Surgical ventricular restoration for the treatment of heart failure

CircMap4k2 Reactivated by Aneurysm Plication Alleviates Residual Cardiac Remodeling After SVR by Enhancing Cardiomyocyte Proliferation in Post-MI Mice

INTRODUCTION

Surgical ventricular reconstruction (SVR) is an alternative therapeutic approach in patients with refractory heart failure (HF), but residual remodeling after SVR limits the improvement of HF. Recently, we reported that SVR may act as an environmental cue to reactivate endogenous proliferation of cardiomyocytes; however, it is unclear whether enhancing endogenous cardiomyocyte regeneration further improves HF after SVR.

OBJECTIVES

We aimed to explore whether circular RNAs (circRNAs) would involved in SVR and their mechanisms.

METHODS

Male C57BL/6 mice were subjected to myocardial infarction (MI) or sham surgery. Four weeks later, MI mice with a large ventricular aneurysm underwent SVR or a second open-chest operation only. Echocardiography and histological analysis were used to evaluate heart function, cardiac remodeling, and myocardial regeneration. Sequencing of circular RNAs, RNA immunoprecipitation, RNA pulldown, and luciferase reporter assay were used to explore the underlying mechanisms.

RESULTS

SVR markedly attenuated cardiac remodeling and induced cardiomyocyte regeneration, as evidenced by positive staining of Ki-67, phospho-histone H3 (pH3), and Aurora B in the plication zone, but significant residual remodeling still existed in comparison with the sham group. Sequencing results showed that SVR altered the expression profile of cardiac circRNAs, and circMap4k2 was identified as the most upregulated one. After characterizing circMap4k2, we noted that overexpression of circMap4k2 significantly promoted proliferation of cardiomyocytes in cultured neonatal rat cardiomyocytes and silencing of circMap4k2 significantly inhibited it; similar results were obtained in SVR-treated MI mice but not in MI mice without SVR treatment. Residual cardiac remodeling after SVR was further attenuated by circMap4k2 overexpression. CircMap4k2 bound with miR-106a-3p and inhibited cardiomyocyte proliferation by targeting a downstream effector of the antizyme inhibitor 1 (Azin1) gene.

CONCLUSIONS

CircMap4k2 acts as an environmental cue and targets the miR-106a-3p/Azin1 pathway to increase cardiac regeneration in the plication zone and attenuate residual remodeling after SVR.

Surgical treatment of left ventricular aneurysm in patients with prior myocardial infarction in the absence of obstructive coronary artery disease (MINOCA): a cohort study

BACKGROUND

There is a paucity of studies examining the treatment of patients with prior myocardial infarction in the absence of obstructive coronary arteries (MINOCA) and with a concomitant left ventricular aneurysm. Our study aims to illustrate the clinical characteristics and report the mid-term surgical outcomes in this distinct entity.

METHODS

Ten patients with MINOCA and left ventricular aneurysm were investigated. The MINOCA was diagnosed according to Scientific Statement from the American Heart Association. The indication for left ventricular reconstruction was as follows: clear evidence of both an aneurysmal and akinetic left ventricle with a history of myocardial infarction accompanied by heart failure symptoms, angina, or ventricular arrhythmias. Major adverse cardiovascular and cerebrovascular events (MACCE), including death, myocardial infarction, stroke was considered the primary endpoints.

RESULTS

The median follow-up for the whole study population was 64.5 months. Seven MINOCA patients developed a left ventricular aneurysm within 4 years and three MINOCA patients were found to have a concomitant left aneurysm at the first admission. Before surgery, no patients were prescribed angiotensin-converting enzyme inhibitors. Statins, dual antiplatelet therapy, and β-blockers were prescribed in 2, 5, and 5 patients, respectively. After surgery, no MACCE occurred in the follow-up. There was a significant increase in ejection fraction (EF) in the follow-up (p = 0.0009).

CONCLUSIONS

Close monitoring and standard medical treatment are required before a left ventricular aneurysm occurs in MINOCA patients. Left ventricular reconstruction remains a viable option for MINOCA patients with left ventricular aneurysms and mid-term outcomes were satisfying in this distinct entity.

Transapical ventricular reshaping reduces functional mitral regurgitation and improves ventricular function in a preclinical model of ischemic cardiomyopathy

OBJECTIVE

A significant proportion of patients with advanced heart failure present with dilated left ventricles and functional mitral regurgitation. These patients currently have limited treatment options. The MitraClip device (Abbott) has benefited only patients with smaller left ventricles (end-diastolic dimension <70 mm), whereas those with larger left ventricles did not benefit. A possible explanation is correcting functional mitral regurgitation alone may not adequately reduce the wall stresses of a dilated left ventricle. We have developed a beating-heart device that not only approximates the papillary muscles to reduce functional mitral regurgitation but also modifies the left ventricle size and shape to reduce wall stress.

METHODS

Yorkshire swine (n = 16) had a myocardial infarction induced by permanent occlusion of the left circumflex with intracoronary ethanol. Three months later, the animals developed heart failure and moderate or greater functional mitral regurgitation. Through a transapical approach, the new device was implanted under echocardiography guidance to reshape the left ventricle and correct functional mitral regurgitation. The acute impact of this approach on the mitral valve and left ventricle was assessed with echocardiography and invasive hemodynamics.

RESULTS

After reshaping, echocardiography showed a decrease in end-diastolic volume by 36.3 ± 30.5 mL (P < .001), a decrease in sphericity index by 0.143 ± 0.087 (P < .001), and an increase in ejection fraction of 5.90% ± 6.38% (P < .01). Mitral valve tenting area was reduced by 39.29 ± 33.66 mm2 (P < .001), coaptation length was increased by 2.12 ± 1.02 mm (P < .001), and posterior excursion angle was improved by 9.07° ± 9.14° (P < .01), resulting in functional mitral regurgitation reduction.

CONCLUSIONS

Correction of functional mitral regurgitation with favorable changes in mitral valve geometry and reduction in left ventricle geometry is possible with the proposed device.

The Value of Stress-Gated Blood Pool SPECT in Predicting Early Postoperative Period Complications in Ischemic Cardiomyopathy Patients: Focus on Mechanical Dyssynchrony

(1) Objective: The objective of this study was to assess the prognostic value of stress-gated blood pool SPECT (GBPS) estimates in patients with ischemic cardiomyopathy (ICM) in the early postoperative period. (2) Methods: A total of 57 patients (age 59.7 ± 6.6, 47 men) with ICM and LV ejection fraction (30 [27.5; 35]%) were enrolled in the study. Before surgical treatment, all patients underwent GBPS (rest-stress, dobutamine doses of 5/10/15 µg/kg/min). Stress-induced changes in left ventricular (LV) ejection fraction, peak ejection rate, volumes, and mechanical dyssynchrony (phase histogram standard deviation, phase entropy (PE), and phase histogram bandwidth) were estimated. Two-dimensional transthoracic echocardiography was performed baseline. Serum levels of NT-proBNP were analyzed with enzyme-linked immunoassay. (3) Results: After surgical treatment, patients were divided into two groups, one, with death, the need for an intra-aortic balloon pump (IABP) or/and inotropic support with a stay in the intensive care unit for more than two days and two, without complications in the early postoperative period (EPOP). Complicated EPOP (CEPOP) was observed in 17 (30%) patients (death-2, IABP-4, extra inotropic support in intensive care unit-11), and 40 patients had no complications (NCEPOP). GBPS showed differences in LV EDV (mL) (321 [268; 358] vs. 268 [242; 313], p = 0.02), LV ESV (mL) (242 [201; 282] vs. 196 [170; 230], p = 0.005), and stress-induced changes in PE (1 (-2; 3) vs. -2 (-4; 0), p = 0.02). Aortic cross-clamp time and stress-induced changes in PE between rest and dobutamine dose of 10 µg/kg/min were the only independent predictors of CEPOP. An increase in LV entropy ≥ 1 on the dobutamine dose of 10µg/kg/min in comparison to rest investigation showed AUC = 0.853 (sensitivity = 62%, specificity = 90%, PPV = 71%; NPV = 85%; p < 0.0001). Conclusion: Stress-induced changes in PE obtained during low-dose dobutamine GBPS are associated with a complicated course of the early postoperative period after surgical treatment for ICM.

Transcatheter Left Ventricular Restoration in Patients With Heart Failure

BACKGROUND

Left ventricular (LV) volume reshaping reduces myocardial wall stress and may induce reverse remodeling in patients with heart failure with reduced ejection fraction. The AccuCinch Transcatheter Left Ventricular Restoration system consists of a series of anchors connected by a cable implanted along the LV base that is cinched to the basal free wall radius. We evaluated the echocardiographic and clinical outcomes following transcatheter left ventricular restoration.

METHODS AND RESULTS

We analyzed 51 heart failure patients with a left ventricular ejection fraction between 20% and 40%, with no more than 2+ mitral regurgitation treated with optimal medical therapy, who subsequently underwent transcatheter left ventricular restoration. Serial echocardiograms, Kansas City Cardiomyopathy Questionnaire scores, and 6-minute walk test distances were measured at baseline through 12 months. Primary analysis end point was change in end-diastolic volume at 12 months compared with baseline. Patients (n = 51) were predominantly male (86%) with a mean age of 56.3 ± 13.1 years. Fluoroscopy showed LV free wall radius decreased by a median of 9.2 mm amounting to a 29.6% decrease in the free wall arc length. At 12 months, the LV end-diastolic volume decreased by 33.6 ± 34.8 mL (P < .01), with comparable decreases in the LV end-systolic volume. These decreases were associated with significant improvements in the overall Kansas City Cardiomyopathy Questionnaire score (16.4 ± 18.7 points; P < .01) and 6-minute hall walk test distance (45.9 ± 83.9 m; P < .01). There were no periprocedural deaths; through the 1-year follow-up, 1 patient died (day 280) and 1 patient received a left ventricular assist device (day 13).

CONCLUSIONS

In patients with heart failure with reduced ejection fraction without significant mitral regurgitation receiving optimal medical therapy, the AccuCinch System resulted in decreases of LV volume, as well as improved quality of life and exercise endurance. A randomized trial is ongoing (NCT04331769).

Outcomes of continuous flow left ventricular assist device after surgical left ventricular restoration

OBJECTIVES

This study aimed to report the clinical outcomes of continuous flow left ventricular assist device implantation in end-stage chronic heart failure patients with a history of surgical left ventricular restoration.

METHODS

We retrospectively identified 190 patients undergoing continuous flow left ventricular assist device implantation at our center from November 2007 to April 2020. In total, six patients underwent continuous flow left ventricular assist device implantation after various types of surgical left ventricular restoration procedures, including endoventricular circular patch plasty (n = 3), posterior restoration procedure (n = 2), and septal anterior ventricular exclusion (n = 1).

RESULTS

Continuous flow left ventricular assist device (Jarvik 2000, n = 2; EVAHEART, n = 1; HeartMate II, n = 1; DuraHeart, n = 1; HVAD, n = 1) was successfully implanted in all patients. During a median follow-up of 48 months (interquartile range, 39-60 months; censoring heart transplantation), no death was documented, which means that overall survival after left ventricular assist device implantation was 100% at any time point. Finally, three patients received heart transplantation (waiting time: 39, 56, and 61 months, respectively) and the other three patients are still awaiting heart transplantation (waiting time: 12, 41, and 76 months, respectively).

CONCLUSIONS

In our series, continuous flow left ventricular assist device implantation after surgical left ventricular restoration was safe and feasible, even if an endoventricular patch was used, and effective for bridge to transplant strategy.

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Results of reconstructive interventions in patients with ischemic cardiomyopathy

BACKGROUND

Effective treatment of patients with ischemic cardiomyopathy is one of the most difficult issues in contemporary cardiac surgery. The aim of this study was to evaluate the long-term effectiveness of reconstructive interventions on the left ventricle during chronic heart failure in patients with ischemic cardiomyopathy.

METHODS

Between March 2013 and December 2017, 178 patients underwent surgical treatment for ischemic cardiomyopathy. Isolated coronary artery bypass grafting was compared with coronary artery bypass grafting with left ventricular reconstruction, using propensity score matching analysis. The primary endpoints of the study were hospital mortality and long-term survival.

RESULTS

After propensity score matching, 29 pairs of patients were compared. The 30-day hospital mortality was comparable (6.8% versus 6.8%, p = 0.952), the average follow-up was 37.4 ± 12.6 months, with no statistically significant difference in mortality from all causes (p = 0.352). After coronary artery bypass in combination with left ventricular reconstruction, patients showed a statistically significant decrease in clinical and functional indicators of chronic heart failure compared to those who had coronary artery bypass grafting alone, in terms of peak oxygen consumption (15.3 versus 13.5 mL·kg^-1·min^-1, p = 0.043) and N-terminal pro-brain natriuretic peptide concentrations (298.6 versus 461.1 pg·mL^-1, p = 0.032).

CONCLUSIONS

Compared to isolated coronary artery bypass, coronary artery bypass in combination with left ventricular reconstruction for the treatment of ischemic cardiomyopathy leads to a significant decrease in the clinical and functional parameters of chronic heart failure in the long-term postoperative period.

Non-heart transplant surgical approaches with mitral valve operation and surgical ventricular reconstruction for non-ischaemic dilated cardiomyopathy: a Japanese multicenter study

OBJECTIVES

There is uncertainty over the efficacy of additional surgical ventricular reconstruction (SVR) associated with mitral valve operation for non-ischaemic dilated cardiomyopathy (DCM). This study aims to assess mid-term outcomes of these non-heart transplant surgical approaches for DCM.

METHODS

We reviewed retrospectively 106 patients (median age 64, 44 females) who underwent isolated mitral annular plasty (MAP; n = 34), mitral valve replacement (MVR; n = 29), and SVR associated with MAP (SVR + MAP; n = 43) for DCM, in 11 Japanese hospitals. We analysed mid-term outcomes, specifically freedom from cardiac death and cardiac event.

RESULTS

Hospital deaths occurred in 16 patients (15.1%) and cardiac deaths in 36 patients (34.0%) during the study period of 4.4 ± 3.5 years. Freedom from cardiac death at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 79.1%, 82.6%, and 29.5% (P < 0.0001). Freedom from cardiac event at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 42.8%, 59.9%, 22.6% (P = 0.0004). In the multivariable analyses, preoperative tricuspid regurgitation (TR) grade was the only risk factor for both cardiac death and event, whereas MVR for DCM emerged as a protective factor for cardiac event.

CONCLUSIONS

This study could not show any benefit of additional SVR, by means of volume reduction, to MAP, because the baseline characteristics were different even after the stratification of DCM grade. MVR can be performed with favorable mid-term outcomes even in patients with advanced DCM, while patients undergoing MAP with/without SVR had more frequent MR recurrence or cardiac events. Interestingly, the right ventricular feature is a predictor of both cardiac death and events, with the TR grade being a predictor of poor mid-term outcomes.

Mitral regurgitation: anatomy is destiny

Mitral regurgitation (MR) occurs when any of the valve and ventricular mitral apparatus components are disturbed. As MR progresses, left ventricular remodelling occurs, ultimately causing heart failure when the enlarging left ventricle (LV) loses its conical shape and becomes globular. Heart failure and lethal ventricular arrhythmias may develop if the left ventricular end-systolic volume index exceeds 55 ml/m2. These adverse changes persist despite satisfactory correction of the annular component of MR. Our goal was to describe this process and summarize evolving interventions that reduce the volume of the left ventricle and rebuild its elliptical shape. This 'valve/ventricle' approach addresses the spherical ventricular culprit and offsets the limits of treating MR by correcting only its annular component.

What Is the Heart? Anatomy, Function, Pathophysiology, and Misconceptions

Cardiac dynamics are traditionally linked to a left ventricle, right ventricle, and septum morphology, a topography that differs from the heart's five-century-old anatomic description of containing a helix and circumferential wrap architectural configuration. Torrent Guasp's helical ventricular myocardial band (HVMB) defines this anatomy and its structure, and explains why the heart's six dynamic actions of narrowing, shortening, lengthening, widening, twisting, and uncoiling happen. The described structural findings will raise questions about deductions guiding "accepted cardiac mechanics", and their functional aspects will challenge and overturn them. These suppositions include the LV, RV, and septum description, timing of mitral valve opening, isovolumic relaxation period, reasons for torsion/twisting, untwisting, reasons for longitudinal and circumferential strain, echocardiographic sub segmentation, resynchronization, RV function dynamics, diastolic dysfunction's cause, and unrecognized septum impairment. Torrent Guasp's revolutionary contributions may alter future understanding of the diagnosis and treatment of cardiac disease.

Insights from Second-Line Treatments for Idiopathic Dilated Cardiomyopathy

Background: Dilated cardiomyopathy (DCM) is an independent nosographic entity characterized by left ventricular dilatation and contractile dysfunction leading to heart failure (HF). The idiopathic form of DCM (iDCM) occurs in the absence of coronaropathy or other known causes of DCM. Despite being different from other forms of HF for demographic, clinical, and prognostic features, its current pharmacological treatment does not significantly diverge. Methods: In this study we performed a Pubmed library search for placebo-controlled clinical investigations and a post-hoc analysis recruiting iDCM from 1985 to 2016. We searched for second-line pharmacologic treatments to reconsider drugs for iDCM management and pinpoint pathological mechanisms. Results: We found 33 clinical studies recruiting a total of 3392 patients of various durations and sizes, as well as studies that tested different drug classes (statins, pentoxifylline, inotropes). A metanalysis was unfeasible, although a statistical significance for changes upon treatment for molecular results, morphofunctional parameters, and clinical endpoints was reported. Statins appeared to be beneficial in light of their pleiotropic effects; inotropes might be tolerated more for longer times in iDCM compared to ischemic patients. General anti-inflammatory therapies do not significantly improve outcomes. Metabolic and growth modulation remain appealing fields to be investigated. Conclusions: The evaluation of drug effectiveness based on direct clinical benefit is an inductive method providing evidence-based insights. This backward approach sheds light on putative and underestimated pathologic mechanisms and thus therapeutic targets for iDCM management.

Effects of Surgical Ventricular Restoration on Left Ventricular Shape, Size, and Function for Left Ventricular Anterior Aneurysm

Background:

Surgical ventricular restoration (SVR) has been performed to treat left ventricular (LV) aneurysm. However, there is limited analysis of changes in LV shape. This study aimed to evaluate the changes in LV shape induced by SVR and the effects of SVR on LV size and function for LV aneurysm.

Methods:

Between April 2006 and March 2015, 18 patients with dyskinetic (dyskinetic group) and 12 patients with akinetic (akinetic group) postinfarction LV anterior aneurysm receiving SVR with the Dor procedure at Chinese People's Liberation Army General Hospital were enrolled in this study. A retrospective analysis was carried out using data from the echocardiography database. LV shape was analyzed by calculating the apical conicity index (ACI). LV end-diastolic volume index, end-systolic volume index, and ejection fraction (EF) were measured. One-way analysis of variance was used to compare means at different time points within each group.

Results:

Within one week after SVR, LV shape became more conical in the two groups (ACI decreased from 0.84 ± 0.13 to 0.69 ± 0.11 [t = 5.155, P = 0.000] in dyskinetic group and from 0.73 ± 0.07 to 0.60 ± 0.11 [t = 2.701, P = 0.026] in akinetic group; LV volumes were decreased significantly and became closer to normal values and EF was improved significantly in the two groups). On follow-up at least one year, LV shape remained unchanged in dyskinetic group (ACI increased from 0.69 ± 0.11 to 0.74 ± 0.12, t = −1.109, P = 0.294), but became more spherical in akinetic group (ACI significantly increased from 0.60 ± 0.11 to 0.75 ± 0.11, t = −1.880, P = 0.047); LV volumes remained unchanged in dyskinetic group, but increased significantly in akinetic group and EF remained unchanged in the two groups.

Conclusions:

SVR could reshape LV to a more conical shape and a more normal size and improve LV function significantly early after the procedure in patients with dyskinetic or akinetic postinfarction LV anterior aneurysm. However, LV tends to be more spherical and enlarged in the akinetic group on at least 1-year follow-up.

Depleted Leukocyte Mitochondrial DNA Copy Number Correlates With Unfavorable Left Ventricular Volumetric and Spherical Shape Remodeling in Acute Myocardial Infarction After Primary Angioplasty

BACKGROUND

Left ventricular (LV) shape influences LV systolic function. It is possible to assess LV shape using 3-D echocardiography sphericity index (SI). Maintaining mitochondrial DNA copy number (MCN) is important for preserving mitochondrial function and LV systolic function after acute myocardial infarction (AMI). Information is limited, however, regarding the relationship between leukocyte MCN and the subsequent change in LV shape after AMI.Methods and Results:Fifty-five AMI patients undergoing primary angioplasty were recruited. Plasma MCN was measured before primary angioplasty using quantitative polymerase chain reaction. 3-D echocardiography measurement of SI was performed at baseline, and at 1-, 3-, and 6-month follow-up. AMI subjects with MCN lower than the median had a higher 6-month SI and LV volume compared with those with higher MCN. Baseline echocardiographic parameters were similar between the 2 groups. MCN was negatively correlated with 3- and 6-month SI, and 3- and 6-month LV volume. On multiple linear regression analysis, baseline plasma MCN could predict LV SI and LV volume at 6 months after primary angioplasty for AMI, even after adjusting for traditional prognostic factors.

CONCLUSIONS

In AMI patients, higher plasma leukocyte MCN at baseline was associated with favorable LV shape and remodeling at 6-month follow-up. Plasma leukocyte MCN may provide a novel prognostic biomarker for LV remodeling after AMI.

New Parameter Derived from Three-Dimensional Speckle-Tracking Echocardiography for the Estimation of Left Ventricular Filling Pressure in Nondilated Hearts

BACKGROUND

E/e' is clinically useful for the noninvasive assessment of left ventricular (LV) filling pressure. However, its use in some conditions is controversial, and angle dependence of the Doppler measurement and preload dependence of mitral e' in nondilated hearts represent major problems. The ratio of early filling rate derived from the time derivative of LV volume to early diastolic strain rate (FRe/SRe), similar to E/e', by three-dimensional (3D) speckle-tracking echocardiography has the potential to address such limitations. This study investigated whether FRe/SRe could estimate acute changes in LV filling pressure using the models of volume overload and myocardial ischemia in the nondilated heart.

METHODS

In 25 dogs, hemodynamic conditions were varied by acute volume overload and coronary occlusion. FRe and SRe were obtained from the same beat and automatically analyzed by the 3D speckle-tracking method, and global SRe was measured from longitudinal (L-SRe), circumferential (C-SRe), and area strain rate (A-SRe). E/e' was measured by two-dimensional echocardiography. LV pressure was derived from a micromanometer catheter and recorded simultaneously with the acquisition of the 3D images.

RESULTS

Mitral e' and L-SRe varied by changes in preload, whereas C-SRe and A-SRe did not. C-SRe and A-SRe were more strongly correlated with the time constant of LV relaxation than mitral e' and L-SRe. FRe/C-SRe and FRe/A-SRe had relatively high correlations with LV preatrial contraction (pre-A) pressure and end-diastolic pressure, but E/e' and FRe/L-SRe did not. Receiver operating characteristics curve analysis showed that FRe/C-SRe and FRe/A-SRe had larger areas under the curve for the estimation of increased LV filling pressure.

CONCLUSIONS

The novel parameter FRe/SRe has potential as a surrogate marker of LV filling pressure. Especially in nondilated hearts, FRe/C-SRe and FRe/A-SRe may be useful to more accurately predict LV filling pressure than E/e', although their applicability in dilated hearts requires further investigation.

Posterior ventricular restoration treatment for heart failure: a review, past, present and future aspects

Congestive heart failure (CHF) is one of the major causes of death and occurs in more than 15,000,000 patients worldwide. The incidence is expected to increase in parallel with the aging population. Most current therapies for CHF are medications, and biventricular pacing implantation as appropriated by cardiologists, or surgical interventions. The heart transplantation for indicated patients is still gold standard surgery although the 10-year survival rate is approximately 60% based on the worldwide data. However, the cardiac transplantation remains epidemiologically insignificant because of donor pool limitations. New strategies for treating CHF are needed. In addition to conventional cardiac surgery, surgical ventricular restoration was reported as a promising surgical therapy in 1990s. After the first report of partial left ventriculectomy in which posterior wall was widely resected for dilated heart, many controversial clinical and animal research studies have been reported. In this review, the principles of posterior cardiac restoration therapy will be discussed. An overview of posterior cardiac restoration, structure, and torsion are presented. By understanding the structure of cardiac muscle, shape, and torsion of left ventricle for surgical restoration, the procedure can be performed based on appropriate indication and this knowledge can be used to optimize and improve its efficacy. The use of mechanical support devices has recently become commonplace in many centers, and the use of implantable ventricular assist devices as destination therapy will increase. Surgeons will be able to select several options of the treatment for CHF by understanding the advantages and disadvantages of those surgical treatments.

Current Treatment Strategies for Heart Failure: Role of Device Therapy and LV Reconstruction

OPINION STATEMENT

Medical care of heart failure (HF) begins with the determination of the cause of the heart failure and diagnosing potential reversible causes (i.e., coronary heart disease, hyperthyroidism, etc.). Medical therapy includes pharmacological and nonpharmacological strategies that limit and/or reverse the signs and symptoms of HF. Initial behavior modification includes dietary sodium and fluid restriction to avoid weight gain; and encouraging physical activity when appropriate. Optimization of medical therapy is the first line of treatment that includes the use of diuretics, vasodilators (i.e., ACE inhibitors or ARBs), beta blockers, and potentially inotropic agents and anticoagulation depending on the patient's severity of heart failure and LV dysfunction. As heart failure advances despite optimized medical management, cardiac resynchronization therapy (CRT), and implantable cardioverter defibrillators (ICDs) are appropriate device therapies. The development of progressive end-stage HF, despite maximal medical therapy, necessitates the consideration of mechanical circulatory devices such as ventricular assist devices (VADs) either as a bridge to heart transplantation or as destination therapy. Despite the advances in the treatment of heart failure, there is still a large morbidity and mortality associated with HF, thus the need to develop newer strategies for the treatment of HF.

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.

Cardiac Remodeling: Concepts, Clinical Impact, Pathophysiological Mechanisms and Pharmacologic Treatment

Cardiac remodeling is defined as a group of molecular, cellular and interstitial changes that manifest clinically as changes in size, mass, geometry and function of the heart after injury. The process results in poor prognosis because of its association with ventricular dysfunction and malignant arrhythmias. Here, we discuss the concepts and clinical implications of cardiac remodeling, and the pathophysiological role of different factors, including cell death, energy metabolism, oxidative stress, inflammation, collagen, contractile proteins, calcium transport, geometry and neurohormonal activation. Finally, the article describes the pharmacological treatment of cardiac remodeling, which can be divided into three different stages of strategies: consolidated, promising and potential strategies.

Combination of IGF‑1 gene manipulation and 5‑AZA treatment promotes differentiation of mesenchymal stem cells into cardiomyocyte‑like cells

Mesenchymal stem cell (MSC) transplantation has been proposed as a promising therapeutic strategy for ischemic myocardium repair following myocardial infarction. Differentiation of MSCs into cardiomyocyte-like cells prior to cell transplantation is advantageous in improving their potential clinical benefits for cardiac repair. In the present study, we isolated and cultured porcine MSCs and evaluated the synergistic effect of 5-azacytidine (5-AZA) treatment and insulin-like growth factor-1 (IGF-1) gene manipulation on MSC differentiation into cardiomyocyte-like cells. Our results demonstrated that 5-AZA treatment alone induced a limited cardiomyocyte-like differentiation effect in vitro. Overexpression of the IGF-1 gene in MSCs improved the induction effect of 5-AZA, while knockdown of the IGF-1 gene attenuated the differentiation. These results suggest that IGF-1 is a significant stimulus affecting the cardiomyocyte-like differentiation of porcine MSCs. In addition, the combination of IGF-1 gene manipulation and 5-AZA treatment provides a new strategy to obtain more committed differentiated cardiomyocyte-like cells from porcine MSCs prior to cell transplantation.

Ventricular structure-function relations in health and disease: part II. Clinical considerations

Normal cardiac function of the left and right ventricles, together with the septum, is related to form/function interactions within the helical ventricular myocardial band. This knowledge is a prerequisite to understanding form/function interactions in diseases and for planning new treatments. Topics discussed include congestive heart failure in dilated hearts of ischaemic, valvar or nonischaemic origin as well as diastolic dysfunction. Similar thinking underlies novel treatments for dyssynchrony in pacing, together with focusing upon varying global left or right ventricular anatomy to correct mitral and tricuspid insufficiency caused by tethering of the leaflets. The septum is the lion of the right ventricle and insight is provided into offsetting septal damage during cardiac surgery, rebuilding its anatomical structure in post-tetralogy pulmonary insufficiency, as well as rectifying its dysfunction by decompression in patients with a left ventricular assist device.

Label-free evaluation of myocardial infarction and its repair by spontaneous Raman spectroscopy

Raman spectroscopy, which provides information about molecular species and structures of biomolecules via intrinsic molecular vibrations, can analyze physiological and pathological states of tissues on the basis of molecular constituents without staining. In this study, we analyzed Raman spectra of myocardial infarction and its repair in rats using the hypothesis that the myocardium in the course of myocardial infarction and its repair could be recognized by spontaneous Raman spectroscopy on the basis of chemical changes in myocardial tissues. Raman spectra were acquired from unfixed frozen cross sections of normal and infarcted heart tissues upon excitation at 532 nm. Raman spectra of the infarcted tissues were successfully obtained at characteristic time points: days 2, 5, and 21 after coronary ligation, at which the main components of the infarcted region were coagulation necrosis, granulation tissue, and fibrotic tissue, respectively. The latent variable weights calculated by a multivariate classification method, partial least-squares-discriminant analysis (PLS-DA), revealed fundamental information about the spectral differences among the types of tissues on the basis of molecular constituents. A prediction model for the evaluation of these tissue types was established via PLS-DA. Cross-validated sensitivities of 99.3, 95.3, 96.4, and 91.3% and specificities of 99.4, 99.5, 96.5, and 98.3% were attained for the discrimination of normal, necrotic, granulation, and fibrotic tissue, respectively. A two-dimensional image of a marginal area of infarction was successfully visualized via PLS-DA. Our results demonstrated that spontaneous Raman spectroscopy combined with PLS-DA is a novel label-free method of evaluating myocardial infarction and its repair.

Applications of computational modeling in cardiac surgery

Although computational modeling is common in many areas of science and engineering, only recently have advances in experimental techniques and medical imaging allowed this tool to be applied in cardiac surgery. Despite its infancy in cardiac surgery, computational modeling has been useful in calculating the effects of clinical devices and surgical procedures. In this review, we present several examples that demonstrate the capabilities of computational cardiac modeling in cardiac surgery. Specifically, we demonstrate its ability to simulate surgery, predict myofiber stress and pump function, and quantify changes to regional myocardial material properties. In addition, issues that would need to be resolved in order for computational modeling to play a greater role in cardiac surgery are discussed.

The therapeutic effect of 2-cyclohexylthio-AMP in heart failure

AIM

: The aim of this study was to investigate the therapeutic effect of 2-cyclohexylthio-adenosine 5'-monophosphate (AMP) in mice with heart failure (HF).

METHODS

: 2-Cyclohexylthio-AMP was dissolved in phosphate-buffered saline and infused in mice with ischemic HF after permanent left coronary [left anterior descending (LAD)] ligation and in calsequestrin (CSQ) mice with HF. Myocardial function ex vivo was determined in the working heart model. Cardiac function in vivo was assessed by echocardiography.

RESULTS

: Injection of 2-cyclohexylthio-AMP induced a dose-dependent increase in +dP/dt, -dP/dt, and left ventricular developed pressure in normal wild-type mice and in CSQ mice with HF using the ex vivo working heart model. Spontaneous heart rate did not change after the injection of 2-cyclohexylthio-AMP. Compared with normal saline-treaded mice, chronic infusion of 2-cyclohexylthio-AMP in mice with ischemic HF after left coronary artery (LAD) ligation and in CSQ mice resulted in improved +dP/dt, -dP/dt, left ventricular developed pressure, and fractional shortening, restored the β-adrenergic response and decreased heart weight/body weight ratios.

CONCLUSIONS

: 2-Cyclohexylthio-AMP improved the cardiac contractile performance and rescued mice from HF. This salutary action may result from the reduction of myocardial hypertrophy and the restoration of the β-adrenergic response in both LAD ligation and CSQ mouse models of HF. The fact that this agent can increase contractile performance without heart rate increase should be desirable in HF therapy.

Analysis of patient-specific surgical ventricular restoration: importance of an ellipsoidal left ventricular geometry for diastolic and systolic function

Surgical ventricular restoration (SVR) is a procedure designed to treat heart failure by surgically excluding infarcted tissues from the dilated failing left ventricle. To elucidate and predict the effects of geometrical changes from SVR on cardiac function, we created patient-specific mathematical (finite-element) left ventricular models before and after surgery using untagged magnetic resonance images. Our results predict that the postsurgical improvement in systolic function was compromised by a decrease in diastolic distensibility in patients. These two conflicting effects typically manifested as a more depressed Starling relationship (stroke volume vs. end-diastolic pressure) after surgery. By simulating a restoration of the left ventricle back to its measured baseline sphericity, we show that both diastolic and systolic function improved. This result confirms that the increase in left ventricular sphericity commonly observed after SVR (endoventricular circular patch plasty) has a negative impact and contributes partly to the depressed Starling relationship. On the other hand, peak myofiber stress was reduced substantially (by 50%) after SVR, and the resultant left ventricular myofiber stress distribution became more uniform. This significant reduction in myofiber stress after SVR may help reduce adverse remodeling of the left ventricle. These results are consistent with the speculation proposed in the Surgical Treatment for Ischemic Heart Failure trial (20) for the neutral outcome, that "the lack of benefit seen with surgical ventricular reconstruction is that benefits anticipated from surgical reduction of left ventricular volume (reduced wall stress and improvement in systolic function) are counter-balanced by a reduction in diastolic distensibility."