Left ventricular torsional mechanics after left ventricular reconstruction surgery for ischemic cardiomyopathy

Local electromechanical alterations determine the left ventricle rotational dynamics in CRT-eligible heart failure patients

Left ventricle, LV wringing wall motion relies on physiological muscle fiber orientation, fibrotic status, and electromechanics (EM). The loss of proper EM activation can lead to rigid-body-type (RBT) LV rotation, which is associated with advanced heart failure (HF) and challenges in resynchronization. To describe the EM coupling and scar tissue burden with respect to rotational patterns observed on the LV in patients with ischemic heart failure with reduced ejection fraction (HFrEF) left bundle branch block (LBBB). Thirty patients with HFrEF/LBBB underwent EM analysis of the left ventricle using an invasive electro-mechanical catheter mapping system (NOGA XP, Biosense Webster). The following parameters were evaluated: rotation angle; rotation velocity; unipolar/bipolar voltage; local activation time, LAT; local electro-mechanical delay, LEMD; total electro-mechanical delay, TEMD. Patients underwent late-gadolinium enhancement cMRI when possible. The different LV rotation pattern served as sole parameter for patients’ grouping into two categories: wringing rotation (Group A, n = 6) and RBT rotation (Group B, n = 24). All parameters were aggregated into a nine segment, three sector and whole LV models, and compared at multiple scales. Segmental statistical analysis in Group B revealed significant inhomogeneities, across the LV, regarding voltage level, scar burdening, and LEMD changes: correlation analysis showed correspondently a loss of synchronization between electrical (LAT) and mechanical activation (TEMD). On contrary, Group A (relatively low number of patients) did not present significant differences in LEMD across LV segments, therefore electrical (LAT) and mechanical (TEMD) activation were well synchronized. Fibrosis burden was in general associated with areas of low voltage. The rotational behavior of LV in HF/LBBB patients is determined by the local alteration of EM coupling. These findings serve as a strong basic groundwork for a hypothesis that EM analysis may predict CRT response.

Clinical trial registration: SUM No. KNW/0022/KB1/17/15.

Ventricular systolic dysfunction with and without altered myocardial contractility: Clinical value of echocardiography for diagnosis and therapeutic decision-making

The inability of one of the two or both ventricles to contract normally and expel sufficient blood to meet the functional demands of the body results from a complex interplay between intrinsic abnormalities and extracardiac factors that limit ventricular pump function and is a major cause for heart failure (HF). Even if impaired myocardial contractile function was the primary cause for ventricular dysfunction, with the progression of systolic dysfunction, additionally developed diastolic dysfunction can also contribute to the severity of HF. Although at the first sight, the diagnosis of systolic HF appears quite easy because it is usually defined by reduction of the ejection fraction (EF), in reality this issue is far more complex because ventricular pumping performance depends not only on myocardial contractility, but also largely on loading conditions (preload and afterload), being also influenced by valvular function, ventricular interdependence, pericardial constraint, synchrony of ventricular contrac-tion and heart rhythm. Conventional echocardiography (ECHO) combined with new imaging techniques such as tissue Doppler and tissue tracking can detect early subclinical alteration of ventricular systolic function. However, no single ECHO parameter reveals alone the whole picture of systolic dysfunction. Multiparametric ECHO evaluation and the use of integrative approaches using ECHO-parameter combinations which include also the ventricular loading conditions appeared particularly useful especially for differentiation between primary (myocardial damage-induced) and secondary (hemodynamic overload-induced) systolic dysfunction. This review summarizes the available evidence on the usefulness and limitations of comprehensive evaluation of LV and RV systolic function by using all the currently available ECHO techniques.

The Memory of the Heart

The embryological development of the heart is one of the most fascinating phenomena in nature and so is its final structure and function. The various ontogenetic passages form the evolutive basis of the final configuration of the heart. Each key step can be recognized in the final features, as the heart maintains a kind of “memory” of these passages. We can identify the major lines of development of the heart and trace these lines up to the mature organ. The aim of this review is to identify these key parameters of cardiac structure and function as essential elements of the heart’s proper functioning and bases for its treatment. We aim to track key steps of heart development to identify what it “remembers” and maintains in its final form as positively selected. A new vision based on the whole acquired knowledge must guide an in-depth scientific approach in future papers and guidelines on the topic and a complete, farsighted therapeutic conduct able to ensure the physiological correction of cardiac pathologies. The application of this modern, functional vision of the heart could improve the clinical treatment of heart disease, filling the gaps still present.

Tailoring therapy for ischemic cardiomyopathy: is Laplace's law enough?

The burden of heart failure has long plagued the productive years of the population, with therapeutic advances in the timely treatment of ischemic heart disease decreasing its associated mortality. Angiotensin-converting enzyme inhibitors and β-blockers have impacted heart failure therapeutics in a revolutionary way. The importance of blockade of the renin-angiotensin system and adrenergic stimulation are fully accepted concepts that apply in young and old, symptomatic and asymptomatic, borderline low and very low Ejection Fraction (EF), left ventricular failure and biventricular failure. Despite several interventions, both pharmaceutical and device based for the treatment of ensuing heart failure, the incidence is increasing in large proportions. Newer molecules like sacubitril show more promise. Despite these novel therapies, several patients relentlessly progress to a stage of advanced heart failure. The use of left-ventricular-assist devices has variable clinical benefit, with some patients progressing to heart transplantation.

Improvements in left ventricular twist mechanics following myectomy for hypertrophic cardiomyopathy with mid-ventricular obstruction

We aimed to evaluate left ventricle twist mechanics in mid-ventricular obstructive and apical type of hypertrophic cardiomyopathy and changes induced by myectomy. We studied 3 consecutive patients by cardiac magnetic resonance preoperatively and 6 weeks after myectomy. We calculated the apical and basal rotations at the base and apex respectively. All 3 patients underwent myectomy by the standard described technique. The basal rotations remained the same, while there was an improvement in the maximal apical rotation from 0.385 ± 0.3975° to 0.9086 ± 1.1751°. In hypertrophic cardiomyopathy with mid-ventricular obstruction and apical hypertrophy, there is decreased apical rotation, which improves after myectomy.

Improvements in Left Ventricular Diastolic Mechanics After Parachute Device Implantation in Patients With Ischemia Heart Failure: A Cardiac Computerized Tomographic Study

BACKGROUND

Percutaneous ventricular restoration therapy with the use of a left ventricle (LV)-partitioning Parachute device has emerged as a clinical treatment option for LV apical aneurysm after extensive anterior myocardial infarction (AMI). We assessed changes of diastolic mechanics and functional improvements following LV Parachute device implantation by means of cardiac computerized tomography (CCT).

METHODS AND RESULTS

CCT data were obtained from 28 patients before and after LV Parachute device implantation. Diastolic functional indices were determined by means of quantitative CCT assessment: 1) transmitral velocities in early (E) and late (A) diastole and ratio (E/A); 2) early diastolic mitral septal tissue velocity (Ea) and E/Ea; and 3) vortex formation time (VFT). Functional improvements were assessed with the use of New York Heart Association (NYHA) functional classification. Among the study patients, there were no significant differences in all transmitral velocities and E/A, though there was significantly increased Ea, reduced E/Ea, and greater VFT 6 months after LV Parachute device implantation. Finally, the improvement of diastolic functional indices after Parachute treatment correlated with observed clinical functional alterations (Δ E/Ea and Δ NYHA functional class:, r = 0.563; P = .002; Δ VFT and Δ NYHA functional class: r = -0.507; P = .006).

CONCLUSIONS

LV Parachute device implantation therapy in heart failure caused by AMI and LV apical aneurysm formation showed improvements in several diastolic functional mechanics according to CCT-based measures.

Left ventricular twist mechanics in the context of normal physiology and cardiovascular disease: a review of studies using speckle tracking echocardiography

The anatomy of the adult human left ventricle (LV) is the result of its complex interaction with its environment. From the fetal to the neonatal to the adult form, the human LV undergoes an anatomical transformation that finally results in the most complex of the four cardiac chambers. In its adult form, the human LV consists of two muscular helixes that surround the midventricular circumferential layer of muscle fibers. Contraction of these endocardial and epicardial helixes results in a twisting motion that is thought to minimize the transmural stress of the LV muscle. In the healthy myocardium, the LV twist response to stimuli that alter preload, afterload, or contractility has been described and is deemed relatively consistent and predictable. Conversely, the LV twist response in patient populations appears to be a little more variable and less predictable, yet it has revealed important insight into the effect of cardiovascular disease on LV mechanical function. This review discusses important methodological aspects of assessing LV twist and evaluates the LV twist responses to the main physiological and pathophysiological states. It is concluded that correct assessment of LV twist mechanics holds significant potential to advance our understanding of LV function in human health and cardiovascular disease.

Time series analysis of physiologic left ventricular reconstruction in ischemic cardiomyopathy

OBJECTIVE

The history of left ventricular reconstruction has demonstrated that the full spectrum of recoverable physiologic parameters is essential for a good functional result. We report the long-term outcome of a new surgical technique that arranges myocardial fibers in a near-normal disposition, also recovering left ventricular twisting.

METHODS

Between May 2006 and October 2013, 29 consecutive patients with previous anterior myocardial infarction and heart failure symptoms underwent physiologic left ventricular reconstruction surgery and coronary revascularization. Patients were examined by means of standard echocardiography and 2-dimensional speckle tracking at 8 time steps until 7 years after surgery. Ten geometric and functional parameters were evaluated at each step and analyzed by the linear mixed model test.

RESULTS

Hospital mortality was 0%. The mean percentage of indexed end-diastolic and end-systolic volume reduction was 45.7% and 50.9%, respectively. Ejection fraction and all of the volumes were significantly different in the postoperative period with a steady correction during time. Diastolic parameters were not worsened by surgical reconstruction. Ejection fraction and deceleration time showed a significant improvement during time. Left ventricular torsion increased immediately after the surgical correction from 2.8 ± 4.4 degrees to 8.7 ± 3.9 degrees (P = .02) and was still present 4 years after surgery.

CONCLUSIONS

Surgical conduction of ventricular reconstruction should be standardized to achieve the full spectrum of recoverable physiologic parameters. The renewal of ventricular torsion should be pursued as an adjunctive element of ventricular efficiency, mainly in ventricles that work at a critical level in the Frank-Starling relationship and pressure-volume loop.

Role of left ventricular twist mechanics in cardiomyopathies, dance of the helices

Left ventricular twist is an essential part of left ventricular function. Nevertheless, knowledge is limited in “the cardiology community” as it comes to twist mechanics. Fortunately the development of speckle tracking echocardiography, allowing accurate, reproducible and rapid bedside assessment of left ventricular twist, has boosted the interest in this important mechanical aspect of left ventricular deformation. Although the fundamental physiological role of left ventricular twist is undisputable, the clinical relevance of assessment of left ventricular twist in cardiomyopathies still needs to be established. The fact remains; analysis of left ventricular twist mechanics has already provided substantial pathophysiological understanding on a comprehensive variety of cardiomyopathies. It has become clear that increased left ventricular twist in for example hypertrophic cardiomyopathy may be an early sign of subendocardial (microvascular) dysfunction. Furthermore, decreased left ventricular twist may be caused by left ventricular dilatation or an extensive myocardial scar. Finally, the detection of left ventricular rigid body rotation in noncompaction cardiomyopathy may provide an indispensible method to objectively confirm this difficult diagnosis. All this endorses the value of left ventricular twist in the field of cardiomyopathies and may further encourage the implementation of left ventricular twist parameters in the “diagnostic toolbox” for cardiomyopathies.

Early feasibility evaluation of thoracoscopically assisted transcatheter ventricular reconstruction in an experimental model of ischaemic heart failure with left anteroapical aneurysm

AIMS

To test the feasibility of a thoracoscopically assisted, off-pump, transcatheter ventricular reconstruction (TCVR) approach in an ovine model of left ventricular (LV) anteroapical aneurysm.

METHODS AND RESULTS

Myocardial infarction (MI) was induced by coil occlusion of the middle left anterior descending artery and diagonals. Two months after MI creation, TCVR was performed via a minimal thoracotomy in eight sheep. Under endoscopic and fluoroscopic guidance, trans-interventricular septal puncture was performed from the LV epicardial scar. A guidewire was externalised via a snare placed in the right ventricle from the external jugular vein. An internal anchor was inserted over the wire and positioned on the right ventricular septum and an external anchor was deployed on the LV anterior epicardium. Serial pairs of anchors were placed and plicated together to exclude the scar completely. Immediately after TCVR, echocardiography showed LV end-systolic volume decreased from pre-procedure 58.8±16.6 ml to 25.1±7.6 ml (p<0.01) and the ejection fraction increased from 32.0±7.3% to 52.0±7.5% (p<0.01). LV twist significantly improved (3.83±2.21 vs. pre-procedure -0.41±0.94, p=0.01) and the global peak-systolic longitudinal strain increased from -5.64% to -10.77% (p<0.05).

CONCLUSIONS

TCVR using minimally invasive access techniques on the off-pump beating heart is feasible and resulted in significant improvement in LV performance.

Noncontact quantitative biomechanical characterization of cardiac muscle using shear wave imaging optical coherence tomography

We report on a quantitative optical elastographic method based on shear wave imaging optical coherence tomography (SWI-OCT) for biomechanical characterization of cardiac muscle through noncontact elasticity measurement. The SWI-OCT system employs a focused air-puff device for localized loading of the cardiac muscle and utilizes phase-sensitive OCT to monitor the induced tissue deformation. Phase information from the optical interferometry is used to reconstruct 2-D depth-resolved shear wave propagation inside the muscle tissue. Cross-correlation of the displacement profiles at various spatial locations in the propagation direction is applied to measure the group velocity of the shear waves, based on which the Young's modulus of tissue is quantified. The quantitative feature and measurement accuracy of this method is demonstrated from the experiments on tissue-mimicking phantoms with the verification using uniaxial compression test. The experiments are performed on ex vivo cardiac muscle tissue from mice with normal and genetically altered myocardium. Our results indicate this optical elastographic technique is useful as a noncontact tool to assist the cardiac muscle studies.

Characterization of dysfunctional remote myocardium in left ventricular anterior aneurysms and improvements following surgical ventricular restoration using cardiac magnetic resonance imaging: preliminary results

OBJECTIVES

In patients with previous myocardial infarction, the remote uninfarcted regions, although contractile, demonstrate dysfunctional wall kinetics because of increased afterload, which improves after surgical ventricular restoration (SVR). We characterized left ventricular (LV) mean myocardial velocity (MMV) through an analysis of endocardial motion and wall thickening (WT) over the cardiac cycle using standard cardiac magnetic resonance (cMR).

METHODS

LV endocardial motion and WT from cMR data in 7 heart failure (HF) patients with postinfarction antero apical aneurysm were compared against normal controls to establish a baseline for the mean myocardial velocity during phases of the cardiac cycle. The HF patients' MMV and WT curves were compared with post-SVR data.

RESULTS

Global MMV showed significant postoperative improvements in the ejection phase of systole and the early filling phase of diastole. The aneurysmal wall was dyskinetic in both systole and diastole. The remote myocardium preoperatively had a delayed peak velocity during the ejection phase of systole and diminished velocity during early filling in diastole. After SVR, the remote myocardium had an increased MMV with an earlier peaking during the ejection phase and slightly improved early diastolic velocity. WT increased cumulatively during systole and decreased during diastole with improved end-systolic and end-diastolic wall thickness after SVR. The end-systolic wall thickness showed a significant correlation with left ventricular ejection fraction (r(2) = 0.89, P = 0.001) and stroke volume (r(2) = 0.80, P = 0.02). The MMV had a significant correlation with WT over the phases of the cardiac cycle (r(2) = 0.953, P ≤ 0.0001).

CONCLUSIONS

In patients with chronic ischaemic heart disease with LV aneurysms/large areas of scar, improvements in the remote myocardial MMV and WT underline LV systolic function improvements after SVR. The persistence of myocardial WT in early diastole is the likely mechanism for incomplete or absence of relief of LV diastolic dysfunction by SVR.

Restoration of optimal left ventricular apical geometry and rotation following surgical ventricular restoration using rectangular patch plasty technique: a pilot study using cardiac magnetic resonance

OBJECTIVES

Clinical outcomes of surgical ventricular restoration (SVR) have been confirmed by Registry data. Accurate assessment of left ventricular (LV) morphology and function can help optimize these outcomes.

METHODS

LV remodelling in 7 patients (NYHA class 3 ± 1.2) with post-myocardial infarction LV aneurysms was characterized by the regional LV volume (RLVV) computed by dividing the LV in cine steady-state free precession cardiac magnetic resonance imaging (CMR) at each slice level into six radial segments. Rotation of the LV apex and base was analysed using tagged CMR. The apical conicity ratio was used to characterize the restored apical geometry.

RESULTS

The mean end-diastolic volume (EDV) was 174.8 ± 100.3 ml and the mean ejection fraction (EF) was 18.8 ± 7.8%. Following SVR, all patients had significant clinical improvements (NYHA Class I), and significant increases in the left ventricular ejection fraction (LVEF) to 38.8 ± 4.4%. The LV volumes and regional volumes at the base and apex decreased with a trend towards significance. The mean preoperative apical conicity ratio (ACR) was 1.90 ± 0.43 and, following SVR by endoventricular linear patch plasty (EVLPP), was 1.35 ± 0.3 (P = 0.02). The percent decrease in the ACR following SVR from baseline was 28.68 ± 10.98%. The apical EF increased from 1.19 ± 13.9 to 15.8 ± 8.2% (P = 0.028). The basal rotations improved from 3.13 ± 2.1 to 4.69 ± 2.94° (P = 0.04). The apical rotations also improved significantly from 2.48 ± 1.23 to 3.93 ± 2.45° (P = 0.05) and reversed to the normal anticlockwise direction.

CONCLUSIONS

SVR by geometric repair using a rectangular intracavitary patch helps restoration of a physiological apex with normalization of apical rotation reflecting a near-physiological LV function.

Automated motion estimation for 2-D cine DENSE MRI

Cine displacement encoding with stimulated echoes (DENSE) is a magnetic resonance (MR) method that directly encodes tissue displacement into MR phase images. This technique has successfully interrogated many forms of tissue motion, but is most commonly used to evaluate cardiac mechanics. Currently, motion analysis from cine DENSE images requires manually delineated anatomical structures. An automated analysis would improve measurement throughput, simplify data interpretation, and potentially access important physiological information during the MR exam. In this paper, we present the first fully automated solution for the estimation of tissue motion and strain from 2-D cine DENSE data. Results using both simulated and human cardiac cine DENSE data indicate good agreement between the automated algorithm and the standard semi-manual analysis method.

Evaluation of left ventricular torsion by cardiovascular magnetic resonance

Recently there has been considerable interest in LV torsion and its relationship with symptomatic and pre-symptomatic disease processes. Torsion gives useful additional information about myocardial tissue performance in both systolic and diastolic function. CMR assessment of LV torsion is simply and efficiently performed. However, there is currently a wide variation in the reporting of torsional motion and the procedures used for its calculation. For example, torsion has been presented as twist (degrees), twist per length (degrees/mm), shear angle (degrees), and shear strain (dimensionless). This paper reviews current clinical applications and shows how torsion can give insights into LV mechanics and the influence of LV geometry and myocyte fiber architecture on cardiac function. Finally, it provides recommendations for CMR measurement protocols, attempts to stimulate standardization of torsion calculation, and suggests areas of useful future research.

Heart disease and left ventricular rotation - a systematic review and quantitative summary

Background

Left ventricular (LV) rotation is increasingly examined in those with heart disease. The available evidence measuring LV rotation in those with heart diseases has not been systematically reviewed.

Methods

To review systematically the evidence measuring LV rotational changes in various heart diseases compared to healthy controls, literature searches were conducted for appropriate articles using several electronic databases (e.g., MEDLINE, EMBASE). All randomized-controlled trials, prospective cohort and case–controlled studies that assessed LV rotation in relation to various heart conditions were included. Three independent reviewers evaluated each investigation’s quality using validated scales. Results were tabulated and levels of evidence assigned.

Results

A total of 1,782 studies were found through the systematic literature search. Upon review of the articles, 47 were included. The articles were separated into those investigating changes in LV rotation in participants with: aortic stenosis, myocardial infarction, hypertrophic cardiomyopathy, dilated cardiomyopathy, non-compaction, restrictive cardiomyopathy/ constrictive pericarditis, heart failure, diastolic dysfunction, heart transplant, implanted pacemaker, coronary artery disease and cardiovascular disease risk factors. Evidence showing changes in LV rotation due to various types of heart disease was supported by evidence with limited to moderate methodological quality.

Conclusions

Despite a relatively low quality and volume of evidence, the literature consistently shows that heart disease leads to marked changes in LV rotation, while rotational systolic-diastolic coupling is preserved. No prognostic information exists on the potential value of rotational measures of LV function. The literature suggests that measures of LV rotation may aid in diagnosing subclinical aortic stenosis and diastolic dysfunction.

Load independence of two-dimensional speckle-tracking-derived left ventricular twist and apex-to-base rotation delay in nonischemic dilated cardiomyopathy: implications for left ventricular dyssynchrony assessment

BACKGROUND

Left ventricular (LV) twist mechanics are a promising, sensitive tool for assessing pathophysiologic changes in patients with systolic heart failure. Although LV twist is known to be load dependent in healthy volunteers, this has not been examined in patients with "long-standing" dilated cardiomyopathy (DCM). The aim of this study was to determine whether LV twist remains load dependent in the setting of long-standing, nonischemic DCM.

METHODS

Thirty-four patients with DCM with baseline LV ejection fractions (LVEFs) < 40% and 13 subjects with preserved LVEFs (≥50%) were enrolled. After baseline measurements, pneumatic compression of the lower extremities (Pcom) was used to increase LV afterload. Subsequently, sublingual nitroglycerin (SL-NG) was administered to modify preload. Conventional echocardiographic parameters, LV end-systolic wall stress, net LV twist angle, and apex-to-base-rotation delay (ABRD) were assessed under each condition.

RESULTS

In patients with DCM, although LV end-systolic wall stress significantly increased under Pcom (196.9 ± 64.9 g/m(2) at baseline vs 231.8 ± 78.9 g/m(2) under Pcom, P < .017) and decreased after SL-NG application (231.8 ± 78.9 g/m(2) under Pcom vs 197.4 ± 67.4 g/m(2) after SL-NG, P < .017), net LV twist angle and ABRD showed no significant changes depending on LV loading condition (for LV twist, 7.63 ± 4.47° at baseline vs 7.03 ± 4.13° under Pcom vs 7.35 ± 4.36° after SL-NG, P = 0.65; for ABRD, 16.56 ± 13.81% at baseline vs 17.19 ± 14.81% under Pcom vs 15.95 ± 13.27% after SL-NG, P = .53). Careful examination of individual patient data revealed that LV twist was load independent when patients had LV twist < 12°. ABRD was also found to be load independent, but only in patients with LVEFs < 34%. In contrast, LV twist and ABRD were load dependent in patients with preserved LVEFs.

CONCLUSIONS

LV twist and its component, ABRD, had relatively load insensitive properties in patients with long-standing DCM and can be used in future clinical trials as load-independent indexes of LV dyssynchrony.

Imaging three-dimensional myocardial mechanics using navigator-gated volumetric spiral cine DENSE MRI

A navigator-gated 3D spiral cine displacement encoding with stimulated echoes (DENSE) pulse sequence for imaging 3D myocardial mechanics was developed. In addition, previously described 2D postprocessing algorithms including phase unwrapping, tissue tracking, and strain tensor calculation for the left ventricle (LV) were extended to 3D. These 3D methods were evaluated in five healthy volunteers, using 2D cine DENSE and historical 3D myocardial tagging as reference standards. With an average scan time of 20.5 ± 5.7 min, 3D data sets with a matrix size of 128 × 128 × 22, voxel size of 2.8 × 2.8 × 5.0 mm(3), and temporal resolution of 32 msec were obtained with displacement encoding in three orthogonal directions. Mean values for end-systolic mid-ventricular mid-wall radial, circumferential, and longitudinal strain were 0.33 ± 0.10, -0.17 ± 0.02, and -0.16 ± 0.02, respectively. Transmural strain gradients were detected in the radial and circumferential directions, reflecting high spatial resolution. Good agreement by linear correlation and Bland-Altman analysis was achieved when comparing normal strains measured by 2D and 3D cine DENSE. Also, the 3D strains, twist, and torsion results obtained by 3D cine DENSE were in good agreement with historical values measured by 3D myocardial tagging.

'Let's twist again': surgically induced renewal of left ventricular torsion in ischemic cardiomyopathy

OBJECTIVES

To test the potential of the heart to be surgically restored at a near-normal global condition, granted that its physiological characteristics are respected (working volumes, chamber geometry, fiber orientation, opposite rotation of apex and base, global torsion and strain).

METHODS

From May 2007 to December 2008, 12 consecutive patients with ischemic cardiomyopathy were included in this study. All patients underwent modified surgical anterior ventricular restoration combined with complete coronary revascularization and, when indicated, mitral anuloplasty. The modified restoration aims to re-approach residual myocardium, redirecting fiber orientation displaced by infarct scar toward a more physiological gross disposition. Patients were studied preoperatively and postoperatively with a complete echocardiographical assessment, including speckle-tracking analysis.

RESULTS

Standard parameters significantly improved after the operation (end diastolic volume, P < 0.001; end systolic volume, P < 0.001; ejection fraction, P = 0.004), and so did peak systolic apical rotation, peak systolic left ventricular torsion and two-chamber and four-chamber longitudinal strain (P = 0.004, 0.003, 0.05 and 0.01, respectively). Pearson's correlation between apical rotation and longitudinal strain (two-chamber and four-chamber) was -0.877 (P < 0.001) and -0.720 (P = 0.008), respectively, and between torsion and longitudinal strain was -0.845 (P = 0.001) and -0.785 (P = 0.002), respectively.

CONCLUSION

This study reveals an unexpected potential of the myocardium to be restored at a near-normal global condition, with regard to all of its physiological characteristics. The concept of fiber-based surgical treatment, supported by an imaging-guided preoperative study, could widen the potential of repairing a failing heart.

Short-term systolic and diastolic ventricular performance after surgical ventricular restoration for dilated ischemic cardiomyopathy

OBJECTIVE

Based on the adverse relationship between left ventricular (LV) remodeling and clinical outcome in ischemic cardiomyopathy, surgical ventricular restoration (SVR) is proposed as a valuable adjunct procedure. This study reports on the short-term clinical and hemodynamical performance of SVR.

METHODS

Using end-systolic LV volume as indication for SVR, 78 patients with ischemic cardiomyopathy are divided in two groups: group 1 comprised 55 patients treated by coronary revascularization and mitral annuloplasty, group 2 comprised 23 patients undergoing additional SVR. Hemodynamic investigation included echocardiographic assessment of systolic and diastolic function. Clinical follow-up focused on survival and functional status with exercise performance.

RESULTS

Both surgical approaches resulted in improvement of NYHA class (2.9-1.6 in group 1; 3.3-1.5 in group 2, p<0.001), achieving similar exercise performance (peak VO2 13.7 vs 15.4 ml/kgmin in groups 1 and 2, p=0.25) and plasma BNP values (group 1: 1350 pg/ml and group 2: 767 pg/ml, p=0.23). SVR provided additional benefit as patients basically had a worse NYHA class (2.9 in group 1 vs 3.3 in group 2, p=0.03). Within mean follow-up of 20 months, survival rate was 84% in group 1 and 74% in group 2 (p=0.11), including operative mortality of 7% and 13% (p=0.42). Through effective volume reduction (LVEDVI 41%; LVESVI 49%) systolic function improved immediately after SVR (LVEF 27-39% in group 2, p<0.05). Worsening of diastolic function was specifically observed after SVR within the first year (E/A-ratio 1.38-1.74 cm/s, p=0.02). Recurrent mitral regurgitation (p=0.004) and secondary remodeling (p=0.01) were major determinants of decreasing LV compliance. Clinical outcome in terms of cardiac events and survival was compromised by restrictive diastolic function (p=0.02) and increased LV volumes (p=0.04).

CONCLUSION

SVR in addition to coronary revascularization and restrictive mitral annuloplasty results in significant clinical improvement in selected patients with advanced ischemic heart disease and severely dilated ventricles. SVR entails immediate improvement of systolic function, which remains sustained during short-term follow-up. Serial assessment of diastolic function is mandatory as LV compliance seems more sensitive to early changes induced by recurrence of mitral regurgitation and secondary ventricular dilation. Moreover, worsening of diastolic dysfunction should be timely recognized because of its adverse clinical impact.