Rates Of Coronary Artery Bypass Grafting Research Articles

Myocardial revascularisation in elderly patients with refractory or unstable angina and advanced coronary disease.

Elderly patients with ischaemic heart disease are often treated more conservatively and for longer than younger patients, but this strategy may result in subsequent invasive intervention of more advanced and higher risk coronary disease. We performed a retrospective analysis of 109 patients aged > or = 70 years (mean age 74 years, 66% men), who presented with angina refractory to maximal medical treatment or unstable angina over a 2-year period (1988-1990), to compare the relative risks and benefits of myocardial revascularisation [coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA)] in this higher-risk age group. Sixty patients underwent CABG and 49 patients PTCA. There were eight periprocedural deaths in total (six in the CABG group, and two in the PTCA group, P = 0.29). Six patients in the CABG group suffered a cerebrovascular accident (two fatal). Acute Q-wave myocardial infarction occurred in one patient in the CABG group and in two patients in the PTCA group. The length of hospital stay was longer for the CABG group (CABG group 11.4 +/- 5.4 days, range 7-30 days, PTCA group 7.4 +/- 7.6 days, range 1-39 days, P = 0.01). Outcome was assessed using the major cardiac event rate (MACE; i.e. the rate of death, myocardial infarction, repeat CABG or PTCA). The cumulative event-free survival in the CABG group in 1, 2 and 3 years was 87, 85 and 85%, respectively. In contrast, in the PTCA group it was 55, 48 and 48% (P = 0.0001). Age, sex, number of diseased vessels, degree of revascularisation and left ventricular function were not predictive of the recurrence of angina in both groups. Actuarial survival (total mortality, including perioperative mortality) was lower at 1 year in the CABG group due to the higher perioperative mortality, but similar in both groups after the second year (P = 0.62). Elderly patients with refractory or unstable angina who are revascularised surgically have a better long-term outcome (less frequent event rate of the composite end-point--myocardial infarction, revascularisation procedures and death) compared with those who are revascularised with PTCA. This benefit is been realised after the second year. Total mortality is similar in both groups after the second year. Therefore elderly patients who are fit for surgery should not be denied the benefits of CABG. PTCA may be regarded as a complementary and satisfactory treatment, especially for those whose life expectancy is limited to less than 2 years. The use of stents may improve outcome in the PTCA group and this needs to be evaluated.

Impact of the 1991 NHS reforms on the availability and use of coronary revascularisation in the UK (1987-1995)

To describe changes in the availability, utilisation, and waiting times for coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) between 1987/88 and 1994/95 and to review commissioning of these services. A series of cross sectional surveys and interviews with purchasers and providers. Four health regions in the United Kingdom. All residents aged 25 years or more who underwent coronary revascularisation. There has been little change in the availability of consultants in cardiology in specialist centres, while the number of non-consultant cardiologists has risen significantly. The availability of consultant surgeons more than doubled in some regions, while non-consultant surgical staff increased by 40-90%. The NHS rate of use of both CABG and PTCA has increased steadily since 1987/88. In 1994/95, only two districts had CABG rates of less than 300 per million population. The additional contribution of privately funded cases varied between 14-23% for CABG and 7-30% for PTCA. Regional rates varied 1.3-fold for CABG and threefold for PTCA in 1994/95, while district rates of CABG varied 3.6-fold and PTCA 18-fold. Revascularisation rates were higher in districts with least need in 1991/92 and this persisted over the following three years. The overall waiting time for CABG (214 days) was largely unchanged from 1992/93 (234 days). The overall waiting time for PTCA (138 days) was 25% shorter than in 1992/93 (185 days). Prioritisation of patients waiting over a year had not yet adversely affected the waiting time of more urgent patients. Commissioning has faced a complex web of interconnected problems which, in general, caused more problems for purchasers than providers initially but which appear to be of increasing concern to providers. The 1991 NHS reforms had had no observable impact on the availability and use of coronary revascularisation by 1995. Continued monitoring is necessary to detect any delayed effect.

Setting targets for CABG surgery in the north western region.

A national target for coronary artery bypass graft (CABG) operations of 300 per million population was established by the Department of Health in 1987. Regional Health Authorities were required in 1993-1994 to achieve this target. The 1990-1991 Regional all-ages CABG rate was 239 per million population. The North Western Region planned to devolve the purchasing of certain services, including cardiac surgery, to districts in April 1993. Three districts had provider units within their boundaries. No means existed for estimating the appropriate operation rate, according to need, for district populations. A method was therefore devised for calculating guideline targets. Based on the assumption that the ischaemic heart disease standardized mortality ratio (IHD SMR) is a valid proxy of the need for CABG operations and using a linear regression model, the existing district IHD SMRs and IHD hospitalization rates were used to derive guideline targets for districts, taking account of the need to raise the average operation rate for the Region to 300 per million population. Further targets using alternative Poisson regression model and weighting formulae were also derived. The derived operation targets based on the linear regression model were lower than the existing operation rate in the three provider districts and in the biggest provider's two neighbours. In all other districts, except one, targets were higher than the existing number of operations. The two further analyses produced essentially similar results. In the North Western Region wide variations in CABG operation rates existed. Access to CABG surgery in the North Western Region appears to depend on proximity to the provider districts. Operation rates should reflect need. This paper presents a method for deriving targets which take account of need.

Comparison of percutaneous transluminal coronary angioplasty outcome and hospital costs for low-volume and high-volume operators

Whether higher operator case volume is associated with improved percutaneous transluminal coronary angioplasty (PTCA) clinical and cost outcomes is the subject of this study. Hospital volume-related improvement in clinical outcomes has been shown for coronary artery bypass grafting (CABG) and PTCA. Physician case volume-related differences in clinical outcomes have not been clearly demonstrated, and differences in hospital costs have not been examined. For clinical and cost outcomes, risk-adjusted analysis of differences in PTCA outcomes has not been reported. In addition, controversy exists about the appropriate annual case volume considered adequate to maintain skills and achieve optimal clinical outcomes in performing PTCA procedures. We studied 2,350 PTCAs performed between March 1, 1991, and February 28, 1994. Physicians were divided into 2 volume groups: high (≥50 cases/year) and low (<50 cases/year). The rate of emergency CABG after PTCA was 2.1% for high- and 3.9% for low-volume operators (p = 0.009). Hospital morbidity associated with PTCA was lower in high- than in low-volume operators (6.46% vs 10.73%, p < 0.001). The risk-adjusted ratios for emergency CABG and morbidity were 2.05 (p = 0.005) and 1.79 (p < 0.001), respectively. The length of stay averaged 4.07 ± 4.54 days for high- and 4.49 ± 4.33 days for low-volume operators (p = 0.003). Hospital costs averaged $7,977 ± $7,269 for high- and $8,278 ± $6,289 for low-volume operators (p = 0.065). The risk-adjusted ratio was 1.091 (p = 0.004) for length of stay and 1.050 (p = 0.029) for cost. Thus, PTCA performed by high-volume operators is significantly less likely to require emergency CABG and is also significantly associated with lower hospital morbidity, shorter hospital length of stay, and lower hospital costs.

Coronary revascularisation: why do rates vary geographically in the UK?

To explain the reasons for geographical variation in the use of coronary revascularisation in the United Kingdom. This was a cross sectional ecological study. NHS and independent hospitals performing coronary revascularisation for the 11.6 million residents of the south east Thames, East Anglian and north western health regions in England plus Greater Glasgow, Lanarkshire, Ayr and Arran health boards in Scotland were included. All residents aged > or = 25 years in 1992-93 who underwent coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA) in either the public or private sector were included. Crude and age-sex standardised intervention rates for residents of the 42 constituent districts and boards were determined. Variation was measured using the systematic component of variation. Considerable systematic variations in district rates of CABG and PTCA existed. These variations mostly arose from differences in supply factors. Higher rate districts were characterised by being close to a regional revascularisation centre and having a local cardiologist. Demand factors such as the level of need in the population (measured by coronary heart disease mortality) and the lack of use of alternative treatments not only failed to explain the observed variation but were inversely associated with the rate of intervention--an example of the inverse care law. The finding that the residents of more socially deprived districts experienced higher intervention rates was probably subject to confounding due to their close proximity to specialist centres. If greater geographical equity of use for the same level of need is to be achieved, attention must be paid to the supply factors that determine levels of utilisation. As responsibility for purchasing these procedures is decentralised, utilisation might become even more unequal.

Assessing equity in access to health care provision in the UK: does where you live affect your chances of getting a coronary artery bypass graft?

Equity should be monitored routinely for all health care services, but ideal studies for each service would be prohibitively expensive and time consuming. A simple, quick, and cheap method for the preliminary exploration of equity in health care provision using routine data was devised. This method was illustrated by examining whether coronary artery bypass graft (CABG) operations reflect socioeconomic differences in ischaemic heart disease (IHD) mortality. Ecological comparison of operation rates was undertaken for CABG for 1991 and IHD mortality for 1981-85 by quartiles of Townsend deprivation score. North East Thames Regional Health Authority, London, UK. All residents of this region aged 35-74 were the denominator population. Numerators were 26,834 IHD deaths and 1041 CABG operations for the defined time periods. IHD mortality showed a steady, significant increase with increasing area deprivation scores for both men and women. CABG rate ratios increased linearly for women, while for men there was a U shaped pattern, being lowest for the second and third quartiles. This pattern was attenuated, but not abolished, when adjusted for geographical proximity to cardiothoracic surgical units. The ratio of CABG operations to IHD mortality by deprivation was relatively constant in women suggesting equitable provision. In men, this ratio was significantly lower for the third quartile. Inequities may exist in the provision of CABG operations for men in this region and this finding should be the stimulus for further detailed studies. Other health care systems should also examine equity in provision.

The Relation between the Volume of Coronary Angioplasty Procedures at Hospitals Treating Medicare Beneficiaries and Short-Term Mortality

Previous studies have found that hospitals at which more procedures, such as coronary-artery bypass grafting (CABG) and other vascular surgery, are performed have lower rates of mortality related to these procedures than hospitals where fewer such procedures are performed. We examined the relation between the number of percutaneous transluminal coronary angioplasty (PTCA) procedures performed at hospitals (volume) and short-term mortality in a population of 217,836 Medicare beneficiaries 65 years of age or older who underwent angioplasty in the United States from 1987 through 1990. The unadjusted in-hospital mortality among patients who underwent PTCA increased from 2.5 percent among the 10 percent of patients treated in hospitals with the highest volume of such procedures to 3.9 percent among the 10 percent of patients treated in hospitals with the lowest volume. The rate of bypass surgery after PTCA also increased, from 2.8 percent among patients in the highest-volume hospitals to 5.3 percent among those in the lowest-volume hospitals. Higher rates of mortality and CABG persisted in all the groups of patients treated in hospitals that performed fewer than 100 angioplasty procedures per year in Medicare beneficiaries; this volume in Medicare beneficiaries can be extrapolated to an overall annual volume of 200 to 400 angioplasty procedures. In a logistic-regression model, the volume of PTCA procedures at a hospital was found to be a highly significant predictor of in-hospital mortality (P < 0.001). These results suggest that if the hospitals with the lowest volume had achieved the experience and technical results of the highest-volume hospitals, 381 fewer patients would have undergone CABG and there would have been 300 fewer in-hospital deaths in the population we studied. Hospitals that perform more PTCA procedures have lower short-term mortality rates after the procedure. These data provide evidence in support of the regionalization of angioplasty services.

Racial and Community Factors Influencing Coronary Artery Bypass Graft Surgery Rates for All 1986 Medicare Patients

This study examines the differences in the rates of coronary artery bypass grafting (CABG) between white and black Medicare patients. This is a cross-sectional study with data from the 1986 Health Care Financing Administration hospital claims records on all Medicare patients, the 1988 update of the Bureau of Health Professions area resource file, and the 1985 Census Bureau's county population estimates file. Data are from all Medicare patients in the United States in 1986. Sex- and age-adjusted CABG rates for whites and blacks over the age of 65 years were computed for each of 50 states and 305 Standard Metropolitan Statistical Areas (SMSAs). Nationally the CABG rate was 27.1 per 10,000 for whites (40.4 for white men and 16.2 for white women), but only 7.6 for blacks (9.3 for black men and 6.4 for black women). Racial differences were greater in the Southeast, particularly in nonmetropolitan areas, than in other regions. Neither white nor black SMSA rates were associated with the rate of admission for acute myocardial infarction (an indication of the amount of coronary artery disease). White rates, but not black rates, were associated with the number of thoracic surgeons per 100,000 people. For patients insured by Medicare, race is strongly associated with CABG rates, and this association is greater for men than for women and greater in the Southeast than in other parts of the country. Physician supply may relate to the CABG rates for whites.

Racial and community factors influencing coronary artery bypass graft surgery rates for all 1986 Medicare patients

<h3>Objective.</h3> —This study examines the differences in the rates of coronary artery bypass grafting (CABG) between white and black Medicare patients. <h3>Design.</h3> —This is a cross-sectional study with data from the 1986 Health Care Financing Administration hospital claims records on all Medicare patients, the 1988 update of the Bureau of Health Professions area resource file, and the 1985 Census Bureau's county population estimates file. <h3>Setting.</h3> —Data are from all Medicare patients in the United States in 1986. <h3>Main Outcome Measures.</h3> —Sex- and age-adjusted CABG rates for whites and blacks over the age of 65 years were computed for each of 50 states and 305 Standard Metropolitan Statistical Areas (SMSAs). <h3>Results.</h3> —Nationally the CABG rate was 27.1 per 10000 for whites (40.4 for white men and 16.2 for white women), but only 7.6 for blacks (9.3 for black men and 6.4 for black women). Racial differences were greater in the Southeast, particularly in nonmetropolitan areas, than in other regions. Neither white nor black SMSA rates were associated with the rate of admission for acute myocardial infarction (an indication of the amount of coronary artery disease). White rates, but not black rates, were associated with the number of thoracic surgeons per 100 000 people. <h3>Conclusions.</h3> —For patients insured by Medicare, race is strongly associated with CABG rates, and this association is greater for men than for women and greater in the Southeast than in other parts of the country. Physician supply may relate to the CABG rates for whites. (<i>JAMA</i>. 1992;267:1473-1477)

Surgical standby for percutaneous transluminal coronary angioplasty: A survey of patterns of practice

To determine patterns of surgical standby for percutaneous transluminal coronary angioplasty (PTCA), a questionnaire was mailed to 196 US institutions in which PTCA and coronary artery bypass grafting (CABG) are performed regularly. Eighty-nine responses (46%) were received and comprise this report. Of responding institutions, the mean number of hospital beds was 615. In 1987, these institutions performed a mean of 337 PTCAs and 558 open-heart surgical procedures. The rate of emergency CABG for PTCA complications (occlusion, dissection, or coronary perforation) was 4.4% ± 0.3%, whereas the rate of urgent CABG (within 24 hours) for PTCA failure was 3.7% ± 0.6%. The incidence of emergency CABG for PTCA complications was higher (5.1% ± 0.6%) among low-volume PTCA centers (less than 250 cases per year) than at high-volume centers (more than 250 cases per year) (3.7% ± 0.3%; p < 0.05). The most common pattern of surgical backup was to maintain an open operating room on standby (57/89, 64%), and the second most common pattern was to make the next open operating room available, allowing operating room access within 1 to 3 hours (21/89, 24%). Nearly a third of institutions (26/89, 29%) maintained a flexible backup arrangement according to PTCA risk. Routine pre-PTCA patient evaluation by surgeon and/or anesthesiologist occurred in 38% (34/89). Fees for standby services were charged by 51% of surgical teams (45/89), 39% of anesthesia teams (35/89), and 38% of operating room facilities (34/89). Thirty-seven percent of surgeons (33/89) were dissatisfied with their present standby arrangements; sources of dissatisfaction included poor communication with cardiologists about high risk or possibly inappropriate PTCA cases, waste of operating room resources, and inadequate compensation. In summary, although PTCA infrequently requires emergent surgical revascularization, many institutions still maintain an open operating room on standby. The economic burden of this support frequently is not compensated. This survey describes current practices of surgical standby for PTCA and encourages closer examination of the total cost of PTCA.

Six- and twelve-month follow-up of the phase I thrombolysis in myocardial infarction (TIMI) trial

The Thrombolysis in Myocardial Infarction (TIMI) trial Phase I was designed to compare the efficacy and side effects of intravenous recombinant tissuetype plasminogen activator (rt-PA) and intravenous streptokinase (SK) in patients with acute myocardial infarction (AMI). As previously reported, rt-PA led to a reperfusion rate of 62% of totally occluded coronary arteries compared with 31% for SK (p <0.001). This study was not designed to determine if intravenous thrombolytic therapy decreases the mortality of AMI; however, the findings in these patients after 1 year of follow-up do permit certain insights into the impact of early reperfusion and reocclusion on the clinical course of patients with AMI. The mortality rate at 6 and 12 months was not significantly different in patients treated with rt-PA compared with SK (7.7% and 10.5% rt-PA vs 9.5% and 11.6% for SK). The frequency of recurrent AMI, coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) was similar in the 2 treatment groups. There was no significant difference in 6- and 12-month mortality or in the rate of recurrent AMI in patients who received thrombolytic therapy before compared with after 4 hours of the onset of AMI symptoms. When the results were analyzed on the basis of the patency of the infarct-related artery, irrespective of thrombolytic agent used, for those patients with patent arteries 90 minutes after the initiation of therapy, there was a trend toward a lower 6-month (5.6% vs 12.5%) and 12-month mortality (8.1% vs 14.8%) (p = 0.07). For patients with sustained patency (reperfusion without reocclusion by hosptial discharge), there was an extremely low, although insignificant, decrease in mortality at 6 and 12 months (1.9% and 3.8%) compared with patients without early reperfusion who survived to hospital discharge (3.5% and 6.0%). This extremely low mortality was not associated with an altered risk of recurrent AMI or rate of CABG, PTCA, or both, which was comparable in the 2 groups. The observed differences in mortality support the hypothesis that successful thrombolytic therapy decreases infarct size and thereby decreases the mortality of AMI.