Surgical Ventricular Remodeling Research Articles

The use of hemosorption in patients with dilated cardiomyopathy and severe heart failure as an alternative to surgical left ventricular remodeling

Background. Currently, about 40 million people in the world suffer from heart failure (HF). The development of severe HF is most often caused by dilated cardiomyopathy (DCM) that is a frequent indication for heart transplantation worldwide. Despite significant advances in the medical treatment of this pathology, the morbidity, hospitalization rates, and mortality are constantly increasing. This study aimed to evaluate the effectiveness of hemosorption in patients with severe HF on the background of DCM compared to surgical left ventricular remodeling. Materials and methods. The study is based on the results of a retrospective study that included 80 patients with severe HF on the background of DCM (NYHA III–IV). In group 1 (59 patients; left ventricular ejection fraction (LVEF) 21.10 ± 4.66 %), conservative medical therapy was supplemented with a course of 3 hemosorption procedures using granular deligandizing hemosorbent. In group 2 (21 patients; LVEF 22.40 ± 2.27 %), patients underwent surgical interventions in the form of LV remodeling. Results. There was a significant improvement in the clinical state and LV contractility in both groups. In group 1, LVEF increased by 12.90 ± 2.06 % (p < 0.01), in group 2 — by 13.25 ± 2.98 % (p < 0.05). Howe­ver, more complications, longer hospital stay, and higher morta­lity were associated with LV remodeling. Conclusions. The use of extracorporeal hemocorrection methods in the comprehensive treatment of patients with DCM can improve the clinical state of patients, treatment outcomes and avoid the risks associated with surgical interventions.

Effect of percutaneous pulmonary valve replacement on ventricular electrophysiological remodeling in a porcine model of repaired tetralogy of Fallot

Tetralogy of Fallot is the most common cyanotic congenital heart disease. Late after corrective surgery, patients are at risk of developing right ventricular (RV) failure due to pulmonary valve regurgitation and arrhythmias related to surgical scars and ventricular electrophysiological remodeling. Pulmonary valve replacement has been identified as an interesting strategy to reduce RV dilatation but its impact on the arrhythmic risk remains uncertain. We sought to determine whether percutaneous pulmonary valve implantation (PPVI) at an early pathological stage leads to benefical effects on right and left ventricular electrophysiological remodeling in a porcine model of repaired tetralogy of Fallot (rTOF). Piglets (<10 kg) underwent pulmonary artery banding, pulmonary valve disruption to induce RV hypertrophy and dilatation and a PTFE patch was sewn across the pulmonary annulus. Two-months later, PPVI was performed in a sub-group of rTOF pigs. At 3 months post-surgery, cardiac function was assessed by MRI in rTOF, rTOF-PPVI and Sham-operated pigs. Animals were euthanized and optical mapping of isolated left and right ventricles electrical activity was performed using the voltage-sensitive dye Di-4-ANEPPS. Expression of selected genes was assessed by quantitative RT-PCR. At 3 months post-surgery, pulmonary artery regurgitation, RV end-diastolic and end-systolic volumes normalized to body surface area were significantly increased in rTOF pigs compared to Sham animals. In rTOF-PPVI animals these parameters were partially reversed and not statistically different from Sham pigs. An action potential prolongation was observed in both the left ventricle and the RV epicardium but not in the endocardium of rTOF pigs. Within the RV epicardium, this prolongation was mainly confined to the anterior side. Interestingly, rTOF-PPVI pigs action potential durations were similar to Sham animals. In line with functional investigations, a large increase in BNP expression was found in rTOF RV compared to Sham pigs (fold change = 34) which was not as pronounced in rTOF-PPVi pigs (fold change = 3) while a lower expression of KCND3 and KCNJ2 was found in rTOF pigs. In our rTOF porcine model, PPVI at an early pathological stage reversed RV dilatation. It also successfully reversed action potential prolongation in the left ventricle and the anterior RV epicardium, and may thus have beneficial effects on the arrhythmic risk.

The pathophysiology of heart failure

Heart failure is a clinical syndrome that results when the heart is unable to provide sufficient blood flow to meet metabolic requirements or accommodate systemic venous return. This common condition affects over 5 million people in the United States at a cost of $10-38 billion per year. Heart failure results from injury to the myocardium from a variety of causes including ischemic heart disease, hypertension, and diabetes. Less common etiologies include cardiomyopathies, valvular disease, myocarditis, infections, systemic toxins, and cardiotoxic drugs. As the heart fails, patients develop symptoms which include dyspnea from pulmonary congestion, and peripheral edema and ascites from impaired venous return. Constitutional symptoms such as nausea, lack of appetite, and fatigue are also common. There are several compensatory mechanisms that occur as the failing heart attempts to maintain adequate function. These include increasing cardiac output via the Frank-Starling mechanism, increasing ventricular volume and wall thickness through ventricular remodeling, and maintaining tissue perfusion with augmented mean arterial pressure through activation of neurohormonal systems. Although initially beneficial in the early stages of heart failure, all of these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Treatment strategies have been developed based upon the understanding of these compensatory mechanisms. Medical therapy includes diuresis, suppression of the overactive neurohormonal systems, and augmentation of contractility. Surgical options include ventricular resynchronization therapy, surgical ventricular remodeling, ventricular assist device implantation, and heart transplantation. Despite significant understanding of the underlying pathophysiological mechanisms in heart failure, this disease causes significant morbidity and carries a 50% 5-year mortality.

Comparison of the Young-Laplace Law and Finite Element Based Calculation of Ventricular Wall Stress: Implications for Postinfarct and Surgical Ventricular Remodeling

Both the Young-Laplace law and finite element (FE) based methods have been used to calculate left ventricular wall stress. We tested the hypothesis that the Young-Laplace law is able to reproduce results obtained with the FE method. Magnetic resonance imaging scans with noninvasive tags were used to calculate three-dimensional myocardial strain in 5 sheep 16 weeks after anteroapical myocardial infarction, and in 1 of those sheep 6 weeks after a Dor procedure. Animal-specific FE models were created from the remaining 5 animals using magnetic resonance images obtained at early diastolic filling. The FE-based stress in the fiber, cross-fiber, and circumferential directions was calculated and compared to stress calculated with the assumption that wall thickness is very much less than the radius of curvature (Young-Laplace law), and without that assumption (modified Laplace). First, circumferential stress calculated with the modified Laplace law is closer to results obtained with the FE method than stress calculated with the Young-Laplace law. However, there are pronounced regional differences, with the largest difference between modified Laplace and FE occurring in the inner and outer layers of the infarct borderzone. Also, stress calculated with the modified Laplace is very different than stress in the fiber and cross-fiber direction calculated with FE. As a consequence, the modified Laplace law is inaccurate when used to calculate the effect of the Dor procedure on regional ventricular stress. The FE method is necessary to determine stress in the left ventricle with postinfarct and surgical ventricular remodeling.

Surgical left ventricular remodeling leads to better long-term survival and exercise tolerance than coronary artery bypass grafting alone in patients with moderate ischemic cardiomyopathy

Optimal treatment strategies for patients with ischemic cardiomyopathy and moderately reduced left ventricular function remain controversial. We assessed the early and midterm outcomes after surgical revascularization alone versus revascularization and additional left ventricular remodeling in these patients. Between 2000 and 2003, 285 consecutive patients with coronary artery disease and moderately impaired left ventricular function (ejection fraction 30%-40%) were surgically treated with coronary artery bypass grafting alone (group 1, n = 165) or open left ventricular remodeling in addition to revascularization (group 2, n = 120). Preoperatively, the New York Heart Association class, left ventricular ejection fraction, and end-diastolic diameter were comparable. Early and midterm outcomes, hemodynamic performance, and quality of life assessed by Minnesota Quality of Life Questionnaire were evaluated during a mean follow-up period of 70 months. Group 2 patients demonstrated significantly longer ventilation times, higher blood loss, and need for blood transfusion but had significantly lower operative mortality (4.5% compared with 8.5% in group 1). Seven-year follow-up demonstrated survival of 74.3% +/- 8.1% in group 1 versus 84.2% +/- 5.4% in group 2 (P < .05). Follow-up examinations revealed greater improvement of functional class in group 1 with mean 1.7 +/- 0.7 versus 2.03 +/- 0.8 in group 2 (P < .05). Cardiac-related hospital readmissions were comparable (3.8% vs 4.1%, P = .73). Patients with ischemic cardiomyopathy, in whom surgical ventricular remodeling was possible and performed, experienced more perioperative complications but had superior early and midterm outcome regarding survival, functional class, and quality of life.

Elective Bridging to Recovery After Repair: The Surgical Approach to Ventricular Reverse Remodeling

We described our "surgical approach to reverse ventricular remodeling" in advanced chronic heart failure, based on the unique idea that "downstaging" class IV heart failure by supporting patients with left ventricular assist devices (LVADs) allows treatments mainly indicated for class III patients. The types of surgeries include mitral valve repair, surgical ventricular remodeling, coronary artery bypass grafting, and cardiac resynchronization. This approach has been applied to two patients with class IV chronic heart failure due to idiopathic dilated cardiomyopathy who were supported with the magnetically levitated Levacor LVAD. These were the first in-human implantations of this device. Sustained short- to medium-term recovery has been achieved in both patients.

Surgical Ventricular Restoration Versus Cardiac Transplantation: A Comparison of Cost, Outcomes, and Survival

Background Cardiac transplantation is the accepted standard treatment for end-stage heart disease but is donor limited. Surgical ventricular remodeling is an established treatment for patients with ischemic cardiomyopathy. We sought to compare charges, outcomes, and survival in patients undergoing surgical ventricular restoration (SVR) versus cardiac transplantation (CTx). Methods and Results We retrospectively analyzed hospital charges, length of stay (LOS), and survival for 69 SVR and 53 CTx patients at our institution between January 2002 and June 2005. We also compared New York Heart Association (NYHA) status and Kaplan-Meier survival of our SVR patients with CTx patients with ischemic cardiomyopathy from the International Society of Heart & Lung Transplantation (ISHLT) registry. Median total LOS (12 days vs. 17 days, P = .01) and median postoperative LOS (10 days vs. 15 days, P = .02) were shorter for SVR patients than our CTx patients. Median total hospital charges ($45,506 vs. $137,679, P < .0001) and median total drug charges ($2,625 vs. $15,930, P < .0001) were lower for SVR patients. Significant improvements in ejection fraction were seen after both SVR (27% vs. 37%; P < .0001) and CTx (14% vs. 62%, P < .0001). Furthermore, 91% (49/54) of surviving SVR patients, 98% (44/45) of surviving CTx patients, and 91% of ISHLT CTx patients improved to NYHA Class I/II at follow-up. Survival did not differ between groups. Conclusions SVR patients demonstrate cost-effective clinical improvements that lead to good overall survival. SVR is an excellent surgical option for CHF patients who are not transplant candidates, and should be considered for ischemic cardiomyopathy patients who qualify for transplantation. This strategy may help relieve donor shortage and improve allocation of donor organs.

Surgical ventricular reverse remodeling in severe ischemic dilated cardiomyopathy: The relevance of the left ventricular equator as a prognostic factor

Surgical ventricular reverse remodeling in severe ischemic dilated cardiomyopathy: The relevance of the left ventricular equator as a prognostic factor

Surgical Ventricular Remodeling for Patients with Clinically Advanced Congestive Heart Failure and Severe Left Ventricular Dysfunction

Surgical Ventricular Remodeling for Patients with Clinically Advanced Congestive Heart Failure and Severe Left Ventricular Dysfunction

Surgical ventricular reverse remodeling in severe ischemic dilated cardiomyopathy: The relevance of the left ventricular equator as a prognostic factor

Surgical ventricular reverse remodeling has been shown to possibly improve hemodynamics and symptoms, but effects on long-term mortality are not established. No consistent data are available on which patients will benefit most from this procedure. This study was designed to analyze the predictors of long-term survival after surgical ventricular reverse remodeling in patients with ischemic cardiomyopathy. Eighty-five patients who underwent surgical ventricular reverse remodeling between May 1991 and October 2003 were retrospectively analyzed. Left ventricular wall motion and left ventricular equatorial diameter were assessed by means of angioventriculography. Left ventricular ejection fraction and volumes were measured by means of echocardiography. Cox regression analysis was used in several combinations to create a final model for identifying predictors of death. Actuarial survival after 1, 3, 5, and 10 years was 89%, 79%, 75%, and 75%, respectively. New York Heart Association class improved from 2.9 +/- 1.0 to 1.3 +/- 0.5 (P < .0001), left ventricular ejection fraction increased from 27.6% +/- 6.3% to 43.0% +/- 10.1% (P < .0001), and left ventricular end-systolic volume index decreased from 89.6 +/- 27.6 mL/m2 to 56.5 +/- 34.5 mL/m2 (P < .0001). Multivariate analysis identified left ventricular equatorial diameter of 70 mm or greater (hazard ratio, 5.28; 95% confidence interval, 1.79-11.71; P = .020) and segmental akinesia (hazard ratio, 4.46; 95% confidence interval, 1.23-17.12; P = .024) as the only independent predictors of death. In this analysis of a single cohort of patients, surgical ventricular reverse remodeling improves the symptoms of ischemic cardiomyopathy, as well as left ventricular function, shape, and volume, with encouraging long-term outcomes, particularly in patients with dyskinesia. A left ventricular equatorial diameter of 70 mm or greater appears to be an important independent prognostic factor, which suggests the relevance of the left ventricular equatorial region for effective surgical reverse remodeling.

Surgical ventricular remodeling for multiterritory myocardial infarction: Defining a new patient population

Because of limited medical and surgical options for patients with end-stage congestive heart failure, we expanded the criteria for surgical ventricular remodeling to include patients with multiterritory myocardial infarction, a group historically considered high-risk candidates. We present our series of patients with multiterritory myocardial infarction who underwent surgical ventricular remodeling and propose a new patient population who may benefit from this procedure. Data were analyzed for 51 consecutive patients undergoing surgical ventricular remodeling from January 2002 to June 2004, with 100% follow-up. Three left ventricular vascular territories were defined: anteroapicoseptal (left anterior descending), lateral (circumflex), and inferior (right coronary artery). Infarction was assessed with magnetic resonance imaging and intraoperative findings. Multiterritory myocardial infarction was found in 64.7% of patients (33/51) undergoing surgical ventricular remodeling. Mean age was 61.6 +/- 11.1 years (range 40-81 years). Sixty-one percent (20/33) demonstrated evidence of myocardial infarction in all three territories. Five patients underwent concomitant mitral valve repair or replacement. Operative mortality was 6.1% (2/33) and did not differ from that of patients with single-territory infarction (11.1%, P = .61). Surgical ventricular remodeling significantly improved left ventricular volumes and ejection fraction in patients with multiterritory myocardial infarction. Three patients required assist device implantation, and 2 patients required defibrillator placement. Sixty-nine percent of patients in preoperative New York Heart Association functional class III or IV (22/32) had improvement to class I or II at follow-up (P < .01). Cox regression analysis discriminated a preoperative left ventricular end-systolic volume index greater than 100 mL/m(2) as a significant risk factor for mortality (odds ratio 12.1, 95% confidence interval 1.27-114.51, P = .03). Thirty-month survival of patients with multiterritory myocardial infarction (73.5% +/- 8.3%) did not differ statistically from that of patients with single-territory infarction (n = 18). Surgical ventricular remodeling improves cardiac function and New York Heart Association functional status in patients with multiterritory myocardial infarction. Our initial results are promising and should prompt further studies to confirm our results and potentially expand the surgical ventricular remodeling inclusion criteria to include patients with multiterritory myocardial infarction.

Surgical Ventricular Remodeling for Patients with Clinically Advanced Congestive Heart Failure and Severe Left Ventricular Dysfunction

Surgical ventricular remodeling (SVR) is an accepted therapy for post-infarction ventricular remodeling. Current literature on SVR outcomes has focused on heterogeneous populations with regard to left ventricular function and New York Heart Association (NYHA) class. We assessed outcomes after SVR in patients with advanced congestive heart failure (CHF) (NYHA Class III/IV) and a pre-operative ejection fraction (EF) < or =20%. Data were analyzed for 51 consecutive SVR patients from January 2002 to June 2004. Cardiac catheterization, echocardiography and magnetic resonance imaging (MRI) identified 62.7% (32 of 51) of patients with an EF < or =20%, with the majority having an EF < or =15% (65.6%; 21 of 32). Cox regression analysis was performed to determine predictors of mortality in patients with an EF < or =20%. Follow-up was 100% (32 of 32) complete. Mean age was 61.9 +/- 10.3 (range 40 to 80) years with a male:female ratio of 27:5. Operative mortality was 6.3% (2 of 32). Twenty-two percent (7 of 32) had concomitant mitral valve procedures. Follow-up demonstrated a statistically significant improvement in left ventricular volumes and EF in survivors. Cox regression analysis identified the following to be significant predictors of mortality: pre-operative left ventricular end-systolic volume index >130 ml/m2; pre-operative diabetes; and intra-aortic balloon pump usage. Pre-operatively, all patients (32 of 32) were categorized as NYHA Class III/IV, with 69% (22 of 32) improving to NYHA Class I/II at follow-up (p < 0.01). Survival did not differ statistically between patients with an EF < or =20% and an EF >20% (n = 19). Our results indicate that SVR improves left ventricular function and functional status for patients with advanced CHF and a pre-operative EF < or =20%. Therefore, SVR is a viable surgical alternative for patients with severe left ventricular dysfunction.

Surgical left ventricular remodeling in heart failure

The high mortality and morbidity of patients in terminal heart failure are a therapeutic challenge to modern medicine. Surgically, cardiac transplantation is an excellent treatment for many patients. However, lack of donors combined with an increasing number of patients has led to the search for other surgical strategies. Patients with symptomatic large left ventricular aneurysms have been treated with resection of the aneurysm and closure of the left ventricle either directly (linear closure, first reported by Cooley) or by implantation of a patch (endoventricular patch plasty or Dor procedure). Akinetic areas of the left ventricle have also been successfully treated by the latter method. According to the law of Laplace, large dilated ventricles have increased wall tension and thus increased oxygen consumption. Based on this fact, Batista and coworkers have reduced the volume of enlarged left ventricles in patients in terminal heart failure by removing a wedge of myocardium from the apex of the heart towards the base of the left ventricular free wall. Although a favorable outcome has been reported in selected patients, this method is currently not recommended for treatment of heart failure because of high surgical failure rates. The present paper reviews some of the relevant literature regarding surgical left ventricular remodeling in heart failure. Two new techniques (Myosplint and CorCap cardiac support device) are also briefly described.

Surgical ventricular remodeling for severe left ventricular dysfunction (EF≤20%)

Surgical ventricular remodeling (SVR) is an accepted therapy for end-stage congestive heart failure. Surgical options are limited for patients (pts) with severe left ventricular dysfunction. We assessed outcomes of SVR in pts with preoperative ejection fraction (EF) ≤20%.

Two-chamber contractile silhouette predicts severity of pre-operative hemodynamics in patients undergoing trisvr surgery

Surgical left ventricular (LV) remodeling (TRISVR) is a procedure that both reduces LV volume and restores an elliptical LV endoventricular shape in patients with ischemic cardiomyopathy and low ejection fraction. Analysis of preoperative (pre-op) RAO 30° LV angiographic silhouettes has value in the selection of patients for TRISVR surgery. This report correlates pre-op contractile silhouette Types I-III with pre-op hemodynamic measurements affecting TRISVR surgical risk.Two-chamber LV contractile silhouette types describe residual regional LV chamber contractile function by identifying remaining contractile areas. The above three types of silhouettes uniquely described 61 of 68 consecutive patients undergoing TRISVR surgery. Patients underwent pre-op cardiac catheterization and transthoracic echocardiography with assessment of chamber volume, mean pulmonary artery pressure (PAP), mean pulmonary capillary pressure (Pcw), contractile EF% (regional EF% of most contractile areas), chamber EF%, and the presence and severity of mitral regurgitation (MR).

Editorial: Is mitral valvuloplasty always indicated in patients with poor left ventricular function and ischemic cardiomyopathy?

I n this issue of the Journal [J Thorac Cardiovasc Surg 2001;121:91-6], Di Donato and colleagues present 1-year follow-up data in 44 patients who underwent the Dor procedure. They found that deterioration of mitral valve function was more frequent in patients with larger preoperative ventricular volumes and decreased eccentricity indexes (increased sphericity) preoperatively. The issue of what to do for mitral regurgitation (MR) associated with left ventricular (LV) dilatation in patients with a low ejection fraction is a very important one. Dr Di Donato and colleagues have attempted to link MR after the Dor procedure with changes in ventricular shape and volume. The strength of their approach is that they have serial angiograms (preoperative, early, and 1-year postoperative studies) in many of their patients. The disadvantage, however, is that they have assessed MR by analyzing the ventriculograms. This is a rather insensitive method for detecting MR, especially in patients who have a dilated heart. Use of Doppler echocardiography would have given much more accurate information with regard to valve function. My colleagues and I have been surprised to find significant MR on preoperative echocardiographic evaluation in 45% of patients accepted for aneurysm repair who had no MR obvious on the ventriculogram.1 In many of these patients, ventricular remodeling and revascularization alone significantly improved mitral valve function postoperatively. This approach was associated with good symptomatic improvement and excellent 5-year survival in our series. I believe a word of caution is needed in properly interpreting the results reported by Di Donato and colleagues and in evaluating their conclusions. In their series, at 1 year, half of the patients with MR had only minor MR (grade 1). It is not clear to me that grade 1 MR will necessarily translate into a poor clinical result or decreased survival. I agree with Di Donato’s group that after myocardial infarction, preoperative MR and marked LV dilatation probably indicate more extensive adverse ventricular remodeling, which would have a negative impact on long-term results. I also agree that their observations support the argument for earlier surgical intervention in these patients. However, whether the addition of a valvuloplasty procedure is indicated in all patients with preoperative MR undergoing aneurysm repair requires further study. The relationship between MR and changes in ventricular shape and size remain complex and poorly understood. For example, Di Donato and colleagues have demonstrated that the diastolic shape of the ventricle became more spherical after the Dor procedure, yet systolic function appeared to improve. The impact of changes in ventricular size and shape after surgical ventricular remodeling on functional result and long-term survival are still to be established. Further studies are needed before definite recommendations can be made about case selection and optimal surgical technique for LV remodeling with or without mitral valve repair.

Immediate effects of partial left ventriculectomy on left ventricular function.

Attempts to prolong life or to improve the quality of life by partial left ventriculectomy in patients suffering from dilated cardiomyopathy have yielded strikingly variable results in leading surgical centers. The outcome of patients after partial left ventriculectomy depends on intraoperative myocardial protection together with appropriate long-term pharmacotherapy. We further assume that partial removal of the fibrotic ventricular wall may lead to a particularly inhomogeneous pattern of wall stress, giving rise to the potential of a paradoxical increase in wall stress and the creation of arrhythmogenic foci. During surgery in 24 patients, local mesh tension was measured using needle-force probes in up to five sites within the left ventricular wall before and after resection of the interpapillary mural segment. The data were used to calculate regional peak developed force and to identify any differences in the timing of local mechanical activity between the measured regions. Mean decrease in regional wall stress was 42% (76 sites of measurement). However, we discovered a paradoxical increase of 42% in 18 sites of measurement. The time delay in the onset of force development between the measured regions prior to surgery was 0 msec in 10 patients, up to 30 msec in 7 patients, and beyond 80 msec in 7 patients. After resection, the time delay increased considerably in incidence and duration. Ventriculectomy is an effective means of reducing wall stress. The unexpectedly high incidence of inhomogeneities in wall stress after asymmetrical surgical ventricular remodeling, currently typical for the classical Batista procedure, together with the asynchronous regional ventricular function that we found to increase after partial left ventriculectomy, needs further elucidation by electrophysiological investigations.