Comprehensive vasodilatation in women with acute heart failure: Novel insights from the GALACTIC randomized controlled trial

AIMS

Sex-specific differences in acute heart failure (AHF) are both relevant and underappreciated. Therefore, it is crucial to evaluate the risk/benefit ratio and the implementation of novel AHF therapies in women and men separately.

METHODS AND RESULTS

We performed a pre-defined sex-specific analysis in AHF patients randomized to a strategy of early intensive and sustained vasodilatation versus usual care in an international, multicentre, open-label, blinded endpoint trial. Inclusion criteria were AHF with increased plasma concentrations of natriuretic peptides, systolic blood pressure ≥100 mmHg, and plan for treatment in a general ward. Among 781 eligible patients, 288 (37%) were women. Women were older (median 83 vs. 76 years), had a lower body weight (median 64.5 vs. 77.6 kg) and lower estimated glomerular filtration rate (median 48 vs. 54 ml/min/1.73 m2 ). The primary endpoint, a composite of all-cause mortality or rehospitalization for AHF at 180 days, showed a significant interaction of treatment strategy and sex (p for interaction = 0.03; hazard ratio adjusted for female sex 1.62, 95% confidence interval 1.05-2.50; p = 0.03). The combined endpoint occurred in 53 women (38%) in the intervention group and in 35 (24%) in the usual care group. The implementation of rapid up-titration of renin-angiotensin-aldosterone system (RAAS) inhibitors was less successful in women versus men in the overall cohort and in patients with heart failure with reduced ejection fraction (median discharge % target dose in patients randomized to intervention: 50% in women vs. 75% in men).

CONCLUSION

Rapid up-titration of RAAS inhibitors was less successfully implemented in women possibly explaining their higher rate of all-cause mortality and rehospitalization for AHF.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, unique identifier NCT00512759.

Effect of a Strategy of Comprehensive Vasodilation vs Usual Care on Mortality and Heart Failure Rehospitalization Among Patients With Acute Heart Failure: The GALACTIC Randomized Clinical Trial

IMPORTANCE

Short-term infusions of single vasodilators, usually given in a fixed dose, have not improved outcomes in patients with acute heart failure (AHF).

OBJECTIVE

To evaluate the effect of a strategy that emphasized early intensive and sustained vasodilation using individualized up-titrated doses of established vasodilators in patients with AHF.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, open-label blinded-end-point trial enrolling 788 patients hospitalized for AHF with dyspnea, increased plasma concentrations of natriuretic peptides, systolic blood pressure of at least 100 mm Hg, and plan for treatment in a general ward in 10 tertiary and secondary hospitals in Switzerland, Bulgaria, Germany, Brazil, and Spain. Enrollment began in December 2007 and follow-up was completed in February 2019.

INTERVENTIONS

Patients were randomized 1:1 to a strategy of early intensive and sustained vasodilation throughout the hospitalization (n = 386) or usual care (n = 402). Early intensive and sustained vasodilation was a comprehensive pragmatic approach of maximal and sustained vasodilation combining individualized doses of sublingual and transdermal nitrates, low-dose oral hydralazine for 48 hours, and rapid up-titration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or sacubitril-valsartan.

MAIN OUTCOMES AND MEASURES

The primary end point was a composite of all-cause mortality or rehospitalization for AHF at 180 days.

RESULTS

Among 788 patients randomized, 781 (99.1%; median age, 78 years; 36.9% women) completed the trial and were eligible for primary end point analysis. Follow-up at 180 days was completed for 779 patients (99.7%). The primary end point, a composite of all-cause mortality or rehospitalization for AHF at 180 days, occurred in 117 patients (30.6%) in the intervention group (including 55 deaths [14.4%]) and in 111 patients (27.8%) in the usual care group (including 61 deaths [15.3%]) (absolute difference for the primary end point, 2.8% [95% CI, -3.7% to 9.3%]; adjusted hazard ratio, 1.07 [95% CI, 0.83-1.39]; P = .59). The most common clinically significant adverse events with early intensive and sustained vasodilation vs usual care were hypokalemia (23% vs 25%), worsening renal function (21% vs 20%), headache (26% vs 10%), dizziness (15% vs 10%), and hypotension (8% vs 2%).

CONCLUSIONS AND RELEVANCE

Among patients with AHF, a strategy of early intensive and sustained vasodilation, compared with usual care, did not significantly improve a composite outcome of all-cause mortality and AHF rehospitalization at 180 days.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00512759.

Sensitive cardiac troponin in the diagnosis and risk stratification of acute heart failure

BACKGROUND

The aim of our study was to investigate the diagnostic and prognostic value of a sensitive cardiac troponin I (s-cTnI) assay in patients with acute heart failure (AHF).

METHODS

Sensitive cardiac troponin I was measured in 667 consecutive patients at presentation to the emergency department with acute dyspnoea. Three s-cTnI strata were predefined: below the limit of detection (<0.01 μg L(-1) , undetectable), detectable but still within the normal range (0.01-0.027 μg L(-1) ) and increased (≥0.028 μg L(-1) , ≥99th percentile). The final diagnosis was adjudicated by two independent cardiologists blinded to the s-cTnI levels. Median follow-up in patients with AHF was 371 days.

RESULTS

Levels of s-cTnI were higher in patients with AHF (n = 377, 57%) compared to patients with noncardiac causes of acute dyspnoea (median 0.02 vs. <0.01 μg L(-1) , P < 0.001). In patients with AHF, in-hospital mortality increased with increasing s-cTnI in the three strata (2%, 5% and 14%, P < 0.001). One-year mortality also increased with increasing s-cTnI (21%, 33% and 47%, P < 0.001). s-cTnI remained an independent predictor of 1-year mortality [adjusted odds ratio 1.03 for each increase of 0.1 μg L(-1) , 95% confidence interval (CI) 1.02-1.05, P < 0.001] after adjustment for other risk factors including B-type natriuretic peptide. The net reclassification improvement was 68% (P < 0.001), and absolute integrated discrimination improvement was 0.18 (P < 0.001). The diagnostic accuracy of s-cTnI for the diagnosis of AHF as quantified by the area under the receiver operating characteristic curve was 0.78 (95% CI, 0.75-0.82).

CONCLUSIONS

Sensitive cardiac troponin I is a strong predictor of short- and long-term prognosis in AHF that helps to reclassify patients in terms of mortality risk. Detectable levels of s-cTnI, even within the normal range, are independently associated with mortality.

Plasma neutrophil gelatinase-associated lipocalin for the prediction of acute kidney injury in acute heart failure

Introduction

The accurate prediction of acute kidney injury (AKI) in patients with acute heart failure (AHF) is an unmet clinical need. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel sensitive and specific marker of AKI.

Methods

A total of 207 consecutive patients presenting to the emergency department with AHF were enrolled. Plasma NGAL was measured in a blinded fashion at presentation and serially thereafter. The potential of plasma NGAL levels to predict AKI was assessed as the primary endpoint. We defined AKI according to the AKI Network classification.

Results

Overall 60 patients (29%) experienced AKI. These patients were more likely to suffer from pre-existing chronic cardiac or kidney disease. At presentation, creatinine (median 140 (interquartile range (IQR), 91 to 203) umol/L versus 97 (76 to 132) umol/L, P < 0.01) and NGAL (114.5 (IQR, 67.1 to 201.5) ng/ml versus 74.5 (60 to 113.9) ng/ml, P < 0.01) levels were significantly higher in AKI compared to non-AKI patients. The prognostic accuracy for measurements obtained at presentation, as quantified by the area under the receiver operating characteristic curve was mediocre and comparable for the two markers (creatinine 0.69; 95%CI 0.59 to 0.79 versus NGAL 0.67; 95%CI 0.57 to 0.77). Serial measurements of NGAL did not further increase the prognostic accuracy for AKI. Creatinine, but not NGAL, remained an independent predictor of AKI (hazard ratio (HR) 1.12; 95%CI 1.00 to 1.25; P = 0.04) in multivariable regression analysis.

Conclusions

Plasma NGAL levels do not adequately predict AKI in patients with AHF.

Value of arterial blood gas analysis in patients with acute dyspnea: an observational study

Introduction

The diagnostic and prognostic value of arterial blood gas analysis (ABGA) parameters in unselected patients presenting with acute dyspnea to the Emergency Department (ED) is largely unknown.

Methods

We performed a post-hoc analysis of two different prospective studies to investigate the diagnostic and prognostic value of ABGA parameters in patients presenting to the ED with acute dyspnea.

Results

We enrolled 530 patients (median age 74 years). ABGA parameters were neither useful to distinguish between patients with pulmonary disorders and other causes of dyspnea nor to identify specific disorders responsible for dyspnea. Only in patients with hyperventilation from anxiety disorder, the diagnostic accuracy of pH and hypoxemia rendered valuable with an area under the receiver operating characteristics curve (AUC) of 0.86. Patients in the lowest pH tertile more often required admission to intensive care unit (28% vs 12% in the first tertile, P < 0.001) and had higher in-hospital (14% vs 5%, P = 0.003) and 30-day mortality (17% vs 7%, P = 0.002). Cumulative mortality rate was higher in the first (37%), than in the second (28%), and the third tertile (23%, P = 0.005) during 12 months follow-up. pH at presentation was an independent predictor of 12-month mortality in multivariable Cox proportional hazard analysis both for patients with pulmonary (P = 0.043) and non-pulmonary disorders (P = 0.038).

Conclusions

ABGA parameters provide limited diagnostic value in patients with acute dyspnea, but pH is an independent predictor of 12 months mortality.

Increasing B-type natriuretic peptide levels predict mortality in unselected haemodialysis patients

AIMS

Cardiac disease is the major cause of death in patients undergoing chronic haemodialysis. Recent studies have found that B-type natriuretic peptide (BNP) levels accurately reflect the cardiovascular burden of dialysis patients. However, the prognostic potential of BNP measurements in dialysis patients remains unknown.

METHODS AND RESULTS

The study included 113 chronic dialysis patients who were prospectively followed up. Levels of BNP were measured at baseline and every 6 months thereafter. The potential of baseline BNP and annual BNP changes to predict all-cause and cardiac mortality were assessed as endpoints. Median follow-up was 735 (354-1459) days; 35 (31%) patients died, 17 (15%) of them from cardiac causes. Baseline BNP levels were similar among survivors and non-survivors, and failed to predict all-cause and cardiac death. Cardiac death was preceded by a marked increase in BNP levels. In survivors BNP levels remained stable [median change: +175% (+20-+384%) vs. -14% (-35-+35%) over the 18 months preceding either death or the end of follow-up, P< 0.001]. Hence, annual BNP changes adequately predicted all-cause and cardiac death in the subsequent year {AUC(all-cause) = 0.70 [SD 0.05, 95% CI (0.60-0.81)]; AUC(cardiac) = 0.82 [SD 0.04, 95%CI (0.73-0.90)]}. A BNP increase of 40% provided the best cut-off level. Cox regression analysis confirmed that annual increases over 40% were associated with a seven-fold increased risk for all-cause and cardiac death.

CONCLUSIONS

Annual BNP increases above 40% predicted all-cause and cardiac death in the subsequent year. Hence, serially measuring BNP levels may present a novel tool for risk stratification and treatment guidance of end-stage renal disease patients on chronic dialysis.

Effect and clinical prediction of worsening renal function in acute decompensated heart failure

We aimed to establish the prevalence and effect of worsening renal function (WRF) on survival among patients with acute decompensated heart failure. Furthermore, we sought to establish a risk score for the prediction of WRF and externally validate the previously established Forman risk score. A total of 657 consecutive patients with acute decompensated heart failure presenting to the emergency department and undergoing serial creatinine measurements were enrolled. The potential of the clinical parameters at admission to predict WRF was assessed as the primary end point. The secondary end point was all-cause mortality at 360 days. Of the 657 patients, 136 (21%) developed WRF, and 220 patients had died during the first year. WRF was more common in the nonsurvivors (30% vs 41%, p = 0.03). Multivariate regression analysis found WRF to independently predict mortality (hazard ratio 1.92, p <0.01). In a single parameter model, previously diagnosed chronic kidney disease was the only independent predictor of WRF and achieved an area under the receiver operating characteristic curve of 0.60. After the inclusion of the blood gas analysis parameters into the model history of chronic kidney disease (hazard ratio 2.13, p = 0.03), outpatient diuretics (hazard ratio 5.75, p <0.01), and bicarbonate (hazard ratio 0.91, p <0.01) were all predictive of WRF. A risk score was developed using these predictors. On receiver operating characteristic curve analysis, the Forman and Basel prediction rules achieved an area under the curve of 0.65 and 0.71, respectively. In conclusion, WRF was common in patients with acute decompensated heart failure and was linked to significantly worse outcomes. However, the clinical parameters failed to adequately predict its occurrence, making a tailored therapy approach impossible.

Direct comparison of serial B-type natriuretic peptide and NT-proBNP levels for prediction of short- and long-term outcome in acute decompensated heart failure

Introduction

Monitoring treatment efficacy and assessing outcome by serial measurements of natriuretic peptides in acute decompensated heart failure (ADHF) patients may help to improve outcome.

Methods

This was a prospective multi-center study of 171 consecutive patients (mean age 80 73-85 years) presenting to the emergency department with ADHF. Measurement of BNP and NT-proBNP was performed at presentation, 24 hours, 48 hours and at discharge. The primary endpoint was one-year all-cause mortality; secondary endpoints were 30-days all-cause mortality and one-year heart failure (HF) readmission.

Results

During one-year follow-up, a total of 60 (35%) patients died. BNP and NT-proBNP levels were higher in non-survivors at all time points (all P < 0.001). In survivors, treatment reduced BNP and NT-proBNP levels by more than 50% (P < 0.001), while in non-survivors treatment did not lower BNP and NT-proBNP levels. The area under the ROC curve (AUC) for the prediction of one-year mortality increased during the course of hospitalization for BNP (AUC presentation: 0.67; AUC 24 h: 0.77; AUC 48 h: 0.78; AUC discharge: 0.78) and NT-proBNP (AUC presentation: 0.67; AUC 24 h: 0.73; AUC 48 h: 0.75; AUC discharge: 0.77). In multivariate analysis, BNP at 24 h (1.02 [1.01-1.04], P = 0.003), 48 h (1.04 [1.02-1.06], P < 0.001) and discharge (1.02 [1.01-1.03], P < 0.001) independently predicted one-year mortality, while only pre-discharge NT-proBNP was predictive (1.07 [1.01-1.13], P = 0.016). Comparable results could be obtained for the secondary endpoint 30-days mortality but not for one-year HF readmissions.

Conclusions

BNP and NT-proBNP reliably predict one-year mortality in patients with ADHF. Prognostic accuracy of both biomarker increases during the course of hospitalization. In survivors BNP levels decline more rapidly than NT-proBNP levels and thus seem to allow earlier assessment of treatment efficacy. Ability to predict one-year HF readmission was poor for BNP and NT-proBNP.

Trial registration

ClinicalTrials.gov identifier: NCT00514384.

Copeptin and risk stratification in patients with acute dyspnea

Introduction

The identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of Copeptin, the C-terminal part of the vasopressin prohormone alone and combined to N-terminal pro B-type natriuretic peptide (NT-proBNP) in patients with acute dyspnea.

Methods

We conducted a prospective, observational cohort study in the emergency department of a university hospital and enrolled 287 patients with acute dyspnea.

Results

Copeptin levels were elevated in non-survivors (n = 29) compared to survivors at 30 days (108 pmol/l, interquartile range (IQR) 37 to 197 pmol/l) vs. 18 pmol/l, IQR 7 to 43 pmol/l; P < 0.0001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.83 (95% confidence interval (CI) 0.76 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for Copeptin, NT-proBNP and BNP, respectively (Copeptin vs. NTproBNP P = 0.21; Copeptin vs. BNP P = 0.002). When adjusted for common cardiovascular risk factors and NT-proBNP, Copeptin was the strongest independent predictor for short-term mortality in all patients (HR 3.88 (1.94 to 7.77); P < 0.001) and especially in patients with acute decompensated heart failure (ADHF) (HR 5.99 (2.55 to 14.07); P < 0.0001). With the inclusion of Copeptin to the adjusted model including NTproBNP, the net reclassification improvement (NRI) was 0.37 (P < 0.001). An additional 30% of those who experienced events were reclassified as high risk, and an additional 26% without events were reclassified as low risk.

Conclusions

Copeptin is a new promising prognostic marker for short-term mortality independently and additive to natriuretic peptide levels in patients with acute dyspnea.

Effect of oral β-blocker on short and long-term mortality in patients with acute respiratory failure: results from the BASEL-II-ICU study

INTRODUCTION

Acute respiratory failure (ARF) is responsible for about one-third of intensive care unit (ICU) admissions and is associated with adverse outcomes. Predictors of short- and long-term outcomes in unselected ICU-patients with ARF are ill-defined. The purpose of this analysis was to determine predictors of in-hospital and one-year mortality and assess the effects of oral beta-blockers in unselected ICU patients with ARF included in the BASEL-II-ICU study.

METHODS

The BASEL II-ICU study was a prospective, multicenter, randomized, single-blinded, controlled trial of 314 (mean age 70 (62 to 79) years) ICU patients with ARF evaluating impact of a B-type natriuretic peptide- (BNP) guided management strategy on short-term outcomes.

RESULTS

In-hospital mortality was 16% (51 patients) and one-year mortality 41% (128 patients). Multivariate analysis assessed that oral beta-blockers at admission were associated with a lower risk of both in-hospital (HR 0.33 (0.14 to 0.74) P = 0.007) and one-year mortality (HR 0.29 (0.16 to 0.51) P = 0.0003). Kaplan-Meier analysis confirmed the lower mortality in ARF patients when admitted with oral beta-blocker and further shows that the beneficial effect of oral beta-blockers at admission holds true in the two subgroups of patients with ARF related to cardiac or non-cardiac causes. Kaplan-Meier analysis also shows that administration of oral beta-blockers before hospital discharge gives striking additional beneficial effects on one-year mortality.

CONCLUSIONS

Established beta-blocker therapy appears to be associated with a reduced mortality in ICU patients with acute respiratory failure. Cessation of established therapy appears to be hazardous. Initiation of therapy prior to discharge appears to confer benefit. This finding was seen regardless of the cardiac or non-cardiac etiology of respiratory failure.

TRIAL REGISTRATION

clinicalTrials.gov Identifier: NCT00130559.

Interleukin family member ST2 and mortality in acute dyspnoea

OBJECTIVES

The study objective was to investigate the prognostic utility and patient-specific characteristics of ST2 (suppression of tumorigenicity 2), assessed with a novel sensitive assay.

BACKGROUND

Suppression of tumorigenicity 2 signalling has been shown to be associated with death in cardiac and pulmonary diseases.

DESIGN/SUBJECTS

In an international multicentre cohort design, we prospectively enrolled 1091 patients presenting with acute dyspnoea to the emergency department (ED). ST2 was measured in a blinded fashion using a novel assay and compared to B-type natriuretic peptide (BNP) and NT-proBNP. The primary end-point was mortality within 30 days and 1 year. The prognostic value of ST2 was evaluated in comparison and in addition to BNP and NT-proBNP.

RESULTS

Suppression of tumorigenicity 2 concentrations was higher amongst decedents than among survivors (median 85 vs. 43 U mL⁻¹, P < 0.001) and also higher in patients with impaired left ventricular ejection fraction (LVEF) when compared with preserved LVEF (P < 0.001). In receiver operator characteristics analysis, the area under the curve (AUC) for ST2, BNP and NT-proBNP to predict 30-day and 1-year mortality were 0.76, 0.63 and 0.71, and 0.72, 0.71 and 0.73, respectively. The combinations of ST2 with BNP or NT-proBNP improved prediction of mortality provided by BNP or NT-proBNP alone. After multivariable adjustment, ST2 values above the median (50 U mL⁻¹) significantly predicted 1-year mortality (HR 2.3, P < 0.001).

CONCLUSION

In patients presenting to the ED with acute dyspnoea, ST2 is a strong and independent predictor of 30-day and 1-year mortality and might improve risk stratification already provided by BNP or NT-proBNP.

Haemodynamic and arrhythmic effects of moderately cold (22 degrees C) water immersion and swimming in patients with stable coronary artery disease and heart failure

AIMS

Data on moderately cold water immersion and occurrence of arrhythmias in chronic heart failure (CHF) patients are scarce.

METHODS AND RESULTS

We examined 22 male patients, 12 with CHF [mean age 59 years, ejection fraction (EF) 32%, NYHA class II] and 10 patients with stable coronary artery disease (CAD) without CHF (mean age 65 years, EF 52%). Haemodynamic effects of water immersion and swimming in warm (32 degrees C) and moderately cold (22 degrees C) water were measured using an inert gas rebreathing method. The occurrence of arrhythmias during water activities was compared with those measured during a 24 h ECG recording. Rate pressure product during water immersion up to the chest was significantly higher in moderately cold (P = 0.043 in CHF, P = 0.028 in CAD patients) compared with warm water, but not during swimming. Rate pressure product reached 14200 in CAD and 12 400 in CHF patients during swimming. Changes in cardiac index (increase by 5-15%) and oxygen consumption (increase up to 20%) were of similar magnitude in moderately cold and warm water. Premature ventricular contractions (PVCs) increased significantly in moderately cold water from 15 +/- 41 to 76 +/- 163 beats per 30 min in CHF (P = 0.013) but not in CAD patients (20 +/- 33 vs. 42 +/- 125 beats per 30 min, P = 0.480). No ventricular tachycardia was noted.

CONCLUSION

Patients with compensated CHF tolerate water immersion and swimming in moderately cold water well. However, the increase in PVCs raises concerns about the potential danger of high-grade ventricular arrhythmias.

Natriuretic peptides and their evolving clinical applications

Natriuretic peptides (NP) are quantitative plasma biomarkers of heart failure, which are widely used in clinical practice in many countries. NP levels are accurate in the diagnosis of heart failure in patients presenting with dyspnea. The use of NP improves patient management and reduces total treatment costs in patients with dyspnea. As NP levels quantify disease severity in patients with established heart failure, NP levels are powerful predictors of outcome in predicting death and rehospitalization. NP-guided therapy may improve morbidity in patients with chronic heart failure. Although NP levels also risk-stratify patients with many other conditions such as stable or unstable coronary artery disease, pulmonary embolism and community-acquired pneumonia, there is insufficient evidence on how patient outcome could be altered in patients identified as high risk.

Use of myeloperoxidase for risk stratification in acute heart failure

BACKGROUND

Myeloperoxidase (MPO) is a biomarker of inflammation and oxidative stress produced by neutrophils, monocytes, and endothelial cells. Concentrations of MPO predict mortality in patients with chronic heart failure. This study sought to investigate the diagnostic accuracy and prognostic value of MPO in patients with acute heart failure (AHF).

METHODS

We prospectively enrolled 667 patients presenting to the emergency department with dyspnea and observed them for 1 year. MPO and B-type natriuretic peptide (BNP) were measured at presentation. Two independent cardiologists adjudicated final discharge diagnoses.

RESULTS

MPO concentrations were similar in patients with AHF (n = 377, median 139 pmol/L) and patients with noncardiac causes of dyspnea (n = 290, median 150 pmol/L, P = 0.26). The diagnostic accuracy of MPO for AHF was limited [area under the ROC curve (AUC) 0.53] and inferior to that of BNP (AUC 0.95, P < 0.001). In patients with AHF, MPO concentrations above the lowest tertile (MPO >99 pmol/L) were associated with significantly increased 1-year mortality (hazard ratio 1.58, P = 0.02). The combination of MPO (< or = 99 vs >99 pmol/L) and BNP (median of < or = 847 vs >847 ng/L) improved the prediction of 1-year mortality (hazard ratio 2.80 for both variables increased vs both low, P < 0.001). After adjustment for cardiovascular risk factors in multivariable Cox proportional hazard analysis, increases in MPO contributed significantly toward the prediction of 1-year mortality (hazard ratio 1.51, P = 0.045).

CONCLUSIONS

MPO is an independent predictor of 1-year mortality in AHF, is additive to BNP, and could be helpful in identifying patients with a favorable prognosis despite increased BNP concentrations.

Central venous pressure at emergency room presentation predicts cardiac rehospitalization in patients with decompensated heart failure

AIMS

To investigate the relationship between central venous pressure (CVP) at presentation to the emergency room (ER) and the risk of cardiac rehospitalization and mortality in patients with decompensated heart failure (DHF).

METHODS AND RESULTS

Central venous pressure was determined non-invasively using high-resolution compression sonography at presentation in 100 patients with DHF. Cardiac hospitalizations and cardiac and all-cause mortality were assessed as a function of continuous CVP levels and predefined CVP categories (low <6 cm H(2)O, intermediate 6-23 cm H(2)O, and high >23 cm H(2)O). Endpoints were adjudicated blinded to CVP. At presentation, mean age was 78 +/- 11 years, 60% of patients were male, mean B-type natriuretic peptide level was 1904 +/- 1592 pg/mL, and mean CVP was 13.7 +/- 7.0 cm H(2)O (range 0-33). During follow-up (median 12 months), 25 cardiac rehospitalizations, 26 cardiac deaths, and 7 non-cardiac deaths occurred. Univariate and stepwise multivariate Cox regression analysis revealed an independent relationship between CVP and cardiac rehospitalization (HR 1.09, 95% CI 1.01-1.18, P = 0.034). Kaplan-Meier analyses confirmed a stepwise increase in cardiac rehospitalization for low-to-high CVP (log-rank test P = 0.015). No association between CVP and (cardiac) mortality was detectable.

CONCLUSION

Central venous pressure at ER presentation in patients with DHF is an independent predictor of cardiac rehospitalization but not of cardiac and all-cause mortality.

Impact of a high-dose nitrate strategy on cardiac stress in acute heart failure: a pilot study

BACKGROUND

Intravenous nitrate therapy has been shown to improve short-term outcome of acute heart failure patients treated in the intensive care unit. The potential of a noninvasive high-dose nitrate strategy in the Emergency Department and the general ward remains unknown.

METHODS

A total of 128 consecutive acute heart failure patients were either treated with standard therapy or high-dose sublingual and transdermal nitrates on top of standard of care treatment. Cardiac recovery, quantified by B-type natriuretic peptide (BNP) levels during the first 48 h, was the primary endpoint. Secondary endpoints ascertained the safety of the nitrate therapy.

RESULTS

The high nitrate group received higher doses of nitrates during the first 48 h compared to the standard therapy group [82.4 mg (46.2-120.6) vs. 20 mg (10-30) respectively, P < 0.001]. The amount of diuretics given in both groups was similar. BNP levels decreased in all patients (P < 0.0001). However, the BNP decrease was larger in the high-dose nitrate group (P < 0.0001). The larger decrease in BNP in the high-dose nitrate group was already apparent 12 h after the initiation of treatment. After 48 h BNP values decreased by an average of 29 +/- 4.9% in the high-dose nitrate strategy group compared to 15 +/- 5.4% during standard therapy. There was a strong trend towards fewer ICU admissions in the high-dose nitrate group [high-dose nitrates: 2 cases (4%) vs. standard therapy: 9 cases (13%); P = 0.06]. During the study period, no intergroup changes were observed in blood pressure, RIFLE classes of acute kidney injury or troponin T. In-hospital and 90-day outcome was similar amongst the two groups.

CONCLUSIONS

A noninvasive high-dose nitrate strategy on top of standard therapy is safe and notably accelerates cardiac recovery in patients observed on the general ward.

Comparison of midregional pro-atrial natriuretic peptide with N-terminal pro-B-type natriuretic peptide in the diagnosis of heart failure

OBJECTIVES

The concentration of atrial natriuretic peptide (ANP) in the circulation is approximately 10- to 50- fold higher than B-type natriuretic peptide (BNP). We sought to compare the accuracy of midregional pro-atrial natriuretic peptide (MRproANP) measured with a novel sandwich immunoassay with N-terminal pro-B-type natriuretic peptide (NTproBNP) in the diagnosis of heart failure.

DESIGN

The diagnosis of heart failure was adjudicated by two independent cardiologists using all available clinical data (including BNP levels) in 287 consecutive patients presenting with dyspnoea to the emergency department (ED). MRproANP and NTproBNP levels were determined at presentation in a blinded fashion.

RESULTS

Heart failure was the adjudicated final diagnosis in 154 patients (54%). Median MRproANP was significantly higher in patients with heart failure as compared to patients with other causes of dyspnoea (400 vs. 92 pmol L(-1), P < 0.001). The diagnostic accuracy of MRproANP was very high with an area under the receiver operating characteristic curve of 0.92 and was comparable with that of NTproBNP (0.92, P = 0.791). Moreover, MRproANP provided incremental diagnostic information to BNP and NTproBNP in patients presenting with BNP levels in the grey zone between 100 and 500 pg mL(-1).

CONCLUSION

Midregional pro-atrial natriuretic peptide is as accurate in the diagnosis of heart failure as NTproBNP. MRproANP seems to provide incremental information on top of BNP or NT-proBNP in some subgroups and should be further investigated in other studies.

Cardiovascular biomarkers in the ICU

PURPOSE OF REVIEW

Natriuretic peptides are markers of heart failure and/or cardiac dysfunction that provide useful diagnostic and prognostic information in patients with dyspnea and/or respiratory failure in the emergency department. Cardiac troponins (cTn) have markedly simplified the diagnosis of myocardial infarction. In critically ill patients, conditions like coexisting organ dysfunction multiorgan involvement or altered synthesis/clearance may confound interpretation of designated biomarkers, including natriuretic peptides and cTn. This review focuses on recently published articles relating to the use of natriuretic peptides and cTn in critically ill patients.

RECENT FINDINGS

One new study addresses diagnostic utility of B-type natriuretic peptide to distinguish low-pressure pulmonary edema (acute lung injury/acute respiratory distress syndrome) from high-pressure (cardiogenic) pulmonary edema. Other studies highlight the prognostic value of natriuretic peptides either in unselected and general noncardiac ICU patients and reveal an important reason for elevated B-type natriuretic peptide levels in septic shock.Interesting data focusing on diagnostic and prognostic ability of systematic cTn screening measurements in ICU patients became available.

SUMMARY

Recent studies confirm the excellent prognostic value of natriuretic peptide measurements in ICU patients. Diagnostic properties of natriuretic peptide in ICU patients still remain ambiguous and require further evaluation. Systematic screening with cTn reveals more myocardial infarctions and provides important prognostic information.

What anesthesiologists should know about B-type natriuretic peptide

Natriuretic peptides (NPs), particularly B-type natriuretic peptide (BNP) and N-terminal pro BNP (NT-proBNP), are widely used as markers of cardiac wall stress and heart failure (HF) in daily clinical practice. The measurement of NPs became a part of national and international cardiovascular guidelines for the diagnosis and treatment of HF. NP measurement improves diagnosis and management and helps to predict outcome in patients presenting with acute dyspnea in the Emergency Department. Additionally, NPs are of special interest for anesthesiologists. This includes improved management of Intensive Care Unit patients with respiratory failure and preoperative risk assessment. This paper reviews and highlights the use of NPs in clinical practice focusing on issues that may be of particular interest to anesthesiologists.

Determinants of absolute and relative exercise-induced changes in B-type natriuretic peptides

BACKGROUND

Exercise is associated with changes in circulating B-type natriuretic peptide (BNP) and N-terminal-proBNP (NT-proBNP). However, the biological relevance of this phenomenon is poorly examined. We sought to assess determinants of absolute (Δ) and relative (Δ%) exercise-induced changes in BNP and NT-proBNP.

METHODS

BNP (n = 418) and NT-proBNP (n = 478) at rest and peak exercise were measured in patients undergoing symptom-limited cycle ergometer tests. Multivariate logistic regression was performed to identify predictors of high ΔBNP/ΔNT-proBNP and high ΔBNP/Δ%NT-proBNP defined as their highest quartiles (Q4).

RESULTS

The median (interquartile range) ΔBNP and ΔNT-proBNP was 12 (0-28) pg/ml and 7 (2-21) pg/ml respectively, and Δ%BNP and Δ%NT-proBNP was 21 (0-46) % and 7 (3-12) % respectively. Higher BNP [odds ratio (OR) 3.92 per ln unit; p < 0.001] or NT-proBNP [OR 4.88 per ln unit; p<0.001] at rest was the strongest predictor of ΔBNP in Q4 (≥ 28 pg/ml) or ΔNT-proBNP in Q4 (≥ 21 pg/ml). In contrast, higher maximal work rate expressed as the percentage of the predicted value (OR 1.015 per %; p = 0.007) was the only independent predictor of Δ%BNP in Q4 (≥ 46%), and lower resting heart rate (OR 0.97 per bpm; p = 0.001) and lower age (OR 0.95 per year; p = 0.001) were the only independent predictors of Δ%NT-proBNP in Q4 (≥ 12%).

CONCLUSIONS

Higher ΔBNP and ΔNT-proBNP primarily reflected higher BNP and NT-proBNP plasma levels at rest. In contrast, higher Δ%BNP and Δ%NT-proBNP were associated with several prognostically favorable features, indicating that higher Δ%BNP and Δ%NT-proBNP may be markers of health rather than disease.

Diagnostic and prognostic value of uric acid in patients with acute dyspnea

BACKGROUND

Uric acid was shown to predict outcome in patients with stable chronic heart failure. Its impact in patients admitted in the Emergency Department with acute dyspnea, however, remains unknown.

METHODS

We prospectively investigated the diagnostic and prognostic value of uric acid in 743 unselected patients presenting to the Emergency Department with acute dyspnea.

RESULTS

Uric acid at admission was higher in patients with acute decompensated heart failure (51% of the cohort) as compared with patients with noncardiac causes of dyspnea (median, 447 micromol/L vs 340 micromol/L, P <.001). The area under the receiver operating characteristic curve for the accuracy to detect acute decompensated heart failure was inferior for uric acid (0.70) than for B-type natriuretic peptide (area under the receiver operating characteristic curve 0.91, P <.001). Patients in the highest uric acid tertile more often required admission to the hospital (92% vs 74% in the first tertile, P <.001) and had higher in-hospital mortality (13% vs 4% in the first tertile, P <.001). Cumulative 24-month mortality rates were 28% in the first, 31% in the second, and 50% in the third tertile (P <.001). After adjustment in multivariable Cox proportional hazard analysis, uric acid predicted 24-month mortality independently of B-type natriuretic peptide (P=.003).

CONCLUSIONS

Our study first shows that uric acid, measured at Emergency Department admission or hospital discharge, is a powerful predictor of long-term outcome in dyspneic patients.

Early diagnosis of myocardial infarction with sensitive cardiac troponin assays

BACKGROUND

The rapid and reliable diagnosis of acute myocardial infarction is a major unmet clinical need.

METHODS

We conducted a multicenter study to examine the diagnostic accuracy of new, sensitive cardiac troponin assays performed on blood samples obtained in the emergency department from 718 consecutive patients who presented with symptoms suggestive of acute myocardial infarction. Cardiac troponin levels were determined in a blinded fashion with the use of four sensitive assays (Abbott-Architect Troponin I, Roche High-Sensitive Troponin T, Roche Troponin I, and Siemens Troponin I Ultra) and a standard assay (Roche Troponin T). The final diagnosis was adjudicated by two independent cardiologists.

RESULTS

Acute myocardial infarction was the adjudicated final diagnosis in 123 patients (17%). The diagnostic accuracy of measurements obtained at presentation, as quantified by the area under the receiver-operating-characteristic curve (AUC), was significantly higher with the four sensitive cardiac troponin assays than with the standard assay (AUC for Abbott-Architect Troponin I, 0.96; 95% confidence interval [CI], 0.94 to 0.98; for Roche High-Sensitive Troponin T, 0.96; 95% CI, 0.94 to 0.98; for Roche Troponin I, 0.95; 95% CI, 0.92 to 0.97; and for Siemens Troponin I Ultra, 0.96; 95% CI, 0.94 to 0.98; vs. AUC for the standard assay, 0.90; 95% CI, 0.86 to 0.94). Among patients who presented within 3 hours after the onset of chest pain, the AUCs were 0.93 (95% CI, 0.88 to 0.99), 0.92 (95% CI, 0.87 to 0.97), 0.92 (95% CI, 0.86 to 0.99), and 0.94 (95% CI, 0.90 to 0.98) for the sensitive assays, respectively, and 0.76 (95% CI, 0.64 to 0.88) for the standard assay. We did not assess the effect of the sensitive troponin assays on clinical management.

CONCLUSIONS

The diagnostic performance of sensitive cardiac troponin assays is excellent, and these assays can substantially improve the early diagnosis of acute myocardial infarction, particularly in patients with a recent onset of chest pain. (ClinicalTrials.gov number, NCT00470587.)

Midregional pro-adrenomedullin in addition to b-type natriuretic peptides in the risk stratification of patients with acute dyspnea: an observational study

INTRODUCTION

The identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of the newly described midregional fragment of the pro-Adrenomedullin molecule (MR-proADM) alone and combined to B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) in patients with acute dyspnea.

METHODS

We conducted a prospective, observational cohort study in the emergency department of a University Hospital and enrolled 287 unselected, consecutive patients (48% women, median age 77 (range 68 to 83) years) with acute dyspnea.

RESULTS

MR-proADM levels were elevated in non-survivors (n = 77) compared to survivors (median 1.9 (1.2 to 3.2) nmol/L vs. 1.1 (0.8 to 1.6) nmol/L; P < 0.001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.81 (95% CI 0.73 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for MR-proADM, NT-proBNP and BNP, respectively (MRproADM vs. NTproBNP P = 0.38; MRproADM vs. BNP P = 0.009). For one-year mortality the AUC were 0.75 (95% CI 0.69 to 0.81), 0.75 (95% CI 0.68 to 0.81), 0.69 (95% CI 0.62 to 0.76) for MR-proADM, NT-proBNP and BNP, respectively without any significant difference. Using multivariate linear regression analysis, MR-proADM strongly predicted one-year all-cause mortality independently of NT-proBNP and BNP levels (OR = 10.46 (1.36 to 80.50), P = 0.02 and OR = 24.86 (3.87 to 159.80) P = 0.001, respectively). Using quartile approaches, Kaplan-Meier curve analyses demonstrated a stepwise increase in one-year all-cause mortality with increasing plasma levels (P < 0.0001). Combined levels of MR-proADM and NT-proBNP did risk stratify acute dyspneic patients into a low (90% one-year survival rate), intermediate (72 to 82% one-year survival rate) or high risk group (52% one-year survival rate).

CONCLUSIONS

MR-proADM alone or combined to NT-proBNP has a potential to assist clinicians in risk stratifying patients presenting with acute dyspnea regardless of the underlying disease.

B-type natriuretic peptide and C-terminal-pro-endothelin-1 for the prediction of severely impaired peak oxygen consumption

OBJECTIVE

To assess the utility of B-type natriuretic peptide (BNP) and C-terminal-pro-endothelin-1 (CT-proET-1) to predict a severely impaired peak oxygen consumption (peak VO(2), < 14 mL kg(-1) min(-1)) in patients referred for cardiopulmonary exercise testing.

DESIGN

Cross-sectional study.

SETTING

Tertiary care center.

METHODS

Peak VO(2), BNP and CT-proET-1 were assessed in 141 consecutive patients referred for cardiopulmonary exercise testing.

RESULTS

B-type natriuretic peptide [median (interquartile range) 48 (38-319) vs. 33 (15-86) pg mL(-1); P = 0.002] and CT-proET-1 [87 (76-95) vs. 60 (52-74) pmol L(-1); P < 0.001] were higher in patients with a peak VO(2) < 14 mL kg(-1) min(-1) (n = 30) than in those with a peak VO(2) > or = 14 mL kg(-1) min(-1) (n = 111). CT-pro-ET-1 had a higher area under the receiver-operator-characteristics curve (AUC) to predict a peak VO(2) < 14 mL kg(-1) min(-1) than BNP (0.79 vs. 0.68; P = 0.04). The optimal BNP cut-off of 37.2 pg mL(-1) had a sensitivity of 80% and a specificity of 56%. The optimal CT-proET-1 cut-off of 74.4 pmol L(-1) had a sensitivity of 80% and specificity of 76%. A five-item score composed of body mass index, diabetes, forced expiratory volume within the first second, alveolo-arterial oxygen pressure difference, and BNP had an AUC of 0.88 to predict a peak VO(2) < 14 mL kg(-1) min(-1). Adding CT-proET-1 to the score resulted in an AUC of 0.92.

CONCLUSIONS

C-terminal-pro-endothelin-1 is superior to BNP for the prediction of a peak VO(2) < 14 mL kg(-1) min(-1) in patients referred for CPET. A score incorporating body mass index, diabetes status, spirometry, blood gases, BNP and CT-proET-1 improves the prediction of a peak VO(2) < 14 mL kg(-1) min(-1) based on single biomarkers.

Percutaneous coronary intervention versus coronary artery bypass grafting as primary revascularization in patients with acute coronary syndrome

New European Society of Cardiology/American College of Cardiology guidelines classify patients with acute coronary syndrome and increased cardiac troponins as non-ST-segment elevation myocardial infarction (NSTEMI) who would have been classified as unstable angina pectoris (UAP) using the older World Health Organization (WHO) definition. The optimal revascularization strategy in these patients is poorly defined. This prospective cohort study included 1,024 consecutive patients with acute coronary syndrome classified as UAP, NSTEMI according to the WHO definition (WHO NSTEMI), and NSTEMI additionally identified by the novel European Society of Cardiology/American College of Cardiology definition (additional NSTEMI). All patients underwent coronary angiography within 24 hours and were treated with immediate percutaneous coronary intervention (PCI) or early coronary artery bypass grafting (CABG). The primary end point was all-cause mortality during follow-up of 36 months. Patients with additional NSTEMI showed excessive cumulative 3-year mortality if undergoing CABG (hazard ratio 5.9, 95% confidence interval 2.7 to 13.1, p <0.001). In patients with UAP or WHO NSTEMI, mortality was similar in the CABG and PCI groups. In conclusion, in the absence of randomized trials specifically including patients with additional NSTEMI, the excessive mortality observed with CABG in this cohort study suggested that PCI may be the preferable revascularization strategy in this subgroup.

The use of B-type natriuretic peptide in the management of patients with atrial fibrillation and dyspnea

The utility of B-type natriuretic peptide (BNP) testing in patients with atrial fibrillation (AF) is poorly defined. We analyzed patients (n=452) included in the BNP for Acute Shortness of Breath Evaluation (BASEL) study. Patients were randomly assigned to a diagnostic strategy with or without the use of BNP. Ninety-nine patients presented with AF (n=48 BNP group; n=51 control group). Although comparable with respect to gender and cardiopulmonary comorbidity, patients with AF were older and more often had heart failure as the cause of dyspnea. In addition, patients with AF had higher in-hospital mortality (13% versus 6%, P=0.012). The use of BNP significantly reduced time to discharge (BNP group median 8 days [1-16] versus 12 days [IQR 4-21] control group; P=0.046) in patients with AF. Initial total treatment costs (median) were $4239 [769-7422] in the BNP group and $5940 [4024-10848] in the control group (P=0.041). These benefits were maintained after 90 days: patients in the BNP group had spent fewer days in hospital (10 days [2-21] versus 15 days [IQR 9-27]; P=0.022) and induced lower total treatment costs ($4790 [1260-9387] versus $7179 [4311-13173]; P=0.016). In conclusion, the use of BNP seems to improve the management of patients with AF presenting with dyspnea.

Medical and Economic Long-term Effects of B-Type Natriuretic Peptide Testing in Patients with Acute Dyspnea

Background: The objective of this prospective study was to assess the medical and economic long-term effects of using B-type natriuretic peptide (BNP) concentrations in the management of patients with acute dyspnea.

Methods: We performed follow-up analysis of the B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation, a randomized study including 452 patients who presented to the emergency department with acute dyspnea. Participants were randomly assigned to a diagnostic strategy involving the rapid measurement of BNP concentrations (n = 225) or standard assessment (n = 227). Mortality was assessed at 720 days, morbidity and economic data at 360 days.

Results: BNP testing induced several important changes in initial patient management, including a reduction in the initial hospital admission rate, the use of intensive care, and initial time to discharge. At 720 days, 172 deaths had occurred. Cumulative all-cause 720-day mortality was not different between the BNP group (37%) and the control group (36%, P = 0.6). Morbidity as reflected by days spent in-hospital at 360 days was significantly lower in the BNP group [median 12 days ([interquartile range 2–28 days)] compared with the control group [median 16 (7–32)] days, P = 0.025]. Functional status was similar in both groups. Economic outcome as quantified by total treatment cost at 360 days was significantly improved in the BNP group (mean $10 144 vs $12 748 in the control group, P = 0.008).

Conclusions: Rapid BNP testing in patients with acute dyspnea has no effect on long-term mortality. However, morbidity as quantified by days spent in-hospital and economic outcome are still improved at 360 days.

QRS and QTc interval prolongation in the prediction of long-term mortality of patients with acute destabilised heart failure

OBJECTIVES

To quantify the prognostic utility of QRS and QTc interval prolongation in patients presenting with acute destabilised heart failure (ADHF) to the emergency department (ED).

DESIGN

Prospective cohort study among patients enrolled in the B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation (BASEL) study. QRS and QT intervals were measured in 173 consecutive patients with ADHF. QT interval was corrected using the Bazett formula. The primary end point was all-cause mortality during the 720-day follow-up.

RESULTS

QRS interval was prolonged (> or =120 ms) in 27% of patients, and QTc interval was prolonged (> or =440 ms) in 72% of patients. Baseline demographic and clinical characteristics were comparable in patients with normal and prolonged QRS or QTc intervals. A total of 78 patients died during follow-up. Interestingly, the 720-day mortality was similar in patients with prolonged and normal QTc (44% vs 42%, p = 0.546), but was significantly higher in patients with prolonged QRS interval than in those with normal QRS (59% vs 37%, p = 0.004). In Cox proportional hazards analysis, prolonged QRS interval was associated with a nearly twofold increase in mortality (HR 1.94, 95% CI 1.22 to 3.07; p = 0.005). This association persisted after adjustment for variables routinely available in the ED.

CONCLUSIONS

Prolonged QRS interval, but not prolonged QTc interval, is associated with increased long-term mortality in patients with ADHF.

Influence of water immersion, water gymnastics and swimming on cardiac output in patients with heart failure

BACKGROUND

Whole-body water immersion leads to a significant shift of blood from the periphery to the intrathoracic circulation, followed by an increase in central venous pressure and heart volume. In patients with severely reduced left ventricular function, this hydrostatically induced volume shift might overstrain the cardiovascular adaptive mechanisms and lead to cardiac decompensation.

AIM

To assess the haemodynamic response to water immersion, gymnastics and swimming in patients with chronic heart failure (CHF).

METHODS

10 patients with compensated CHF (62.9 (6.3) years, ejection fraction 31.5% (4.1%), peak oxygen consumption (Vo(2)) 19.4 (2.8) ml/kg/min), 10 patients with coronary artery disease (CAD) but preserved left ventricular function (57.2 (5.6) years, ejection fraction 63.9% (5.5%), peak Vo(2) 28 (6.3) ml/kg/min), and 10 healthy controls (32.8 (7.2) years, peak Vo(2) 45.6 (6) ml/kg/min) were examined. Haemodynamic response to thermoneutral (32 degrees C) water immersion and exercise was measured using a non-invasive foreign gas rebreathing method during stepwise water immersion, water gymnastics and swimming.

RESULTS

Water immersion up to the chest increased cardiac index by 19% in controls, by 21% in patients with CAD and by 16% in patients with CHF. Although some patients with CHF showed a decrease of stroke volume during immersion, all subjects were able to increase cardiac index (by 87% in healthy subjects, by 77% in patients with CAD and by 53% in patients with CHF). Vo(2) during swimming was 9.7 (3.3) ml/kg/min in patients with CHF, 12.4 (3.5) ml/kg/min in patients with CAD and 13.9 (4) ml/kg/min in controls.

CONCLUSIONS

Patients with severely reduced left ventricular function but stable clinical conditions and a minimal peak Vo(2) of at least 15 ml/kg/min during a symptom-limited exercise stress test tolerate water immersion and swimming in thermoneutral water well. Although cardiac index and Vo(2) are lower than in patients with CAD with preserved left ventricular function and controls, these patients are able to increase cardiac index adequately during water immersion and swimming.

Influence of the exercise protocol on peak VO2 in patients after heart transplantation

BACKGROUND

The protocol and the duration of an exercise test have considerable influence on peak oxygen consumption (VO2). On a bicycle ergometer, the use of a ramp protocol with a target exercise duration of 8 to 12 minutes is recommended to reliably measure maximal oxygen uptake. Because of cardiac denervation, heart transplant recipients have a delayed heart rate adaptation to exercise, and oxygen uptake kinetics are altered.

METHODS

We investigated whether the rate of workload increase during exercise testing would influence peak VO2 after heart transplantation. Two symptom-limited exercise tests, applying a ramp and a 3-minute step protocol were effectuated on a bicycle ergometer.

RESULTS

Seventeen patients (14 men, 3 women), mean age 58.4 +/- 12.7 years, at 64.5 +/- 26.7 months post-transplant participated in the study. No statistically significant differences between the 2 protocols were found regarding total exercise duration until exhaustion (8:42 +/- 2:09 vs 8:48 +/- 2:27 minutes, p = 0.705), maximal workload reached (117.9 +/- 42.6 vs 106.4 +/- 40.5 W; p = 0.055), peak heart rate (135.8 +/- 11.6 vs 131.2 +/- 14.8 beats/min.; p = 0.061), and peak VO2 (20.9 +/- 5.2 vs 20.5 +/- 5.9 ml/kg/min; p = 0.538).

CONCLUSIONS

Peak VO2 seems insensitive to a stepwise or ramping exercise protocol in heart transplant patients when the workload increments are chosen in a way that a total exercise time of 8 to 12 minutes is achieved. Both protocols can therefore be applied to evaluate peak VO2.

Safety and exercise tolerance of acute high altitude exposure (3454 m) among patients with coronary artery disease

OBJECTIVES

To assess the safety and cardiopulmonary adaptation to high altitude exposure among patients with coronary artery disease.

METHODS

22 patients (20 men and 2 women), mean age 57 (SD 7) years, underwent a maximal, symptom limited exercise stress test in Bern, Switzerland (540 m) and after a rapid ascent to the Jungfraujoch (3454 m). The study population comprised 15 patients after ST elevation myocardial infarction and 7 after a non-ST elevation myocardial infarction 12 (SD 4) months after the acute event. All patients were revascularised either by percutaneous coronary angioplasty (n = 15) or by coronary artery bypass surgery (n = 7). Ejection fraction was 60 (SD 8)%. beta blocking agents were withheld for five days before exercise testing.

RESULTS

At 3454 m, peak oxygen uptake decreased by 19% (p < 0.001), maximum work capacity by 15% (p < 0.001) and exercise time by 16% (p < 0.001); heart rate, ventilation and lactate were significantly higher at every level of exercise, except at maximum exertion. No ECG signs of myocardial ischaemia or significant arrhythmias were noted.

CONCLUSIONS

Although oxygen demand and lactate concentrations are higher during exercise at high altitude, a rapid ascent and submaximal exercise can be considered safe at an altitude of 3454 m for low risk patients six months after revascularisation for an acute coronary event and a normal exercise stress test at low altitude.

QR in V1--an ECG sign associated with right ventricular strain and adverse clinical outcome in pulmonary embolism

AIMS

To test the hypothesis that Qr in V(1)is a predictor of pulmonary embolism, right ventricular strain, and adverse clinical outcome.

METHODS AND RESULTS

ECG's from 151 patients with suspected pulmonary embolism were blindly interpreted by two observers. Echocardiography, troponin I, and pro-brain natriuretic peptide levels were obtained in 75 patients with pulmonary embolism. Qr in V(1)(14 vs 0 in controls; p<0.0001) and ST elevation in V(1)> or =1 mV (15 vs 1 in controls; p=0.0002) were more frequently present in patients with pulmonary embolism. Sensitivity and specificity of Qr in V(1)and T wave inversion in V(2)for predicting right ventricular dysfunction were 31/97% and 45/94%, respectively. Three of five patients who died in-hospital and 11 of 20 patients with a complicated course, presented with Qr in V(1). After adjustment for right ventricular strain including ECG, echocardiography, pro-brain natriuretic peptide and troponin I levels, Qr in V(1)(OR 8.7, 95%CI 1.4-56.7; p=0.02) remained an independent predictor of adverse outcome.

CONCLUSIONS

Among the ECG signs seen in patients with acute pulmonary embolism, Qr in V(1)is closely related to the presence of right ventricular dysfunction, and is an independent predictor of adverse clinical outcome.