Clinical outcomes of aneurysmal subarachnoid hemorrhage patients treated with oral diltiazem and limited intensive care management.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) patients are frequently treated with prophylactic nimodipine and undergo invasive monitoring of blood pressure and volume status in an intensive care unit (ICU) setting to decrease the incidence of delayed ischemic neurological deficit (DIND) and improve functional outcomes. The goal of this study was to examine the incidence of DIND and poor functional outcomes in a consecutive series of SAH patients treated with a different regimen of prophylactic oral diltiazem and limited use of intensive care monitoring. METHODS: The study involved a consecutive series of 123 aneurysmal SAH patients treated by the senior author who were admitted within 72 hours of hemorrhage and who never received nimodipine or nicardipine. Functional outcomes were graded using the Glasgow Outcome Scale (GOS). RESULTS: Of the 123 patients identified, favorable outcomes (GOS 4 and 5) were achieved in 74.8%. The incidence of DIND was 19.5%. Hypertensive, hypervolemic, hemodilutional (HHH) therapy was used in 10 patients (8.1%) and no patients were treated for DIND by endovascular means. Seven patients (5.7%) had a poor functional outcome or death because of DIND and two of these were related to complications of HHH therapy. These results were compared to contemporary series of SAH patients managed with other treatment protocols. CONCLUSIONS: Functional outcomes of patients treated with a regimen of oral diltiazem, limited use of ICU monitoring and HHH therapy for DIND compare favorably with other contemporary series of SAH patients.

Aortic valve replacement: current clinical practice and opportunities for quality improvement.

This is a review of the current clinical practice and opportunities for quality improvement in aortic valve replacement surgery. The topics include trends and regional variation in procedure rates, and changes in the use of aortic valve replacement among the elderly. Recent developments guiding the choice of prosthetic valves and trends in in-hospital mortality rates for aortic valve surgery are summarized. Lastly, a discussion of topics relevant to clinical practice improvement including the implementation of clinical practice guidelines, the need for consensus on risk adjustment, better understanding of volume-outcome effects, and the opportunities for comprehensive assessment of aortic valve surgery.

Decreasing mortality for aortic and mitral valve surgery in Northern New England. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: Although numerous reports have documented declining mortality rates associated with coronary artery bypass surgery in recent years, it is unknown whether similar trends have occurred with valve surgery during this time. METHODS: We conducted a regional, prospective study to assess trends in patient casemix and in-hospital mortality rates over time with aortic valve replacement (AVR), mitral valve replacement (MVR), and mitral valve repair. Data were collected from all patients undergoing AVR (n = 2,596), MVR (n = 759), or mitral valve repair (n = 522) in Northern New England between January 1992 and December 1997. Logistic regression was used to identify significant predictors of in-hospital mortality and to calculate risk-adjusted mortality rates. RESULTS: For AVR, the trend in patient casemix was toward increased risk with increases in patient age and in the proportion of patients with: body surface area less than 1.7, diabetes, coronary artery disease, and prior valve surgery. A decrease was noted in the proportion of patients undergoing additional surgical procedures. For MVR, patient risk improved over the time period with fewer female patients and fewer patients with coronary artery disease. For mitral valve repair patient risk increased over the time period with increases in the proportion of patients with coronary artery disease, diabetes, and whose surgical priority was classified as urgent. In addition, there was a borderline significant increase in the proportion of mitral valve repair patients in New York Heart Association class IV preoperatively. Risk-adjusted mortality decreased 44% from 9.3% in 1992 through 1993 to 5.3% in 1996 through 1997 for patients undergoing AVR (p = 0.01) and decreased 53% from 13.6% in 1992 through 1993 to 8.2% in 1996 through 1997 for patients undergoing MVR (p = 0.01). We observed a statistically insignificant increase in risk-adjusted mortality over the time period for patients undergoing mitral valve repair (from 3.6% in 1992 through 1993 to 5.0% in 1996 through 1997; p = 0.34). CONCLUSIONS: Significant improvement in mortality rates with valve replacement was observed in northern New England during this time period. This improvement persisted following adjustment for changes in patient casemix over this time. These trends mirror improvements in mortality with other cardiac surgical interventions that have been observed in recent years in our region and nationally.

The impact of spinal problems on the health status of patients: have we underestimated the effect?

STUDY DESIGN: A prospective study of 17,774 patients who consulted spine centers in which the impact of spinal disorders and comorbidities on physical functional status were evaluated. OBJECTIVES: To quantify the effect spinal diagnoses have on patients' physical functional status (SF-36 Physical Component Summary [PCS] score) compared with other common conditions and to quantify the effects of comorbidities on physical functional status in spine patients. SUMMARY OF BACKGROUND DATA: The burden of spinal conditions on a patient's function and the role that comorbidities play in this affliction are poorly quantified in the literature. METHODS: Data from the Health Survey Questionnaire were prospectively gathered through the National Spine Network, a nonprofit consortium of spine-focused practices. Each patient's SF-36 score was summarized into a single PCS score. The correlation between diagnosis and comorbidity and PCS score was assessed using multivariate linear regression. RESULTS: The study patients were a mean of 47.5 years of age, 54.7% were female, 52.3% had lumbosacral diagnoses, and 82.0% had had 3 or more months of pain. The population had a mean PCS score of 30.4 +/- 9.95 (SD) compared with 50.0 +/- 10.00 for the general United States population. The more comorbidities in a patient, the lower the PCS score (Spearman rank correlation = -0.27). The five comorbid conditions that lowered the PCS the most included congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), renal failure, rheumatoid arthritis, and lupus (all P <0.001). In multiple linear regression analysis, age, gender, diagnosis, and comorbidity explained 12.1% of the variance in PCS score. CONCLUSIONS: The PCS score is greatly affected in patients with spinal problems. The study population's PCS (30.4) was lower or similar to the PCS for patients with other illnesses reported in the literature: CHF (31.0), COPD (33.9), SLE (37.1), cancer (38.4), primary total hip arthroplasty (29.0), primary total knee arthroplasty (32.6), and glenohumeral degenerative joint disease (35.2). Further, the presence of comorbidity in spine patients adds to the burden of spinal conditions on functional status.

Risks of morbidity and mortality in dialysis patients undergoing coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: Although dialysis patients are undergoing CABG with increasing frequency, large studies specifically comparing patient characteristics and procedure-related risks in this population have not been performed. METHODS AND RESULTS: We conducted a regional prospective cohort study of 15,500 consecutive patients undergoing CABG in northern New England from 1992 to 1997. We used multiple logistic regression analysis to examine associations between preoperative dialysis-dependent renal failure and postoperative events and to adjust for potentially confounding variables. The 279 dialysis-dependent renal failure patients (1.8%) were 4.4 times more likely to experience in-hospital mortality than were other CABG patients (12.2% versus 3.0%, respectively; P:<0.001). Dialysis-dependent renal failure patients were older and had more comorbidities and more severe cardiac disease than did other CABG patients. After adjusting for these factors in multivariate analysis, however, dialysis-dependent renal failure patients remained 3.1 times more likely to die after CABG (adjusted odds ratio [OR] 3.1, 95% CI 2.1 to 4.7; P:<0.001). Dialysis-dependent renal failure patients compared with other CABG patients also had a substantially increased risk of postoperative mediastinitis (3.6% versus 1.2%, respectively; adjusted OR 2.4, 95% CI 1.2 to 4.7; P:=0.011) and postoperative stroke (4.3% versus 1.7%, respectively; adjusted OR 2. 1, 95% CI 1.1 to 3.9; P:=0.016), even after controlling for potentially confounding variables. Risks of reexploration for bleeding were similar for patients with and without dialysis-dependent renal failure. CONCLUSIONS: Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and mediastinitis after CABG.

Prosthetic valve type for patients undergoing aortic valve replacement: a decision analysis.

BACKGROUND: In two large, randomized, clinical trials long-term survival after aortic valve replacement (AVR) was similar for patients receiving tissue and mechanical aortic heart valve prostheses. Higher bleeding rates among patients with mechanical valves, who must receive permanent oral anticoagulation to prevent thromboembolism, were offset by higher reoperation rates for valve degeneration among patients with tissue valves. Because the average age of patients undergoing AVR and clinical practices have changed considerably since the randomized clinical trials were conducted, we performed a decision analysis to reassess the optimal valve type for patients undergoing AVR. METHODS: We used a Markov state-transition model to simulate the occurrence of valve-related events and life expectancy for patients undergoing AVR. Probabilities of clinical events and mortality were derived from the randomized clinical trials and large follow-up studies. RESULTS: Although the two valve types were associated with similar life expectancy in 60-year-old patients (mean age of patients in the randomized clinical trials), tissue valves were associated with greater life expectancy than mechanical valves (10.7 versus 11.1 years) in 70-year-old patients (currently mean age of AVR patients). For 70-year-old patients, the effects of major bleeding complications (24%) with mechanical valves substantially outweighed those of reoperation for valve failure (12%) with tissue valves at 12 years. Of the clinical practice changes assessed, the recommended valve type was most sensitive to changes in bleeding rates with anticoagulation. However, bleeding rates would have to be 68% lower than those reported in the European randomized clinical trial to affect the recommended valve type for 70-year-old patients. Reoperation rates would have to be five times higher, and mortality rates at reoperation would have to be four times higher to affect the recommended valve type for 70-year-old patients. CONCLUSIONS: Although mechanical valves are preferred for AVR patients less than 60 years old, most patients currently undergoing AVR are elderly and would benefit more from tissue valves.

Trends in rates of reexploration for hemorrhage after coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: While mortality rates associated with coronary artery bypass grafting (CABG) have been declining, it is unknown whether similar improvements in the rates of morbidity have been occurring. This study examines trends in reexploration rates for hemorrhage, one of the serious complications of CABG surgery. It also explores changes in patient characteristics and several surgeon practice patterns potentially related to bleeding risks that may explain variations in these rates. METHODS: We performed a regional observational study of all of the 12,555 consecutive patients undergoing isolated CABG surgery in northern New England between 1992 and 1997. The rates of reexploration and patient characteristics were examined between two time intervals: period I (January 1, 1992 to June 1, 1994) and period II (June 1, 1995 to March 31, 1997). All of the region's 23 practicing surgeons responsible for these patients were surveyed to assess changes in practice patterns potentially related to bleeding risks. RESULTS: The adjusted rates of reexploration for bleeding declined 46% between periods I and II (3.6% versus 2.0%, p < 0.001). All of the five cardiac centers in northern New England showed similar trends with adjusted risk reductions ranging from 32% to 48% between the two time periods. This decline occurred despite the patients in period II having higher percentages of risk factors for reexploration for bleeding compared to patients in period I. From the surgeon survey, the number of surgeons using antifibrinolytics markedly increased from period I to period II. More surgeons were also using preoperative aspirin and heparin up until the time of surgery in period II. CONCLUSIONS: Similar to the rates of mortality, the rates of reexploration for bleeding following CABG surgery are substantially declining. This decrease in the reexploration rates occurred despite higher patient risks.

Is epsilon-aminocaproic acid as effective as aprotinin in reducing bleeding with cardiac surgery?: a meta-analysis.

BACKGROUND: Although aprotinin is known to be effective in reducing postoperative hemorrhage after cardiac surgery, epsilon-aminocaproic acid, an alternative antifibrinolytic, is considerably less expensive. Because the results of 3 small randomized clinical trials comparing these 2 agents directly were inconclusive, we performed a meta-analysis to compare the relative effectiveness and adverse-effect profile of these 2 agents against placebo. METHODS AND RESULTS: Data from 52 randomized clinical trials published between 1985 and 1998 involving the use of epsilon-aminocaproic acid (n=9) or aprotinin (n=46) in patients undergoing cardiac surgery were abstracted. Our primary outcomes were total blood loss, red blood cell transfusion rates and amounts, reexploration, stroke, myocardial infarction, and mortality. The meta-analysis revealed substantial reductions in total blood loss with epsilon-aminocaproic acid and low-dose aprotinin (each with a 35% reduction versus placebo, P<0.001) and high-dose aprotinin (53% reduction, P<0.001). There were identical reductions in total postoperative transfusions with epsilon-aminocaproic acid (61% reduction versus placebo, P<0. 010) and high-dose aprotinin (62% reduction, P<0.001). The proportion of patients transfused was similarly reduced with epsilon-aminocaproic acid (OR, 0.32; 95% CI, 0.15 to 0.69) and high-dose aprotinin (OR, 0.28; 0.22 to 0.37). Although both drugs reduced rates of reexploration to similar degrees, this effect was statistically significant only with high-dose aprotinin (OR, 0.39; 0. 24 to 0.61). epsilon-Aminocaproic acid and aprotinin had no effect on risks of postoperative myocardial infarction or overall mortality. CONCLUSIONS: Because the 2 antifibrinolytic agents appear to have similar efficacies, the considerably less-expensive epsilon-aminocaproic acid may be preferred over aprotinin for reducing hemorrhage with cardiac surgery.

Medical versus surgical treatment for low back pain: evidence and clinical practice.

CONTEXT: Although low back pain is one of the most common health problems, it is still difficult to choose between surgical and medical treatment. OBJECTIVE: To examine the evidence of the efficacy of surgical and medical treatment of the two most common indications for spinal surgery for low back pain--lumbar disc herniation and spinal stenosis--and to assess geographic variation in the use of surgery for these conditions in the United States. METHODS: The MEDLINE database (1966-1999) was searched for all studies that compared surgical and medical treatments for low back pain. Data from the Health Care Financing Administration were used to examine geographic variation in spinal surgery rates for patients enrolled in Medicare (1996-1997). RESULTS: Eight observational studies and one randomized clinical trial were identified. In general, these studies suggest better short-term outcomes (e.g., functional status and employability) with surgery than with medical approaches, but they indicate that long-term results are similar with both types of treatment. Methodologic flaws in the observational studies, particularly selection bias, preclude definitive conclusions about relative efficacy. In 1996 and 1997, more than 98,000 Medicare enrollees had surgery for disc herniation or spinal stenosis. Among hospital referral regions, rates of surgery for disc herniation varied 8-fold, from 0.24 to 1.96 per 1000 Medicare enrollees, and rates of surgery for spinal stenosis varied 12-fold, from 0.29 to 3.34 per 1000 Medicare enrollees. CONCLUSIONS: The literature comparing the efficacy of surgical and medical treatment for low back pain is limited. Not surprisingly, the use of surgery for low back pain varies widely across the United States. To establish clinical consensus, we need better evidence about the efficacy of surgery.

Results of a regional study of modes of death associated with coronary artery bypass grafting. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: It is well known that surgeon-specific in-hospital mortality rates for coronary artery bypass grafting vary, but this aggregate measure does not suggest specific opportunities for improvement. METHODS: We performed a regional prospective study of 8,641 consecutive patients undergoing isolated coronary artery bypass grafting by all of the 23 cardiothoracic surgeons practicing in northern New England during the study period. Mode of death was assigned by an end points committee using predetermined definitions. Surgeons were ranked according to risk-adjusted mortality rates and grouped in terciles, and cause-specific mortality rates were determined. RESULTS: The mortality rate was 3.3% in the lowest surgeon mortality tercile and 5.8% in the highest tercile. Fatal heart failure accounted for 80.0% of the difference in aggregate mortality rates, ranging from 1.9% in lowest surgeon mortality tercile to 4.0% in the highest tercile (p < 0.001). Rates of other causes did not differ significantly across surgeon mortality terciles. Differences in rates of fatal heart failure could not be explained by differences in preoperative left ventricular dysfunction or other patient characteristics. CONCLUSIONS: Most of the difference in observed mortality rates across surgeons is attributable to differences in rates of heart failure.

Variation in the management of pediatric splenic injuries in New Hampshire.

PURPOSE: The aim of this study was to determine if variation in the management of pediatric splenic injuries occurs among hospitals in New Hampshire. METHODS: Data accrued for each patient less than 18 years of age discharged from an acute care hospital in New Hampshire with a splenic injury diagnosis code or splenic procedure code were analyzed for the years 1991 through 1994. The splenectomy, splenorrhaphy, and nonoperative management rates of each hospital were analyzed and adjusted for case mix using direct standardization. Management rates were determined for patients with isolated splenic injuries, which were then adjusted for case mix. RESULTS: Variation in the management of pediatric splenic injuries was found to occur among hospitals in New Hampshire. Management variation persisted despite adjustment for case mix. Variation was also noted in the management of patients with isolated splenic injuries and persisted after case mix adjustment. CONCLUSION: Even after adjustment for case mix, if all children with splenic injuries in New Hampshire were treated in the same fashion as at the state's children's hospital, over 73% of splenectomies and 70% of splenorrhaphies performed for trauma may have been avoided.

Fate of the contralateral leg after infrainguinal bypass.

PURPOSE: To identify variables predictive of the need for future vascular intervention in a leg contralateral to one currently undergoing infrainguinal bypass. METHODS: We reviewed the records of 450 consecutively treated patients undergoing infrainguinal bypass for occlusive disease to examine the outcome of a previously untreated contralateral leg. Patients with coexistent contralateral limb-threatening ischemia at the time of initial ipsilateral operation were excluded, as were patients with bilateral disease who underwent a staged contralateral procedure within 3 months of the ipsilateral operation. This yielded a study cohort of 383 patients with no anticipated intervention in the contralateral leg who were followed for a mean value of 38 months. Patient survival and subsequent intervention in the contralateral leg were examined with life-table and regression analysis. RESULTS: Mean age of the patients was 68 years; 60% were men; 54% had diabetes; and 50% had coronary artery disease. The initial ipsilateral operation was performed for limb threat in 90% of instances. Twenty percent of patients subsequently needed intervention in the contralateral leg (infrainguinal bypass 83%, primary major amputation 17%). According to life-table analysis, 30% of patients needed intervention at 5 years, and the overall survival rate was 51% at 5 years. Multivariate analysis indicated that the need for future contralateral intervention was independently predicted with the following four risk factors: diabetes (relative risk [RR] 2.4x), coronary artery disease (RR 1.8x), lower initial ankle-brachial index (RR 2.1x with ankle-brachial index less than 0.7), and younger age (RR 2.2x if age less than 70 years). Regression models predicted the need for contralateral intervention for only 8% of patients at 5 years when none of these risk factors was present but for 67% when all risk factors were present. CONCLUSION: The fate of the contralateral leg after infrainguinal bypass is affected by diabetes, coronary artery disease, contralateral ankle-brachial index, and age at initial ipsilateral bypass. The effect of these risk factors is additive in prediction of the likelihood of future intervention. Knowledge of these factors may help identify instances in which the contralateral greater saphenous vein will be important for future limb salvage and also determine which patients need more careful follow-up care.

Obesity and risk of adverse outcomes associated with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: Obesity is frequently cited as a risk factor for adverse outcomes of major surgery. The results of prior studies of the relationship between obesity and risk of adverse outcomes of coronary artery bypass grafting (CABG) have been contradictory because of insufficient power to assess relatively infrequent outcomes or data to adjust for confounding factors. METHODS AND RESULTS: Data on patient age, sex, height, weight, medical history, current clinical status, and treatment factors were assessed prospectively among 11101 consecutive patients undergoing CABG. Body mass index (BMI) was used as the measure of obesity and was categorized as nonobese (1st to 74th percentiles), obese (75th to 94th percentiles), or severely obese (95th to 100th percentiles). Adverse outcomes occurring in-hospital, including mortality, intraoperative/postoperative cerebrovascular accident (CVA), postoperative bleeding, and sternal wound infection, were defined prospectively. Associations between obesity and postoperative outcomes were assessed by use of logistic regression to adjust for potentially confounding variables. Although obesity was not associated with increased mortality (adjusted odds ratio [OR], 1.16; P=.261) or postoperative CVA (adjusted OR, 1.06; P=.765), risks of sternal wound infection were substantially increased in the obese (adjusted OR, 2.10; confidence interval [CI], 1.45 to 3.06; P<.001) and severely obese (adjusted OR, 2.74; CI, 1.49 to 5.02; P=.001). On the other hand, rates of postoperative bleeding were significantly lower in the obese (adjusted OR, 0.66; CI, 0.49 to 0.90; P=.009) and severely obese (adjusted OR, 0.40; CI, 0.20 to 0.81; P=.011). CONCLUSIONS: With the exception of sternal wound infection, the perception among clinicians that obesity predisposes to various postoperative complications with CABG is not supported by these data. Further work is needed to understand the apparent protective effect of obesity on risks of postoperative bleeding.