Mark F. Berry

Apelin Has In Vivo Inotropic Effects on Normal and Failing Hearts

Background—Apelin has been shown ex vivo to be a potent cardiac inotrope. This study was undertaken to evaluate the in vivo effects of apelin on cardiac function in native and ischemic cardiomyopathic rat hearts using a novel combination of a perivascular flow probe and a conductance catheter. Methods and Results—Native rats (n =32) and rats in heart failure 6 weeks after left anterior descending coronary artery ligation (n =22) underwent median sternotomy with placement of a perivascular flow probe around the ascending aorta and a pressure volume conductance catheter into the left ventricle. Compared with sham-operated rats, the ligated rats had significantly decreased baseline Pmax and max dP/dt. Continuous infusion of apelin at a rate of 0.01 &mgr;g/min for 20 minutes significantly increased Pmax and max dP/dt compared with infusion of vehicle alone in both native and failing hearts. Apelin infusion increased cardiac contractility, indicated by a significant increase in stroke volume (SV) without a change in left ventricular end diastolic volume (102±16% change from initial SV versus 26±20% for native animals, and 110±30% versus 26±11% for ligated animals), as well as an increase in preload recruitable stroke work (180±24 mm Hg versus 107±9 mm Hg for native animals). Conclusions—The present study is the first to show that apelin has positive inotropic effects in vivo in both normal rat hearts and rat hearts in failure after myocardial infarction. Apelin may have use as an acute inotropic agent in patients with ischemic heart failure.

Thoracoscopic lobectomy has increasing benefit in patients with poor pulmonary function: a Society of Thoracic Surgeons Database analysis.

Objective:Using a national database, we asked whether video-assisted thoracoscopic surgery (VATS) lobectomy is beneficial in high-risk pulmonary patients. Background:Single-institution series demonstrated benefit of VATS lobectomy over lobectomy via thoracotomy in poor pulmonary function patients [FEV1 (forced expiratory volume in 1 second) or DLCO (diffusion capacity of the lung to carbon monoxide) <60% predicted]. Methods:The STS General Thoracic Database was queried for patients having undergone lobectomy by either thoracotomy or VATS between 2000 and 2010. Postoperative pulmonary complications included those defined by the STS database. Results:In the STS database, 12,970 patients underwent lobectomy (thoracotomy, n = 8439; VATS, n = 4531) and met inclusion criteria. The overall rate of pulmonary complications was 21.7% (1832/8439) and 17.8% (806/4531) in patients undergoing lobectomy with thoracotomy and VATS, respectively (P < 0.0001). In a multivariable model of pulmonary complications, thoracotomy approach (OR = 1.25, P < 0.001), decreasing FEV1% predicted (OR = 1.01 per unit, P < 0.001) and DLCO% predicted (OR = 1.01 per unit, P < 0.001), and increasing age (1.02 per year, P < 0.001) independently predicted pulmonary complications. When examining pulmonary complications in patients with FEV1 less than 60% predicted, thoracotomy patients have markedly increased pulmonary complications when compared with VATS patients (P = 0.023). No significant difference is noted with FEV1 more than 60% predicted. Conclusions:Poor pulmonary function predicts respiratory complications regardless of approach. Respiratory complications increase at a significantly greater rate in lobectomy patients with poor pulmonary function after thoracotomy compared with VATS. Planned surgical approach should be considered while determining whether a high-risk patient is an appropriate resection candidate.

Gene Transfer of Hepatocyte Growth Factor Attenuates Postinfarction Heart Failure

Background—Despite advances in surgical and percutaneous coronary revascularization, ongoing ischemia that is not amenable to standard revascularization techniques is a major cause of morbidity and mortality. Hepatocyte Growth Factor (HGF) has potent angiogenic and anti-apoptotic activities, and this study evaluated the functional and biochemical effects of HGF gene transfer in a rat model of postinfarction heart failure. Methods and Results—Lewis rats underwent ligation of the left anterior descending coronary artery with direct intramyocardial injection of replication-deficient recombinant adenovirus encoding HGF (n=10) or empty null virus as control (n=9), and animals were analyzed after six weeks. Pressure-volume conductance catheter measurements demonstrated significantly preserved contractile function in the HGF group compared with Null control animals as measured by maximum developed LV pressure (79±5 versus 56±4 mm Hg, P <0.001) and maximum dP/dt (2890±326 versus 1622±159 mm Hg/sec, P <0.01). Significant preservation of LV geometry was associated with HGF treatment (LV Diameter HGF 13.1±0.54 versus Null 14.4±0.15 mm P <0.01; LV wall thickness 1.73±0.10 versus 1.28±0.07 mm P <0.01). Angiogenesis was significantly enhanced in HGF treated animals as measured by both Von Willebrand’s Factor immunohistochemical staining and a microsphere assay. TUNEL analysis revealed a significant reduction in apoptosis in the HGF group (3.42±0.83% versus 8.36±1.16%, P <0.01), which correlated with increased Bcl-2 and Bcl-xL expression in the HGF animals. Conclusions—Hepatocyte Growth Factor gene transfer following a large myocardial infarction results in significantly preserved myocardial function and geometry, and is associated with significant angiogenesis and a reduction in apoptosis. This therapy may be useful as an adjunct or alternative to standard revascularization techniques in patients with ischemic heart failure.

Ischemic heart failure enhances endogenous myocardial apelin and APJ receptor expression

Apelin interacts with the APJ receptor to enhance inotropy. In heart failure, apelin-APJ coupling may provide a means of enhancing myocardial function. The alterations in apelin and APJ receptor concentrations with ischemic cardiomyopathy are poorly understood. We investigated the compensatory changes in endogenous apelin and APJ levels in the setting of ischemic cardiomyopathy.Male, Lewis rats underwent LAD ligation and progressed into heart failure over 6 weeks. Corresponding animals underwent sham thoracotomy as control. Six weeks after initial surgery, the animals underwent hemodynamic functional analysis in the presence of exogenous apelin-13 infusion and the hearts were explanted for western blot and enzyme immunoassay analysis.Western blot analysis of myocardial APJ concentration demonstrated increased APJ receptor protein levels with heart failure (1890750±133500 vs. 901600±143120 intensity units, n=8, p=0.00001). Total apelin protein levels increased with ischemic heart failure as demonstrated by enzyme immunoassay (12.0±4.6 vs. 1.0±1.2 ng/ml, n=5, p=0.006) and western blot (1579400±477733 vs. 943000±157600 intensity units, n=10, p=0.008). Infusion of apelin-13 significantly enhanced myocardial function in sham and failing hearts. We conclude that total myocardial apelin and APJ receptor levels increase in compensation for ischemic cardiomyopathy.

Risk Factors for Morbidity After Lobectomy for Lung Cancer in Elderly Patients

BACKGROUND Studies evaluating risk factors for complications after lobectomy in elderly patients have not adequately analyzed the effect of using minimally invasive approaches. METHODS A model for morbidity including published preoperative risk factors and surgical approach was developed by multivariable logistic regression. All patients aged 70 years or older who underwent lobectomy for primary lung cancer without chest wall resection or airway procedure between December 1999 and October 2007 at a single institution were reviewed. Preoperative, histopathologic, perioperative, and outcome variables were assessed using standard descriptive statistics. Morbidity was measured as a patient having any perioperative complication. The impact of bias in the selection of surgical approach was assessed using propensity scoring. RESULTS During the study period, 338 patients older than 70 years (mean age, 75.7 +/- 0.2) underwent lobectomy (219 thoracoscopy, 119 thoracotomy). Operative mortality was 3.8% (13 patients) and morbidity was 47% (159 patients). Patients with at least one complication had increased length of stay (8.3 +/- 0.6 versus 3.8 +/- 0.1 days; p < 0.0001) and mortality (6.9% [11 of 159] versus 1.1% [2 of 179]; p = 0.008). Significant predictors of morbidity by multivariable analysis included age (odds ratio, 1.09 per year; p = 0.01) and thoracotomy as surgical approach (odds ratio, 2.21; p = 0.004). Thoracotomy remained a significant predictor of morbidity when the propensity to undergo thoracoscopy was considered (odds ratio, 4.9; p= 0.002). CONCLUSIONS Patients older than 70 years of age can undergo lobectomy for lung cancer with low morbidity and mortality. Advanced age and the use of a thoracotomy increased the risk of complications in this patient population.

Pulmonary Function Tests Do Not Predict Pulmonary Complications After Thoracoscopic Lobectomy

BACKGROUND Pulmonary function tests predict respiratory complications and mortality after lung resection through thoracotomy. We sought to determine the impact of pulmonary function tests upon complications after thoracoscopic lobectomy. METHODS A model for morbidity, including published preoperative risk factors and surgical approach, was developed by multivariable logistic regression. All patients who underwent lobectomy for primary lung cancer between December 1999 and October 2007 with preoperative forced expiratory volume in 1 second (FEV1) or diffusion capacity to carbon monoxide (Dlco) 60% or less predicted were reviewed. Preoperative, histopathologic, perioperative, and outcome variables were assessed using standard descriptive statistics. Pulmonary complications were defined as atelectasis requiring bronchoscopy, pneumonia, reintubation, and tracheostomy. RESULTS During the study period, 340 patients (median age 67) with Dlco or FEV1 60% or less (mean % predicted FEV1, 55+/-1; mean % predicted Dlco, 61+/-1) underwent lobectomy (173 thoracoscopy, 167 thoracotomy). Operative mortality was 5% (17 patients) and overall morbidity was 48% (164 patients). At least one pulmonary complication occurred in 57 patients (17%). Significant predictors of pulmonary complications by multivariable analysis for all patients included Dlco (odds ratio 1.03, p=0.003), FEV1 (odds ratio 1.04, p=0.003), and thoracotomy as surgical approach (odds ratio 3.46, p=0.0007). When patients were analyzed according to operative approach, Dlco and FEV1 remained significant predictors of pulmonary morbidity for patients undergoing thoracotomy but not thoracoscopy. CONCLUSIONS In patients with impaired pulmonary function, preoperative pulmonary function tests are predictors of pulmonary complications when lobectomy for lung cancer is performed through thoracotomy but not through thoracoscopy.

Induction Chemoradiation Is Not Superior to Induction Chemotherapy Alone in Stage IIIA Lung Cancer

BACKGROUND The optimal treatment strategy for patients with operable stage IIIA (N2) non-small cell lung cancer is uncertain. We performed a systematic review and meta-analysis to test the hypothesis that the addition of radiotherapy to induction chemotherapy prior to surgical resection does not improve survival compared with induction chemotherapy alone. METHODS A comprehensive search of PubMed for relevant studies comparing patients with stage IIIA (N2) non-small cell lung cancer undergoing resection after treatment with induction chemotherapy alone or induction chemoradiotherapy was conducted using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standards. Hazard ratios were extracted from these studies to give pooled estimates of the effect of induction therapy on overall survival. RESULTS There were 7 studies that met criteria for analysis, including 1 randomized control trial, 1 phase II study, 3 retrospective reviews, and 2 published abstracts of randomized controlled trials. None of the studies demonstrated a survival benefit to adding induction radiation to induction chemotherapy versus induction chemotherapy alone. The meta-analysis performed on randomized studies (n=156 patients) demonstrated no benefit in survival from adding radiation (hazard ratio 0.93, 95% confidence interval 0.54 to 1.62, p=0.81), nor did the meta-analysis performed on retrospective studies (n=183 patients, hazard ratio 0.77, 95% confidence interval 0.50 to 1.19, p=0.24). CONCLUSIONS Published evidence is sparse but does not support the use of radiation therapy in induction regimens for stage IIIA (N2). Given the potential disadvantages of adding radiation preoperatively, clinicians should consider using this treatment strategy only in the context of a clinical trial to allow better assessment of its effectiveness.

Esophageal cancer: staging system and guidelines for staging and treatment

Survival of esophageal cancer is improving but remains poor. Esophageal cancer stage is based on depth of tumor invasion, involvement of regional lymph nodes, and the presence or absence of metastatic disease. Appropriate work-up is critical to identify accurate pre-treatment staging so that both under-treatment and unnecessary treatment is avoided. Treatment strategy should follow guideline recommendations, and generally should be developed after multidisciplinary evaluation.

Lymphovascular Invasion in Non–Small-Cell Lung Cancer: Implications for Staging and Adjuvant Therapy

Background: Lymphovascular space invasion (LVI) is an established negative prognostic factor and an indication for postoperative radiation therapy in many malignancies. The purpose of this study was to evaluate LVI in patients with early-stage non–small-cell lung cancer, undergoing surgical resection. Methods: All patients who underwent initial surgery for pT1-3N0-2 non–small-cell lung cancer at Duke University Medical Center from 1995 to 2008 were identified. A multivariate ordinal regression was used to assess the relationship between LVI and pathologic hilar and/or mediastinal lymph node (LN) involvement. A multivariate Cox regression analysis was used to evaluate the relationship of LVI and other clinical and pathologic factors on local failure (LF), freedom from distant metastasis (FFDM), and overall survival (OS). Kaplan-Meier methods were used to generate estimates of LF, FFDM, and OS in patients with and without LVI. Results: One thousand five hundred and fifty-nine patients were identified. LVI was independently associated with the presence of regional LN involvement (p < 0.001) along with lobar (versus sublobar) resections (p < 0.001), and an open thoracotomy (versus video-assisted thoracoscopic surgery). LVI was not independently associated with LF on multivariate analysis (hazard ratio [HR] = 1.23, p = 0.25), but was associated with a lower FFDM (HR 1.52, p = 0.005) and OS (HR 1.26, p = 0.015). In addition, multivariate analysis showed that LVI was strongly associated with increased risk of developing distant metastases (HR = 1.75, p = 0.006) and death (HR = 1.53, p = 0.003) in adenocarcinomas but not in squamous carcinomas. Conclusions: LVI is associated with an increased risk of harboring regional LN involvement. LVI is also an adverse prognostic factor for the development of distant metastases and long-term survival.

A model for morbidity after lung resection in octogenarians

OBJECTIVE Age is an important risk factor for morbidity after lung resection. This study was performed to identify specific risk factors for complications after lung resection in octogenarians. METHODS A prospective database containing patients aged 80 years or older, who underwent lung resection at a single institution between January 2000 and June 2009, was reviewed. Preoperative, histopathologic, perioperative, and outcome variables were assessed. Morbidity was measured as a patient having any perioperative event as defined by the Society of Thoracic Surgeons General Thoracic Surgery Database. A multivariable risk model for morbidity was developed using a panel of established preoperative and operative variables. Survival was calculated using the Kaplan-Meier method. RESULTS During the study period, 193 patients aged 80 years or older (median age 82 years) underwent lung resection: wedge resection in 77, segmentectomy in 13, lobectomy in 96, bilobectomy in four, and pneumonectomy in three. Resection was accomplished via thoracoscopy in 149 patients (77%). Operative mortality was 3.6% (seven patients) and morbidity was 46% (89 patients). A total of 181 (94%) patients were discharged directly home. Postoperative events included atrial arrhythmia in 38 patients (20%), prolonged air leak in 24 patients (12%), postoperative transfusion in 22 patients (11%), delirium in 16 patients (8%), need for bronchoscopy in 14 patients (7%), and pneumonia in 10 patients (5%). Significant predictors of morbidity by multivariable analysis included resection greater than wedge (odds ratio 2.98, p=0.006), thoracotomy as operative approach (odds ratio 2.6, p=0.03), and % predicted forced expiratory volume in 1s (odds ratio 1.28 for each 10% decrement, p=0.01). CONCLUSIONS Octogenarians can undergo lung resection with low mortality. Extent of resection, use of a thoracotomy, and impaired lung function increase the risk of complications. Careful evaluation is necessary to select the most appropriate approach in octogenarians being considered for lung resection.