Late hemodynamic results after left ventricular patch repair associated with coronary grafting in patients with postinfarction akinetic or dyskinetic aneurysm of the left ventricle

Effects of trehalose on recurrence of remodeling after ventricular reconstruction in rats with ischemic cardiomyopathy

Recurrence of left ventricular (LV) remodeling after surgical ventricular reconstruction (SVR) for ischemic cardiomyopathy has been reported to be partially attributed to autophagy. We aimed to examine the effects of trehalose, an autophagy inducer, on the recurrence of LV remodeling after SVR. After SVR in rats with ICM, trehalose was orally administered. The changes in LV end-diastolic dimension (LVEDD) and fractional shortening (FS) were evaluated. The activation of myocardial autophagy was also estimated by autophagy markers: microtubule-associated light chain 3 II (LC3-II) and p62; the former usually increases and the latter decreases if autophagy is activated. Significant LV reverse remodeling was observed early after SVR. On the other hand, the 28th postoperative day SVR + trehalose was associated with smaller LVEDD and better FS than SVR alone (LVEDD, P = 0.043; FS, P < 0.01). LC3-II increased comparably in both groups, while p62 was significantly lower in the SVR + trehalose group than in the SVR alone group (P < 0.01). In conclusion, trehalose attenuated the recurrence of LV remodeling and changed autophagy markers after SVR in rats with ICM. Trehalose may be a candidate for adjuvant therapy to retain the effects of SVR.

Basic fibroblast growth factor attenuates left-ventricular remodeling following surgical ventricular restoration in a rat ischemic cardiomyopathy model

OBJECTIVE

Although surgical ventricular restoration for ischemic cardiomyopathy is expected as an alternative or bridge to heart transplantation, post-operative remodeling of left ventricle (LV) needs to be addressed. This study aimed to examine the effect of basic fibroblast growth factor (bFGF), which induces angiogenesis and tissue regeneration in ischemic myocardium, to prevent remodeling after surgical ventricular restoration (SVR) using a rat ischemic cardiomyopathy model.

METHODS

Four weeks after coronary artery ligation, rats were divided into two groups: rats treated with SVR alone (SVR; n = 21), and rats treated with SVR and local sustained release of bFGF using gelatin hydrogel sheet (SVR + bFGF; n = 22). Cardiac function was assessed by serial echocardiography and cardiac catheterization. Cardiac tissue sections were histologically examined for vascular density and fibrosis.

RESULTS

Higher systolic function and lower LV end-diastolic pressure (LVEDP) were observed in rats treated with SVR + bFGF (SVR vs SVR + bFGF; Ees: 0.22 ± 0.11 vs 0.33 ± 0.22 mmHg/μL, p = 0.0328; LVEDP: 12.7 ± 7.0 vs 8.5 ± 4.3 mmHg, p = 0.0230). LV area tended to be lower in rats treated with SVR + bFGF compared to rats treated with SVR alone (left-ventricular end-diastolic area: 0.66 ± 0.07 vs 0.62 ± 0.07 cm², p = 0.071). Vascular density tended to be higher in rats treated with SVR + bFGF than those without bFGF (23.3 ± 8.1 vs 28.8 ± 9.5/mm², p = 0.0509).

CONCLUSIONS

BFGF induced angiogenesis and attenuated remodeling after SVR which secured the efficacy of SVR in a rat ischemic cardiomyopathy model.

Myocardial reconstruction in ischaemic cardiomyopathy

An increase in left ventricular volume after a myocardial infarction is a key component of the adverse remodelling process leading to chamber dysfunction, heart failure and an unfavourable outcome. Hence, the therapeutic strategies have been designed to reverse the remodelling process by medical therapy, devices or surgical strategies. Surgical ventricular reconstruction primarily combined with myocardial revascularization has been introduced as an optional intervention aimed to reduce the left ventricle through resection of the scar tissue and is recommended in selected patients with predominant heart failure symptoms, and with myocardial scarring and moderate left ventricular remodelling. This review outlines the rationale and the technique for reconstructing the left ventricle and the possible indications for using that technique, based on experiences from the centre with the largest international experience. The major contributions in the literature are briefly discussed.

Long-Term Survival and Echocardiographic Findings After Surgical Ventricular Restoration

BACKGROUND

This study investigates the long-term survival and durability of mitral procedures on patients undergoing surgical ventricular restoration.

METHODS

From 1992 to 2017, 109 patients underwent surgical ventricular restoration. Survival was determined from hospital records and the National Death Index. Preoperative demographics, clinical characteristics and features, operative technique, and follow-up echocardiography findings were analyzed using Cox regression and log-rank to determine variables influencing survival.

RESULTS

The mean age was 61.57 ± 12.81 years. There were 101 (93%) true and 8 (7%) pseudo-aneurysms. Concomitant surgeries included mitral valve (MV) repair (n = 40, 37%), MV replacement (n = 5, 5%), tricuspid valve repair (n = 4, 4%), aortic valve replacement (n = 3, 3%), coronary bypass grafting (n = 76, 70%; 1.6 ± 1.3 grafts), and ventricular septal defect closure (n = 5, 5%). Redo-sternotomies were performed in 12 patients (11%). Median duration of echocardiographic follow up was 2.9 years (interquartile range, 9.0) and was obtained in 59 patients (54%). Left ventricular ejection fraction improved from 28% ± 13% to 33% ± 16% (p = 0.011). Median duration of echocardiographic follow-up of MV repair was 3.6 years (interquartile range, 9.5). MV repair led to sustained improvements in mitral regurgitation (MR; p = 0.001) where only 2 (5%) experienced recurrence of moderate to severe MR. For patients who did not undergo an MV procedure there was no difference in preoperative and follow-up MR severity (p = 0.586). Median patient follow-up was 7.1 years (interquartile range, 8.5). Overall 5-, 10-, and 15-year survival rates were 71.9%, 48.1%, and 26.2%, respectively.

CONCLUSIONS

Surgical ventricular restoration was associated with sustained improvement in left ventricular ejection fraction with almost half surviving to 10 years postoperatively. For patients undergoing concomitant MV repair, the improvement in mitral competence is durable.

Left Ventricular Reconstruction for Postinfarction Left Ventricular Aneurysm: Review of Surgical Techniques

Different surgical techniques, each with its own advantages and disadvantages, have been used to reverse adverse left ventricular remodeling due to postinfarction left ventricular aneurysm. The most appropriate surgical technique depends on the location and size of the aneurysm and the scarred tissue, the patient's preoperative characteristics, and surgeon preference. This review covers the reconstructive surgical techniques for postinfarction left ventricular aneurysm.

New Insights in the Diagnosis and Treatment of Heart Failure

Cardiovascular disease is the leading cause of mortality in the US and in westernized countries with ischemic heart disease accounting for the majority of these deaths. Paradoxically, the improvements in the medical and surgical treatments of acute coronary syndrome are leading to an increasing number of “survivors” who are then developing heart failure. Despite considerable advances in its management, the gold standard for the treatment of end-stage heart failure patients remains heart transplantation. Nevertheless, this procedure can be offered only to a small percentage of patients who could benefit from a new heart due to the limited availability of donor organs. The aim of this review is to evaluate the safety and efficacy of innovative approaches in the diagnosis and treatment of patients refractory to standard medical therapy and excluded from cardiac transplantation lists.

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.

Left ventricular aneurysm repair with use of a bovine pericardial patch

Left ventricular aneurysm, which can impair systolic function, has a reported incidence of 10% to 35% in patients after myocardial infarction. In a 58-year-old woman who had a history of myocardial infarction, we excised a large left ventricular aneurysm and restored left ventricular geometry with use of a bovine pericardial patch. The aneurysm's characteristics and the patient's preoperative left ventricular ejection fraction of 0.25 had indicated surgical intervention. The patient had an uneventful postoperative course, and her left ventricular ejection fraction was 0.50 to 0.55 on the 4th postoperative day. This case illustrates the value of surgical treatment for patients who have a debilitating left ventricular aneurysm.

Epicardial catheter-based ventricular reconstruction: a novel therapy for ischaemic heart failure with anteroapical aneurysm

OBJECTIVES

Surgical ventricular reconstruction has been used to treat ischaemic cardiomyopathy with large akinetic or dyskinetic areas. However, application of this approach requires a sternotomy, cardiopulmonary bypass and a left ventriculotomy. This study assessed the feasibility and efficacy of minimally invasive, off-pump, epicardial catheter-based ventricular reconstruction (ECVR) in an anteroapical aneurysm ovine model.

METHODS

Left ventricular (LV) anteroapical myocardial infarction was induced percutaneously by coil embolization of the left anterior descending coronary artery. Eight weeks after infarction, via mini left thoracotomy and without cardiopulmonary bypass, ECVR was performed in six sheep. The scar was excluded by placing anchor pairs on the LV epicardial anterior wall and the right ventricular side of the interventricular septum under fluoroscopic guidance. LV performance was evaluated before, immediately after device implantation and after 6 weeks by echocardiography. Terminal histopathology was performed.

RESULTS

ECVR was completed expeditiously in all animals without complications. Parameters obtained 6 weeks after device implantation were compared with baseline (pre-device). End-systolic volume was decreased by 38% (25.6 ± 6.1 ml vs baseline 41.2 ± 7.2 ml, P = 0.02) with preservation of stroke volume. Ejection fraction was significantly increased by 13% (48.5 ± 7% vs baseline 35.8 ± 7%, P = 0.02). The circumferential strain in the anterior septum (-7.67 ± 5.12% vs baseline -0.96 ± 2.22%, P = 0.03) and anterior wall (-9.01 ± 3.51% vs baseline -4.15 ± 1.36%, P = 0.01) were significantly improved. The longitudinal strain in apex was reversed (-3.08 ± 1.53% vs baseline 3.09 ± 3.39%, P = 0.01). Histopathology showed full endocardial healing over the anchors with appreciable reduction of the chronic infarct in the LV.

CONCLUSIONS

ECVR without cardiopulmonary bypass is a less invasive alternative to current standard therapies, reverses LV remodelling and improves cardiac performance in an ovine model of anteroapical aneurysm.

Early results after surgical treatment of left ventricular aneurysm

Background

Left ventricular aneurysm (LVA) is a serious complication of myocardial infarction and reduces the chances of survival. Controversy still exists regarding the optimal surgical technique for LVA repair. We analyze the efficacy of two techniques, linear vs. endoventricular circular patch plasty, for repair of LVA and the efficacy of surgical ventricular restoration (SVR) on beating heart.

Methods

This study included 62 patients who underwent SVR from 1086 consecutive patients were subjected to coronary artery bypass grafting (CABG) between 2000 and 2009. All selected patients were divided either into group liner or patch according to the choice of the repair technique depended on factors such as localization, size and dimension of the scar. The patients also were divided either into group beating heart or cardioplegia. The pre-, intra- and postoperative relevant data of all selected patients were analyzed.

Results

The mortality was not significantly different between linear and patch repair groups, also the actuarial survival rates within 24 months (p= 0.529). Postoperative echocardiographic findings showed significant improvements in left ventricular function in both groups. The beating heart technique reduced postoperative peak release by 27% for Cardiac troponin I (cTnI) compared with the cardioplegia group (0.46 ± 0.06 ng/mL versus 0.63 ± 0.09 ng/mL, p= 0.004), and increased the perioperative survival by 9% (97.2% versus 88.5%), but the actuarial survival rates were not significantly different between the groups from 2 to 24 months (p= 0.151).

Conclusions

Both techniques (linear and patch) achieved good results with respect to mortality, functional status and survival. The choice of surgical technique should be adapted in each patient. The beating heart technique may to some extent relieve myocardial injury in patients undergoing SVR.

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.

Anisotropic reinforcement of acute anteroapical infarcts improves pump function

BACKGROUND

We hypothesize that a therapy that improves left ventricular (LV) pump function early after infarction should decrease the need for compensation through sympathetic activation and dilation, thereby reducing the risk of developing heart failure. The mechanical properties of healing myocardial infarcts are an important determinant of LV function, yet improving function by altering infarct properties has proven unexpectedly difficult. Using a computational model, we recently predicted that stiffening a large anterior infarct anisotropically (in only one direction) would improve LV function, whereas isotropic stiffening, the focus of previous studies and therapies, would not. The goal of this study was to test the novel strategy of anisotropic infarct reinforcement.

METHODS AND RESULTS

We tested the effects of anisotropic infarct reinforcement in 10 open-chest dogs with large anteroapical infarcts that depressed LV pump function. We measured regional mechanics, LV volumes, and cardiac output at a range of preloads at baseline, 45 minutes after coronary ligation (ischemia), and 30 minutes later, after surgical reinforcement in the longitudinal direction (anisotropic). Ischemia shifted the end-systolic pressure-volume relationship and cardiac output curves rightward, decreasing cardiac output at matched end-diastolic pressure by 44%. Anisotropic reinforcement significantly improved systolic function without impairing diastolic function, recovering half the deficit in overall LV function.

CONCLUSIONS

We conclude that anisotropic reinforcement is a promising new approach to improving LV function after a large myocardial infarction.

Off-pump plication of left ventricular aneurysm

With a small left ventricular aneurysm, the surgeon finds it difficult to decide whether to repair the aneurysm or leave it alone; there are risks and benefits to consider. Our choice is plication rather than resection. The procedure may be performed on-pump or off-pump, and the results are easy to demonstrate with the help of transesophageal echocardiogram.

Surgical ventricular restoration to reverse left ventricular remodeling

Heart failure is one of the major health care issues in the Western world. An increasing number of patients are affected, leading to a high rate of hospitalization and high costs. Even with administration of the best available medical treatment, mortality remains high. The increase in left ventricular volume after a myocardial infarction is a component of the remodeling process. Surgical Ventricular Restoration (SVR) has been introduced as an optional therapeutic strategy to reduce left ventricular volume and restore heart geometry. So far, it has been established that SVR improves cardiac function, clinical status, and survival in patients with ischemic, dilated cardiomyopathy and heart failure. Since its first description , SVR has been refined in an effort to standardize the procedure and to optimize the results. This review will discuss the rationale behind surgical reversal of LV remodeling, the SVR technique, its impact on cardiac function and survival, and future expectations.

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.

Long-term outcomes after surgical ventricular restoration and coronary artery bypass grafting in patients with postinfarction left ventricular anterior aneurysm

OBJECTIVE

Surgical ventricular restoration (SVR) for postinfarction left ventricular anterior aneurysm improves left ventricular function. The aim of this study was to evaluate whether concomitant multivessel coronary artery disease (MVCAD) can affect long-term outcome. Thus, long-term results of SVR associated with multiple coronary artery bypass grafting (CABG) for MVCAD (group 1) were compared with SVR with or without CABG to left anterior descending artery and/or its diagonal branch for single-vessel coronary artery disease (group 2).

METHODS

Data from 104 consecutive patients (age 64 +/- 8 years) with left ventricular anterior aneurysm, subjected to SVR from January 1994 to December 2004 and divided into group 1 (n = 79) and group 2 (n = 25), were analyzed.

RESULTS

In group 1 vs. group 2, number of grafts/patient (2.7 +/- 0.9 vs. 0.6 +/- 0.6, P < 0.0001) was higher, cardiopulmonary bypass (109 +/- 30 vs. 65 +/- 28 min, P < 0.0001) and aortic cross-clamp times (65 +/- 18 vs. 44 +/- 23 min, P < 0.0001) were longer, resected aneurysmatic area (12 +/- 8 vs. 17 +/- 11 cm2, P < 0.05) was smaller. Operative mortality was 3.7 vs. 4% (P = not significant). At 12 years, survival (85 +/- 5 vs. 80 +/- 16%) and freedom from cardiac events (70 +/- 7 vs. 75 +/- 16%) were not statistically different in both groups. Follow-up echocardiography showed significant left ventricular ejection fraction improvement in group 1 (0.45 +/- 0.07 vs. 0.34 +/- 0.10 preoperatively, P < 0.0001) and group 2 (0.47 +/- 0.09 vs. 0.36 +/- 0.12, P = 0.001). Independent predictors of late death were preoperative history of ventricular arrhythmias (P < 0.001) and hypo/akinesia of proximal myocardial anterior wall (P < 0.05).

CONCLUSION

Late survival and freedom from cardiac events are excellent after SVR, also when concomitant MVCAD requires complete revascularization. Ventricular arrhythmias and impaired left ventricular anterior wall function are predictors of worse outcome.

Surgical treatment of left ventricular aneurysm

When a left ventricular aneurysm leads to pulmonary congestive symptoms, aneurysmectomy may provide relief. This retrospective study included 269 patients who underwent aneurysmectomy between 1993 and 2002, by the classic Cooley operation in 164 and by Dor ventriculoplasty in 105. There were no significant differences in early and late survival between groups, although the frequency of extended anteroseptal infarction was higher in patients undergoing the Dor procedure. Postoperative echocardiographic findings showed significant improvements in left ventricular function in both groups, in terms of end-diastolic and end-systolic dimensions and ejection fraction. Left ventricular aneurysmectomy significantly improved the clinical status and hemodynamic parameters of symptomatic patients. The choice of surgical technique depends on the extent of the scar segment, especially the presence of an anteroseptal scarred area. The Dor procedure is more suitable for restoring normal left ventricular geometry in patients with extensive septal infarction.

Strategies for left ventricular assist device insertion after the Dor procedure

Insertion of the inflow cannula of an implantable left ventricular assist device (LVAD) is a surgical challenge in patients who have previously undergone a Dor ventriculoplasty procedure. We report a 54-year-old man who had successful LVAD insertion 18 months after a Dor procedure. We also describe the strategy of LVAD insertion in such patients.

Surgery for left ventricular aneurysm: is there still any role for simple linear repair?

The aim of left ventricular aneurysm (LVA) surgery is to eliminate the diskinetic portion of the left ventricle and to restore the patient's clinical condition. This can be obtained with two surgical procedures: linear repair and endoventricular patch technique. We investigated early- and long-term results in patients who underwent both procedures. From January 1980 to December 2004, 158 patients underwent surgical repair of LVA: 86 had linear repair and 72 patch repair. Operative mortality was 6.9%, with no differences between the two groups. Logistic regression revealed older age, higher left ventricular end-diastolic volume, and an ejection fraction (EF) less than 30% as independent risk factors for in-hospital mortality; the type of operation "per se" did not influence the early mortality. At the follow-up extending up to 25 years, there was no statistically significant difference in survival between the two study groups, as well as in New York Heart Association and Canadian Cardiovascular Society classes. Cox regression revealed older age, EF less than 30%, urgent operation, and a history of cerebrovascular accident as independent risk factors for late mortality: the type of operation did not influence mortality at follow-up. We conclude that aneurysm resection associated with myocardial revascularization is the best treatment for LVA. The choice of the technique should be tailored on an individual basis, according to aneurism location, extension, residual ventricular function, and septal involvement.

Hemodynamics at rest do not match clinical improvement after surgical ventricular restoration

OBJECTIVES

The aim was to study the change in cardiac index (CI) and pulmonary artery pressure (PAP) by intra-cardiac measurements after surgical ventricular restoration (SVR) in patients with left ventricular aneurysm and symptoms of heart failure. Aspects of functional improvement were analyzed as secondary outcomes.

DESIGN

Mean PAP and CI were obtained before and 6 months postoperatively in 22 patients who underwent SVR.

RESULTS

There were no significant changes in CI (2.3 vs. 2.4 L/min/m(2); p=0.91) or mean PAP (22 vs. 22 mmHg; p=0.64) at rest before and six months after surgery. Left ventricular ejection fraction improved from 25 to 38% (p<0.001). Before surgery 15 patients (68%) were in NYHA class III-IV and 6 months after the operation 19 (86%) patients were in NYHA class I-II (p<0.001).

CONCLUSIONS

Invasive hemodynamic measurements under resting conditions do not correspond well to the significant clinical improvement noted in these patients. Studies during exercise conditions are necessary to further evaluate this procedure.

Left Ventricular Reconstruction by Modified Linear Technique with Absorbable Suture

BACKGROUND

Linear and endoventricular techniques of left ventricular (LV) reconstruction often utilise prosthetic material for epicardial reinforcement or endocardial patch. We report a technique of LV aneurysm repair using absorbable suture without prosthetic material.

METHODS

Between November 1999 and August 2004, 55 patients underwent linear LV reconstruction, for ischaemic cardiomyopathy, using only continuous 3/0 polydioxanone suture. Survival, functional class and echocardiographic outcomes are reported.

RESULTS

Fifty-two patients (mean age 64+/-10 years) were studied. There was no perioperative mortality and the Kaplan-Meier survival at five years was 81%. Fifty-one patients underwent postoperative follow up (mean 28 months) with echocardiography (mean 20 months). There were no recurrent aneurysms. The postoperative LV eccentricity index (EI) was 0.72 (CI 0.48-0.9). Mean LV ejection fraction increased from 0.33+/-0.09 preoperatively to 0.41+/-0.15 at late follow up (mean within patient change 0.08+/-0.15, p=0.003). Mean symptom class improved from 3.3+/-0.8 to 1.6+/-0.7 (mean within patient improvement 1.6+/-1.0, p<0.001). Mitral regurgitation of grade 2/4 was identified in six patients and grade 3/4 in one patient.

CONCLUSION

Linear repair with absorbable suture material and without prosthetic material may be safely undertaken with good early and mid-term results.

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

OBJECTIVES

Surgical left ventricular reconstruction improves symptoms and potentially prognosis in patients with ischemic cardiomyopathy; however, the effects of reconstruction on myocardial mechanics are not well defined. Therefore, we have computed left ventricular rotation and torsion in patients undergoing left ventricular reconstruction to determine its effects on these quantitative measures of myocardial mechanics.

METHODS

Magnetic resonance imaging with tissue grid-tagging was performed in 26 patients (19 male/7 female, 62 +/- 11 years) (mean +/- standard deviation) before (23 +/- 29 days) and after (231 +/- 106 days) left ventricular reconstruction, as well as in 7 healthy volunteers (5 male/2 female, 34 +/- 7 years). Left ventricular rotation was computed at basal and apical short-axis levels; torsion was defined as the difference between apical and basal rotation.

RESULTS

Before left ventricular reconstruction, maximal apical rotation was significantly impaired relative to that of healthy volunteers (P = .001), although maximal basal rotation was preserved (P = .84). After reconstruction, maximal torsion did not change significantly: torsion was 6 degrees +/- 3 degrees both before and after reconstruction (P = .84). However, the rate of early diastolic untwist improved significantly after reconstruction (-18 degrees/s +/- 13 degrees/s vs -23 degrees/s +/- 14 degrees/s; P = .04). Furthermore, patients with relatively worse torsion before reconstruction demonstrated more improved function after reconstruction; patients with torsion of less than 6 degrees (n = 12) showed greater improvement in ejection fraction (15% vs 6%; P = .005), torsion (1 degrees vs -1 degrees; P = .01), and diastolic untwist (-9 degrees/s vs -25 degrees/s; P < .001) than did patients with torsion of 6 degrees or more (n = 14).

CONCLUSIONS

Torsional mechanics were severely impaired by ischemic cardiomyopathy. On average, left ventricular reconstruction did not affect systolic torsion generation significantly; however, patients with relatively worse torsion did show improvement. Furthermore, the rate of untwist improved after surgery, suggesting that diastolic function was improved.

Left ventricular restoration: how important is the surgical treatment of ischemic heart failure trial?

If the Surgical Treatment of Ischemic Heart Failure (STICH) trial demonstrates that surgical therapy is superior to medical therapy, early aggressive evaluation of coronary artery disease as a potentially correctable cause of new-onset heart failure would be the preferred strategy. This strategy could tremendously change the treatment of ischemic heart disease. Confirming the STICH revascularization hypothesis will dramatically increase the use of coronary artery bypass grafting among the millions of patients now being medically treated without evaluation for an ischemic cause.

Outcomes Following Surgical Ventricular Restoration in Elderly Patients With Congestive Heart Failure

Despite the well described benefits of surgical ventricular restoration (SVR) for patients with ischemic cardiomyopathy, the effects of advanced age on outcomes following this procedure have not been well documented. The authors compared outcomes in 69 consecutive patients 65 years and older (n=27) and younger than 65 years (n=42) to determine the utility of SVR in an elderly population with end-stage heart failure. Patients 65 years and older demonstrated significant improvements in ejection fraction (P=.01) and left ventricular end-systolic volume index (P=.07) following SVR, which were similar to the improvements seen in patients younger than 65 years. Sixty percent (15 of 25) of patients 65 years and older in preoperative New York Heart Association class III/IV improved to class I/II at follow-up (P<.0001). Actuarial survival was 68.8% at 2.5 years. Like their younger counterparts, elderly patients demonstrate significant improvements in ventricular function and NYHA class with acceptable survival following SVR.

Effect of passive cardiac containment on ventricular synchrony and cardiac function in awake dogs

OBJECTIVE

Passive restraint of the left ventricle (LV) has been shown to have beneficial effects on acute hemodynamics and reverse remodeling in both animal and human models. The goals of this study were to test whether a left ventricular support device (LVSD) improves LV synchrony and/or affects cardiac performance.

METHODS

Ten dogs were chronically instrumented to measure hemodynamics and LV volume (sonomicrometry). Congestive heart failure (CHF) was induced by repeated intracoronary microembolization via a chronically implanted coronary catheter. The LVSD was implanted after establishment of CHF in five animals, and five animals were observed as controls. All animals were then observed for 8 weeks. A mathematical model to measure LV synchrony was used to evaluate LV motion over time.

RESULTS

Mean arterial pressure and LV pressures was significantly increased after LVSD therapy, and LV pressure-volume relationships were shifted leftwards, although no change was seen in ejection fraction, end-systolic elastance, or LV dP/dt versus control. There was no significant change in diastolic function in LVSD animals compared with control animals. End-diastolic volumes were reduced by 15% after 8 weeks with LVSD treatment, versus an increase of 8% in control animals (p<0.05). Synchrony was significantly improved with LVSD therapy compared with control (9% vs 76% of baseline) in 1 of 11 ventricular dimension axes (Anterior-Apex).

CONCLUSIONS

LVSD therapy provided only minimal improvement in ventricular synchrony and partially improved hemodynamics. Further study into mechanisms of benefit are warranted.

Surgical Ventricular Restoration for Advanced Congestive Heart Failure: Should Pulmonary Hypertension Be a Contraindication?

BACKGROUND

Surgical ventricular restoration (SVR) is an established therapy for congestive heart failure due to ischemic cardiomyopathy. Pulmonary hypertension (PHTN) has been considered a contraindication for SVR owing to a presumed increase in operative risk. However, outcomes in these patients and the impact of SVR on PHTN have not been specifically evaluated.

METHODS

We retrospectively reviewed SVR patients between January 2002 and June 2005. Patients were classified as PHTN (mean pulmonary artery pressure > or = 25 mm Hg) and no PHTN (mPAP < 25 mm Hg) based on preoperative cardiac catheterization. Cardiac function was assessed using magnetic resonance imaging and echocardiography. Follow-up was 100%.

RESULTS

Sixty-nine patients underwent SVR for congestive heart failure. Thirty-six percent (25 of 69) had preoperative PHTN. Preoperatively, PHTN patients had significantly lower ejection fraction (21.1% versus 30.0%; p = 0.005) and larger left ventricular end-systolic volume index (119.0 versus 88.7 mL/m2; p = 0.04) than patients without PHTN. All PHTN patients and 95.5% (42 of 44) of the no PHTN group were New York Heart Association (NYHA) class III/IV preoperatively. There was 1 operative death in the PHTN group. Surgical ventricular restoration significantly improved cardiac function and pulmonary pressures for PHTN patients. Both groups had similar cardiac function postoperatively. Seventy-two percent (18 of 25) of PHTN patients and 69.0% (29 of 42) of patients without PHTN improved to NYHA class I/II at follow-up. Kaplan-Meier survival of PHTN patients was 68.1% at 3 years, which was lower than patients without PHTN (81.4%; p = 0.44), but not statistically significant. Kaplan-Meier 3-year survival for all SVR patients was 76.6%.

CONCLUSIONS

Surgical ventricular restoration is a good treatment option in patients with advanced congestive heart failure and PHTN. Our early results are promising and should prompt further studies to confirm these findings.

Improvement of cardiac sarcoplasmic reticulum calcium cycling in dogs with heart failure following long-term therapy with the Acorn Cardiac Support Device

Abnormal Ca(2+)-homeostasis is a hall-marked characteristic of the failing heart. In the normal myocardium, the sarcoplasmic reticulum (SR) is a principal organelle that controls intracellular Ca(2+) concentration during the cardiac cycle. The SR consists of longitudinal and terminal cisternea regions. The former contains the Ca(2+)-ATPase pump or SERCA-2a whose function is to transport cytosolic Ca(2+) into the lumen of the SR during diastole and whose activity is regulated by reversible phosphorylation of the endogenously SR-bound phospholamban (PLB). The SR's terminal cisternea region contains ryanodine-sensitive Ca(2+)-release channels (RR), the activity of which is regulated by direct and indirect reversible phosphorylation. These channels release the SR-stored Ca(2+) during contraction. We have shown that in left ventricular (LV) myocardium from dogs with coronary microembolization-induced heart failure, ability of the SR to sequester and release Ca(2+) during the cardiac cycles is impaired. This abnormality was associated with reduced expression (protein and mRNA) levels of Ca(2+)-ATPase, PLB, and reduced PLB phosphorylation. Long-term therapy with the Acorn Cardiac Support Device (CSD) is associated with restoration of the ability of the SR to sequester Ca(2+). This improvement in SR function following chronic CSD therapy was due primarily to increased affinity of the SERCA-2a for calcium. The later was associated with (1) increased phosphorylation of PLB at serine 16 and threonine 17, (2) unchanged protein expression of PLB and (3) unchanged protein expression of SERCA-2a in LV myocardium of CSD-treated dogs compared to controls. This review summarizes our current understanding of the role of the CSD in modulating SR calcium cycling in an experimental canine model of chronic heart failure produced by multiple sequential intracoronary microembolizations.

Reversal of maladaptive gene program in left ventricular myocardium of dogs with heart failure following long-term therapy with the Acorn Cardiac Support Device

Progressive left ventricular (LV) dilation is a characteristic feature of heart failure and is associated with poor long-term prognosis. One of the characteristic changes that occur in the failing heart is a change in gene expression wherein fetal genes that were turned off shortly after birth are re-activated in heart failure and may play a key role in the progressive worsening of the heart failure state. This review discusses reversal of maladaptive gene expression in dogs with chronic heart failure treated long-term with the Acorn Cardiac Support Device (CSD); a passive mechanical device designed to prevent progressive LV enlargement and to restore normal LV chamber geometry. Studies in our laboratories have shown that, in addition to preventing LV dilation and improving LV ejection fraction, long-term therapy with the CSD reverses the maladaptive gene program observed in LV myocardium of dogs with heart failure. Therapy with the CSD was associated with up-regulated mRNA expression for alpha-myosin heavy chain and down-regulated mRNA expression of A- and B- type natriuretic peptides, cytokines and favorably modulated cytoskeletal proteins. These findings provide an explanation for mechanisms that may be partly responsible for the improvement in LV systolic and diastolic function seen in dogs with heart failure after long-term CSD therapy.

Left ventricular volume and function after endoventricular patch plasty for dyskinetic anteroapical left ventricular aneurysm in sheep

OBJECTIVE

Endoventricular patch plasty (the Dor procedure) has gained favor as a surgical treatment for heart failure associated with large anteroapical myocardial infarction. We tested the hypothesis that the Dor procedure reduces left ventricular volume, increases end-systolic elastance, decreases diastolic compliance, and maintains left ventricular function.

METHODS

In 6 male Dorsett sheep, the left anterior descending coronary artery and its second diagonal branch were ligated 40% of the distance from apex to base. Sixteen weeks after myocardial infarction, a Dor procedure was performed with a Dacron patch that was 50% of the infarct neck dimension. Absolute left ventricular volume was measured with magnetic resonance imaging, and left ventricular pressure and relative left ventricular volume changes during pharmacologic preload reduction were measured with a volume conductance catheter 2 weeks before and 2 and 6 weeks after the Dor procedure. End-systolic elastance, diastolic compliance, and Starling relationships were calculated from the resultant left ventricular pressure/volume loops.

RESULTS

Two weeks after the Dor procedure, the left ventricular volume at end systole and end diastole was significantly reduced, and there was no redilation at 6 weeks. Six weeks after the Dor procedure, the ejection fraction was significantly increased. Although stroke volume increased slightly at 6 weeks, the change was not significant. The slopes of end-systolic elastance, diastolic compliance, and Starling relationships were unchanged at 2 and 6 weeks.

CONCLUSIONS

The Dor procedure significantly reduces left ventricular volume. Unlike linear repair, left ventricular volume changes seem stable. The ejection fraction is improved, and left ventricular function (stroke volume and the Starling relationship) is maintained.

Early and Mid-Term Results of Left Ventricular Volume Reduction Surgery for Dilated Cardiomyopathy

OBJECTIVE

To evaluate structure-oriented left ventricular volume reduction surgery (LVVRS). The purpose of this study was to report the early and mid-term results of left volume reduction surgery for dilated cardiomyopathy (DCM).

METHODS

We performed LVVRS on 29 patients with DCM. The age of the patient ranged from 8 to 73 years (mean 58 +/- 18 years). There were 19 male patients (63%). Twenty-three patients were ischemic, 5 were non-ischemic, and 1 had salcoidosis. Twenty-three patients were in New York Heart Association class III or IV. Fourteen patients underwent the Dor operation, 11 underwent a septal anterior ventricular exclusion operation, and 6 underwent a modified Batista operation. Fifteen patients underwent mitral annuloplasty and 2 patients had mitral valve replacement. All patients were divided into two groups, a Dor group (n = 14) and non-Dor group (n = 15). Postoperative early results and mid-term survival rate were compared between the two groups.

RESULTS

Hospital mortality was 13.8% (4/29). The causes of death were low-output syndrome (n = 3) and septic shock (n = 1). Survival rate was 80% at 1 year and 72% at 3 years. Two-year survival rate of Dor and non-Dor groups were 69.8% and 93.8%, respectively (p = 0.099).

CONCLUSIONS

Early and mid-term results of LVVRS were satisfied, and the non-Dor operation tended to be superior in mid-term survival to the Dor operation. Long-term follow-up is warranted.

Mechanical Synchrony: Role of Surgical Ventricular Restoration in Correcting LV Dyssynchrony During Chamber Rebuilding

Cardiac failure is frequently complicated by intra and or interventricular conduction delay that results in dyssynchronized cardiac contraction and relaxation. In contrast to an electrical intervention by biventricular pacing, this study tests the capacity of geometric rebuilding by surgical ventricular restoration (SVR) to restore a more synchronous contractile pattern through mechanical reconstruction without exogenous pacing input. Thirty patients (58 +/- 8 years) undergoing SVR at the Cardiothoracic Center of Monaco were prospectively evaluated with a protocol which uses simultaneous measurements of ventricular volumes and pressure to construct pressure/volume (P/V) and pressure/length (P/L) loops. Mean QRS duration was within normal limits (100 +/- 17 ms) preoperatively. Preoperative LV contraction was highly asynchronous. Endocardial time motion was either early or delayed at the end-systolic phase, yielding P/L loops with abnormal in size, shape, and orientation. Postoperatively, SVR resulted in leftward shifting of P/V loops and increased area; endocardial time motion and P/L loops almost normalized. The hemodynamic consequences of SVR included improved ejection fraction; reduced end-diastolic and end-systolic volume index; more rapid peak filling rate; peak ejection rate and mechanical efficiency resulting in mechanical intraventricular resynchronization that improves LV performance.

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

The left ventricular reconstruction (LVR) with endoventricular circular patch plasty (EVCPP) was reported in 1984 as a surgical method to rebuild left ventricular aneurysm or asynergy after myocardial infarction. Scarred LV wall can be dyskinetic or akinetic according to the type of infarction (transmural or not), and the progressive dilatation of LV (remodeling) depends on the size of the asynergic scar. Assessment of this extension and of LV volume and performances, is easy and reliable by magnetic resonance (CMR). The surgical technique is based on the insertion inside the ventricle on contractile myocardium, of a circular patch restoring curvature and physiological volume, and allowing exclusion of asynergic non resectable regions. The ventricular reconstruction method also has other components that include coronary revascularization (almost always), mitral repair (if needed) and endocardectomy when spontaneous or inducible ventricular tachycardia (VT) are present. The experience of the authors (> 1100 cases) and results obtained by other Centers, allows proposal of this technique as a way to treat the ischemic failing ventricle.

Absent Long-Term Benefit of Patch Versus Linear Reconstruction in Left Ventricular Aneurysm Surgery

BACKGROUND

Endoventricular patch reconstruction of the left ventricle is considered the gold standard in surgery for left ventricular aneurysms, because of improved preservation of ventricular geometry. However, the superiority over conventional linear closure has not been demonstrated, as assessed by the long-term outcome.

METHODS

Two hundred patients (66%) underwent linear closure (group L) and 105 patients (34%) had endoventricular patch reconstruction (group D) using the Dor technique. Linear closure has been performed since 1974 and from 1985 on the Dor technique has been applied as an alternative procedure. Both patient groups differed regarding age, sex distribution, site of infarction, and indication for surgery. Prior to the operation, 71% of the patients were in New York Heart Association (NYHA) class III or IV and mean ejection fraction was 34% +/- 12%. Follow-up extends up to 25 years, with a cumulative total of 2,605 patient years.

RESULTS

Early mortality was 6.5% in group L vs 5.7% in group D (not significant [NS]). Actuarial survival after 10 years was 56 +/- 3.2%, with no difference between groups. Freedom from reoperation after 10 years was 95.6% in group L vs 95.2% in group D (NS). Preoperative risk factors for late mortality were age, left ventricular enddiastolic volume index and concomitant mitral valve surgery. The type of procedure and the date of operation had no influence on mortality. To date, 63% of the survivors are in NYHA class I and II.

CONCLUSIONS

In regard to long-term survival, rate of reoperation, and postoperative NYHA functional class, no benefit could be demonstrated when linear closure was compared with ventricular patch reconstruction for LV aneurysm repair. Hence, the technique of ventricular reconstruction may not be as important as previously thought, and at least for small aneurysms the simple and time sparing technique of linear closure may still be considered.

Comparison of Volume Study by Left Ventriculography and Gated SPECT in Endoventricular Circular Patchplasty

Although quantitative gated SPECT (QGS) is widely used for left ventricular (LV) volume study, its accuracy is not established for those who have a large myocardial infarction scar or who had endoventricular circular patch plasty (EVCPP). Therefore, we compared LV volumes and LVEF calculated by QGS and those calculated by left ventriculography (LVG) before and after EVCPP. Sixteen patients (13 men and 3 women, mean age 67 +/- 9.5 years) were treated with EVCPP for postinfarction LV dyskinetic and/or akinetic scar. All patients were evaluated with both QGS and LVG before and after surgery. QGS was performed using eight frames per cardiac cycle, 1 hour after 740 MBq (99 m)Tc-tetrofosimin was administered. LVG images were acquired at a frame rate of 30 frames per second in the right anterior oblique 30-degree projection. We compared LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) between QGS and LVG. There was an excellent linear correlation between QGS and LVG in LVEDV (preoperative; r = 0.87, postoperative; r = 0.94), LVESV (preoperative; r = 0.95, postoperative; r = 0.89), and LVEF (preoperative; r = 0.73, postoperative; r = 0.81) before and after EVCPP. However, both preoperative LV volumes and postoperative LVEF calculated from QGS gave a smaller value than those calculated from LVG. Postoperative volume data by QGS was much close to LVG. The present study indicated that volume study by QGS is very useful to evaluate the LV function after EVCPP. However, we should pay attention to those facts.

Effects of cardiac support device on reverse remodeling: molecular, biochemical, and structural mechanisms

Progressive left ventricular (LV) dilation is a characteristic feature of heart failure and is invariably associated with poor long-term prognosis. This review discusses observations made in dogs with chronic heart failure using a passive mechanical containment device, the Acorn Cardiac Support Device (CSD), which is designed to prevent progressive LV enlargement. Studies have shown that, in addition to preventing LV dilation, long-term therapy with the CSD also improved LV ejection fraction, tended to normalize LV shape, reduced LV wall stress, and reduced or eliminated functional mitral regurgitation. At the cellular level, the CSD attenuates cardiomyocyte hypertrophy, reduced oxygen diffusion distance and downregulated stretch response proteins. The CSD also improved calcium cycling within the sarcoplasmic reticulum and upregulated mRNA gene expression for alpha-myosin heavy chain. These findings, when viewed in concert, provide an explanation for mechanisms that may be responsible for the improvement in LV function seen in dogs with heart after long-term CSD therapy.