Training and Management of a Multisite Neuropsychological Testing Protocol for the Department of Veterans Affairs Cooperative Study Evaluating on- and Off-pump Coronary Artery Bypass Graft Procedures

Research study coordinators from 17 sites participating in a cardiac surgery study were trained to administer and score a brief neuropsychological test battery. Results were sent to the study's centralized laboratory for review and feedback. The average examiner errors on the first six protocols were compared with the average errors on the last six protocols over 12 months for each site. Overall, errors for the first six protocols were 4.42, and errors for the last six protocols were 1.83, representing a significant overall decline. Errors for instruction, administration, and recording showed a significant decrease over time. Despite ongoing feedback to examiners, scoring errors did not decline significantly overall; this suggests that a review of all protocols is necessary to achieve reliable scoring. However, when examiners' number of protocols completed was compared with number of scoring errors per protocol, there was a trend for examiners who had completed more protocols to show more improvement in scoring.

Changes in health-related quality of life following coronary artery bypass graft surgery

BACKGROUND

There are limited data to help clinicians identify patients likely to have an improvement in quality of life following CABG surgery. We evaluated the relationship between preoperative health status and changes in quality of life following CABG surgery.

METHODS

We evaluated 1,744 patients enrolled in the VA Cooperative Processes, Structures, and Outcomes in Cardiac Surgery study who completed preoperative and 6-month postoperative Short Form-36 (SF-36) surveys. The primary outcome was change in the Mental Component Summary (MCS) and Physical Component Summary (PCS) scores from the SF-36.

RESULTS

On average, physical and mental health status improved following the operation. Preoperative health status was the major determinant of change in quality of life following surgery, independent of anginal burden and other clinical characteristics. Patients with MCS scores less than 44 or PCS scores less than 38 were most likely to have an improvement in quality of life. Patients with higher preoperative scores were unlikely to have an improvement in quality of life.

CONCLUSIONS

Patients with preoperative health status deficits are likely to have an improvement in their quality of life following CABG surgery. Alternatively, patients with relatively good preoperative health status are unlikely to have a quality of life benefit from surgery and the operation should primarily be performed to improve survival.

Risk factors for intermediate-term survival after coronary artery bypass grafting

BACKGROUND

Risk factors for short-term mortality after coronary artery bypass grafting are well established, but little is known about risk factors for intermediate-term mortality.

METHODS

We analyzed the outcomes of 11,815 patients undergoing coronary artery bypass grafting in one of the 43 cardiac surgery programs of the Department of Veteran Affairs. Risk factors for intermediate- and short-term mortality were determined using Cox proportional hazards regression models. Effects of risk factors during these two periods were explicitly compared.

RESULTS

We found important differences in mortality risk-factor sets between the intermediate- and short-term periods after coronary artery bypass grafting. The majority of predictors of intermediate-term mortality were noncardiac-related variables, whereas the majority of predictors of short-term mortality were cardiac-related variables. Impaired functional status, chronic obstructive pulmonary disease, and renal dysfunction had greater effects in the intermediate-term period. Previous heart operation, angina class III or IV, previous myocardial infarction, and preoperative use of an intraaortic balloon pump had greater effects in the short-term period.

CONCLUSIONS

The risk factors for intermediate-term mortality identified in this study can augment preoperative risk assessment and counseling of patients. Clinicians should be aware of the importance of noncardiac-related variables as predictors of mortality in the intermediate-term period after coronary artery bypass grafting.

A decade's experience with quality improvement in cardiac surgery using the Veterans Affairs and Society of Thoracic Surgeons national databases

OBJECTIVE

To review the Department of Veteran Affairs (VA) and the Society of Thoracic Surgeons (STS) national databases over the past 10 years to evaluate their relative similarities and differences, to appraise their use as quality improvement tools, and to assess their potential to facilitate improvements in quality of cardiac surgical care.

SUMMARY BACKGROUND DATA

The VA developed a mandatory risk-adjusted database in 1987 to monitor outcomes of cardiac surgery at all VA medical centers. In 1989 the STS developed a voluntary risk-adjusted database to help members assess quality and outcomes in their individual programs and to facilitate improvements in quality of care.

METHODS

A short data form on every veteran operated on at each VA medical center is completed and transmitted electronically for analysis of unadjusted and risk-adjusted death and complications, as well as length of stay. Masked, confidential semiannual reports are then distributed to each program's clinical team and the associated administrator. These reports are also reviewed by a national quality oversight committee. Thus, VA data are used both locally for quality improvement and at the national level with quality surveillance. The STS dataset (217 core fields and 255 extended fields) is transmitted for each patient semiannually to the Duke Clinical Research Institute (DCRI) for warehousing, analysis, and distribution. Site-specific reports are produced with regional and national aggregate comparisons for unadjusted and adjusted surgical deaths and complications, as well as length of stay for coronary artery bypass grafting (CABG), valvular procedures, and valvular/CABG procedures. Both databases use the logistic regression modeling approach. Data for key processes of care are also captured in both databases. Research projects are frequently carried out using each database.

RESULTS

More than 74,000 and 1.6 million cardiac surgical patients have been entered into the VA and STS databases, respectively. Risk factors that predict surgical death for CABG are very similar in the two databases, as are the odds ratios for most of the risk factors. One major difference is that the VA is 99% male, the STS 71% male. Both databases have shown a significant reduction in the risk-adjusted surgical death rate during the past decade despite the fact that patients have presented with an increased risk factor profile. The ratio of observed to expected deaths decreased from 1.05 to 0.9 for the VA and from 1.5 to 0.9 for the STS.

CONCLUSION

It appears that the routine feedback of risk-adjusted data on local performance provided by these programs heightens awareness and leads to self-examination and self-assessment, which in turn improves quality and outcomes. This general quality improvement template should be considered for application in other settings beyond cardiac surgery.

Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity

BACKGROUND

The purpose of this study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) decreases risk-adjusted operative death and major complications after coronary artery bypass grafting in selected patients.

METHODS

Using The Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database, procedural outcomes were compared for conventional and off-pump CABG procedures from January 1, 1998, through December 31, 1999. Mortality and major complications were examined, both as unadjusted rates and after adjusting for known base line patient risk factors.

RESULTS

A total of 126 experienced centers performed 118,140 total CABG procedures. The number of off-pump CABG cases was 11,717 cases (9.9% of total cases). The use of an off-pump procedure was associated with a decrease in risk-adjusted operative mortality from 2.9% with conventional CABG to 2.3% in the off-pump group (p < 0.001). The use of an off-pump procedure decreased the risk-adjusted major complication rate from 14.15% with conventional CABG to 10.62% in the off-pump group (p < 0.0001). Patients receiving off-pump procedures were less likely to die (adjusted odds ratio 0.81, 95% CI 0.70 to 0.91) and less likely to have major complications (adjusted odds ratio 0.77, 95% CI 0.72 to 0.82).

CONCLUSIONS

Off-pump CABG is associated with decreased mortality and morbidity after coronary artery bypass grafting. Off-pump CABG may prove superior to conventional CABG in appropriately selected patients.

Off-pump coronary artery bypass is associated with improved risk-adjusted outcomes

BACKGROUND

The impact of off-pump median sternotomy coronary artery bypass grafting procedures on risk-adjusted mortality and morbidity was evaluated versus on-pump procedures.

METHODS

Using the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Program records from October 1997 through March 1999, nine centers were designated as having experience (with at least 8% coronary artery bypass grafting procedures performed off-pump). Using all other 34 Veterans Affairs cardiac surgery programs, baseline logistic regression models were built to predict risk of 30-day operative mortality and morbidity. These models were then used to predict outcomes for patients at the nine study centers. A final model evaluated the impact of the off-pump approach within these nine centers adjusting for preoperative risk.

RESULTS

Patients treated off-pump (n = 680) versus on-pump (n = 1,733) had lower complication rates (8.8% versus 14.0%) and lower mortality (2.7% versus 4.0%). Risk-adjusted morbidity and mortality were also improved for these patients (0.52 and 0.56 multivariable odds ratios for off-pump versus on-pump, respectively, p < 0.05).

CONCLUSIONS

An off-pump approach for coronary artery bypass grafting procedures is associated with lower risk-adjusted morbidity and mortality.

Localization of telomerase hTERT protein and survivin in placenta: relation to placental development and hydatidiform mole

OBJECTIVE

To find if a difference in telomerase or survivin expression exists between non-neoplastic tissues and hydatidiform moles, and explore expression of those proteins in normal placental development, post-term gestation, and preeclampsia.

METHODS

Formalin-fixed placental tissues were selected from collections of the Department of Pathology at the University of Colorado. Five specimens of each trimester, five each of preeclamptic and post-term placentas, and 23 molar pregnancies were selected. The telomerase catalytic protein hTERT was localized in placental tissues using the catalyzed signal amplification system, and survivin was localized by conventional immunoperoxidase method. Staining was graded on a scale of zero to 4.

RESULTS

hTERT staining was detected in sections of 42 of 48 specimens (23 of 23 hydatidiform moles, 19 of 25 non-neoplastic placental tissues). The intensity of staining for hTERT was higher in hydatidiform moles (mean 3.3, median 3) compared with levels in non-neoplastic placental tissues (mean 0.92, median 1) (P <.001). Survivin was detected in 39 of 48 specimens (22 of 23 hydatidiform moles, 17 of 25 non-neoplastic placental tissues). Compared with non-neoplastic tissues (mean 0.88, median 1), survivin levels were elevated in hydatidiform moles (mean 1.35, median 1) (P =.031).

CONCLUSION

Survivin and telomerase were increased in hydatidiform moles, suggesting that regulation of apoptosis and stabilization of telomere length might be involved in neoplastic transformation of the placenta. The patterns of expression observed for survivin and telomerase in non-neoplastic placental tissues suggest that the control of apoptosis and stabilization of telomeric DNA might also be involved in normal gestational development.

Effects of race, with or without gender, on operative mortality after coronary artery bypass grafting: a study using The Society of Thoracic Surgeons National Database

BACKGROUND

Although gender is known to be an independent predictor of 30-day operative mortality (OM) after coronary artery bypass grafting, the purpose of this study was to determine whether race-alone or in combination with gender-affects OM.

METHODS

For 1994 to 1996, The Society of Thoracic Surgeons database records for 441,542 coronary artery bypass grafting-only procedures were analyzed. Baseline annual multivariate models were built. Gender and race were added to each model. Risk-adjusted OM rates were then calculated for race, gender, and their combination. Patients were also stratified into groups of comparable predicted OM to allow for a direct comparison of risk-matched Caucasians and non-Caucasians.

RESULTS

Of the procedures, 28.2% were on women and 8.5% on non-Caucasians. Overall, OM was 3.29%. Multivariate risk-adjusted OM varied by gender and race (p < 0.10). Risk-adjusted OM rates (with 95% confidence intervals) were 4.0% (3.9% to 4.1%) for females and 3.2% (3.2% to 3.3%) for males. Risk-adjusted OM rates were 3.9% (3.7% to 4.1%) for non-Caucasians and 3.3% (3.2% to 3.3%) for Caucasians. Among equally risk-matched Caucasians and non-Caucasians, non-Caucasians had significantly higher (p < 0.005) mortality among the lower risk subgroups (up to 10% predicted OM) but not among the higher risk subgroups.

CONCLUSIONS

Race and gender are independent predictors of adverse outcome following coronary artery bypass grafting, holding all other risk factors constant.

Association of fast-track cardiac management and low-dose to moderate-dose glucocorticoid administration with perioperative hyperglycemia

OBJECTIVE

To delineate associations between preoperative risk factors and clinical processes of care and perioperative glucose tolerance in patients managed on a fast-track cardiac surgery clinical pathway with prebypass methylprednisolone administration.

DESIGN

Retrospective sequential cohort study.

SETTING

University-affiliated Department of Veterans Affairs medical center.

PARTICIPANTS

Fast-track patients (n = 293; n = 72 low-dose methylprednisolone [100-125 mg]; n = 221 moderate-dose methylprednisolone [500 mg]) plus pre-fast-track patients (n = 258; no methylprednisolone) undergoing cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Multivariate linear regression was used to model the association of 17 preoperative risk and intraoperative process-of-care variables with serum glucose concentration on arrival in the intensive care unit. Preoperative serum glucose concentrations were not significantly different among the pre-fast-track, fast-track with low-dose methylprednisolone, and fast-track with moderate-dose methylprednisolone cohorts (129 +/- 54, 137 +/- 55, 127 +/- 46 mg/dL [mean +/- SD]). Postoperative serum glucose concentrations were significantly different (171 +/- 58, 223 +/- 56, 250 +/- 75 mg/dL; p < 0.03, for all pairwise comparisons). Using backward elimination from the full 17-variable multivariate model (R-square = 0.63), 4 variables remained significant (all p < 0.0001; R-square = 0.60): (1) Preoperative diabetes status (adjusted mean post-operative glucose level, mg/dL; [95% confidence interval (CI)]): no treatment, 193 (188-199); oral agent, 276 (262-291); insulin requiring, 301 (283-320); (2) steroid group: pre-fast-track, 201 (195-209), fast-track with low-dose methylprednisolone, 271 (256-287); fast-track with moderate-dose methylprednisolone, 295 (284-306); (3) volume of glucose-containing cardioplegia (beta coefficient, 95% CI): 2.22% (1.37-3.10) increase per 100 mL; and (4) intraoperative epinephrine infusion: none, 231 (224-239); yes, 276 (264-288). No significant interactions were identified. No significant effect of opioid dose was observed.

CONCLUSION

At this institution, implementation of the fast-track pathway was associated with a deterioration of glucose tolerance. Preoperative diabetes, pre-cardiopulmonary bypass administration of steroids, volume of glucose-containing cardioplegia solution administered, and use of epinephrine infusions were significantly associated multivariate factors.

Identification of risk factors for increased cost, charges, and length of stay for cardiac patients

BACKGROUND

In this study we explored different risk model options to provide clinicians with predictions for resource utilization. The hypotheses were that predictors of mortality are not predictive of resource consumption, and that there is a correlation between cost estimates derived using a cost-to-charge ratio or a product-line costing approach.

METHODS

From March 1992 to June 1995, 2,481 University of Colorado Hospital patients admitted for ischemic heart disease were classified by diagnosis-related group code as having undergone or experienced coronary bypass procedures (CBP), percutaneous cardiovascular procedures (PCVP), acute myocardial infarction (AMI), and other cardiac-related discharges (Other). For each diagnosis-related group, Cox proportional hazards models were developed to determine predictors of cost, charges, and length of stay.

RESULTS

The diagnosis groups differed in the clinical factors that predicted resource use. As the two costing methods were highly correlated, either approach may be used to assess relative resource consumption provided costs are reconciled to audited financial statements.

CONCLUSIONS

To develop valid prediction models for costs of care, the clinical risk factors that are traditionally used to predict risk-adjusted mortality may need to be expanded.

Quantitative telomerase expression in glioblastomas shows regional variation and down-regulation with therapy but no correlation with patient outcome

Despite the nearly ubiquitous expression of telomerase in almost all types of malignant human tumors, studies have shown widely varying positivity in the highest-grade glioma, the glioblastomas (GBMs), ranging from 26% to 100% of tumors analyzed. We have previously shown significant variability in positive versus negative telomerase expression from region to region within the same GBM. In this study, we hypothesized that application of new quantitative methodology would extend our previous observations and identify whether there is heterogeneity in levels of protein expression even within areas positive for telomerase in high-grade gliomas. Finally, we sought to correlate quantitative telomerase expression with patient outcome and therapeutic response. Quantitative analysis was achieved by polymerase chain-based TRAP assay with phosphorimager analysis and compared with clinical information obtained from 19 patients, most with primary, untreated GBMs. Results showed up to 3-fold variability in telomerase levels across multiple regional samples from the same patient, as well as between patients. In 5 of 6 patients with recurrent tumors who had received intervening radiation therapy or chemotherapy, telomerase was downregulated in the second, post-therapy sample. These data provide in vivo corroboration of recent in vitro experiments showing telomerase downregulation after radiation therapy or chemotherapy treatment of cell lines. Our finding of variability in levels of telomerase expression in GBMs parallels the known heterogeneity of these tumors for histologic features and cell growth-related factors. Statistical analysis showed no relationship between TRAP score and either time to clinical progression or time to death.

Mild renal failure is associated with adverse outcome after cardiac valve surgery

The present study was performed to ascertain whether the presence of mild renal failure (defined as a serum creatinine concentration of 1. 5 to 3.0 mg/dL) is an independent risk factor for adverse outcome after cardiac valve surgery. An extensive set of preoperative and postoperative data was collected in 834 prospectively evaluated patients undergoing cardiac valve surgery at 14 Veterans Affairs Medical Centers. Univariate and multivariable analyses were performed to determine whether an independent association of mild renal dysfunction with adverse outcomes was present. Patients with mild renal failure had significantly greater 30-day mortality rates (P = 0.001; 16% versus 6%) and frequency of postoperative bleeding (P = 0.023; 16% versus 8%), respiratory complications (P = 0.02, 29% versus 16%), and cardiac complications (P = 0.002; 18% versus 7%) than patients with normal renal function (serum creatinine <1.5 mg/dL) when controlling for multiple other variables. The presence of a serum creatinine concentration of 1.5 to 3.0 mg/dL is significantly and independently associated with adverse outcomes after cardiac valve surgery.

MRI findings in haemophilic joints treated with radiosynoviorthesis with development of an MRI scale of joint damage

We hypothesized that magnetic resonance imaging (MRI) scans taken prior to radiosynoviorthesis may be predictive of response to the procedure in persons with haemophilia. Specifically, response would be inversely related to the severity of synovial hyperplasia. Radiosynoviorthesis was administered to 21 joints with recurrent haemorrhage (target joints). A detailed self-report of haemorrhage history, joint evaluation with scoring according to the World Federation of Haemophilia orthopaedic joint and pain scales, plain radiographs, and MRI studies of the joints were performed pre- and post-radiosynoviorthesis. To augment comparison of the MRI findings to those assessed using the Arnold-Hilgartner and Pettersson scales, a provisional MRI scale for evaluation of haemophilic arthropathy was designed. We found the MRI findings prior to the procedure were not predictive of clinical response; independent of the severity of synovial hyperplasia, most joints bled less and showed improvement by the WFH orthopaedic score. There was generally no change in the severity of synovial hyperplasia after the procedure. We conclude that MRI evaluation is not routinely indicated prior to radiosynoviorthesis.

Clinical science research

Clinical science research incorporates the fields of clinical investigation and health services research. With a focus on the use of either human specimens or subjects, clinical investigation research projects translate knowledge gained from basic science research based on animal models for disease. The goal of clinical investigation is to develop new prevention, intervention, and therapeutic approaches to improve patient clinical outcomes. In contrast, health services research focuses on the improvement of the efficacy, cost-effectiveness, and outcomes of care. Health services research projects examine options to improve the health care delivery system, organization, financing, and reimbursement mechanisms in place today. The purpose of this article is to review common terminology and methodologic approaches that are used in clinical science research. The process of designing a research project is reviewed. Beginning with the development of a research question and hypothesis, the steps for successful completion of the project are discussed. Different study design approaches are presented with their respective strengths and weaknesses. The challenges associated with conducting a clinical research study are discussed, including the development of an appropriate sampling strategy, the designing of data collection, instruments, and the assurance of study data integrity. Possible threats to study validity and generalizability are assessed.One the major advantages of clinical research is that it offers an opportunity to study clinical questions in the clinical setting without the expenses of a basic research laboratory and basic science technology. Thus important clinical questions related to patient care, new technology assessment, clinical practice management, health care administration, or health policy may be addressed.

The STS National Database: current changes and challenges for the new millennium. Committee to Establish a National Database in Cardiothoracic Surgery, The Society of Thoracic Surgeons

BACKGROUND

The Society of Thoracic Surgeons (STS) established the National Database (NDB) for Cardiac Surgery in 1989. Since then it has grown to be the largest database of its kind in medicine. The NDB has been one of the pioneers in the analysis and reporting of risk-adjusted outcomes in cardiothoracic surgery.

METHODS AND RESULTS

This report explains the numerous changes in the NDB and its structure that have occurred over the past 2 years. It highlights the benefits of these changes, both to the individual member participants and to the STS overall. Additionally, the vision changes to the NDB and reporting structure are identified. The individuals who have participated in this effort since 1989 are acknowledged, and the STS owes an enormous debt of gratitude to each of them.

CONCLUSIONS

Because of their collective efforts, the goal to establish the STS NDB as a "gold standard" worldwide for process and outcomes analysis related to cardiothoracic surgery is becoming a reality.

Stroke in cardiac surgical patients: determinants and outcome

BACKGROUND

Despite improving outcomes in cardiac surgical patients, stroke continues to remain a major complication. Few prospective studies are available on postoperative stroke. The present study was conducted to elucidate the incidence and predictors of stroke in a large group of cardiac surgical patients.

METHODS AND RESULTS

Prospective data collected on 4,941 patients undergoing cardiac surgery were subjected to univariate and logistic regression analyses (98.4% men; 72% older than 60 years; 9.1% with history of prior stroke; 80.4% underwent isolated coronary artery bypass grafting). Stroke predictors include history of stroke and hypertension, older age, systolic hypertension, bronchodilator and diuretic use, high serum creatinine, surgical priority, great vessel repair, use of inotropic agents after cardiopulmonary bypass, and total cardiopulmonary bypass time (p < 0.05 for all comparisons). Median intensive care unit and hospital stays were longer, and hospital mortality and 6-month mortality were higher for patients with stroke (p < 0.001).

CONCLUSIONS

Stroke after cardiac surgical procedures is a morbid event. Identification of predictors and development of strategies to modify these factors should lead to a lower incidence of stroke.

Telomerase is a highly sensitive and specific molecular marker in fine-needle aspirates of breast lesions

PURPOSE

Telomerase has been detected in a majority of human malignant tumors, making telomerase activity (TA) one key difference between mortal and immortal cells. In this study, we evaluated in blind-trial fashion the association of TA with cytologic and final clinical/pathologic diagnosis in fine-needle aspirates (FNAs) of breast lesions.

MATERIALS AND METHODS

In 172 FNAs, including 80 samples that were cytologically malignant, 18 that were atypical but not diagnostic for malignancy, and 74 that were cytologically benign, TA was determined by a modified nonradioactive telomeric repeat amplification protocol (TRAP) assay. Final diagnosis was made by pathologic examination of follow-up surgical material available for all the cytologically malignant samples, a majority of the cytologically atypical samples, and a portion of the cytologically benign samples.

RESULTS

TA was detected in 85 of 172 samples. Comparison of the cytologic and histologic diagnoses with TA showed that 80 of 87 samples from patients with breast cancer were telomerase-positive, resulting in a sensitivity of 92%. TA was found in four of five FNAs from carcinomas that were considered cytologically atypical but not diagnostic for malignancy. Eighty of 85 samples from patients with benign breast lesions were telomerase-negative, revealing a specificity of 94%. The five positive cases in this group were all fibroadenomas with low TA. Among the 18 cases with a cytologic diagnosis of atypia, there was a strong positive relationship between TRAP findings and histologic diagnosis.

CONCLUSION

The detection of TA in FNAs of breast lesions is a highly sensitive and specific marker of malignancy and may be used as an adjunct in cases with an equivocal cytologic diagnosis.

Health-related quality of life as a predictor of mortality following coronary artery bypass graft surgery. Participants of the Department of Veterans Affairs Cooperative Study Group on Processes, Structures, and Outcomes of Care in Cardiac Surgery

CONTEXT

Health-related quality of life has not been evaluated as a predictor of mortality following coronary artery bypass graft (CABG) surgery. Evaluation of health status as a mortality predictor may be useful for preoperative risk stratification.

OBJECTIVE

To determine whether the Physical and Mental Component Summary scores from the preoperative Short-Form 36 (SF-36) health status survey predict mortality following CABG surgery after adjustment for known clinical risk variables.

DESIGN

Prospective cohort study conducted between September 1992 and December 1996.

SETTING

Fourteen Veterans Affairs hospitals.

PATIENTS

Of the 3956 patients undergoing CABG surgery only and who were enrolled in the Processes, Structures, and Outcomes of Care in Cardiac Surgery study, the 2480 who completed a preoperative SF-36.

MAIN OUTCOME MEASURE

All-cause mortality within 180 days after surgery.

RESULTS

A total of 117 deaths (4.7%) occurred within 180 days of CABG surgery. The Physical Component Summary of the preoperative SF-36 was a statistically significant risk factor for 6-month mortality after adjustment for known clinical risk factors for mortality following CABG surgery. In multivariate analysis, a 10-point lower SF-36 Physical Component Summary score had an odds ratio (OR) of 1.39 (95% confidence interval [CI], 1.11-1.77; P=.006) for predicting mortality. The SF-36 Mental Component Summary score was not associated with 6-month mortality in multivariate analyses (OR, 1.09; 95% CI, 0.92-1.29; P=.31).

CONCLUSIONS

The Physical Component Summary score from the preoperative SF-36 is an independent risk factor for mortality following CABG surgery. The baseline Mental Component Summary score does not appear to be predictive of mortality. Preoperative patient self-report of the physical component of health status may be helpful for risk stratification and clinical decision making for patients undergoing CABG surgery.

The 1996 coronary artery bypass risk model: the Society of Thoracic Surgeons Adult Cardiac National Database

BACKGROUND

The Society of Thoracic Surgeons Adult Cardiac National Database has recently completed the update for the 1996 risk model to be used to estimate the risk of operative death for isolated coronary artery bypass graft (CABG) procedures.

METHODS

We placed emphasis on clinical relevance, data quality, data completeness, and univariate analyses. A logistic regression approach was used to develop the 1996 CABG-only risk model.

RESULTS

Odds ratios for the factors with highest risk are multiple reoperations (OR = 4.3), emergent salvage status (OR = 3.7), and first reoperation (OR = 2.7). Standard performance measures indicated the model had high predictive power and an acceptable level of calibration after adjustment for a large sample size effect.

CONCLUSION

The most current STS risk model of CABG operative mortality is a reliable and statistically valid tool. The 1996 CABG-only model has been approved for use by The Society of Thoracic Surgeons.

Renal failure predisposes patients to adverse outcome after coronary artery bypass surgery. VA Cooperative Study #5

BACKGROUND

More than 600,000 coronary artery bypass graft (CABG) procedures are done annually in the United States. Some data indicate that 10 to 20% of patients who are undergoing a CABG procedure have a serum creatinine of more than 1.5 mg/dl. There are few data on the impact of a mild increase in serum creatinine concentration on CABG outcome.

METHODS

We analyzed a Veterans Affairs database obtained prospectively from 1992 through 1996 at 14 of 43 centers performing heart surgery. We compared the outcome after CABG in patients with a baseline serum creatinine of less than 1.5 mg/dl (median 1.1 mg/dl, N = 3271) to patients with a baseline serum creatinine of 1.5 to 3.0 mg/dl (median 1.7, N = 631).

RESULTS

Univariate analysis revealed that patients with a serum creatinine of 1.5 to 3.0 mg/dl had a higher 30-day mortality (7% vs. 3%, P < 0.001) requirement for prolonged mechanical ventilation (15% vs. 8%, P = 0.001), stroke (7% vs. 2%, P < 0.001), renal failure requiring dialysis at discharge (3% vs. 1%, P < 0.001), and bleeding complications (8% vs. 3%, P < 0.001) than patients with a baseline serum creatinine of less than 1.5 mg/dl. Multiple logistic regression analyses found that patients with a baseline serum creatinine of less than 1.5 mg/dl had significantly lower (P < 0.02) 30-day mortality and postoperative bleeding and ventilatory complications than patients with a serum creatinine of 1.5 to 3.0 mg/dl when controlling for all other variables.

CONCLUSION

These results demonstrate that mild renal failure is an independent risk factor for adverse outcome after CABG.

Part I. Telomerase levels in human metastatic brain tumors show four-fold logarithmic variability but no correlation with tumor type or interval to patient demise

Telomerase expression has been found in the majority of human neoplasms at their primary sites and, in some tumor types, has been correlated with patient prognosis. In part one of this two-part study, we investigated whether telomerase was expressed ubiquitously in metastases to the brain and whether varying levels of expression existed or correlated with patient prognosis. A second aim of this study was to acquire data on brain metastases preliminary to the investigation of whether the telomerase assay could be used for the detection of tumor cells in cerebrospinal fluid (CSF). We investigated 35 brain metastases utilizing the sensitive telomeric repeat amplification protocol (TRAP) assay coupled with densitometric quantitation of telomerase levels on frozen, banked tissue specimens. Specimens metastatic to the brain analyzed in this study included melanoma, adenocarcinoma, hepatocellular carcinoma, germ cell neoplasm, squamous cell carcinoma, osteogenic sarcoma, and secondary lymphoma. Telomerase was found in 32 of 35 metastases. Quantitation of the telomerase products showed a fourfold logarithmic variation, following standardization of protein concentrations. Levels of telomerase expression showed no statistical correlation with either tumor subtype or interval from date of procedure to patient demise. Interestingly, in two patients with two metastatic samples each taken at discordant times, the telomerase levels were higher in the metastasis specimen taken closer to the time of demise. This suggests a possible increase in telomerase level within a given patient's neoplasm as the disease became more advanced, although too few cases were available to reach a firm conclusion in this regard. We conclude that most brain metastases express telomerase, albeit at widely varying levels, which are not clearly correlated with patient survival. These results influence the potential utility of telomerase analysis for the detection of small numbers of metastatic tumor cells in CSF, as addressed in the companion manuscript.

Part II. Telomerase expression in cerebrospinal fluid specimens as an adjunct to cytologic diagnosis

The diagnosis of meningeal carcinomatosis hinges on the cytologic examination of cerebrospinal fluid (CSF), which has a known low sensitivity for the identification of malignant cells. Often only 'suspicious' or 'atypical' diagnoses can be rendered, and specimens are commonly unsatisfactory for evaluation due to poor morphologic preservation. Telomerase is widely expressed in most brain metastases, medulloblastomas, lymphomas, oligodendrogliomas, and is expressed focally in glioblastomas. Little is known about the level of telomerase expression in these tumors, except for brain metastases, where a four-fold variation in telomerase levels exists. In our laboratory, as few as ten carcinoma cells can be detected by a sensitive polymerase chain reaction-based assay, the telomeric repeat amplification protocol (TRAP), for telomerase, but it was unclear whether varying levels of telomerase expressed by different types of metastases would influence detection. Using the TRAP protocol, we studied 281 CSF samples from a wide variety of patients with neurologic and non-neurologic conditions for telomerase expression. An adjusted specificity of 90% and a sensitivity of 64% were achieved for detection of malignant cells in CSF by telomerase expression. The TRAP assay for telomerase detection may serve as an adjunct to the traditional examination of CSF. Neither previously documented four-fold variation in the levels of telomerase expression in brain metastases, high CSF protein levels nor high white blood cell counts precluded detection of malignant cells in CSF.

Creative payment strategy helps ensure a future for teaching hospitals

The Colorado Medicaid Program in years past relied on disproportionate share hospital (DSH) payment programs to increase access to hospital care for Colorado citizens, ensure the future financial viability of key safety-net hospitals, and partially offset the state's cost of funding the Medicaid program. The options to finance Medicaid care using DSH payments, however, recently have been severely limited by legislative and regulatory changes. Between 1991 and 1997, a creative Medicaid refinancing strategy called the major teaching hospital (MTH) payment program enabled $131 million in net payments to be distributed to the two major teaching hospitals in Colorado to provide enhanced funding related to their teaching programs and to address the ever-expanding healthcare needs of their low-income patients. This new Medicaid payment mechanism brought the state $69.5 million in Federal funding that otherwise would not have been received.

Infant heart transplantation: improved intermediate results

OBJECTIVES

Our objectives were to (1) review our experience with heart transplants in infants (age < 6 months), (2) delineate risk factors for 30-day mortality, and (3) compare outcomes between our early and recent experience.

METHODS

Records of all infants listed for transplantation in our center before September 1996 were analyzed. Early and recent comparisons were made between chronologic halves of the accrual period. Univariate analysis was used to analyze potential risk factors for 30-day mortality (categorical variables, Fisher's exact test; continuous variables, nonparametric Wilcoxon rank-sum test). Multivariable analysis included univariate variables with p values < or = 0.10. Actuarial survivals were estimated (Kaplan-Meier) and compared by the log-rank test.

RESULTS

Fifty-one of the 60 infants listed for transplantation were operated on (waiting list mortality 15%). Thirty-day mortality was 18% overall, 30% in the first 3 years and 10% in the last 3 years (p = 0.07). Sepsis was the commonest cause of early death (4/9). Univariate analysis suggested four potential risk factors for early death: preoperative mechanical ventilation (p = 0.01), prior sternotomy (p = 0.002), preoperative inotropic drugs (p = 0.08), and warm ischemia time (p = 0.08). Multivariable analysis indicated that prior sternotomy (p = 0.01) was an independent risk factor for 30-day mortality. Actuarial survivals were 80%, 78%, and 70% at 1, 2, and 3 years, and these figures improved between early and recent groups (p = 0.05). Late deaths were most commonly due to acute rejection (3/5).

CONCLUSIONS

Results of heart transplantation in infancy improve with experience. Prior sternotomy increases initial risk. Intermediate-term survival for infants with end-stage heart disease is excellent.

Detection of telomerase expression in fine-needle aspirations and fluids

The cytologic examination of fine-needle aspirates and fluid specimens is plagued by a persistent false negative rate. The rate of false negative results will be decreased if sensitive molecular assays can be developed to detect cytologically malignant cells. The current study investigated telomerase expression as a potential marker of malignancy, using the telomeric repeat amplification protocol (TRAP) in fine-needle aspirates and fluid specimens. TRAP was performed on 24 fine-needle aspirate and 24 fluid specimens from different body sites and of different histological diagnoses. We found that 6 of 12 fine-needle aspirate specimens that were cytologically positive for malignant cells expressed telomerase activity, while no specimens that were cytologically suspicious for malignancy, atypical, or negative tested positive for telomerase activity. Of the fluid specimens, 4 of 6 cytologically positive cases and 1 of 18 cytologically negative cases expressed telomerase. Seven of eight telomerase negative, cytologically positive specimens contained only rare malignant cells in a very bloody background. Peripheral blood contamination is a possible pitfall in the TRAP assay, as applied in the current study, because the assay is standardized to protein concentration that may be derived from lysed red blood cells. We conclude that with further technical refinement, the TRAP assay could become a useful adjunct in the cytologic examination of fine-needle aspirates and fluid samples.

Early extubation following cardiac surgery in a veterans population

BACKGROUND

Early tracheal extubation is an important component of the "fast track" cardiac surgery pathway. Factors associated with time to extubation in the Department of Veterans Affairs (DVA) population are unknown. The authors determined associations of preoperative risk and intraoperative clinical process variables with time to extubation in this population.

METHODS

Three hundred four consecutive patients undergoing coronary artery bypass graft, valve surgery, or both on a fast track clinical pathway between October 1, 1993 and September 30, 1995 at a university-affiliated DVA medical center were studied retrospectively. After univariate screening of a battery of preoperative risk and intraoperative clinical process variables, stepwise logistic regression was used to determine associations with tracheal extubation < or = 10 h (early) or > 10 h (late) after surgery. Postoperative lengths of stay, complications, and 30-day and 6-month mortality rates were compared between the two groups.

RESULTS

One hundred forty-six patients (48.3%) were extubated early; one patient required emergent reintubation (0.7%). Of the preoperative risk variables considered, only age (odds ratio, 1.80 per 10-yr increment) and preoperative intraaortic balloon pump (odds ratio, 7.88) were multivariately associated with time to extubation (model R) ("late" association is indicated by an odds ratio >1.00; "early" association is indicated by an odds ratio <1.00). Entry of these risk variables into a second regression model, followed by univariately significant intraoperative clinical process variables, yielded the following associations (model R-P): age (odds ratio, 1.86 per 10-yr increment), sufentanil dose (odds ratio, 1.54 per 1-microg/kg increment), major inotrope use (odds ratio, 5.73), platelet transfusion (odds ratio, 10.03), use of an arterial graft (odds ratio, 0.32), and fentanyl dose (odds ratio, 1.45 per 10-microg/kg increment). Time of arrival in the intensive care unit after surgery was also significant (odds ratio, 1.42 per 1-h increment). Intraoperative clinical process variables added significantly to model performance (P < 0.001 by the likelihood ratio test).

CONCLUSIONS

In this population, early tracheal extubation was accomplished in 48% of patients. Intraoperative clinical process variables are important factors to be considered in the timing of postoperative extubation after fast track cardiac surgery.

Updates to the Data Quality Review Program: the Society of Thoracic Surgeons Adult Cardiac National Database

To ensure the credibility of this voluntary database, The Society of Thoracic Surgeons' National Database Audit and Validation Sub-Committee has been working during the past year to update and expand the group practice-based indicators used to assess the completeness, accuracy, and generalizability of the Adult Cardiac National Database. With increasing frequency, questions have been raised by third-party payors and regional/state-based groups as to the integrity of the data retained in the Adult Cardiac National Database. To work in conjunction with the Audit and Validation Sub-Committee to explicitly examine these issues, The Society of Thoracic Surgeons initiated a new Expert Advisory Panel review mechanism. This article describes the expanded data completeness and quality criteria that will be implemented in the coming year and summarizes the Expert Advisory Panel's recommendations for improvement.

Telomerase expression shows differences across multiple regions of oligodendroglioma versus high grade astrocytomas but shows correlation with Mib-1 labelling

AIMS/BACKGROUND

Telomerase is an enzyme that is expressed in most human neoplasms and is associated with tumour immortality. Determination of the point in neoplastic transformation at which telomerase is expressed may aid the understanding of tumour pathogenesis and progression. Despite numerous reports on telomerase, few studies have investigated its expression in high grade glial tumours. These studies, performed on archival banked, single brain tumour specimens, have shown conflicting results for oligodendrogliomas and unexpectedly negative results for telomerase expression in high grade astrocytomas, with one third to one half of glioblastoma multiformes being negative.

METHODS

34 rapidly banked glioma specimens taken from patients undergoing gross total surgical resection of their tumours were studied. Telomerase expression was assessed across 3-8 sampled regions from each tumour by the telomeric repeat amplification protocol (TRAP) assay. Matched mirror image tissue samples were taken for histological analysis of tissue adequacy, statistical correlation of telomerase with tumour histological features, Mib-1 (a marker for cell cycling) labelling, and p53 immunohistochemistry.

RESULTS

All five well differentiated oligodendrogliomas were homogeneously telomerase negative and two of three untreated anaplastic oligodendrogliomas were homogeneously positive. In contrast, 10 of 14 high grade astrocytomas showed heterogeneity for telomerase expression across the multiple regions sampled. All glioblastoma multiformes and two of three anaplastic astrocytomas showed at least one region positive for telomerase. When test samples were individually assessed in both oligodendrogliomas and high grade astrocytomas, telomerase expression was associated with Mib-1 labelling (p < 0.001). For the entire group, telomerase expression was associated with grade of tumour, age of patient, and vascular endothelial proliferation (all p < 0.001).

CONCLUSIONS

This regional study clarifies that all glioblastoma multiformes are at least focally positive and that telomerase expression correlates with tumour grade in oligodendrogliomas. Homogeneity versus heterogeneity for telomerase expression across multiple regions of oligodendrogliomas versus high grade astrocytomas may provide important preclinical data on the use of antitelomerase agents in these adult glial tumours.

1995 coronary artery bypass risk model: The Society of Thoracic Surgeons Adult Cardiac National Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac National Database has recently completed the development of the 1995 risk model to be used to estimate the risk of operative death for isolated coronary artery bypass graft (CABG) procedures. This article describes the detailed methodology used, as well as a new Expert Advisory Panel review mechanism that was initiated by The Society.

METHODS

Placing emphasis on clinical relevance, data quality, data completeness, and univariate analyses, a logistic regression analysis was used to develop the 1995 CABG-only risk model. The STS National Office invited an Expert Advisory Panel (composed of nationally recognized, independent biostatisticians) to review the modeling process used.

RESULTS

The 1995 CABG-only model details are reported. Standard performance measures indicated the model had high predictive power and an acceptable level of calibration. The Expert Advisory Panel reviewed the 1995 CABG model and concluded that the current modeling techniques were adequate. Suggestions for future model development and reporting were proposed by the Panel.

CONCLUSIONS

The most current STS risk model of CABG operative mortality is a reliable and statistically valid tool. Its development and performance have been critically examined and approved by an independent panel of experts.

Time series monitors of outcomes. A new dimension for measuring quality of care

OBJECTIVES

Despite the popularity of risk-adjusted outcomes as quality of health care indicators, their instability with time and their inability to provide reliable comparisons of small volume providers have raised questions about the feasibility and credibility of using these measures. In this article the authors describe a new analytic strategy to address these problems by examining risk-adjusted mortality with time, "Time Series Monitors of Outcome" (TSMO), and its application to cardiac surgery performed throughout the Department of Veterans Affairs between April 1987 and September 1992.

METHODS

Expected operative mortality for 24,029 patients undergoing coronary artery bypass surgery at all 43 centers performing this procedure was estimated using a logistic regression model to adjust for patient-specific risk factors. The ratio of observed-to-expected operative mortality was calculated for each hospital for each of the 11 6-month periods. Poisson regression models were used to identify high and low outlier hospitals based on significant deviation from the 5.5 year overall mean and/or the individual hospital's trend of observed-to-expected ratios with time.

RESULTS

This method identified four high and one low outlier hospitals based on significant deviations from the overall mean and three upward and seven downward trending outlier hospitals based on significant deviations in trend with time. A significant downward trend in observed-to-expected ratios of 4% per year also was observed for all coronary artery bypass graft procedures performed throughout the Department of Veterans Affairs during the last 5.5 year period.

CONCLUSIONS

Time Series Monitors of Outcome should help reduce misclassification of outliers due to random variation in outcomes as well as provide more reliable comparative information from which to evaluate provider performance.

Telomerase expression in normal epithelium, reactive atypia, squamous dysplasia, and squamous cell carcinoma of the uterine cervix

Telomerase activity has been detected in a broad range of human malignant neoplasms, and its expression may represent an essential step in the malignant transformation of tissues; however, the expression of telomerase in premalignant lesions remains relatively unexplored. We tested tissue sections of cervical squamous cell carcinomas and squamous intraepithelial lesions, samples of benign reactive atypia, and normal cervical mucosa from hysterectomy and cone biopsy specimens for the expression of telomerase. Mirror-image sections from each sample were paraffin embedded and processed for histologic analysis. The test samples of cervical tissue were crushed under liquid nitrogen, and telomerase activity was determined by the telomeric repeat amplification protocol. Telomerase activity was detected in 18 of 18 cases (100%) of invasive squamous cell carcinoma. Twenty-five of 26 samples (96%) of high-grade squamous intraepithelial lesion also tested positively for telomerase activity, including 10 of 10 samples of moderate dysplasia, 12 of 13 samples of severe dysplasia, and 3 of 3 samples of carcinoma in situ. Telomerase activity was detected in 14 of 25 samples (56%) of low-grade squamous intraepithelial lesion and in 10 of 18 samples (56%) of reactive atypia but was detected in only 9 of 50 samples (18%) of histologically normal cervical mucosa. These results suggest that telomerase expression may be a marker of premalignant and malignant squamous cell lesions of the uterine cervix, although it is also expressed in a high proportion of cases of reactive atypia.

Detection of human papillomavirus in squamous cell carcinomas of the lung by polymerase chain reaction

Existing evidence supports the hypothesis that human papillomavirus (HPV) may play an etiologic role in the malignant transformation of squamous epithelial cells. Although HPV DNA has been identified in a high proportion of squamous cell carcinomas (SCC) of the cervix, anorectum, skin, and upper airways, few studies have tested for HPV in SCC of the lung. To confirm the presence of HPV in lung SCC, we tested for HPV DNA extracted from formalin-fixed tissues of 34 patients by polymerase chain reaction (PCR). DNA amplification was performed using HPV L1 consensus sequence primers (MY11 and MY09; Perkin-Elmer Cetus, Norwalk, CT) which recognize a broad spectrum of HPV types including 6, 11, 16, 18, 31, and 33, among many other known types, as well as at least 20 other unidentified types. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization with [32P]-labeled generic HPV probes. HPV DNA positive cases were subsequently analyzed by slot-blot hybridization of the PCR products with specific probes for HPV types 6, 11, 16, 18, and 33. HPV type 18 was detected in two cases, including one case from a 44-year-old female and one from a 64-year-old male, with the remaining 32 cases negative. In situ hybridization for HPV DNA failed to detect HPV types 6/11, 16/18, or 31/33/35 in any of the cases. We conclude that a small proportion of cases of primary pulmonary SCC test positive for HPV type 18 but that the great majority of cases are not associated with HPV.

Atrial fibrillation after cardiac surgery: a major morbid event?

OBJECTIVE

The purpose of the study was to investigate the incidence, predictors, morbidity, and mortality associated with postoperative atrial fibrillation (AF) and its impact on intensive care unit (ICU) and postoperative hospital stay in patients undergoing cardiac surgery in the Department of Veterans Affairs (VA).

SUMMARY BACKGROUND DATA

Postoperative AF after open cardiac surgery is rather common. The etiology of this arrhythmia and factors responsible for its genesis are unclear, and its impact on postoperative surgical outcomes remains controversial. The purpose of this special substudy was to elucidate the incidence of postoperative AF and the factors associated with its development, as well as the impact of AF on surgical outcome.

METHODS

The study population consisted of 3855 patients who underwent open cardiac surgery between September 1993 and December 1996 at 14 VA Medical Centers. Three hundred twenty-nine additional patients were excluded because of lack of complete data or presence of AF before surgery, and 3794 (98.4%) were male with a mean age of 63.7+/-9.6 years. Operations included coronary artery bypass grafting (CABG) (3126, 81%), CABG + AVR (aortic valve replacement) (228, 5.9%), CABG + MVR (mitral valve replacement) (35, 0.9%), AVR (231, 6%), MVR (41, 1.06%), CABG + others (95, 2.46%), and others (99, 2.5%). The incidence of postoperative AF was 29.6%. Multivariate logistic regression analysis of factors found significant on univariate analysis showed the following predictors of postoperative AF: preoperative patient risk predictors: advancing age (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.48-1.75, p < 0.001), chronic obstructive pulmonary disease (OR 1.37, 95% CI 1.12-1.66, p < 0.001), use of digoxin within 2 weeks before surgery (OR 1.37, 95% CI 1.10-1.70, p < 0.003), low resting pulse rate <80 (OR 1.26, 95% CI 1.06-1.51, p < 0.009), high resting systolic blood pressure >120 (OR 1.19, 95% CI 1.02-1.40, p < 0.026), intraoperative process of care predictors: cardiac venting via right superior pulmonary vein (OR 1.42, 95% CI 1.21-1.67, p < 0.0001), mitral valve repair (OR 2.86, 95% CI 1.72-4.73, p < 0.0001) and replacement (OR 2.33, 95% CI 1.55-3.55, p < 0.0001), no use of topical ice slush (OR 1.29, 95% CI 1.10-1.49, p < 0.0009), and use of inotropic agents for greater than 30 minutes after termination of cardiopulmonary bypass (OR 1.36, 95% CI 1.16-1.59, p < 0.0001). Postoperative median ICU stay (3.6 days AF vs. 2 days no AF, p < 0.001) and hospital stay (10 days AF vs. 7 days no AF, p < 0.001) were higher in AF. Morbid events, hospital mortality, and 6-month mortality were significantly higher in AF (p < 0.001): ICU readmission 13% AF vs. 3.9% no AF, perioperative myocardial infarction 7.41 % AF vs. 3.36% no AF, persistent congestive heart failure 4.57% AF vs. 1.4% no AF, reintubation 10.59% AF vs. 2.47% no AF, stroke 5.26% AF vs. 2.44% no AF, hospital mortality 5.95% AF vs. 2.95% no AF, 6-month mortality 9.36% AF vs. 4.17% no AF.

CONCLUSIONS

Atrial fibrillation after cardiac surgery occurs in approximately one third of patients and is associated with an increase in adverse events in all measurable outcomes of care and increases the use of hospital resources and, therefore, the cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

Fast-track cardiac surgery in a Department of Veterans Affairs patient population

BACKGROUND

"Fast-track" (FT) cardiac surgery is popular in the private and university sectors. This study was designed to examine its safety and efficacy in the Department of Veterans Affairs elderly, male patient population, a population with multiple comorbid risk factors, often decreased social functioning, and impaired support systems.

METHODS

Time to extubation, hospital length of stay, perioperative morbidity, and mortality were studied in two consecutive cohorts undergoing cardiac operations requiring cardiopulmonary bypass before (pre-FT: n = 255, January 1992 to September 1993) and after (FT: n = 304, October 1993 to October 1995) institution of an FT protocol at a university-affiliated teaching Department of Veterans Affairs medical center. Preoperative risk factors, including a Department of Veterans Affairs risk-adjusted estimate of operative mortality, and perioperative surgical and anesthetic processes of care were evaluated.

RESULTS

The mean Department of Veterans Affairs risk estimate of perioperative mortality was not different between the pre-FT and FT cohorts (3.5% versus 3.7%, p = 0.13). In the FT cohort, median time to extubation decreased significantly (19.2 versus 10.2 hours; p < 0.001) along with median surgical intensive care unit stay (96 versus 49 hours; p < 0.001) and total postoperative length of stay (222 versus 167 hours; p < 0.001). Median postoperative day of hospital discharge decreased from day 10 to 7 (p < 0.001). One patient (0.3%) required emergent reintubation directly related to early extubation. Reintubation for medical reasons was unchanged between pre-FT and FT groups (6.3% versus 5.0%; p = 0.48). Postoperative morbidity was similar between groups except for nosocomial pneumonia, the rate of which decreased significantly in the FT cohort (14.7% versus 7.3%; p < 0.005). Thirty-day (3.9% versus 4.6%; p = 0.69) and 6-month mortality (6.7% versus 6.9%; p = 0.91) were unchanged.

CONCLUSIONS

An FT cardiac surgery protocol has been instituted in a university-affiliated teaching Department of Veterans Affairs medical center, with decreased length of stay and no significant increase in postoperative morbidity, 30-day mortality, or 6-month mortality. It was associated with a lower rate of nosocomial pneumonia, a finding that must be validated in a prospective study.

Telomerase expression in normal endometrium, endometrial hyperplasia, and endometrial adenocarcinoma

Telomerase activity has been detected in a broad range of human cancers and its expression could be an important step in tumor progression. Here, telomerase activity by the telomeric repeat amplification protocol in cases of benign endometrium, endometrial hyperplasia, and endometrial adenocarcinoma was tested. Telomerase expression was detected in 13 of 14 cases of proliferative phase endometrium, in 7 of 12 cases of secretory phase endometrium, but was not detected in any of 7 cases of atrophic endometrium. Three of three cases with evidence of luteal phase defect and one of four cases of chronic endometritis also expressed telomerase activity. Hyperplastic endometrium was positive for telomerase in 13 of 17 cases. Telomerase activity was detected in 40 of 48 cases of endometrial adenocarcinoma, which included 36 of 43 cases of endometrioid adenocarcinoma and four of five cases of papillary serous carcinoma. The detection of telomerase in endometrial adenocarcinoma was not associated with either architectural grade, myometrial invasion, or stage. There was statistically significant association, however, between telomerase activity in benign atrophic endometrium versus any endometrial abnormality in women 52 years of age or older.

Telomerase activity in benign and malignant thyroid tumors

Thyroid nodules are found in 5% to 10% of the population. While these nodules carry only a 5% to 10% risk of malignancy, tests that complement fine-needle aspiration (FNA) cytology in preoperative diagnosis and risk stratification are lacking. Telomerase is a ribonucleoprotein polymerase with activity found in many malignant tissues, but absent from most normal adult tissue. In this study, we have investigated telomerase activity in 24 thyroid tumors, 14 matched adjacent thyroid tissues, and 3 chronic thyroiditis tissue samples. Using a telomeric repeat amplification protocol (TRAP) assay on frozen tissue, telomerase activity was detected in 11 of 20 thyroid carcinomas, including 10 of 14 papillary carcinomas and a Hurthle cell carcinoma. Telomerase activity was not detected in 4 benign adenomas, 3 follicular carcinomas, or a single case each of medullary and anaplastic thyroid carcinoma. Telomerase activity was detected in 3 of 14 samples of adjacent thyroid tissue from patients with thyroid tumors. Interestingly, all 3 cases of adjacent thyroid tissue that tested positive had a moderate to marked degree of chronic inflammation. In addition, 3 of 3 samples from chronic thyroiditis specimens tested positive for telomerase activity. When tumor invasiveness (vascular and/or capsular) was compared with telomerase activity in papillary carcinomas, only 1 of 4 telomerase-negative tumors was invasive, while 6 of 10 of telomerase-positive tumors were invasive. Moreover, 6 of 7 invasive papillary carcinomas had telomerase activity. In summary, this is the first report of telomerase activity in thyroid tissue and nodules. This activity was detected in a large percentage of papillary thyroid carcinomas, but not benign adenomas, follicular carcinomas, or most normal thyroid tissue. Telomerase activity may also correlate with tumor invasiveness. Further studies will focus on larger numbers of tumors, metastatic tissue, and undifferentiated carcinomas, as well as application of this assay to products from fine-needle aspirates as a potential diagnostic and prognostic marker in thyroid neoplasms.

Telomerase expression in human breast cancer with and without lymph node metastases

Telomerase is a ribonucleoprotein enzyme that synthesizes telomeric DNA onto the ends of chromosomes, thereby preventing the replication-dependent shortening of these ends. Telomerase activity is detected in a wide range of cancers of various tissues, and its expression may be a critical step in tumor progression. The telomeric repeat amplification protocol was used to compare telomerase activity in breast cancers with and without lymph node metastases, as well as in fibroadenomas and normal breast tissue. Expression of telomerase was detected in 22 (79%) of 28 primary breast cancers, which included 16 (73%) of 22 cancers positive and 6 (100%) of 6 cancers negative for axillary lymph node metastases. It was detected in 1 (11%) of 9 fibroadenomas but was negative in 13 normal breast tissues. There was no statistical difference in expression of telomerase between axillary node-negative primary breast cancers and similar tumors with nodal metastasis (P = .289). Further, no statistical association was found between telomerase activity and tumor size (P = .679) or hormonal status (P = .178). The difference in telomerase activity among breast cancers vs fibroadenomas and normal breast tissues, however, was statistically significant (P < .001). Although normal breast tissue does not express telomerase, both node-positive and node-negative breast cancers express telomerase. The possible significance of telomerase expression in fibroadenomas remains open to further investigation.

The Society of Thoracic Surgeons National Cardiac Surgery Database: current risk assessment

BACKGROUND

The Society of Thoracic Surgeons National Cardiac Surgery Database has recently completed gathering patient data from 1990 through 1994. Using information from more than 300,000 patients undergoing isolated coronary artery bypass grafting in this period, new risk models of operative mortality were developed.

METHODS

Logistic regression analysis was used to develop a risk model for each calendar year. A standard "training set/test set" approach was used for each model.

RESULTS

Five validation techniques were used to evaluate the reliability of the risk models. All models were found to predict operative mortality with good accuracy in this population.

CONCLUSIONS

The new risk models for isolated coronary artery bypass operations serve as reliable predictors of operative mortality for the most recent harvest of patient data from The Society of Thoracic Surgeons National Cardiac Surgery Database.

Calculating risk and outcome: the Veterans Affairs database

The methodology used by the Department of Veterans Affairs for data collection and analysis to derive observed/expected mortality ratios in cardiac surgical patients is reviewed. The Department of Veterans Affairs' use of univariate and multivariate analysis to develop risk ratios for individual risk factors is described. Its experience with tracking observed/expected mortality and morbidity associated with cardiac surgery and length of hospital stays is reviewed. Results of the Department of Veterans Affairs study of the relationship between hospital surgical volume and observed/expected ratios are reported. Feasible goals for the improvement of the predictive capability of database models and the limitations affecting model accuracy are discussed.

Data quality review program: the Society of Thoracic Surgeons Adult Cardiac National Database

In summary, the National Database Committee's Audit and Validation Subcommittee is working to maximize the data completeness and quality of the STS National Database. Toward this end, we welcome your suggestions for improvement.

No continuous relationship between Veterans Affairs hospital coronary artery bypass grafting surgical volume and operative mortality

BACKGROUND

The purpose of this study was to determine whether risk-adjusted coronary artery bypass grafting mortality rates are significantly related to coronary artery bypass grafting surgical procedure volume within the Department of Veterans Affairs hospital system.

METHODS

From April 1987 to September 1992, expected mortality rates were calculated for 23,986 coronary artery bypass grafting procedures performed at 44 different Veterans Affairs hospitals.

RESULTS

This study found a statistically significant relationship between annual hospital coronary artery bypass grafting volume and observed mortality rates (p < 0.02). However, no statistically significant relationship between coronary artery bypass grafting volume and risk-adjusted operative mortality was found (p = 0.10). Using analysis of variance on hospital-level data, hospitals with 100 or less cases per year have higher observed to expected mortality ratios than hospitals performing more than 100 cases per year (p = 0.03). Using Poisson regression models, however, a volume threshold could not be found.

CONCLUSIONS

These findings are consistent with the current Veterans Affairs policy requirements to periodically review quality at low-volume hospitals.

Quality initiatives and the power of the database: what they are and how they run

The criteria by which healthcare is judged or measured are quality, accessibility, and cost effectiveness. To evaluate these criteria it is important to have a database. There are many strengths and weakness to large databases. They can be used as an indicator of the level of performance or quality, for clinical decision making, and as a measurement of cost effectiveness. They can also be useful in the evaluation and development of treatment algorithms and critical pathways for patients with entry level disease. In addition, they can measure patient access to healthcare and the appropriateness of care. It is important for these databases to appropriately adjust for preoperative risk factors that may influence outcome. Outcome in most of the databases is measured by mortality, but morbidity, functional status, quality of life, cost of care, length of stay, return to work, and patient satisfaction are also important outcomes. Factors that can influence the quality of the outcome data are the methods by which the data are collected, standardization of definitions, the currentness of the database, adequate numbers of patients and outcomes, and appropriate analytic techniques. It is important to feed back the data to the healthcare providers in a timely enough fashion so that processes and structures of care can be modified to improve treatment and results. The reliability of the databases and the validity must be substantiated for the healthcare provider to have confidence in the database.(ABSTRACT TRUNCATED AT 250 WORDS)

Statistical methods and strategies for working with large data bases

This article describes the statistical methods and strategies to be used in establishing the linkages between processes and structures of care with risk-adjusted outcomes in a large multicenter Veterans Affairs cooperative study in health services of patients undergoing cardiac surgery. The statistical analyses consist of test involving nine specific hypotheses related to the effect of processes and structures of care on risk-adjusted outcomes. From the statistical point of view, the major obstacles of this study are the need for data reduction and imputation of missing data. The former obstacle is addressed through the use of data-reduction techniques, such as principal components and cluster of variables. The latter is addressed through the use of classic and new techniques for imputation of missing data, such as MISSGEN, principal components for qualitative data, and the expectation and maximization algorithm. Data reduction and imputation of missing data are done with clinically derived variable groups called "dimensions" or "subdimensions." The effect of processes and structures of care is assessed by a two-step process. First, outcomes are modeled using only patient risk factors. The selection of risk factors in the modeling process is discussed in detail. Second, these risk-adjusted outcomes are modeled using one of the nine process or structure subhypotheses. The relationship of the processes and structures of care dimensions and/or subdimensions that are linked to risk-adjusted outcomes are identified.

Variations in the processes and structures of cardiac surgery nursing care

Nurses play an invaluable role as key members of the cardiac surgery patient's medical care team. Over the last century, the nursing profession has become more independent and autonomous. Despite the widespread use of nursing quality indicators, the effect of nursing-specific processes and structures of care on patient outcomes is unknown. Thus, the Processes, Structures, and Outcomes of Care in Cardiac Surgery (PSOCS) study was initiated, in part, to determine the potential effect of nursing processes and structures of care on cardiac surgery patients' risk-adjusted outcomes. In this article, the authors summarize the key components of nursing structures of care incorporated in the PSOCS study. Nursing process variables were not sufficiently designed into the study to address hypotheses relating nursing care processes to patient outcomes. An analysis of the pilot test data from September 1992 to September 1993 demonstrated potentially important variations between the six pilot centers regarding nursing care provider profiles (eg, educational preparation, specialty certification, and experience levels) and nursing staff ratios (eg, within the surgical intensive care unit). When linked to risk-adjusted patient outcomes, these variations in nursing structure of care may offer important insights toward improving the quality of care of cardiac surgery patients.

Why it is important to demonstrate linkages between outcomes of care and processes and structures of care

This first article of the supplement describes the rationale for the Department of Veterans Affairs Cooperative Study, Processes, Structures, and Outcomes in Cardiac Surgery, which was designed to demonstrate statistically and clinically meaningful linkages between processes and structures of care and the outcomes of that care. United States health care is in an era of great enthusiasm for the use of health care outcomes to assess and improve quality of care. An important reason for this enthusiasm is the concern that processes and structures of care, which traditionally have been selected arbitrarily without valid linkages to favorable outcomes, may not result in the desired outcomes of care. Furthermore, health care outcomes are intrinsic to the definition of quality of care and should be relatively free of preconceived biases about how care should be provided. However, the limitations to outcomes-directed quality improvement have been inadequately recognized. These limitations include the following: (1) mortality, the most commonly used outcome, is usually sufficiently rare, resulting in inadequate statistical power; (2) nonfatal outcomes are much more difficult to measure reliably; (3) outcomes may not be measurable for an extended period of time after the care episode, making linkage to quality improvement inefficient; and (4) patients often desire good processes of care as well as favorable outcomes. A review of the literature found relatively few reports linking processes and structures of care to favorable outcomes. Significant relationships between processes of care and outcomes have been reported for several medical conditions (congestive heart failure, acute myocardial infarction, pneumonia, and stroke) when the patient has been considered the unit of analysis. However, there is a paucity of published meaningful process-outcome or structure-outcome linkages for surgical conditions or for any conditions when the hospital has been the focus of analysis. The authors concluded that quality improvement will proceed most efficiently and effectively if all three elements of Donabedian's quality triad (processes, structures, and outcomes) are used and if the processes and structures chosen have been demonstrated to be associated with desired outcomes of care.

An analysis of interobserver reliability and representativeness of data from the Veterans Affairs Cooperative Study on Processes, Structures, and Outcomes in Cardiac Surgery

The authors made some preliminary judgments regarding the reliability and representativeness of the data in the early stages of the Veterans Affairs Cooperative Study entitled Processes, Structures, and Outcomes of Care in Cardiac Surgery (PSOCS). Preliminary PSOCS interobserver reliability and potential patient and site selection bias reported were based on comparisons with identical risk, procedure, and outcome data items collected independently in the Continuous Improvement in Cardiac Surgery Study. PSOCS interobserver reliability for this limited set of variables was good to excellent. At the six pilot centers, there were few important differences between patients entered into PSOCS and those not entered. The 14 Veterans Affairs medical centers that will participate in the full-scale PSOCS study and the 29 nonparticipating centers exhibited similar patient populations. will be valuable.