Comparison of dobutamine stress echocardiography, dobutamine SPECT, and adenosine SPECT myocardial perfusion imaging in patients with end-stage renal disease.

OBJECTIVES: We sought to assess and compare the diagnostic accuracy and prognostic value of dobutamine stress echocardiography (DSE), dobutamine SPECT, and adenosine SPECT myocardial perfusion imaging (MPI) in patients with end-stage renal disease (ESRD). BACKGROUND: The optimal stress imaging modality for patients with ESRD has not yet been determined. METHODS: Forty-nine patients with ESRD underwent DSE, dobutamine SPECT MPI, and adenosine SPECT MPI. The primary endpoint of the trial was concordance between stress tests with respect to the presence or absence of ischemia. RESULTS: Agreement on the presence or absence of ischemia between adenosine SPECT MPI and DSE was 69% (kappa = .25, P = NS). Agreement on the presence or absence of ischemia between adenosine and dobutamine SPECT MPI was 77% (kappa = .37, P = <.009). Summed stress scores for adenosine and dobutamine SPECT MPI studies were highly correlated (r = .9, P = <.0001). DSE and SPECT MPI results provided incremental prognostic information when added to clinical variables. CONCLUSIONS: There is moderate concordance between DSE and adenosine SPECT MPI in ESRD patients referred for stress testing. Interobserver agreement was higher for SPECT MPI compared to DSE. Based on these observations, the optimal approach for diagnosing severe coronary artery disease and assessing risk in patients with ESRD has yet to be determined, but appears to warrant further investigation.

Direct comparison of B-type natriuretic peptide (BNP) and amino-terminal proBNP in a large population of patients with chronic and symptomatic heart failure: the Valsartan Heart Failure (Val-HeFT) data.

BACKGROUND: The B-type or brain natriuretic peptides (BNP) and the amino-terminal probrain natriuretic peptide (NT-proBNP) are good markers of prognosis and diagnosis in chronic heart failure (HF). It is unclear, however, whether differences in their biological characteristics modify their clinical correlates and prognostic performance in HF. This work aimed to provide a direct comparison of the prognostic value of BNP and NT-proBNP in patients with chronic and stable HF. METHODS: We measured BNP and NT-proBNP at baseline in 3916 patients enrolled in the Valsartan Heart Failure Trial. To identify the variables associated with both peptides, we conducted simple and multivariable linear regression analyses. We used Cox multivariable regression models to evaluate the independent prognostic value for all-cause mortality, mortality and morbidity, and hospitalization for HF. Prognostic performance was assessed by pairwise comparisons of the area under the curve of receiver-operator characteristic curves. RESULTS: NT-proBNP and BNP had similar relationships with age, left ventrical ejection fraction, and internal diameter and creatinine clearance. Either peptide ranked as the first independent predictor of outcome after adjustment for major confounding clinical characteristics. ROC curves were almost superimposable for all-cause mortality (area under the curve (SE): BNP 0.665 (0.011) vs NT-proBNP 0.679 (0.011); P=0.0734), but NT-proBNP was superior to BNP for predicting mortality and morbidity (P=0.032) or hospitalization for HF (P=0.0143). Overall sensitivity and specificity ranged from 0.590 to 0.696. CONCLUSIONS: The natriuretic peptides BNP and NT-proBNP showed subtle differences in their relation to clinical characteristics and prognostic performance in a large population of patients with chronic and stable HF. They were the most powerful independent markers of outcome in HF.

High levels of troponin T are associated with ventricular remodeling and adverse in-hospital outcome in heart failure.

BACKGROUND: Heart failure progression is associated with ventricular remodeling and ongoing myofibrillar degradation. We hypothesized that myocardial damage, detected by high levels of troponin T, would correlate with echocardiographic measurements of left ventricular remodeling and worse in-hospital course in decompensated heart failure. MATERIAL/METHODS: 159 patients with decompensated heart failure without acute coronary event were included. A troponin T value >0.2 ng/ml in samples taken 6, 12 or 24 hours after admission was considered abnormal. RESULTS: High troponin T levels were identified in 24 patients (15%) (Group 1). Mean age for group 1 was 65.9 vs. 63.7 years in patients with troponin T<0.2 (Group 2) (p=ns). Ischemic etiology in groups 1 and 2 was found in 58.3 and 38.5% (p=0.07). Two-dimensional echocardiograms in groups 1 and 2 revealed higher left ventricular diameters, diastolic (61.7+/-10 vs. 56.9+/-10.3 mm, p=0.041) as well as systolic (49.4+/-13.5 vs. 42.0+/-12.0 mm, p=0.012), and lower ejection fraction (30.1+/-14 vs. 39.0+/-17.7%, p=0.03). Incidence of combined end point of death or refractory heart failure was 20.8 and 3.7% in groups 1 and 2 (p=0.007; OR=6.8; CI95%=1.5-31.2). In a multiple regression model, a history of infarction and chronic obstructive pulmonary disease, tissue hypoperfusion, radiographic pulmonary edema, and high troponin T levels emerged as the independent predictors. CONCLUSIONS: High troponin T levels were found in 15% of patients with acute exacerbation of heart failure; this finding was independently associated with worse prognosis. Echocardiograms suggested that more severe ventricular remodeling is one subjacent mechanism related with biochemically detected myocardial injury in this setting.