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Background— The survival of patients who undergo aortic valve replacement (AVR) for severe aortic stenosis with reduced preoperative ejection fractions (EFs) is not well described in the literature. Methods and Results— Patients undergoing AVR for severe aortic stenosis were analyzed using the Northern New England Cardiovascular Disease Study Group surgical registry. Patients were stratified by preoperative EF (≥50%, 40%–49%, and P =0.003). Patients with preserved EF had significantly improved 6-month and 8-year survival compared with their reduced EF counterparts. Conclusions— Survival after AVR or AVR+coronary artery bypass grafting was most favorable among patients with preoperative preserved EF. However, patients with mild to moderately depressed EF experienced a substantial survival benefit compared with the natural history of medically treated patients. Furthermore, minor reductions of EF carried equivalent increased risk to those with more compromised function suggesting patients are best served when an AVR is performed before even minor reductions in myocardial function.

Background How best to define patient-prosthesis mismatch (PPM) continues to be debated. Over time, the indexed effective orifice area has become the most widely used method. However, the clinical relevance of PPM remains controversial. Methods The indexed geometric orifice area and indexed effective orifice area were calculated for 143 patients having undergone aortic valve replacement with a normal left ventricular function 0.45 or less. Using the indexed geometric orifice area method, PPM was defined as nonsignificant if 1.2 cm 2 /m 2 or greater and as significant if less than 1.2 cm 2 /m 2 . Using the indexed effective orifice area method, PPM was considered as nonsignificant if greater than 0.85 cm 2 /m 2 , as moderate if greater than 0.65 cm 2 /m 2 and less than or equal to 0.85 cm 2 /m 2 , and as severe PPM if 0.65 cm 2 /m 2 or less. Results The number of patients classified as having PPM differed according to the method used to predict its presence (PPM: Effective orifice area method=72.7%; geometric method=19.6%). Regardless of the method used to classify PPM there was no significant effect on mortality (adjusted hazard ratio: 2.65 at 1 year, 0.99 at 5 years, 0.92 at 9 years; p = not significant). The postoperative mean transvalvular gradient (17.1 ± 6.5 mm Hg) and left ventricular function (0.50 ± 0.145) improved significantly compared with the preoperative findings. Conclusions The method used to calculate PPM resulted in significant classification discordance. However, regardless of classification, the presence of PPM did not adversely affect long-term outcome.

Background Transfusion of red blood cells, while often used for treating blood loss or haemodilution, is also associated with higher infection rates and mortality. The authors implemented an initiative to reduce variation in the number of perioperative transfusions associated with cardiac surgery. Methods The authors examined patients undergoing non-emergent cardiac surgery at a single centre from the third quarter 2004 to the second quarter 2007. Phase I focused on understanding the current process of managing and treating perioperative anaemia. Phase II focused on (1) quality-improvement project dissemination to staff, (2) developing and implementing new protocols, and (3) assessing the effect of subsequent interventions. Data reports were updated monthly and posted in the clinical units. Phase III determined whether reductions in transfusion rates persisted. Results Indications for transfusions were investigated during Phase II. More than half (59%) of intraoperative transfusions were for low haematocrit (Hct), and 31% for predicted low Hct during cardiopulmonary bypass. 43% of postoperative transfusions were for low Hct, with an additional 16% for failure to diurese. The last Hct value prior to transfusion was noted (Hct 25–23, p=0.14), suggestive of a higher tolerance for a lower Hct by staff surgeons. Intraoperative transfusions diminished across phases: 33% in Phase I, 25.8% in Phase II and 23.4% in Phase III (p

Background Estimated glomerular filtration rate (eGFR) before coronary artery bypass graft (CABG) surgery is a key risk factor of in-hospital mortality. However, in patients with normal renal function before CABG, acute kidney injury develops after the procedure, making postoperative renal function assessment necessary for evaluation. Postoperative eGFR and its association with long-term survival have not been well studied. Methods We studied 13,593 consecutive CABG patients in northern New England from 2001 to 2006. Patients with preoperative dialysis were excluded. Data were linked to the Social Security Association Death Master File to assess long-term survival. Kaplan-Meier and log-rank techniques were used. Patients were stratified by established categories of postoperative eGFR (90 or greater, 60 to 89, 30 to 59, 15 to 29, and less than 15 mL · min −1 · 1.73 m −2 ). Results Median follow-up was 2.8 years (mean, 2.7; range, 0 to 5.5). Patients with moderate to severe acute kidney injury (less than 60) after CABG had significantly worse survival than patients with little or no acute kidney injury (90 or greater). Conclusions Patients having moderate to severe acute kidney injury after CABG surgery had worse 5-year survival compared with patients who had normal or near-normal renal function.

Background There is limited information comparing long-term survival after percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) in patients aged 80 years and older. We studied the long-term survival of octogenarians with multivessel coronary artery disease undergoing PCI or CABG who might have been candidates for either procedure. Methods We identified 1693 patients, aged 80 to 89, with two-vessel disease (57.6%) or three-vessel disease (42.4%), without left main disease, undergoing a first, nonemergency revascularization from 1992 to 2001. Adjusted hazard ratios (HR) were calculated for CABG versus PCI. Because survival curves for these procedures crossed midway through year 1, results were analyzed separately for the first 6 months and 6 months to 8 years. Results PCI was performed in 54.6% of patients with two-vessel disease and 23.7% of those with three-vessel disease. More CABG patients were men (54.7% versus 43.3%). The CABG patients had more peripheral vascular disease (23.1% versus 15.2%) and congestive heart failure (24.5% versus 13.1%) but less renal failure (4.6% versus 9.1%) and fewer prior myocardial infarctions (48.7% versus 53.6%). In-hospital mortality was 3.0% for PCI and 5.9% for CABG (p = 0.005). CABG was associated with poorer survival than PCI during the first 6 months (HR, 1.32; p = 0.135). Survival from 6 months to 8 years was significantly better with CABG for the group as a whole (HR, 0.72; p = 0.005) and for patients with two-vessel disease (HR, 0.68; p = 0.016), and there was a nonsignificant trend for those with three-vessel disease (HR, 0.75; p = 0.177). Conclusions Patients aged 80 years or older with multivessel disease must consider the trade-off between the increased early risks of CABG in return for improved long-term survival.

Stroke is a devastating complication of coronary artery bypass graft (CABG) surgery. In-hospital outcomes have been described, yet the long-term effect of stroke on mortality following CABG surgery has not been well studied.We examined the survival of 35,733 consecutive patients undergoing isolated CABG surgery in northern New England from 1992 through 2001. Stroke was defined as a new fixed neurologic defect that persisted at least 24 hours after surgery. Patient records were linked to the National Death Index to assess mortality. There were 147,931 person years of follow-up and 5,705 deaths. Cox proportional hazard regression was used to calculate the adjusted hazard ratios (HR) and 95% confidence intervals (95% CI). We identified the 5-year survival stratified by primary stroke mechanism, the patient's functional impact, and discharge location among a subset of patients who had strokes between 1992 and 2000.Perioperative stroke occurred in 575 patients (1.61%). Patients who had strokes had more comorbidities. After adjustments for differences in baseline patient and clinical characteristics, patients who had perioperative stroke were at a significantly increased risk for death (HR, 3.20; 95% CI, 2.80 to 3.66; p0.0001). Survival for patients with stroke at 1, 5, and 10 years was 83.0%, 58.7%, and 26.9%, respectively. Five-year survival decreased among patients who had major functional limitations before discharge, among those who had hypoperfusion strokes, and among patients who were discharged to locations other than home or rehabilitation facilities.Perioperative stroke is associated with a very substantial increased risk of postoperative death among CABG surgery patients. The greatest risk of death was noted within the first year after surgery. Survival after 1 year approximates that of patients who did not suffer a stroke.

Background Predicting risk for aortic and mitral valve surgery is important both for informed consent of patients and objective review of surgical outcomes. Development of reliable prediction rules requires large data sets with appropriate risk factors that are available before surgery. Methods Data from eight Northern New England Medical Centers in the period January 1991 through December 2001 were analyzed on 8,943 heart valve surgery patients aged 30 years and older. There were 5,793 cases of aortic valve replacement and 3,150 cases of mitral valve surgery (repair or replacement). Logistic regression was used to examine the relationship between risk factors and in-hospital mortality. Results In the multivariable analysis, 11 variables in the aortic model (older age, lower body surface area, prior cardiac operation, elevated creatinine, prior stroke, New York Heart Association [NYHA] class IV, congestive heart failure [CHF], atrial fibrillation, acuity, year of surgery, and concomitant coronary artery bypass grafting) and 10 variables in the mitral model (female sex, older age, diabetes, coronary artery disease, prior cerebrovascular accident, elevated creatinine, NYHA class IV, CHF, acuity, and valve replacement) remained independent predictors of the outcome. The mathematical models were highly significant predictors of the outcome, in-hospital mortality, and the results are in general agreement with those of others. The area under the receiver operating characteristic curve for the aortic model was 0.75 (95% confidence interval [CI], 0.72 to 0.77), and for the mitral model, 0.79 (95% CI, 0.76 to 0.81). The goodness-of-fit statistic for the aortic model was χ 2 [8 df] = 11.88, p = 0.157, and for the mitral model it was χ 2 [8 df] = 5.45, p = 0.708. Conclusions We present results and methods for use in day-to-day practice to calculate patient-specific in-hospital mortality after aortic and mitral valve surgery, by the logistic equation for each model or a simple scoring system with a look-up table for mortality rate.

Single-center studies suggest substantial variation in intraaortic balloon pump (IABP) utilization. Our purpose is to examine IABP utilization over time and across medical centers.This was a prospective cohort of 29,961 consecutive patients undergoing isolated coronary artery bypass graft surgery, between 1995 and 2000, at 10 centers (eight in northern New England and two in Canada).A total of 2,678 (8.9%) patients received an IABP. The rate of preoperative IABP insertion was 6.3%, and that of intra- or postoperative insertion was 2.6%. During the 6 years, IABP use increased from 7.0% to 10.3% (p(trend)0.001). Preoperative IABP insertion increased from 5.4% to 7.8% (p(trend)0.001). There was no significant increase in intra-/postoperative IABP insertion 1.7% to 3.4% (p(trend) = 0.34). Adjustment for changes in patient and disease characteristics did not substantially alter these results. The rate of IABP use varied substantially by center, from 5.9% to 16.4% (p0.001). Adjustment for patient and disease characteristics resulted in variation from 4.8% to 12.8% across the 10 centers (p0.001). The adjusted rates of preoperative IABP insertion varied from 3.6% to 13.7% (p0.001), and the rates of intra-/postoperative IABP insertion ranged from 1.0% to 5.2% (p0.001). There was no significant correlation between the rates of preoperative and intra-/postoperative IABP use (r(s) = 0.085, p = 0.815).During the 6 years, there was a 47% increase in the rate of IABP utilization. Even after adjustment, there was almost threefold variation in IABP use across centers. This variation likely reflects lack of consensus on the appropriate use of the IABP in CABG patients.

Background The etiology of mitral valvular disease has changed in the last 20 years, and new techniques for the diagnosis and repair of mitral valves have been advanced. A retrospective regional study was conducted to identify changes in patient and disease characteristics and in population-based rates for mitral valve repair and replacement in northern New England. Methods Data from 1648 patients were collected from 5 clinical centers in Maine, New Hampshire, and Vermont between January 1, 1990, and December 31, 1999. U.S. Census data were used to calculate population-based rates. Results Total mitral valve procedures increased 2.4 times, from 8.7 to 20.6 cases/100,000/year (p trend = 0.004). Primary procedures increased from 6.7 to 16.9 cases/100,000/year (p trend = 0.014). Primary mitral valve repair procedures increased 3.7 times, from 2.4 to 8.9 cases/100,000/year (p trend = 0.012), whereas mitral valve replacement increased only 1.9 times, from 4.3 to 8.0 cases/100,000/year (p trend = 0.016). Repeat mitral valve operations did not change significantly (p trend = 0.810). During this period, there was a significant increase of the percentage of octogenarians (p trend = 0.016) and of patients with ejection fractions trend = 0.012). There was a decrease in the percentage of patients with mitral stenosis (p trend = 0.024). Conclusion In an era of a change in the etiology of mitral valvular disease and new techniques for diagnosis and repair of mitral valvular disease, regional data demonstrate substantial increased rates of mitral repair and replacement and expanded indications of older age and poorer left ventricular function.

Background —There is clear evidence that patients having coronary artery bypass graft surgeries with an internal mammary artery (IMA) have better long-term survival. Some studies have suggested a short-term protective effect as well but, because older and sicker patients are less likely to receive an IMA graft, there has been concern that the apparent protective effect of the IMA on short-term mortality has been confounded by other risk factors. This study was intended to examine the independent effect of IMA grafts on in-hospital mortality while adjusting for patient and disease factors. Methods and Results —We studied the use of the left IMA (LIMA) in 21 873 consecutive, isolated, first-time coronary artery bypass graft procedures from 1992 through 1999. A total of 87% of the patients received a LIMA graft. LIMA graft use was associated with a significantly decreased risk of mortality. The crude odds ratio for death (LIMA versus no LIMA) was 0.26 (95% confidence intervals, 0.22, 0.31; P P Conclusions —These data suggest that in addition to its well-documented patency and long-term beneficial effect, LIMA grafting has a strong protective effect on perioperative mortality.

Background . Discontinuing aspirin use in patients before coronary artery bypass grafting (CABG) has focused on bleeding risks. The effect of aspirin use on overall mortality with this procedure has not been studied. Methods . We performed a case patient–control patient study of the 8,641 consecutive isolated CABG procedures performed between July 1987 and May 1991 in Maine, New Hampshire, and Vermont. Patients included all 368 deaths. Each case patient was paired with approximately two matched survivors (control patients). Aspirin use was defined by identification of ingestion within 7 days before the operation. Results . CABG patients using preoperative aspirin were less likely to experience in-hospital mortality in univariate (odds ratio [OR] = 0.73, 95% confidence interval [0.54, 0.97]) and multivariate [OR = 0.55, (0.31, 0.98)] analysis compared to nonusers. No significant difference was seen in the amount of chest tube drainage, transfusion of blood products, or need for reexploration for hemorrhage between patients who did and did not receive aspirin. Conclusions . Preoperative aspirin use appears to be associated with a decreased risk of mortality in CABG patients without significant increase in hemorrhage, blood product requirements, or related morbidities.

We previously reported that transfusion of 1 to 2 units of red blood cells (RBCs) confers a 16% increased hazard of late death after cardiac surgical treatment. We explored whether a similar effect existed among octogenarians.We enrolled 17,026 consecutive adult patients undergoing cardiac operations from 2001 to 2008 in northern New England. Patients receiving more than 2 units of RBCs or undergoing emergency operations were excluded. Early (to 6 months) and late (to 3 years, among those surviving longer than 6 months) survival was confirmed using the Social Security Death Index. We estimated the relationship between RBCs and survival, and any interaction by age (80 years versus ≥80 years) or procedure. We calculated the adjusted hazard ratio (HR), and plotted adjusted survival curves.Patients receiving RBCs had more comorbidities irrespective of age. Patients 80 years of age or older underwent transfusion more often than patients younger than 80 years (51% versus 30%; p0.001). There was no evidence of an interaction by age or procedure (p0.05). Among patients younger than 80 years, RBCs significantly increased a patient's risk of early death [HR, 2.03; 95% confidence interval [CI], 1.47, 2.80] but not late death 1.21 (95%CI, 0.88, 1.67). RBCs did not increase the risk of early [HR, 1.47; 95% CI, 0.84, 2.56] or late (HR, 0.92 95% CI, 0.50, 1.69) death in patients 80 years or older.Octogenarians receive RBCs more often than do younger patients. Although transfusion of 1 to 2 units of RBCs increases the risk of early death in patients younger than 80 years, this effect was not present among octogenarians. There was no significant effect of RBCs in late death in either age group.

Background Cardiac surgery-related acute kidney injury has short- and long-term impact on patients' risk for further morbidity and mortality. Consensus statements have yielded criteria—such as the risk, injury, failure, loss, and end-stage kidney disease (RIFLE) criteria, and the Acute Kidney Injury Network (AKIN) criteria—to define the type and consequence of acute kidney injury. We sought to estimate the ability of both the RIFLE and and AKIN criteria to predict the risk of in-hospital mortality in the setting of cardiac surgery. Methods Data were collected on 25,086 patients undergoing cardiac surgery in Northern New England from January 2001 to December 2007, excluding 339 patients on preoperative dialysis. The AKIN and RIFLE criteria were used to classify patients postoperatively, using the last preoperative and the highest postoperative serum creatinine. We compared the diagnostic properties of both criteria, and calculated the areas under the receiver operating characteristic curve. Results Acute kidney injury occurred in 30% of patients using the AKIN criteria and in 31% of patients using the RIFLE criteria. The areas under the receiver operating characteristic curve for in-hospital mortality estimated by AKIN and RIFLE criteria were 0.79 (95% confidence interval: 0.77 to 0.80) and 0.78 (95% confidence interval: 0.76 to 0.80), respectively ( p = 0.369). Conclusions The AKIN and RIFLE criteria are accurate early predictors of mortality. The high incidence of cardiac surgery postoperative acute kidney injury should prompt the use of either AKIN or RIFLE criteria to identify patients at risk and to stimulate institutional measures that target acute kidney injury as a quality improvement initiative.

Background— Increasing numbers of the very elderly are undergoing aortic valve procedures. We describe the short- and long-term survivorship for this cohort. Methods and Results— We conducted a cohort study of 7584 consecutive patients undergoing open aortic valve surgery without (51.1%; AVR) or with (48.9%; AVR + CABG) concomitant coronary artery bypass graft surgery between November 10, 1987 through June 30, 2006. Patient records were linked to the Social Security Administration’s Death Master File. Survivorship was stratified by age and concomitant CABG surgery. During 39 835 person-years of follow-up, there were 2877 deaths. Among AVR, there were 3304 patients 90 years). Among AVR+CABG patients, there were 2890 patients 90 years). Median survivorship for patients undergoing isolated AVR was 11.5 years (P Conclusions— Survivorship among octogenarians is favorable, with more than half the patients surviving more than 6 years after their surgery. Concomitant CABG surgery does not diminish median survivorship among patients >80 years of age.

Background Increasing numbers of the very elderly are undergoing coronary artery bypass graft surgery (CABG). Short-term results have been studied, but few data are available concerning long-term outcomes. Methods We conducted a cohort study of 54,397 consecutive patients undergoing primary, isolated CABG surgery between July 1, 1987, and June 30, 2006. Patient records were linked to the Social Security Administration's Death Master File. Results During 390,871 person-years of follow-up, there were 17,352 deaths. There were 51,149 patients younger than 80 years, 2,661 patients aged 80 to 84 years, and 587 patients aged 85 or more years who underwent isolated CABG surgery. Crude in-hospital survival was 97.2% for those less than 80 years, 98.3% for those aged 80 to 84 years, and 87.6% for those aged 85 or more years. Patients aged 80 or more years were more likely to be female (46.9%), more likely to be emergency priority (10.2%), and more likely to have associated comorbidities than younger patients. Patients aged 85 or more years were more likely to have intraoperative and postoperative morbid events. Among patients younger than 80, median survival was 14.4 years with an annual incidence of death of 4.2%. Among patients 80 to 84 years old, median survival time was 7.4 years, with an annual incidence rate of death of 10.3%. Among patients aged 85 or more years, median survival was 5.8 years, and the annual incidence of death was 13.7%. Conclusions Although very elderly CABG patients have more comorbidities and more acute presentation than younger patients and their in-hospital mortality rate is high, their long-term survival is surprisingly good.

Background— Renal insufficiency after coronary artery bypass graft (CABG) surgery is associated with increased short-term and long-term mortality. We hypothesized that preoperative patient characteristics could be used to predict the patient-specific risk of developing postoperative renal insufficiency. Methods and Results— Data were prospectively collected on 11 301 patients in northern New England who underwent isolated CABG surgery between 2001 and 2005. Based on National Kidney Foundation definitions, moderate renal insufficiency was defined as a GFR 2 and severe renal insufficiency as a GFR 12 000, prior CABG, congestive heart failure, peripheral vascular disease, diabetes, hypertension, and preoperative intraaortic balloon pump. The predictive model was significant with χ 2 150.8, probability value Conclusions— We developed a robust prediction rule to assist clinicians in identifying patients with normal, or near normal, preoperative renal function who are at high risk of developing severe renal insufficiency. Physicians may be able to take steps to limit this adverse outcome and its associated increase in morbidity and mortality.

Background— Impaired renal function after coronary artery bypass graft (CABG) surgery is a key risk factor for in-hospital mortality. However, perioperative increases in serum creatinine and the association with mortality has not been well-studied. We assessed the hypothesis that perioperative increases in creatinine are associated with increased 90-day mortality. Methods and Results— We studied 1391 patients in northern New England undergoing CABG in 2001 and evaluated preoperative and postoperative creatinine. Patients with preoperative dialysis were excluded. Data were linked to the National Death Index to assess 90-day survival. Kaplan-Meier and log-rank techniques were used. Patients were stratified by percent increase in creatinine from baseline: P Conclusions— Patients with large creatinine increases (≥50%) after CABG surgery have a higher 90-day mortality compared with patients with small increases. Efforts to identify patients with impaired renal function and to preserve renal function before cardiac surgery may yield benefits for patients in the future.

Background— Randomized trials comparing coronary artery bypass graft surgery (CABG) with percutaneous coronary interventions (PCIs) for patients with multivessel coronary disease (MVD) report similar long-term survival for CABG and PCI. These studies used a highly selected population of patients and providers, and their results may not be generalizable to actual care. Our goal in this study was to compare long-term survival of MVD patients treated with CABG vs PCI in contemporary practice. Methods and Results— From our northern New England registries of consecutive coronary revascularizations, we identified 10 198 CABG and 4295 PCI patients with MVD who may have been eligible for either procedure between 1994 and 2001. Vital status was obtained by linkage to the National Death Index. Proportional-hazards regression was used to calculate hazard ratios (HRs) for survival in CABG vs PCI patients after adjustment for comorbidities and disease characteristics. CABG patients were older; had more comorbidities, more 3-vessel disease, and lower ejection fractions; and were more completely revascularized. Adjusted long-term survival for patients with 3-vessel disease was better after CABG than PCI (HR, 0.60; P P =0.77). The survival advantage of CABG for 3-vessel disease patients was present in all patient populations, including women, diabetics, and the elderly and in the era of high stent utilization. Conclusions— In contemporary practice, survival for patients with 3-vessel coronary disease is better after CABG than PCI, an observation that patients and physicians should carefully consider when deciding on a revascularization strategy.

There is limited evidence demonstrating the effectiveness of preoperative intraaortic balloon pump (IABP) use in isolated coronary artery bypass graft (CABG) surgery. A single-center randomized trial demonstrated its benefit. We undertook a multicenter observational study to verify this finding.In 29,950 consecutive patients undergoing isolated CABG between 1995 and 2000 at 10 centers, we compared patients with and without a preoperative IABP. We also compared the effect of preoperative IABP use within 7 high-risk clinical subgroups. To validate the previous randomized trial, patients with any 2 of the following were also analyzed: left main70%, ejection fraction40%, redo CABG, or preoperative intravenous nitroglycerin.Preoperative IABPs were used in 1896 patients (6.3%). These patients had more comorbid conditions and a higher crude mortality than those who did not have preoperative IABPs (9.5% vs 2.3%, P.0001). Preoperative IABP patients were caliper matched to non-preoperative IABP patients using a propensity score. Excess mortality associated with preoperative IABP persisted (9.2% vs 5.8%, P = .0004). In 7 high-risk subgroups, mortality was significantly higher with preoperative IABP. We used propensity caliper matching to compare preoperative IABP with non-preoperative IABP patients who met trial criteria (n = 4332). Preoperative IABP was associated with higher mortality (11.0% vs 6.5%, P = .0009). Removing emergency patients did not alter results.Use of preoperative IABPs was consistently associated with higher mortality. Despite detailed statistical analysis, we were unable to show benefit from preoperative IABP use or confirm the results of a single-center trial that demonstrated its benefit. Assessment of preoperative IABP efficacy will require a randomized trial.

Arteriosclerosis is increasingly viewed as an inflammatory disease. The purpose of these analyses was to examine the preoperative white blood cell (WBC) count, a generalized marker of inflammation, and to assess its association with in-hospital mortality and other adverse outcomes after coronary artery bypass grafting.Information was collected prospectively on 11,270 consecutive patients who had isolated coronary artery bypass grafting in northern New England from 1996 through 2000. Patients were divided into five categories based on their preoperative WBC count. Crude and adjusted in-hospital mortality rates and adverse event rates were calculated using logistic regression.Increasing WBC count across its entire range was associated with a linear increase in the mortality rate. This finding was highly significant (p [trend]0.001) and persisted after adjustment for patient and disease characteristics. Patients with preoperative WBC of at least 12.0 x 10(9)/L had an adjusted mortality rate 2.8 times higher than those with a WBC less than 6.0 x 10(9)/L (4.8% versus 1.7%). An increasing preoperative WBC count was also significantly associated with increasing rates of perioperative strokes and the need for an intraaortic balloon pump but was not associated with mediastinitis.The preoperative WBC count across its entire observed range is a statistically significant independent predictor of in-hospital death and other adverse outcomes after coronary artery bypass grafting. Although the cause of the association between increased WBC count and increased morbidity and mortality is unknown, the preoperative WBC count, which is objectively measured, inexpensive, and always available, can serve as a useful marker to help predict risk before coronary artery bypass grafting.

Background— Replacement of the ascending aorta (Asc Ao) at the time of aortic valve replacement (AVR) is controversial because the risk of progressive dilatation following valve replacement is uncertain. Our aim was to determine the natural history of ascending aortic dilatation following AVR. Methods and Results— We studied 185 patients undergoing AVR at our institution between 1992 and 1999. Clinical and echocardiographic data were obtained by merging our institutional echocardiographic database with the DHMC component of the Northern New England Cardiovascular Disease Study Group database. Baseline Asc Ao measurements obtained from intraoperative transesophageal echocardiograms or early (0.3 cm, occurred in 27/185 patients (15%). Baseline Asc Ao dilatation (≥3.5 cm) was present in 107/185 patients (58%). In this subset of patients, there was no increase in mean Asc Ao diameter (4.0±0.4 versus 3.9±0.6 cm, p=NS) and progressive aortic dilatation occurred in only 10 patients (9.3%). No patients with baseline aortic dilatation (range, 3.5 to 5.3 cm) dilated beyond 5.5 cm on follow-up (range, 2.4 to 5.5 cm). There were no clinical or valvular characteristics that predicted progressive Asc Ao dilatation. Conclusions— An increase in Asc Ao dilatation occurs infrequently following AVR and therefore, argues against routine Asc Ao replacement at the time of AVR.

Heart failure is the most common cause of death among coronary artery bypass graft (CABG) patients. In addition, most variation in observed mortality rates for CABG surgery is explained by fatal heart failure. The purpose of this study was to develop a clinical risk assessment tool so that clinicians can rapidly and easily assess the risk of fatal heart failure while caring for individual patients. Using prospective data for 8,641 CABG patients, we used logistic regression analysis to predict the risk of fatal heart failure. In multivariate analysis, female sex, prior CABG surgery, ejection fraction40%, urgent or emergency surgery, advanced age (70-79 yr and80 yr), peripheral vascular disease, diabetes, dialysis-dependent renal failure and three-vessel coronary disease were significant predictors of fatal postoperative heart failure. A clinical risk assessment tool was developed from this logistic regression model, which had good discriminating characteristics (receiver operating characteristic clinical source = 0.75, 95% confidence interval: 0.71, 0.78).In contrast to previous cardiac surgical scoring systems that predicted total mortality, we developed a clinical risk assessment tool that evaluates risk of fatal heart failure. This distinction is relevant for quality improvement initiatives, because most of the variation in CABG mortality rates is explained by postoperative heart failure.

This study assessed the contribution of angiotensin II, oxygen-free radicals, and vasopressin to the mortality of acute mesenteric ischemia in rats. Rats received saline replacement (16 ml/kg/hr) for 3 hr during and after 85 min of superior mesenteric artery (SMA) occlusion. Only 21% of rats that received saline alone (n = 14, control) survived 48 hr, significantly less than the 100% survival of sham-operated rats (no SMA occlusion, n = 5, P less than 0.01). Neither teprotide (an angiotensin converting-enzyme inhibitor), allopurinol (to reduce oxygen-free radical formation), nor a specific vasopressin antagonist [1-(beta-mercapto-beta,beta-cyclopentamethyleneproprionic acid), 2-(O-methyl) tyrosine arginine-vasopressin] improved 48-hr survival, which was 17% in each group (n = 6, each). Survival improved significantly to 86% (n = 7, P less than 0.001) when intravenous glucagon (1.6 micrograms/kg/min) was given for 2 hr after SMA reperfusion. Survival after dopamine infusion (12 micrograms/kg/min iv) was 67% at 48 hr, a nearly significant improvement (n = 9, P less than 0.06). These results suggest that angiotensin II, oxygen-free radicals, and vasopressin do not contribute significantly to the high mortality observed after acute intestinal ischemia in this rat model, but that glucagon, and to a lesser extent, dopamine, are potentially therapeutic.

• We reviewed the clinical course of 23 patients who received 24 intra-arterial infusions of either streptokinase or urokinase to treat 14 arteries and ten arterial grafts that were occluded due to primary thrombosis (22) or artery-artery embolism (two). Time from symptom onset to treatment was one to 28 days (mean, 11 days). Five infusions (21%) were completely successful since symptoms were eliminated without subsequent operation. Seven infusions (29%) were partially successful since thrombolysis aided, limited, or postponed subsequent surgery. Six infusions (25%) were failures since thrombolysis or clinical improvement did not occur and surgery was required. Six infusions (25%) were associated with thrombolytic complications that required urgent operation (less severe complications occurred in an additional 17% of cases [4/24]). Of the 19 patients without complete success after thrombolytic therapy, 16 underwent surgery during the same admission, two were not operable due to distal disease, and one declined operation. Of the 16 operations, 15 (94%) were successful in restoring graft or artery patency and achieving limb salvage, whereas one failed. In the 12 patients with failure or major complications of thrombolytic treatment, all had successful surgical outcome without morbidity. The actual mean cost of thrombolytic treatment was $8200 per patient and was comparable with the actual mean cost of subsequent surgical treatment in the 16 patients who required operation ($8900 per patient). The effective cost of thrombolytic and surgical treatment was calculated by dividing the actual costs by the proportion of successful cases. The effective cost of thrombolytic therapy per complete success was $39 200 and per complete or partial success was $16 500. This was significantly more than the effective cost of $9400 per complete success of surgical therapy. ( Arch Surg 1988;123:1218-1223)