Failure to improve left ventricular function after coronary revascularization for ischemic cardiomyopathy is not associated with worse outcome.

Background-Preoperative identification of viable myocardium in patients with ischemic cardiomyopathy is considered important because CABG can result in recovery of left ventricular (LV) function. However, the hypothesis that lack of improvement of LV function after CABG is associated with poorer patient outcome is untested. Methods and Results-Outcome was compared in patients with ischemic LV dysfunction (LVEF 0.05 increase in LVEF (group A) and 36 (35%) had no significant change, or

Prognostic value of noninvasive testing one year after orthotopic cardiac transplantation.

OBJECTIVES: We sought to evaluate the prognostic value of routine noninvasive testing--stress thallium-201 imaging, rest two-dimensional echocardiography and rest equilibrium radionuclide angiography--1 year after cardiac transplantation. BACKGROUND: Coronary artery vasculopathy is the most important cause of late death after orthotopic cardiac transplantation. Several clinical variables have been identified as risk factors for development of coronary vasculopathy. Traditional noninvasive diagnostic testing has been shown to be relatively insensitive for identifying patients with angiographic vasculopathy. METHODS: Results of prospectively acquired noninvasive testing in 47 consecutive transplant recipients alive 1 year after transplantation were related to subsequent survival. Other clinical variables previously shown to be associated with the development of coronary artery vasculopathy were also included in the analysis. RESULTS: The 5-year survival rate after cardiac transplantation was 81%. By univariate analysis, echocardiography (chi-square 9.21) and stress thallium-201 myocardial perfusion imaging (chi-square 16.76) were predictive for survival, whereas rest equilibrium radionuclide angiography was not. Clinical contributors to survival were donor age (chi-square 4.56), number of human leukocyte antigen mismatches (chi-square 3.06) and cold ischemic time (chi-square 3.23). By multivariate analysis, stress myocardial imaging remained the only significant predictor of survival (risk ratio 0.27; 95% confidence interval 0.06 to 0.89). CONCLUSIONS: Normal thallium-201 stress myocardial perfusion imaging 1 year after cardiac transplantation is an important predictor of 5-year survival.

Knowledge of blood pressure levels and targets in patients with coronary artery disease in the USA.

Little is known about patient awareness of nationally recommended blood pressure targets, especially among patients with cardiac disease. To examine this issue, we interviewed 738 patients hospitalized with coronary artery disease to assess their knowledge of their systolic and diastolic blood pressure levels as well as corresponding national targets. We used bivariate and multivariate analyses to determine if any patient demographic or clinical characteristics were associated with blood pressure knowledge. Only 66.1% of patients could recall their own systolic and diastolic blood pressure levels. Only 48.9% of all patients could correctly name targets for these values. Knowledge of target blood pressure levels was particularly poor among patients who were female (odds ratio (OR) 0.69; 95% confidence interval (CI) 0.49-0.98), aged > or =60 years (OR 0.70, CI 0.51-0.97), without any college education (OR 0.48, CI 0.35-0.65), without a documented history of hypertension (OR 0.57, CI 0.39-0.84), and with known diabetes (OR 0.46, CI 0.33-0.66). Patients in the highest risk group, according to Joint National Committee guidelines stratification, were no more knowledgeable about their blood pressure levels and targets than lower risk patients. A significant proportion of patients hospitalized with coronary artery disease do not know their own blood pressure levels or targets. Current blood pressure education efforts appear inadequate, particularly for certain patient subgroups in which hypertension is an important modifiable risk factor.

Quantitative analysis of planar technetium-99m-sestamibi myocardial perfusion images using modified background subtraction.

Standard interpolative background subtraction, as used for thallium-201 (201Tl), may create artifacts when applied to planar technetium-99m-Sestamibi (99mTc-Sestamibi) images, apparently because of the oversubtraction of relatively high extra-cardiac activity. A modified background subtraction algorithm was developed and compared to standard background subtraction in 16 patients who had both exercise-delayed 201Tl and exercise-rest 99mTc-Sestamibi imaging. Furthermore, a new normal data base was generated. Normal 99mTc-Sestamibi distribution was slightly different compared to 201Tl. Using standard background subtraction, mean defect reversibility was significantly underestimated by 99mTc-Sestamibi compared to 201Tl (2.8 +/- 4.9 versus -1.8 +/- 8.4, p less than 0.05). Using the modified background subtraction, mean defect reversibility on 201Tl and 99mTc-Sestamibi images was comparable (2.8 +/- 4.9 versus 1.7 +/- 5.2, p = NS). We conclude, that for quantification of 99mTc-Sestamibi images a new normal data base, as well as a modification of the interpolative background subtraction method should be employed to obtain quantitative results comparable to those with 201Tl.

Reproducibility of quantitative planar thallium-201 scintigraphy: quantitative criteria for reversibility of myocardial perfusion defects.

Fifty-two paired stress/delayed planar 201TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of 201TI perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size. Based upon intraobserver variability, objective quantitative criteria for reversibility of perfusion abnormalities were defined. These objective criteria were tested prospectively in a separate group of 35 201TI studies and compared with the subjective interpretation of quantitative circumferential profiles. Overall, exact agreement existed in 78% of images (kappa statistic k = 0.66). We conclude that quantification of planar 201TI scans is highly reproducible, with acceptable inter- and intraobserver variability. Objective criteria for lesion reversibility correlated well with analysis by experienced observers.

Demonstration of reperfusion after thrombolysis with technetium-99m isonitrile myocardial imaging.

Technetium-99m isonitrile myocardial perfusion imaging was employed in a patient undergoing thrombolytic therapy with recombinant tissue plasminogen activator for acute anteroseptal myocardial infarction. Technetium-99m isonitrile does not demonstrate significant myocardial redistribution after intravenous injection. The imaging agent was administered in the emergency room, prior to the initiation of thrombolytic therapy. The initial area at risk for infarction was visualized on images obtained after the patient had been effectively treated. Imaging performed 5 days later, after repeat injection of [99mTc]isonitrile, showed a smaller myocardial perfusion defect indicating salvage of myocardium. Thus, this technique offers promise as a noninvasive means of assessing the area at risk, the success of reperfusion, and the presence of salvaged myocardium, early in the course of acute myocardial infarction.

Quantitative planar thallium-201 stress scintigraphy: a critical evaluation of the method.

The results of quantitative analysis of planar thallium-201 stress scintigraphy are superior to those of visual analysis. The increased sensitivity for detection of coronary artery disease is associated with maintenance of specificity. Consequently, we believe that quantitative analysis is the state-of-the-art for planar 201Tl stress scintigraphy. We emphasize that for reliable and reproducible results, rigorous quality control and strict adherence to a standardized imaging protocol are necessary. An important feature is clarity of display of computer data. In our experience, the most important feature for making quantitative analysis reliable and accessible for a broader user market is simultaneous display of the lower limits of normal with processed patient data. This provides a simple visual impression of the degree and extent of abnormal 201Tl distribution and kinetics relative to the lower limit of normal.

Data feedback efforts in quality improvement: lessons learned from US hospitals.

BACKGROUND: Data feedback is a fundamental component of quality improvement efforts, but previous studies provide mixed results on its effectiveness. This study illustrates the diversity of hospital based efforts at data feedback and highlights successful strategies and common pitfalls in designing and implementing data feedback to support performance improvement. METHODS: Open ended interviews with 45 clinical and administrative staff in eight US hospitals in 2000 concerning their perceptions about the effectiveness of data feedback in supporting performance improvement efforts were analysed. The hospitals were chosen to represent a range of sizes, geographical regions, and beta blocker improvement rates over a 3 year period. Data were organized and analyzed in NUD-IST 4 using the constant comparative method of qualitative data analysis. RESULTS: Although the data feedback efforts at the hospitals were diverse, the interviews suggested that seven key themes may be important: (1) data must be perceived by physicians as valid to motivate change; (2) it takes time to develop the credibility of data within a hospital; (3) the source and timeliness of data are critical to perceived validity; (4) benchmarking improves the meaningfulness of data feedback; (5) physician leaders can enhance the effectiveness of data feedback; (6) data feedback that profiles an individual physician's practices can be effective but may be perceived as punitive; (7) data feedback must persist to sustain improved performance. Embedded in several themes was the view that the effectiveness of data feedback depends not only on the quality and timeliness of the data, but also on the organizational context in which such efforts are implemented. CONCLUSIONS: Data feedback is a complex and textured concept. Data feedback strategies that might be most effective are suggested, as well as potential pitfalls in using data to promote performance improvement.

Trends in costs of percutaneous transluminal coronary angioplasty.

OBJECTIVE: To evaluate recent trends in the cost of percutaneous transluminal coronary angioplasty (PTCA), particularly the impact of newer technology and changing patient profile. STUDY DESIGN: Retrospective study with a 6-month follow up. PATIENTS AND METHODS: We compared the data on two groups of 100 consecutive patients admitted for elective PTCA at Yale-New Haven Hospital in 1995 and 1996. Hospital records, cineangiograms, and hospital cost accounting system were reviewed, and 6-month clinical outcomes were obtained from telephone interviews and medical chart review. RESULTS: Demographic and clinical characteristics did not differ between the 1995 and 1996 groups of patients, nor was a difference detected in in-hospital and 6-month clinical outcomes between 1995 and 1996. Angiographic features of treated lesions were different between the two groups, with a significantly higher frequency of type C and totally occluded lesions in 1996 (p = 0.002 and p = 0.04, respectively). The total hospital costs were higher in 1996 compared with 1995 ($11,799 +/- $6189 vs $10,087 +/- $5608; p = 0.04). This difference persisted after adjustment for changes in patient population. The major factor responsible for escalating costs was a 45% increase in catheterization laboratory costs ($8575 +/- $4524 in 1996 vs $5916 +/- $3030 in 1995; P < 0.0001). In contrast, the noncatheterization costs decreased substantially during this period, largely as a result of an approximately 33% decrease in length of stay (3.75 +/- 2.66 days in 1995 vs 2.57 +/- 1.99 days in 1996; P = 0.0005). In a multiple linear regression model, the most important determinants of cost were lesion characteristics, stent use, and radiographic contrast volume. CONCLUSIONS: Despite cost reduction efforts, the costs of PTCA are rising because of increased consumption of resources in the catheterization laboratory.

Exercise testing with myocardial perfusion imaging in patients with normal baseline electrocardiograms: cost savings with a stepwise diagnostic strategy.

BACKGROUND: It has been suggested that in patients with a normal resting electrocardiogram (ECG), exercise radionuclide myocardial perfusion imaging (MPI) does not add significant incremental diagnostic information to exercise ECG. METHODS AND RESULTS: Of 840 consecutive patients referred for physical exercise MPI, 313 (37%) had normal resting ECGs. There were 189 men and 124 women with a mean age of 54+/-11.9 years. Exercise MPI was performed with either TI-201 or 99mTc-labeled sestamibi. Overall concordance between exercise ECG result and MPI result was 79% (kappa agreement = .54). One hundred eighty-four patients had normal exercise ECG; 181 (98.4%) of these also had normal exercise MPI. In 271 patients with low (< or =20%) to intermediate (21% to 70%) pre-exercise likelihood of coronary artery disease (CAD), concordance between normal exercise ECG and normal MPI was 100%. In the high likelihood (> or =71%) group 3 (15 %) patients with normal exercise ECG had abnormal exercise MPI. Of 129 patients with abnormal exercise ECG, 67 (52%) patients also had abnormal MPI, but 62 (48%) patients had normal MPI. Complete follow-up was obtained in 89% of patients at 9 months. Only 1 hard cardiac event occurred: nonfatal myocardial infarction. Twenty-one (8%) patients had subsequent coronary revascularization or admission with unstable angina. Although both abnormal stress ECG and abnormal exercise MPI were significantly (P < .0001) associated with hard and "soft" events, the association of abnormal exercise MPI was significantly stronger. Because all patients with a low and intermediate likelihood of CAD who had normal exercise ECG also had normal exercise MPI, we propose a stepwise diagnostic testing strategy whereby exercise MPI imaging is performed only in patients with a low to intermediate likelihood of CAD when the exercise ECG is abnormal. When the exercise ECG is performed first, and exercise MPI is performed only when the exercise ECG is abnormal, substantial (38%) cost savings can be achieved. In patients with a high likelihood of CAD, the exercise ECG may be falsely negative, and exercise MPI is preferred. CONCLUSION: In patients with normal resting ECGs a stepwise diagnostic strategy can reduce costs of exercise testing without compromising diagnostic yield when pretest likelihood of coronary artery disease is taken into consideration.

Association of patients' perception of health status and exercise electrocardiogram, myocardial perfusion imaging, and ventricular function measures.

BACKGROUND: Patients' viewpoint of their health status is increasingly used as an important outcome measure of the success of treatments. Because clinicians rarely formally measure patients' health-related quality of life, the question arises whether noninvasive testing for ischemia can provide similar information regarding physical functioning and general health perception. METHODS: We measured physical functioning and general health status with the Medical Outcomes Study Short Form (SF-36) survey in 195 consecutive patients (68% male, mean age 55.6 +/- 11.1 years) referred for exercise testing with myocardial perfusion imaging. The survey was completed immediately before the exercise test. RESULTS: In the multivariate analysis, the strongest predictor of physical functioning and general health perception was metabolic equivalents. However, the best model, including demographic, clinical, and test variables, predicted only 14% of the variation in physical functioning and 10% of the variability in general health perception. CONCLUSIONS: The variation in physical functioning and general health perception, as measured by the SF-36, among patients referred for exercise testing is not predicted well by the results of the test. As expected, several test results are significantly associated with physical functioning and general health perception; however, there was substantial overlap among individual patients, suggesting that the parameters are poor surrogates for the actual assessment of the domains. If these domains are deemed important to tracking patient outcomes, then they should supplement the current assessments of these patients.

A qualitative study of increasing beta-blocker use after myocardial infarction: Why do some hospitals succeed?

CONTEXT: Based on evidence that beta-blockers can reduce mortality in patients with acute myocardial infarction (AMI), many hospitals have initiated performance improvement efforts to increase prescription of beta-blockers at discharge. Determination of the factors associated with such improvements may provide guidance to hospitals that have been less successful in increasing beta-blocker use. OBJECTIVES: To identify factors that may influence the success of improvement efforts to increase beta-blocker use after AMI and to develop a taxonomy for classifying such efforts. DESIGN, SETTING, AND PARTICIPANTS: Qualitative study in which data were gathered from in-depth interviews conducted in March-June 2000 with 45 key physician, nursing, quality management, and administrative participants at 8 US hospitals chosen to represent a range of hospital sizes, geographic regions, and changes in beta-blocker use rates between October 1996 and September 1999. MAIN OUTCOME MEASURES: Initiatives, strategies, and approaches to improve care for patients with AMI. RESULTS: The interviews revealed 6 broad factors that characterized hospital-based improvement efforts: goals of the efforts, administrative support, support among clinicians, design and implementation of improvement initiatives, use of data, and modifying variables. Hospitals with greater improvements in beta-blocker use over time demonstrated 4 characteristics not found in hospitals with less or no improvement: shared goals for improvement, substantial administrative support, strong physician leadership advocating beta-blocker use, and use of credible data feedback. CONCLUSIONS: This study provides a context for understanding efforts to improve care in the hospital setting by describing a taxonomy for classifying and evaluating such efforts. In addition, the study suggests possible elements of successful efforts to increase beta-blocker use for patients with AMI.