OBJECTIVES: This study sought to define the invasive hemodynamic correlates of peak oxygen consumption (Vo2) in both supine and upright exercise in heart failure with preserved ejection fraction (HFpEF) and evaluate its diagnostic role as a method to discriminate HFpEF from noncardiac etiologies of dyspnea (NCD). BACKGROUND: Peak Vo2 is depressed in patients with HFpEF. The hemodynamic correlates of reduced peak Vo2 and its role in the clinical evaluation of HFpEF are unclear. METHODS: Consecutive patients with dyspnea and normal EF (N = 206) undergoing both noninvasive upright and invasive supine cardiopulmonary exercise testing were examined. Patients with invasively verified HFpEF were compared with those with NCD. RESULTS: Compared with NCD (n = 72), HFpEF patients (n = 134) displayed lower peak Vo2 during upright and supine exercise. Left heart filling pressures during exercise were inversely correlated with peak Vo2 in HFpEF, even after accounting for known determinants of O2 transport according to the Fick principle. Very low upright peak Vo2 (<14 ml/kg/min) discriminated HFpEF from NCD with excellent specificity (91%) but poor sensitivity (50%). Preserved peak Vo2 (>20 ml/kg/min) excluded HFpEF with high sensitivity (90%) but had poor specificity (49%). Intermediate peak Vo2 cutoff points were associated with substantial overlap between cases and NCD. CONCLUSIONS: Elevated cardiac filling pressure during exercise is independently correlated with reduced exercise capacity in HFpEF, irrespective of body position, emphasizing its importance as a novel therapeutic target. Noninvasive cardiopulmonary testing discriminates HFpEF and NCD at high and low values, but additional testing is required for patients with intermediate peak Vo2.

• Klíčová slova
• HFpEF, diagnosis, exercise, heart failure, hemodynamics,
• MeSH
• dospělí MeSH
• dyspnoe etiologie   MeSH
• hemodynamika MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• spotřeba kyslíku * MeSH
• srdeční katetrizace MeSH
• srdeční selhání komplikace   diagnóza   patofyziologie   MeSH
• studie případů a kontrol MeSH
• supinační poloha MeSH
• tepový objem * MeSH
• tlak MeSH
• tolerance zátěže MeSH
• zátěžový test metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: Cardiac reserve is depressed in patients with heart failure and preserved ejection fraction (HFpEF). The mechanisms causing this are poorly understood. OBJECTIVES: The authors hypothesized that myocardial injury might contribute to the hemodynamic derangements and cardiac reserve limitations that are present in HFpEF. Markers of cardiomyocyte injury, central hemodynamics, ventricular function, and determinants of cardiac oxygen supply-demand balance were measured. METHODS: Subjects with HFpEF (n = 38) and control subjects without heart failure (n = 20) underwent cardiac catheterization, echocardiography, and expired gas analysis at rest and during exercise. Central venous blood was sampled to measure plasma high-sensitivity troponin T levels as an index of cardiomyocyte injury. RESULTS: Compared with control subjects, troponins were more than 2-fold higher in subjects with HFpEF at rest and during exercise (p < 0.0001). Troponin levels were directly correlated with left ventricular (LV) filling pressures (r = 0.52; p < 0.0001) and diastolic dysfunction (r = -0.43; p = 0.002). Although myocardial oxygen demand was similar, myocardial oxygen supply was depressed in HFpEF, particularly during exercise (coronary perfusion pressure-time integral; 44 ± 9 mm Hg × s × min-1 × l × dl-1 vs. 30 ± 9 mm Hg × s × min-1 × l × dl-1; p < 0.0001), and reduced indices of supply were correlated with greater myocyte injury during exercise (r = -0.44; p = 0.0008). Elevation in troponin with exercise was directly correlated with an inability to augment LV diastolic (r = -0.40; p = 0.02) and systolic reserve (r = -0.57; p = 0.0003), greater increases in LV filling pressures (r = 0.55; p < 0.0001), blunted cardiac output response (r = -0.44; p = 0.002), and more severely depressed aerobic capacity in HFpEF. CONCLUSIONS: Limitations in LV functional reserve and the hemodynamic derangements that develop secondary to these limitations during exercise in HFpEF are correlated with the severity of cardiac injury, assessed by plasma levels of troponin T. Further study is warranted to determine the mechanisms causing myocyte injury in HFpEF and the potential role of ischemia, and to identify and test novel interventions targeted to these mechanisms. (EXEC [Study of Exercise and Heart Function in Patients With Heart Failure and Pulmonary Vascular Disease]; NCT01418248).

• Klíčová slova
• HFpEF, biomarkers, exercise, heart failure, hemodynamics, troponin T,
• MeSH
• cvičení fyziologie   MeSH
• kyslík krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nemoci koronárních tepen patofyziologie   MeSH
• poranění srdce krev   etiologie   patofyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční selhání krev   komplikace   patofyziologie   MeSH
• studie případů a kontrol MeSH
• tepový objem MeSH
• troponin T krev   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• kyslík MeSH
• troponin T MeSH

BACKGROUND: Diagnosis of heart failure with preserved ejection fraction (HFpEF) is challenging and relies largely on demonstration of elevated cardiac filling pressures (pulmonary capillary wedge pressure). Current guidelines recommend use of natriuretic peptides (N-terminal pro-B type natriuretic peptide) and rest/exercise echocardiography (E/e' ratio) to make this determination. Data to support this practice are conflicting. METHODS: Simultaneous echocardiographic-catheterization studies were prospectively conducted at rest and during exercise in subjects with invasively proven HFpEF (n=50) and participants with dyspnea but no identifiable cardiac pathology (n=24). RESULTS: N-Terminal pro-B type natriuretic peptide levels were below the level considered to exclude disease (≤125 pg/mL) in 18% of subjects with HFpEF. E/e' ratio was correlated with directly measured pulmonary capillary wedge pressure at rest (r=0.63, P<0.0001) and during exercise (r=0.57, P<0.0001). Although specific, current guidelines were poorly sensitive, identifying only 34% to 60% of subjects with invasively proven HFpEF on the basis of resting echocardiographic data alone. Addition of exercise echocardiographic data (E/e' ratio>14) improved sensitivity (to 90%) and thus negative predictive value, but decreased specificity (71%). CONCLUSIONS: Currently proposed HFpEF diagnostic guidelines on the basis of resting data are poorly sensitive. Adding exercise E/e' data improves sensitivity and negative predictive value but compromises specificity, suggesting that exercise echocardiography may help rule out HFpEF. These results question the accuracy of current approaches to exclude HFpEF on the basis of resting data alone and reinforce the value of exercise testing using invasive and noninvasive hemodynamic assessments to definitively confirm or refute the diagnosis of HFpEF. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01418248.

• Klíčová slova
• diagnosis, exercise, exercise test, heart failure,
• MeSH
• echokardiografie MeSH
• funkce levé komory srdeční fyziologie   MeSH
• hemodynamika MeSH
• lidé středního věku MeSH
• lidé MeSH
• natriuretický peptid typu B analýza   MeSH
• peptidové fragmenty analýza   MeSH
• prospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční selhání diagnóza   diagnostické zobrazování   MeSH
• tepový objem fyziologie   MeSH
• zátěžový test MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• natriuretický peptid typu B MeSH
• peptidové fragmenty MeSH
• pro-brain natriuretic peptide (1-76) MeSH Prohlížeč