Faculty Bibliography

BACKGROUND: Infective endocarditis is associated with a high rate of long-term mortality. Patients with a history of intravenous drug use (IVDU) are at increased risk for infective endocarditis. However, few studies have reported results of surgical treatment on this population. We present 19.5 years of experience with surgically treated patients with infective endocarditis. METHODS: A retrospective study of all cardiac surgeries with a diagnosis of infective endocarditis at a single institution from 1986 to 2005 was performed. Logistic stepwise regression with an end point of operative mortality was done. Variables were age, gender, race, history of drug use, previous valve surgery, and previous valve replacement. Perioperative and outcome variables were compared between IVDU and non-IVDU populations. RESULTS: The IVDU population required surgery at a younger age (39 +/- 9 years versus 54 +/- 15 years; p < 0.001). Overall operative mortality was 12% (41/346). The perioperative complication rate was similar for both groups. When adjusted for age, the two groups had similar long-term survival (p = 0.78). Kaplan-Meier estimator showed that survival at 10 and 15 years was 66% and 54% for IVDU and 56% and 42% for non-IVDU (number at risk, 19, 11, and 61, 28, respectively; p = 0.137). Reoperation for recurrent infective endocarditis was necessary in 9 (17%) of 52 of the IVDU group versus 14 (5%) of 270 of the non-IVDU group (p = 0.03). CONCLUSIONS: Patients with a history of IVDU required reoperation for recurrent infective endocarditis at a significantly higher rate than the non-IVDU patients. Long-term survival was similar between the younger IVDU population and the older non-IVDU population. Anticipated life span is one of many factors when considering prosthetic valve choice in this population.

OBJECTIVE: Patients with severe left ventricular (LV) dysfunction have a poor long term survival despite complete surgical revascularization. Recent data suggests that the use of Implantable Cardioverter-Defibrillator (ICD) improves survival in patients with severe LV dysfunction. We compared the survival impact of ICD implantation in patients with severe LV dysfunction who underwent CABG. METHODS: Between January 1996 and August 2004, 305 patients with LV ejection fraction (EF) < or = 25% had CABG surgery at our institution. Demographics of patients who had received an ICD (ICD+) in the post -operative period was compared to those without ICD (ICD-). Survival was evaluated by the Kaplan-Meier method. RESULTS: Of the entire group, 35 (11.5%) patients received an ICD with a median of 2 (+/-2) years after CABG. Indication for ICD implantation was clinical evidence of non sustained ventricular tachycardia (NSVT). There were no differences between the 2 groups with respect to age, gender, NYHA classification, number of bypasses, or other co-morbidities. Survival at 1, 3 and 5 years was 88%, 79%, and 67% for the ICD- group compared to 94%, 89% and 83% for the ICD+ group, respectively (figure, p < 0.05). CONCLUSION: Implantation of ICD after CABG confers improved short and long term survival benefit to patients with severe LV dysfunction. Prophylactic ICD implantation in the setting of severe LV dysfunction and CABG surgery should be considered.

OBJECTIVES: Since its introduction in 1987, the Cox-maze procedure has been the gold standard for the surgical treatment of atrial fibrillation. At our institution, this procedure has evolved from the cut-and-sew technique (Cox-maze III procedure) to one using bipolar radiofrequency energy and cryoablation as ablative sources to replace most incisions (Cox-maze IV procedure). This study compared surgical outcomes of patients undergoing the Cox-maze III procedure versus those of patients undergoing the Cox-maze IV procedure by using propensity analysis. METHODS: From April 1992 through July 2005, 242 patients underwent the Cox-maze procedure for atrial fibrillation. Of these, 154 patients had the Cox-maze III procedure, and 88 had the Cox-maze IV procedure. Logistic regression analysis was used to identify covariates among 7 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 58 patients each. Operative outcomes were analyzed for differences. Late follow-up was available for 112 (97%) patients. Freedom from atrial fibrillation recurrence and survival was calculated at 1 year by using Kaplan-Meier analysis. RESULTS: The Cox-maze III procedure had significantly longer crossclamp times. There was no significant difference in intensive care unit and hospital stay, 30-day mortality, permanent pacemaker placement, early atrial tachyarrhythmias, late stroke, and survival. Freedom from atrial fibrillation recurrence was greater than 90% in both groups at 1 year. CONCLUSIONS: The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.

BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is a potentially preventable and often troublesome gastrointestinal complication after cardiac surgery. METHODS: A retrospective study was performed of 8,405 cardiac surgery patients at two institutions between January 1997 and August 2004. Preoperative cardiac risk factors, perioperative factors including blood product transfusion, antibiotic utilization, and postoperative morbidity and mortality were recorded. Univariate and multivariate analyses were performed comparing C. difficile patients with a control group matched by date of surgery and institution. RESULTS: Sixty-six of the 8,405 patients identified with toxin-positive CDAD produced an overall incidence of 0.79% (0.70% at institution A and 1.09% at institution B), with a peak overall incidence of 5.45% in June 2003. Independent prognostic factors for CDAD by multivariate analysis included advancing age (odds ratio [OR] 1.028, 95% confidence interval [CI]: 1.001 to 1.056; p = 0.034), female sex (OR 2.026, 95% CI: 1.102 to 3.722; p = 0.022), blood product transfusion (OR 3.277, 95% CI: 1.292 to 8.311; p = 0.006), and increasing cumulative days of antibiotic administration (OR 1.046, 95% CI: 1.014 to 1.080; p = 0.004). There were no differences in the proportion of fluoroquinolones, cephalosporins, or penicillin derivatives administered between groups. The diagnosis of CDAD was associated with a greater median length of mechanical ventilation (25 hours versus 12 hours, p < 0.001), longer intensive care unit stay (5 days versus 2 days, p < 0.001), and extended hospital stay (21 days versus 7 days, p < 0.001), with no difference in 30-day mortality (7.6% versus 9.5%, p = 0.80). CONCLUSIONS: Although the overall incidence of CDAD was low, alteration in transfusion practices and antibiotic utilization may impact the development of CDAD among cardiac surgical patients.

BACKGROUND: Excellent outcomes after aortic valve replacement (AVR) in elderly patients can be achieved, yet some practitioners are reticent to refer elderly patients for surgery. This study analyzed risk factors for mortality in patients aged 80 years and older undergoing AVR with or without concomitant coronary artery bypass grafting (CABG). METHODS: A retrospective review was performed of 245 patients (129 women) with a mean age of 83.6 +/- 2.9 years who had AVR with (n = 140) or without CABG (n = 105) at a single institution from 1993 to 2005. Data were analyzed with a multivariate logistic regression for predictors of operative mortality, Kaplan-Meier estimates of survival, and a Cox multivariate proportional analysis of factors influencing long-term survival. RESULTS: Mean preoperative New York Heart Association (NYHA) classification was 3.1 +/- 0.9, and 78% (192/245) of patients were classified as NYHA class III or IV. Operative (30-day) mortality was 9% (22/245). Independent risk factors for operative mortality included postoperative renal failure (odds ratio [OR], 20.9; 95% confidence interval [CI], 6.5 to 67.6; p < 0.001), postoperative permanent stroke (OR, 11.3; 95% CI, 1.7 to 75.1; p = 0.019), or intraoperative/postoperative intraaortic balloon pump (IABP) placement (OR, 14.9; 95% CI 2.9 to 75.8; p = 0.002). Survival after surgery was 82% (n = 183) at 1 year and 56% (n = 88) at 5 years. Prognostic factors for decreased long-term survival were regurgitant valve pathology (hazard ratio [HR], 6.0; 95% CI, 2.5 to 14.2; p = 0.002), intraoperative/postoperative IABP (HR, 2.9; 95% CI, 1.4 to 6.0; p = 0.010), postoperative renal failure (HR, 3.5, 95% CI, 2.2 to 5.7; p < 0.001), and postoperative stroke (HR, 7.0, 95% CI, 3.2 to 15.9; p < 0.001). Performing concomitant CABG was protective in terms of operative mortality (OR, 0.3; 95% CI, 0.09 to 0.83; p = 0.017) and improved long-term survival (HR, 0.7, 95% CI, 0.47 to 0.96; p = 0.020). Preoperative NYHA classification did not affect operative or long-term survival. CONCLUSIONS: Patients aged 80 years and older who undergo AVR have acceptable short-term and long-term survival regardless of NYHA status. Concomitant CABG improved operative and long-term survival in this population. Despite their increased age, aggressive surgical treatment is warranted for most patients.

BACKGROUND: Severe neurologic complications after cardiac transplantation are devastating outcomes of this life-saving procedure. Incidence, risk factors, and morbidity of neurologic events in the modern era of cardiac transplantation are yet to be defined. METHODS: Between 1996 and 2005, 200 patients (64% men; mean age, 49 +/- 12 years) underwent heart transplantation at our institution. Overall, 46 patients (23%) showed a wide spectra of early neurologic complications. RESULTS: Cause of ischemic complications was stroke in 11 patients (7 had concomitant epileptic seizures) and transient ischemic attack (TIA) in 7. Encephalopathy (n = 10), epileptic seizures unrelated to focal cerebral lesions (n = 7), severe headache (n = 6), cerebral infection (n = 3), and peripheral nervous system injuries (n = 2) completed the spectra of adverse neurologic outcomes. Multivariate analysis identified advanced age (p = 0.03), preoperative left ventricular assist device support (p = 0.02), preoperative intraaortic balloon pump support (p < 0.001), prolonged cardiopulmonary bypass time (p < 0.001), and postoperative hepatic failure (p = 0.04) as independent predictors of early neurologic complications. Postoperative morbidities associated with neurologic complications included longer ventilation time (p < 0.001), longer stay in the intensive care unit (p < 0.001), and higher incidence of pneumonia (p < 0.001) and sepsis (p = 0.01) compared with patients without neurologic events. There was a trend toward higher in-hospital mortality (15% versus 6%, p = 0.07), but there was no difference in long-term survival (65% versus 78%, p = 0.15). CONCLUSIONS: Despite rigorous pretransplantation screening, neurologic complications were common after cardiac transplantation. Most frequently, these complications were not the actual cause of death, but they significantly contributed to increased morbidity. Preoperative mechanical circulatory support requirement was the strongest predictor for adverse neurologic outcome.

BACKGROUND: The optimal perfusion strategy during surgery of acute type A aortic dissection is controversial. The purpose of this study was to determine the impact of retrograde cerebral perfusion during hypothermic circulatory arrest on short-term and long-term outcome in this specific patient population. METHODS: Between 1984 and 2005, 175 consecutive patients underwent repair of an acute type A dissection. Three different surgical approaches were used: aortic cross-clamping without hypothermic circulatory arrest in 50 (29%), hypothermic circulatory arrest alone in 69 (39%), and hypothermic circulatory arrest with supplemental retrograde cerebral perfusion in 56 (32%). RESULTS: Operative mortality was 18% +/- 3% (+/- 70% confidence interval), and adverse outcomes (death or cerebrovascular accident) occurred in 21% +/- 3% of patients (p = 0.97 between groups). Multivariate analysis identified valve replacement (p = 0.04), preoperative flow complications (p = 0.03), and non-Marfan syndrome (p = 0.04) as predictors of operative mortality. Intraoperative dissection (p < 0.001) and history of cerebrovascular disease (p = 0.02) were predictors for permanent neurologic deficit, and retrograde cerebral perfusion was shown to have a protective effect on transient neurologic deficits (p = 0.008). Kaplan-Meier survival was 75% +/- 3% at 1 year (131 patients at risk), 63% +/- 4% at 5 years (87 patients at risk), and 49% +/- 4% at 10 years (48 patients at risk) and was independent of surgical approach (p = 0.37). Long-term survival was diminished with increased age (p < 0.001), earlier operative year (p < 0.001), and coronary artery disease (p = 0.02). CONCLUSIONS: The current investigation suggests improved neurologic recovery with circulatory arrest and supplemental retrograde cerebral perfusion. Operative mortality and long-term survival were comparable among groups.