Clinical correlates of the initial and long-term cost of coronary bypass surgery and coronary angioplasty.

BACKGROUND: Medical costs vary substantially among patients. Understanding the baseline factors that predict subsequent cost may allow better selection of therapy for individual patients. Understanding the postprocedure events that increase cost should help to improve efficiency and effectiveness of coronary revascularization. METHODS: Data on 4-year costs were collected from patients randomly assigned to coronary angioplasty or bypass surgery as part of the BARI (Bypass Angioplasty Revascularization Investigation) trial. Regression models first examined factors known at the time of randomization that prospectively predicted initial procedure cost and long-term cost. Subsequent models tested the value of postrandomization events as explanatory variables for cost. RESULTS: The independent baseline predictors of higher initial percutaneous transluminal coronary angioplasty cost included 3-vessel disease (+12%) and acute presentations (+22%), whereas the independent predictors of higher initial coronary artery bypass grafting cost included the number of comorbid conditions (+5% per condition) and female sex (+7%). The independent baseline predictors of 4-year cost included heart failure (+26%), diabetes (+22%), comorbidity (+10%), and angioplasty assignment in patients with 2-vessel disease (-15%). Postrandomization models showed higher initial and long-term costs were strongly correlated with the number of repeat revascularization procedures (+30% to +128%) and the occurrence of clinical complications (+8% to +131%). CONCLUSIONS: Two-vessel disease identifies patients likely to have lower costs after angioplasty, whereas heart failure, comorbid conditions, and diabetes identify patients likely to accrue higher costs after either angioplasty or bypass surgery. Long-term costs can be potentially reduced by interventions that decrease procedural complications or reduce the need for repeat revascularization.

A clinical trial of a chest-pain observation unit for patients with unstable angina. Chest Pain Evaluation in the Emergency Room (CHEER) Investigators.

BACKGROUND: Nearly half of patients hospitalized with unstable angina eventually receive a non-cardiac-related diagnosis, yet 5 percent of patients with myocardial infarction are inappropriately discharged from the emergency department. We evaluated the safety, efficacy, and cost of admission to a chest-pain observation unit (CPU) located in the emergency department for such patients. METHODS: We performed a community-based, prospective, randomized trial of the safety, efficacy, and cost of admission to a CPU as compared with those of regular hospital admission for patients with unstable angina who were considered to be at intermediate risk for cardiovascular events in the short term. A total of 424 eligible patients were randomly assigned to routine hospital admission (a monitored bed under the care of the cardiology service) or admission to the CPU (where patients were cared for according to a strict protocol including aspirin, heparin, continuous ST-segment monitoring, determination of creatine kinase isoenzyme levels, six hours of observation, and a study of cardiac function). The CPU was managed by the emergency department staff. Patients whose test results were negative were discharged, and the others were hospitalized. Primary outcomes (nonfatal myocardial infarction, death, acute congestive heart failure, stroke, or out-of-hospital cardiac arrest) and use of resources were compared between the two groups. RESULTS: The 212 patients in the hospital-admission group had 15 primary events (13 myocardial infarctions and 2 cases of congestive heart failure), and the 212 patients in the CPU group had 7 events (5 myocardial infarctions, 1 death from cardiovascular causes, and 1 case of congestive heart failure). There was no significant difference in the rate of cardiac events between the two groups (odds ratio for the CPU group as compared with the hospital-admission group, 0.50; 95 percent confidence interval, 0.20 to 1.24). No primary events occurred among the 97 patients who were assigned to the CPU and discharged. Resource use during the first six months was greater among patients assigned to hospital admission than among those assigned to the CPU (P<0.01 by the rank-sum test). CONCLUSIONS: A CPU located in the emergency department can be a safe, effective, and cost-saving means of ensuring that patients with unstable angina who are considered to be at intermediate risk of cardiovascular events receive appropriate care.

A simplified, practical approach to assessment of severity of mitral regurgitation by Doppler color flow imaging with proximal convergence: validation with concomitant cardiac catheterization.

OBJECTIVE: To compare the proximal convergence method for quantification of mitral regurgitation with findings on concomitant left ventriculography. MATERIAL AND METHODS: In 41 patients (22 men and 19 women, 63 +/- 13 years of age), mitral regurgitation was evaluated concomitantly by Doppler color flow jet area, proximal convergence method, and left ventriculography. A simplified measurement of the proximal convergence, consisting of the aliasing radius and velocity of the proximal isosurface (r2 x V), was used. RESULTS: Angiographic grade correlated well with the proximal convergence method (r2 x V) but had poor correlation with the Doppler color flow jet area method. All patients with a proximal convergence flow rate of less than 10 cm3/s had grade 1 or 2 mitral regurgitation, whereas patients with a proximal convergence flow rate of more than 20 cm3/s had grade 3 or 4 mitral regurgitation. The severity of mitral regurgitation was indeterminate in patients with proximal convergence flow rates from 10 to 20 cm3/s. CONCLUSION: Doppler color flow jet area correlates poorly with angiographic grade of mitral regurgitation. A simplified proximal convergence method is useful for separating grade 3 and 4 from grade 1 and 2 mitral regurgitation in most patients. A group of patients with indeterminate severity of mitral regurgitation remains, however, in whom further assessment is necessary.

Echocardiographic assessment of commissural calcium: a simple predictor of outcome after percutaneous mitral balloon valvotomy.

OBJECTIVES: This study was undertaken to determine whether the presence of calcium in the mitral valve commissures, as demonstrated echocardiographically, could predict outcome and to compare this with an established echocardiographic scoring system. BACKGROUND: Percutaneous mitral balloon valvotomy is an effective form of treatment for mitral valve stenosis. It is important to identify patients who would benefit from this procedure. Commissural splitting is the dominant mechanism by which mitral valve stenosis is relieved by this technique, and thus commissural morphology may predict outcome. METHODS: One hundred forty-nine consecutive patients who underwent percutaneous mitral balloon valvotomy at the Mayo Clinic were evaluated retrospectively. The morphology of the mitral valve apparatus on the baseline echocardiograms was scored in blinded manner using a semiquantitative grading system of leaflet thickening, mobility, calcification and subvalvular thickening (Abascal score). Additionally, each of the medial and lateral commissures was graded for the presence or absence of calcification. End points were death, New York Heart Association functional class, repeat percutaneous mitral balloon valvotomy and mitral valve replacement at follow-up. RESULTS: The mean follow-up period was 1.8 years (maximum 7.9 years). Univariate predictors of death and all events combined included age, the use of a double-balloon technique, the presence of calcium in a commissure and the Abascal score, as continuous variables. Patients with an Abascal score < or = 8 showed a trend toward improved survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (78 +/- 6% vs. 67 +/- 8%, p = 0.07) and free of all events combined (75 +/- 6% vs. 64 +/- 8%, p = 0.07) versus those patients with a score > 8. However, survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (86 +/- 4% vs. 40 +/- 4%) and free of all events combined (82 +/- 5% vs. 38 +/- 10%) at follow-up was significantly different between patients without commissural calcium and those with commissural calcium (p < 0.001). In a Cox regression model with Abascal score and commissural calcium and their interaction, calcification emerged as the only significant variable (p < 0.01). CONCLUSIONS: The presence of commissural calcium is a strong predictor of outcome after percutaneous mitral balloon valvotomy. Patients with evidence of calcium in a commissure have a lower survival rate and a higher incidence of mitral valve replacement and all end points combined. Thus, the simple presence or absence of commissural calcification assessed by two-dimensional echocardiography can be used to predict outcome.

Cost comparison of immediate angioplasty versus thrombolysis followed by conservative therapy for acute myocardial infarction: a randomized prospective trial. Mayo Coronary Care Unit and Catheterization Laboratory Groups.

OBJECTIVE: Immediate angioplasty and thrombolysis followed by conservative therapy are treatment strategies for acute myocardial infarction. The objective of this study was to compare the costs of these two strategies during a 12-month period. METHODS: Of 103 patients with acute myocardial infarction who sought medical assistance within 12 hours after onset of symptoms, 4 were excluded from analysis for various reasons, 51 received tissue plasminogen activator, and 48 underwent immediate angioplasty as the initial revascularization strategy. The main outcome determinants were direct monetary costs and indirect measures of costs, including duration of hospital stay and return to work. RESULTS: No significant difference in monetary costs between the two initial treatment strategies could be demonstrated. A trend was noted toward a briefer hospital stay and fewer late in-hospital procedures for patients treated initially with immediate angioplasty. Other measures of indirect costs were not statistically different. CONCLUSION: The hypothesis that thrombolysis followed by conservative therapy would be more cost-effective than immediate angioplasty in the treatment of patients with acute myocardial infarction could not be substantiated. The two strategies seem to have similar cost-effectiveness.

Immediate angioplasty compared with the administration of a thrombolytic agent followed by conservative treatment for myocardial infarction. The Mayo Coronary Care Unit and Catheterization Laboratory Groups.

BACKGROUND: Immediate angioplasty and the administration of a thrombolytic agent followed by conservative treatment are two approaches to the management of acute myocardial infarction, but these methods have not been compared prospectively. METHODS: We enrolled 108 patients with acute myocardial infarction in a randomized trial designed to test the hypothesis that immediate angioplasty (without previous thrombolytic therapy) may result in greater myocardial salvage than the administration of a thrombolytic agent followed by conservative treatment. The primary end point was the change in the size of the perfusion defect as assessed at admission and discharge by tomographic imaging with technetium-99m sestamibi, a myocardial perfusion agent that can measure myocardium at risk and final infarct size. RESULTS: End-point data were available for 56 patients randomly assigned to receive tissue plasminogen activator (mean [+/- SD] time to start of infusion, 232 +/- 174 minutes after the onset of chest pain) and 47 patients randomly assigned to receive angioplasty (first balloon inflation at 277 +/- 144 minutes). In the case of anterior infarction, myocardial salvage as assessed by imaging with technetium-99m sestamibi was 27 +/- 21 percent of the left ventricle for 22 patients in the thrombolysis group, as compared with 31 +/- 21 percent for 15 patients in the angioplasty group. For infarcts in all other locations, myocardial salvage was 7 +/- 13 percent for 34 patients in the thrombolysis group and 5 +/- 10 percent for 32 patients in the angioplasty group. After adjustment for infarct location, the difference in mean salvage between groups was 0 (P = 0.98), with a 95 percent confidence interval of +/- 6 percent of the left ventricle. CONCLUSIONS: In patients with acute myocardial infarction, immediate angioplasty does not appear to result in greater myocardial salvage than the administration of a thrombolytic agent followed by conservative treatment, although a small difference between these two therapeutic approaches cannot be excluded.

Use of Doppler techniques (continuous-wave, pulsed-wave, and color flow imaging) in the noninvasive hemodynamic assessment of congenital heart disease.

Doppler echocardiography is a relatively new technique that has become an integral part of the cardiovascular ultrasound examination. The hemodynamic information provided by the Doppler technique is complementary to the tomographic anatomy depicted by the two-dimensional examination and, in some patients, may obviate the need for cardiac catheterization. In this article, we focus on the role of Doppler echocardiography in the noninvasive diagnosis of congenital cardiac abnormalities.

Continuous-wave Doppler echocardiographic assessment of severity of calcific aortic stenosis: a simultaneous Doppler-catheter correlative study in 100 adult patients.

Studies of the correlation of aortic valve gradient determined by continuous-wave Doppler echocardiography and that determined at catheterization have, to date, involved young patients and nonsimultaneous measurements. We therefore obtained simultaneous Doppler echocardiographic and catheter measurements of pressure gradient in 100 consecutive adults (mean age 69, range 50 to 89 years). In 63 patients pressure measurements were obtained with dual-catheter techniques and in 37 they were obtained by withdrawal of the catheter from the left ventricle to the ascending aorta. Forty-six of these patients also underwent an outpatient Doppler study 7 days or less before catheterization. The simultaneous pressure waveforms and Doppler spectral velocity profiles were digitized at 10 msec intervals and maximum, mean, and instantaneous gradients (mm Hg) were derived for each. The correlation between the Doppler-determined gradient and the simultaneously measured maximum catheter gradient was r = .92 (SEE = 15 mm Hg), that between the Doppler-determined and mean catheter gradient was r = .93 (SEE = 10 mm Hg), and that between the Doppler and peak-to-peak catheter gradient was r = .91 (SEE = 14). The correlation between the nonsimultaneously Doppler-determined gradient and the maximum gradient measured by catheter was not as strong (r = .79, SEE = 24). The continuous-wave Doppler echocardiographic velocity profile represents the instantaneous transaortic pressure gradient throughout the cardiac cycle. The best correlation with continuous-wave Doppler-determined gradient was obtained with maximum and mean gradients measured by catheter. Continuous-wave Doppler echocardiography can be used to reliably predict the pressure gradient in adults with calcific aortic stenosis.

Is percutaneous coronary angioplasty less expensive than bypass surgery?

Percutaneous transluminal coronary angioplasty is widely considered to be an acceptable and less expensive alternative to bypass surgery in carefully selected patients. We compared expenditures related to cardiac care for 79 unselected patients undergoing coronary angioplasty with expenditures for 89 unselected patients undergoing elective coronary bypass surgery without a previous attempt at angioplasty. All the patients had single-vessel disease. The mean aggregate one-year monetary outlay was 15 per cent lower in the angioplasty group than in the bypass-surgery group. A major component of the expense of angioplasty was the treatment of restenosis in the 33 per cent of patients in this group in whom this late complication occurred. We conclude that percutaneous transluminal coronary angioplasty has potential for reducing expenditures for cardiac revascularization and that a further reduction may be obtainable when the rates of restenosis are improved.