Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation

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.

Surgical options of ischemic mitral regurgitation

Mitral regurgitation after a myocardial infarction is common. It can occur acutely or chronically, and its presence portends a poor prognosis. The focus of this article will be on chronic ischemic mitral regurgitation. We will discuss the current concepts of its pathophysiology, the benefits of revascularization, along with the surgical, and percutaneous therapeutic options.

Heart failure in the elderly: advances and challenges

The elderly population (age > or =65 years) is increasing, and with it the prevalence of heart failure and associated morbidity, hospitalizations and costs. Despite advances, clinical trial data on heart failure therapy exclusively for elderly patients are lacking. However, trials of therapy for heart failure with left ventricular systolic dysfunction or low ejection fraction in primarily non-elderly patients showed mortality benefit in elderly patients. By contrast, trials for heart failure with normal left ventricular systolic function or preserved ejection fraction have not shown mortality benefit in elderly or non-elderly patients. Heart failure pharmacotherapy in the elderly is challenging; it needs to be individualized and consider aging-specific changes in physiology, drug metabolism, drug pharmacokinetics and tolerance, comorbidities, polypharmacy and drug-drug interactions that can contribute to adverse effects. More research into the biology of aging and clinical trials in elderly patients may lead to the discovery of new therapies for heart failure in the elderly.

Microtopographical effects of natural scaffolding on cardiomyocyte function and arrhythmogenesis

A natural myocardial patch for heart regeneration derived from porcine urinary bladder matrix (UBM) was previously reported to outperform synthetic materials (Dacron and expanded polytetrafluoroethylene (ePTFE)) used in current surgical treatments. UBM, an extracellular matrix prepared from urinary bladder, has intricate three-dimensional architecture with two distinct sides: the luminal side with a smoother surface relief; and the abluminal side with a fine mesh of nano- and microfibers. This study tested the ability of this natural scaffold to support functional cardiomyocyte networks, and probed how the local microtopography and composition of the two sides affects cell function. Cardiomyocytes isolated from neonatal rats were seeded in vitro to form cardiac tissue onto luminal (L) or abluminal (Ab) UBM. Immunocytochemistry of contractile cardiac proteins demonstrated growth of cardiomyocyte networks with mature morphology on either side of UBM, but greater cell compactness was seen in L. Fluorescence-based imaging techniques were used to measure dynamic changes in intracellular calcium concentration upon electrical stimulation of L and Ab-grown cells. Functional differences in cardiac tissue grown on the two sides manifested themselves in faster calcium recovery (p<0.04) and greater hysteresis (difference in response to increasing and decreasing pacing rates) for L vs Ab side (p<0.03). These results suggest that surface differences may be leveraged to engineer the desired cardiomyocyte responses and highlight the potential of natural scaffolds for fostering heart repair.

End-systolic volume following surgical ventricular reconstruction impacts survival in patients with ischaemic dilated cardiomyopathy

AIMS

A left ventricular end-systolic volume (LVESV) > or =60 mL/m(2) has been shown to be associated with increased cardiac mortality after a reperfused myocardial infarction (MI). The reduction in LVESV following surgical ventricular reconstruction (SVR) is reported to be between 19% and 50% but its impact on prognosis is not well-established. The aim of this study was therefore to assess the impact on survival of a residual LVESV index (LVESVI) of > or = or <60 mL/m(2) following SVR.

METHODS AND RESULTS

All patients undergoing SVR at our Centre between July 2001 and March 2009 were eligible to be included in this study if they had a preoperative LVESVI of > or =60 mL/m(2) and an LVESVI measurement performed at discharge (7-10 days after surgery). Two hundred and sixteen patients (aged 64 +/- 9 years, 33 women) satisfied these criteria. Coronary artery bypass graft was performed in 197 patients (91.2%) and mitral repair in 63 patients (29%). Left ventricular ESVI had decreased by 41% at discharge in the overall population. Patients were grouped according to the residual LVESVI at discharge as follows: Group 1, LVESVI > or = 60 mL/m(2) (n = 71), and Group 2, LVESVI < 60 mL/m(2) (n = 145). In both groups, LVESVI decreased significantly with respect to baseline, by 29% in Group 1 and by 47% in Group 2. At multivariate analysis, the presence of a non-Q-wave MI and a preoperative internal diastolic diameter of 65 mm were the strongest predictors of a residual post-operative LVESVI of > or =60 mL/m(2). Risk of all-cause death was significantly higher in Group 1. Post-operative LVESVI of > or =60 mL/m(2) was an independent predictor of mortality at follow-up [Exp(B) = 10.7, CI: 2.67-42.9, P = 0.001].

CONCLUSION

Our findings confirm the role of LVESVI in predicting survival following SVR; the lack of additional improvement in survival with SVR observed in the STICH trial might be due to the inadequate volume reduction (-19%).

Quality of Life after 114 Months of Follow-up following Geometric Reconstruction of the Left Ventricle by Endoventriculoplasty with Septal Exclusion

Background: The purpose of this study was to present the surgical experience of the Institute of Cardiovascular Surgery of West of Paran (ICCOP) with respect to the treatment of left ventricle aneurysms by endoventriculoplasty with septal exclusion (EVSE) and to evaluate the quality of life of these patients after a 114-month follow-up.Methods: Between April 1999 and April 2006, 28 patients underwent EVSE. Preoperative, transoperative, and late postoperative clinical and echocardiographic variables were analyzed retrospectively. In addition, latepostoperative quality of life was evaluated with questionnaire SF-36 (Brazilian version). The mean age (SD) of the group was 59.0 9.5 years, and 23 of the patients were male. Seventeen patients were in New York Heart Association functional class IV, and the mean preoperative EuroSCORE was 8.2 2.3. The mean preoperative values for the ejection fraction (EF) and the end-systolic and end-diastolic left ventricular volumes were 32.3% 9.2%, 113.9 36.0 mL, and 179.2 48.4 mL, respectively.Results: The in-hospital mortality rate was 14.3%, with the major causes of morbidity being low cardiac output syndrome and arrhythmias. The mean follow-up period was 5.9 3.4 years. The left ventricular EF and the aortic cross-clamping time were the significant factors for hospital and late mortality (P = .0222, and P = .0123, respectively). The actuarial survival curve showed survival rates of 82.1 7.2%, and 54.7 22.9%, before and after 107 months of follow-up. The overall score for the quality of life showed an improvement.Conclusion: EVSE surgery is an effective option for treating this group of patients, with improvement noted in left ventricular function and in the patients' quality of life, despite the high in-hospital mortality.

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.

Left ventricular circumferential plication: novel off-pump ventricular restoration in swine model

We hypothesized that left ventricular (LV) and subvalvular geometries could be restored in a less invasive manner by circumferential plication without a ventriculotomy or a cardiopulmonary bypass (CPB). Continuous sutures were placed circumferentially on the epicardial surface of the LV wall without using a CPB in six healthy pigs. Coronary artery occlusion was precluded by placing the sutures underneath the peripheral coronary artery. After the circumferential sutures were plicated to 75% of the original length, hemodynamics were recorded and LV geometries and function were measured. All animals survived after plication without arrhythmia or hemodynamic deterioration. Angiogram findings demonstrated that plication reduced the LV end-diastolic volume (LVEDV) (72+/-10 vs. 58+/-12 ml, P<0.05), and sphericity (0.62+/-0.04 vs. 0.58+/-0.03, P<0.05). Also, three-dimensional echocardiography (3D-echo) showed that plication reduced the papillary muscle distance (27+/-3 vs. 18+/-2 mm, P<0.05). We demonstrated the effectiveness of off-pump circumferential plication, which reduced LV volume and altered subvalvular geometry without causing hemodynamic deterioration in an acute animal model. This pilot study suggests that our novel technique is feasible and should next be tested in a chronic model with a dilated failing heart, before clinical application is warranted.

Analysis of human myocardial dynamics using virtual markers based on magnetic resonance imaging

SUMMARY BACKGROUND

Myocardial dynamics are three-dimensional (3D) and time-varying. Cineradiography of surgically implanted makers in animals or patients is accurate for assessing these events, but this invasive method potentially alters myocardial motion. The aim of the study was to quantify myocardial motion using magnetic resonance imaging (MRI) and hence to provide a non-invasive approach to characterize 3D myocardial dynamics.

METHODS

Myocardial motion was quantified in ten normal volunteers by tracking the Lagrangian motion of individual points (i.e. virtual markers), based on time-resolved 3D phase-contrast MRI data and Fourier tracking. Nine points in the myocardium were tracked over the entire cardiac cycle, allowing a wire frame model to be generated and systolic and diastolic events identified.

RESULTS

Radius of curvature of the left ventricular (LV) wall was calculated from the virtual markers; the ratio between the anterior-posterior (AP) and septal-lateral (SL) walls in the LV shows an oval shape of the apical short axis plane at end systole (ES) and more circular at end diastole (ED). The AP/SL ratio for the basal plane shows an oval shape at ES and ED. We found that the rotation of the basal plane in ES was less compared to the apical plane [-2.0 +/- 2.2 versus 4.1 +/- 2.6 degrees (P<0.005)]. The apical plane rotated counter clock wise as viewed from the apex.

CONCLUSION

This new non-invasive tool, despite current limitations in temporal and spatial resolution, may provide a comprehensive set of virtual myocardial markers throughout the entire LV without the confounding effects introduced by surgical implantation.

Recent progress in heart failure treatment and heart transplantation

There has been significant progress in heart failure treatment; its stages are defined as a management platform for cardiovascular specialists. Surgical ventricular restoration adds no outcome advantage in ischemic heart failure over coronary artery bypass surgery alone. Novel medical therapies may include cytokine blockade and the vasodilator, relaxin. Although diastolic failure is prevalent, its clinical significance is unclear. Cardiac resynchronization reduces mortality and hospitalization. Perioperative enoximone facilitates beta-blockade for prophylaxis against myocardial ischemia. Heart failure still determines outcome in pulmonary embolism and cardiac surgery. The practice of ventricular assist devices continues to progress. A profile system based on urgency of mechanical support will guide future outcome assessment. Clinical scoring systems will guide the management of right heart failure. Device flow determines the risk of cerebral hyperperfusion and neurologic dysfunction. Regardless of device type, renal dysfunction remains an important outcome determinant. Postoperative heparinization is increasingly challenged because of the risks of bleeding and heparin-induced thrombocytopenia. The practice of heart transplantation continues to mature. The bicaval rather than the biatrial technique improves short-term outcome. Oral sildenafil is effective for pulmonary hypertension and right ventricular support. Although immunosuppression with tacrolimus is beneficial, sirolimus is less nephrotoxic and preserves coronary vasomotor function. The induction of immunosuppression may be modified as it has a weak evidence base. Psychosocial factors also continue to influence clinical outcome significantly. The future of heart failure treatment is bright with signs of active growth and progress in this vibrant subspecialty.

Surgical treatment for heart failure: left ventricular restoration for cardiomyopathy

Congestive heart failure has become a major problem and the only surgical treatment for end-stage heart failure caused by dilated cardiomyopathy (DCM) had been heart transplantation. However, because of the shortage of donors, several procedures for non-transplant surgery have been developed. Published literature on left ventricular (LV) restoration was searched to review the new surgical procedures for treating patients with ischemic or non-ischemic DCM. LV restoration was initiated in the 1980s for repairing LV aneurysm. In the 1990s several surgical procedures were introduced for treating DCM, and the new evolving surgical treatment plays an important role in the management of DCM in the 21st century.

Quality of life and economic outcomes with surgical ventricular reconstruction in ischemic heart failure: results from the Surgical Treatment for Ischemic Heart Failure trial

BACKGROUND

Surgical ventricular reconstruction (SVR) is used in conjunction with coronary artery bypass graft surgery (CABG) to improve left ventricular function and clinical outcomes in selected patients with ischemic heart failure. The impact of SVR on quality of life (QOL) and medical costs is unknown.

METHODS

We compared CABG plus SVR with CABG alone in 1,000 patients with ischemic heart failure, an anterior wall scar, and a left ventricular ejection fraction <or=0.35. In 991 (99% of eligible), we collected a battery of QOL instruments. The principal, prespecified QOL measure was the Kansas City Cardiomyopathy Questionnaire, which evaluates the effects of heart failure symptoms on QOL using a scale from 0 to 100 with higher scores indicating better QOL. Structured QOL interviews were conducted at baseline, 4, 12, 24, and 36 months post randomization and were >or=92% complete. Cost data were collected on 196 (98%) of 200 patients enrolled in the United States.

RESULTS

Heart-failure-related QOL outcomes did not differ between the 2 treatment strategies out to 3 years (median Kansas City Cardiomyopathy Questionnaire scores for CABG alone and CABG plus SVR, respectively: baseline 53 versus 54, P = .53; 3 years 85 versus 84, P = .89). There were no treatment-related differences in other QOL measures. In the US patients, total index hospitalization costs averaged over $14,500 higher for CABG plus SVR (P = .004) due primarily to 4.2 extra postoperative, high-intensity care days in the hospital.

CONCLUSIONS

Addition of SVR to CABG in patients with ischemic heart failure did not improve QOL but significantly increased health care costs.

Coronary bypass surgery with or without surgical ventricular reconstruction

BACKGROUND

Surgical ventricular reconstruction is a specific procedure designed to reduce left ventricular volume in patients with heart failure caused by coronary artery disease. We conducted a trial to address the question of whether surgical ventricular reconstruction added to coronary-artery bypass grafting (CABG) would decrease the rate of death or hospitalization for cardiac causes, as compared with CABG alone.

METHODS

Between September 2002 and January 2006, a total of 1000 patients with an ejection fraction of 35% or less, coronary artery disease that was amenable to CABG, and dominant anterior left ventricular dysfunction that was amenable to surgical ventricular reconstruction were randomly assigned to undergo either CABG alone (499 patients) or CABG with surgical ventricular reconstruction (501 patients). The primary outcome was a composite of death from any cause and hospitalization for cardiac causes. The median follow-up was 48 months.

RESULTS

Surgical ventricular reconstruction reduced the end-systolic volume index by 19%, as compared with a reduction of 6% with CABG alone. Cardiac symptoms and exercise tolerance improved from baseline to a similar degree in the two study groups. However, no significant difference was observed in the primary outcome, which occurred in 292 patients (59%) who were assigned to undergo CABG alone and in 289 patients (58%) who were assigned to undergo CABG with surgical ventricular reconstruction (hazard ratio for the combined approach, 0.99; 95% confidence interval, 0.84 to 1.17; P=0.90).

CONCLUSIONS

Adding surgical ventricular reconstruction to CABG reduced the left ventricular volume, as compared with CABG alone. However, this anatomical change was not associated with a greater improvement in symptoms or exercise tolerance or with a reduction in the rate of death or hospitalization for cardiac causes. (ClinicalTrials.gov number, NCT00023595.)

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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.

Effects of surgical ventricular restoration on left ventricular contractility assessed by a novel contractility index in patients with ischemic cardiomyopathy

A pressure-normalized left ventricular (LV) wall stress (dsigma*/dt(max)) was recently reported as a load-independent index of LV contractility. We hypothesized that this novel contractility index might demonstrate improvement in LV contractile function after surgical ventricular restoration (SVR) using magnetic resonance imaging. A retrospective analysis of magnetic resonance imaging data of 40 patients with ischemic cardiomyopathy who had undergone coronary artery bypass grafting with SVR was performed. LV volumes, ejection fraction, global systolic and diastolic sphericity, and dsigma*/dt(max) were calculated. After SVR, a decrease was found in end-diastolic and end-systolic volume indexes, whereas LV ejection fraction increased from 26% +/- 7% to 31% +/- 10% (p <0.001). LV mass index and peak normalized wall stress were decreased, whereas the sphericity index (SI) at end-diastole increased, indicating that the left ventricle became more spherical after SVR. LV contractility index dsigma*/dt(max) improvement (from 2.69 +/- 0.74 to 3.23 +/- 0.73 s(-1), p <0.001) was associated with shape change as evaluated by the difference in SI between diastole and systole (r = 0.32, p <0.001, preoperative; r = 0.23, p <0.001, postoperative), but not with baseline LV SI. In conclusion, SVR excludes akinetic LV segments and decreases LV wall stress. Despite an increase in sphericity, LV contractility, as determined by dsigma*/dt(max), actually improves. A complex interaction of LV maximal flow rate and LV mass may explain the improvement in LV contractility after SVR. Because dsigma*/dt(max) can be estimated from simple noninvasive measurements, this underscores its clinical utility for assessment of contractile function with therapeutic intervention.

Surgical ventricular restoration: left ventricular shape influence on cardiac function, clinical status, and survival

BACKGROUND

Myocardial infarction can result in a spectrum of left ventricular (LV) shape abnormalities. Surgical ventricular restoration (SVR) can be applied to any, but there are no data that relate its effectiveness to LV shape. Moreover, there is no consensus on the benefit of SVR in patients with a markedly dilated ventricle, without clear demarcation between scarred and normal tissue. This study describes postmyocardial infarction shape abnormalities and cardiac function, clinical status, and survival in patients undergoing SVR.

METHODS

Echo studies of 178 patients were retrospectively reviewed. Three types of LV shape abnormalities were identified: type 1 (true aneurysm), type 2 (nonaneurysmal lesions defined as intermediate cardiomyopathy), and type 3 (ischemic dilated cardiomyopathy).

RESULTS

SVR induced significant improvement in cardiac and clinical status in all patients, regardless LV shape types. Although not significant, mortality was higher in types 2 and 3.

CONCLUSIONS

Ischemic dilated cardiomyopathy and not just the true aneurysm can be successfully treated with SVR. Shape classification may be useful to improve patient selection and compare results from different institutions that are otherwise impossible to compare.

Surgical ventricular reconstruction in mice: elucidating potential targets for combined molecular/surgical intervention

OBJECTIVES

We hypothesize that persistent alterations in molecular signaling may drive recurrent pathologic remodeling even after the reduction of mechanical stress achieved via surgical ventricular reconstruction. We developed a murine model of surgical ventricular reconstruction that would facilitate molecular analysis of the postreconstruction myocardium and allow future exploitation of genetic models.

METHODS

C57/B6 mice underwent coronary artery ligation. For surgical ventricular reconstruction at 4 weeks after myocardial infarction, a purse-string suture (7-0 polypropylene) achieved at least partial exclusion of the apical aneurysm. Serial echocardiography was correlated to measurements of apoptosis and to Western blot analysis of key signaling cascades.

RESULTS

An immediate 21.7% +/- 2.6% improvement in fractional shortening was seen in the remaining myocardium after surgical ventricular reconstruction. Reduction in left ventricular volume and improved function persisted at 1 week, but recurrent dilatation at 4 weeks (left ventricular end-diastolic volume of 63.5 +/- 2.5 vs 42.1 +/- 5.4 microL immediately after reconstruction; P < .05) was associated with a loss of functional improvement (fractional shortening 41.2% +/- 2% vs 46% +/- 0.9%; P < .01). At 1 week after surgical ventricular reconstruction, there was a transient reduction in myocardial apoptosis. A steady reduction in cardioprotective myocardial Akt activation, however, was not affected by ventricular reconstruction.

CONCLUSION

This murine model recapitulates both the immediate benefits of surgical ventricular reconstruction and the longer-term recurrence of dilated cardiomyopathy seen previously in some animal models and human studies. Early analysis has begun to implicate persistent signaling changes in the postinfarction myocardium that may be responsible for recurrent dilatation after surgical ventricular reconstruction and that may become targets for combined surgical and molecular interventions.

Impact of surgical ventricular restoration on diastolic function: implications of shape and residual ventricular size

BACKGROUND

Limited data are available on left ventricle (LV) diastolic function in patients with ischemic dilated cardiomyopathy submitted to surgical ventricular restoration (SVR). The purpose of this study was to assess postoperative diastolic function changes and identify potential predictors of its worsening.

METHODS

One hundred and forty-six patients (65 +/- 9 years) with previous anterior myocardial infarction were evaluated before and after SVR. Hemodynamic and geometric parameters including the sphericity index and conicity index were measured. Diastolic function was explored using the transmitral flow velocity pattern, and four classes were defined: normal, abnormal relaxation, pseudonormal, and restrictive pattern. Diastolic function was defined as unchanged (no difference in diastolic pattern), improved (at least one class less), or worsened (at least one class more or, in the case of preoperative restrictive pattern, an early transmitral flow velocity to atrial flow velocity [E/A] ratio increase of at least 20%).

RESULTS

The filling pattern before SVR was normal in 7 patients (4.8%), abnormal relaxation in 99 (68%), pseudonormal in 28 (19%), and restrictive in 12 (8.2%). After SVR, the filling pattern was unchanged in 105 patients (72%), improved in 14 (9.6%), and worsened in 27 (18.4%). Based on the univariate analysis, the preoperative conicity index and the end-diastolic volume difference (the result of surgical volume reduction) were associated with a diastolic pattern worsening.

CONCLUSIONS

Diastolic function did not change or improve in the majority of patients. In the minority of patients who experienced worsening, this was associated with the preoperative LV shape and residual volume.

Oxidative stress and left ventricular remodelling after myocardial infarction

In acute myocardial infarction (MI), reactive oxygen species (ROS) are generated in the ischaemic myocardium especially after reperfusion. ROS directly injure the cell membrane and cause cell death. However, ROS also stimulate signal transduction to elaborate inflammatory cytokines, e.g. tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and -6, in the ischaemic region and surrounding myocardium as a host reaction. Inflammatory cytokines also regulate cell survival and cell death in the chain reaction with ROS. Both ROS and inflammatory cytokines are cardiodepressant mainly due to impairment of intracellular Ca(2+) homeostasis. Inflammatory cytokines stimulate apoptosis through a TNF-alpha receptor/caspase pathway, whereas Ca(2+) overload induced by extensive ROS generation causes necrosis through enhanced permeability of the mitochondrial membrane (mitochondrial permeability transition). Apoptosis signal-regulating kinase-1 (ASK1) is an ROS-sensitive, mitogen-activated protein kinase kinase kinase that is activated by many stress signals and can activate nuclear factor kappaB and other transcription factors. ASK1-deficient mice demonstrate that the ROS/ASK1 pathway is involved in necrotic as well as apoptotic cell death, indicating that ASK1 may be a therapeutic target to reduce left ventricular (LV) remodelling after MI. ROS and inflammatory cytokines activate matrix metalloproteinases which degrade extracellular matrix, causing a slippage of myofibrils and hence LV dilatation. Consequently, collagen deposition is increased and tissue repair is enhanced with myocardial fibrosis and angiogenesis. Since the extent of LV remodelling is a major predictor of prognosis of the patients with MI, the therapeutic approach to attenuating LV remodelling is critically important.

Ventricular Restoration by Linear Endoventricular Patchplasty and Linear Repair

Surgical ventricular restoration improves cardiac function in patients with large left ventricular aneurysms. Aneurysm repair techniques have evolved to geometric repair by exclusion of the aneurysmal area with a circular patch. But even circular endoventricular patchplasty may result in a less elliptical ventricle. We modified the techniques of both linear and geometric repair. The early and intermediate outcomes in 102 patients with post-infarction left ventricular aneurysm, treated between 2001 and 2004, were analyzed. Concomitant procedures included coronary artery bypass grafting in 73 patients, mitral valve repair in 29, cryoablation in 3, and post-infarction ventricular septal rupture repair in 3. Overall mortality was 12.7%. Left ventricular ejection fraction increased significantly postoperatively, from 31.5% ± 6.5% to 34.2% ± 5.9%. There were significant decreases in end-diastolic volumes from 140.3 ± 38.3 to 100.8 ± 33.5 mL, and end-systolic volumes from 95.1 ± 26.1 to 66.0 ± 21.7 mL. These benefits continued at the 12- to 52-month follow-up. Our modified technique restores a near physiological left ventricular geometry and has a favorable clinical outcome.

Impact of subvalvular procedure for ischemic mitral regurgitation on leaflet configuration, mobility, and recurrence

BACKGROUND

Procedures on the subvalvular apparatus are an etiology-based treatment for ischemic mitral regurgitation (IMR).

METHODS AND RESULTS

Fifty-nine patients with IMR were divided into 3 groups: mitral annuloplasty (MAP) (M group, n=27), MAP+left ventricular reconstruction (LVR) (LV group, n=18), and MAP+LVR+subvalvular procedure (S group, n=14). Tenting height and area, angle between the annular line and the line connecting leaflet base to the bending- or tip-point of either the anterior or posterior leaflet, and leaflet mobility were measured echocardiographically preoperatively and at immediate- and mid-term postoperative follow-up. The angles at the bending-point of the anterior leaflet in mid-systole remained greater than those at its tip-point in the M and LV groups, but became significantly smaller postoperatively only in the S group (p<0.05). Postoperative leaflet mobility at the bending-point in the S group became significantly greater than in the other groups (p<0.01). The grade of MR, after significant reduction by the procedure, increased again in the M and LV groups, but remained almost unchanged in the S group.

CONCLUSION

Subvalvular procedures improved the configuration and mobility of the anterior leaflet, and can be expected to reduce the recurrence of IMR.

Surgical therapies for post-myocardial infarction patients

Occasionally, high-risk patients in the post-myocardial infarction (MI) period require surgical intervention for stabilization and/or revascularization. In a meta-analysis involving 3,088 patients with ischemic heart disease, revascularization was associated with nearly an 80% reduction in the risk of death. Coronary artery bypass graft (CABG) surgery is commonly performed in post-MI patients and is associated with more favorable outcomes than medical therapy. However, several factors have to be considered in proper patient selection for CABG, such as the left ventricular ejection fraction (LVEF), severity of heart failure (HF), and myocardial viability. The ongoing Surgical Treatment for Ischemic Heart Failure (STICH) trial will assess the benefits of CABG in patients with both a low LVEF and HF. Unstable post-MI patients who fail revascularization can be managed via mechanical circulatory support devices or pumps. These options significantly improve hemodynamic parameters. In addition, other surgical techniques, such as mitral valve repair, ventricular reconstruction surgery, and atrial fibrillation ablation, are being evaluated in patients with ischemic heart disease.

Outcome of patients listed for heart transplantation after a failed surgical ventricular restoration procedure

Patients with end-stage ischemic cardiomyopathy (IHD) and left ventricular (LV) dilatation are increasingly treated by means of surgical ventricular restoration (SVR). In some patients, SVR can delay heart transplantation (HTX). We retrospectively analyzed our experience, trying to ascertain whether HTX after a failed SVR (fSVR) carried a greater mortality risk. Since 1985, we performed 742 HTX. Since June 1999, 133 IHD patients were listed for HTX. We assigned them to 3 groups: (A) not a redo (n=54); (B) redo after coronary artery bypass grafting (n=54); and (C) redo after fSVR (n=25). Respectively, 37, 33, and 12 patients underwent HTX with in-hospital mortality after HTX of 4/37 (10.8%), 12/33 (36.4%), and 2/12 (16.7%). Mortality on the list was 9/54 (16.7%), 11/54 (20.4%), and 7/25 (28.0%) respectively. Removal from the list occurred in 4, 5, and 2 patients, and 4, 5, and 4 patients are still awaiting HTX, respectively. In group C, the mean time from SVR to HTX list was 45.6+/-43.3 months, and list mortality occurred after 5.83+/-5.81 months. In-hospital mortality in both patients of group C was due to the occurrence of multisystem organ failure; 10/12 were extubated after 19.3+/-9.6 hours and discharged from the intensive care unit after 3.9+/-1.6 days. The recorded complications were: 3 acute renal failure, 1 pericardial effusion, and 2 episodes of acute rejection. Since only 5/25 patients with fSVR had undergone SVR at our institution, we cannot establish which patients were really eligible for HTX at the time of SVR. Our experience showed that patients listed for HTX displayed a high list mortality, but that HTX after a failed SVR did not seem to have a poorer outcome than HTX after previous conventional CABG.