Coronary bypass surgery with or without surgical ventricular reconstruction

Chronic heart failure: contemporary diagnosis and management

Chronic heart failure (CHF) remains the only cardiovascular disease with an increasing hospitalization burden and an ongoing drain on health care expenditures. The prevalence of CHF increases with advancing life span, with diastolic heart failure predominating in the elderly population. Primary prevention of coronary artery disease and risk factor management via aggressive blood pressure control are central in preventing new occurrences of left ventricular dysfunction. Optimal therapy for CHF involves identification and correction of potentially reversible precipitants, target-dose titration of medical therapy, and management of hospitalizations for decompensation. The etiological phenotype, absolute decrease in left ventricular ejection fraction and a widening of QRS duration on electrocardiography, is commonly used to identify patients at increased risk of progression of heart failure and sudden death who may benefit from prophylactic implantable cardioverter-defibrillator placement with or without cardiac resynchronization therapy. Patients who transition to advanced stages of disease despite optimal traditional medical and device therapy may be candidates for hemodynamically directed approaches such as a left ventricular assist device; in selected cases, listing for cardiac transplant may be warranted.

Noninvasive estimation of left ventricular filling pressures in patients with heart failure after surgical ventricular restoration and restrictive mitral annuloplasty

OBJECTIVE

Doppler echocardiography, including tissue Doppler imaging, is widely applied to assess diastolic left ventricular function using early transmitral flow velocity combined with mitral annular velocity as a noninvasive estimate of left ventricular filling pressures. However, the accuracy of early transmitral flow velocity/mitral annular velocity in patients with heart failure, particularly after extensive cardiac surgery, is debated. Global diastolic strain rate during isovolumic relaxation obtained with 2-dimensional speckle-tracking analysis was recently proposed as an alternative approach to estimate left ventricular filling pressures.

METHODS

We analyzed diastolic function in patients with heart failure after surgical ventricular restoration and/or restrictive mitral annuloplasty. Echocardiography, including tissue Doppler imaging and speckle-tracking analysis, was performed to determine early transmitral flow velocity/atrial transmitral flow velocity, isovolumetric relaxation time, deceleration time, early transmitral flow velocity/mean mitral annular velocity, strain rate during isovolumic relaxation, and early transmitral flow velocity/strain rate during isovolumic relaxation. These noninvasive indices were correlated with relaxation time constant Tau, peak rate of pressure decline, and left ventricular end-diastolic pressure obtained in the catheterization room using high-fidelity pressure catheters.

RESULTS

Twenty-three patients were analyzed 6 months after restrictive mitral annuloplasty (n = 8), surgical ventricular restoration (n = 4), or a combined procedure (n = 11). The strongest correlation with invasive indices, in particular left ventricular end-diastolic pressure, was found for strain rate during isovolumic relaxation (r = -0.76, P < .001). Early transmitral flow velocity/mean mitral annular velocity did not correlate significantly with any of the invasive indices. Strain rate during isovolumic relaxation (cutoff value < 0.38 s(-1)) accurately predicted left ventricular end-diastolic pressure of 16 mm Hg or more with 100% sensitivity and 93% specificity.

CONCLUSIONS

In a group of patients with heart failure who were investigated 6 months after cardiac surgery, early transmitral flow velocity/mean mitral annular velocity correlated poorly with invasively obtained diastolic indexes. Global strain rate during isovolumic relaxation, however, correlated well with left ventricular end-diastolic pressure and peak rate of pressure decline. Our data suggest that global strain rate during isovolumic relaxation is a promising noninvasive index to assess left ventricular filling pressures in patients with heart failure after extensive cardiac surgery, including restrictive mitral annuloplasty and surgical ventricular restoration.

'Let's twist again': surgically induced renewal of left ventricular torsion in ischemic cardiomyopathy

OBJECTIVES

To test the potential of the heart to be surgically restored at a near-normal global condition, granted that its physiological characteristics are respected (working volumes, chamber geometry, fiber orientation, opposite rotation of apex and base, global torsion and strain).

METHODS

From May 2007 to December 2008, 12 consecutive patients with ischemic cardiomyopathy were included in this study. All patients underwent modified surgical anterior ventricular restoration combined with complete coronary revascularization and, when indicated, mitral anuloplasty. The modified restoration aims to re-approach residual myocardium, redirecting fiber orientation displaced by infarct scar toward a more physiological gross disposition. Patients were studied preoperatively and postoperatively with a complete echocardiographical assessment, including speckle-tracking analysis.

RESULTS

Standard parameters significantly improved after the operation (end diastolic volume, P < 0.001; end systolic volume, P < 0.001; ejection fraction, P = 0.004), and so did peak systolic apical rotation, peak systolic left ventricular torsion and two-chamber and four-chamber longitudinal strain (P = 0.004, 0.003, 0.05 and 0.01, respectively). Pearson's correlation between apical rotation and longitudinal strain (two-chamber and four-chamber) was -0.877 (P < 0.001) and -0.720 (P = 0.008), respectively, and between torsion and longitudinal strain was -0.845 (P = 0.001) and -0.785 (P = 0.002), respectively.

CONCLUSION

This study reveals an unexpected potential of the myocardium to be restored at a near-normal global condition, with regard to all of its physiological characteristics. The concept of fiber-based surgical treatment, supported by an imaging-guided preoperative study, could widen the potential of repairing a failing heart.

Impact of preoperative positron emission tomography in patients with severely impaired LV-function undergoing surgical revascularization

In patients with ischemic cardiomyopathy, coronary artery bypass grafting (CABG) offers an important therapeutic option but is still associated with high perioperative mortality. Although previous studies suggest a benefit from revascularization for patients with defined viability by a non-invasive technique, the role of viability assessment to determine suitability for revascularization in patients with ischemic cardiomyopathy has not yet been defined. This study evaluates the hypothesis that the use of PET imaging in the decision-making process for CABG will improve postoperative patient survival. We reviewed 476 patients with ischemic cardiomyopathy (LV ejection fraction ≤0.35) who were considered candidates for CABG between 1994 and 2004 on the basis of clinical presentation and angiographic data. In a Standard Care Group, 298 patients underwent CABG. In a second PET-assisted management group of 178 patients, 152 patients underwent CABG (PET-CABG) and 26 patients were excluded from CABG because of lack of viability (PET-Alternatives). Primary endpoint was postoperative survival. There were two in hospital deaths in the PET-CABG (1.3%) and 30 (10.1%) in the Standard Care Group (P = 0.018). The survival rate after 1, 5 and 9.3 years was 92.0, 73.3 and 54.2% in the PET-CABG and 88.9, 62.2 and 35.5% in the Standard Care Group, respectively (P = 0.005). Cox-regression analysis revealed a significant influence on long-term survival of patient selection by viability assessment via PET (P = 0.008), of LV-function (P = 0.017), and age >70 (P = 0.016). Preoperative assessment of myocardial viability via PET identifies patients, who will benefit most from CABG.

Mathematical modelling to identify patients who should not undergo left ventricle remodelling surgery

A mathematical model was developed to predict the cardiac output post left ventricle volume reduction surgery (LVVRS) to establish who should not undergo surgery. Two scenarios were evaluated: dilated cardiomyopathy (DCM), and left ventricular wall aneurysm (LVA). In DCM, a left ventricular diastolic volume (LVDV) of 380 ml, ejection fraction (EF) of 15%, and a heart rate of 80, produces a cardiac output of 4.5 l/min. After LVVRS for DCM to reduce the LV volume to 315 ml, the EF is unchanged, but the cardiac output drops by 0.7 l/min. In LV aneurysms, a LVDV of 380 ml, EF of 15%, and a heart rate of 80, produces a cardiac output of 4.5 l/min. After LVVRS for LVA reducing the LV volume to 320 ml, the EF increases to 56%, and the predicted cardiac output doubles. LVVRS is potentially very hazardous in the setting of DCM, confirmed by the international registry report and the Surgical Treatment for Ischemic Heart Failure Trial. However, in the setting of LVA, the surgery can result in marked improvement in cardiac output. The effect on postoperative cardiac output, due to the extent of LV resection can potentially be modelled for preoperatively.

Left ventricular aneurysm using the Dor technique: mid-term results

OBJECTIVE

We have retrospectively analyzed the early and the mid-term results of the operations for modified endoventricular circular patch plasty for left ventricular aneurysm (LVA) repair in our clinic.

PATIENTS AND METHODS

Sixty-seven cases with anterior LVA were included in the study. Mean age of the patients were 64.8 +/- 8.9 (ranged from 51 to 74) years. Fifty-three patients were male and 14 female (M:F = 3.8). Preoperative left ventricular ejection fraction (LVEF) was 30.8% +/- 4.5%, LV end-diastolic diameter (LVEDD) 6.0 +/- 1.9 cm, and end-systolic diameter (LVESD) was 4.6 +/- 0.8 cm in average. Coronary revascularization was performed in 61 patients and mitral ring annuloplasty in five patients.

RESULTS

Thirty-day mortality was 5.9%. The surviving 63 patients were followed up for 4.3 +/- 2.3 years on average (ranged from 0.2 to 8.5 years), adding up to 267.8 patient/years. In the immediate postoperative and long-term follow-up, there was a significant improvement in LVEF, LVESD, LVEDD, and mitral valvular function. Four patients died in the follow-up with only a single patient due to cardiac causes. The five years survival was 87.7% +/- 4.1% and the freedom from cardiac death was 98.2% +/- 1.7%.

CONCLUSION

LVA repair with Dor procedure can be performed with low mortality. With appropriate repair of LVA and coronary revascularization, patients may have benefit both for survival and also for clinical status.

Efficacy of aneurysmectomy in patients with severe left ventricular dysfunction: favorable short-and long-term results in ischemic cardiomyopathy

INTRODUCTION

The purpose of this study was to (1) identify the functional results after aneurysm surgery in patients with ischemic cardiomyopathy and (2) identify predictors of favorable outcomes.

METHODS AND MATERIAL

Patients (n = 169) with angiographic left ventricular ejection fraction of 22 ± 5% underwent aneurysm surgery and were prospectively followed for three years. Prior to surgery, 40% and 60% of the patients were in congestive heart failure NYHA class I/II and III/IV, respectively. Concomitant revascularization was performed on 95% of the patients.

RESULTS

Cumulative in-hospital and 36-month mortalities were 7% and 15%, respectively. These respective rates varied according to preoperative parameters: CHF class I-II, 4% and 13%; CHF class III-IV, 8% and 16%; LVEF,20%, 12% and 26%; LVEF 21-30%, 2% and 6%; gated LVEF exercise/rest .5%, ,1% and 4%; and gated LVEF exercise/rest #5%, 17% and 38%. Higher LVEF ex/rest ratio (p = 0.01), male sex (p = 0.05), and a higher number of grafts (p = 0.01) were predictive of improvement in CHF class at follow-up based on the results of a multivariate analysis. After three years of follow-up, 84% of the patients were in class I/II, LVEF was 45 ± 7%, and gated LVEF ex/rest ratio was 13% higher (p,0.01) compared to the beginning of the study.

CONCLUSIONS

These data suggest that aneurysmectomy among patients with severe LV dysfunction result in short and long-term favorable functional outcome and survival. Selection of appropriate surgical candidates may substantially improve survival rates among these patients.

Cardiac support devices

Heart failure is an increasingly common condition in the United States and is associated with high mortality and burden to health care. It is a chronic condition that is characterized by progressive left ventricular enlargement. While medical therapy can slow the progression of left ventricular remodeling, surgical approaches to treatment have been developed to improve the survival and quality of life of heart failure patients. This article reviews the surgical procedures for left ventricular dysfunction and focuses on cardiac support devices as a new therapy for heart failure patients. The nursing care of patients with cardiac support devices will be presented and a case study will highlight practical points to help guide patient care.

Cellular cardiac regenerative therapy in which patients?

Cell-based myocardial regenerative therapy is undergoing experimental and clinical trials in order to limit the consequences of decreased contractile function and compliance of damaged ventricles owing to ischemic and nonischemic myocardial diseases. A variety of myogenic and angiogenic cell types have been proposed, such as skeletal myoblasts, mononuclear and mesenchymal bone marrow cells, circulating blood-derived progenitors, adipose-derived stromal cells, induced pluripotent stem cells, umbilical cord cells, endometrial mesenchymal stem cells, adult testis pluripotent stem cells and embryonic cells. Current indications for stem cell therapy concern patients who have had a left- or right-ventricular infarction or idiopathic dilated cardiomyopathies. Other indications and potential applications include patients with diabetic cardiomyopathy, Chagas heart disease (American trypanosomiasis), ischemic mitral regurgitation, left ventricular noncompacted myocardium and pediatric cardiomyopathy. Suitable sources of cells for cardiac implant will depend on the types of diseases to be treated. For acute myocardial infarction, a cell that reduces myocardial necrosis and augments vascular blood flow will be desirable. For heart failure, cells that replace or promote myogenesis, reverse apoptopic mechanisms and reactivate dormant cell processes will be useful. It is important to note that stem cells are not an alternative to heart transplantation; selected patients should be in an early stage of heart failure as the goal of this regenerative approach is to avoid or delay organ transplantation. Since the cell niche provides crucial support needed for stem cell maintenance, the most interesting and realistic perspectives include the association of intramyocardial cell transplantation with tissue-engineered scaffolds and multisite cardiac pacing in order to transform a passive regenerative approach into a 'dynamic cellular support', a promising method for the creation of 'bioartificial myocardium'.

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.

Hotline sessions presented at the American College of Cardiology Congress 2009

The article summarizes the results of clinical trials in the field of cardiovascular medicine, which were presented during the Hotline Sessions at the annual meeting of the American College of Cardiology in Orlando, USA, from 28th March to 31st March 2009. The data were presented by leading experts in the field with relevant positions within the trials. Unpublished reports should be considered as preliminary data as the analysis may change in the final publications. The summaries presented in the manuscript were generated from the oral presentations and provide the readers with the comprehensive information on the results of the latest clinical trials in cardiovascular medicine.

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.

Cardiomyopathy: an overview

Cardiomyopathy is an anatomic and pathologic diagnosis associated with muscle or electrical dysfunction of the heart. Cardiomyopathies represent a heterogeneous group of diseases that often lead to progressive heart failure with significant morbidity and mortality. Cardiomyopathies may be primary (i.e., genetic, mixed, or acquired) or secondary (e.g., infiltrative, toxic, inflammatory). Major types include dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Although cardiomyopathy is asymptomatic in the early stages, symptoms are the same as those characteristically seen in any type of heart failure and may include shortness of breath, fatigue, cough, orthopnea, paroxysmal nocturnal dyspnea, and edema. Diagnostic studies include B-type natriuretic peptide levels, baseline serum chemistries, electrocardiography, and echocardiography. Treatment is targeted at relieving the symptoms of heart failure and reducing rates of heart failure-related hospitalization and mortality. Treatment options include pharmacotherapy, implantable cardioverter-defibrillators, cardiac resynchronization therapy, and heart transplantation. Recommended lifestyle changes include restricting alcohol consumption, losing weight, exercising, quitting smoking, and eating a low-sodium diet.