Faculty Bibliography

BACKGROUND AND AIM OF THE STUDY: Patients with heart valve surgery may have a periprocedural mortality extending up to one year after surgery. The study aim was to determine independent predictors for in-hospital and long-term mortality after heart valve surgery. METHODS: A total of 1,376 consecutive patients who underwent isolated or combined heart valve surgery at a single institution was studied. Multivariate logistic regression analysis was used to determine independent predictors for in-hospital mortality. Long-term survival data (mean follow up 5.6 years) were obtained from the National Death Index. Multivariate Cox regression analysis was used to determine independent predictors for long-term mortality. All available preoperative, intraoperative and postoperative risk factors were included in these analyses. RESULTS: The mean EuroSCORE was 6.2 +/- 3.7. There were 86 (6.3%) in-hospital and 550 (40.0%) late deaths. Eleven independent predictors were determined for in-hospital mortality, and 13 for long-term mortality. There were six common independent predictors (preoperative dialysis, total bypass time, intraoperative stroke, postoperative sepsis and/or endocarditis, renal and respiratory failure). Unique independent predictors for in-hospital mortality included intra-aortic balloon pump, preoperative endocarditis, intravenous use of nitroglycerine, bleeding requiring reoperation and gastrointestinal complications. The model for in-hospital mortality showed acceptable calibration (Lemeshow-Hosmer, p = 0.629) and excellent discriminatory ability (C statistic 0.88). Unique independent predictors for long-term mortality included age, ejection fraction, stroke prior to surgery, hemodynamic instability, chronic obstructive pulmonary disease and deep sternal wound infection. CONCLUSION: Independent predictors were determined for early and long-term mortality after heart valve surgery. The prevention of postoperative complications may be a key element for increased early and long-term survival in these patients.

Stroke after coronary artery bypass grafting (CABG) is an infrequent, yet devastating complication with increased morbidity and mortality. We sought to determine risk factors for early (intraoperatively to 24 hours) and delayed (>24 hours to discharge) stroke and to identify their impact on long-term mortality after CABG. We studied 4,140 consecutive patients who underwent isolated CABG from 1992 to 2003. Long-term survival data (mean follow-up 7.4 years) were obtained from the National Death Index. Independent predictors for stroke and in-hospital mortality were determined by multivariate logistic regression analysis including all available preoperative, intraoperative, and postoperative risk factors. Independent predictors for long-term mortality were determined by multivariate Cox regression analysis. One hundred two patients (2.5%) developed early stroke and 36 patients (0.9%) delayed stroke. Independent predictors for early stroke were age, recent myocardial infarction, smoking, femoral vascular disease, body mass index, reoperation for bleeding, postoperative sepsis and/or endocarditis, and respiratory failure, whereas those for delayed stroke were female gender, white race, preoperative renal failure, respiratory failure, and postoperative renal failure. Early stroke was an independent predictor for in-hospital (odds ratio 3.49, 95% confidence interval [CI] 1.56 to 7.80, p = 0.002) and long-term (hazard ratio 1.70, 95% CI 1.30 to 2.21, p <0.001) mortalities. Delayed stroke was not an independent predictor for in-hospital (odds ratio 0.90, 95% CI 0.23 to 3.51, p = 0.878) or long-term (hazard ratio 0.66, 95% CI 0.38 to 1.17, p = 0.156) mortality. In conclusion, risk factors for early in-hospital stroke differ from those of delayed in-hospital stroke after CABG. Early stroke is an independent predictor for in-hospital and long-term mortalities, suggesting the need for a more frequent follow-up and appropriate pharmacologic therapy after discharge.

Hypertrophic cardiomyopathy is a heterogeneous disease with both medical and surgical treatment options. Patients who are symptomatic with a left ventricular outflow tract (LVOT) gradient of >50 mm Hg are referred for septal myectomy. A review of both early and recent literature of outcomes of surgical therapy was performed. Specialized centers referred large numbers of patients for septal myectomy were the focus. Overall improvement in symptoms, morbidity, mortality, and long-term survival were reviewed. Over the past 40 years, surgical therapy has shown consistent improvement in symptoms and reduction of LVOT gradient for patients with hypertrophic cardiomyopathy. Furthermore, there has been a significant decrease in both morbidity and mortality for septal myectomy with improved techniques in the field of cardiac surgery and better understanding of the pathophysiology of the disease process. Surgical resection of the septum for hypertrophic cardiomyopathy is a safe, reproducible, and effective procedure for symptomatic patients with a significant LVOT obstruction.

OBJECTIVE: The surgical management of left ventricular outflow tract (LVOT) obstruction secondary to hypertrophic cardiomyopathy (HCM) has classically consisted of a septal myectomy. To address inconsistent results the extended myectomy or resection (R) and papillary muscle release (R) have been described. Our group introduced a novel addition to the surgical management consisting of an anterior mitral leaflet plication (P). We call the procedure resection - plication- release for repair of complex HCM pathology - the RPR operation. We investigated the mid-term results of all our patients undergoing surgical management for simple and complex HCM pathology. METHODS: Forty-two patients have undergone surgery for HCM at our hospital center since we began to look critically at the pathophysiology. Patients received either an extended myectomy alone, a myectomy plus either papillary muscle release or mitral leaflet plication, or the total RPR procedure. Pre and post-operative transesophageal echocardiograms were obtained in all patients to assess LVOT gradient, adequacy of resection and degree of mitral insufficiency. Subsequently, all patients had a trans-thoracic echocardiogram at a mean follow-up period of 3.4 +/- 3.1 years (range, 0.5 to 7). RESULTS: Twenty-one patients underwent the full RPR procedure; thirteen received portions of the procedure and only seven underwent myectomy alone (including three with concomitant mitral valve replacement (MVR) for insufficiency unrelated to their obstructive pathology). One patient had an isolated MVR as primary therapy for HCM management. The average age was 56 +/-14 years. The preoperative LVOT obstruction gradient was 137 +/- 45 mm Hg and reduced to 10 +/- 17 mm Hg post-operatively. All patients had mitral insufficiency pre-operatively, grade 3.1 on average (scale 0-4), and reduced post-operatively to trivial, grade 0.2. During the follow-up period, LVOT gradient remained low at 6 +/- 14 mm Hg, and mitral insufficiency remained trivial, grade 0.4 (All p values <0.0001). There were no hospital deaths and overall, no need for reoperations. CONCLUSIONS: Hypertrophic cardiomyopathy patients often present with wide anatomic variation. When these variations are understood, the operative approach should be directed to correct or ameliorate those specific aspects, termed simple or complex pathophysiology. Durable long-term results can be achieved in all patients when the mitral valve pathology is appreciated and appropriately repaired, along with a properly located and adequately sized septal myectomy.

The purpose of the present study was to determine independent predictors for long-term mortality after cardiac surgery. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was developed to score in-hospital mortality and recent studies have shown its ability to predict long-term mortality as well. We compared forecasts based on EuroSCORE with other models based on independent predictors. Medical records of patients with cardiac surgery who were discharged alive (n = 4852) were retrospectively reviewed. Their operative surgical risks were calculated according to EuroSCORE. Patients were randomly divided into two groups: training dataset (n = 3233) and validation dataset (n = 1619). Long-term survival data (mean follow-up 5.1 years) were obtained from the National Death Index. We compared four models: standard EuroSCORE (M1); logistic EuroSCORE (M2); M2 and other preoperative, intra-operative and post-operative selected variables (M3); and selected variables only (M4). M3 and M4 were determined with multivariable Cox regression analysis using the training dataset. The estimated five-year survival rates of the quartiles in compared models in the validation dataset were: 94.5%, 87.8%, 77.1%, 64.9% for M1; 95.1%, 88.0%, 80.5%, 64.4% for M2; 93.4%, 89.4%, 80.8%, 64.1% for M3; and 95.8%, 90.9%, 81.0%, 59.9% for M4. In the four models, the odds of death in the highest-risk quartile was 8.4-, 8.5-, 9.4- and 15.6-fold higher, respectively, than the odds of death in the lowest-risk quartile (P < 0.0001 for all). EuroSCORE is a good predictor of long-term mortality after cardiac surgery. We developed and validated a model using selected preoperative, intra-operative and post-operative variables that has better discriminatory ability.

BACKGROUND: The purpose of the present study was to determine whether long-term survival in diabetic patients increased after bilateral internal thoracic artery (BITA) coronary bypass compared with matched patients with single internal thoracic artery (SITA) coronary bypass. METHODS: The propensity for BITA was determined using logistic regression analysis and each BITA patient was matched with one SITA patient. Between January 1992 and March 2002, 980 matched diabetic patients (490 BITA versus 490 SITA) underwent coronary artery bypass surgery. Long-term survival data were obtained from the National Death Index (mean follow-up, 4.7 +/- 3.0 years). Groups were compared by Cox proportional hazard models and Kaplan-Meier survival plots. RESULTS: Multivariate Cox regression analysis determined that BITA grafting had no significant effect on long-term survival (hazard ratio 0.89, 95% confidence interval: 0.69 to 1.14, p = 0.343). There were no differences in 30-day mortality (3.9% for BITA versus 3.7%, p = 0.999) and major postoperative complications except for length of stay (11.4 days for BITA versus 12.7 days, p < 0.001). Five-year survival rate was 79.9% in the BITA group and 75.7% in the SITA group (p = 0.252). There was no difference in 5-year survival rate between matched patients younger than 60 or from 70 to 79 years old. However, BITA patients aged 60 to 69 years had better 5-year survival rates (84.1% versus 71.0%, p = 0.0196), whereas the opposite was observed in patients aged more than 79 years (5-year survival for BITA 43.1% versus 70.0%, p = 0.016). CONCLUSIONS: Bilateral internal thoracic artery grafting had no significant effect on long-term survival for diabetic patients, but it may increase long-term survival in patients aged 60 to 69 years, whereas SITA grafting may be beneficial for patients more than 79 years old.

OBJECTIVE: The long-term mortality of coronary artery bypass grafting in women in not certain. The purpose of this study was to determine and compare risk factors for long-term mortality in women and men undergoing coronary artery bypass grafting. METHODS: Between 1992 and 2002, 3760 consecutive patients (2598 men and 1162 women) underwent isolated coronary artery bypass grafting. Long-term survival data were obtained from the National Death Index (mean follow-up, 5.1 +/- 3.2 years). Multivariable Cox regression analysis was performed, including 64 preoperative, intraoperative, and postoperative factors separately in women and men. RESULTS: There were no differences in in-hospital mortality (2.7% in men vs 2.9% in women, P = .639) and 5-year survival (82.0% +/- 0.8% in men vs 81.1% +/- 1.3% in women, P = .293). After adjustment for all independent predictors of long-term mortality, female sex was an independent predictor of improved 5-year survival (hazard ratio, 0.82; 95% confidence interval, 0.71-0.96; P = .014). Twenty-one independent predictors for long-term mortality were determined in men, whereas only 12 were determined in women. There were 9 common risk factors (age, ejection fraction, diabetes mellitus, > or =2 arterial grafts, postoperative myocardial infarction, deep sternal wound infection, sepsis and/or endocarditis, gastrointestinal complications, and respiratory failure); however, their weights were different between women and men. Malignant ventricular arrhythmias, calcified aorta, and preoperative renal failure were independent predictors only in women. Emergency operation, previous cardiac operation, peripheral vascular disease, left ventricular hypertrophy, current and past congestive heart failure, chronic obstructive pulmonary disease, body mass index of greater than 29, preoperative dialysis, thrombolysis within 7 days before coronary artery bypass grafting, intraoperative stroke, and postoperative renal failure were independent predictors only in men. CONCLUSIONS: Despite equality between sexes in early outcome and superiority of female sex in long-term survival, there were 3 independent predictors for long-term mortality after coronary artery bypass grafting unique for women compared with 12 for men. Clinical decision making and follow-up should not be influenced by stereotypes but by specific findings.

BACKGROUND: : Robotically assisted left ventricular (LV) lead placement is an effective minimally invasive rescue procedure for cardiac resynchronization in the setting of failed coronary sinus lead insertion. The long-term response rate and durability of this technique has not been reported. The authors evaluated the midterm outcome of biventricular pacing performed with robotically placed LV leads. METHODS: : Forty-two patients underwent implantation of LV epicardial leads using robotic assistance and the posterior approach. Half of the patients had prior cardiac surgery. All leads were placed in an optimal site along the posterolateral surface of the LV. The patients were prospectively followed up for clinical response, LV reverse remodeling, and LV lead stability over a mean period of 16.7 +/- 9.5 months (range, 3-34 months). A multivariate Cox proportional hazards model was used to determine predictors of response. RESULTS: : All patients had successful LV lead placement with no postoperative mortality. Statistically significant improvements in left ventricular ejection fraction, NYHA heart failure class, systolic left ventricular internal dimension index, and diastolic left ventricular internal dimension index. The 3-month clinical response rate was 81% and dropped to 71% at average maximal follow-up. Multivariate analysis of 9 variables revealed only LVEF greater than 15% and absence of pulmonary hypertension to be predictors of response. No difference in operative time, response rate, or LV lead stability was detected when primary versus reoperative cases were compared. CONCLUSIONS: : Robotic LV lead placement is a reliable technique for optimal lead placement with durable long-term results.

BACKGROUND: To evaluate the performance of EuroSCORE in the prediction of in-hospital postoperative length of stay and specific major postoperative complications after coronary artery bypass grafting (CABG). METHODS: Data on 3760 consecutive patients with CABG were prospectively collected. The EuroSCORE model (standard and logistic) was used to predict in-hospital mortality, prolonged length of stay (>12 days) and major postoperative complications (stroke, myocardial infarction, sternal infection, bleeding, sepsis and/or endocarditis, gastrointestinal complications, renal and respiratory failure). A C statistic (receiver operating characteristic curve) was used to test the discrimination of the EuroSCORE. The calibration of the model was assessed by the Hosmer-Lemeshow goodness-of-fit statistic. RESULTS: In-hospital mortality was 2.7%, and 13.7% of patients had one or more major complications. EuroSCORE showed very good discriminatory ability in predicting renal failure (C statistic: 0.80) and good discriminatory ability in predicting in-hospital mortality (C statistic: 0.75), sepsis and/or endocarditis (C statistic: 0.72) and prolonged length of stay (C statistic: 0.71). There were no differences in terms of the discriminatory ability between standard and logistic EuroSCORE. Standard EuroSCORE showed good calibration (Hosmer-Lemeshow: P>0.05) in predicting these outcomes except for postoperative length of stay, while logistic EuroSCORE showed good calibration only in predicting renal failure. CONCLUSIONS: EuroSCORE can be used to predict not only in-hospital mortality, for which it was originally designed, but also prolonged length of stay and specific postoperative complications such as renal failure and sepsis and/or endocarditis after CABG. These outcomes can be predicted accurately using the standard EuroSCORE which is very simple and easy in its calculation.

We sought to study our mid-term outcomes and our patient's perceptions of robotically-assisted coronary artery bypass (RACAB). The daVinci robotic system was utilized to harvest and prepare the internal thoracic artery (ITA) as well as to open the pericardium and identify the target vessels. Anastomoses were performed by hand on the beating heart through limited incisions using an endoscopic stabilizing device. A follow-up telephone interview was conducted with patients at 3 to 6 months. Between 4/12/02 and 11/1/04, 37 patients underwent RACAB (1.2 distal anastomoses/patient). Median length of stay was 3 days (2-14 days) and 82% of patients reported full return to baseline activity within 10 days of surgery. There were two early LITA complications and one late anastomotic stenosis all of which occurred within the first two cases of each surgeon's experience. The majority of patients surveyed (95%) knew that robotics were involved in their surgery and most patients (95%) would recommend RACAB (95%). RACAB is an effective minimally invasive revascularization technique with excellent recovery times and high patient satisfaction. The early complication rate emphasizes the steep learning curve for this procedure as well as the need for intensive pre-procedure training.