The 30-Year Influence of a Regional Consortium on Quality Improvement in Cardiac Surgery.

BACKGROUND: The Northern New England Cardiovascular Disease Study Group (NNECDSG) was founded in 1987 as a regional consortium to improve cardiovascular quality in Maine, New Hampshire, and Vermont. We sought to assess the longitudinal impact of the NNECDSG on quality and cost of coronary artery bypass grafting (CABG) during the past 30 years. METHODS: Patients undergoing isolated CABG at 5 medical centers from 1987-2017 were retrospectively reviewed (n = 67,942). They were divided into 4 time periods: 1987-1999 (n = 36,885), 2000-2005 (n = 14,606), 2006-2011(n = 8470), and 2012-2017 (n = 7981). The first period was the time the NNECDSG initiated a series of quality improvement initiatives including data feedback, quality improvement training, process mapping, and site visits. RESULTS: Throughout the 4 time intervals, there was a consistent decline in in-hospital mortality, from 3.4% to 1.8% despite an increase in predicted risk of mortality (P < .001), and a significant decline in in-hospital morbidity, including return to the operating room for bleeding, acute kidney injury, mediastinitis, and low output failure (P < .001). Median length of stay decreased from 7 to 5 days (P < .001), which translated into potential savings of $82,722,023. There was a decrease in use of red blood cells from 3.1 units to 2.6 units per patient in the most current time, which translated into potential savings of $1,985,456. CONCLUSIONS: By using collaborative quality improvement initiatives, the NNECDSG has succeeded in significant, sustained improvements in quality and cost for CABG during the past 30 years. These data support the utility of a regional consortium in improving quality.

Accepted but Unacceptable: Peripheral IV Catheter Failure.

Peripheral intravenous (IV) catheter insertion, the most common invasive hospital procedure performed worldwide, is associated with a variety of complications and an unacceptably high overall failure rate of 35% to 50% in even the best of hands. Catheter failure is costly to patients, caregivers, and the health care system. Although advances have been made, analysis of the mechanisms underlying the persistent high rate of peripheral IV failure reveals opportunities for improvement.

Surgical Atrial Fibrillation Ablation Improves Long-Term Survival: A Multicenter Analysis.

BACKGROUND: The Society of Thoracic Surgeons guidelines recommend surgical ablation (SA) at the time of concomitant mitral operations, aortic valve replacement, coronary artery bypass grafting (CABG), and aortic valve replacement plus CABG for patients in atrial fibrillation (AF). The goal of this analysis was to assess the influence of SA on long-term survival. METHODS: A retrospective analysis of 20,407 consecutive CABG or valve procedures from 2008 to 2015 among seven centers reporting to a prospectively maintained clinical registry was conducted. Patients undergoing operation with documented preoperative AF were included (n = 2,740). Patients receiving SA were compared with patients receiving no SA. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity and mortality. RESULTS: The frequency of SA was 23.1% (n = 634), and an increase was seen in the rate of SA over the study period (p < 0.001). Concomitant SA was performed in 16.2% of CABG, 30.6% of valve, and 24.3% of valve plus CABG procedures. A substantial improvement was found in unadjusted survival among patients undergoing SA (hazard ratio 0.54, 95% confidence interval: 0.42 to 0.70). Moreover, no differences were found in postoperative complications. SA did have longer bypass times (p < 0.001) but a shorter overall length of stay (p < 0.001). After risk adjustment, SA patients had an improved 5-year survival (hazard ratio 0.69, 95% confidence interval: 0.51 to 0.92), and the effect was observed across all operations. CONCLUSIONS: In a multicenter cohort of patients with AF, concomitant SA resulted in substantially improved long-term survival across patients who underwent CABG, valve, and valve plus CABG. These findings support current guidelines from The Society of Thoracic Surgeons that recommend broader application of concomitant SA.

Intensity of Glycemic Control Affects Long-Term Survival After Coronary Artery Bypass Graft Surgery.

BACKGROUND: A patient's hemoglobin (Hb) A1c level, regardless of diabetic status, is a measure of glycemic control. Studies have found it is an independent predictor of short-term death in patients undergoing coronary artery bypass grafting (CABG). In this study, we used preoperative HbA1c to assess whether levels are associated with short-term and long-term survival after CABG. METHODS: From a regional registry of consecutive cases, we identified 6,415 patients undergoing on-pump isolated CABG from 2008 to 2015 with documented preoperative HbA1c level. We defined four HbA1c groups: less than 5.7% (n = 1,713), 5.7% to 6.4% (n = 2,505), 6.5% to 8.0% (n = 1,377), and more than 8% (n = 820). Relationship to in-hospital outcomes and long-term survival was assessed. Outcome rates and hazard ratios were adjusted for patient and disease risk factors using multivariable logistic regression and Cox models. RESULTS: The study included 3,740 patients (58%) not diagnosed as having diabetes and 2,674 with diabetes. Prediabetes (HbA1c 5.7% to 6.4%) was documented in 52% (n = 1,933) of nondiabetic patients. Higher HbA1c values were associated with younger age, female sex, greater body mass index, more comorbid diseases, lower ejection fraction, more 3-vessel coronary disease, and recent myocardial infarction (p < 0.05 trend for all). After adjustment for patient risk, greater HbA1c values were not associated with higher rates of in-hospital death or morbidity. Long-term survival was significantly worse as HbA1c increased. Risk of death increased by 13% for every unit increase in HbA1c (adjusted hazard ratio, 1.13; 95% confidence interval, 1.07 to 1.19; p < 0.001). CONCLUSIONS: Preadmission glycemic control, as assessed by HbA1c, is predictive of long-term survival, with higher levels associated with poorer prognosis. Whether this risk can be modified by better glycemic control postoperatively remains to be determined.

Coronary Revascularization With Single Versus Bilateral Mammary Arteries: Is It Time to Change?

BACKGROUND: Arterial conduits are preferred to venous conduits for coronary artery bypass grafting because of longer patency. A single internal mammary artery (SIMA) is used routinely. Bilateral internal mammary arteries (BIMA) are used less frequently. We sought to determine whether BIMA were superior to SIMA. METHODS: From our regional registry of consecutive open heart operations, we identified 47,984 patients who underwent isolated coronary artery bypass grafting from 1992 to 2014. Of the 1,482 BIMA patients, 1,297 were propensity matched to a cohort of SIMA patients. Short-term outcomes were compared using standard statistical techniques. Long-term survival was compared using Kaplan-Meier estimators and compared using a log-rank test. RESULTS: BIMA patients were younger and had fewer comorbid conditions than SIMA patients. After propensity weighting, BIMA and SIMA patients were well matched. There was no difference in in-hospital outcomes for BIMA versus SIMA patients for mortality (1.2% [n = 15] vs 0.8% [n = 10], p = 0.315), stroke (0.7% [n = 9] vs 0.7% [n = 9), p = 1.000), bleeding (2.2% [n = 28] vs 2.8% [n = 36], p = 0.311), or mediastinitis (0.8% [n = 10] vs 0.9% [n = 12], p = 0.667). The median follow-up was 12 years. Survival was better for BIMA than SIMA (adjusted hazard ratio, 0.79; 95% confidence interval, 0.69 to 0.91; p < 0.001). Survival curves began to separate after 5 years. At 15 years, the absolute difference in survival was 8.4%. CONCLUSIONS: In a large regional experience, BIMA is associated with no upfront risk of adverse events and improved long-term survival compared with SIMA. Our results indicate that BIMA conduits should be considered more frequently during coronary artery bypass grafting due to their demonstrated survival advantage.

Should Diabetes Be a Contraindication to Bilateral Internal Mammary Artery Grafting?

BACKGROUND: This study evaluates the influence of bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) grafting on postoperative morbidity and long-term survival among diabetic patients undergoing coronary artery bypass grafting (CABG). METHODS: A multicenter, retrospective analysis of 47,984 consecutive CABGs performed from 1992 to 2014 at 7 medical centers was conducted. Among the study population, 1,482 CABGs with BIMA were identified, and 1,297 BIMA patients were propensity-matched to 1,297 SIMA patients. The study cohort for this analysis, drawn from matched data, included 430 diabetic patients: 217 SIMA and 213 BIMA. The primary endpoint was long-term survival. Secondary endpoints included postoperative morbidity, length of stay, and in-hospital mortality. RESULTS: The median duration of follow-up was 9.3 (range, 4.3 to 13.9) years. Among propensity-matched diabetic patients, there was no significant difference in age, body mass index, or major baseline comorbidities. The groups were also well matched on the number of diseased coronary arteries and number of distal anastomoses performed. There was no difference in the rate of mediastinitis or sternal dehiscence (p = 0.503) or in-hospital mortality (p = 0.758) between groups. Both groups had a similar median length of stay of 5 (range, 4 to 7) days. Diabetic patients who received a BIMA had significantly improved long-term survival when compared with SIMA patients (hazard ratio 0.75 [95% confidence interval 0.57 to 0.98], p = 0.034). CONCLUSIONS: Among diabetics undergoing CABG, use of BIMA grafting does not result in increased in-hospital morbidity or mortality and confers a long-term survival advantage when compared with SIMA grafting. Thus, diabetic patients should be considered for BIMA grafting more frequently.

Does Use of Bilateral Internal Mammary Artery Grafting Reduce Long-Term Risk of Repeat Coronary Revascularization? A Multicenter Analysis.

BACKGROUND: Although previous studies have demonstrated that patients receiving bilateral internal mammary artery (BIMA) conduits during coronary artery bypass grafting have better long-term survival than those receiving a single internal mammary artery (SIMA), data on risk of repeat revascularization are more limited. In this analysis, we compare the timing, frequency, and type of repeat coronary revascularization among patients receiving BIMA and SIMA. METHODS: We conducted a multicenter, retrospective analysis of 47 984 consecutive coronary artery bypass grafting surgeries performed from 1992 to 2014 among 7 medical centers reporting to a prospectively maintained clinical registry. Among the study population, 1482 coronary artery bypass grafting surgeries with BIMA were identified, and 1297 patients receiving BIMA were propensity-matched to 1297 patients receiving SIMA. The primary end point was freedom from repeat coronary revascularization. RESULTS: The median duration of follow-up was 13.2 (IQR, 7.4-17.7) years. Patients were well matched by age, body mass index, major comorbidities, and cardiac function. There was a higher freedom from repeat revascularization among patients receiving BIMA than among patients receiving SIMA (hazard ratio [HR], 0.78 [95% CI, 0.65-0.94]; P=0.009). Among the matched cohort, 19.4% (n=252) of patients receiving SIMA underwent repeat revascularization, whereas this frequency was 15.1% (n=196) among patients receiving BIMA (P=0.004). The majority of repeat revascularization procedures were percutaneous coronary interventions (94.2%), and this did not differ between groups (P=0.274). Groups also did not differ in the ratio of native versus graft vessel percutaneous coronary intervention (P=0.899), or regarding percutaneous coronary intervention target vessels; the most common targets in both groups were the right coronary (P=0.133) and circumflex arteries (P=0.093). In comparison with SIMA, BIMA grafting was associated with a reduction in all-cause mortality at 12 years of follow-up (HR, 0.79 [95% CI, 0.69-0.91]; P=0.001), and there was no difference in in-hospital morbidity. CONCLUSIONS: BIMA grafting was associated with a reduced risk of repeat revascularization and an improvement in long-term survival and should be considered more frequently during coronary artery bypass grafting.

Optimal Timing From Myocardial Infarction to Coronary Artery Bypass Grafting on Hospital Mortality.

BACKGROUND: Whether delaying coronary artery bypass grafting (CABG) after myocardial infarction (MI) is associated with better outcomes or is an unnecessary use of health care resources is unclear. This study investigated the relationship between MI-to-CABG timing on in-hospital death. METHODS: From the Northern New England Cardiovascular Disease Study Group (NNE) Cardiac Surgery Registry we identified 3,060 isolated CABG patients with prior MI from 2008 to 2014. We compared in-hospital death by MI-to-CABG timing of less than 1 day, 1 to 2 days, 3 to 7 days, and 8 to 21 days. We adjusted for patient characteristics using logistic regression. RESULTS: Among patients with prior MI, CABG was performed within 1 day for 99 (3.2%), 1 to 2 days for 369 (12.1%), 3 to 7 days for 1,966 (64.3%), and 8 to 21 days for 626 (20.5%) patients. NNE-predicted mortality was similar for patients operated on within 1 day (1.8%), 1 to 2 days (1.8%), and 3 to 7 days (1.9%), but was higher for 8 to 21 days (2.4%) of MI. Crude in-hospital mortality was higher for those with MI-to-CABG time of less than 1 day (5.1%) compared with 1 to 2 days (1.6%), 3 to 7 days (1.6%), and 8 to 21 days (2.7%, p = 0.044). Adjusted in-hospital mortality remained high for less than 1 day (5.4%; 95% CI, 1.5% to 9.4%), and similar for 1 to 2 days (1.8%; 95% CI, 0.4% to 3.1%), 3 to 7 days (1.7%; 95% CI, 1.1% to 2.3%), and 8 to 21 days (2.3%; 95% CI, 1.2% to 3.3%) between MI and CABG. CONCLUSIONS: Patients operated on 1 to 2 days and 3 to 7 days after MI had a similar mortality rate, suggesting it may be possible to reduce the MI-to-CABG interval for some patients without sacrificing outcomes. Patients operated on within 1 day after MI had a higher mortality rate.

Accepted but unacceptable: peripheral IV catheter failure.

Peripheral intravenous (IV) catheter insertion, the most common invasive hospital procedure performed worldwide, is associated with a variety of complications and an unacceptably high overall failure rate of 35% to 50% in even the best of hands. Catheter failure is costly to patients, caregivers, and the health care system. Although advances have been made, analysis of the mechanisms underlying the persistent high rate of peripheral IV failure reveals opportunities for improvement.

Effect of preoperative pulmonary hypertension on outcomes in patients with severe aortic stenosis following surgical aortic valve replacement.

Pulmonary hypertension (PH) is prevalent in patients with aortic stenosis (AS); however, previous studies have demonstrated inconsistent results regarding the association of PH with adverse outcomes after aortic valve replacement (AVR). The goal of this study was to evaluate the effects of preoperative PH on outcomes after AVR. We performed a regional prospective cohort study using the Northern New England Cardiovascular Disease Study Group database to identify 1,116 consecutive patients from 2005 to 2010 who underwent AVR ± coronary artery bypass grafting for severe AS with a preoperative assessment of pulmonary pressures by right-sided cardiac catheterization. PH was defined as a mean pulmonary artery pressure of ≥25 mm Hg, with severity based on the pulmonary artery systolic pressure-mild, 35 to 44 mm Hg; moderate, 45 to 59 mm Hg; and severe, ≥60 mm Hg. We found that PH was present in 536 patients (48%). Postoperative acute kidney injury, low-output heart failure, and in-hospital mortality increased with worsening severity of PH. In multivariate logistic regression, severe PH was independently associated with postoperative acute kidney injury (adjusted odds ratio 4.1, 95% confidence interval [CI] 1.7 to 10, p = 0.002) and in-hospital mortality (adjusted odds ratio 6.9, 95% CI 2.5 to 19.1, p <0.001). There was a significant association between PH and decreased 5-year survival (adjusted log-rank p value = 0.006), with severe PH being associated with the poorest survival (adjusted hazard ratio 2.4, 95% CI 1.3 to 4.2, p = 0.003). In conclusion, severe PH in patients with severe AS is associated with increased rates of in-hospital adverse events and decreased 5-year survival after AVR.

Using biomarkers to improve the preoperative prediction of death in coronary artery bypass graft patients.

The current risk prediction models for mortality following coronary artery bypass graft (CABG) surgery have been developed on patient and disease characteristics alone. Improvements to these models potentially may be made through the analysis of biomarkers of unmeasured risk. We hypothesize that preoperative biomarkers reflecting myocardial damage, inflammation, and metabolic dysfunction are associated with an increased risk of mortality following CABG surgery and the use of biomarkers associated with these injuries will improve the Northern New England (NNE) CABG mortality risk prediction model. We prospectively followed 1731 isolated CABG patients with preoperative blood collection at eight medical centers in Northern New England for a nested case-control study from 2003-2007. Preoperative blood samples were drawn at the center and then stored at a central facility. Frozen serum was analyzed at a central laboratory on an Elecsys 2010, at the same time for Cardiac Troponin T, N-Terminal pro-Brain Natriuretic Peptide, high sensitivity C-Reactive Protein, and blood glucose. We compared the strength of the prediction model for mortality using multivariable logistic regression, goodness of fit and tested the equality of the receiving operating characteristic curve (ROC) area. There were 33 cases (dead at discharge) and 66 randomly matched controls (alive at discharge).The ROC for the preoperative mortality model was improved from .83 (95% confidence interval: .74-.92) to .87 (95% confidence interval: .80-.94) with biomarkers (p-value for equality of ROC areas .09). The addition of biomarkers to the NNE preoperative risk prediction model did not significantly improve the prediction of mortality over patient and disease characteristics alone. The added measurement of multiple biomarkers outside of preoperative risk factors may be an unnecessary use of health care resources with little added benefit for predicting in-hospital mortality.

Long-term survival and cardiac troponin T elevation in on- and off-pump coronary artery bypass surgery.

INTRODUCTION: The long-term clinical usefulness of conventional coronary artery bypass graft surgery (CCAB) versus off-pump surgery (OPCAB) remains controversial. Long-term survival and elevation in cardiac troponin T (cTnT) concentration following CCAB and OPCAB have not been assessed. We tested the hypothesis that long-term survival rates for CCAB and OPCAB patients were similar when stratified by cTnT concentration. METHODS AND RESULTS: In this prospective cohort, we followed 1511 nonemergency patients with 2- or 3-vessel disease (778 CCAB and 733 OPCAB cases) from a hospital in northern New England to determine if 6-year survival rates for CCAB and OPCAB patients were similar. The patients underwent surgery between 2000 and 2004 by surgeons who used both procedures. Postoperative cTnT elevation was defined as > or =1 ng/mL, the upper quartile of cTnT values. Data were linked to the Social Security Administration Death Master File. Kaplan-Meier analysis and Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI), with adjustments for baseline patient and disease characteristics. Patients were followed for a median of 4.1 years (mean, 4.0 years). Patients were similar with regard to baseline disease characteristics, comorbidities, cardiac history, function, and anatomy. OPCAB was associated with increased rates of postoperative bleeding and with a worse 6-year survival rate compared with CCAB, regardless of cTnT concentration (cTnT <1 ng/mL, P < .013; cTnT > or =1 ng/mL, P = .017). Compared with CCAB patients, the adjusted HR (95% CI) was 1.59 (1.09-2.32) for OPCAB patients with cTnT concentrations <1 ng/mL and 1.93 (1.12-3.31) for OPCAB patients with cTnT concentrations > or =1 ng/mL. CONCLUSION: Survival is better for CCAB patients than for OPCAB patients, regardless of cTnT concentration. This effect is sustained after multivariable adjustment for baseline mortality risk factors.

Neurocognitive outcomes of off-pump versus on-pump coronary artery bypass: a prospective randomized controlled trial.

BACKGROUND: Preliminary reports have documented the safety of off-pump coronary artery bypass graft compared with conventional coronary artery bypass graft surgery. Whereas off-pump coronary artery bypass graft surgery may be associated with improvement in some short-term outcomes, longer-term outcomes and influence on neurocognitive function have not been fully assessed. We examined short-term and intermediate-term neurocognitive and index admission morbidity and mortality after coronary artery bypass surgery performed with and without the use of extracorporeal circulation. METHODS: We prospectively randomly assigned 201 patients undergoing nonemergent isolated coronary artery bypass graft surgery to conventional coronary artery bypass graft surgery (n = 102) or off-pump coronary artery bypass graft surgery (n = 99). The primary end points of the study were neurocognitive function assessed using a 19-test neurocognitive battery at baseline, discharge, and 6 months. Neurocognitive deficit was defined as a 20% or greater reduction from baseline in at least 20% of the tests. Secondary end points included index admission mortality, stroke, low-output cardiac failure, return to the operating room for bleeding, and postoperative troponin release. Risk ratios and 95% confidence intervals were calculated based on intention-to-treat analysis. RESULTS: There was no difference in neurocognitive deficit at discharge (discharge versus preoperative: risk ratio, 0.83; 95% confidence interval, 0.65 to 1.07) or at 6 months (6 months versus preoperative: risk ratio, 0.94; 95% confidence interval, 0.70 to 1.28). There was no significant difference in mortality or morbidity between the two groups. The off-pump coronary artery bypass graft group had fewer patients with troponin release than the conventional coronary artery bypass graft group. CONCLUSIONS: Off-pump coronary artery bypass graft surgery did not result in decreased frequency of neurocognitive deficit. Off-pump coronary artery bypass graft surgery was associated with substantially lower levels of troponin release after surgery.

Cardiac troponin T levels in on- and off-pump coronary artery bypass surgery.

BACKGROUND: Conventional coronary artery bypass graft surgery (CCAB) has been associated with greater myocardial injury than off-pump surgery (OPCAB). However, the extent of myocardial injury following CCAB and OPCAB has not been assessed by priority of surgery or the number of diseased vessels. We tested the hypothesis that the additional myocardial injury associated with CCAB compared with OPCAB is sustained when patients are stratified by priority and 2- or 3-vessel disease. METHODS AND RESULTS: In this prospective cohort, we measured 24-hour postoperative cardiac troponin T (cTnT) following CCAB and OPCAB surgery to determine if OPCAB results in less perioperative myocardial damage by priority (urgent or elective). We studied 1511 patients who underwent heart surgery in one hospital in northern New England between 2000 and 2004. Surgeons used either CCAB (778 patients) of OPCAB (733 patients). Unpaired t tests were used to test the mean difference in cTnT between CCAB and OPCAB subgroups. Mean cTnT levels were significantly higher in the CCAB group (0.94 ng/mL) than the OPCAB group (0.18 ng/mL) with P < .001; this difference was consistent across urgent and elective surgeries, and patients with both 2- and 3-vessel disease. CCAB patients consistently demonstrated higher cTnT levels. Similar results were evident when stratified by patient characteristics and surgeon. CONCLUSIONS: In summary, higher postoperative cTnT levels are associated with CCAB than with OPCAB, regardless of priority, number of diseased vessels, patient characteristics, or surgeon. OPCAB results in less myocardial injury in patients, whether they present with 2- or 3-vessel disease and whether they undergo urgent or elective cardiac surgery.

Intraoperative red blood cell transfusion during coronary artery bypass graft surgery increases the risk of postoperative low-output heart failure.

BACKGROUND: Hemodilutional anemia during cardiopulmonary bypass (CPB) is associated with increased mortality during coronary artery bypass graft (CABG) surgery. The impact of intraoperative red blood cell (RBC) transfusion to treat anemia during surgery is less understood. We examined the relationship between anemia during CPB, RBC transfusion, and risk of low-output heart failure (LOF). METHODS AND RESULTS: Data were collected on 8004 isolated CABG patients in northern New England between 1996 and 2004. Patients were excluded if they experienced postoperative bleeding or received > or = 3 units of transfused RBCs. LOF was defined as need for intraoperative or postoperative intra-aortic balloon pump, return to CPB, or > or = 2 inotropes at 48 hours. Having a lower nadir HCT was also associated with an increased risk of developing LOF (adjusted odds ratio, 0.90; 95% CI, 0.82 to 0.92; P=0.016), and that risk was further increased when patients received RBC transfusion. When adjusted for nadir hematocrit, exposure to RBC transfusion was a significant, independent predictor of LOF (adjusted odds ratio, 1.27; 95% CI, 1.00 to 1.61; P=0.047). CONCLUSIONS: In this study, we observed that exposure to both hemodilutional anemia and RBC transfusion during surgery are associated with increased risk of LOF, defined as placement of an intraoperative or postoperative intra-aortic balloon pump, return to CPB after initial separation, or treatment with > or = 2 inotropes at 48 hours postoperatively, after CABG. The risk of LOF is greater among patients exposed to intraoperative RBCs versus anemia alone.

The preoperative intraaortic balloon pump in coronary bypass surgery: a lack of evidence of effectiveness.

BACKGROUND: 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. METHODS: 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 main > 70%, ejection fraction < 40%, redo CABG, or preoperative intravenous nitroglycerin. RESULTS: 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. CONCLUSIONS: 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.

A multicenter comparison of intraaortic balloon pump utilization in isolated coronary artery bypass graft surgery.

BACKGROUND: 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. METHODS: 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). RESULTS: 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% (p < 0.001). Adjustment for patient and disease characteristics resulted in variation from 4.8% to 12.8% across the 10 centers (p < 0.001). The adjusted rates of preoperative IABP insertion varied from 3.6% to 13.7% (p < 0.001), and the rates of intra-/postoperative IABP insertion ranged from 1.0% to 5.2% (p < 0.001). There was no significant correlation between the rates of preoperative and intra-/postoperative IABP use (r(s) = 0.085, p = 0.815). CONCLUSIONS: 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.

Preoperative white blood cell count and mortality and morbidity after coronary artery bypass grafting.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Thyroid hormone and cardiac surgery.

Thyroid hormone has important effects on the heart and peripheral vascular system. The relationship between thyroid disease states and cardiovascular hemodynamics is well recognized. Diverse clinical situations are associated with low serum triiodothyronine (T3) levels including a number of cardiovascular illnesses. In particular, cardiopulmonary bypass and open heart operations result in a low T3 state and are often complicated by significant cardiovascular dysfunction similar to that observed in clinical hypothyroidism. Multiple lines of evidence have suggested that T3 can act acutely as a positive inotrope and vasodilator agent. This recognition has prompted a number of investigators to study the effects of T3 administration to patients in the perioperative period. This paper reviews the experimental background that supported such clinical trials as well as outlines the results that have been documented in both adult and pediatric patients undergoing cardiac surgery. Low serum T3 levels resulting from cardiopulmonary bypass can be safely reversed with pharmacologic T3 supplementation. Data have suggested that T3 repletion may improve postoperative hemodynamic performance and lower the incidence of arrythmias. However, beneficial effects on major clinical outcome variables have not yet been conclusively demonstrated, and require future large-scale clinical trials.