Impact of left atrial and diastolic ventricular dysfunction on mortality in patients with aortic stenosis

BACKGROUND

Diastolic dysfunction (DD) is common in severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF≥50%).

AIM

To determine the impact of American Society of Echocardiography/European Association of Cardiovascular Imaging-recommended DD grading and left atrial strain on mortality in a cohort of patients with severe AS and preserved LVEF.

METHODS

We studied patients with severe AS (aortic valve area indexed<0.6 cm²/m² and/or aortic valve area<1cm²), LVEF≥50% and no or mild AS-related symptoms. The endpoint was all-cause mortality.

RESULTS

A total of 387 patients (median age 76years; 53% women) were studied. During a median follow-up of 57 (interquartile range 37; 83) months, 158 patients died. After adjustment for prognostic factors, patients with grade II or III DD had an increased mortality risk versus patients with grade I DD (adjusted hazard ratio (aHR) 1.62, 95% confidence interval (CI) 1.11-2.38; P=0.013; aHR 4.73, 95% CI 2.49-8.99; P<0.001; respectively). Adding peak atrial longitudinal strain (PALS)≤14% to a multivariable model including DD grade improved predictive performance, with better global model fit, reclassification and discrimination. Patients with grade III DD or grade II DD+PALS≤14% displayed an increased mortality risk versus patients with grade I DD+PALS>14% (aHR 4.17, 95% CI 2.46-7.06; P<0.0001). Those with grade I DD+PALS≤14% or grade II DD+PALS>14% were at intermediate risk (aHR 1.63, 95% CI 1.07-2.49; P=0.024).

CONCLUSIONS

Our results demonstrate the strong relationship between DD and mortality in patients with severe AS and preserved LVEF. Patients with grade III or grade II DD and impaired PALS are at very high risk. These data demonstrate the importance of a comprehensive assessment of diastolic function in patients with severe AS.

Relationship Between the Ratio of Acceleration Time/Ejection Time and Mortality in Patients With High-Gradient Severe Aortic Stenosis

Background

The ratio of acceleration time/ejection time (AT/ET) is a simple and reproducible echocardiographic parameter that integrates aortic stenosis severity and its consequences on the left ventricle. No study has specifically assessed the prognostic impact of AT/ET on outcome in patients with high‐gradient severe aortic stenosis (SAS) and no or mild symptoms. We sought to evaluate the relationship between AT/ET and mortality and determine the best predictive AT/ET cutoff value in these patients.

Methods and Results

A total of 353 patients (median age, 79 years; 46% women) with high‐gradient (mean pressure gradient ≥40 mm Hg and/or aortic peak jet velocity ≥4 m/s) SAS, left ventricular ejection fraction ≥50%, and no or mild symptoms were studied. The impact of AT/ET ≤0.35 or >0.35 on all‐cause mortality was retrospectively studied. During a median follow‐up of 39 (25th–75th percentile, 23–62) months, 70 patients died. AT/ET >0.35 was associated with a considerable increased mortality risk after adjustment for established prognostic factors in SAS under medical and/or surgical management (adjusted hazard ratio [HR], 2.54; 95% CI, 1.47–4.37; P<0.001) or conservative management (adjusted HR, 3.29; 95% CI, 1.70–6.39; P<0.001). Moreover, AT/ET >0.35 improved the predictive performance of models including established risk factors in SAS with better global model fit, reclassification, and discrimination. After propensity matching, increased mortality risk persisted when AT/ET >0.35 (adjusted HR, 2.10; 95% CI, 1.12–3.90; P<0.001).

Conclusions

AT/ET >0.35 is a strong predictor of outcome in patients with SAS and no or only mild symptoms and identifies a subgroup of patients at higher risk of death who may derive benefit from earlier aortic valve replacement.

Clinical Significance of Global Wasted Work in Patients with Heart Failure Receiving Cardiac Resynchronization Therapy

BACKGROUND

The relationship between myocardial work assessment using pressure-strain loops by echocardiography before cardiac resynchronization therapy (CRT) and response to CRT has been recently revealed. Among myocardial work parameters, the impact of left ventricular myocardial global wasted work (GWW) on response to CRT and outcome following CRT has been seldom studied. Hence, the authors evaluated the relationship between preprocedural GWW and outcome in a large prospective cohort of patients with heart failure (HF) and reduced ejection fraction receiving CRT.

METHODS

The study included 249 patients with HF. Myocardial work indices including GWW were calculated using speckle-tracking strain two-dimensional echocardiography using pressure-strain loops. End points of the study were (1) response to CRT, defined as left ventricular reverse remodeling and/or absence of hospitalization for HF, and (2) all-cause death during follow-up.

RESULTS

Median follow-up duration was 48 months (interquartile range, 43-54 months). Median preoperative GWW was 281 mm Hg% (interquartile range, 184-388 mm Hg%). Preoperative GWW was associated with CRT response (area under the curve, 0.74; P < .0001), and a 200 mm Hg% threshold discriminated CRT nonresponders from responders with 85% specificity and 50% sensitivity, even after adjustment for known predictors of CRT response (adjusted odds ratio, 4.03; 95% CI, 1.91-8.68; P < .001). After adjustment for established predictors of outcome in patients with HF with reduced ejection fraction receiving CRT, GWW < 200 mm Hg% remained associated with a relative increased risk for all-cause death compared with GWW ≥ 200 mm Hg% (adjusted hazard ratio, 2.0; 95% CI, 1.1-3.9; P = .0245). Adding GWW to a baseline model including known predictors of outcome in CRT resulted in an improvement of this model (χ² to improve 4.85, P = .028). The relationship between GWW and CRT response and outcome was stronger in terms of size effect and statistical significance than for other myocardial work indices.

CONCLUSIONS

Low preoperative GWW (<200 mm Hg%) is associated with absence of CRT response in CRT candidates and with a relative increased risk for all-cause death. GWW appears to be a promising parameter to improve selection for CRT of patients with HF with reduced ejection fraction.

P908Prognostic value of energy loss index in patients with low gradient severe aortic stenosis and preserved ejection fraction

Background

Assessment of pressure recovery adjusted indexed aortic valve area (AVAi) – energy loss index (ELI) – has been shown of prognostic interest for patients with asymptomatic and/or mild aortic stenosis (AS), but limited data are available in the setting of low gradient aortic stenosis (LG-AS).

Purpose

We hypothesized that among these patients with LG-AS, reclassification of AS severity as moderate by ELI may help to identify a subgroup of patients with moderate AS.

Methods

379 patients with low gradient severe AS (defined by AVAi ≤0.6 cm2/m2 and mean aortic pressure gradient (MPG) <40 mmHg) and preserved left ventricular ejection fraction (LVEF ≥50%) were prospectively included. Reclassification as moderate AS by ELI was defined as AVAi ≤0.6 cm2 /m2 but an ELI >0.6 cm2/m2. Clinical and echocardiographic features of patients reclassified by ELI were studied. Clinical outcomes were all-cause and cardiac mortality.

Results

148 patients (39%) were reclassified as moderate AS by ELI. By multivariable logistic regression analysis, patients being reclassified as moderate AS by ELI were associated with increased stroke volume index (SVi), absence of documented coronary artery disease and decreased body surface area, left indexed ventricular mass (all p<0.05). During a median follow-up of 34 months (30–38 months), 119 patients died, 52 of them from cardiac causes. Three-year survival free from all-cause or cardiac death were 76±4%, 96±2% for patients with moderate AS by ELI and 71±3%, 84±3% for patients with severe AS by ELI (p=0.178 and p=0.013, respectively). After adjustment for variables of prognostic interest including aortic valve replacement as a time-dependent covariable, there was a significant reduction of risk of cardiac mortality in patients with moderate AS by ELI (adjusted HR 0.44 [95% CI, 0.23–0.85]; p=0.014) but not for all-cause mortality (adjusted HR 0.85 [95% CI, 0.58–1.25]; p=0.403)

Conclusion

In patients with low gradient “severe” AS and preserved ejection fraction, calculation of ELI permits to reclassify almost 40% of patients as having moderate AS. Patients reclassified as moderate AS by ELI had a reduction of risk of cardiac mortality during follow-up but not for all-cause mortality. Calculation of ELI may be useful for decision making in AS patients with discordant grading and preserved ejection fraction.

Acknowledgement/Funding

Local funding

Assessment of left ventricular size and function by 3-dimensional transthoracic echocardiography: Impact of the echocardiography platform and analysis software

BACKGROUND

Whether echocardiography platform and analysis software impact left ventricular (LV) volumes, ejection fraction (EF), and stroke volume (SV) by transthoracic tridimensional echocardiography (3DE) has not yet been assessed. Hence, our aim was to compare 3DE LV end-diastolic and end-systolic volumes (EDV and ESV), LVEF, and SV obtained with echocardiography platform from 2 different manufacturers.

METHODS

3DE was performed in 84 patients (65% of screened consecutive patients), with equipment from 2 different manufacturers, with subsequent off-line postprocessing to obtain parameters of LV function and size (Philips QLAB 3DQ and General Electric EchoPAC 4D autoLVQ). Twenty-five patients with clinical indication for cardiac magnetic resonance imaging served as a validation subgroup.

RESULTS

LVEDV and LVESV from 2 vendors were highly correlated (r = 0.93), but compared with 4D autoLVQ, the use of Qlab 3DQ resulted in lower LVEDV and LVESV (bias: 11 mL, limits of agreement: -25 to +47 and bias: 6 mL, limits of agreement: -22 to +34, respectively). The agreement between LVEF values of each software was poor (intraclass correlation coefficient 0.62) despite no or minimal bias. SVs were also lower with Qlab 3DQ advanced compared with 4D autoLVQ, and both were poorly correlated (r = 0.66). Consistently, the underestimation of LVEDV, LVESV, and SV by 3DE compared with cardiac magnetic resonance imaging was more pronounced with Philips QLAB 3DQ advanced than with 4D autoLVQ.

CONCLUSIONS

The echocardiography platform and analysis software significantly affect the values of LV parameters obtained by 3DE. Intervendor standardization and improvements in 3DE modalities are needed to broaden the use of LV parameters obtained by 3DE in clinical practice.

Is mechanical dyssynchrony a therapeutic target in heart failure with preserved ejection fraction?

BACKGROUND

Previous studies have found a high frequency of mechanical dyssynchrony in patients with heart failure (HF) with preserved ejection fraction (HFpEF), hence suggesting that cardiac resynchronization therapy (CRT) may be considered in HFpEF. The present study was designed to compare the amount of mechanical dyssynchrony between HFpEF patients and (1) HF with reduced EF (HFrEF) patients with an indication for CRT (HFrEF-CRT(+)) group, (2) HFrEF patients with QRS duration < 120 ms (HFrEF-QRS < 120 ms) group, and (3) hypertensive controls (HTN).

METHODS

Electrical (ECG) and mechanical dyssynchrony (atrio-ventricular dyssynchrony, interventricular dyssynchrony, intraventricular dyssynchrony) were assessed using conventional, tissue Doppler, and Speckle Tracking strain echocardiography in 40 HFpEF patients, 40 age- and sex-matched HTN controls, 40 HFrEF-QRS < 120 ms patients, and 40 HFrEF-CRT(+) patients.

RESULTS

The frequency of left bundle branch block was low in HFpEF patients (5%) and similar to HTN controls (5%, P = 0.85). Indices of dyssynchrony were similar between HFpEF and HTN patients or HFrEF-QRS < 120 ms patients. In contrast, most indices of dyssynchrony differed between HFpEF and HFrEF-CRT(+) patients. The principal components analysis on the entire cohort of 160 patients yielded 2 homogeneous groups of patients in terms of dyssynchrony, the first comprising HFrEF-CRT(+) patients and the second comprising HTN, HFrEF-QRS < 120 ms and HFpEF patients.

CONCLUSIONS

Mechanical dyssynchrony in HFpEF does not differ from that of patients with HTN or patients with HFrEF and a narrow QRS. This data raises concerns regarding the role of dyssynchrony in the pathophysiology of HFpEF and thereby the potential usage of CRT in HFpEF.

Echocardiographic prediction of postoperative atrial fibrillation after aortic valve replacement for aortic stenosis: a two-dimensional speckle tracking left ventricular longitudinal strain multicentre pilot study

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, with increased risk of embolic events, haemodynamic instability, haemorrhagic complications and prolonged hospital stay.

AIMS

We sought to assess the value of preoperative left ventricular global longitudinal strain (GLS) for the prediction of POAF in a series of patients with severe symptomatic aortic stenosis who underwent aortic valve replacement (AVR).

METHODS

Fifty-eight consecutive patients (52% men) aged 73±9 years, with severe symptomatic aortic stenosis (aortic valve area<1cm(2) or<0.5cm(2)/m(2)), in sinus rhythm, who underwent AVR were prospectively included in three centres between 2009 and 2010. Complete preoperative echocardiography was performed in all patients, including global and segmental longitudinal strain using two-dimensional speckle tracking.

RESULTS

The POAF incidence was 28/58 (48%). On univariate analysis, aortic valve area (P=0.04), preoperative E/e' ratio (P=0.04) and GLS (P=0.005) were associated with the occurrence of POAF. Chronic obstructive pulmonary disease (P=0.05), preoperative statin treatment (P=0.09), age≥80 years (P=0.09), left ventricular ejection fraction (P=0.09) and systolic pulmonary artery pressure (P=0.06) tended to increase the risk of POAF. The best GLS cut-off value for the prediction of POAF was -15% (82% sensitivity, 53% specificity, area under the curve 0.72). On multivariable analysis, GLS>-15% was the only independent predictor of POAF (odds ratio 7.74, 95% confidence interval [1.15-52.03]; P=0.035).

CONCLUSIONS

Incidence of POAF is high after AVR for severe aortic stenosis. Our results suggest an additive value of the study of left ventricular myocardial deformation to classical clinical and echocardiographic variables for the prediction of POAF in this setting.