Higth-sensitivity T troponin and NT pro B-type natriuretic peptide as predictors of early development of structural heart disease in patients with stage 0 of Chagas disease

Background

Approximately 30% of patients with Chagas disease (ChD) develop structural heart disease at some point in their evolution. There is an asymptomatic period where there is no evidence of cardiac involvement, called stage 0. Prognostic evaluation in this group of patients remains a challenge. On the other hand, the presence of elevated hight-sensitivity T troponin (HS-TnT) and N-terminal pro B-type natriuretic peptide (NT-proBNP) has been documented in the early stages of the ChD. The role of these biomarkers as predictors of early development of structural heart disease in the follow-up of stage 0 ChD has been poorly studied.

Purpose

The aim of this study is to evaluate if HS-TnT and NT-proBNP are a predictor of early development of cardiac structural alterations in the follow up of patients with stage 0 ChD.

Materials and methods

Outpatients with stage 0 of ChD (positive serology, with normal electrocardiogram, 24-hours holter and echocardiogram) were included prospectively. Baseline measurement of HS-TnT and NT-proBNP was performed. The follow-up was carried out with serial echocardiography and 24-hour Holter. The end point of development of structural heart disease was considered, defined as one of the following: left ventricular dilation (diastolic diameter of left ventricle >60 mm in men or >55 mm in women), deterioration of ventricular function (Drop >10 points of Left Ventricular Ejection Fraction (LVEF) or LVEF <50%), Complex ventricular arrhythmia or Atrio-ventricular block ≥ second degree Mobitz II. Univariate and multivariate analysis was performed by cox regression.

Results

Three hundred two patients were included, with 47±9 years old, 46% woman. With a median of follow-up of 34 (interquartile range 19 – 43) months, the end point of development of structural heart disease was presented in 4.6% (n=14 patients). In multivariate analysis both HS-TnT and NT-ProBNP were independent predictors of development of structural heart disease [HR 1.18 (IC95% 1.05–1.33), p=0.003 and HR 1.01 (CI95% 1.00–1.01), p=0.001; respectively]. The area under the Receiver operating characteristic (ROC) curve was calculated, for HS-TnT it was 0.80 (95% CI 0.65–0.93), with a cut-off point for HS-TnT >14 ng/ml and for NT-proBNP it was 0.88 (95% CI 0.83–0.95) with a cut-off point for NT-proBNP >200 pg/ml. The figure shows the Kaplan-Meier curve for HS-TnT and NT-proBNP. In adjusted analysis, HS-TnT >14 ng/ml had a HR 5.27 (CI95% 1.4–18.9), p=0.01 and NT-proBNP HR 3.07 (CI95% 1.01–10.9), P=0.04.

Conclusions

In our population of patients with stage 0 chagas disease, HS-TnT and NT-proBNP were independent predictors of early development of structural heart disease, with good predictive capacity. The baseline measurement of these biomarkers can be useful in the evaluation and follow-up of patients with ChD without initial evidence of cardiac involvement.

Funding Acknowledgement

Type of funding sources: None. Kaplan-Meier curve

Association between the elevation of biomarkers and incipient alterations in ventricular function in patients with Chagas disease without evidence of specific organ damage

Background

Chagas disease (ChD) has a long asymptomatic period, where there is no evidence of myocardial damage. However, incipient alterations in ventricular systo-diastolic function have been described using echocardiography with Tissue Doppler and Strain. On the other hand, the presence of elevated higth-sensitivity T troponin (HS-TnT) and N-terminal pro B-type natriuretic peptide (NT-pro BNP) has been documented in the early stages of the ChD. The association between the elevation of both markers and incipient alterations in ventricular function in patients with ChD without evidence of heart damage has been poorly studied.

Purpose

The aim of this study is to evaluate the prevalence of elevation of both biomarkers (HS-TnT and NT-proBNP) and their association with insipients alterations in systo-diastolic function in patients with ChD without evidence of structural heart affection.

Materials and methods

Outpatients with stage 0 of ChD (positive serology, with normal electrocardiogram, holter and chest teleradiography) were included prospectively. They were divided in three groups according to the dosage of HS-TnT and NT-proBNP. Group 1: patients with both markers within normal values; group 2: patients with elevation of one of the markers (HS-TnT>13 ng/L OR NT-proBNP>125 pg/ml) and group 3: patients with elevation of both markers (HS-TnT>13 ng/L AND NT-proBNP>125 pg/ml). All of them underwent Doppler echocardiography with tissue Doppler.

Results

Two hundred and sixty-one patients were included, with 47±9 years old of age, 44% woman, 86.6% (n=226) in group 1, 9.6% (n=25) in group 2 and 3.8% (n=10) in group 3. Table 1 shows the main results.

Conclusions

Elevation of both markers was found in almost 4% of patients. This elevation was associated with a higher E/e' ratio, E/A ratio, Letf Atrial Area and a lower S'-wave lateral.

Funding Acknowledgement

Type of funding source: None

P1811Association between the autonomic dysfunction and biomarker levels in patients with chagas disease without evidence of structural heart disease

Background

Several studies have shown autonomic dysfunction in early stages of Chagas disease (ChD). These alterations may be involved in the progression of the disease. The Valsalva Ratio (VR) is one of the most used tests to evaluate parasympathetic function, because it is easy and reproducible. On the other hand, the Higth Sensitive T troponin (HS-TnT) and the N-terminal pro B-type natriuretic peptide (NT-proBNP) are specific markers of myocardial damage and elevation of filling pressures, respectively. Both elevations are asociated with higher risk.

The association between autonomic dysfunction and biomarker levels in ChD without evidence of structural heart affection, has been poorly studied.

Purpose

The aim of this study is to evaluate the presence of abnormal VR as an expression of disanutonomy in patients with Chagas without evidence of structural heart disease and its association with HS-TnT and NT-proBNP levels.

Methods

A prospective study was performed, which included outpatients with positive serology for Chagas, with electrocardiogram, ergometry, holter and Doppler echocardiogram within normal parameters. The exclusion criteria were the following: history of ischemic heart disease, neurological diseases, chronic renal failure (clearence <30 ml/min), arterial hypertension and diabetes mellitus. All patients underwent a valsalva maneuver (VM), with continuous recording of the R-R interval by electrocardiogram. The VR was calculated dividing the longest RR interval after VM over the shortest RR interval during VM. Abnormal VR was considerated as a value <1.1. In addition, HS-TnT and NT-proBNP were measured in all patients.

Results

One hundred and forty four patients were included, with 45±8 years old, 44% fameles. The VR was 1.22±0.12, HS-TnT 6.44±3.8 ng/L and the NT-proBNP was 55±44 pg/ml. Abnormal VR was found in 29.1% of patients (n=42).

The abnormal VR group showed a higher level of HS-TnT (8.11±3.8 versus 5.7±3.5 ng/L, p=0.0006) and higher level of NT-proBNP (78±54 versus 45±36 pg/ml, p<0.0001). In addition, the abnormal VR group presented a greater E/e'ratio (9.48±2.5 versus 7.1±1.8, p<0.0001) and greater s wave (0.08±0.02 versus 0.10±0.02 cm/sec, p=0.02).

In the multivariate análisis, abnormal VR was asociated with higher HS-TnT (OR 1.22 (CI 95% 1.04–1.43), p=0.01) and higher E/e'ratio (OR 1.54 (CI95% 1.17–2.02), p=0.001), but not with NT-proBNP (p=0,09).

Conclusions

About one third of patients with ChD without evidence of cardiopaty had autonomic dysfunction. The patients with abnormal VR had higher leves of HS-TnT and NT-proBNP, but in the multivariate analisys only the HS-TnT had associated with abnormal VR.