17 research outputs found
Dynamic left ventricular obstruction: A potential cause of angina in end stage renal disease
Background
Patients with end stage renal disease (ESRD) often have angina which cannot be explained by coronary artery disease (CAD) alone. Symptoms are often attributed to systolic and diastolic dysfunction, arrhythmia or microvascular disease. This study proposes another potential cause for angina in renal failure, namely dynamic left ventricular obstruction (LVO).
Methods
125 renal transplant candidates underwent dobutamine stress echocardiography and coronary angiography. LVO was defined as a peak LV outflow tract gradient > 50 mm Hg.
Results
None of the patients had LVO at rest. 15 (12%) developed obstruction with dobutamine. The mechanism was systolic anterior motion of the mitral valve in 13 and mid cavity obstruction in 2. Of 53 patients with angina, 26% had dynamic LVO compared to only 1% in those without angina ( p = 0.004). The proportion with severe CAD, parameters of systolic and diastolic function and haemoglobin levels were similar in patients with and without angina. Significantly more patients with obstruction had angina (93% vs 28%, p < 0.001). LV end-systolic ( p = 0.03) and LV end-diastolic (LVEDD, p = 0.03) diameter were reduced and LV fractional shortening (LVFS) increased ( p = < 0.001) in those with LVO. Haemoglobin levels, septal wall thickness, estimated LV filling pressure, the proportion with a positive DSE and severe CAD were similar in the 2 groups. LVFS was independently associated with the development of significant obstruction (OR 1.12, 95% CI [1.002, 1.244] p = 0.04).
Conclusions
Dynamic LVO occurs in 26% of ESRD patients with angina. In these patients, the angina could not be explained by severe CAD, impaired systolic or diastolic function. Such patients have smaller LV cavity size and increased LVFS
Dobutamine stress echocardiography and the resting but not exercise electrocardiograph predict severe coronary artery disease in renal transplant candidates
Methods
Coronary angiography, DSE, and baseline cTnT measurements were performed in 118 consecutive patients (mean age 52±12 years, 75 male) with ESRD (mean creatinine 608±272μmol/L) referred for renal transplantation. The mean follow-up period was 1.32±0.48 years. Significant CAD was defined as a reduction in luminal diameter >70% by visual estimation in at least one major epicardial vessel. An abnormal DSE result defined as the development of a new regional wall motion abnormality in one or more normal resting segments or a deterioration of wall motion in one or more resting hypokinetic segments. A baseline cTnT>0.1μg/L was taken as positive.
Results
Significant CAD in at least one vessel was present in 35 patients (30%). The number of patients with significant 3 vessel and 2 vessel disease was 6 and 7, respectively. An abnormal DSE result was present in 36 (31%) patients. Thirty-one (26%) had cTnT>0.1μg/L. Sixty-four (54%) patients were on dialysis and 46 (39%) were diabetic. The sensitivity, specificity, positive and negative predictive values for DSE in detecting significant coronary artery disease were 88%, 94%, 86% and 95%, respectively. The same values for a raised cTnT were 54%, 62%, 40% and 74%, respectively. The combination of an abnormal DSE result and raised cTnT gave values of 61%, 91%, 76%, and 80%, respectively. Over the follow-up period, mortality was significantly higher in those with a raised baseline cTnT but not those with an abnormal DSE result or significant CAD.
Conclusion
DSE is an accurate technique for the detection of significant CAD in renal transplant candidates. An elevated cTnT does not predict significant CAD in this population and when used in conjunction with DSE, reduces the sensitivity of the combined tests. cTnT is an important marker of prognosis in renal transplant candidates
Ischemia-modified albumin predicts mortality in ESRD
Background: The primary study aim is to determine whether ischemia-modified albumin (IMA) levels predict mortality in patients with end-stage renal disease (ESRD). The secondary aim is to determine characteristics of patients with elevated IMA levels.
Methods: A prospective observational study of 114 renal transplantation candidates was performed. All underwent coronary angiography and dobutamine stress echocardiography. The primary end point is total mortality.
Results: During a follow-up period of 2.25 ± 0.71 years, there were 18 deaths; 10 were cardiac related. Diabetes, severe coronary artery disease, positive dobutamine stress echocardiography result, cardiac troponin T (cTnT) level, IMA level, left ventricular (LV) end-systolic diameter, LV ejection fraction, left atrial size, and mitral peak velocity of early filling (E)/early diastolic velocity (Ea) ratio all predicted mortality. The receiver operating characteristic area under the curve for mortality prediction was similar for IMA and cTnT levels. An IMA level of 95 KU/L or greater (n = 46) predicted mortality with a sensitivity of 76% and specificity of 74%. cTnT level of 0.06 ng/mL or greater (≥0.06 μg/L; n = 51) predicted mortality with a sensitivity of 75% and specificity of 72%. Thirty-eight patients (33%) had both IMA and cTnT levels elevated. With multivariate analysis, a positive dobutamine stress echocardiography result (P = 0.003), combined elevated IMA and cTnT levels (P = 0.005), and E/Ea ratio (P = 0.009) were independent prognostic factors. IMA and cTnT levels alone were not independent predictors of mortality. Patients with an elevated IMA level had a significantly larger LV size, decreased LV systolic function, and greater E/Ea ratio compared with those without an increased level.
Conclusion: IMA level predicts mortality in patients with ESRD. Patients with elevated levels have larger LV size, decreased systolic function, and greater estimated LV filling pressures
Cardiac structural and functional abnormalities in end stage renal disease patients with elevated cardiac troponin T
Objectives: To identify in a prospective observational study the cardiac structural and functional abnormalities and mortality in patients with end stage renal disease (ESRD) with a raised cardiac troponin T (cTnT) concentration.
Methods: 126 renal transplant candidates were studied over a two year period. Clinical, biochemical, echocardiographic, coronary angiographic, and dobutamine stress echocardiographic (DSE) data were examined in comparison with cTnT concentrations dichotomised at cut off concentrations of < 0.04 μg/l and < 0.10 μg/l.
Results: Left ventricular (LV) size and filling pressure were significantly raised and LV systolic and diastolic function parameters significantly impaired in patients with raised cTnT, irrespective of the cut off concentration. The proportions of patients with diabetes and on dialysis were higher in both groups with raised cTnT. With a cut off cTnT concentration of 0.04 μg/l but not 0.10 μg/l, significantly more patients had severe coronary artery disease and a positive DSE result. The total ischaemic burden during DSE was similar in cTnT positive and negative patients, irrespective of the cut off concentration used. LV end systolic diameter index and E:Ea ratio were independent predictors of cTnT rises ⩾ 0.04 μg/l and ⩾ 0.10 μg/l, respectively. Diabetes was independently associated with cTnT at both cut off concentrations. Mortality was higher in all patients with raised cTnT.
Conclusions: Patients with ESRD with raised cTnT concentrations have increased mortality. Raised concentrations are strongly associated with diabetes, LV dilatation, and impaired LV systolic and diastolic function, but not with severe coronary artery disease
The diagnostic and prognostic value of tissue Doppler imaging during dobutamine stress echocardiography in end-stage renal disease
Objective: To determine whether a quantitative measurement of peak systolic velocity (PSV) during dobutamine stress echocardiography (DSE) detects severe coronary artery disease (CAD) and predicts mortality in patients with end-stage renal disease.
Methods: One hundred and forty renal transplant candidates had DSE and coronary angiography. DSE analysis was performed using conventional visual wall motion assessment, longitudinal PSV, and combining the two modalities. Failure of PSV to rise by more than 50% predicted an ischemic response. Significant CAD was defined as luminal stenosis greater than 70%.
Results: The number of positive DSE studies according to conventional, PSV, and combined criteria was 41 (30%), 42 (31%), and 46 (34%) respectively. Forty patients (29%) had significant CAD at angiography. The sensitivity, specificity, positive and negative predictive values for conventional DSE analysis were 84, 91, 86, and 90% respectively. The same values for PSV analysis were 86, 92, 86, and 91%, respectively. The same values for the combination of visual and PSV analysis were 88, 94, 87, and 92% respectively. The differences between the three methods were not statistically significant. Sensitivity for single-vessel CAD (P=0.05) and circumflex artery disease (P=0.05) diagnosis was higher with PSV compared with conventional DSE analysis. Failure of PSV to rise by more than 50% during DSE was associated with significantly increased mortality (P=0.001).
Conclusion: A quantitative interpretation of DSE, based on the percentage rise of PSV during stress, accurately detects CAD and predicts prognosis in end-stage renal disease
Mitral peak Doppler E-wave to peak mitral annulus velocity ratio is an accurate estimate of left ventricular filling pressure and predicts mortality in end-stage renal disease
Objective
The study aimed to assess whether the mitral peak Doppler E-wave to peak mitral annulus velocity ratio (E/Ea) estimates left ventricular (LV) filling pressure (LVFP) and predicts mortality in end-stage renal disease.
Methods
In all, 125 candidates for renal transplant were prospectively studied. LV end-diastolic pressure of 15 mm Hg or greater at cardiac catheterization was defined as elevated LVFP.
Results
Severe coronary artery disease, N- terminal pro-B-type natriuretic peptide level, left atrial size, flow propagation velocity, mitral E/Ea ratio, pulmonary atrial reversal velocity, and pulmonary-mitral atrial wave duration predicted an increased LVFP. However, the mitral E/Ea ratio (odds ratio 8.1, 95% confidence interval 5.1-9.6, P = .003) was the only independent predictor. An E/Ea of 15 or more, seen in 31 (25%) patients, predicted increased LVFP with sensitivity of 82% and specificity of 88%, and was associated with increased mortality (P = .005).
Conclusions
In end-stage renal disease, mitral E/Ea ratio 15 or higher accurately predicts increased LVFP and mortality
Evaluation of ischaemia-modified albumin as a marker of myocardial ischaemia in end-stage renal disease
The early diagnosis of myocardial ischaemia is problematic in patients with ESRD (end-stage renal disease). The aim of the present study was to determine whether IMA (ischaemia-modified albumin) increases during dobutamine stress and detects myocardial ischaemia in patients with ESRD. A total of 114 renal transplant candidates were studied prospectively, and all received DSE (dobutamine stress echocardiography). IMA levels were taken at baseline and 1 h after cessation of DSE. A total of 35 patients (31%) had a positive DSE result. Baseline IMA levels were not significantly different in the DSE-positive and -negative groups. The increase in IMA was significantly higher in the DSE-positive group compared with those with no ischaemic response (26.5±19.1 compared with 8.2±9.6 kU/l respectively; P=0.007; where kU is kilo-units). From ROC (receiver operator charactertistic) curve analysis, the optimal IMA increase to predict an ischaemic response was 20 kU/l, with a sensitivity of 81% and a specificity of 72% [area under the curve, 0.80 (95% confidence interval, 0.44–0.94); P=0.03]. There were 18 deaths, ten of which were cardiac in nature over a follow up period of 2.25±0.71 years. An increase in IMA ≥20 kU/l was associated with significantly worse survival (P=0.02). In conclusion, IMA is a moderately accurate marker of myocardial ischaemia in ESRD. Patients with an increase in IMA ≥20 kU/l during DSE had significantly worse survival
Raised plasma N-terminal pro-B-type natriuretic peptide concentrations predict mortality and cardiac disease in end-stage renal disease
N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations are raised in a proportion of patients with heart failure and acute coronary syndrome and provide diagnostic and prognostic information. Inclusion cut-off values vary according to age, sex and estimated glomerular filtration rate (eGFR).1,2 Raised NT-proBNP concentrations are found in a proportion of patients with end-stage renal disease (ESRD). The significance and reasons for this remain uncertain.
The objective of this study was to investigate whether NT-proBNP predicts mortality in a group of patients with ESRD. The secondary end point was to examine differences in patients with and without raised NT-proBNP, according to the cut-off value that best predicted mortality