Improved in-hospital mortality in women undergoing coronary artery bypass grafting. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: Few studies have examined the changes in in-hospital mortality for women over time. We describe the changing case mix and mortality for women undergoing coronary artery bypass grafting (CABG) from 1987 to 1997 in northern New England. METHODS: Data were collected on 8,029 women and 21,139 men undergoing isolated CABG. The study consisted of three time periods (1987 to 1989, 1990 to 1992, and 1993 to 1997) to account for regional efforts to improve quality of care that occurred during 1990 to 1992. RESULTS: Compared with 1987 to 1989, women undergoing CABG in 1993 to 1997 were older, had poorer ventricular function, and more often required urgent or emergency operations. The crude and adjusted mortality rates for both women and men decreased significantly over time. The absolute magnitude of the change in adjusted rates was greater for women (3.1%) than for men (1.5%). Although women represented only 28% of the study population, the decrease in their mortality accounted for 44% of the total decrease in adjusted mortality during the study period. CONCLUSIONS: Over the last decade there has been a marked decrease in CABG mortality for women, despite a worsening case mix.

Geographic variation in the treatment of acute myocardial infarction: the Cooperative Cardiovascular Project.

CONTEXT: Quality indicators for the treatment of acute myocardial infarction include pharmacologic therapy, reperfusion, and smoking cessation advice, but these therapies may not be administered to all patients who could benefit from them. OBJECTIVE: To assess geographic variation in adherence to quality indicators for treatment of acute myocardial infarction. DESIGN: Inception cohort using data from the Health Care Financing Administration Cooperative Cardiovascular Project. SETTING: Acute care hospitals in the United States. PATIENTS: A total of 186800 Medicare beneficiaries hospitalized for treatment of confirmed acute myocardial infarction from February 1994 through July 1995. MAIN OUTCOME MEASURES: Adherence to quality indicators for pharmacologic therapy, reperfusion, and smoking cessation advice for patients judged to be ideal candidates for these therapies. The mean rates of adherence to these quality indicators for the entire United States were determined, and the 20th and 80th percentiles of the age- and sex-adjusted rates for each of 306 hospital referral regions were contrasted (mean rate [20th-80th percentiles]). RESULTS: Aspirin was used frequently both during hospitalization (86.2% [82.6%-90.1%]) and at discharge (77.8% [72.5% -83.9%]). Calcium channel blockers were withheld from most patients with impaired left ventricular function (81.9% [73.6%-90.8%]). Lower rates were seen in the use of angiotensin-converting enzyme inhibitors at discharge (59.3% [49.2%-69.2%]); reperfusion, using thrombolytic therapy or coronary angioplasty (67.2% [59.8%-75.1%]); prescription of beta-blockers at discharge (49.5% [35.8%-61.5%]); and for smoking cessation advice (41.9% [32.8%-51.3%]). CONCLUSIONS: Substantial geographic variation exists in the treatment of patients with acute myocardial infarction, and these gaps between knowledge and practice have important consequences. Therapies with proven benefit for AMI are underused despite strong evidence that their use will result in better patient outcomes.

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.

Sensitivity of prevertebral soft tissue measurement of C3 for detection of cervical spine fractures and dislocations.

A prevertebral soft tissue measurement exceeding 4 to 5 mm at C3 on a lateral spine radiograph is considered to be evidence of cervical spine injury. The objective of this study was to determine the sensitivity of the prevertebral soft tissue measurement at C3 in patients with proven cervical spine fractures or dislocations and to determine if this measurement correlates with the location or mechanism of injury. Consecutive patients 16 years of age or older who were admitted from July 1988 to June 1995 to a tertiary referral hospital with a discharge diagnosis of cervical spine fracture or dislocation were retrospectively studied. Patients were excluded if an interpretable lateral cervical radiograph taken within 24 hours of the injury was unavailable, medical records were unavailable or incomplete, the injury was caused by penetrating trauma or attempted hanging, or retropharyngeal air was present on the lateral radiograph. For each study patient, the earliest available lateral radiograph was obtained, and the prevertebral soft tissue measurement at the inferior aspect of C3 was recorded. All medical records and reports of imaging studies were reviewed. Two hundred thirty-two patients were identified and 21 were excluded, leaving 212 study patients. Injuries were classified as high (C1 to C2), low (C3 to C7), anterior, or posterior. For each patient the mechanism of injury was inferred from the fracture pattern according to established criteria. For all patients the sensitivity of a prevertebral soft tissue measurement at C3 of > 4 mm was 66% (95% confidence interval [CI] 59, 72). For C1 to C2 (n = 71) and C3 to C7 (n = 138) injuries, the sensitivities were 64% (95% CI 56, 78) and 64% (95% CI 56, 72), respectively. For anterior (n = 95) and posterior (n = 70) injuries the sensitivities were 64% (95% CI 54, 74) and 64% (95% CI 52, 75), respectively. There was no statistically significant difference in the prevertebral soft tissue measurement at C3 for high versus low injury, anterior versus posterior injury, or mechanism of injury. These results show that the prevertebral soft tissue measurement at C3 is an insensitive marker of cervical spine fracture or dislocation and does not correlate with the location or mechanism of injury.

A regional intervention to improve the hospital mortality associated with coronary artery bypass graft surgery. The Northern New England Cardiovascular Disease Study Group.

OBJECTIVE: To determine whether an organized intervention including data feedback, training in continuous quality improvement techniques, and site visits to other medical centers could improve the hospital mortality rates associated with coronary artery bypass graft (CABG) surgery. DESIGN: Regional intervention study. Patient demographic and historical data, body surface area, cardiac catheterization results, priority of surgery, comorbidity, and status at hospital discharge were collected on CABG patients in Northern New England between July 1, 1987, and July 31, 1993. SETTING: This study included all 23 cardiothoracic surgeons practicing in Maine, New Hampshire, and Vermont during the study period. PATIENTS: Data were collected on 15,095 consecutive patients undergoing isolated CABG procedures in Maine, New Hampshire and Vermont during the study period. INTERVENTIONS: A three-component intervention aimed at reducing CABG mortality was fielded in 1990 and 1991. The interventions included feedback of outcome data, training in continuous quality improvement techniques, and site visits to other medical centers. MAIN OUTCOME MEASURE: A comparison of the observed and expected hospital mortality rates during the postintervention period. RESULTS: During the postintervention period, we observed the outcomes for 6488 consecutive cases of CABG surgery. There were 74 fewer deaths than would have been expected. This 24% reduction in the hospital mortality rate was statistically significant (P = .001). This reduction in mortality rate was relatively consistent across patient subgroups and was temporally associated with the interventions. CONCLUSION: We conclude that a multi-institutional, regional model for the continuous improvement of surgical care is feasible and effective. This model may have applications in other settings.

The effect of peripheral vascular disease on long-term mortality after coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

OBJECTIVE: To examine the effect of peripheral vascular disease (PVD) on long-term mortality after successful myocardial revascularization. METHODS: We performed a regional cohort study of 2871 consecutive patients discharged alive after coronary artery bypass graft surgery at five tertiary care centers in Maine, New Hampshire, and Vermont between 1987 and 1989. Data reflecting patient characteristics, heart disease severity, and comorbidity were collected prospectively; the presence of clinical and subclinical indicators of PVD was determined by medical record review; and vital status was determined using the National Death Index (mean follow-up, 4.4 years). RESULTS: Five-year mortality following coronary artery bypass graft surgery was substantially higher in the 755 patients with indicators of PVD (20%; 95% confidence interval [CI], 17% to 23%) than in the 2116 patients without PVD (8%, 95% CI, 7 to 9; P<.001). The crude hazard ratio of long-term mortality associated with PVD was 2.77 (95% CI, 2.19 to 3.50; P<.001). After adjusting for their higher comorbidity scores, more advanced cardiac disease, and age, mortality rates in patients with PVD remained twice as high as those in patients without PVD (adjusted hazard ratio, 2.01; 95% CI, 1.57 to 2.58; P<.001). Long-term mortality was increased in patients with any of the indicators of PVD. Patients with multilevel PVD had especially high late mortality rates (adjusted hazard ratio, 2.46; 95% CI, 1.64 to 3.68; P<.001). CONCLUSIONS: Even after successful myocardial revascularization, patients with PVD remain at substantially increased risk for long-term mortality. The presence of clinical or subclinical PVD is important when predicting both short- and long-term outcomes in patients considering coronary artery bypass graft surgery.

The effect of peripheral vascular disease on in-hospital mortality rates with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

PURPOSE: The purpose of this study was to examine the effect of peripheral vascular disease (PVD) on in-hospital mortality rates after coronary artery bypass grafting (CABG). METHODS: We performed a regional cohort study of 3003 patients undergoing CABG between 1987 and 1989 at five tertiary care centers in Maine, New Hampshire, and Vermont. Data reflecting patient characteristics, severity of heart disease, comorbidity, and in-hospital mortality rates were collected prospectively; the presence of clinical and subclinical indicators of PVD was determined retrospectively. RESULTS: Observed in-hospital mortality rates with CABG were 2.4-fold higher in the 796 patients with indicators of PVD (7.7%) than in the 2207 patients without PVD (3.2%) (crude odds ratio [OR] 2.42 [95% confidence interval (CI) 1.73-3.37]). After adjusting for their higher comorbidity scores, more advanced heart disease, and age, patients with PVD remained 73% more likely to die in hospital after CABG (adjusted OR 1.73 [CI 1.19-2.51]). The excess risk of in-hospital death associated with PVD was attributable largely to lower extremity occlusive disease (adjusted OR 2.03 [CI 1.34-3.07]). Subclinical lower extremity occlusive disease (asymptomatic absence of pedal pulses) had the same effect as clinically overt disease. Cerebrovascular disease had a small and statistically nonsignificant effect on CABG-related deaths (adjusted OR 1.13 [CI 0.73-1.74]). Excess mortality rates in patients with PVD were primarily due to increased risk of death from heart failure and dysrhythmias, but not to cerebrovascular accidents or peripheral arterial complications. CONCLUSIONS: The presence of lower extremity arterial occlusive disease is an important, independent predictor of in-hospital mortality rates for patients undergoing CABG. Controlled studies of the long-term effects of CABG in patients with PVD are needed to determine the optimal role of myocardial revascularization in this population.