for clinical assessment, echocardiography, electrocardiography, and BNP measurement. The accuracy of each screening test and combinations of screening tests were calculated for LVSD, heart failure, valvular disease, and LVH. RESULTS: The sensitivities of the ECG for LVSD, heart failure, LVH and valvular disease were 97%, 95%, 76%, and 69%, respectively. The corresponding figures for BNP were 86%, 82%, 59%, and 48%, respectively. When patients with atrial fibrillation and murmurs were excluded, the values for ECG were 94%, 87%, 53%, and 55%, while for BNP they were 83%, 73%, 50%, and 32%. CONCLUSIONS: ECG interpretation and BNP are adequate screening tests to detect LVSD or heart failure but fail to screen for other echocardiographic abnormalities, like valvular disease and LVH. This remains the case even if patients with atrial fibrillation or heart murmurs are excluded on the basis that they require echocardiography anyway.     

The sST2 level is an independent influencing factor associated with atrial fibrillation in heart failure patients: a case-control study

BackgroundMost heart failure (HF) patients were complicated with atrial fibrillation (AF). Previous study has reported a correlation between soluble suppression of tumorigenicity 2 (sST2) and HF. While the association between sST2 and AF in HF patients remains elusive, which will strengthen our understanding of sST2 in HF patients.MethodsIn the study, a case-control study was conducted with 306 HF patients enrolled from June 2019 to June 2020 at Beijing Anzhen Hospital. All the patients were divided into the following two groups, based on whether they AF complications prior to admission: (I) the HF group (patients with HF alone) and the HF-AF group (HF patients complicated with AF). Baseline data and sST2 levels were assessed and compared between the two groups, and the influencing factors associated with AF in HF patients were screened.ResultsThe sST2 level in the HF-AF group was 40.6 (25.9–53.6) ng/mL, which was significantly higher than that in the HF group [23.7 (16.3–35.9) ng/mL] (P<0.001). Correlation analysis showed that sST2 level in the HF-AF group was positively correlated with age (r=0.287, P=0.001), New York Heart Association (NYHA) grade (r=0.470, P<0.0001), left ventricular diameter (LVD) (r=0.311, P=0.001), serum creatinine (r=0.320, P<0.0001), NT-pro-brain natriuretic peptide (r=0.540, P<0.0001), and D-dimer (r=0.322, P<0.0001), and negatively correlated with left ventricular ejection fraction (LVEF) (r=−0.259, P=0.004), hemoglobin (r=−0.188, P=0.039), and glomerular filtration rate (r=−0.283, P=0.002). Logistic regression analysis results indicated that history of coronary heart disease [odds ratio (OR): 0.176, 95% confidence interval (CI): 0.081–0.380, P<0.0001], LVEF (OR: 0.956, 95% CI: 0.915–0.998, P=0.039), LVD (OR: 1.156, 95% CI: 1.059–1.261, P=0.001), left arterial diameter (OR: 0.761, 95% CI: 0.695–0.833, P<0.0001), and sST2 (OR: 0.942, 95% CI: 0.917–0.967, P<0.0001) were independent influencing factors associated with AF in HF patients.ConclusionsThe sST2 level is an independent influencing factor associated with AF in HF patients, which may favor to optimize the clinical strategies in the management of HF patients complicated with AF.     

Atrial fibrillation is associated with a lower exercise capacity in male chronic heart failure patients

Objective—To study the influence of atrial fibrillation on peak oxygen uptake (peak O₂) in chronic heart failure. An unfavourable effect of atrial fibrillation has been shown in several patient populations, but the results have not been consistent in chronic heart failure.
Methods—Data were analysed from male heart transplant candidates who were able to perform graded bicycle ergometry until exhaustion with respiratory gas analysis and measurement of heart rate. Patients in atrial fibrillation (n = 18) were compared with patients in sinus rhythm (n = 93).
Results—Age, weight, height, and aetiology of chronic heart failure did not differ significantly between the two groups. Cardiac catheterisation at supine rest showed that heart rate was comparable, but that stroke volume and cardiac output were lower (p < 0.05) in atrial fibrillation. Systolic and diastolic left ventricular function, assessed by radionuclide angiography at rest, were not significantly different. Peak O₂ (mean (SD): 13.8 (3.6) v 17.1 (5.6) ml/kg/min; p < 0.01) and peak work load (78 (27) v 98 (36) W; p < 0.05) were lower in the patients with atrial fibrillation, though respiratory gas exchange ratio and Borg score were similar in the two groups. Patients with atrial fibrillation had a higher heart rate sitting at rest before exercise (93 (16) v 84 (16) beats/min) and at peak effort (156 (23) v 140 (25) beats/min) (p < 0.05).
Conclusions—Atrial fibrillation is associated with a 20% lower peak O₂ in patients with chronic heart failure, suggesting that preserved atrial contraction or a regular rhythm, or both, are critical to maintain cardiac output and exercise performance.

Keywords: peak oxygen uptake;  exercise capacity;  chronic heart failure;  atrial fibrillation     

Dietary and blood antioxidants in patients with chronic heart failure. Insights into the potential importance of selenium in heart failure.

BACKGROUND: Chronic heart failure (CHF) seems to be associated with increased oxidative stress. However, the hypothesis that antioxidant nutrients may contribute to the clinical severity of the disease has never been investigated. AIMS: To examine whether antioxidant nutrients influence the exercise capacity and left ventricular function in patients with CHF. METHODS: Dietary intake and blood levels of major antioxidant nutrients were evaluated in 21 consecutive CHF patients and in healthy age- and sex-matched controls. Two indexes of the severity of CHF, peak exercise oxygen consumption (peak VO2) and left ventricular ejection fraction (LVEF), were measured and their relations with antioxidants were analysed. RESULTS: Whereas plasma alpha-tocopherol and retinol were in the normal range, vitamin C (P=0.005) and beta-carotene (P=0.01) were lower in CHF. However, there was no significant association between vitamins and either peak VO2 or LVEF. Dietary intake (P<0.05) and blood levels of selenium (P<0.0005) were lower in CHF. Peak VO2 (but not LVEF) was strongly correlated with blood selenium: r=0.76 by univariate analysis (polynomial regression) and r=0.87 (P<0.0005) after adjustment for age, sex and LVEF. CONCLUSIONS: Antioxidant defences are altered in patients with CHF. Selenium may play a role in the clinical severity of the disease, rather than in the degree of left ventricular dysfunction. Further studies are warranted to confirm the data in a large sample size and to investigate the mechanisms by which selenium and other antioxidant nutrients are involved in CHF.     

Increased left atrial volume index is an independent predictor of raised serum natriuretic peptide in patients with suspected heart failure but normal left ventricular ejection fraction: Implication for diagnosis of diastolic heart failure

BACKGROUND: Left atrial volume index (LAVI) is increasingly recognised as a relatively load-independent marker of left ventricular (LV) filling pressures. We assessed the capacity of LAVI to predict LV diastolic dysfunction in comparison with N-terminal pro B-type natriuretic peptide (NTproBNP) in patients with suspected heart failure and a normal ejection fraction (EF). METHODS: 137 patients with suspected heart failure (HF), referred from the community for echocardiography, prospectively underwent Doppler echocardiography, LAVI and NTproBNP estimation. Raised LAVI and reduced LV systolic function were defined as >26 ml/m2 and LV EF <50% respectively. RESULTS: Of 137 patients, 21 were excluded (2 with significant mitral valve disease and 19 with atrial fibrillation). Of the remaining 116 subjects, 92 showed normal LV systolic function. The univariate predictors of serum log NTproBNP were age (p < 0.001), LA dimension (p = 0.001), LAVI (p < 0.001), A wave (p = 0.001), E:A (p = 0.07) and septal wall thickness (p = 0.004). However on multivariate analysis, LAVI was found to be the most consistent and significant predictor of NTproBNP. The area under the curve of the receiver operating characteristic (ROC) curve for NTproBNP in detecting patients with LVEF > or = 50% and LAVI >26 ml/m2 was 0.81 (p < 0.0001) and for patients with LAVI > 26 ml/m2 with and without LVEF > or = 50% was 0.82 (p < 0.0001). CONCLUSION: This data confirms that LAVI on resting echocardiography, specifically in patients with suspected HF and normal LV systolic function is a powerful independent predictor of LV diastolic dysfunction as predicted by serum NTproBNP. In a population with a high suspicion of diastolic heart failure, LAVI may significantly contribute to diagnostic precision.