Classification of left ventricular diastolic function using American Society of Echocardiography Guidelines: agreement among echocardiographers

Diastolic function assessment with four-dimensional flow cardiovascular magnetic resonance using automatic deep learning E/A ratio analysis

BACKGROUND

Diastolic left ventricular (LV) dysfunction is a powerful contributor to the symptoms and prognosis of patients with heart failure. In patients with depressed LV systolic function, the E/A ratio, the ratio between the peak early (E) and the peak late (A) transmitral flow velocity, is the first step to defining the grade of diastolic dysfunction. Doppler echocardiography (echo) is the preferred imaging technique for diastolic function assessment, while cardiovascular magnetic resonance (CMR) is less established as a method. Previous four-dimensional (4D) Flow-based studies have looked at the E/A ratio proximal to the mitral valve, requiring manual interaction. In this study, we compare an automated, deep learning-based and two semi-automated approaches for 4D Flow CMR-based E/A ratio assessment to conventional, gold-standard echo-based methods.

METHODS

Ninety-seven subjects with chronic ischemic heart disease underwent a cardiac echo followed by CMR investigation. 4D Flow-based E/A ratio values were computed using three different approaches; two semi-automated, assessing the E/A ratio by measuring the inflow velocity (MVvel) and the inflow volume (MVflow) at the mitral valve plane, and one fully automated, creating a full LV segmentation using a deep learning-based method with which the E/A ratio could be assessed without constraint to the mitral plane (LVvel).

RESULTS

MVvel, MVflow, and LVvel E/A ratios were strongly associated with echocardiographically derived E/A ratio (R2 = 0.60, 0.58, 0.72). LVvel peak E and A showed moderate association to Echo peak E and A, while MVvel values were weakly associated. MVvel and MVflow EA ratios were very strongly associated with LVvel (R2 = 0.84, 0.86). MVvel peak E was moderately associated with LVvel, while peak A showed a strong association (R2 = 0.26, 0.57).

CONCLUSION

Peak E, peak A, and E/A ratio are integral to the assessment of diastolic dysfunction and may expand the utility of CMR studies in patients with cardiovascular disease. While underestimation of absolute peak E and A velocities was noted, the E/A ratio measured with all three 4D Flow methods was strongly associated with the gold standard Doppler echocardiography. The automatic, deep learning-based method performed best, with the most favorable runtime of ∼40 seconds. As both semi-automatic methods associated very strongly to LVvel, they could be employed as an alternative for estimation of E/A ratio.

Recurrence of Atrial Fibrillation in Dependence of Left Atrial Volume Index

BACKGROUND/AIM

Despite advances in the treatment strategies of patients with atrial fibrillation (AF), the risk of AF recurrences is still over 50%. An increased left atrial volume index (LAVI) reflects left ventricular diastolic dysfunction (DD) and deterioration of the LA function. This study aims to determine AF recurrence following cardioversion (CV) or catheter ablation for AF (pulmonary vein isolation; PVI) in dependence of DD and LAVI.

PATIENTS AND METHODS

One hundred and sixty-two patients with paroxysmal or persistent AF in whom either CV or PVI were performed were included and followed over a mean of 22.9±3.8 months. Recurrence was defined as any recurrence of AF that occurred 3 months following the procedure. DD and LAVI were assessed using transthoracic echocardiography (TTE).

RESULTS

Recurrent AF occurred in 100 (61.7%) patients, predominantly following CV [CV 41 (76.2%) vs. PVI 59 (54.6%), p<0.0001]. Both DD and an increased LAVI were more common in the recurrence-group [DD 46.0% vs. 14.5%, p=0.0001; LAVI (ml/m²) 49.0±18.6 vs. 26.3±7.0, p<0.0001]. ROC analysis revealed LAVI>36 ml/m² as cut-off (p<0.0001, AUC=0.92, 95%CI=0.87-0.97, sensitivity=76%, specificity=94%). In the multivariate analysis, DD (HR=1.6, 95%CI=1.3-2.1, p=0.04) and LA enlargement (defined as LAVI>36 ml/m² with HR=2.1, 95%CI=1.8-2.7, p<0.0001) could be identified as independent predictors of AF recurrence after attempting to control the heart rhythm.

CONCLUSION

LA enlargement and DD are independent risk factors associated with AF recurrence after initial successful rhythm control attempt. These findings have implications for timing of either ablation or CV.

Feasibility and Accuracy of Tele-Echocardiography, With Examinations by Nurses and Interpretation by an Expert via Telemedicine, in an Outpatient Heart Failure Clinic

OBJECTIVES

To study the feasibility and accuracy of focused echocardiography by nurses supported by near-real-time interpretation via telemedicine by an experienced cardiologist.

METHODS

Fifty consecutive patients were included from an outpatient heart failure (HF) clinic. Limited echocardiography was performed by 1 of 3 specialized nurses. The echocardiograms were transferred by a secure transfer model for near-real-time interpretation to 1 out-of-hospital cardiologist, assessing, among others, the left ventricular (LV) internal diameter, end-diastolic volume, ejection fraction, left atrial (LA) indexed end-systolic volume, mitral early inflow velocity (E), the ratio of E to mitral late inflow, and the ratio of E to the mitral annular early diastolic velocity. The reference method was echocardiography by 1 of 4 experienced cardiologists.

RESULTS

The median age of the population (46% women) was 79 (range, 33-95) years. The assessment and quantification of LA and LV dimensions, volumes, and functional indices were feasible in 94% or more via the telemedical approach. The agreement with reference measurements was very high by the telemedical approach. The mean duration ± SD of the complete telemedical approach from the start of echocardiography until the cardiologist's report was received by the caregiving nurse was 1.32 ± 0.36 (range, 1.58) hours. The correlations with reference to the above-specified indices were r = 0.75 to 0.94.

CONCLUSIONS

Limited echocardiography by nurses in an outpatient heart failure clinic, supported by interpretation by an out-of-hospital cardiologist, was feasible and reliable. This may reduce geographic disparities and allow more patients to benefit from the advantages of implementing focused echocardiography by noncardiologists in diagnostics and follow-up.

Direct measurement of cardiac stiffness using echocardiographic shearwave imaging during open-chest surgery: A pilot study in human

PURPOSE

Cardiac stiffness is a marker of diastolic function with a strong prognostic significance in many heart diseases that is not measurable in clinical practice. This study investigates whether elastometry, a surrogate for organ stiffness, is measurable in the heart using ShearWave Imaging.

METHODS

In 33 anesthetized patients scheduled for cardiac surgery, ShearWave imaging was acquired epicardially using a dedicated ultrasound machine on the left ventricle parallel to the left anterior descending coronary artery in a loaded heart following the last cardiac beat. Cardiac elastometry was measured offline using the Young modulus with customized software.

RESULTS

Overall, the ejection fraction was 61 ± 10%. E/A and E/e' ratios were 1.0 ± 0.5 and 10.5 ± 4.1, respectively. Cardiac elastometry averaged 15.3 ± 5.3 kPa with a median of 18 kPa. Patients with high elastometry >18 kPa were older (P = .04), had thicker (P = .02) but smaller LV (P = .004), had larger left atria (P = .05) and a higher BNP level (P = .04). We distinguished three different transmural elastometry patterns: higher epicardial, higher endocardial, or uniformly distributed elastometry.

CONCLUSION

Elastometry measurement was feasible for the human heart. This surrogate for cardiac stiffness dichotomized patients with low and high elastometry, and provided three different phenotypes of transmural elastometry with link to diastolic function.

Impact of epicardial adipose tissue volume upon left ventricular dysfunction in patients with mild-to-moderate aortic stenosis: A post-hoc analysis

Background

Aortic stenosis (AS) may lead to diastolic dysfunction and later on heart failure (HF) with preserved left ventricular ejection fraction (HFpEF) via increased afterload and left-ventricular (LV) hypertrophy. Since epicardial adipose tissue (EAT) is a metabolically active fat depot that is adjacent to the myocardium and can influence cardiomyocytes and LV function via secretion of proinflammatory cytokines, we hypothesized that high amounts of EAT, as assessed by computed tomography (CT), may aggravate the development and severity of LV hypertrophy and diastolic dysfunction in the context of AS.

Methods

We studied 50 patients (mean age 71 ± 9 years; 9 women) in this preliminary study with mild or moderate AS and mild to severe LV diastolic dysfunction (LVDD), diagnosed by echocardiography, who underwent non-contrast cardiac CT and echocardiography. EAT parameters were measured on 2nd generation dual source CT. Conventional two-dimensional echocardiography and Tissue Doppler Imaging (TDI) was performed to assess LV function and to derive myocardial straining parameter. All patients had a preserved LV ejection fraction > 50%. Data was analysed using Pearson’s correlation.

Results

Only weak correlation was found between EAT volume or density and E/é ratio as LVDD marker (r = -.113 p = .433 and r = .260, p = .068 respectively). Also, EAT volume or density were independent from Global Strain Parameters (r = 0.058 p = .688 and r = -0.207 p = .239). E/é ratio was strongly associated with LVDD (r = .761 p≤0.0001) and Strain Parameters were moderately associated with LV Ejection Fraction (r = -.669 p≤0.001 and r = -.454 P≤0.005).

Conclusions

In this preliminary study in patients with AS, the EAT volume and density as assessed by CT correlated only weakly with LVDD, as expressed by the commonly used E/é ratio, and with LV strain function. Hence, measuring EAT volume and density may neither contribute to the prediction nor upon the severity of LVDD, respectively.

Assessment of left ventricular diastolic function after Transcatheter aortic valve implantation in aortic stenosis patients by echocardiographic according to different guidelines

Background

To evaluate the detailed dynamic change of left ventricular diastolic function (LVDF) by echocardiography in aortic stenosis (AS) patients receiving transcatheter aortic valve implantation (TAVI) and compare LVDF classification according to 2009 ASE/EAE and 2016 ASE/EACVI recommendations.

Methods

Thirty-five AS patients receiving TAVI underwent echocardiography the day before operation (PRE), on the third day (3D), in the first-month (1 M) and the six-month (6 M) after TAVI. LVDF was analyzed using 2D and doppler imaging to get parameters including E/A, E/e’, isovolumic relaxation time (IVRT), deceleration time, LA area, LA volume index (LAVI) and systolic tricuspid regurgitation velocity (TR). LVDF classification was evaluated four times for each patient according to 2009 and 2016 recommendations respectively and the results were compared.

Results

The decrease of IVRT and TR occurred immediately post surgery up to 1-month. Improvement of E/e’ occurred late from 3-day to 1-month. LA area and LAVI decreased continuously shortly after operation till 6-month. Forty-four percent (62/140) by 2009 recommendations were reclassified with different grades when using 2016 guidelines. Comparing PRE and 6 M, with 2009 guidelines, 19 patients improved 1 grade, 8 patients improved 2 grades; with 2016 guidelines, 9 patients improved 1 grade, 13 patients improved 2 grades, 1 patient improved 3 grades.

Conclusions

The conventional 2D echocardiography could effectively reflect variation process of LVDF in AS patients after TAVI. For LVDD classification, obvious differences resulted by the 2009 and updated recommendations were found, and more patients can be regarded as benefiting from TAVI by 2016.

recommendations.

Functional Diagnostic Methods in Cardiac Prognosis in Major Abdominal Surgery in Patients with Heart Disease or Over 65 Years Old

PURPOSE OF THE STUDY

Evaluation of the value of the results of the use of cardiac functional examination methods for the stratification of the risk of developing cardiovascular complications in planned abdominal surgical interventions in patients over 65 years of age or with cardiac pathology.

MATERIALS AND METHODS

The study included 179 patients over 65 years of age or with a history of heart disease who underwent elective abdominal surgery. The median age was 70 years. During the operation and for 30 days after it, cardiac complications were recorded: severe (myocardial infarction, stroke, death from cardiovascular disease), others (strokes of exertional angina, ischemic dynamics of the ST segment on the electrocardiogram - ECG - rest, paroxysmal fibrillation / flutter atrial). All patients underwent basic examination - examination, anamnesis, ECG, blood test, assessment of respiratory function, ECG monitoring. Additionally, echocardiography (EchoCG) and ergospirometry (ESM) were performed.

RESULTS

In 30 (16.8 %) patients, various MTRs were detected: 6 (3.4 %) of fatal myocardial infarctions, 2 (1.1 %) of fatal strokes; 3 (1.7 %) cases of sudden cardiac death, angina attacks were recorded in 4 (2.2 %) patients, 7 (3.9 %) had ischemic ECG dynamics, 11 (6.1 %) had fibrillation episodes or atrial flutter. Chronic obstructive pulmonary disease, intervention on the colon, blood hemoglobin level &lt;100 g / l, serum creatinine &gt;103 μmol / l, presence of any pathological changes in the resting ECG were associated with the development of SSO; according to EchoCG - VTI (linear velocity integral) in the outflow tract of the left ventricle (LV) &lt;21.5 cm, volume of the left atrium&gt; 57 ml, global LV myocardial deformity is less than 18 %, increase in heart rate (HR) at the 1st minute load test&gt; 27 %, peak oxygen consumption at ESM &lt;15.8 ml / kg / min. The optimal plan for preoperative examination in men is to perform a basic model, and for women it is advisable to combine a basic examination with an ESM or an assessment of the degree of myocardial deformity using the speckle-tracking method for EchoCG.

CONCLUSION

The risk of perioperative MTS during planned abdominal operations in patients older than 65 years or with a history of heart disease is relatively high - 16.8 %. When assessing the risk associated with the operation, it is advisable to additionally conduct echocardiography with VTI assessment in the LV outflow tract and myocardial deformity indicators, as well as ESM with the determination of HR increase in the 1st minute of the test and peak oxygen consumption.

Investigating Shear Wave Physics in a Generic Pediatric Left Ventricular Model via In Vitro Experiments and Finite Element Simulations

Shear wave elastography (SWE) is a potentially valuable tool to noninvasively assess ventricular function in children with cardiac disorders, which could help in the early detection of abnormalities in muscle characteristics. Initial experiments demonstrated the potential of this technique in measuring ventricular stiffness; however, its performance remains to be validated as complicated shear wave (SW) propagation characteristics are expected to arise due to the complex non-homogenous structure of the myocardium. In this work, we investigated the (i) accuracy of different shear modulus estimation techniques (time-of-flight (TOF) method and phase velocity analysis) across myocardial thickness and (ii) effect of the ventricular geometry, surroundings, acoustic loading, and material viscoelasticity on SW physics. A generic pediatric (10-15-year old) left ventricular model was studied numerically and experimentally. For the SWE experiments, a polyvinylalcohol replicate of the cardiac geometry was fabricated and SW acquisitions were performed on different ventricular areas using varying probe orientations. Additionally, the phantom's stiffness was obtained via mechanical tests. The results of the SWE experiments revealed the following trends for stiffness estimation across the phantom's thickness: a slight stiffness overestimation for phase speed analysis and a clear stiffness underestimation for the TOF method for all acquisitions. The computational model provided valuable 3-D insights in the physical factors influencing SW patterns, especially the surroundings (water), interface force, and viscoelasticity. In conclusion, this paper presents a validation study of two commonly used shear modulus estimators for different ventricular locations and the essential role of SW modeling in understanding SW physics in the pediatric myocardium.

Treatment-associated change in apelin concentration in patients with hypertension and its relationship with left ventricular diastolic function

OBJECTIVE

We examined the change in apelin concentration and its relationship with left ventricular diastolic function in patients treated for hypertension.

METHODS

Ninety treatment-naive patients with newly diagnosed hypertension and 33 age- and sex-matched control subjects were prospectively enrolled. Patients with hypertension were randomized to treatment either with telmisartan 80 mg or amlodipine 10 mg. Apelin concentration was measured and echocardiography was performed at baseline and after 1 month of treatment.

RESULTS

The data of 77 patients and 33 controls were analyzed. Mean age, gender, baseline blood pressure, apelin levels, and echocardiographic measurements were similar between the treatment groups (p>0.05 for all). Apelin concentration was significantly lower in patients with hypertension than in controls. There was a significant increase in apelin level after 1 month of treatment in both groups (0.32±0.17 vs. 0.38±0.17 ng/dL in telmisartan group, p=0.009, and 0.27±0.13 vs. 0.34±0.18 ng/dL in amlodipine group, p=0.013). Diastolic function improved significantly in both groups (p<0.05) but was not significantly associated with change in apelin concentration.

CONCLUSION

Apelin concentration increased significantly after 1 month of effective treatment with telmisartan or amlodipine to a similar extent. Change in apelin concentration was not associated with improvement in diastolic function.

Application of a simplified definition of diastolic function in severe sepsis and septic shock

BACKGROUND

Left ventricular diastolic dysfunction is common in patients with severe sepsis or septic shock, but the best approach to categorization is unknown. We assessed the association of common measures of diastolic function with clinical outcomes and tested the utility of a simplified definition of diastolic dysfunction against the American Society of Echocardiography (ASE) 2009 definition.

METHODS

In this prospective observational study, patients with severe sepsis or septic shock underwent transthoracic echocardiography within 24 h of onset of sepsis (median 4.3 h). We measured echocardiographic parameters of diastolic function and used random forest analysis to assess their association with clinical outcomes (28-day mortality and ICU-free days to day 28) and thereby suggest a simplified definition. We then compared patients categorized by the ASE 2009 definition and our simplified definition.

RESULTS

We studied 167 patients. The ASE 2009 definition categorized only 35 % of patients. Random forest analysis demonstrated that the left atrial volume index and deceleration time, central to the ASE 2009 definition, were not associated with clinical outcomes. Our simplified definition used only e' and E/e', omitting the other measurements. The simplified definition categorized 87 % of patients. Patients categorized by either ASE 2009 or our novel definition had similar clinical outcomes. In both definitions, worsened diastolic function was associated with increased prevalence of ischemic heart disease, diabetes, and hypertension.

CONCLUSIONS

A novel, simplified definition of diastolic dysfunction categorized more patients with sepsis than ASE 2009 definition. Patients categorized according to the simplified definition did not differ from patients categorized according to the ASE 2009 definition in respect to clinical outcome or comorbidities.

Left ventricular function assessment in cirrhosis: Current methods and future directions

Cirrhotic cardiomyopathy has been defined as a chronic cardiac dysfunction in patients with cirrhosis characterized by impaired contractile responsiveness to stress and/or altered diastolic relaxation with electrophysiological abnormalities in the absence of other known cardiac disease. Non-invasive cardiovascular imaging modalities play a major role in unmasking systolic and diastolic dysfunction in patients with cirrhosis. Echocardiography has been the most commonly used modality for assessing myocardial function in these patients. Conventional echocardiographic indices rely on several assumptions that may limit their applicability in patients with a hyperdynamic circulation. Newer imaging modalities may contribute to a more accurate diagnosis of cardiovascular abnormalities in cirrhotic patients, thereby influencing clinical management. We aimed to review the different non-invasive imaging technologies currently used for assessing left ventricular systolic and diastolic function in cirrhosis, as well as to describe new imaging modalities with potential clinical applicability in the near future.

Interstudy heterogeneity of definitions of diastolic dysfunction severely affects reported prevalence

Aims

The aim of this article is to examine how the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE) recommendations on the classification of diastolic dysfunction (DDF) are interpreted in the scientific community and to explore how variations in the DDF definition affect the reported prevalence.

Methods and results

A systematic review of studies citing the EACVI/ASE consensus document ‘Recommendations for the evaluation of left ventricular diastolic function by echocardiography’ was performed. The definition of DDF used in each study was recorded. Subsequently, several possible interpretations of the EACVI/ASE classification scheme were used to obtain DDF prevalence in a community-based sample (n = 714). In the systematic review, 60 studies were included. In 13 studies, no specification of DDF definition was presented, a one-level classification tree was used in 13, a two-level classification tree in 18, and in the remaining 16 studies, a DDF definition was presented but no grading of DDF was performed. In 17 studies, the DDF definition relied solely on early diastolic tissue velocity and/or left atrial size. In eight of these studies, a single parameter was used, in two studies the logical operator AND was used to combine two or more parameters, and the remaining seven studies used the logical operator OR. The resulting prevalence of DDF in the community-based sample varied from 12 to 84%, depending on the DDF definition used.

Conclusion

A substantial heterogeneity of definitions of DDF was evident among the studies reviewed, and the different definitions had a substantial impact on the reported prevalence of DDF.

Nonalcoholic Fatty Liver Disease Is Independently Associated with Early Left Ventricular Diastolic Dysfunction in Patients with Type 2 Diabetes

Accumulating evidence suggests that nonalcoholic fatty liver disease (NAFLD) is associated with left ventricular diastolic dysfunction (LVDD) in nondiabetic individuals. To date, there are very limited data on this topic in patients with type 2 diabetes and it remains uncertain whether NAFLD is independently associated with the presence of LVDD in this patient population. We performed a liver ultrasonography and trans-thoracic echocardiography (with speckle-tracking strain analysis) in 222 (156 men and 66 women) consecutive type 2 diabetic outpatients with no previous history of ischemic heart disease, chronic heart failure, valvular diseases and known hepatic diseases. Binary logistic regression analysis was used to examine the association between NAFLD and the presence/severity of LVDD graded according to the current criteria of the American Society of Echocardiography, and to identify the variables that were independently associated with LVDD, which was included as the dependent variable. Patients with ultrasound-diagnosed NAFLD (n = 158; 71.2% of total) were more likely to be female, overweight/obese, and had longer diabetes duration, higher hemoglobin A1c and lower estimated glomerular filtration rate (eGFR) than those without NAFLD. Notably, they also had a remarkably greater prevalence of mild and/or moderate LVDD compared with those without NAFLD (71% vs. 33%; P<0.001). Age, hypertension, smoking, medication use, E/A ratio, LV volumes and mass were comparable between the two groups of patients. NAFLD was associated with a three-fold increased odds of mild and/or moderate LVDD after adjusting for age, sex, body mass index, hypertension, diabetes duration, hemoglobin A1c, eGFR, LV mass index and ejection fraction (adjusted-odds ratio 3.08, 95%CI 1.5–6.4, P = 0.003). In conclusion, NAFLD is independently associated with early LVDD in type 2 diabetic patients with preserved systolic function.

Endothelial nitric oxide synthase single nucleotide polymorphism and left ventricular function in early chronic kidney disease

Background

Chronic kidney disease (CKD) is associated with accelerated cardiovascular disease and heart failure. Endothelial nitric oxide synthase (eNOS) Glu298Asp single nucleotide polymorphism (SNP) genotype has been associated with a worse phenotype amongst patients with established heart failure and in patients with progression of their renal disease. The association of a cardiac functional difference in non-dialysis CKD patients with no known previous heart failure, and eNOS gene variant is investigated.

Methods

140 non-dialysis CKD patients, who had cardiac magnetic resonance (CMR) imaging and tissue doppler echocardiography as part of two clinical trials, were genotyped for eNOS Glu298Asp SNP retrospectively.

Results

The median estimated glomerular filtration rate (eGFR) was 50mls/min and left ventricular ejection fraction (LVEF) was 74% with no overt diastolic dysfunction in this cohort. There were significant differences in LVEF across eNOS genotypes with GG genotype being associated with a worse LVEF compared to other genotypes (LVEF: GG 71%, TG 76%, TT 73%, p = 0.006). After multivariate analysis, (adjusting for age, eGFR, baseline mean arterial pressure, contemporary CMR heart rate, total cholesterol, high sensitive C-reactive protein, body mass index and gender) GG genotype was associated with a worse LVEF, and increased LV end-diastolic and systolic index (p = 0.004, 0.049 and 0.009 respectively).

Conclusions

eNOS Glu298Asp rs1799983 polymorphism in CKD patients is associated with relevant sub-clinical cardiac remodelling as detected by CMR. This gene variant may therefore represent an important genetic biomarker, and possibly highlight pathways for intervention, in these patients who are at particular risk of worsening cardiac disease as their renal dysfunction progresses.

Two-dimensional echocardiography in the assessment of long-term prognosis in patients with pulmonary arterial hypertension

OBJECTIVE

To investigate the relationship between cardiac diastolic dysfunction and outcomes in patients with pulmonary arterial hypertension (PAH) and to clarify the potential effect of two-dimensional echocardiography (2D-echo) on prognostic value in patients with PAH.

METHODS

Patients diagnosed with PAH (as WSPH (World Symposia on Pulmonary Hypertension) classification I) confirmed by right heart catheterization (RHC), received targeted monotherapy or combination therapy. 2D-echo parameters, World Health Organization (WHO) functional classification and 6-minute walking distance (6MWD) were recorded. The clinical prognosis of patients was assessed by the correlation between echo parameters and clinical 6MWD using receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifty-eight patients were included. Left and right ventricular diastolic dysfunction (LVDD and RVDD) scores measured by 2D-echo had good correlation with 6MWD at baseline (rLVDD  = -0.699; rRVDD  = -0.818, both P < 0.001) and at last follow-up (rLVDD  = -0.701; rRVDD  = -0.666, both P<0.001). Furthermore, bi-ventricular (LVDD + RVDD) scores measured by 2D-echo had a better correlation with 6MWD at baseline and last follow-up (r =  0.831; r = -0.771, both P < 0.001). ROC curve analysis showed that the area under curves (AUCs) for LVDD score, RVDD score and (LVDD + RVDD) scores were 0.823 (P < 0.0001), 0.737 (P = 0.0002), and 0.825 (P < 0.0001), respectively. Compared with ROC analysis of other single parameters, cardiac diastolic function score was more accurate in predicting survival in patients with PAH.

CONCLUSION

LVDD score, RVDD score and (LVDD + RVDD) scores yielded a comprehensive quantitative assessment of LV and RV diastolic function that correlated moderately with clinical functional parameters and might be useful in the assessment of PAH.

Association between physical activity measurements and key parameters of cardiopulmonary exercise testing in patients with heart failure

BACKGROUND

A hallmark characteristic of heart failure (HF) is reduced physical activity (PA) patterns. The relationship between key cardiopulmonary exercise testing (CPX) variables and PA patterns has not been investigated. Therefore, we evaluated PA patterns in patients with ischemic HF and its relationship to peak oxygen consumption (VO2), the minute ventilation/carbon dioxide production (VE/VCO2) slope, and the oxygen uptake efficiency slope (OUES).

METHODS AND RESULTS

Sixteen patients with HF wore an accelerometer for six days to measure total steps/day as well as percentage of time at light, moderate, and vigorous PA. Symptom-limited CPX was performed on a treadmill using a ramping protocol. Total steps correlated with VO2 (r = 0.64 P < .05), the VE/VCO2 slope (r = -0.72; P < .05), and the OUES (0.63; P < .05). The percentage of time at light-intensity PA correlated with the VE/VCO2 slope (r = 0.58; P < .05) and the OUES (r = -0.51; P < .05). The percentage of time at vigorous-intensity PA correlated with peak VO2 (r = 0.55; P < .05) and the VE/VCO2 slope (r = -0.52; P < .05).

CONCLUSIONS

PA assessed by accelerometer is significantly associated with key CPX variables in patients with HF.