Filling Pressure Research Articles

Outcome assessment using estimation of left ventricular filling pressure in asymptomatic patients at risk for heart failure with preserved ejection fraction

AimsHigh prevalence and lack of pharmacological treatment are making heart failure with preserved ejection fraction (HFpEF) a growing public health problem. No algorithm for the screening of asymptomatic patients with risk for HFpEF exists to date. We assessed whether HFA/ESC 2007 diagnostic criteria for HFpEF are helpful to investigate the cardiovascular outcome in asymptomatic patients. Methods and resultsWe performed an analysis of the Diagnostic Trial on Prevalence and Clinical Course of Diastolic Dysfunction and Heart Failure (DIAST-CHF) that recruited patients with cardiovascular risk factors. All patients underwent a comprehensive diagnostic workup at baseline. Asymptomatic patients with preserved LVEF (>50%) were selected and classified according to HFA/ESC surrogate criteria for left ventricular elevated filling pressure (mean E/e’ >15 or E/e’ >8 and presence of either NT-proBNP > 220 ng/l, BNP > 200 ng/l or atrial fibrillation) into elevated filling pressure (FPe) or controls. Cardiovascular hospitalizations and all-cause death were assessed for both groups over a 10-year-follow-up.851 asymptomatic patients (age 65.5 ± 7.6 years, 44% female) were included in the analysis. FPe-patients were significantly older (p < 0.001), more often female (p = 0.003) and more often had a history of coronary artery disease, atrial fibrillation and renal dysfunction (p < 0.001, respectively) compared to controls. Incidence of death was significantly higher in the FPe group after a 10-year follow-up (p < 0.001), whereas cardiovascular hospitalization did not differ between groups. ConclusionAsymptomatic patients that fulfill HFA/ESC diagnostic criteria for HFpEF are at higher risk of symptomatic HFpEF and have a worse 10-year-outcome than those who do not fulfill criteria.

Relationship between NT-pro Brain Natriuretic Peptide and Filling Pressures in Ambulatory Patients with Left Ventricular Assist Devices and Accuracy to Detect Need for Optimization

We examined whether N-terminal pro-brain natriuretic peptide (NT-proBNP) can serve as a noninvasive marker of filling pressures in ambulatory patients with continuous flow left ventricular assist devices. We retrospectively identified patients who had an outpatient right heart catheterization and NT-proBNP performed the same day between 01/01/2012 and 12/18/2018 at our institution. We evaluated the correlations between NT- proBNP and right atrial pressure (RA), pulmonary artery pressure (PA) and pulmonary capillary wedge pressure (PCWP). The best cut off for NT-proBNP to predict patients that were hemodynamically optimized (CVP<15 and PCWP<18) was derived as the value that minimized the square of the difference between sensitivity and specificity RESULTS: A total of 40 patients were included in the study, Patients characteristics are shown in Table 1. The median NT-proBNP was 1114 pg/mL(IQR 553-2056). The correlations between NT-proBNP and RA (r = 0.58;p<0.001; Coefficient of variation (CV) = 37%); PA(r = 0.34;p=0.03; CV = 26%) and PCWP (r = 0.45;p=0.004; CV = 32%) are shown in figure 1 panels A, B and C respectively. NT-proBNP ≥1168 pg/mL had a 60 %sensitivity and 61% specificity in identifying non-optimum hemodynamics.(Figure 1 panel D). NT-proBNP level is elevated in ambulatory patients with continuous flow left ventricular assist devices and has a moderate correlation with filling pressures. The best cutoff value identified to predict need of hemodynamic optimization had low sensitivity and specificity.

Left Ventricular Filling Pressures Contribute to Exercise Limitation in Patients with Continuous Flow Left Ventricular Assist Devices.

We sought to determine hemodynamic mechanisms of exercise intolerance in a group of patients with the HeartWare ventricular assist device (VAD) compared to a group of heart failure patients. Twenty VAD and 22 heart failure patients underwent symptom-limited active straight leg raising exercise during right heart catheterization with thermodilution (TD), and upright cycling cardiopulmonary stress testing with cardiac output measurement by inert gas rebreathing (IGR) method. The TD and IGR exercise cardiac indexes were higher in VAD compared with heart failure group (both P < 0.05), although there was only a borderline increase in peak exercise oxygen consumption (VO2) (P = 0.06). Baseline and exercise right heart catheterization pressures were not significantly different between the two groups. The only significant independent predictors of peak VO2 in the heart failure group were exercise heart rate and cardiac index (both P < 0.05). In contrast, for the VAD group only, resting pulmonary arterial wedge and pulmonary arterial mean pressures were independently related to peak VO2 (both P < 0.05). Thus, in heart failure, exercise cardiac index is an important limitation to exercise capacity, and VADs increase exercise cardiac index. However, in VAD patients, this only produces limited benefits as increased pulmonary and pulmonary wedge pressures limit increases in exercise capacity.

Predictors of Increased Left Ventricular Filling Pressure After Transcatheter Atrial Septal Defect Closure

Background: The aim of this study was to identify factors of left ventricular filling pressure (LVFP) elevation following transcatheter atrial septal defect (ASD) closure.Methods and Results: The study involved 97 adult patients with sinus rhythm who underwent both transcatheter ASD closure and transthoracic echocardiography. Elevated LVFP was diagnosed during the first month of follow-up according to the American Society of Echocardiography guidelines: that is, ratio of transmitral early filling to the lateral annular diastolic velocity (lateral E/e’) >13 was used to exclude the effect of the device on the atrial septum. Fifteen patients (15.5%) were diagnosed with increased LVFP during the 1-month follow-up period (median lateral E/e’: from 9.2, IQR, 6.6–10.8; to 15.5, IQR, 13.8–17.8; P<0.001). Independent predictors of LVFP elevation were left ventricular (LV) relative wall thickness, lateral E/e›, and peak tricuspid regurgitation pressure gradient (TRPG) at baseline (OR, 1.67; 95% CI: 1.04–2.69; OR, 1.52; 95% CI: 1.07–2.15; and OR, 1.14; 95% CI: 1.04–1.25; cut-offs: 0.42, 7.5, and 27.0 mmHg, respectively). Median lateral E/e› returned to baseline in most patients with LVFP elevation during 6 months of subsequent follow-up (1-month–6-month follow-up: 15.5, IQR, 13.8–17.8; 11.1, IQR, 8.8–14.8, respectively; P=0.001).Conclusions: The increase in Doppler-estimated LVFP following transcatheter ASD closure may be related to LV hypertrophy, diastolic dysfunction, and peak TRPG in elderly patients.

Echocardiographic Evaluation of Left Ventricular Filling Pressure in Patients With Heart Failure With Preserved Ejection Fraction: Usefulness of Inferior Vena Cava Measurements and 2016 EACVI/ASE Recommendations

The left ventricular filling pressure (LVFP) is correlated to right atrial pressure (RAP) in heart failure. We compared diagnostic value of the inferior vena cava (IVC) measurements to the one of the 2016 echocardiographic recommendations to estimate LVFP in patients with suspected heart failure with preserved ejection fraction (HFpEF). Invasive hemodynamics and echocardiography were obtained within 48 hours in 132 consecutive patients with left ventricular ejection fraction ≥50%, and suspected pulmonary hypertension. Increased LVFP was defined by a pulmonary artery wedge pressure (PAWP) >15 mmHg. Of 83 patients in sinus rhythm, a score of the 2016 recommendations ≥ 2 (E/e' ratio >14 and/or tricuspid regurgitation velocity >2.8 m/s and/or indexed left atrial volume>34 mL /m²) had a positive predictive value (PPV) of 63% for PAWP>15 mmHg, whereas a dilated IVC (>2.1 cm) and/or non-collapsible (≤50%) had a PPV of 82%. The net reclassification improvement was 0.39 (P < .05). In atrial fibrillation (AF), a dilated and/or non-collapsible IVC had an 86% PPV for PAWP>15 mmHg. The correlation between RAP and PAWP was 0.60, with 75.7% concordance (100/132) between dichotomized pressures (both RAP>8 mmHg and PAWP>15 mmHg and vice versa). The IVC size and collapsibility is valuable to identify patients with HFpEF with high LVFP in both sinus rhythm and AF.

Left Atrial Strain Correlates with Elevated Filling Pressures in Pediatric Heart Transplantation Recipients

Noninvasive assessment of diastolic function in pediatric heart transplantation (PHTx) patients is important for monitoring of rejection, cardiac allograft vasculopathy, and nonspecific graft failure. We hypothesized that left atrial strain (LAS) would correlate with pulmonary capillary wedge pressure (PCWP) and that cutoff values to identify elevated left ventricular (LV) filling pressure could be derived for clinical practice and future testing. This was a secondary analysis of a prospectively collected cohort of PHTx patients undergoing same-day cardiac catheterization with biopsy and transthoracic echo. There were 70 patients with 85 clinical encounters. Traditional mitral inflow Doppler, LAS, LV diastolic strain and strain rate, and ratios for mitral E to LV diastolic strain and strain rate were assessed. Correlation with PCWP was performed, and receiver operator characteristic curves were generated for an elevated mean PCWP, acute rejection, and cardiac allograft vasculopathy. Decreased LAS during the atrial reservoir phase (Ɛres) correlated with higher invasively measured PCWP (r=-0.40, P<.001). An Ɛres cutoff of 14.5% had good discriminatory ability for an elevated PCWP (sensitivity 75%, specificity 82%), and Ɛres>22.0% had 100% negative predictive value; Ɛres was superior to other measures of diastolic function. Subanalyses for recent acute rejection (n=9) showed good discriminatory ability for Ɛres of 14.5% (sensitivity 89%, specificity 74%). LAS correlates with invasively measured PCWP and can identify elevated pressures better than traditional and other advanced diastolic function parameters. Use of LAS in PHTx patients may aid in noninvasive monitoring for rejection and nonspecific graft dysfunction.

381 Novel Combined Algorithm to Assess Left Ventricular Diastolic Function and Filling Pressures: Correlation With Filling Pressures and Outcomes

A novel combined algorithm has been proposed utilising guideline recommended diastolic parameters that can be applied to all patients regardless of LVEF. This study sought to determine the haemodynamic and prognostic validity of this new algorithm in patients with myocardial infarction(MI). A retrospective single centre study involving 277 patients with a first-ever MI was performed. Outcomes data were obtained from the national death registry. Echocardiography was performed early post-admission for all patients. Significant diastolic dysfunction (DD) was defined was grade 2/3 DD according to the novel algorithm. Haemodynamic correlation involved 54 patients who underwent either same-day or simultaneous cardiac catheterisation or echocardiography. With respect to outcomes, there were a total of 40 MACE events (median follow-up of 2 years). Significant DD was significantly associated with MACE on Kaplan-Meier analysis: log-rank χ2 22.08(p<0.001). In a multivariate Cox proportional hazards model incorporating significant clinical factors (age, chronic kidney disease) and LVEF, significant DD was the most powerful predictor of outcomes (HR 2.71[95% CI 1.28-5.71]; p=0.008). In the haemodynamic study, LVEDP was noted to be elevated in patients with significant DD: mean LVEDP 21.1+7.9mmHg versus 13.2+6.1mmHg (p=0.001). Receiver operating curves showed an area under the curve of 0.814(p<0.001) for assessing elevated LVEDP. The calculated sensitivity, specificity, positive predictive value(PPV) and negative predictive value for LVEDP>15 mmHg was 41.7%, 87.1%, 78.9%, and 56.3% respectively. Significant DD assessed using the novel combined algorithm (i) was an independent predictor of clinical outcomes and (ii) detects elevated LVEDP with a high specificity and PPV.

P800 Effect of Valsalva Maneuver on echocardiographic systolic and diastolic parameters in patients with acute coronary syndrome, a comparison between normal and high ventricular filling pressures

Abstract Funding Acknowledgements Nil OnBehalf Nil Introduction Echocardiography is used as a useful and common method for the assessments of left and right ventricular (LV &amp; RV) systolic and diastolic functions. Valsalva Maneuver (VM) with the increase in the intra-thoracic and intra-abdominal pressure is often used as a simple, inexpensive and non-invasive method to diagnose some clinical conditions such as heart murmurs. However, in terms of echocardiography, the use of VM is limited to a few parameters for many years. On the other hand, blood level of N-Terminal Pro–B-Type Natriuretic Peptide (NT Pro–BNP) indirectly discriminates normal or high ventricular filling pressure (FP). Purpose The purposes of this research is to provide a comprehensive review of the technique and to compare the effect of VM in ACS patients, with and without elevated FP on either RV and LV diastolic and systolic echocardiographic parameters. Methods Thirty-eight patient, who were diagnosed with possible ACS; Unstable Angina Pectoris, NSTEMI and STEMI, underwent coronary angiography enrolled in this double–blinded clinical trial study. The mild Coronary Artery Disease (CAD) with normal levels of NT Pro–BNP were included in study group one and patients with significant CAD and high level of NT Pro–BNP who underwent PCI were included in study group two. All the systolic and diastolic indicators of both ventricles, totally twenty-four parameters those had mentioned in the academic literature previously, have been evaluated; once before Valsalva and once during stage 2 of the maneuver. Echocardiography is performed by an advanced echo machine and by an expert cardiologist- echocardiographer, which the recorded images were reviewed by the second echocardiographer separately. Results Between the two groups, LV parameter analysis showed significant difference in LV EF pre and post VM. However, there was statistically insignificant difference regarding other systolic as well as diastolic parameters. Between the two groups, RV parameters analysis showed no significant difference in systolic and diastolic parameters pre and post VM. Conclusion To the best of our knowledge, this is the first report assessing post VM changes in four chambers as well as mitral and tricuspid valves parameters in ACS patients with normal versus high level of FP. Previously, LV diastolic dysfunction and Doppler mitral inflow pattern correlation with VM were approved. In the present study, in addition to those known findings from before, except the LV ejection fraction (LVEF) that showed there was statistically significant difference in pre– and post-VM, other systolic parameters, as well as diastolic indicators in either RV and LV, were identical. Therefore, we do not recommend conducting Valsalva maneuver on the rest of the other parameters to diagnose systolic and diastolic dysfunction in ACS patients with mild versus significant CAD who were assumed to have normal or elevated filling pressures.

379 Normal Left Atrial Strain is a Novel, Simple, Reliable and Robust Parameter to Exclude Raised Left Ventricular Filling Pressure - Results from the CATHARSIS Study.

Non-invasive assessment of ventricular filling pressure has typically been confounded by poor correlation of standard echocardiographic parameters vs invasive measurements. The novel measurement of left atrial strain as assessed from the apical four-chamber view on transthoracic echocardiography has been suggested as a surrogate for filling pressure. Patients enrolled in the CATHARSIS study undertook comprehensive echocardiography and contemporaneous left heart catheterization (pre-A pressure) whilst nil by mouth. Left atrial strain was assessed using GE Medical Equipment. Maximum atrial strain (reservoir) was assessed in all patients. 140 patients (age 62.0±12.8, female 22%, ejection fraction 56±11%) had left atrial strain 27.1±7.7% with left ventricular pre-A pressure 10±4mmHg. There was a weak linear correlation between invasive pressures and peak LA Strain (r2=0.2, p=0.001). Using a cut-off of ≤12mmHg for normal pre-A pressure and a cut-off of ≥28% for normal left atrial strain yielded a 92% positive predictive power for normal LA Strain predicting normal pre-A pressure. At a threshold of 28%, a reduced left atrial strain did not accurately predict normal vs raised left atrial pressure. Left atrial strain is a novel and feasible parameter which correlates with left ventricular filling pressures. A normal left atrial strain value (≥28%) is highly predictive of normal left ventricular filling pressures.

281 Accuracy of the E/e’ Ratio as a Measure of Left Ventricular Filling Pressures in Patients with Non ST-Elevation Myocardial Infarction

281 Accuracy of the E/e’ Ratio as a Measure of Left Ventricular Filling Pressures in Patients with Non ST-Elevation Myocardial Infarction

356 Incremental Value of Left Atrial Strain in Evaluation of Left Ventricular Filling Pressures in Patients With Indeterminate E/e’: Invasive and Echocardiographic Correlation From the CATHARSIS Study

356 Incremental Value of Left Atrial Strain in Evaluation of Left Ventricular Filling Pressures in Patients With Indeterminate E/e’: Invasive and Echocardiographic Correlation From the CATHARSIS Study

Hemodynamic Validation of the E/e’ Ratio as a Measure of Left Ventricular Filling Pressure in Patients With Non-ST Elevation Myocardial Infarction

The E/e' ratio has an established role in the assessment of left ventricular filling pressure (LVFP) in stable patients, but its accuracy in acute myocardial ischemia is less well established. The aim of this study was to validate the relation between the E/e' ratio and invasively measured LVFP in patients with non-ST elevation myocardial infarction (NSTEMI). A total of 120 unselected patients with NSTEMI underwent cardiac catheterization with measurement of left ventricular end-diastolic pressure (LVEDP; elevated ≥15 mm Hg) and Doppler echocardiography with either simultaneous (n = 30) or same-day (n = 90) measurement of E/e'. Patients were aged 64.1 ± 11.8 years, 72% were male and mean left ventricular ejection fraction was 48.0 ± 20.9%. Septal, lateral, and average E/e' ratios all showed a significant correlation with LVEDP (Pearson's r: 0.42, 0.43, 0.48, respectively [all p <0.001]). Receiver operating characteristics curves showed an area under the curve of 0.72, 0.72, and 0.75 (all p <0.001) for septal, lateral, and average E/e', respectively. The sensitivity, specificity, positive (PPV), and negative (NPV) predictive values for the guideline-recommended threshold of average E/e' >14 for elevated LVEDP was 27%, 93%, 79%, and 44%, respectively. Utilizing lower E/e' boundaries of 6, 7, and 8 for lateral, average, and medial E/e', respectively, improved the NPV to ≥80% for each parameter. In conclusion, the E/e' ratio is a robust measure of LVFP during acute NSTEMI using upper and lower thresholds to achieve a high PPV and NPV, respectively, with the use of adjunctive guideline-recommend measures required in patients with nonconclusive E/e'.

Observational Study of Noninvasive Venous Waveform Analysis to Assess Intracardiac Filling Pressures During Right Heart Catheterization

BackgroundOutpatient monitoring and management of patients with heart failure (HF) reduces hospitalizations and health care costs. However, the availability of noninvasive approaches to assess congestion is limited. Noninvasive venous waveform analysis (NIVA) uses a unique physiologic signal, the morphology of the venous waveform, to assess intracardiac filling pressures. This study is a proof of concept analysis of the correlation between NIVA value and pulmonary capillary wedge pressure (PCWP) and the ability of the NIVA value to predict PCWP > 18 mmHg in subjects undergoing elective right heart catheterization (RHC). PCWP was also compared across common clinical correlates of congestion. Methods and ResultsA prototype NIVA device, which consists of a piezoelectric sensor placed over the skin on the volar aspect of the wrist, connected to a data-capture control box, was used to collect venous waveforms in 96 patients during RHC. PCWP was collected at end-expiration by an experienced cardiologist. The venous waveform signal was transformed to the frequency domain (Fourier transform), where a ratiometric algorithm of the frequencies of the pulse rate and its harmonics was used to derive a NIVA value. NIVA values were successfully captured in 83 of 96 enrolled patients. PCWP ranged from 4–40 mmHg with a median of 13 mmHg. NIVA values demonstrated a linear correlation with PCWP (r = 0.69, P < 0.05). ConclusionsThis observational proof-of-concept study using a prototype NIVA device demonstrates a moderate correlation between NIVA value and PCWP in patients undergoing RHC. NIVA, thus, represents a promising developing technology for noninvasive assessment of congestion in spontaneously breathing patients.

The Relationship between Systemic Filling Pressures with Central Venous Pressure of the Body during Cardiac Surgery

The Relationship between Systemic Filling Pressures with Central Venous Pressure of the Body during Cardiac Surgery

Impact of High Baseline Left Ventricular Filling Pressure on Transcatheter Aortic Valve Replacement Outcomes in Patients with Significant Mitral Annular Calcification

Left ventricular filling pressure (LVFP) has been demonstrated to be a major predictor of poor cardiovascular outcomes. However, estimation of LVFP in patients with aortic stenosis is limited by the high prevalence of significant mitral annular calcification. The aim of this study was to investigate the effect of transcatheter aortic valve replacement on LVFP and the relationship of LVFP to mortality and hospitalization. This was a single-center, retrospective study of 140 consecutive patients in sinus rhythm with significant mitral annular calcification who underwent transcatheter aortic valve replacement for severe aortic stenosis from May 2011 to June 2015. Mean follow-up duration was 3.06±1.48years (minimum, 2.4years; maximum, 6.5years). Diastolic function was assessed using recently proposed criteria for those with significant mitral annular calcification. High LVFP was defined as a mitral E/A ratio > 1.8 or a ratio of 0.8 to 1.8 and isovolumic relaxation time < 80 msec. At baseline, the proportion of patients with high LVFP was 40.7%, similar to 1month (39.7%) (P=.86). However, the proportion of patients with high LVFP was significantly decreased at 1year compared with those at baseline (26.9% vs 40.7%, P=.02). Multivariate analysis showed that high LVFP at baseline significantly increased risk for all-cause mortality compared with patients with normal LVFP (hazard ratio, 2.84; 95% confidence interval, 1.33-6.05; P=.007). High baseline LVFP was associated with a significantly increased all-cause mortality, and LVFP does not improve in the short term but only at 1year after transcatheter aortic valve replacement.

Left Ventricular Filling Pressure as a Useful Marker of Myocardial Injury Following Elective Percutaneous Coronary Intervention

AbstractBackground: Advances in Percutaneous Coronary Inter-vention (PCI) techniques have improved patient outcome. However, occurrence of myonecrosis after elective PCI has been extensively debated.Aim of Study: We investigated the value of the ratio of early transmittal velocity to tissue Doppler mitral annular early diastolic velocity (E/E') in detecting the occurrence of peri-procedural myocardial injury in patients undergoing elective PCI.Patients and Methods: Sixty two patients undergoing elective PCI were recruited prospectively. All participants had EF% >50% and sinus rhythm. E/E' ratio was measured immediately before, and within 24 hours after PCI. CK-MB and cardiac troponin (cTn) were measured in the same day after successful PCI to diagnose myocardial injury.Results: The cohort age was 56.7±9.7 year, and consisted of forty four (71%) males, 49 (27.4%) had ³ two risk factors for CAD, 60% were symptomatic before PCI. Thirty (48.4%) patients had regional wall motion abnormalities (regional Wall Motion Score Index (WMSI): 0.74±0.29). Myocardial injury was diagnosed by elevated cTn in 39 (62.9%) patients. Patients with predilation showed reduction of LVEDP as estimated by D E/E' (8.9±2.9 Vs. 7.9±3.2, p<0.001). Pearson correlation analysis revealed that the E/E' correlated negatively with LV EF% (r=–26, p<0.03), positively with CK-MB and cTn level after PCI (r=.51, p<0.0001), NYHA functional class (r=.72, p<0.001), the number of risk factors, and number of vessel diseased and the number of vessel treated with PCI (r=36, pConclusion: These data suggest that the tissue Doppler derived-index of LV filling pressure (E/E') may be a useful indicator for predicting early myocardial injury after successful PCI. Patients with an elevated E/E' after PCI may need more careful and closer follow-up.

Relation of Left Atrial Volumes in Patients With Myocardial Infarction to Left Ventricular Filling Pressures and Outcomes

The inter-relationships between minimal and maximal left atrial volume index (LAVI), left ventricular filling pressures and survival have not been well studied. This study aimed to compare LAVImin with LAVImax with respect to (1) relative prognostic value, and (2) correlation with left ventricular end-diastolic pressures (LVEDP), in patients with myocardial infarction (MI). A retrospective study involving consecutive patients with a first-ever MI (n = 419) was undertaken. LAVIs were determined using Simpson's biplane method from 2D echocardiography performed the day after admission. LAVmin ≥ 18 mls/m2 and LAVImax ≥ 34 mls/m2 were considered enlarged. The primary end point was composite major adverse cardiovascular events (MACE) (death/MI/heart failure). Correlation between LVEDP and LAVI was assessed in 120 patients who underwent echocardiography and cardiac catheterization either simultaneously (n = 30) or same-day (n = 90). At a median follow-up of 24 months, there were 61 MACE events. On Cox proportional hazards multivariate analysis incorporating significant clinical predictors and LVEF, whereas both LAVImin ≥ 18 mls/m2 (hazard ratio 3.15 [95% confidence interval 1.70 to 5.54], p <0.001) and LAVImax ≥ 34 mls/m2 (hazard ratio 1.79 [95% confidence interval 1.02 to 3.14], p = 0.041) were independent predictors of MACE, LAVImin showed a stronger association. Intermodel comparisons of the model chi-square and Harrell's C-statistic confirmed better prognostication with LAVImin. In the invasive cohort, because LAVImin and LAVImax had a similar correlation with LVEDP ≥ 15 mm Hg (r = 0.41 [p <0.001] vs r = 0.42 [p <0.001]), LAVmin ≥ 18 mls/m2 had a greater sensitivity for LVEDP ≥ 15 mm Hg than LAVImax ≥ 34 mls/m2 (sensitivity 59.4% vs 34.4%). In conclusion, utilizing thresholds of ≥18 and ≥34 mls/m2, respectively, LAVImin was a better predictor of survival than LAVImax, the pathophysiologic basis of which relates to a better sensitivity for elevated left ventricular filling pressures with LAVImin at these thresholds. There may be incremental clinical value in measuring LAVImin alongside LAVImax.

Effect of Pb Filling and Synthesis Pressure Regulation on the Thermoelectric Properties of CoSb3

To take the advantage of the synergy of atom filling and pressure regulation, atom Pb was assumed to play the role of fillers to occupy the Sb-icosahedron voids. In this paper, skutterudite Pb xCo4Sb11.5Te0.5 materials have been synthesized by high-pressure and high-temperature (HPHT) method with 0.5 h processing time. Although the increase of Pb filling rate increased the electrical resistivity of samples, it reduced the thermal conductivity of samples significantly. When the synthesis pressure increased, the Seebeck coefficients of Pb0.2Co4Sb11.5Te0.5 increased, and the thermal conductivity decreased. The crystal morphology and structure of samples, which can effectively affect the thermoelectric properties of materials, were investigated with XRD, Raman spectra, SEM mapping, and HR-TEM analysis.

Using Markers of Left Ventricular Filling Pressure to Predict Mortality in Mild to Moderate Aortic Stenosis: Insights from the National Echo Database of Australia (NEDA)

Background: Echocardiographic measures of elevated left ventricular filling pressure (LVFP) predict a worse prognosis in many conditions. We hypothesised that they would reflect the haemodynamic consequences of aortic stenosis (AS) and be useful in predicting survival in this setting. The current study tested this in patients with mild-moderate AS. Objective: To determine the relationship between acute (ratio of early transmitral flow to mitral annular velocities; E/E’) and chronic (indexed left atrial volume; LAVI) markers of LVFP and mortality in mild-moderate AS. Method: Retrospective analysis of data from the National Echo Database of Australia. The first record for patients >18 years showing mild-moderate AS (mean gradient 10–40 mmHg) or no AS (<10 mmHg) was included. Data on sex, age, examination date and death were also recorded. Results: 134,500 patients were included; 53% male, mean age 63 years, mean follow-up 4.6 years, 25,929 (19%) mild-moderate AS and 108,571 (81%) no AS. The hazard ratio (HR) for mortality in mild-moderate versus no AS was 1.11 (95% CI 1.08–1.13), adjusted for age and sex. In mild-moderate AS, LAVI >34 ml/m2 (HR = 1.96) and E/E’ >14 (HR = 2.15) were associated with an increased risk of death and remained independently predictive of survival (LAVI >34 HR = 1.26 and E/E’ HR = 1.45) in a multivariate model that also included age, sex and LV ejection fraction. Conclusion: Our data confirm higher mortality associated with mild-moderate AS compared to no AS. Indices of LVFP independently predict death in this group and may be useful in risk-stratifying patients prior to developing severe AS.

Isoflurane Anesthesia Masks Elevated Filling Pressures in Hypertensive Rats with Diastolic Dysfunction and Preserved Ejection Fraction: Comparison to Ketamine/Xylaxine Sedation

Introduction: Elevated left ventricular (LV) end-diastolic pressures (EDP) carry important prognostic value in patients with cardiomyopathies. Echocardiographic tools permit the non-invasive evaluation of EDP, however, in the laboratory they may be confounded by the need for sedation. In particular, inhaled agents have potent vascular effects which may mask changes in EDP. This study assessed the cardiovascular effects of isoflurane (ISO) and Ketamine/Xylazine (KX) sedation in rats with elevated EDP.