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Noninvasive Impedance Cardiography Measurements Increase the Diagnostic Ability of B-Type Natriuretic Peptide for Diastolic Heart Failure
S36 Journal of Cardiac Failure Vol. 12 No. 6 Suppl. 2006 115 Extremely High BNP Does Not Reflect the Severity of Heart Failure Rayan Hourani, Shridavi Pitta, Maya Guglin; Medicine, Wayne State University, Detroit, MI Background: BNP is elevated in HF and reflects its severity, but it is not known why some patients have extremely high BNP. Hypothesis: Extremely high BNP does not reflect the severity of HF. Methods: We retrospectively reviewed data on179 consecutive HF patients whose BNP on admission fell within one of three predetermined ranges: mild elevation: 500-1000pcg/mL (82 patients), moderate: 2000-3000 (48), and high: 4000 e 20000 (49). Results: More patients in the moderate group were on intravenous furosemide and on ACE inhibitors comparing to the mild group (87% vs 44.3%, p!0.01, and 78.3% vs 50.8%, p!0.05). In the high group, fewer patients were on ACE-inhibitors; other drugs did not differ. The left ventricular (LV) mass index, left atrial size, severity of mitral and tricuspid regurgitation, and E/E0 ratio (surrogate wedge) was higher, and ejection fraction and time velocity integral of LV outflow tract (surrogate cardiac output) was lower in patients with moderately elevated BNP comparing to mildly elevated BNP. These parameters did not differ between groups with moderately elevated and extremely high BNP. Conclusion: The difference in clinical, structural and hemodynamic parameters was found between groups with mildly and moderately elevated BNP. Extremely high BNP (4000-20000 pcg/mL) in patients with HF is determined primarily by severity of renal dysfunction and not by structural or functional cardiac condition.
BNP, pcg/mL
Mild (744.56 143.76)
Creatinine, 1.96 6 mg/dL Ejection 39.43 6 Fraction, % LV Internal 5.34 6 Dimension, Diastole, cm LV Internal 3.99 6 Dimension, Systole, cm LV Mass, g 285.4 6 LV Mass Index 151.8 6 Mitral 1.5 6 Regurgitation Tricuspid 1.37 6 Regurgitation Left Atrium, cm 4.37 6 LV Outflow 101.22 6 Tract Time Velocity Integral, cmI 16.03 6 E/E0
Moderate (24346 2890.61)
High (7271.76 3248.04)
2.48
2.25 6 2.52
3.43 6 2.81
19.22
26.28 6 16.61
30.61 6 16.59
1.1
6.17 6 1.04
5.52 6 0.93
1.41
5.11 6 1.47
4.4 6 1.23
Mild/ Moderate/ Moderate High Mild/High NS
p ! 0.01 p!0.001
p !0.001 NS
p!0.05
p !0.001 p!0.01
NS
p !0.001 p ! 0.05 NS
107.17 368.62 6 116.92 347.8 6 133.59 p !0.001 NS 56.45 190.03 6 72.5 203.86 6 64.9 p ! 0.05 NS 0.61 1.88 6 0.66 1.65 6 0.54 p ! 0.01 NS
p ! 0.05 p ! 0.001 NS
0.53
1.72 6 0.74
1.76 6 0.8
p ! 0.01 NS
p!0.01
0.75 39.5
4.68 6 0.52 86.11 6 27.71
4.63 6 0.74 85.05 6 29.37
p ! 0.01 NS p!0.05 NS
NS p!0.05
7.66
20.14 6 6.9
p!0.05
p!0.05
19.9 6 7.12
Fig. 1. ROC curves for diagnosing LV diastolic dysfunction. History and physical variables added to ICG and BNP in ‘‘All predictors’’ curve include weight, height, gender, blood pressure, history of coronary disease, stent, MI, CABG, angina, hypertension, COPD, stroke, renal dysfunction and dyspnea.
NS
117
116 Noninvasive Impedance Cardiography Measurements Increase the Diagnostic Ability of B-Type Natriuretic Peptide for Diastolic Heart Failure Susan R. Isakson1, Lori B. Daniels1,2, Jennifer Beede1, Paul Clopton1, Alan S. Maisel1,2; 1Dept of Medicine, Div of Cardiology, Veteran’s Affairs Medical Center, La Jolla, CA; 2Dept of Medicine, Div of Cardiology, University of California, San Diego, San Diego, CA Introduction: Echocardiography, the gold standard for diagnosis of left ventricular (LV) dysfunction, is costly and sometimes unavailable. Diagnosis of diastolic heart failure using B-type natriuretic peptide (BNP) is difficult, as it is not overly sensitive nor specific. Non-invasive measurements of cardiac output by impedance cardiography (ICG) may be a useful adjunct to BNP for diagnosing diastolic LV dysfunction. Methods: We enrolled 229 patients with no known LV dysfunction from the VA Medical Center echocardiography lab. Patients received non-invasive cardiac output measurements (BioZ, CardioDynamics) and plasma BNP measurements (Centaur, Bayer Diagnostics), on the same day as their echocardiograms. Results: Diastolic dysfunction was present in 127 of the 229 patients (55.5 %). Receiver operator curves (ROC) for diagnosis of LV diastolic dysfunction were created using BNP (AUC 5 0.60), using ICG variables (AUC 5 0.68), and using the combination of ICG variables with BNP (AUC 5 0.70). Addition of history and exam variables to ICG and BNP increased the diagnostic value of the tests (AUC 5 0.83). ICG variables used in ROC analysis were selected using logistic regression and included log transformed cardiac index, stroke index, stroke volume, log transformed systemic vascular resistance index, velocity index, left cardiac work index, and LV ejection time. Conclusions: Non-invasive hemodynamic measurements increase the accuracy of BNP for diagnosis of diastolic dysfunction.
Usefulness of B-Type Natriuretic Peptide and Procollagen Peptide Predicting the Presence or Absence of Left Ventricular Hypertrophy in Patients with Hypertension Byung-Su Yoo1, Jang-Young Kim1, Seung-Hwan Lee1, Junghan Yoon1, Kyung-Hoon Choe1; 1Cardiology, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea Background: Interstitial fibrosis and neurohormonal marker are suggested to contribute to left ventricular hypertrophy (LVH). We evaluated the relationship between B-type natriuretic peptide (BNP) or procollagen markers and LVH, and tested the hypothesis whether procollagen peptide and BNP would be useful to exclude echocardiographic LVH. Method: Baseline blood samples were collected at entry from 87 patients (hypertension 83, control 13) with newly developed hypertension without prior medications. We measured serum levels of BNP (Biosite), and collagen synthesis marker (propeptide of type I or III procollagen: PINP or PIIINP, Orion) in patients LVH was defined by echocardiography. We excluded the patients with diabetes, atrial fibrillation, coronary artery disease, renal disease, abnormal liver function and bone or connective tissue disorders. Results: In all hypertension patients (age 5 63, male 63%), median values of the peptides were BNP 36 pg/ml (5e118), PIIINP 2.6 (1.4e5.8) ug/l and PINP 32 (16e96) ug/l. 38 patients (46%) had echocardiographic LVH. Patients with LVH were significantly older and had higher PINP, PIIINP and BNP concentrations and higher systolic blood pressure (p!0.05). BNP (p50.018) and PINP (p50.043) were the biochemical parameters that independently predicted left ventricular mass index. The optimal cut-off points for the diagnosis of LVH were 43 pg/ml for BNP (sensitivity 69%, specificity 74%), 38 ug/l for PINP (sensitivity 59%, specificity 51%) and 3.2 ug/l for PIIINP (sensitivity 42%, specificity 46%). Only 1of 38 patients with values of BNP and PINP less than the optimal cut-off point had echocardiographic LVH, resulting in a high negative predictive value of 97% for the 2 blood tests combined to exclude LVH. Conclusion: In hypertensive patients, echocardiographic LVH was related with BNP and procollagens levels, and can be excluded on the basis of blood sample for the determination of BNP and PINP.
BNP, pcg/mL
Mild (744.56 143.76)
Creatinine, 1.96 6 mg/dL Ejection 39.43 6 Fraction, % LV Internal 5.34 6 Dimension, Diastole, cm LV Internal 3.99 6 Dimension, Systole, cm LV Mass, g 285.4 6 LV Mass Index 151.8 6 Mitral 1.5 6 Regurgitation Tricuspid 1.37 6 Regurgitation Left Atrium, cm 4.37 6 LV Outflow 101.22 6 Tract Time Velocity Integral, cmI 16.03 6 E/E0
Moderate (24346 2890.61)
High (7271.76 3248.04)
2.48
2.25 6 2.52
3.43 6 2.81
19.22
26.28 6 16.61
30.61 6 16.59
1.1
6.17 6 1.04
5.52 6 0.93
1.41
5.11 6 1.47
4.4 6 1.23
Mild/ Moderate/ Moderate High Mild/High NS
p ! 0.01 p!0.001
p !0.001 NS
p!0.05
p !0.001 p!0.01
NS
p !0.001 p ! 0.05 NS
107.17 368.62 6 116.92 347.8 6 133.59 p !0.001 NS 56.45 190.03 6 72.5 203.86 6 64.9 p ! 0.05 NS 0.61 1.88 6 0.66 1.65 6 0.54 p ! 0.01 NS
p ! 0.05 p ! 0.001 NS
0.53
1.72 6 0.74
1.76 6 0.8
p ! 0.01 NS
p!0.01
0.75 39.5
4.68 6 0.52 86.11 6 27.71
4.63 6 0.74 85.05 6 29.37
p ! 0.01 NS p!0.05 NS
NS p!0.05
7.66
20.14 6 6.9
p!0.05
p!0.05
19.9 6 7.12
Fig. 1. ROC curves for diagnosing LV diastolic dysfunction. History and physical variables added to ICG and BNP in ‘‘All predictors’’ curve include weight, height, gender, blood pressure, history of coronary disease, stent, MI, CABG, angina, hypertension, COPD, stroke, renal dysfunction and dyspnea.
NS
117
116 Noninvasive Impedance Cardiography Measurements Increase the Diagnostic Ability of B-Type Natriuretic Peptide for Diastolic Heart Failure Susan R. Isakson1, Lori B. Daniels1,2, Jennifer Beede1, Paul Clopton1, Alan S. Maisel1,2; 1Dept of Medicine, Div of Cardiology, Veteran’s Affairs Medical Center, La Jolla, CA; 2Dept of Medicine, Div of Cardiology, University of California, San Diego, San Diego, CA Introduction: Echocardiography, the gold standard for diagnosis of left ventricular (LV) dysfunction, is costly and sometimes unavailable. Diagnosis of diastolic heart failure using B-type natriuretic peptide (BNP) is difficult, as it is not overly sensitive nor specific. Non-invasive measurements of cardiac output by impedance cardiography (ICG) may be a useful adjunct to BNP for diagnosing diastolic LV dysfunction. Methods: We enrolled 229 patients with no known LV dysfunction from the VA Medical Center echocardiography lab. Patients received non-invasive cardiac output measurements (BioZ, CardioDynamics) and plasma BNP measurements (Centaur, Bayer Diagnostics), on the same day as their echocardiograms. Results: Diastolic dysfunction was present in 127 of the 229 patients (55.5 %). Receiver operator curves (ROC) for diagnosis of LV diastolic dysfunction were created using BNP (AUC 5 0.60), using ICG variables (AUC 5 0.68), and using the combination of ICG variables with BNP (AUC 5 0.70). Addition of history and exam variables to ICG and BNP increased the diagnostic value of the tests (AUC 5 0.83). ICG variables used in ROC analysis were selected using logistic regression and included log transformed cardiac index, stroke index, stroke volume, log transformed systemic vascular resistance index, velocity index, left cardiac work index, and LV ejection time. Conclusions: Non-invasive hemodynamic measurements increase the accuracy of BNP for diagnosis of diastolic dysfunction.
Usefulness of B-Type Natriuretic Peptide and Procollagen Peptide Predicting the Presence or Absence of Left Ventricular Hypertrophy in Patients with Hypertension Byung-Su Yoo1, Jang-Young Kim1, Seung-Hwan Lee1, Junghan Yoon1, Kyung-Hoon Choe1; 1Cardiology, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea Background: Interstitial fibrosis and neurohormonal marker are suggested to contribute to left ventricular hypertrophy (LVH). We evaluated the relationship between B-type natriuretic peptide (BNP) or procollagen markers and LVH, and tested the hypothesis whether procollagen peptide and BNP would be useful to exclude echocardiographic LVH. Method: Baseline blood samples were collected at entry from 87 patients (hypertension 83, control 13) with newly developed hypertension without prior medications. We measured serum levels of BNP (Biosite), and collagen synthesis marker (propeptide of type I or III procollagen: PINP or PIIINP, Orion) in patients LVH was defined by echocardiography. We excluded the patients with diabetes, atrial fibrillation, coronary artery disease, renal disease, abnormal liver function and bone or connective tissue disorders. Results: In all hypertension patients (age 5 63, male 63%), median values of the peptides were BNP 36 pg/ml (5e118), PIIINP 2.6 (1.4e5.8) ug/l and PINP 32 (16e96) ug/l. 38 patients (46%) had echocardiographic LVH. Patients with LVH were significantly older and had higher PINP, PIIINP and BNP concentrations and higher systolic blood pressure (p!0.05). BNP (p50.018) and PINP (p50.043) were the biochemical parameters that independently predicted left ventricular mass index. The optimal cut-off points for the diagnosis of LVH were 43 pg/ml for BNP (sensitivity 69%, specificity 74%), 38 ug/l for PINP (sensitivity 59%, specificity 51%) and 3.2 ug/l for PIIINP (sensitivity 42%, specificity 46%). Only 1of 38 patients with values of BNP and PINP less than the optimal cut-off point had echocardiographic LVH, resulting in a high negative predictive value of 97% for the 2 blood tests combined to exclude LVH. Conclusion: In hypertensive patients, echocardiographic LVH was related with BNP and procollagens levels, and can be excluded on the basis of blood sample for the determination of BNP and PINP.