Hemodynamic Cardiac Stress Research Articles

Quantifying Hemodynamic Cardiac Stress and Cardiomyocyte Injury in Normotensive and Hypertensive Acute Heart Failure.

The characterization of the different pathophysiological mechanisms involved in normotensive versus hypertensive acute heart failure (AHF) might help to develop individualized treatments. The extent of hemodynamic cardiac stress and cardiomyocyte injury was quantified by measuring the B-type natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP), and high-sensitivity cardiac troponin T (hs-cTnT) concentrations in 1152 patients presenting with centrally adjudicated AHF to the emergency department (ED) (derivation cohort). AHF was classified as normotensive with a systolic blood pressure (SBP) of 90-140 mmHg and hypertensive with SBP > 140 mmHg at presentation to the ED. Findings were externally validated in an independent AHF cohort (n = 324). In the derivation cohort, with a median age of 79 years, 43% being women, 667 (58%) patients had normotensive and 485 (42%) patients hypertensive AHF. Hemodynamic cardiac stress, as quantified by the BNP and NT-proBNP, was significantly higher in normotensive as compared to hypertensive AHF [1105 (611-1956) versus 827 (448-1419) pg/mL, and 5890 (2959-12,162) versus 4068 (1986-8118) pg/mL, both p < 0.001, respectively]. Similarly, the extent of cardiomyocyte injury, as quantified by hs-cTnT, was significantly higher in normotensive AHF as compared to hypertensive AHF [41 (24-71) versus 33 (19-59) ng/L, p < 0.001]. A total of 313 (28%) patients died during 360 days of follow-up. All-cause mortality was higher in patients with normotensive AHF vs. patients with hypertensive AHF (hazard ratio 1.66, 95%CI 1.31-2.10; p < 0.001). Normotensive patients with a high BNP, NT-proBNP, or hs-cTnT had the highest mortality. The findings were confirmed in the validation cohort. Biomarker profiling revealed a higher extent of hemodynamic stress and cardiomyocyte injury in patients with normotensive versus hypertensive AHF.

Cardiovascular biomarkers in patients with COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has increased awareness that severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2) may have profound effects on the cardiovascular system. COVID-19 often affects patients with pre-existing cardiac disease, and may trigger acute respiratory distress syndrome (ARDS), venous thromboembolism (VTE), acute myocardial infarction (AMI), and acute heart failure (AHF). However, as COVID-19 is primarily a respiratory infectious disease, there remain substantial uncertainty and controversy whether and how cardiovascular biomarkers should be used in patients with suspected COVID-19. To help clinicians understand the possible value as well as the most appropriate interpretation of cardiovascular biomarkers in COVID-19, it is important to highlight that recent findings regarding the prognostic role of cardiovascular biomarkers in patients hospitalized with COVID-19 are similar to those obtained in studies for pneumonia and ARDS in general. Cardiovascular biomarkers reflecting pathophysiological processes involved in COVID-19/pneumonia and its complications have a role evaluating disease severity, cardiac involvement, and risk of death in COVID-19 as well as in pneumonias caused by other pathogens. First, cardiomyocyte injury, as quantified by cardiac troponin concentrations, and haemodynamic cardiac stress, as quantified by natriuretic peptide concentrations, may occur in COVID-19 as in other pneumonias. The level of those biomarkers correlates with disease severity and mortality. Interpretation of cardiac troponin and natriuretic peptide concentrations as quantitative variables may aid in risk stratification in COVID-19/pneumonia and also will ensure that these biomarkers maintain high diagnostic accuracy for AMI and AHF. Second, activated coagulation as quantified by D-dimers seems more prominent in COVID-19 as in other pneumonias. Due to the central role of endothelitis and VTE in COVID-19, serial measurements of D-dimers may help physicians in the selection of patients for VTE imaging and the intensification of the level of anticoagulation from prophylactic to slightly higher or even therapeutic doses.

P3532Quantifying hemodynamic cardiac stress and cardiomyocyte injury in hypertensive and normotensive acute heart failure

Abstract Background Better characterization of the different pathophysiological mechanisms involved in normotensive and hypertensive acute heart failure (AHF) might help to develop novel individualized treatment strategies. Methods The extent of hemodynamic cardiac stress and cardiomyocyte injury was quantified by measuring B-type natriuretic peptide (BNP) as well as high-sensitive cardiac troponin T (hs-cTnT) in 1,152 unselected patients presenting with AHF to the emergency department (derivation cohort). Systolic blood pressure (SBP) of 90 - 140 mmHg at presentation was used to define normotensive AHF. Findings regarding hemodynamic cardiac stress and cardiomyocyte injury were validated in a second independent AHF cohort (validation cohort; n=324). Results In the derivation cohort 667 (58%) patients had hypertensive AHF. Hemodynamic cardiac stress, as quantified by BNP levels, was significantly higher in normotensive AHF as compared to hypertensive AHF (1,105 pg/mL versus 827 pg/mL, p&lt;0.001). In addition, the extent of cardiomyocyte injury, as quantified by hs-cTnT, was significantly higher in normotensive AHF as compared to hypertensive AHF (41 ng/L versus 33 ng/L, p&lt;0.001). These findings were confirmed in the validation cohort. Table 1. Cardiac stress and myocardial necrosis as quantified by BNP and hs-cTnT plasma concentrations Overall Hypertensive AHF Normotensive AHF p-value BNP in pg/ml, median (IQR) 974 (536–1,712) 827 (448–1,419) 1,105 (611–1,956) &lt;0.001 hs-cTnT in ng/L, median (IQR) 37 (22–67) 33 (19–59) 41 (24–71) &lt;0.001 BNP = B-type natriuretic peptide; hs-cTnT = high-sensitivity cardiac Troponin T; IQR = inter-quartile range. Figure 1 Conclusion Biomarker profiling revealed that the extent of hemodynamic stress and cardiomyocyte injury is different in patients with normotensive and hypertensive AHF. This characterization could help to understand AHF phenotypes better, which in turn may lead to more specific management in future, thus improving the dismal prognosis in these patients. Acknowledgement/Funding European Union, Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, University of Basel

Assessment of Pulmonary Congestion During Cardiac Hemodynamic Stress Testing

Assessment of Pulmonary Congestion During Cardiac Hemodynamic Stress Testing

Monitoring Cell-Type-Specific Gene Expression Using Ribosome Profiling In Vivo During Cardiac Hemodynamic Stress.

Gene expression profiles have been mainly determined by analysis of transcript abundance. However, these analyses cannot capture posttranscriptional gene expression control at the level of translation, which is a key step in the regulation of gene expression, as evidenced by the fact that transcript levels often poorly correlate with protein levels. Furthermore, genome-wide transcript profiling of distinct cell types is challenging due to the fact that lysates from tissues always represent a mixture of cells. This study aimed to develop a new experimental method that overcomes both limitations and to apply this method to perform a genome-wide analysis of gene expression on the translational level in response to pressure overload. By combining ribosome profiling (Ribo-seq) with a ribosome-tagging approach (Ribo-tag), it was possible to determine the translated transcriptome in specific cell types from the heart. After pressure overload, we monitored the cardiac myocyte translatome by purifying tagged cardiac myocyte ribosomes from cardiac lysates and subjecting the ribosome-protected mRNA fragments to deep sequencing. We identified subsets of mRNAs that are regulated at the translational level and found that translational control determines early changes in gene expression in response to cardiac stress in cardiac myocytes. Translationally controlled transcripts are associated with specific biological processes related to translation, protein quality control, and metabolism. Mechanistically, Ribo-seq allowed for the identification of upstream open reading frames in transcripts, which we predict to be important regulators of translation. This method has the potential to (1) provide a new tool for studying cell-specific gene expression at the level of translation in tissues, (2) reveal new therapeutic targets to prevent cellular remodeling, and (3) trigger follow-up studies that address both, the molecular mechanisms involved in the posttranscriptional control of gene expression in cardiac cells, and the protective functions of proteins expressed in response to cellular stress.

Heart Failure Association of the European Society of Cardiology practical guidance on the use of natriuretic peptide concentrations.

Natriuretic peptide [NP; B-type NP (BNP), N-terminal proBNP (NT-proBNP), and midregional proANP (MR-proANP)] concentrations are quantitative plasma biomarkers for the presence and severity of haemodynamic cardiac stress and heart failure (HF). End-diastolic wall stress, intracardiac filling pressures, and intracardiac volumes seem to be the dominant triggers. This paper details the most important indications for NPs and highlights 11 key principles underlying their clinical use shown below. NPs should always be used in conjunction with all other clinical information. NPs are reasonable surrogates for intracardiac volumes and filling pressures. NPs should be measured in all patients presenting with symptoms suggestive of HF such as dyspnoea and/or fatigue, as their use facilitates the early diagnosis and risk stratification of HF. NPs have very high diagnostic accuracy in discriminating HF from other causes of dyspnoea: the higher the NP, the higher the likelihood that dyspnoea is caused by HF. Optimal NP cut-off concentrations for the diagnosis of acute HF (very high filling pressures) in patients presenting to the emergency department with acute dyspnoea are higher compared with those used in the diagnosis of chronic HF in patients with dyspnoea on exertion (mild increase in filling pressures at rest). Obese patients have lower NP concentrations, mandating the use of lower cut-off concentrations (about 50% lower). In stable HF patients, but also in patients with other cardiac disorders such as myocardial infarction, valvular heart disease, atrial fibrillation or pulmonary embolism, NP concentrations have high prognostic accuracy for death and HF hospitalization. Screening with NPs for the early detection of relevant cardiac disease including left ventricular systolic dysfunction in patients with cardiovascular risk factors may help to identify patients at increased risk, therefore allowing targeted preventive measures to prevent HF. BNP, NT-proBNP and MR-proANP have comparable diagnostic and prognostic accuracy. In patients with shock, NPs cannot be used to identify cause (e.g. cardiogenic vs. septic shock), but remain prognostic. NPs cannot identify the underlying cause of HF and, therefore, if elevated, must always be used in conjunction with cardiac imaging.

Prevalence and determinants of exercise-induced left ventricular dysfunction in patients with coronary artery disease.

The phenomenon of exercise-induced left ventricular dysfunction (LVD) is incompletely understood. Better understanding of its prevalence and determinants might help to address the current potential oversimplification of the relation between physical activity and cardiac health in patients with coronary artery disease (CAD). We prospectively assessed the prevalence and determinants of exercise-induced LVD in patients with stable CAD and normal LV function at rest undergoing bicycle rest/stress myocardial perfusion imaging single-photon emission computed tomography (MPI-SPECT). Exercise-induced LVD was defined as a relevant (5% or more) drop in left ventricular ejection fraction after maximal exercise. High-sensitivity cardiac troponin I/T (Hs-cTnI/T) and N-terminal probrain natriuretic peptide (NT-proBNP) concentrations were measured before exercise to quantify cardiomyocyte injury and hemodynamic cardiac stress, respectively. Among 317 patients, exercise-induced LVD was present in 83 (26%) patients. Exercise-induced LVD was associated with the extent of exercise-inducible myocardial ischaemia as well as transient ischaemic dilatation. Still, 43% of patients developing exercise-induced LVD did not have functionally relevant CAD. Neither baseline characteristics, nor the quantification of the extent of cardiomyocyte injury and hemodynamic cardiac stress using hs-cTnI/T and NT-proBNP concentrations, respectively, allowed predicting exercise-induced LVD. One out of four patients with stable CAD develops exercise-induced LVD after bicycle exercise test. While the extent of exercise-inducible myocardial ischaemia is a predictor, other still unrecognized mechanisms also seem to play a major role, as nearly half of all patients with exercise-induced LVD do not have functionally relevant CAD.

Relative hypochromia and mortality in acute heart failure

BackgroundRelative hypochromia of erythrocytes defined as a reduced mean corpuscular hemoglobin concentration (MCHC) is a surrogate of iron deficiency. We aimed to evaluate the prevalence and prognostic impact of relative hypochromia in acute heart failure (AHF). MethodsWe prospectively characterized 1574 patients presenting with an adjudicated diagnosis of AHF to the emergency department. Relative hypochromia was defined as a MCHC ≤330 g/l and determined at presentation. The presence of AHF was adjudicated by two independent cardiologists. All-cause mortality and AHF-rehospitalization were the primary prognostic end-points. ResultsOverall, 455 (29%) AHF patients had relative hypochromia. Patients with relative hypochromia had higher hemodynamic cardiac stress as quantified by NT-proBNP concentrations (p < 0.001), more extensive cardiomyocyte injury as quantified by high-sensitive cardiac troponin T (hs-cTnT) concentrations (p < 0.001), and lower estimated glomerular filtration rate (eGFR; p < 0.001) as compared to AHF patients without hypochromia. Cumulative incidences for all-cause mortality and AHF-rehospitalization at 720-days were 50% and 55% in patients with relative hypochromia as compared to 33% and 39% in patients without hypochromia, respectively (both p < 0.0001). The association between relative hypochromia and increased mortality (HR 1.7, 95% CI 1.4–2-0) persisted after adjusting for anemia (HR 1.5, 95% CI 1.3–1.8), and after adjusting for hemodynamic cardiac stress (HR 1.46, 95% CI 1.21–1.76) and eGFR (HR 1.5, 95% CI 1.3–1.8, p < 0.001). ConclusionsRelative hypochromia is common and a strong and independent predictor of increased mortality in AHF. Given the direct link to diagnostic (endoscopy) and therapeutic interventions to treat functional iron deficiency, relative hypochromia deserves increased attention as an inexpensive and universally available biomarker.

Multimarker assessment for the prediction of renal function improvement after percutaneous revascularization for renal artery stenosis.

Identifying patients likely to have improved renal function after percutaneous transluminal renal angioplasty and stenting (PTRA) for renal artery stenosis (RAS) is challenging. The purpose of this study was to use a comprehensive multimarker assessment to identify those patients who would benefit most from correction of RAS. In 127 patients with RAS and decreased renal function and/or hypertension referred for PTRA, quantification of hemodynamic cardiac stress using B-type natriuretic peptide (BNP), renal function using estimated glomerular filtration rate (eGFR), parenchymal renal damage using resistance index (RI), and systemic inflammation using C-reactive protein (CRP) were performed before intervention. Predefined renal function improvement (increase in eGFR ≥10%) at 6 months occurred in 37% of patients. Prognostic accuracy as quantified by the area under the receiver-operating characteristics curve for the ability of BNP, eGFR, RI and CRP to predict renal function improvement were 0.59 (95% CI, 0.48-0.70), 0.71 (95% CI, 0.61-0.81), 0.52 (95% CI, 0.41-0.65), and 0.56 (95% CI, 0.44-0.68), respectively. None of the possible combinations increased the accuracy provided by eGFR (lower eGFR indicated a higher likelihood for eGFR improvement after PTRA, P=ns for all). In the subgroup of 56 patients with pre-interventional eGFR <60 mL/min/1.73 m(2), similar findings were obtained. Quantification of renal function, but not any other pathophysiologic signal, provides at least moderate accuracy in the identification of patients with RAS in whom PTRA will improve renal function.

Cardiomyocyte injury induced by hemodynamic cardiac stress: Differential release of cardiac biomarkers

ObjectiveWe explored whether hemodynamic cardiac stress leads to a differential release of cardiomyocyte injury biomarkers, used in the diagnosis of acute myocardial infarction (AMI). MethodsIn an observational international multicenter study, we enrolled 831 unselected patients presenting with symptoms suggestive of AMI to the emergency department. The final diagnosis was adjudicated by two independent cardiologists. Hemodynamic cardiac stress was quantified by levels of B-type natriuretic peptide (BNP). Spearman's rho correlation was used to analyze the correlations between BNP and high-sensitivity cardiac troponin T (hs-cTnT), Siemens cTnI-Ultra (cTnI-ultra), CK-MB and Myoglobin. Patients were categorized according to the extent of hemodynamic cardiac stress as quantified by BNP tertiles. ResultsAmong all patients, the positive pair-wise correlation with BNP was strongest with hs-cTnT and cTnI-ultra (r=0.58 and 0.50, respectively), moderate for Myoglobin (r=0.43), and weakest with CK-MB (r=0.25; p<0.001 for each). Similar pattern of correlations was also observed among AMI patients. Among patients diagnosed with non-cardiac cause of chest pain (n=385, 46%) and cardiac but non-coronary (n=109, 13%), BNP had significant positive correlations with hs-cTnT, cTnI-ultra and Myoglobin (p<0.05), but not with CK-MB (p=NS). A similar pattern of stronger correlation between BNP and hs-cTnT, cTnI-ultra and Myoglobin as compared to that with CK-MB was also observed within the higher BNP tertile range. There was no correlation between BNP and other biomarkers within the 1st BNP tertile group. ConclusionHemodynamic cardiac stress, as quantified by BNP, as a likely cause of cardiomyocyte injury, is more closely reflected by concentrations of hs-cTnT, cTnI-ultra and Myoglobin than CK-MB.

Control of histone H3 phosphorylation by CaMKIIδ in response to haemodynamic cardiac stress.

Heart failure is associated with the reactivation of a fetal cardiac gene programme that has become a hallmark of cardiac hypertrophy and maladaptive ventricular remodelling, yet the mechanisms that regulate this transcriptional reprogramming are not fully understood. Using mice with genetic ablation of calcium/calmodulin-dependent protein kinase II δ (CaMKIIδ), which are resistant to pathological cardiac stress, we show that CaMKIIδ regulates the phosphorylation of histone H3 at serine-10 during pressure overload hypertrophy. H3 S10 phosphorylation is strongly increased in the adult mouse heart in the early phase of cardiac hypertrophy and remains detectable during cardiac decompensation. This response correlates with up-regulation of CaMKIIδ and increased expression of transcriptional drivers of pathological cardiac hypertrophy and of fetal cardiac genes. Similar changes are detected in patients with end-stage heart failure, where CaMKIIδ specifically interacts with phospho-H3. Robust H3 phosphorylation is detected in both adult ventricular myocytes and in non-cardiac cells in the stressed myocardium, and these signals are abolished in CaMKIIδ-deficient mice after pressure overload. Mechanistically, fetal cardiac genes are activated by increased recruitment of CaMKIIδ and enhanced H3 phosphorylation at hypertrophic promoter regions, both in mice and in human failing hearts, and this response is blunted in CaMKIIδ-deficient mice under stress. We also document that the chaperone protein 14–3–3 binds phosphorylated H3 in response to stress, allowing proper elongation of fetal cardiac genes by RNA polymerase II (RNAPII), as well as elongation of transcription factors regulating cardiac hypertrophy. These processes are impaired in CaMKIIδ-KO mice after pathological stress. The findings reveal a novel in vivo function of CaMKIIδ in regulating H3 phosphorylation and suggest a novel epigenetic mechanism by which CaMKIIδ controls cardiac hypertrophy. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Comprehensive biomarker profiling in patients with obstructive sleep apnea

ObjectivesThe pathophysiological links between obstructive sleep apnea syndrome (OSAS) and cardiovascular mortality are incompletely understood. We aimed to contribute to a better characterization by using comprehensive biomarker profiling quantifying hemodynamic cardiac stress, cardiomyocyte injury, inflammation, endothelial function, matrix turnover and metabolism. Design and methodsIn 65 patients with moderate or severe OSAS [apnea–hypopnea index (AHI) 39±20/h] and 33 patients with no or mild OSAS (AHI 8+4/h), B-type natriuretic peptide (BNP), N-terminal-pro-BNP (NT-proBNP), high-sensitivity cardiac troponin I (hs-cTnI), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and insulin were measured before and after sleep. In a subgroup measurements were repeated in a second night with continuous positive airway pressure (CPAP). ResultsPatients with moderate/severe OSAS had higher insulin before sleep [median (interquartile range), 36.4 (21.9–52.1) vs. 20.8 (10.6–32.8)mU/mL; p=0.006], higher IL-6 after sleep [1.00 (0.73–1.58) vs. 0.72 (0.48–0.94)pg/mL; p=0.005], and larger relative overnight reduction in BNP [−9 (−35–0) vs. −3 (−21–13)%; p=0.04] than those with mild/no OSAS. Insulin before sleep was the only independent predictor of moderate/severe OSAS. Insulin before and IL-6 after sleep were independent predictors of severe OSAS, and when combined provided high diagnostic accuracy for severe OSAS (area under the receiver operator characteristic curve 0.80; 95%-confidence interval 0.69–0.91). In contrast, there were no significant differences in NT-proBNP, hs-cTnI, VEGF, and MMP-9 between moderate/severe and mild/no OSAS. Short-term CPAP had no impact on biomarker concentrations before and after sleep. ConclusionsSignificant OSAS is characterized by a distinct biomarker profile including high insulin before and high IL-6 after sleep.

Longitudinal changes in late systolic cardiac load and serum NT-proBNP levels in healthy middle-aged Japanese men.

We determined whether any significant association exists between change in late systolic cardiac load with time, estimated by radial pressure waveform analysis, and development of cardiac hemodynamic stress in individuals with preserved cardiac function. Brachial-ankle pulse wave velocity, radial augmentation index (rAI), first peak of the radial pressure waveform (SP1), systolic and pulse pressure at the second peak of the radial pressure waveform (SP2 and PP2), and serum levels of N-terminal fragment B-type natriuretic peptide (NT-proBNP) were measured at the start (first examination) and at the end (second examination) of this 3-year study in healthy Japanese men (n = 1,851). A stepwise multivariate linear regression analysis demonstrated that among the parameters of radial pressure waveform analysis and markers of arterial stiffness analyzed, only PP2 was significantly associated with serum NT-proBNP levels in study participants at both the first and second examinations. Furthermore, among the parameters analyzed, only change in PP2 was significantly correlated with the change in serum NT-proBNP levels during the study period (beta = 0.131, P < 0.001). Sustained late systolic cardiac load might be a more significant determinant of the development of cardiac hemodynamic stress than sustained early systolic cardiac load or arterial stiffening in individuals with preserved cardiac function.

HEMODYNAMIC CARDIAC STRESS INDUCED MYOCARDIAL ISCHEMIA AS DETECTED BY THE RELEASE OF CARDIAC BIOMARKERS: CARDIAC TROPONIN T AND I, CK-MB AND MYOGLOBIN

It is unknown whether hemodynamic cardiac stress leads to a differential release of the markers of cardiomyocyte injury commonly used in the diagnosis of acute myocardial infarction In an observational international multicenter study, we enrolled 831 unselected acute chest pain patients presenting

Early Change of Extracellular Matrix and Diastolic Parameters in Metabolic Syndrome

BackgroundMetabolic syndrome (MS) is associated with increased cardiovascular risk. It is not clear whether myocardial changes showed in this syndrome, such as diastolic dysfunction, are due to the systemic effects of the syndrome, or to specific myocardial effects. ObjectivesCompare diastolic function, biomarkers representing extracellular matrix activity (ECM), inflammation and cardiac hemodynamic stress in patients with the MS and healthy controls. MethodsMS patients (n = 76) and healthy controls (n=30) were submitted to a clinical assessment, echocardiographic study, and measurement of plasma levels of metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), ultrasensitive-reactive-C-Protein (us-CRP), insulin resistance (HOMA-IR) and natriuretic peptide (NT-proBNP). ResultsMS group showed lower E' wave (10.1 ± 3.0 cm/s vs 11.9 ± 2.6 cm/s, p = 0.005), increased A wave (63.4 ± 14.1 cm/s vs. 53.1 ± 8.9 cm/s; p < 0.001), E/E' ratio (8.0 ± 2.2 vs. 6.3 ± 1.2; p < 0.001), MMP9 (502.9 ± 237.1 ng / mL vs. 330.4±162.7 ng/mL; p < 0.001), us-CRP (p = 0.001) and HOMA-IR (p < 0.001), but no difference for TIMP1 or NT-proBNP levels. In a multivariable analysis, only MMP9 was independently associated with MS. ConclusionMS patients showed differences for echocardiographic measures of diastolic function, ECM activity, us-CRP and HOMA-IR when compared to controls. However, only MMP9 was independently associated with the MS. These findings suggest that there are early effects on ECM activity, which cannot be tracked by routine echocardiographic measures of diastolic function.

Pathophysiology of Lower Extremity Edema in Acute Heart Failure Revisited

BackgroundThe pathophysiology and key determinants of lower extremity edema in patients with acute heart failure are poorly investigated. MethodsWe prospectively enrolled 279 unselected patients presenting to the Emergency Department with acute heart failure. Lower extremity edema was quantified at predefined locations. Left ventricular ejection fraction, central venous pressure quantifying right ventricular failure, biomarkers to quantify hemodynamic cardiac stress (B-type natriuretic peptide), and the activity of the arginine-vasopressin system (copeptin) also were recorded. ResultsLower extremity edema was present in 218 (78%) patients and limited to the ankle in 22%, reaching the lower leg in 40%, reaching the upper leg in 11%, and was generalized (anasarca) in 3% of patients. Patients in the 4 strata according to the presence and extent of lower leg edema had comparable systolic blood pressure, left ventricular ejection fraction, central venous pressure, and B-type natriuretic peptide levels, as well as copeptin and glomerular filtration rate (P=NS for all). The duration of dyspnea preceding the presentation was longer in patients with more extensive edema (P=.006), while serum sodium (P=.02) and serum albumin (P=.03) was lower. ConclusionCentral venous pressure, hemodynamic cardiac stress, left ventricular ejection fraction, and the activity of the arginine-vasopressin system do not seem to be key determinants of the presence or extent of lower extremity edema in acute heart failure.

The effects of running a 308 km ultra-marathon on cardiac markers

The aim of this study was to investigate the expression of cardiac strain and damage in 18 male marathoners with average age of 52.8±5.0 years running at a 308 km ultra-marathon. Blood samples were collected at pre-race, 100 km, 200 km and 308 km check points for the analysis of cardiac muscle injury markers, creatine kinase (CK), creatine kinase–myocardial band (CK–MB), cardiac troponin I (cTnI) and cardiac muscle strain marker, N-terminal pro-brain natriuretic peptide (NT-proBNP). The CK levels increased 1127.2±507.9 IU/L, 5133.8±2492.7 IU/L and 4958.4±2087.9 IU/L at 100 km, 200 km and 308 km, respectively, compared to the pre-race levels. The CK–MB levels increased 20.2±11.2 ng/mL, 73.3±35.6 ng/mL and 68.6±42.6 ng/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The CK–MB/CK ratio showed that the CK–MB mass index was within the normal range (<2.5%) at 100 km, 200 km and 308 km. The cTnI levels showed no significant difference in all check points. The NT-proBNP levels increased 146.55±92.7 pg/mL, 167.95±111.9 pg/mL and 241.23±121.2 pg/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The normal CK–MB mass index (<5.0 ng/mL) and the absence of an increase in the cTnI levels during the 308 km ultra-marathon suggested that no myocardial injury despite an elevation in CK–MB. The increase in NT-proBNP levels probably resulted from continuous hemodynamic cardiac stress and represents a transient physiological myocardial protective response.

Plasma Biomarkers for Prediction of Sudden Cardiac Death

Sudden cardiac death (SCD) accounts for most cardiovascular deaths in the United States, claiming an estimated 300 000 lives per year.1 Despite intense efforts to develop resuscitation techniques, survival rates are still low, at ≈5%.2 This has led to a renewed focus in this field directed toward optimizing risk prediction to identify the candidate that would qualify for prophylactic or preventive interventions.3 At present, the clinical risk stratification is largely limited to the use of left ventricular ejection fraction (LVEF) for identifying primary prophylaxis candidates, but specificity of this predictor is modest.4 Moreover, the absolute numbers of these high-risk patients in the general population are low. Instead, the highest prevalence of SCD is likely observed among previously asymptomatic individuals, even though it is well-known that coronary artery disease (CAD) is present in most SCD cases.5 This underscores the need for the development of risk stratification models that can be applied to the general population where the largest health benefit is likely to be realized. The underpinnings of SCD are complex, and it is reasonable to believe that the risk stratification instrument of the future is likely to involve other components beyond clinical risk markers. Novel genomic variants show promise but are still in early phases of development as risk stratification targets. However, the “unbiased” approaches made possible through genomewide association studies have led to the recent identification of specific genetic variants that could predict SCD.6,7 This has reignited the interest in plasma biomarkers as a means for risk stratification. This article will review the emerging evidence and role of plasma biomarkers in predicting SCD in the general population and suggest a blueprint for future studies of potential utility. ### Uniform Definition of SCD Given the complexity and dynamic nature of the condition, there has been some variability …

Quantifying Cardiac Hemodynamic Stress and Cardiomyocyte Damage in Ischemic and Nonischemic Acute Heart Failure

The early and noninvasive differentiation of ischemic and nonischemic acute heart failure (AHF) in the emergency department (ED) is an unmet clinical need. We quantified cardiac hemodynamic stress using B-type natriuretic peptide (BNP) and cardiomyocyte damage using 2 different cardiac troponin assays in 718 consecutive patients presenting to the ED with AHF (derivation cohort). The diagnosis of ischemic AHF was adjudicated using all information, including coronary angiography. Findings were validated in a second independent multicenter cohort (326 AHF patients). Among the 718 patients, 400 (56%) were adjudicated to have ischemic AHF. BNP levels were significantly higher in ischemic compared with nonischemic AHF (1097 [604-1525] pg/mL versus 800 [427-1317] pg/mL; P<0.001). Cardiac troponin T (cTnT) and sensitive cardiac troponin I (s-cTnI) were also significantly higher in ischemic compared with nonischemic AHF patients (0.040 [0.010-0.306] μg/L versus 0.018 [0.010-0.060] μg/L [P<0.001]; 0.024 [0.008-0.106] μg/L versus 0.016 [0.004-0.044 ] μg/L [P=0.002]). The diagnostic accuracy of BNP, cTnT, and s-cTnI for the diagnosis of ischemic AHF, as quantified by the area under the receiver-operating characteristic curve, was low (0.58 [95% CI, 0.54-0.63], 0.61 [95% CI, 0.57-0.66], and 0.59 [95% CI,0.54-0.65], respectively). These findings were confirmed in the validation cohort. At presentation to the ED, patients with ischemic AHF exhibit more extensive hemodynamic cardiac stress and cardiomyocyte damage than patients with nonischemic AHF. However, the overlap is substantial, resulting in poor diagnostic accuracy.

Utile or futile: biomarkers in the ICU

Biomarkers complement other clinical information by proving quantitative data regarding a pathophysiological mechanism that can be used for the early diagnosis of a specific disease, to monitor and guide treatment, and to predict the risk of death or other adverse events. The stronger the link between the information provided by the biomarker and the immediate clinical course of action that we physicians take in response, the higher the clinical utility of the biomarker. This link is weakest for prognostic biomarkers applied in patients with a wide variety of diseases, such as in unselected intensive care unit (ICU) patients. Although the added value on top of current ICU mortality scores seems to be too low to justify clinical use, the observation that hemodynamic cardiac stress and inflammation are present in multiple conditions provides important insights into the pathophysiology of common disorders in the ICU.