Endoventricular Patch Reconstruction of Ischemic Failing Ventricle. A Single Center with 20 years Experience. Advantages of Magnetic Resonance Imaging Assessment

Postmyocardial Infarction Ventricular Aneurysm: JACC Focus Seminar 5/5

Ventricular aneurysm represents a rare complication of transmural acute myocardial infarction, although other cardiac, congenital, or metabolic diseases may also predispose to such condition. Ventricular expansion includes all the cardiac layers, usually with a large segment involved. Adverse events include recurrent angina, reduced ventricular stroke volume with congestive heart failure, mitral regurgitation, thromboembolism, and ventricular arrhythmias. Multimodality imaging is paramount to provide comprehensive assessment, allowing for appropriate therapeutic decision-making. When indicated, surgical intervention remains the gold standard, although additional therapy (heart failure, anticoagulation, and advanced antiarrhythmic treatment) might be required. However, the STICH (Surgical Treatment for Ischemic Heart Failure) trial did not show any advantage from adding surgical ventricular reconstruction to coronary artery bypass surgery in terms of survival, rehospitalization or symptoms, compared with revascularization alone. Finally, implantable cardiac defibrillator may reduce the risk of fatal arrhythmias.

Concomitant Mitral Valve Repair vs Replacement During Surgical Ventricular Restoration for Ischemic Cardiomyopathy

There is no consensus regarding mitral valve management during surgical ventricular restoration (SVR) for ischemic cardiomyopathy. We compared the impact of SVR with mitral valve repair (MVr) vs replacement (MVR) on postoperative outcomes and long-term survival in ischemic cardiomyopathy and mitral regurgitation patients. This study included 112 patients who underwent SVR from 2009 to 2018 with MVr (n = 75) or MVR (n = 37). Patients who had MVR had higher Euro SCORE II, dyspnea class, a lower ejection fraction, higher pulmonary artery systolic pressure, higher grade of preoperative mitral and tricuspid regurgitation, and higher end-diastolic and end-systolic diameters. Intra-aortic balloon pump was more commonly used in patients with MVR. Hospital mortality occurred in 7 (9.33%) patients in the MVr group vs 3 (8.11%) in the MVR group (P > .99). Freedom from rehospitalization at 1, 5, and 7 years was 87%, 76%, and 70% in the MVr group and 83%, 61%, and 52% in the MVR group (P = .191). Survival at 1, 5, and 7 years was 88%, 78%, and 74% in the MVr group and 88%, 56%, and 56% in the MVR group (P = .027). Adjusted survival did not differ between groups.MVr or MVR are valid options in patients undergoing SVR, with good long-term outcomes.

Transmural myocardial repair with engineered heart muscle in a rat model of heterotopic heart transplantation - A proof-of-concept study

Engineered heart muscle (EHM) can be implanted epicardially to remuscularize the failing heart. In case of a severely scarred ventricle, excision of scar followed by transmural heart wall replacement may be a more desirable application. Accordingly, we tested the hypothesis that allograft (rat) and xenograft (human) EHM can also be administered as transmural heart wall replacement in a heterotopic, volume-loaded heart transplantation model. We first established a novel rat model model to test surgical transmural left heart wall repair. Subsequently and in continuation of our previous allograft studies, we tested outcome after implantation of contractile engineered heart muscle (EHM) and non-contractile engineered connective tissue (ECT) as well as engineered mesenchymal tissue (EMT) allografts as transmural heart wall replacement. Finally, proof-of-concept for the application of human EHM was obtained in an athymic nude rat model. Only in case of EHM implantation, remuscularization of the surgically created transmural defect was observed with palpable graft vascularization. Taken together, feasibility of transmural heart repair using bioengineered myocardial grafts could be demonstrated in a novel rat model of heterotopic heart transplantation.

Surgical Restoration of Antero-Apical Left Ventricular Aneurysms: Cardiac Computed Tomography for Therapy Planning

Background

Surgical ventricular restoration (SVR) leads to functional improvement by volume reduction and restoration of left ventricular (LV) geometry. Our purpose was to refine the planning for SVR using cardiac computed tomography (CCT).

Methods

The possibility to anticipate the postoperative residual LV volume was assessed using CCT in 205 patients undergoing SVR combined with coronary artery bypass grafting (77%), mitral valve repair/replacement (19%) and LV thrombectomy (19%). The potential of CCT to guide the procedure was evaluated. Additionally, the predictive value of CCT characteristics on survival was addressed.

Results

30-day, 1- and 5-year survival was 92.6, 82.7, and 72.1%, respectively, with a marked reduction of NYHA class III-IV quota after surgery (95.1% vs. 20.5% in the follow-up). Both pre- and postoperative LV end-systolic volume index (LVESVI) were predictive of all defined endpoints according to the following tertiles: preoperative: <74 ml/m², 74–114 ml/m² and >114 ml/m²; postoperative: <58 ml/m², 58–82 ml/m² and >82 ml/m². On average, a 50 ml/m² increase of preoperative LVESVI was associated with a 35% higher hazard of death (p = 0.043). Aneurysms limited to seven antero-apical segments (1–7) were associated with a lower death risk (n = 60, HR 0.52, CI 0.28–0.96, p = 0.038). LVESVI predicted by CCT was found to correlate significantly with effectively achieved LVESVI (r = 0.87 and r = 0.88, respectively, p < 0.0001).

Conclusions

CCT-guided SVR can be performed with good mid-term survival and significant improvement in HF severity. CCT-based assessment of achievable postoperative LV volume helps estimate the probability of therapeutic success in individual patients.

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.

Influence of preoperative right ventricular function on left ventricular remodeling and survival after subvalvular repair for functional mitral regurgitation

OBJECTIVES

The objective of this study was to analyze our surgical experiences with mitral valve plasty (MVP) combined with subvalvular procedures (SVPs) for functional mitral regurgitation (FMR) and to determine which preoperative factors affected clinical outcomes.

METHODS

This study retrospectively analyzed 33 patients who underwent MVP combined with SVPs for FMR with a left ventricular ejection fraction lower than 40% and advanced remodeled left ventricles. The mean follow-up period was 49 ± 33 months.

RESULTS

The preoperative mean right ventricular fractional area change (RVFAC) used to quantify right ventricular (RV) systolic function was 26 ± 11%. Sixteen patients (48%) had an RVFAC < 26%. One patient died during hospital stay, and nine more patients died of cardiac causes during follow-up. The 3- and 5-year rates of freedom from cardiac-related mortality were 78% and 68%, respectively. RVFAC was the significant predictor of cardiac-related mortality in a univariate analysis (risk ratio [RR] = 0.92, 95% confidence interval [CI] 0.85-0.99, p = 0.03) and demonstrated a non-significant tendency to predict cardiac-related mortality in the Cox multivariate analysis (RR = 0.94, 95% CI 0.86-1.003, p = 0.08). Continued reverse left ventricular remodeling was associated with an RVFAC ≥ 26%. At 3 years, there was also a significant difference in survival rates of cardiac-related mortality between patients with an RVFAC ≥ 26% and < 26% (94% vs. 61%; p = 0.03).

CONCLUSIONS

Preoperative RV function affected left ventricular remodeling and cardiac-related mortality after MV surgery. MVP combined with SVPs for FMR provided promising results for patients without severe RV dysfunction.

Clinical Outcomes of a Customized Mitral Valve Plasty for Functional Mitral Regurgitation with a Low Ejection Fraction and Implications for Preoperative Right Ventricular Function

Purpose: To evaluate clinical outcomes of customized mitral valve plasty (MVP) for the treatment of functional mitral regurgitation (FMR) with a low ejection fraction (EF) and to determine which preoperative factors affected the clinical outcome.

Methods and Results: MVP was adjusted according to the degree of left ventricle (LV) remodeling. We performed mitral annuloplasty (MAP) alone in 14 patients and added subvalvular procedures (SVPs) in 22 patients at a high risk of recurrent MR. During follow-up, reverse LV remodeling was obtained and the 3-year and 5-year non-recurrence rates of MR grade ≥2 were 94% and 89%, respectively. Two patients died during their hospital stay, and four more patients died of cardiac causes during follow-up. The 3-year and 5-year rates of freedom from cardiac-related mortality were 86% and 81%, respectively; no significant difference was observed between the two treatment groups. Right ventricular fractional area change (RVFAC) was a significant predictor of cardiac mortality. Patients with an RVFAC of <26% had significantly poorer cardiac-related mortality (71% at 3 years) than those with an RVFAC of ≥26% (95% at 3 years).

Conclusion: Customized MVP provided durable mitral competence and reverse LV remodeling. Preoperative RV function was associated with cardiac-related mortality.

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.

A combined cellular and surgical ventricular reconstruction therapeutic approach produces attenuation of remodeling in infarcted rats

BACKGROUND

Left ventricular reconstruction (LVR) has been shown to provide transient benefits to the LV structure and function of infarcted hearts; however, long-term results have been disappointing as LVR-induced benefits are typically not sustained. We hypothesized that administration of cardiosphere-derived cells (CDCs), which promote myocardial repair and regeneration, may result in long-term preservation of the beneficial effects of LVR in ischemic cardiomyopathy.

METHODS

Wistar Kyoto rats underwent myocardial infarction (MI) and two weeks later were randomized into 3 groups: in Group 1 (n=9), LVR was performed by plication of the infarcted apex and CDCs were injected in the infarct border zone (IBZ); group 2 animals (n=9) underwent LVR and received vehicle solution in the IBZ; and Group 3 animals (n=10) were injected with vehicle solution in the IBZ without undergoing LVR. Echocardiograms were performed at baseline, 4 days post-apex plication, and at 3 months post-MI.

RESULTS

At baseline, all animal groups had a comparable LVEF, LV end-diastolic volume (EDV) and LV end-systolic volume (ESV). Four days post-LV apex plication, Group 1 and Group 2 animals exhibited comparable significant improvement in EF and comparable significant reduction in LVEDV and LVESV. Three months post-MI, Group 1 animals had a decreased LVEDV, decreased LVESV, less impaired CS, increased peak systolic torsion and increased EF compared to animals in Groups 2 and 3.

CONCLUSION

In infarcted rat hearts, intramyocardial delivery of CDCs in conjunction with LVR resulted in significant and sustained amelioration of LV remodeling and improvement in LV function compared to LVR alone.

Multislice computed tomography-guided surgical repair of acquired posterior left ventricular aneurysms: demonstration of mitral valve and left ventricular reverse remodelling

OBJECTIVES

Involvement of the mitral valve (MV) apparatus represents a challenge in surgical ventricular repair (SVR) of posterior left ventricular (LV) aneurysms. This study sought to investigate whether multislice computed tomography (MSCT) assessment can be used to optimize the surgical procedure for posterior LV aneurysms.

METHODS

Thirty patients (m : w = 24 : 6, age 38-78, median 66 years; mean New York Heart Association class 2.98) with posterior LV aneurysm were operated upon. MSCT was performed in 24 patients before and after surgery. End-diastolic and end-systolic volumes of LV and aneurysm were indexed to body surface area (LVEDVI/LVESVI, AEDVI/AESVI). The MV apparatus was characterized by coaptation distance (CD), tenting area (TA), MV closure angle (MVCA), MV annulus area (MVAA) and interpapillary muscle distance (IMD).

RESULTS

Thirty-day mortality was 10% and 5-year survival rate was 83%. After surgery, LVEDVI decreased from 151.2 ± 84.1 to 85.7 ± 28.3 ml/m(2) (P = 0.001) and LVESVI from 110.6 ± 88.8 to 50.2 ± 22.9 ml/m(2) (P = 0.001). LV ejection fraction increased from 31.5 ± 15.1 to 43.4 ± 9.9% (P = 0.001). Preoperative MSCT showed significantly higher values of MVAA, CD and TA in patients who needed MV repair or replacement. Postoperative reduction of mitral regurgitation in patients without MV surgery corresponded with significant reduction in intercommissural diameter, anteroposterior diameter, MVAA, TA, CD, MVCA and IMD.

CONCLUSIONS

MSCT represents an excellent diagnostic tool for the assessment of MV and LV geometry. MSCT-guided SVR of submitral LV aneurysms leads to excellent mid-term results. On the basis of the MSCT assessment, we propose an algorithm for surgical planning in posterior LV aneurysms.

Biomechanics of Cardiac Function

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here, we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments.

[Preoperative and follow-up cardiac magnetic resonance imaging of candidates for surgical ventricular restoration]

PURPOSE

To assess pre and post-operative cardiac MRI (CMR) findings in patients with left endoventriculoplasty repair for ventricular aneurysm due to ischemic heart disease.

MATERIAL AND METHODS

Data were retrospectively gathered on 21 patients with diagnosis of ventricular aneurysm secondary to ischemic heart disease undergoing left endoventriculoplasty repair between January 2007 and March 2013. Pre and post-operative CMR was performed in 12 patients. The following data were evaluated in pre-operative and post-operative CMR studies: quantitative analysis of left ventricular ejection fraction (LVEF), left ventricular end-diastolic (LVEDV) and end-systolic (LVESV) volume index, presence of valvular disease and intracardiac thrombi. The time between surgery and post-operative CRM studies was 3-24 months.

RESULTS

Significant differences were found in the pre and post-operative LVEF, LVEDV and LVESV data. EF showed a median increase of 10% (IQR 2-15) (p=0.003). The LVEDV showed a median decrease of 38 ml/m(2) (IQR 18-52) (p=0.006) and the LVESV showed a median decrease of 45 ml/m(2) (IQR:12-60) (p=0.008). Post-operative ventricular volume reduction was significantly higher in those patients with preoperative LVESV >110 ml/m(2) (59 ml/m(2) and 12 ml/m(2), p=0.006).

CONCLUSION

In patients with ischemic heart disease that are candidates for left endoventriculoplasty, CMR is a reliable non-invasive and reproducible technique for the evaluation of the scar before the surgery and the ventricular volumes and its evolution after endoventricular surgical repair.

Surgical ventricular restoration for the treatment of heart failure

Heart failure (HF) is an emerging epidemic affecting 15 million people in the USA and Europe. HF-related mortality was unchanged between 1995 and 2009, despite a decrease in the incidence of cardiovascular disease. Conventional explanations include an aging population and improved treatment of acute myocardial infarction and HF. An adverse relationship between structure and function is the central theme in patients with systolic dysfunction. The normal elliptical ventricular shape becomes spherical in ischemic, valvular, and nonischemic dilated cardiomyopathy. Therapeutic decisions should be made on the basis of ventricular volume rather than ejection fraction. When left ventricular end-systolic volume index exceeds 60 ml/m², medical therapy, CABG surgery, and mitral repair have limited benefit. This form-function relationship can be corrected by surgical ventricular restoration (SVR), which returns the ventricle to a normal volume and shape. Consistent early and late benefits in the treatment of ischemic dilated cardiomyopathy with SVR have been reported in >5,000 patients from various international centers. The prospective, randomized STICH trial did not confirm these findings and the reasons for this discrepancy are examined in detail. Future surgical options for SVR in nonischemic and valvular dilated cardiomyopathy, and its integration with left ventricular assist devices and cell therapy, are described.

Surgical ventricular reconstruction with endocardectomy along radiofrequency ablation-induced markings

OBJECTIVE

The objective of this study was to evaluate the efficacy of a novel approach for endocardectomy during coronary artery bypass graft with surgical ventricular restoration in patients with postinfarction left ventricular aneurysm.

METHODS

One hundred sixty-eight patients underwent coronary artery bypass graft with surgical ventricular restoration from 2005 to 2011. Endocardectomy was performed as an integral part of surgical ventricular restoration for the prevention of ventricular tachycardia. The experimental group (surgical ventricular restoration-endocardectomy group; n = 74) underwent preoperative electrophysiologic study with electroanatomic left ventricular mapping. Radiofrequency ablation-induced markings were placed and were used later as guides for performing endocardectomy during coronary artery bypass graft with surgical ventricular restoration. The control group (surgical ventricular restoration group; n = 94) underwent surgical ventricular restoration without endocardectomy.

RESULTS

The 1-year mortality rates in the surgical ventricular restoration-endocardectomy and surgical ventricular restoration (control) groups were 5% and 13%, respectively. During the postoperative period, 3% of patients in the surgical ventricular restoration-endocardectomy group and 38% of patients in the surgical ventricular restoration group experienced ventricular tachycardia events (P < .05). Automatic implantable cardioverter-defibrillators were implanted in 11 patients in the surgical ventricular restoration group and in 1 patient of the surgical ventricular restoration-endocardectomy group for secondary prevention of sudden cardiac death.

CONCLUSIONS

When performed as an integral part of surgical ventricular restoration, endocardectomy was crucial in preventing postoperative ventricular tachycardia. Use of radiofrequency ablation-induced markings allowed clear visualization of the reentry zones for efficient endocardectomy during coronary artery bypass graft with surgical ventricular restoration, resulting in better patient outcomes.

Three-dimensional echocardiography for the preoperative assessment of patients with left ventricular aneurysm

BACKGROUND

Surgical ventricular reconstruction has been proposed as a treatment option in heart failure patients with left ventricular (LV) aneurysm. The feasibility of this procedure has some limitations, and extensive preoperative evaluation is necessary to give the correct indication. For this purpose, magnetic resonance imaging (MRI) is currently considered the gold standard, providing accurate quantification of LV shape, size, and global and regional function together with the assessment of myocardial scar and mitral regurgitation severity. The aim of this study was to evaluate the accuracy of real-time three-dimensional echocardiography (RT3DE) as a potential alternative to MRI for this evaluation.

METHODS

A total of 52 patients with ischemic cardiomyopathy and LV aneurysm underwent a comprehensive analysis with two-dimensional echocardiography, RT3DE, and MRI.

RESULTS

Excellent correlation (r=0.97, p<0.001) and agreement were found between RT3DE and MRI for quantification of LV volumes, ejection fraction, and sphericity index; in a segment-to-segment comparison, RT3DE was shown to be accurate also for the analysis of wall motion abnormalities (k=0.62) and LV regional thickness (k=0.56) as a marker of myocardial scar. In contrast, two-dimensional echocardiography significantly underestimated these variables. Furthermore, mitral regurgitant volume assessed by RT3DE showed excellent correlation (r=0.93) with regurgitant volume measured by MRI, without significant bias (=-0.7 mL/beat).

CONCLUSIONS

In the management of heart failure patients with LV aneurysm, RT3DE provides an accurate and comprehensive assessment, including quantification of LV size, shape, global systolic function, regional wall motion, and myocardial scar together with precise evaluation of the severity of mitral regurgitation.

A novel miniaturized multimodal bioreactor for continuous in situ assessment of bioartificial cardiac tissue during stimulation and maturation

Stem cell-based cardiac tissue engineering is a promising approach for regenerative therapy of the injured heart. At present, the small number of stem cell-derived cardiomyocytes that can be obtained using current culture and enrichment techniques represents one of the key limitations for the development of functional bioartificial cardiac tissue (BCT). We have addressed this problem by construction of a novel bioreactor with functional features of larger systems that enables the generation and in situ monitoring of miniaturized BCTs. BCTs were generated from rat cardiomyocytes to demonstrate advantages and usefulness of the bioreactor. Tissues showed spontaneous, synchronized contractions with cell orientation along the axis of strain. Cyclic stretch induced cardiomyocyte hypertrophy, demonstrated by a shift of myosin heavy chain expression from the alpha to beta isoform, together with elevated levels of atrial natriuretic factor. Stretch led to a moderate increase in systolic force (1.42 ± 0.09 mN vs. 0.96 ± 0.09 mN in controls), with significantly higher forces observed after β-adrenergic stimulation with noradrenalin (2.54 ± 0.11 mN). Combined mechanical and β-adrenergic stimulation had no synergistic effect. This study demonstrates for the first time that mechanical stimulation and direct real-time contraction force measurement can be combined into a single multimodal bioreactor system, including electrical stimulation of excitable tissue, perfusion of the culture chamber, and the possibility of (fluorescence) microscopic assessment during continuous cultivation. Thus, this bioreactor represents a valuable tool for monitoring tissue development and, ultimately, the optimization of stem cell-based tissue replacement strategies in regenerative medicine.

Surgical Ventricular Restoration: An Operation to Reverse Remodeling - Clinical Application (Part II)

The first part of the article dealt with the basic science behind the evolution of ventricular restoration procedures and the rationale for the use of novel surgical techniques. The second part describes the preoperative workup of patients in advanced heart failure, the core information required to determine the surgical approach and the essential principles and techniques of ventricular restoration. It then examines the effects of ventricular restorative procedures on pump function and clinical outcomes, the results of the worldwide experience with ventricular restoration and concludes with more recent advances in this field.

Design of a 3D aligned myocardial tissue construct from biodegradable polyesters

The heart does not regenerate new functional tissue when myocardium dies following coronary artery occlusion, or if it is defective. Ventricular restoration involves excising the infarct and replacing it with a cardiac patch to restore the heart to a more healthy condition. The goal of this study was to design and develop a clinically applicable myocardial patch to replace myocardial infarcts and improve long-term heart function. A basic design composed of 3D microfibrous mats that house mesenchymal stem cells (MSCs) was developed from human umbilical cord matrix (Wharton's Jelly) cells aligned in parallel to each other mimicking the native myocardium. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(L-D,L-lactic acid) (P(L-D,L)LA) and poly(glycerol sebacate) (PGS) were blended and electrospun into aligned fiber mats with fiber diameter ranging between 1.10 and 1.25 microm. The micron-sized parallel fibers of the polymer blend were effective in cell alignment and cells have penetrated deep within the mat through the fiber interstices, occupying the whole structure; 8-9 cell layers were obtained. Biodegradable macroporous tubings were introduced to serve as nutrient delivery route. It was possible to create a thick myocardial patch with structure similar to the native tissue and with a capability to grow.

Resizable ventricular patch plasty in the porcine left ventricle: a pilot study

OBJECTIVE

: Endoventricular circular patch plasty is a method used to reconstruct the ventricular cavity in patients with (post) ischemic left ventricular aneurysm or global dilatation. However, late redilatation with mitral regurgitation has been reported, in which postoperative apex shape seems to play an important role. We studied the feasibility of ventricular volume downsizing with a variably shaped patch in porcine hearts.

METHODS

: In five in vitro and two acute animal experiments, a dyskinetic aneurysm was simulated with a pericardial insert. Reducing patch surface by changing patch shape diminished end-diastolic volume. In vitro, static end-diastolic volume was determined for each patch shape using volumetry and echocardiography. In the acute animal experiments, preliminary observations of patch behavior in live material were made, and pressure/time relationship, dPdTmax, was registered.

RESULTS

: In vitro, bringing the convex patch into a flat plane reduced LV volume from 66 ± 7 mL (aneurysm) to 49 ± 5 mL. Four of 5 patch shapes further reduced volume to a mean of 38 ± 7 mL (P = 0.03). The in vitro echocardiographic measurements correlated with volumetry findings (r = 0.81). In the acute animal experiments, dPdTmax varied with patch shape, independent of volume changes.

CONCLUSIONS

: In this pilot study, in vitro shape configuration of the resizable ventricular patch resulted in a calibrated end-diastolic volume reduction. The data of the two in vivo pilot experiments clearly indicate that change in patch configuration in the situation of more or less unchanged end-diastolic volume had impact on cardiac performance. Future studies must substantiate the results of this observation.

Delayed enhancement cardiovascular magnetic resonance as a novel technique to predict cardiac events in dilated cardiomyopathy patients

PURPOSE

Delayed enhancement cardiovascular magnetic resonance (DE-CMR) can detect cardiac scarring and has the potential to visualize the progression of myocardial remodeling. We determined whether DE-CMR can predict cardiac events in dilated cardiomyopathy patients.

MATERIALS AND METHODS

Transthoracic echocardiography, coronary arteriography, and DE-CMR studies were performed in 60 consecutive dilated cardiomyopathy (DCM) patients. Percent delayed enhancement (%DE) was determined as the ratio of the area showing delayed enhancement to the total myocardial area in three short-axis views. Patients were classified as advanced group (Group A) when %DE was 10% or higher, and as non-advanced group (Group NA) when %DE was less than 10%. The incidence of cardiac events and the clinical history were compared between Group A and Group NA.

RESULTS

There were 11 patients in Group A and 49 patients in Group NA. The incidence of cardiac events was significantly higher in Group A (36%; 4/11 patients) than in Group NA (2.0%; 1/49 patients) (log rank, p=0.0001).

CONCLUSION

DE-CMR is a useful tool to predict cardiac events in DCM patients.