Left Ventricular Stroke Volume Index Research Articles

Correlation between twofold left ventricular outflow tract-velocity time integral and stroke volume index in mechanicaly ventilated patients

Ultrasound is a non-invasive and bedside accessible method of cardiac function monitoring. Cardiac echocardiography has several limitations due to difficulties to obtain an acceptable acoustic window in critical care settings. Left ventricular outflow tract (LVOT) velocity time integral (VTI) can be measured in most critical care patient and is an useful tool for this purpose. Calculations of cardiac output needing aortic valve area are strongly dependent on skills and observers [1]. We hypothesize that twofold LVOT-VTI is an accurate calculation of stroke volume index (SVI).

Variability of postural orthostatic tachycardia in patients with myalgic encephalomyelitis and orthostatic intolerance.

Central nervous system dysfunction with myalgic encephalomyelitis (ME) has been suggested as the main cause of chronic fatigue syndrome. Fluctuation of the symptom severity and hierarchy is a characteristic feature in ME patients. The characteristics of the sympathetic activation may differ between the "good days" and "bad days" in them. Twenty-four ME patients with orthostatic intolerance underwent a conventional 10-min active standing test and echocardiography both on a "good day" and a "bad day", defined according to the severity of their symptoms. The mean heart rate at rest was significantly higher on the "bad days" than on the "good days". During the standing test on a "bad day", 5 patients (21%) failed to maintain an upright posture for 10min, whereas on a "good day" all the 24 patients maintained it. Postural orthostatic tachycardia (POT) (increase in heart rate ≥30beats/min) or severe POT (heart rate ≥120beats/min) was observed on the "bad days" in 10 patients (43%) who did not suffer from the severe tachycardia on the "good days", suggesting the exaggerated sympathetic nervous activation. In contrast, POT did not occur or severe POT was attenuated on the "bad days" in 5 patients (21%) who developed POT or severe POT on the "good days", suggesting the impaired sympathetic activation. Echocardiography revealed significantly lower mean values of both the left ventricular end-diastolic diameter and stroke volume index on the "bad days" compared with the "good days". In conclusion, in ME patients with orthostatic intolerance, the exaggerated activation of the sympathetic nervous system while standing appears to switch to the impaired sympathetic activation after the system is loaded with the additional accentuated stimuli associated with the preload reduction.

3D-Transesophageal Echocardiography in Paradoxical Low-Flow, Low-Gradient Aortic Stenosis

Background: In paradoxical low-flow, low gradient (PLFLG) aortic stenosis, 2D-transthoracic echocardiography (2D-TTE)may underestimate flow because it assumes a circular left ventricular outflow tract (LVOT) shape. Three-dimensional transesophagealechocardiography (3D-TEE) is a better method to measure LVOT area.Objectives: The aim of this study was to evaluate left ventricular stroke volume index (SVi) by 2D-TTE and 3D-TEE in patientswith normal heart (NH) and with severe aortic stenosis (SAS) and to determine how many patients are categorized asPLFLG by 2D-TTE and 3D-TEE.Methods: Thirty-five patients were evaluated by 2D-TEE and 3D-TEE: NH=17 patients and SAS=18 patients. Left ventricularoutflow tract area was estimated during early systole by 2D-TTE (ES2DLVOT Ar) and by 3D-TEE (ES3DLVOT Ar)planimetry, and as systolic average (Avg 3DLVOT Ar). Each LVOT area was multiplied by its corresponding flow integral toobtain SVi (ES2D-TTE SVi, ES3D-TEE SVi and Avg 3D-TEE SVi) in NH and SAS groups. Paradoxical LFLG was determinedin SAS following standard criterion.Results: NH: ES2DLVOT Ar vs. ES3DLVOT Ar p<0.05; SAS: ES2DLVOT Ar vs. ES3DLVOT Ar p<0.001 and vs. Avg 3DLVOTAr p<0.023; ES2D-TTE SVi vs. ES3D-TEE SVi p<0.002 and vs. Avg 3D-TEE SVi p<0.038. In the NH group, the lower limitof normal SVi for 2D-TTE, ES3D-TEE and Avg 3D-TEE was <34, <38.9 and <35.9 ml/m2, respectively. Three SAS patientswere categorized as PLFLG by 2D-TTE, but none by 3D-TEE.Conclusions: Patients with PLFLG by 2D-TTE could

Low-Flow, Low-Gradient Severe Aortic Stenosis in the Setting of Constrictive Pericarditis: Clinical Characteristics, Echocardiographic Features, and Outcomes.

Low-flow, low-gradient aortic stenosis (AS), associated with a poor prognosis, can be caused by a reduced stroke volume despite a preserved ejection fraction (left ventricular ejection fraction). We hypothesized that impaired ventricular diastolic filling secondary to constrictive pericarditis (CP) could contribute to reduced transaortic gradients in patients with AS+CP. We sought to examine the characteristics and outcomes of this unique cohort. We analyzed 84 patients with different degrees of AS and preserved left ventricular ejection fraction (≥50%): 28 diagnosed with concomitant CP by echocardiography and 56 patients without CP matched by age, sex, and AS severity during 1998 to 2013. Prior mediastinal radiation (32.1% versus 5.4%; P=0.0072) and cardiac surgery (50.0% versus 3.6%; P=0.0016) were more common in AS+CP patients than those with AS only. AS+CP patients had lower left ventricular stroke volume index and mean transaortic gradients. Five-year survival was 34.3% for AS+CP patients and 89.1% for those with AS only (P<0.001). In univariate analysis, prior mediastinal radiation (hazard ratio, 8.35; 95% confidence interval, 3.38-20.62; P<0.001), reduced left ventricular stroke volume index of <35 mL/m(2) (hazard ratio, 12.52; 95% confidence interval, 3.97-39.48; P<0.001), and concomitant CP (hazard ratio, 13.65; 95% confidence interval, 4.85-38.41; P<0.001) were highly associated with increased mortality. Our findings highlighted the possibility of CP as a pathophysiological mechanism for low-flow, low-gradient AS. Left ventricular stroke volume index and transaortic gradients were commonly reduced in AS in the setting of CP despite a preserved left ventricular ejection fraction, which may result in underestimation of AS severity. Prior mediastinal radiation, lower left ventricular stroke volume index, and concomitant CP were associated with poorer survival in AS patients.

Outcomes of surgical aortic valve replacement for severe aortic stenosis: Incorporation of left ventricular systolic function and stroke volume index

ObjectivesWe sought to assess predictors of mortality in consecutive patients with severe aortic stenosis undergoing aortic valve replacement and to determine whether there are differences in mortality, separated on the basis of different aortic stenosis subtypes and left ventricular stroke volume index. MethodsWe studied 875 patients (aged 69 ± 12 years, 67% were men) with severe aortic stenosis (aortic valve area ≤1 cm2) who underwent aortic valve replacement between January 2007 and December 2008 (excluding other severe valve disease, balloon aortic valvuloplasty, and transcatheter aortic valve replacement). Clinical and echocardiographic data were recorded. Left ventricular stroke volume index was measured as left ventricular outflow tract velocity time integral × left ventricular outflow tract area/body surface area. Patients were classified into the following subtypes: (1) standard severe (n = 536, left ventricular ejection fraction ≥50% and mean gradient ≥40 mm Hg); (2) paradoxic severe (n = 152, left ventricular ejection fraction ≥50%, mean gradient <40 mm Hg and left ventricular stroke volume index <35 mL/m2); and (3) low left ventricular ejection fraction severe (n = 187, ejection fraction <50%). Society of Thoracic Surgeons score and all-cause mortality were recorded. ResultsAt 4.8 ± 2 years, 153 patients (18%) died (30-day mortality 1.8%). On multivariable Cox analysis, age (hazard ratio [HR], 1.49), New York Heart Association class (HR, 1.52), prior cardiac surgery (HR, 1.41), aortic stenosis subtypes (standard severe reference HR, 1; paradoxic severe HR, 1.48; and low left ventricular ejection fraction severe HR, 2.03), and reduced glomerular filtration rate (HR, 1.17) were associated with higher long-term mortality (P < .05). ConclusionsIn patients with severe aortic stenosis undergoing aortic valve replacement, patients with standard severe aortic stenosis had better long-term survival than those with paradoxic severe or low left ventricular ejection fraction severe aortic stenosis.

EARLY IMPROVEMENT IN FLOW (LEFT VENTRICULAR STROKE VOLUME INDEX) AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT IS ASSOCIATED WITH IMPROVED SURVIVAL IN LOW-FLOW AORTIC STENOSIS

Low-flow (LF) severe aortic stenosis (AS) is an independent predictor of mortality in patients undergoing aortic valve replacement (AVR). We hypothesized that improvement in flow (left ventricular stroke volume index (SVI)) after transcatheter AVR (TAVR) would predict better clinical outcomes. All

Comparison of different interdialytic intervals among hemodialysis patients on their echocardiogram-based cardiovascular parameters

Although cardiovascular events in hemodialysis (HD) patients are the most frequent on the day after a long (2 days) interdialytic interval (IDT), it has been uncertain whether accumulation or elimination of large extracellular fluid volume, electrolyte, and/or uremic substances is the culprit for this. We sought to test our hypothesis that the long IDT alters echocardiographic parameters at rest and during exercise in stable maintenance HD patients compared with other IDTs. We performed a cross-sectional comparison using 1-way repeated analysis of variance or Friedman test of echocardiograms at 3 different IDTs, just after HD, after short IDT (1 day), and after long IDT, among 80 stable Japanese outpatients (age 61 ± 9 years, 60 males) on thrice weekly maintenance. End-systolic elastance (Ees), arterial elastance (Ea), and pressure-volume area (PVA) were estimated using a noninvasive single-beat technique. Ventricular-arterial coupling was assessed by Ea/Ees ratio. Measurements were repeated after 2-minute handgrip stress to evaluate cardiac reserve. Resting left ventricular end-diastolic volume index and stroke volume index were significantly larger after a 1-day IDT compared with just after HD and even more after a 2-day IDT. Although Ees, Ea, and Ea/Ees ratio at rest remained similar between short and long intervals, stroke work (SW) and PVA were higher after the long interval. During handgrip stress, a significant increase in Ea without corresponding rise in Ees was observed only after long IDT, resulting in decreased stroke volume index, SW, and SW/PVA efficiency. In a selective Japanese outpatient population on maintenance HD, there were no differences in resting cardiovascular function measured by echocardiography at 3 different IDTs. However, exercise-induced afterload mismatch assessed by the changes in Ea, SV, SW, and SW/PVA efficiency was most pronounced in individuals after the long IDT compared with other IDTs. Our findings report potential pathophysiologic echocardiographic parameters that attempt to explain why cardiovascular events are highest on the day after the long IDT compared to other IDTs in dialysis patients.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Abstract 20128: Effect of Renin-angiotensin Blockers on Left Ventricular Remodelling in Severe Aortic Stenosis

Background: The use of renin-angiotensin blockers (RAB: angiotensin converting enzyme inhibitors, ACEI and angiotensin receptor blockers, ARB) in severe aortic valve stenosis (AS) remains controversial. We aim to explore the relation on their use with degree of left ventricular (LV) remodelling in patients with normal flow (NF) and low-flow (LF) severe AS despite preserved LV ejection fraction (LVEF). Methods: We studied 423 consecutive patients with aortic valve area (AVA) 50%. Subjects with concomitant valvular pathologies, congenital heart disease or prosthetic valves were excluded. NF was categorized as LV stroke volume index (SVi) &gt; 35ml/m2. Increased left ventricular mass index (LVMI) was ≥96g/m2 and 116g/m2 in females and males respectively while abnormal relative wall thickness (RWT) was ≥0.45. Results: The median age was 74 yrs (IQR: 65-82). Prevalence of male subjects 52%, diabetes mellitus 61%, dyslipidemia 48% and hypertension 43%. A quarter of the patients were on RAB, with a mean duration of 6.7 months(IQR:1.0-72.3). Median LVMI for patients on RAB was 94.5 g/m2 (IQR: 87.3-144), whilst those without was 120.3 g/m2 (IQR: 102-159) (p=0.005). RAB use in patients with LF AS was significantly associated with normal LVMI, adjusted for hypertension (OR 2.00, p=0.002). The use of RAB had a duration dependent association with normal LVMI. Patients on RAB for a year were twice more likely to have normal LVMI (OR 2.24, p=0.048). This effect is greater in patients with 2 years of therapy (OR 3.417, p=0.002). In contrast, the use of RAB was not associated with normal LVMI in the NF group (p=0.428). There was no significant difference between use of either ACEI or ARB on LVMI (p=0.855). Patients on RAB had less risk of having concentric hypertrophy (OR= 0.373, p=0.009) and eccentric hypertrophy (0.392, p=0.025) as compared to those without. Conclusion: Use of RAB in LF severe AS may be associated with beneficial remodeling of the LV especially if prescribed for more than a year. Further studies are warranted to determine the deferential effects of RAB on clinical outcomes in LF versus NF AS.

Abstract 11741: Severe Aortic Stenosis With Normal Left Ventricular Ejection Fraction, Normal Flow and Low Gradients. Another Paradox or Only Moderate Stenosis?

Background: Among the 4 hemodynamic subsets of severe AS with preserved EF, based on LV stroke volume index (SVi) and mean pressure gradients, normal flow with a low gradient (NF/LG) has been attributed to measurement errors, small body size or inconsistencies in guideline criteria and associated with a favorable prognosis. We hypothesized that AV weight (AVW) in NF/LG AS, would be lower than that in other hemodynamic groups. Methods: Between 2010-13, 403 consecutive patients (pts) undergoing AV replacement (AVR) for severe isolated AS, (mean age 76.8 (9.3) yrs, 56% men, AVA index 0.36 (0.10 cm2)/m2, EF = 61.3 ± 4.6%, 11% bicuspid valves, mean follow-up 18 ± 9 months), underwent intraoperative TEE and had the AV weighed after excision (AVW = 2.4 ± 0.9 g), and excised valves were collected in formaldehyde, dried and weighed. All echo variables were measured off-line by a single observer on a dedicated reading station (Agfa). Medical records were reviewed to extract clinical data and all-cause mortality determined from the Social Security Death Index. Analysis of covariance (ANCOVA), Chi-square test, and Cox proportional hazards regression models were used as appropriate. Results: (for unadjusted comparisons see table.) In models adjusted for age, gender BSA, EF and annular area, AVW and AVW index remained lower in NF/LG than that in the high gradient groups (p&lt;.01 for both). Although the number of deaths was small, no significant difference in all-cause mortality or time from AVR to death was found among the 4 groups (p=0.27 and p=0.28, respectively). AVR improved survival to a similar degree regardless of hemodynamic phenotype. Conclusions: 1. Compared with high gradient groups, pts with normal flow-low gradient have a lower AVW and AVW/aortic annulus area, a lower severity of stenosis and less LV remodeling. 2. These findings support the recent recommendation to categorize these pts as having only moderate AS.

Abstract 12459: Is Ejection Fraction &lt;50% the Optimal Threshold for Referral for Valve Replacement in Patients With Severe Aortic Stenosis? Impact of Ejection Fraction on Post-Operative Outcome

Introduction: In asymptomatic patients with severe aortic stenosis (SAS), left ventricular (LV) ejection fraction (EF) &lt;50% is generally considered to be the threshold for referral for aortic valve replacement (AVR). Hypothesis: We investigated the importance of LVEF on long-term outcome after AVR in symptomatic and asymptomatic SAS patients and studied whether LVEF &lt; 50% is the optimal threshold for referral for AVR. Methods and Results: We retrospectively identified 2017 patients with SAS (aortic valve area (AVA)&lt;1cm2, mean aortic valve gradient ≥40 mm Hg, or indexed AVA &lt;0.6 cm2/m2) who underwent surgical AVR from January 1995 to June 2009 at our institution. Patients were divided into 4 groups depending on preoperative LVEF (&lt;50% in 300 (15%) patients, 50-59% in 331 (17%), 60-69% in 908 (45%), and ≥70% in 478 (24%)). The primary end-point was all-cause mortality. During follow-up of 5.3±4.4 years, 1056 (52%) died. Five-year mortality rate increased with decreasing LVEF (41% (n=106), LVEF&lt;50%); 35% (n=98), LVEF 50-59%; 26% (n=192), LVEF 60-69%; 22% (n=90), LVEF≥70%, p&lt;0.0001). Compared to patients with LVEF≥60%, patients with LVEF 50-59% had increased mortality (HR 1.58, p&lt;0.001), with a similar risk increase in both symptomatic (HR=1.56, p&lt;0.001) and asymptomatic patients (HR 1.58, p=0.006, Figure). In a Cox regression analysis corrected for standard risk factors, LV mass index, AVA, and stroke volume index, LVEF was predictive of all-cause mortality (HR=0.89 per 10%, p&lt;0.001). When this multivariable analysis was repeated in the subset of 1333 patients with no history of coronary artery disease, LVEF was still associated with all-cause mortality (HR=0.90 per 10%, p=0.009). Conclusion: In patients with SAS undergoing AVR, patients with LVEF 50-59% have also increased mortality compared to patients with LVEF&gt;60%, suggesting that a different LVEF threshold should be used when referring for AVR.

Prognostic value of echocardiographic and Doppler parameters in horses admitted for colic complicated by systemic inflammatory response syndrome

To assess the prognostic value of echocardiographic parameters of left ventricular (LV) function in horses with systemic inflammatory response syndrome (SIRS). Prospective observational study. Veterinary teaching hospital. Forty-one horses admitted for colic with clinical evidence of SIRS. All horses underwent Doppler echocardiographic examination on admission. LV echocardiographic parameters, including pulsed-wave tissue Doppler imaging parameters, were compared between nonsurvivors (n = 29) and horses that survived to discharge (n = 12). With comparable heart rate and LV preload estimate, LV stroke volume index, the velocity time integral, deceleration time, ejection time of Doppler aortic flow, and peak early diastolic myocardial velocity were lower in the nonsurviving than in the surviving horses, while pre-ejection period to ejection time ratio (PEP/ET) of Doppler aortic flow and the peak early diastolic filling velocity to peak early diastolic myocardial velocity ratio (E/Em) were higher (P < 0.05). A cut-off value of 0.26 for PEP/ET predicted mortality with 100% sensitivity and 42% specificity (area under the receiver operating characteristic curve: 0.71), whereas a cut-off value of 2.67 for E/Em predicted mortality with 100% sensitivity and 83% specificity (area under the receiver operating characteristic curve: 0.89). Echocardiography may provide prognostic information in colic horses with clinical evidence of SIRS. Especially, PEP/ET and E/Em could be useful markers of systolic and diastolic dysfunction, respectively, to detect horses with a high risk of death requiring more intensive cardiovascular monitoring as it has been reported in human patients with septic shock.

Clinical studies of surviving sepsis bundles according to PiCCO on septic shock patients

To explore the effect of early goal-directed therapy (EGDT) according to pulse indicated continuous cardiac output (PiCCO) on septic shock patients. Eighty-two septic shock patients in Subei People's Hospital of Jiangsu Province from January 2009 to December 2012 were enrolled and randomly divided into two groups using a random number table, standard surviving sepsis bundle group (n=40) and modified surviving sepsis bundles group (n=42). The patients received the standard EGDT bundles in standard surviving sepsis bundle group. PiCCO catheter was placed in modified surviving sepsis bundles group. Fluid resuscitation was guided by intrathoracic blood volume index (ITBVI) with the aim of 850-1 000 mL/m(2). Dobutamine was used to improve the heart function according to left ventricular contractile index (dPmax) and stroke volume index (SVI). The mean arterial blood pressure (MAP) was maintained 65 mmHg (1 mmHg=0.133 kPa) or above with norepinephrine. Extra-vascular lung water was monitored for the titration of liquid and diuretics. The acute physiology and chronic health evaluation II (APACHEII) score, sequential organ failure assessment (SOFA) score, the number of patients needed vasopressor, serum procalcitonin (PCT), lactic acid and lactate extraction ratio, the amount of fluid resuscitation, duration of mechanical ventilation, duration of intensive care unit (ICU) stay, hospital mortality were recorded in both groups. After treatment, the APACHEII score, SOFA score and the number of patients needed vasopressor were gradually reduced in both groups, and those in modified surviving sepsis bundle group were significantly lower than those of standard sepsis bundle group at 72 hours (APACHEII score: 13.1±6.5 vs. 20.9±7.5, SOFA score: 8.8±4.3 vs. 14.6±4.9, the number of patients needed vasopressor: 8 vs. 17, all P<0.05). Arterial blood lactate clearance rate was gradually increased after treatment in both groups. Lactate clearance rate in modified surviving sepsis bundle group was significantly higher than that of standard surviving sepsis bundle group [6 hours: (18.2±8.3)% vs. (10.8±7.5)%, t=-6.036, P=0.001; 12 hours: (22.6±7.3)% vs. (12.4±8.1)%, t=-4.536, P=0.001; 24 hours: (27.8±5.6)% vs. (16.4±9.5)%, t=-5.882, P=0.000]. The amount of fluid resuscitation within 6 hours in modified surviving sepsis bundle group increased significantly compared with standard surviving sepsis bundle group (3 608±715 mL vs. 2 809±795 mL, t=-3.865, P=0.033). The amount of fluid resuscitation within 24, 48 and 72 hours in modified surviving sepsis bundle group was significantly less than that of standard modified surviving sepsis bundle group with the nadir at 72 hours (918±351 mL vs. 1 805±420 mL, t=5.907, P=0.037). Duration of mechanical ventilation (98.4±20.3 hours vs. 143.3±29.6 hours, t=9.766, P=0.001) and ICU stay (7.1±3.1 days vs. 9.5±2.5 days, t=2.993, P=0.004) were significantly reduced in modified surviving sepsis bundle group compared with standard surviving sepsis bundle group. The hospital mortality in modified surviving sepsis bundle group was slightly lower than that in standard surviving sepsis bundle group [16.7% (7/42) vs. 17.5%(7/40), χ (2)=0.010, P=0.920]. Modified surviving sepsis bundle treatment according PiCCO can reduce the severity of disease in patients with septic shock, can make more accurately guide fluid resuscitation, and can reduce lung water and duration of mechanical ventilation and ICU stay. It has great clinical significance.

Long-Term Prognostic Value and Serial Changes of Plasma N-Terminal Prohormone B-Type Natriuretic Peptide in Patients Undergoing Transcatheter Aortic Valve Implantation

Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of N-terminal prohormone B-type natriuretic peptide (NT-proBNP) after TAVI, its related factors, and prognostic value. A total of 333 consecutive patients were included, and baseline, procedural, and follow-up (median 20 months, interquartile range 9 to 36) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1, 6, and 12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median 1,692 pg/ml); lower left ventricular ejection fraction and stroke volume index, greater left ventricular mass, and renal dysfunction were associated with greater baseline values (p <0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortalities (p <0.001 for both), with a baseline cut-off level of ∼2,000 pg/ml best predicting worse outcomes (p <0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (p <0.001) by 23% and remained stable up to 4-year follow-up. In 39% of the patients, however, there was a lack of NT-proBNP improvement, mainly related to preprocedural chronic atrial fibrillation, lower mean transaortic gradient, and moderate-to-severe mitral regurgitation (p <0.01 for all). In conclusion, most patients undergoing TAVI presented high NT-proBNP levels, and a lack of improvement was observed in >1/3 of the patients after TAVI. Also, higher NT-proBNP levels predicted greater overall and cardiac mortalities at a median follow-up of 2 years. These findings support the implementation of NT-proBNP measurements for the clinical decision-making process and follow-up of patients undergoing TAVI.

Abstract 19213: Long-Term Prognostic Value of and Serial Changes in Plasma N-terminal Pro B-type Natriuretic Peptide in Patients Undergoing Transcatheter Aortic Valve Implantation

Background: Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of NT-proBNP following TAVI, its related factors and prognostic value. Methods and Results: A total of 333 consecutive patients undergoing TAVI were included. Baseline, procedural and follow-up (median: 20 [8 to 35] months) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1-month, 6- to12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median: 1692 [667-3910] pg/mL); lower left ventricular ejection fraction and stroke volume index, higher LV mass, and renal dysfunction were associated with greater baseline values (p&lt;0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortality (P&lt;0.001 for both), with a baseline cut-off level of ~2,000 pg/mL best determining poorer outcomes (P&lt;0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (P&lt;0.001) by 23 (IQR: -62 to +32)% and remained stable up to 4-year follow-up. In 39% of the patients, however, NT-proBNP values increased to some degree. Pre-procedural chronic atrial fibrillation, lower mean transaortic gradient and moderate/severe mitral regurgitation were the predictors of the lack of NT-proBNP improvement after TAVI (P&lt;0.01 for all). Conclusions: Very high NT-proBNP levels were observed in most TAVI candidates, which in turn predicted a higher overall and cardiac mortality after a median follow-up of approximately 2 years. TAVI was associated with a significant decrease in NT-proBNP levels over time, but a lack of improvement was observed in more than one third of the patients, mainly due to the presence of chronic atrial fibrillation, a lower transvalvular gradient and moderate-to-severe mitral regurgitation. These results strongly suggest the usefulness of implementing NT-proBNP measurements for the clinical decision-making process and follow-up of TAVI patients.

Reproducibility and correlations of right ventricular end‐diastolic volume index measured by real‐time three‐dimensional echocardiography

To correlate right ventricular volumes measured by real-time three-dimensional echocardiography (RT3DE) with left ventricular volume indices in patients with or without left-sided heart diseases. For this retrospective, we reviewed 806 consecutive RT3DE examinations with quantitative evaluation of both the left and the right (RV) ventricle. We excluded cases of disease or surgery that would directly affect the size of the RV (eg, intracardiac shunt, significant tricuspid, or pulmonic regurgitation) as well as poor sonographic image quality, leaving a total of 701 studies for analysis. RV volumetric quantification was performed using dedicated software. Linear regression analysis showed that left ventricular stroke volume index significantly correlated with RV end-diastolic volume index (RVEDVI) (r = 0.78, p < 0.0001). Overall, 4% (28 of 701) of the patients had RVEDVI lower than 50 ml/m(2) , and 12% (84 of 701) had RVEDVI greater than 100 ml/m(2) . Intraclass correlation coefficient ranged from 0.91 to 0.99 for intraobserver and 0.85 to 0.98 for interobserver reproducibility. RT3DE was feasible and reproducible for quantifying RV volume. In patients without known primary RV pathology, RV volume strongly correlated with left ventricular stroke volume.

Effect of lifetime endurance training on left atrial mechanical function and on the risk of atrial fibrillation

Background: Left atrial (LA) dilation and prolongation of the signal-averaged P-wave duration (SAPWD) are linked to the amount and intensity of training. There is growing evidence that this atrial anatomical and electrical remodeling could be the substrate for the increased risk of atrial fibrillation (AF) observed in retrospective cohort studies of athletes. The aim of this study was to evaluate the impact of LA anatomical and electrical remodeling, in the context of lifetime exercise endurance training, on its passive (conduit) and active (pump) function measured by 2-D speckle tracking echocardiography (STE), and to find a link between LA functional adaptation and AF. Methods: Amateur male runners ≥30 years old were recruited (n=109) and, after exclusion of subjects having an office blood pressure >140/90mmHg or other cardiovascular risk factors, stratified in 3 groups according to lifetime training hours: low ( 4'500 h, n=30). Baseline examination consisted of an ECG with analysis of the SAPWD, Doppler echocardiography including STE, 24-hour ambulatory ECG and BP monitoring. Results: No differences were found, between the groups, in terms of age, BP, and diastolic function. LA maximal volume index (30±5, 33±5 vs. 37±6ml/m2, p<0.001), and conduit volume index (9±3, 11±3 vs. 12±3ml/m2, p<0.001) increased significantly from the low to the high training group, unlike the STE parameters which were comparable between the groups: strain pump -15.0±2.8, -14.7±2.7 vs. -14.9±2.6%, p=0.927; strain conduit 23.3±3.9, 22.1±5.3 vs. 23.7±5.7%, p=0.455. Independent predictors of LA strain conduit function were age, maximal early diastolic velocity of the mitral annulus, heart rate and peak early diastolic filling velocity. Left ventricular end diastolic volume index and stroke volume index both increased significantly with lifetime training hours. SAPWD (135±11, 139±10 vs. 148±14ms, p<0.001) and the number of premature atrial contractions (3 [1-7], 6 [2-12], 9 [3-26], p=0.008) increased from the low to the high training group. In one runner of the high training group 4 episodes of non-sustained AF were recorded. Conclusions: The LA anatomical and electrical remodeling does not have a negative impact on atrial mechanical function. LA enlargement may be an adaptation to volume overload, which permits a greater volume delivery to the simultaneously dilating left ventricle. A possible link between these risk factors for AF and its actual, rare occurrence in this athlete population, could not be uncovered in the present study.

Preserved ejection fraction can accompany low gradient severe aortic stenosis: impact of pathophysiology on diagnostic imaging

This editorial refers to ‘Differential left ventricular remodeling and longitudinal function distinguishes low-flow from normal-flow preserved ejection fraction low-gradient severe aortic stenosis’ by J.W. Hung et al ., doi:10.1093/eurheartj/eht094. Grading the severity of aortic stenosis (AS) on the basis of aortic valve area (AVA), mean pressure gradient, and left ventricular (LV) ejection fraction (EF) at rest and under stress was believed to be a straightforward matter, an approach also permitting discrimination between ‘classic’ low gradient/low output AS and pseudo-severe AS.1 If we are still accustomed to equate LVEF with systolic function, we need to ask if that is really permissible. In some patients with low gradient, findings remain incongruous, i.e. the LVEF is normal although significant AS is very likely.2 Aortic stenosis always begets LV remodelling mainly characterized by myocardial hypertrophy. In some individuals, however, the natural course of AS is accompanied by a degree of hypertrophy which exceeds a ‘certain’ level characterized by a relative wall thickness (RWT) of >50%, a phenomenon also known as ‘increased concentric remodelling’ (ICR). For a variety of reasons, including straightening of the cavity and decreased filling due to impaired diastolic LV function, ICR brings about a decrease in the end-diastolic volume (EDV). Therefore, a normal EF suggesting normal systolic LV function may be associated with a low LV stroke volume index (SVI) if …

Prognostic Significance of Cardiac Magnetic Resonance Imaging in Children With Pulmonary Hypertension

There are very few validated prognostic markers in pediatric pulmonary hypertension. Cardiac MRI is a useful, noninvasive method for determining prognosis in adults. The present study is the first to assess its prognostic value in children. A total of 100 children with pulmonary hypertension (median, 10.4 years; range, 0.5-17.6 years) were evaluated (idiopathic, n=60; repaired congenital heart disease, n=22; miscellaneous, n=18). In all patients, ventricular volumes and great vessel flow were measured. Volumetric data were obtained using retrospectively gated cine imaging (n=37) or real-time imaging (n=63), depending on the patient's ability to hold his or her breath. During a median follow-up of 1.9 years, 11 patients died and 3 received lung transplantation. Of the cardiac MR parameters measured, right ventricular ejection fraction and left ventricular stroke volume index were most strongly predictive of survival on univariate analysis (2.6- and 2.5-fold increase in mortality for every 1-SD decrease, respectively; P<0.05). These results were reflected in good separation of tertile-based Kaplan-Meier survival curves for these variables. Cardiac MR measures correlate with clinical status and prognosis in children with pulmonary hypertension. Cardiac MR is feasible and may be useful in clinical decision making in pediatric pulmonary hypertension.

Cardiovascular effects of 1 year of progressive endurance exercise training in patients with heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a disease of the elderly with cardiovascular stiffening and reduced exercise capacity. Exercise training appears to improve exercise capacity and cardiovascular function in heart failure with reduced ejection fraction. However, it is unclear whether exercise training could improve cardiovascular stiffness, exercise capacity, and ventricular-arterial coupling in HFpEF. Eleven HFpEF patients and 13 healthy controls underwent invasive measurements with right heart catheterization to define Starling and left ventricular (LV) pressure-volume curves; secondary functional outcomes included Doppler echocardiography, arterial stiffness, cardiopulmonary exercise testing with cardiac output measurement, and ventricular-arterial coupling assessed by the dynamic Starling mechanism. Seven of 11 HFpEF patients (74.9 ± 6 years; 3 men/4 women) completed 1 year of endurance training followed by repeat measurements. Pulmonary capillary wedge pressures and LV end-diastolic volumes were measured at baseline during decreased and increased cardiac filling. LV compliance was assessed by the slope of the pressure-volume curve. Beat-to-beat LV end-diastolic pressure (estimated from pulmonary arterial diastolic pressure) and stroke volume index were obtained, and spectral transfer function analysis was used to assess the dynamic Starling mechanism. Before training, HFpEF patients had reduced exercise capacity, distensibility and dynamic Starling mechanism but similar LV compliance and end-diastolic volumes compared to controls albeit with elevated filling pressure and increased wall stress. One year of training had little effect on LV compliance and volumes, arterial stiffness, exercise capacity or ventricular-arterial coupling. Contrary to our hypothesis, 1 year of endurance training failed to impart favorable effects on cardiovascular stiffness or function in HFpEF.