Faculty Bibliography

BACKGROUND: Numerous studies have developed a 'severity score' or 'risk index' for short-term mortality associated with coronary artery bypass graft (CABG) surgery, but very few studies have developed risk indices derived from statistical models to predict outcomes for cardiac valve replacement patients. METHODS: Data from New York's Cardiac Surgery Reporting System in 2001 to 2003 were used to develop statistical models that predict mortality for valve surgery and for valve/CABG surgery. These models were used to develop risk indices based on the type of valve surgery performed and several patient risk factors. The fit of each index was tested by examining the correspondence of expected and observed mortality rates for various risk score ranges using New York data between 1998 and 2000. RESULTS: There were a total of 11 risk factors for valve patients without CABG surgery and 12 risk factors for patients with both valve and CABG surgery. Risk factors represented measures of demographics, type of valve surgery, previous open heart surgery, ventricular function, hemodynamic state, and various comorbidities. Possible variable scores ranged from 0 to 7 in the isolated valve model and 0 to 5 in the valve/CABG model. The highest overall risk scores possible for the two models were 49 for isolated valve surgery and 35 for valve/CABG surgery, and the highest scores observed for any patient were 32 and 26, respectively. CONCLUSIONS: These valve surgery risk indices will enable providers to estimate patients' short-term mortality risk and allow for comparisons of valve surgery outcomes with other regions

OBJECTIVES: The purpose of this research was to develop a risk index for in-hospital mortality for coronary artery bypass graft (CABG) surgery. BACKGROUND: Risk indexes for CABG surgery are used to assess patients' operative risk as well as to profile hospitals and surgeons. None has been developed using data from a population-based region in the U.S. for many years. METHODS: Data from New York's Cardiac Surgery Reporting System in 2002 were used to develop a statistical model that predicts mortality and to create a risk index based on a relatively small number of patient risk factors. The fit of the index was tested by applying it to another year (2003) of New York data and testing the correspondence of expected and observed mortality rates for each risk score in the index. RESULTS: The risk index contains a total of 10 risk factors (age, female gender, hemodynamic state, ejection fraction, pre-procedural myocardial infarction, chronic obstructive pulmonary disease, calcified ascending aorta, peripheral arterial disease, renal failure, and previous open heart operations). The score possible for each variable ranges from 0 to 5, and total risk scores possible range from 0 to 34. The highest score observed for any patient was 22, and 93% of the patients had scores of 8 or lower. When the risk index was applied to another year of New York data with a considerably lower mortality rate, the C-statistic was 0.782. CONCLUSIONS: The risk index appears to be a valuable tool for predicting patient risk when applied to another year of New York data. It should now be tested against other risk indexes in a variety of geographical regions

BACKGROUND: Several studies have compared outcomes for coronary-artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), but most were done before the availability of stenting, which has revolutionized the latter approach. METHODS: We used New York's cardiac registries to identify 37,212 patients with multivessel disease who underwent CABG and 22,102 patients with multivessel disease who underwent PCI from January 1, 1997, to December 31, 2000. We determined the rates of death and subsequent revascularization within three years after the procedure in various groups of patients according to the number of diseased vessels and the presence or absence of involvement of the left anterior descending coronary artery. The rates of adverse outcomes were adjusted by means of proportional-hazards methods to account for differences in patients' severity of illness before revascularization. RESULTS: Risk-adjusted survival rates were significantly higher among patients who underwent CABG than among those who received a stent in all of the anatomical subgroups studied. For example, the adjusted hazard ratio for the long-term risk of death after CABG relative to stent implantation was 0.64 (95 percent confidence interval, 0.56 to 0.74) for patients with three-vessel disease with involvement of the proximal left anterior descending coronary artery and 0.76 (95 percent confidence interval, 0.60 to 0.96) for patients with two-vessel disease with involvement of the nonproximal left anterior descending coronary artery. Also, the three-year rates of revascularization were considerably higher in the stenting group than in the CABG group (7.8 percent vs. 0.3 percent for subsequent CABG and 27.3 percent vs. 4.6 percent for subsequent PCI). CONCLUSIONS: For patients with two or more diseased coronary arteries, CABG is associated with higher adjusted rates of long-term survival than stenting

BACKGROUND: Restriction of volume-based referral for CABG surgery to high-risk patients has been suggested, and earlier studies have reached different conclusions regarding volume-based referral for low-risk patients. METHODS AND RESULTS: Patients who underwent isolated CABG surgery in New York from 1997 through 1999 (n=57 150) were separated into low-risk and moderate-to-high-risk groups with a predicted probability of in-hospital death of 2% as the cutoff point. The provider volume-mortality relationship was examined for both groups. For annual hospital volume thresholds between 200 and 600 cases, the adjusted ORs of in-hospital mortality for high-volume to low-volume hospitals ranged from 0.45 to 0.77 and were all significant for the low-risk group; for the moderate-to-high-risk group, ORs ranged from 0.62 to 0.91, and most were significant. The number needed to treat at higher-volume hospitals to avoid 1 death was greater for the low-risk group (a range of 114 to 446 versus 37 to 184). As the annual surgeon volume threshold increased from 50 to 150 cases, the ORs for high- to low-volume surgeons increased from 0.43 to 0.74 for the low-risk group; for the moderate-to-high-risk group, ORs ranged from 0.79 to 0.86. Compared with patients treated by surgeons with volumes of <125 in hospitals with volumes of <600, patients treated by higher-volume surgeons in higher-volume hospitals had a significantly lower risk of death; in particular, the OR was 0.52 for the low-risk group. CONCLUSIONS: For both low-risk and moderate-to-high-risk patients, higher provider volume is associated with lower risk of death

Both the mutational status and the specific mutation of TP53 (p53) have been shown to impact both tumor prognosis and response to therapies. Molecular profiling of solid tumors is confounded by infiltrating wild-type cells, since normal DNA can interfere with detection of mutant sequences. Our objective was to identify TP53 mutations in 138 stage I-IV colorectal adenocarcinomas and liver metastases without first enriching for tumor cells by microdissection. To achieve this, we developed a harmonized protocol involving multiplex polymerase chain reaction/ligase detection reaction (PCR/LDR) with Universal DNA microarray analysis and endonuclease V/ligase mutation scanning. Sequences were verified using dideoxy sequencing. The harmonized protocol detected all 66 mutations. Dideoxy sequencing detected 41 out of 66 mutations (62%) using automated reading, and 59 out of 66 mutations (89%) with manual reading. Data analysis comparing colon cancer entries in the TP53 database (http://p53.curie.fr) with the results reported in this study showed that distribution of mutations and the mutational events were comparable

BACKGROUND: Recent evolution of minimally invasive technology has expanded the application of the right thoracotomy approach for mitral valve surgery. These same technological advances have also made the left posterior minithoracotomy approach attractive in complex mitral procedures. METHODS: From 1996 to 2003, 921 isolated mitral valve procedures were performed without sternotomy; 40 (4.3%) of these were performed via left posterior minithoracotomy. In the left posterior minithoracotomy group, ages ranged from 18 to 84 years; 36 patients had had previous cardiac surgery (9 on > or =2 occasions). Other factors precluding right thoracotomy included mastectomy/radiation and pectus excavatum. RESULTS: Arterial perfusion was via femoral artery (n = 26) or descending aorta (n = 14); long femoral venous cannulas with vacuum-assisted drainage were used in 39 procedures. Two patients had direct aortic crossclamping, 18 had hypothermic fibrillation, and 20 had balloon endoaortic occlusion. The mean crossclamp and bypass times were 81.9 and 117.2 minutes, respectively. Hospital mortality was 5.0% (2/40); both deaths occurred in octogenarians. There were no injuries to bypass grafts or conversions to sternotomy. Complications included perioperative stroke (2/40; 5.0%), bleeding (2/40; 5.0%), and respiratory failure (1/40; 2.5%); 28 patients (70%) had no postoperative complications. There was no incidence of perioperative myocardial infarction, renal failure, sepsis, or wound infection. The median length of stay was 7 days. CONCLUSIONS: Advances in minimally invasive cardiac surgery technology are readily adaptable to a left-sided minithoracotomy approach to the mitral valve. The left posterior minithoracotomy approach is a valuable option in complicated reoperative mitral procedures with acceptable perioperative morbidity and mortality

OBJECTIVES: This study was designed to compare in-hospital mortality and complications and three-year mortality and revascularization for off-pump and on-pump coronary artery bypass graft (CABG) surgery after adjusting for patient risk. BACKGROUND: The use of off-pump CABG surgery has increased tremendously in recent years, but little is known about its long-term outcomes relative to on-pump CABG surgery, and most studies have been very small. METHODS: Short- and long-term outcomes (inpatient mortality and complications, three-year risk-adjusted mortality, and mortality/revascularization) were explored for patients who underwent off-pump CABG surgery (9135 patients) and on-pump CABG surgery (59044 patients) with median sternotomy from 1997 to 2000 in the state of New York. RESULTS: Risk-adjusted inpatient mortality was 2.02% for off-pump versus 2.16% for on-pump (p = 0.390). Off-pump patients had lower rates of perioperative stroke (1.6% vs. 2.0%, p = 0.003) and bleeding requiring reoperation (1.6% vs. 2.2%, p < 0.001) and higher rates of gastrointestinal bleeding, perforation, or infarction (1.2% vs. 0.9%, p = 0.003). Off-pump patients had lower postoperative lengths of stay (median 5 days vs. 6 days, p < 0.001). On-pump patients had higher three-year survival (adjusted risk ratio [RR] =1.086, p = 0.045) and higher freedom from death or revascularization (adjusted RR = 1.232, p < 0.001). When analyses were limited to 1999 to 2000, the two-year adjusted hazard ratio for survival was not significant (adjusted RR = 0.99, p = 0.81). CONCLUSIONS: On-pump patients experience better long-term survival and freedom from revascularization than off-pump patients. However, the survival benefit from on-pump procedures was no longer present in the last two years of the study

OBJECTIVE: Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods. METHODS: Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. RESULTS: Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality. CONCLUSIONS: Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique