Pascal Lim

Impact of Longitudinal Myocardial Deformation on the Prognosis of Chronic Heart Failure Patients

Background—Longitudinal myocardial deformation indexes appear superior to left ventricular ejection fraction (LVEF) in assessing myocardial contractility. However, few studies have addressed the prognostic value of longitudinal motion markers (velocity, strain, and strain rate) in predicting outcome in heart failure patients. Methods and Results—The study included 125 consecutive symptomatic heart failure patients (63±16 years, 77% male, LVEF=31±10%). All patients underwent a complete echocardiographic and clinical examination, and brain natriuretic peptide level was assessed in 93 patients. Longitudinal myocardial velocity by tissue Doppler imaging, global-ϵ, and strain rate by speckle tracking were computed from apical views (4-, 3-, and 2-chambers views) and compared with the occurrence of major adverse cardiac events. On the whole, peak longitudinal velocity, global-ϵ, and strain rate averaged 5±2 cm/s (range, 1 to 9), −8±3% (range, −3 to −18), and −0.33±0.16 s−1 (range, −0.83 to −0.05), respectively. During the follow-up period (266±177 days), major adverse cardiac events occurred in 47 (38%) patients (15 deaths, 29 recurrent heart failure, and 4 heart transplantations). By univariable analysis using Cox model global-ϵ, strain rate, and LVEF were associated with the occurrence of major adverse cardiac events, whereas only global-ϵ remained independently predictive of outcome by multivariate analysis. Conclusions—In the heart failure population, longitudinal global strain by speckle tracking is superior to LVEF and other longitudinal markers in identifying patients with poor outcome.

Single-Beat Versus Multibeat Real-Time 3D Echocardiography for Assessing Left Ventricular Volumes and Ejection Fraction A Comparison Study With Cardiac Magnetic Resonance

Background—Real-time 3-dimensional echocardiography (RT3DE) is superior to 2D echocardiography in assessing left ventricular (LV) volumes and ejection fraction (EF), but its feasibility is limited by multibeat acquisition, which requires an optimal breath-hold and a regular heart rhythm. We sought to evaluate the accuracy and feasibility of single- and 2-beat RT3DE for LV volume and EF assessment. Methods and Results—Sixty-six consecutive patients referred for cardiac magnetic resonance (CMR) underwent RT3DE and CMR on the same day. Of the 50 patients (age, 59±18 years; 68% men; 42% coronary artery disease; LVEF=49±14%; limits, 14% to 76%) with an adequate RT3DE image quality, accuracy for LV volumes and EF measurements of single- and 2-beat modalities were compared with the conventional 4-beat acquisition and CMR. Correlations with CMR for LV end-diastolic volume (161±59 mL, r=0.93 to 0.94) and end-systolic volume (86±56 mL, r=0.93 to 0.96) were excellent regardless of the number of cardiac cycles used. However, because of the low temporal resolution (7±2 volumes per second), single-beat underestimated LVEF (bias, −5±8%) with greater bias than 2-beat (bias, 1±6%, P<0.001) and 4-beat (bias, 3±7%, P<0.001) modalities. Interestingly, 2-beat provided accuracy similar to 4-beat for end-diastolic volume (bias, −17±21 mL versus −15±23 mL), end-systolic volume (bias, −9±16 mL versus −12±17 mL), and LVEF (bias, 1±6% versus 3±7%) measurements, but fewer stitching artifacts were observed with 2- than 4-beat modalities (3% versus 30%). Conclusions—Compared with conventional multibeat acquisitions, 2-beat modality provides similar accuracy in LV volume and EF measurements and should be preferred due to fewer stitching artifacts. In contrast, the temporal resolution of single-beat modality appears insufficient to provide an accurate estimation of LVEF.

Comparison of real-time three-dimensional speckle tracking to magnetic resonance imaging in patients with coronary heart disease.

This study compared strain values from 2-dimensional (2D) and real-time 3-dimensional (3D) speckle tracking with hyperenhancement transmural extent by magnetic resonance imaging (MRI). The study included 18 control subjects (mean age 51 ± 10 years) and 25 patients (20 men, mean age 62 ± 16 years) with ischemic left ventricular (LV) dysfunction (mean LV ejection fraction 41 ± 9%) referred for viability assessment using MRI. Longitudinal, radial, and circumferential strain values were computed using 2D speckle tracking. From analysis of 3D speckle tracking, conventional strain markers (longitudinal, radial, and circumferential) and 2 new 3D strain indexes (area and 3D strains) were obtained from apical view 3D datasets. A hyperenhancement transmural extent segment (16-segment model) was defined as delayed contrast enhancement >50%. Overall, 661 of 688 segments (96%) were analyzable by MRI and 3D speckle tracking. All 3D strain components in hyperenhancement transmural extent segments (n = 154) were lower than in nontransmural necrosis (n = 219) and control (n = 288) segments. Longitudinal strain by 3D, but not by 2D, differentiated nontransmural segments with scar <25%. All 3D global strain indexes correlated with LV ejection fraction (r(2) = 0.67 to 0.26, p <0.05 for all comparisons), whereas only area, longitudinal, and circumferential 3D strains correlated with global scar extent. The best reproducibility was provided by 3D longitudinal (6%) and area (8%) strains. In conclusion, longitudinal and area strains by 3D speckle tracking provide an accurate and reproducible measurement of myocardial deformation that correlate with infarct size in patients with ischemic LV dysfunction.

Incremental value of global longitudinal strain for predicting early outcome after cardiac surgery

AIMS Global longitudinal strain (GLS) seems accurate for detecting subclinical myocardial dysfunction, and may therefore be used to improve risk stratification for cardiac surgery. METHODS AND RESULTS Longitudinal strain (by two-dimensional speckle tracking) was computed in 425 patients [mean age 67 ± 13 years, 69% male, left ventricular ejection fraction (LVEF) 51 ± 13%] referred for cardiac surgery [isolated coronary artery bypass graft (CABG) (n = 155), aortic valve surgery (n = 174), mitral surgery (n = 96)]. GLS (global-ε) was assessed for predicting early postoperative death. Despite a fair correlation between LVEF and global strain (r = -0.73, P < 0.0001), 40% of patients with preserved LVEF (defined as LVEF ≥50%) had abnormal global-ε (defined as global-ε >-16%): -12.8 ± 1.7%, range -15% to -8%. In patients with preserved LVEF, NT-proBNP level (983 vs. 541 pg/mL, P = 0.03), heart failure symptoms (NYHA class, 2.2 ± 0.9 vs. 1.9 ± 0.9, P = 0.02), and the need for prolonged (>48 h) inotropic support after surgery (33.3 vs. 21.2%, P = 0.03) were greater when global-ε was impaired. Importantly, despite similar EuroSCORE (9.7 ± 12 vs. 7.7 ± 9%, P = 0.2 for EuroSCORE I and 4.2 ± 6.2 vs. 3.4 ± 4.9%, P = 0.4 for EuroSCORE II), the rate of postoperative death was 2.4-fold (11.8 vs. 4.9%, P = 0.04) in patients with preserved LVEF when global-ε was impaired. Multivariate analysis showed that global-ε is an independent predictor for early postoperative mortality [odds ratio = 1.10 (1.01-1.21)] after adjustment to EuroSCORE. CONCLUSION GLS has an incremental value over LVEF for risk stratification in patients referred for cardiac surgery.

Multicentre study using strain delay index for predicting response to cardiac resynchronization therapy (MUSIC study).

Strain delay index (SDI) allows quantification of the wasted contraction or gain of myocardial contractility expected after cardiac resynchronization therapy (CRT). The present multicentre prospective study aimed to assess the accuracy of the SDI in predicting responses to CRT in real‐life patients with wide and narrow (<130 ms) QRS complexes.

Prognostic Value of Right Ventricular Two-Dimensional Global Strain in Patients Referred for Cardiac Surgery

BACKGROUND Right ventricular (RV) function is a strong predictor of patient outcome after cardiac surgery. Limited studies have compared the predictive value of RV global longitudinal strain (RV-GLS) with tricuspid annular plane systolic excursion (TAPSE) and RV fractional area change (RVFAC) in this setting. METHODS The study included 250 patients (66 ± 13 years old, LVEF = 52% ± 12%) referred for cardiac surgery (EuroSCORE-II = 4.8% ± 8.0%). RV function before surgery was assessed by RV-GLS by using speckle-tracking analysis (3-segment from the RV free wall), RVFAC and TAPSE was compared with postoperative outcome defined by 1-month mortality. RESULTS Overall, 19 patients (7.6%) had RVFAC < 35%, 34 (13.6%) had TAPSE < 16 mm, and 99 (39.6%) had impaired RV-GLS > -21% (35% with normal RVFAC ≥ 35%). Postoperative death (n = 25) was higher in patients with abnormal RV-GLS > -21% (22% vs 3%; P < .0001), TAPSE < 16 mm (24% vs 8%; P = .007), and RVFAC < 35% (32% vs 9%; P = .001). Mortality was 3% in patients with preserved RV-GLS. In patients with preserved RVFAC ≥ 35% but abnormal RV-GLS, mortality was similar to that of those with RVFAC < 35% (20% vs 32%; P = .12). Among RV systolic indexes, only RV-GLS was associated with patient outcome by multivariate analysis adjusted to EuroSCORE-II and cardiopulmonary bypass duration. CONCLUSIONS RV-GLS is a sensitive marker of RV dysfunction and correlates with postoperative mortality.

Patients without prolonged QRS after TAVI with CoreValve device do not experience high-degree atrio-ventricular block.

To identify clinical and electrical factors predicting delayed high‐degree atrio‐ventricular block (AVB) after transcatheter aortic valve implantation (TAVI).

Impact of acoustic window on accuracy of longitudinal global strain: a comparison study to cardiac magnetic resonance

AIMS To evaluate the impact of acoustic window on the feasibility and accuracy of longitudinal global strain (global-ε) by speckle tracking for assessing left ventricular (LV) systolic function. METHODS AND RESULTS The study included 70 patients (57 ± 17 years, 64% men), 28 selected patients with a suboptimal image quality (IQ) defined by three or more segments (4 ± 3 segments/patient) with wall motion score not analysable visually and 42 patients with an optimal two-dimensional (2D) echocardiography IQ. Left ventricular ejection fraction (LVEF) by Simpsons biplane method (2D-EF), global-ε by speckle tracking, and peak systolic mitral annulus velocity [systolic tissue Doppler imaging (S-TDI)] were compared with LVEF by cardiac magnetic resonance (EF-CMR; 45 ± 18%, range 9-76%). Speckle-tracking analysis was feasible in all segments with an optimal acoustic window and in 85% (103/121) of segments poorly visualized. Global-ε similarly correlated with LVEF by CMR in patients with and without optimal IQ (r = 0.81 vs. 0.82 for good vs. poor IQ). In contrast, 2D-EF (r = 0.76) and S-TDI (r = 0.64) less correlated with LVEF by CMR in patients with a suboptimal IQ. Importantly, IQ only impacted on 2D-EF inter-observer reproducibility (9 ± 5 vs. 24 ± 22% for good vs. poor IQ) but not on global-ε reproducibility (9 ± 1 vs. 8 ± 7% for good vs. poor IQ). CONCLUSION In patients with a limited acoustic window, longitudinal strain by speckle tracking remains accurate and reproducible for assessing global and regional LV systolic function.

Hemodynamic effects of Ivabradine in addition to dobutamine in patients with severe systolic dysfunction

BACKGROUND Dobutamine induced tachycardia increases myocardial oxygen consumption and impairs ventricular filling. We hypothesized that Ivabradine may be efficient to control dobutamine induced tachycardia. METHODS We assessed the effects of Ivabradine in addition to dobutamine in stable heart failure (HF) patients (LVEF < 35%, n = 22, test population) and validated its effects in refractory cardiogenic shock patients (n = 9, validation population) with contraindication to cardiac assistance or transplant. In the test population (62 ± 17 years, LVEF = 24 ± 8%), systolic and diastolic function were assessed at rest and under dobutamine [10 γ/min], before and after Ivabradine [5mg per os]. In the validation population (54 ± 11 years, LVEF = 22 ± 7%), Ivabradine [5mg twice a day] was added to the dobutamine infusion. RESULTS In the test population, Ivabradine decreased heart rate [HR] at rest and during dobutamine echocardiography (-9 ± 8 bpm, P = 0.0004). The decrease in HR was associated with a decrease in cardiac power output and an increase in diastolic duration at rest (+ 74 ± 67 ms, P = 0.0002), and during dobutamine infusion (+ 75 ± 67 ms, P < 0.0001). Change in LVEF during dobutamine was greater after Ivabradine treatment than before (+ 7.2 ± 4.7% vs. + 3.6 ± 4.2%, P = 0.002). In the validation population, Ivabradine decreased HR (-18 ± 11 bpm, P = 0.008) and improved diastolic filling time (+ 67 ± 42 ms, P = 0.012) without decreasing cardiac output. At 24h, Ivabradine improved systolic blood pressure (+ 9 ± 5 mmHg, P = 0.007), daily urine output (+ 0.7 ± 0.5L, P = 0.008), oxygen balance (ΔScv02 = + 13 ± 15%, P = 0.010), and NT-pro BNP (-2270 ± 1912 pg/mL, P = 0.017). Finally, only 2/9 (22%) patients died whereas expected mortality determined from a historical cohort was 78% (P = 0.017). CONCLUSION This pilot study demonstrates the safety and potential benefit of a HR lowering agent in cardiogenic shock.

Prognosis value of central venous oxygen saturation in acute decompensated heart failure

BACKGROUND Central venous oxygen saturation (ScvO2) provides an estimation of body oxygen consumption/delivery ratio. Its use has been suggested for monitoring treatment of patients admitted for acute decompensated heart failure (ADHF) but the optimal target value has never been clearly reported. AIMS We aimed to address the prognostic value of ScvO2 in ADHF requiring inotrope support. METHODS ScvO2 was prospectively assessed in 60 patients with ADHF requiring inotrope support (mean age 62±16 years; 45 men; left ventricular ejection fraction 25±7%) and was compared with major adverse cardiac events (MACE), defined as heart transplantation, cardiac assistance and death. RESULTS MACE occurred in 22 (35%) patients (14 deaths; eight referred for heart transplantation or cardiac assistance). Admission ScvO2 (mean 57±13%) did not differ between patients with and without MACE. At 24 hours ScvO2 (mean 62±7%) increased only in patients without MACE (65±6% vs. 58±7%; p<0.0001) and was associated with urine output, vena cava diameter and oxygen consumption reduction. No correlation was observed between ScvO2 and cardiac output or catecholamine rate. Multivariable analysis showed that ScvO2 at 24 hours remained an independent predictor of MACE. Using the optimal cut-off of 60% derived from receiver operating characteristic curves, MACE were observed in 81% of patients (17/21) with ScvO2≤60% at 24 hours vs. 13% (5/39) with ScvO2>60% at 24 hours. CONCLUSION In patients admitted for ADHF requiring inotrope support, ScvO2≤60% despite optimal treatment is a marker of poor outcome and might be an indicator for considering more aggressive therapy.