Combining tissue Doppler echocardiography and B-type natriuretic peptide in the evaluation of left ventricular filling pressures: review of the literature and clinical recommendations

Left Atrial Coupling Index Predicts Heart Failure in Patients with End Stage Renal Disease

Background and Objectives: We aimed to ascertain the predictive power of the left atrial coupling index (LACI) in patients with end stage renal disease (ESRD) for heart failure with preserved ejection fraction (HFpEF). Materials and Methods: This is a retrospective study including 100 subjects between 18 and 65 years of age with ESRD and not on dialysis treatment. Patients were divided into groups with and without HFpEF. The LACI was defined as the ratio of the left atrial volume index (LAVI) to the a' wave in tissue Doppler imaging (TDI). Statistical analyses were performed, including univariate and multivariate regression analyses. Results: The mean age of the participants was 47 ± 13.3 years. Individuals with HFpEF exhibited a higher LACI. Univariate and multivariate regression analyses demonstrated that the predictive capacity of the LACI for HFpEF was considerably higher than that of the LAVI and other echocardiographic parameters. Conclusions: Higher LACI levels were consistently related to the presence of HFpEF in ESRD patients. The LACI can be easily obtained in daily practice using conventional Doppler echocardiographic measurements during left atrial functional assessments.

Relationship Between Results of Pathological Evaluation of Endomyocardial Biopsy and Echocardiographic Indices in Patients With Non-Ischemic Cardiomyopathy

Background: Endomyocardial biopsy (EMB) is a useful modality in diagnosing the origin of cardiomyopathy and the condition of the impaired myocardium. However, the usefulness of obtaining an EMB from the right and left ventricles (RV and LV, respectively), and its associations with echocardiographic parameters, have not been explored. Methods and Results: Ninety-five consecutive patients with non-ischemic cardiomyopathy excluding myocarditis who underwent EMB between July 2017 and May 2019 were studied. Seventy-nine RV and 93 LV biopsy specimens were pathologically analyzed. The relationships among echocardiographic data before EMB and pathologically measured cardiomyocyte diameter (CMD) and interstitial fibrosis (IF) were evaluated. CMD in both LV and RV specimens correlated with echocardiographic LV morphology, but only CMD in the LV was significantly correlated with cardiac function evaluation, including LV ejection fraction, E' and E/E'. In contrast, there were no significant correlations between IF in either the LV or RV and any echocardiographic parameters measured. Furthermore, CMD of both ventricles was significantly correlated with B-type natriuretic peptide (BNP) concentration at EMB, whereas IF of the LV was barely related and IF of the RV was not significantly correlated with BNP concentrations. Conclusions: Pathologically evaluated CMD of EMB specimens of the LV may be more related to functional parameters for heart failure status and LV geometry on echocardiographic examination, than IF.

A simple formula to predict echocardiographic diastolic dysfunction-electrocardiographic diastolic index

BACKGROUND

Diastolic dysfunction (DD) in transthoracic echocardiography (TTE), which is a poorly understood entity due to its limited treatment, is frequently encountered in daily clinical practice of cardiology. An electrocardiographic (ECG) index to predict echocardiographic DD has not been elucidated yet. We aim to exhibit an electrocardiographic diastolic index (EDI) to predict TTE DD with high sensitivity and specificity.

MATERIALS AND METHODS

In this retrospective investigation, we tested the DD predictive value of EDI [aVL R amplitude × (V1S amplitude + V5R amplitude)/D1 P amplitude] on 204 consecutive adult patients without known coronary artery disease. Patients were divided into tertiles according to their EDI starting from the lowest one. The power of the EDI was also compared with the subunits of its formula by a receiver operating curve (ROC) analysis.

RESULTS

After adjustment for confounding baseline variables, EDI in tertile 3 was associated with 24.2-fold hazard ratio of DD (odds ratio 25.2, 95% confidence interval [CI] 11.2-51.1, p < 0.001). The Spearman correlation analysis revealed moderate correlation between E/e' and EDI. A ROC analysis showed that the optimal cut-off value of the EDI to predict DD was 8.53 mV with 70% sensitivity and 70% specificity (area under the curve 0.78; 95% CI 0.71-0.84; p < 0.001).

CONCLUSION

The electrocardiographic diastolic index (EDI), which is an inexpensive, feasible, and easy to use formula, appears to have a considerable role to predict diastolic dysfunction (DD) in adult patients.

B-Type Natriuretic Peptides (BNP) and Tissue Doppler E/e´ Before and After 4 Weeks Standard Treatment of African Heart Failure Subjects: The ABU-BNP Longitudinal Survey

BACKGROUND

The study aimed at determining the response of BNP and tissue Doppler (TD) E/e´ to standard heart failure (HF) therapy in an African black population as data on these are lacking in Africa. BNP assessment in relation to HF severity and its association with its predictors were also determined.

METHODS

It was a longitudinal-analytical study with a one month follow-up among 100 HF patients seen at Ahmadu Bello University Teaching Hospital, Zaria-Nigeria. Two-way Repeated Measures ANOVA determined BNP levels before and after treatment according to the HF severity. Wilcoxon-Signed Ranks test determined the difference in BNP and TD E/e´ before and after treatment. Pearson's correlation assessed log-transformed BNP's association with its predictors.

RESULTS

BNP significantly (p<0.001) rose with increasing severity of HF from 386.6 ± 186.5 pg/mL to 581.7 ± 299.0 pg/mL to 805.0 ± 484.0 pg/mL in the NYHA II-IV HF, respectively, with consequent fall in a similar fashion following treatment. The Median (IQR) BNP levels reduced significantly (p<0.001) from 450 (362.5, 712.5) to 275.0 (225, 375.2) pg/mL with a 38.9% reduction over 4 weeks associated with significant improvement in TD E/e´, structural and functional parameters. Ln10BNP was significantly (p<0.001) positively correlated to TD E/e´ before (r=0.51) and after treatment (r=0.43). Likewise, Ln10BNP was significantly (p<0.05) negatively correlated to ejection fraction & fractional shortening before and after treatment.

CONCLUSION

BNP and tissue Doppler can serve as useful tools in the assessment of the effectiveness of African HF treatment and functional capacity over 4 weeks. TD E/e´ may be a reliable non-invasive estimate of left ventricular filling pressures and diastolic dysfunction.

Clinical implication of LAVI over A' ratio in patients with acute coronary syndrome

Purpose

The ratio of the left atrial volume index (LAVI) and late diastolic mitral annular velocity (A') is a useful echocardiographic index for identifying advanced left ventricular (LV) diastolic dysfunction in patients with dyspnoea. We investigated the clinical implications and prognostic value of the aforementioned ratio (LAVI/A') in patients with ST elevation (STE) or non-STE (NSTE) acute coronary syndrome (ACS).

Methods

We studied 212 patients with ACS. All patients underwent electrocardiography, echocardiography and measurement of plasma B-type natriuretic peptide (BNP) level on admission. The study endpoints were hospitalisation and mortality because of heart failure (HF).

Results

There was a significant, moderate positive correlation between LAVI/A' and natural logarithm (Ln) BNP level among the participants (r=0.48, p<0.0001). During a mean follow-up of 17 months, eight patients died and nine patients were hospitalised because of HF. The receiver operating characteristics curve indicated that LAVI/A'≥3.0 predicted these events (log-rank, p=0.0021). A significant and moderate positive correlation existed between LAVI/A' and Ln BNP level in the NSTE-ACS group (n=128; r=0.58, p<0.0001). However, the correlation between LAVI/A' and Ln BNP level was weaker in the STE-ACS group (n=84; r=0.33, p=0.0017).

Conclusion

LAVI/A' was related to plasma BNP levels in patients with ACS, particularly in those with NSTE-ACS. This index was useful for predicting cardiac events in patients with ACS.

Myocardial strain may predict exercise tolerance in patients with reduced and mid-range ejection fraction

BACKGROUND

Conventional echocardiographic parameters, such as rest ejection fraction, perform poorly in the prediction of exercise tolerance in heart failure. The aim of the present study was to evaluate the contribution of hemodynamic instability in the observed lower functional capacity and investigate the role of left ventricular strain for the prediction of stress test duration in obese hypertensive patients with reduced ejection fraction.

METHODS

Sixty-one patients with reduced ejection fraction underwent treadmill exercise echocardiography. Systolic and diastolic echocardiographic parameters were recorded. Moreover, the presence of hemodynamic instability was assessed through N-terminal pro B-type natriuretic peptide (NT-proBNP) measurements at baseline and peak exercise.

RESULTS

Rest and peak NT-proBNP levels, and their difference, were significantly correlated with mean global strain at peak, which was the only parameter associated with changes in NT-proBNP levels. Rest and peak mean global strain were found to be predictive for the duration of treadmill stress test. In particular, mean global strain, but not left ventricular ejection fraction, was independently correlated with exercise ability.

CONCLUSIONS

Stress echocardiography may provide important information regarding exercise tolerance in obese hypertensive patients with reduced ejection fraction, mainly through the evaluation of left ventricular strain. The obtained evidence may also have prognostic value, particularly in the early stages of the syndrome.

Chagas cardiomyopathy: The potential effect of benznidazole treatment on diastolic dysfunction and cardiac damage in dogs chronically infected with Trypanosoma cruzi

Cardiac involvement represents the main cause of mortality among patients with Chagas disease, and the relevance of trypanocidal treatment to improving diastolic dysfunction is still doubtful. In the present study, we used a canine model infected with the benznidazole-sensitive Berenice-78 Trypanosoma cruzi strain to verify the efficacy of an etiologic treatment in reducing the parasite load and ameliorating cardiac muscle tissue damage and left ventricular diastolic dysfunction in the chronic phase of the infection. The effect of the treatment on reducing the parasite load was monitored by blood PCR and blood culture assays, and the effect of the treatment on the outcome of heart tissue damage and on diastolic function was evaluated by histopathology and echo Doppler cardiogram. The benefit of the benznidazole-treatment in reducing the parasite burden was demonstrated by a marked decrease in positive blood culture and PCR assay results until 30days post-treatment. At this time, the PCR and blood culture assays yielded negative results for 82% of the treated animals, compared with only 36% of the untreated dogs. However, a progressive increase in the parasite load could be detected in the peripheral blood for one year post-treatment, as evidenced by a progressive increase in positive results for both the PCR and the blood culture assays at follow-up. The parasite load reduction induced by treatment was compatible with the lower degree of tissue damage among animals euthanized in the first month after treatment and with the increased cardiac damage after this period, reaching levels similar to those in untreated animals at the one-year follow-up. The two infected groups also presented similar, significantly smaller values for early tissue septal velocity (E' SIV) than the non-infected dogs did at this later time. Moreover, in the treated animals, an increase in the E/E' septal tissue filling pressure ratio was observed when compared with basal values as well as with values in non-infected dogs. These findings strongly suggest that the temporary reduction in the parasite load that was induced by benznidazole treatment was not able to prevent myocardial lesions and diastolic dysfunction for long after treatment.

Echocardiographic estimation of left ventricular filling pressures in patients with mitral valve stenosis

Background

Estimation of left ventricular end-diastolic pressure (LVEDP) among patients with mitral valve disease may help to explain their symptoms. However, conventional Doppler measurements have limitations in predicting LVEDP in this group of patients. The aim of this study was to construct a Doppler-derived LVEDP prediction model based on the combined analysis of transmitral and pulmonary venous flow velocity curves.

Methods

Thirty-three patients with moderate to severe mitral stenosis (MS) who had indications for left heart catheterisation enrolled. Two-dimensional, M-mode, colour Doppler and tissue Doppler imaging indices, such as annular early diastolic velocity (Ea), isovolumic relaxation time (IVRT), pulmonary vein systolic and diastolic flow velocities, velocity propagation, left atrium area (LAA), interval between the onset of mitral E and annular Ea (TE–Ea), and Tei index were obtained. LVEDP was measured in all patients during left cardiac catheterisation. Linear correlation and multiple linear regressions were used for analysis.

Results

The mean of LVEDP was 9.9 ± 5.3 mmHg. In univariate analysis, the only significant relationship was noted with LAA (p = 0.05, R² = 0.11). However, in multivariate regression, LAA, Tei index and Ea remained in the model to predict LVEDP (p = 0.02, R² = 0.26). For prediction of LVEDP ≥ 15 mmHg, the best model consisted of LAA, IVRT and Ea, and had a sensitivity of 85% and specificity of 85%.

Conclusion

Our results provided evidence that, in patients with moderate to severe MS, LVEDP can be estimated by combining Doppler echocardiographic variables of mitral flow. However, more studies are required to confirm these results.

Relationship between pulse pressure variation and echocardiographic indices of left ventricular filling pressure in critically ill patients

BACKGROUND

Pulse pressure variation (PPV) is a dynamic index of fluid responsiveness. This parameter helps clinicians in improving haemodynamic status while avoiding potential fluid overload. Echocardiographic indices, such as E/E' ratio and left atrial (LA) strain by speckle tracking echocardiography (STE), are used to estimate left ventricular (LV) filling pressures. This study aimed at exploring the relationship between PPV and echocardiographic indices of LV filling pressures in critically ill patients.

METHODS

Twenty-two patients (mean age of 50.9 ± 21.6, male/female = 15/7) admitted to intensive care unit, and requiring mechanical ventilation and invasive arterial pressure monitoring, were studied. In all patients, two independent operators assessed simultaneously PPV, using a pulse contour method, mean E/E' ratio and peak atrial longitudinal strain (PALS) by means of STE. PALS values were obtained by averaging LA segments measured in the 4-chamber and 2-chamber views (global PALS).

RESULTS

A significant negative correlation was found between mean E/E' ratio and PPV (R(2) = -0.76; P<0.001). A positive correlation between global PALS and PPV was found (R(2) = 0.80, P<0.001). Mean global PALS of 26.2% demonstrated excellent accuracy (Area Under Roc Curve = 0.86, P<0.001), and good sensitivity (92%) and specificity (86%) in predicting a PPV >15%.

CONCLUSION

In a group of mechanically ventilated patients PPV, derived from pulse contour analysis, and echocardiographic preload parameters were well correlated. Global PALS by STE provided better estimation of PPV than mean E/E' ratio. PALS seems a potential alternative to PPV in assessing fluid responsiveness in critically ill patients.

Association of N-terminal pro-brain natriuretic peptide and hemodynamic parameters measured by impedance cardiography in patients with essential hypertension

The aim of this study was to evaluate the association of NT-proBNP with clinical and hemodynamic assessment in 156 patients with arterial hypertension. NT-proBNP correlated positively with, i.e. age (r=0.310, p=0.00008), mean blood pressure (MBP; r=0.199, p=0.0136), Heather index (HI; r=0.375, p<0.00001) and negatively with thoracic fluid content (TFC; r=-0.300, p=0.0002). The patients with higher NT-proBNP were older (46.1 versus 40.6 years, p=0.001), with higher MBP (102.6 versus 98.5 mm Hg, p=0.0043), HI (14.54 versus 11.93 Ohm s2, p=0.009) and lower TFC (27.5 versus 29.4 1/kOhm, p=0.0032). The independent predictors of higher NT-proBNP were: age, MBP and HI.

Comparison and Reproducibility of Techniques for Fluid Status Assessment in Chronic Hemodialysis Patients

BACKGROUND

Several methods have been developed to assess the hydration status in chronic hemodialysis (HD) patients. The aim of this study was to compare body bioimpedance spectroscopy (BIS) with ultrasound (US) lung comet score (ULCs), B-type natriuretic peptide (BNP) and inferior vena cava diameter (IVCD) by US for the estimation of dry weight before and after HD and to analyze all methods in terms of fluid status variations induced by HD. An additional aim of this study was to establish the interoperator reproducibility of these methods.

METHODS

Two nephrologists evaluated BIS, ULCs, IVCD during inspiration (min) and expiration (max), the inferior vena cava collapsibility index (IVCCI) as well as BNP before and after HD in 30 patients. The same operators measured BIS, ULCs and IVCD in 28 HD patients in a blinded fashion.

RESULTS

There was a significant reduction in BIS, ULCs, IVCD and BNP after HD (p < 0.001), but a less significant reduction in IVCCI (p = 0.13). There was a significant correlation between BIS and ULCs, BNP and indexed IVCD (IVCDi)min (p < 0.05) before and after HD, and between BIS and IVCDimax only before HD.

CONCLUSION

All methods were able to describe hyperhydration before and after HD, except for IVCCI after HD. All techniques correlated with BIS before HD. After HD, ULCs correlated better with BIS than IVCD in terms of evaluation of fluid status. It could be expected that the ULCs can give a real-time evaluation of interstitial water. The reproducibility of the measurement of BIS, IVCD and ULCs between the two operators was high.

Ruling out cardiac failure: cost-benefit analysis of a sequential testing strategy with NT-proBNP before echocardiography

OBJECTIVES

To estimate the possible economic benefit of a sequential testing strategy with NT-proBNP to reduce the number of echocardiographies.

METHODS

Retrospective study in a third-party payer perspective. The costs were calculated from three Swedish counties: Blekinge, Östergötland, and Uppland. Two cut-off levels of NT-proBNP were used: 400 and 300 pg/mL. The cost-effectiveness of the testing strategy was estimated through the short-term cost avoidance and reduction in demand for echocardiographies.

RESULTS

The estimated costs for NT-proBNP tests and echocardiographies per county were reduced by 33%-36% with the 400 pg/mL cut-off and by 28%-29% with the 300 pg/mL cut-off. This corresponded to a yearly cost reduction of approximately €2-5 million per million inhabitants in these counties.

CONCLUSION

The use of NT-proBNP as a screening test could substantially reduce the number of echocardiographies in the diagnostic work-up of patients with suspected cardiac failure, as well as the associated costs.

Prognostic value of combining echocardiography and natriuretic peptide levels in patients with heart failure

Heart failure (HF) is still a global public health issue, despite the enormous progress made in its diagnosis and treatment. More often than not, acute or chronic decompensated HF leads to hospitalization and presents a dismal prognosis. Evidently, clinical symptoms alone are not reliable enough guidance for the HF treatment; therefore, parameters able to identify adverse prognoses are valuable in tailoring treatment regimens for individual patients. Echocardiography and natriuretic peptides (NPs) have demonstrated their capacities in giving independent diagnostic and prognostic information regarding patients with HF. Although abnormalities either of an echocardiographic index of left ventricular function or of an NP denote an increased risk of mortality or HF, the highest risk comes from abnormalities of both left ventricular function and NP levels. In this review, we survey the most recent publications exploring the utility of NP levels and echocardiographic indices integration, claimed to offer powerful incremental prognostication in patients with established HF.

Left atrial volume index over late diastolic mitral annulus velocity (LAVi/A') is a useful echo index to identify advanced diastolic dysfunction and predict clinical outcomes

BACKGROUND

Combined interpretation of late diastolic mitral annulus velocity (A') with left atrial volume index (LAVi) may have additional benefits in the assessment of diastolic dysfunction.

HYPOTHESIS

The LAVi/A' ratio may be useful in the identifying advanced diastolic dysfunction (ADD) and predicting clinical outcomes in patients with dyspnea.

METHODS

We enrolled 395 consecutive patients hospitalized with dyspnea (New York Heart Association class II-IV) and performed transthoracic Doppler echocardiography and B-type natriuretic peptide (BNP) measurement. LAVi/A' values were evaluated in terms of diagnosing ADD and predicting clinical outcome.

RESULTS

On the receiver operation characteristic curve analysis for the determination of ADD, the area under the curves of LAVi/A' in the entire population was comparable to those of BNP (0.94 vs 0.93, P = 0.845) and mitral E/E' (0.94 vs 0.93, P = 0.614) and higher than that of LAVi (0.94 vs 0.87; P = 0.014). A LAVi/A' of 4.0 was the best cut-off value to identify ADD. During a median follow-up of 31.9 months (range, 0.3 to 45.7 months), the group with LAVi/A' ≥4.0 had a higher incidence of primary composite outcomes (cardiac death and/or rehospitalization for heart failure) than the group with LAVi/A'<4.0 (25.0% vs 3.3%, P < 0.001). LAVi/A' ≥4.0 was an independent predictor of clinical outcomes (odds ratio, 3.245; 95% confidence interval, 1.386-7.598; P = 0.007).

CONCLUSIONS

As a new echo index, LAVi/A' is a useful parameter to identify ADD and predict clinical outcomes in patients with dyspnea.

Left atrial longitudinal strain by speckle tracking echocardiography correlates well with left ventricular filling pressures in patients with heart failure

Background

The combination of early transmitral inflow velocity and mitral annular tissue Doppler imaging (E/Em ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However E/Em ratio has a significant gray zone and its accuracy in patients with heart failure is debated. Left atrial (LA) deformation analysis by speckle tracking echocardiography (STE) was recently proposed as an alternative approach to estimate LV filling pressures. This study aimed at exploring the correlation of LA longitudinal function by STE and Doppler measurements with direct measurements of LV filling pressures in patients with heart failure.

Methods

A total of 36 patients with advanced systolic heart failure (ejection fraction ≤35%), undergoing right heart catheterization, were studied. Simultaneously to pulmonary capillary wedge pressure (PCWP) determination, peak atrial longitudinal strain (PALS) and mean E/Em ratio were measured in all subjects by two independent operators. PALS values were obtained by averaging all segments (global PALS), and by separately averaging segments measured in the 4-chamber and 2-chamber views.

Results

Not significant correlation was found between mean E/Em ratio and PCWP (R = 0.15). A close negative correlation between global PALS and the PCWP was found (R = -0.81, p < 0.0001). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.93) and excellent sensitivity and specificity of 100% and 93%, respectively, to predict elevated filling pressure using a cutoff value less than 15.1%. Bland-Altman analysis confirmed this close agreement between PCWP estimated by global PALS and invasive PCWP (mean bias 0.1 ± 8.0 mmHg).

Conclusion

In a group of patients with advanced systolic heart failure, E/Em ratio correlated poorly with invasively obtained LV filling pressures. However, LA longitudinal deformation analysis by STE correlated well with PCWP, providing a better estimation of LV filling pressures in this particular clinical setting.