Trends in the use of lipid-lowering medications at discharge in patients with acute myocardial infarction: 1998 to 2006

BACKGROUND

Compelling evidence demonstrates that certain lipid-lowering medications improve outcomes after acute myocardial infarction (AMI), but to what extent national utilization has increased in response to trials and guidelines has not been well studied. The objective of this study is to determine trends in the use of lipid-lowering medications at discharge for AMI.

METHODS

A time trend analysis was conducted on treatment rates with lipid-lowering medications from 1998 to 2006 in 996,364 patients with AMI hospitalized in 1,669 hospitals participating in the National Registry of Myocardial Infarction (NRMI) 3, 4, and 5.

RESULTS

Between 1998 and 2006, use of lipid-lowering medications at discharge increased from 29.3% to 83.8%, (relative risk [RR] 2.86, 95% CI 2.84-2.89, P < .0001). Increased use was observed in men (RR 2.71) and women (RR 3.17); age younger than 65 years (RR 2.32) and 65 years or older (RR 3.46); teaching (RR 2.47) and nonteaching hospitals (RR 2.96); and in all regions of the country. After adjusting for multiple other independent predictors, the temporal increase in use of lipid-lowering medications remained highly significant (RR 2.70, 95% CI 2.68-2.73, P < .0001). A significant upward jump in the rate of lipid-lowering medication use was observed most notably in month 72, corresponding to the publication on the PROVE-IT trial (Pravastatin or Atorvastatin Evaluation and Infection Therapy trial).

CONCLUSIONS

Use of lipid-lowering medications in patients hospitalized with AMI has increased substantially in the United States in the past 8 years. The increase in the lipid-lowering medication use was possibly accelerated by certain randomized clinical trial evidence demonstrating improved outcomes in this high-risk population.

Trends in presenting characteristics and hospital mortality among patients with ST elevation and non-ST elevation myocardial infarction in the National Registry of Myocardial Infarction from 1990 to 2006

BACKGROUND

Although ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (AMI) have been the focus of intense clinical investigation, limited information exists on characteristics and hospital mortality of patients not enrolled in clinical trials. Previous large databases have reported declining mortality of patients with STEMI but have not noted substantial mortality change among those with NSTEMI.

METHODS

The National Registry of Myocardial Infarction enrolled 2,515,106 patients at 2,157 US hospitals from 1990 to 2006. Of these, we evaluated 1,950,561 with diagnoses reflecting acute myocardial ischemia on admission.

RESULTS

From 1990 to 2006, the proportion of NSTEMI increased from 14.2% to 59.1% (P < .0001), whereas the proportion of STEMI decreased. Mean age increased (from 64.1 to 66.4 years, P < .0001) as did the proportion of females (from 32.4% to 37.0%, P < .0001). Patients were less likely to report prior angina, prior AMI, or family history of coronary artery disease but more likely to report history of diabetes, hypertension, current smoking, heart failure, prior revascularization, stroke, and hyperlipidemia. From 1994 to 2006, hospital mortality fell among all patients (10.4% to 6.3%), STEMI (11.5% to 8.0%), and NSTEMI (7.1% to 5.2%), (all P < .0001). After adjustment for baseline covariates, hospital mortality fell among all patients by 23.6% (odds ratio [OR] 0.764, 95% CI 0.744-0.785), STEMI by 24.2% (OR 0.758, 0.732-0.784), and NSTEMI by 22.6% (OR 0.774, 0.741-0.809), all P < .001.

CONCLUSIONS

This large, observational database from 1990 to 2006 shows increasing prevalence of NSTEMI and, despite higher risk profile on presentation, falling risk-adjusted hospital mortality in patients with either STEMI or NSTEMI.

Trends in reperfusion strategies, door-to-needle and door-to-balloon times, and in-hospital mortality among patients with ST-segment elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction from 1990 to 2006

BACKGROUND

Among patients with ST-segment elevation myocardial infarction (STEMI), rapid reperfusion is associated with improved mortality. As such, door-to-needle (D2N) and door-to-balloon (D2B) times have become metrics of quality of care and targets for intense quality improvement.

METHODS

The National Registry of Myocardial Infarction (NRMI) collected data regarding reperfusion therapy, its timing and in-hospital mortality among STEMI patients from 1990 through 2006.

RESULTS

Since 1990, NRMI has enrolled 1,374,232 STEMI patients at 2,157 hospitals. Among those, 774,279 (56.3%) were eligible for reperfusion upon arrival. The proportion receiving fibrinolytic therapy fell from 52.5% in 1990 to 27.6% in 2006 (P < .001), while the proportion undergoing primary percutaneous coronary intervention (pPCI) increased from 2.6% to 43.2%. Among reperfusion-eligible patients who received fibrinolytic therapy, there was a nearly linear decline in median D2N time from 59 minutes in 1990 to 29 minutes in 2006 (P < .001 for trend) as well as a decrease in mortality from 7.0% in 1994 to 6.0% in 2006 (P < .001). Among those undergoing pPCI, D2B time among nontransfer patients declined linearly from 111 minutes in 1994 to 79 minutes in 2006 (P < .001) with a decline in mortality from 8.6% to 3.1% (P < .001). The relative improvement in mortality attributable to improvements in D2N time was 16.3% and to D2B time was 7.5%.

CONCLUSIONS

Since 1990, there has been a progressive decline in D2N and D2B time among reperfusion-eligible STEMI patients. These improvements have contributed, at least in part, to a progressive decline in mortality.

Is coding for myocardial infarction more accurate now that coding descriptions have been clarified to distinguish ST-elevation myocardial infarction from non-ST elevation myocardial infarction?

Outcomes are typically graded on the basis of diagnoses coded according to the International Classification of Diseases, Ninth Revision (ICD-9). To facilitate performance measurement, the ICD-9 codes for acute myocardial infarction changed in October 2005 to completely separate non-ST elevation myocardial infarction (NSTEMI; code 410.71) and ST elevation myocardial infarction (STEMI; all other codes 410.x), yet it is unclear whether these changes have been implemented by coders. Patients in the National Registry of Myocardial Infarction (NRMI), version 5, were categorized in 2 ways: by electrocardiographic (ECG) findings and ICD-9 codes. Agreement between ECG findings and ICD-9 codes for type of myocardial infarction (STEMI or NSTEMI) was assessed before and after ICD-9 revision. Mortality rates were measured in a subgroup of patients discharged without transfer after the coding change. There were 102,679 hospitalizations before October 2005 and 63,012 hospitalizations after the coding change, among which the mean age was 66.7 years. Previously, 81% of NSTEMIs (by ECG diagnosis) were coded ICD-9 410.71; after the reclassification of code 410.71 to reflect NSTEMI, 82% of NSTEMIs were coded 410.71 (p <0.001). Overall, the correlation of ECG diagnosis with ICD-9 code improved only slightly after the coding change. In conclusion, despite more distinctly separated definitions of STEMI and NSTEMI in the new ICD-9 coding system as of October 2005, there appears to be little change in coding, which may reflect a lack of awareness of this substantial change in classification.

Clinical characteristics of dialysis patients with acute myocardial infarction in the United States: a collaborative project of the United States Renal Data System and the National Registry of Myocardial Infarction

BACKGROUND

Acute myocardial infarction (AMI) is catastrophic for dialysis patients. This study set out to determine the clinical characteristics of dialysis patients hospitalized for AMI in the United States.

METHODS AND RESULTS

This retrospective cohort study used data from the US Renal Data System (USRDS) database (n=1,285,177) and the third National Registry of Myocardial Infarction (NRMI 3) (n=537,444). AMI hospitalizations from April 1, 1998, through June 30, 2000, were identified using International Classification of Diseases, 9th edition, clinical modification, codes 410, 410.x, 410.x0, and 410.x1. The 9418 unique dialysis patients identified with AMI hospitalizations in the USRDS database were cross-matched with the NRMI registry, creating a cohort for analysis that consisted of 3049 matching patients. Clinical characteristics of dialysis and nondialysis (n=534,395) AMI patients were compared by use of the chi2 test. Of clinical significance, 44.8% of dialysis patients were diagnosed as not having acute coronary syndrome on admission, versus 21.2% of nondialysis patients; 44.4% presented with chest pain, versus 68.3% of nondialysis patients; and 19.1% had ST elevation, versus 35.9% of nondialysis patients. Cardiac arrest was twice as frequent for dialysis patients (11.0% versus 5.0%), and in-hospital death was nearly so (21.3% versus 11.7%). In a logistic regression model, the odds ratio for in-hospital death for dialysis versus nondialysis patients was 1.498 (95% CI, 1.340 to 1.674).

CONCLUSIONS

Dialysis patients hospitalized for AMI differ strikingly from nondialysis patients, which possibly explains their poor outcomes. Intensive efforts for early, accurate recognition of AMI in dialysis patients are warranted.

Current incidence and clinical outcomes of bivalirudin administration among patients undergoing primary coronary intervention for stent thrombosis elevation acute myocardial infarction

BACKGROUND

Multiple antithrombotic options are available for patients undergoing primary percutaneous coronary interventions for stent thrombosis elevation acute myocardial infarction. Current utilization and outcomes of antithrombotic agents for primary percutaneous coronary intervention, including bivalirudin, have not been defined.

METHODS

A total of 84 471 patients were reported from 439 hospitals to the National Registry of Myocardial Infarction-5 registry between April 2004 and June 2005. Consecutive patients undergoing primary percutaneous coronary interventions for stent thrombosis elevation acute myocardial infarction (n=7629 at 231 United States percutaneous coronary intervention capable hospitals) comprised the population analyzed. We examined antithrombotic strategies and the occurrence of adverse cardiac events stratified according to the use of bivalirudin. Logistic regression was performed to control for differences between three antithrombotic therapy treatment groups.

RESULTS

Glycoprotein IIbIIIa inhibitors were used nearly ubiquitously, but given prior to percutaneous coronary interventions in only 36% of patients. Less than one-quarter of patients received clopidogrel prior to percutaneous coronary interventions. Bivalirudin was used in 4.2% of patients (n=320) undergoing primary percutaneous coronary intervention during this time period. Patients treated with bivalirudin were more likely to be elderly (P=0.03), have a history of prior bleeding (P=0.003) and stroke (P=0.06). Major adverse events and bleeding complications were similar in antithrombotic therapy groups (bleeding: bivalirudin 7.8% versus nonbivalirudin 7.5%, P=0.85). The adjusted outcomes were also similar after confining the analysis to bivalirudin patients who had not received any glycoprotein IIbIIIa inhibitors (n=143).

CONCLUSIONS

Contemporary primary percutaneous coronary intervention includes mainly clopidogrel and eptifibatide initiated at the time of percutaneous coronary intervention. Patients who received bivalirudin were at higher risk and had similar adjusted outcomes as patients in the nonbivalirudin group. Optimization of primary percutaneous coronary intervention pharmacology requires future randomized clinical trials, examining the timing and type of adjunctive antithrombotic agents.

Hospital Delays in Reperfusion for ST-Elevation Myocardial Infarction

Background— It has been suggested that the survival benefit associated with primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction may be attenuated if door-to-balloon (DB) time is delayed by >1 hour beyond door-to-needle (DN) times for fibrinolytic therapy. Whereas DB times are rapid in randomized trials, they are often prolonged in routine practice. We hypothesized that in clinical practice, longer DB-DN times would be associated with higher mortality rates and reduced PPCI survival advantage. We also hypothesized that in addition to PPCI delays, patient risk factors would significantly modulate the relative survival advantage of PPCI over fibrinolysis.

Methods and Results— DB-DN times were calculated by subtracting median DN time from median DB time at a hospital using data from 192 509 patients at 645 National Registry of Myocardial Infarction hospitals. Hierarchical models that adjusted simultaneously for both patient-level risk factors and hospital-level covariates were used to evaluate the relationship between PCI-related delay, patient risk factors, and in-hospital mortality. Longer DB-DN times were associated with increased mortality ( P <0.0001). The DB-DN time at which mortality rates with PPCI were no better than that of fibrinolysis varied considerably depending on patient age, symptom duration, and infarct location.

Conclusions— As DB-DN times increase, the mortality advantage of PPCI over fibrinolysis declines, and this advantage varies considerably depending on patient characteristics. As indicated in the American College of Cardiology/American Heart Association guidelines, both the hospital-based PPCI-related delay (DB-DN time) and patient characteristics should be considered when a reperfusion strategy is selected.

Early Coronary Revascularization Diminishes the Risk of Ischemic Stroke With Acute Myocardial Infarction

Background and Purpose— Ischemic stroke is an uncommon but devastating complication of myocardial infarction (MI). It is possible that delay in the acute revascularization of these patients influences the risk of peri-MI ischemic stroke independent of size of infarction or residual ventricular function. The influence of the timing and type of revascularization on risk of ischemic stroke in the patient with MI has not previously been assessed.

Methods— We used the National Registry of Myocardial Infarction 3 and 4 databases to identify 45 997 subjects who received thrombolytic therapy and 47 876 patients who were treated with primary percutaneous transluminal coronary angioplasty for MI. In-hospital ischemic stroke occurred in 248 (0.54%) and 150 (0.31%) patients in the two groups, respectively. Patients were stratified based on time from presentation to initial therapy.

Results— A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes was associated with a lower risk of ischemic stroke (odds ratio, 0.58; 95% CI, 0.36–0.94). Primary angioplasty within 90 minutes of arrival was associated with a nonsignificant trend toward lower stroke risk (odds ratio, 0.68; 95% CI, 0.41–1.12). Interestingly, his benefit of early reperfusion therapy did not appear to be related to improvements in left ventricular function.

Conclusion— Risk of in-hospital ischemic stroke with MI is closely tied to the time to revascularization with both thrombolytic and percutaneous transluminal coronary angioplasty therapies. Early revascularization is independently predictive of a lower risk of ischemic stroke, but the mechanism of this does not appear to be related to improved cardiac function. The records of 45 997 subjects who received thrombolytic therapy and 47 876 patients who were treated with primary percutaneous transluminal coronary angioplasty for myocardial infarction were analyzed to determine the relationship between time to revascularization and the occurrence of ischemic stroke. A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes of presentation was associated with a lower risk of ischemic stroke, and angioplasty within 90 minutes was similarly associated with a nonsignificant trend toward lower stroke risk.

Effect of door-to-balloon time on mortality in patients with ST-segment elevation myocardial infarction

OBJECTIVES

We sought to determine the effect of door-to-balloon time on mortality for patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

BACKGROUND

Studies have found conflicting results regarding this relationship.

METHODS

We conducted a cohort study of 29,222 STEMI patients treated with PCI within 6 h of presentation at 395 hospitals that participated in the National Registry of Myocardial Infarction (NRMI)-3 and -4 from 1999 to 2002. We used hierarchical models to evaluate the effect of door-to-balloon time on in-hospital mortality adjusted for patient characteristics in the entire cohort and in different subgroups of patients based on symptom onset-to-door time and baseline risk status.

RESULTS

Longer door-to-balloon time was associated with increased in-hospital mortality (mortality rate of 3.0%, 4.2%, 5.7%, and 7.4% for door-to-balloon times of < or =90 min, 91 to 120 min, 121 to 150 min, and >150 min, respectively; p for trend <0.01). Adjusted for patient characteristics, patients with door-to-balloon time >90 min had increased mortality (odds ratio 1.42; 95% confidence interval [CI] 1.24 to 1.62) compared with those who had door-to-balloon time < or =90 min. In subgroup analyses, increasing mortality with increasing door-to-balloon time was seen regardless of symptom onset-to-door time (< or =1 h, >1 to 2 h, >2 h) and regardless of the presence or absence of high-risk factors.

CONCLUSIONS

Time to primary PCI is strongly associated with mortality risk and is important regardless of time from symptom onset to presentation and regardless of baseline risk of mortality. Efforts to shorten door-to-balloon time should apply to all patients.

Impact of pregnancy on women with cystic fibrosis

BACKGROUND

Improvements in the health and survival of patients with cystic fibrosis (CF) have led to increasingly normal lifestyles, including successful pregnancies in women with CF. Concern exists among care providers about the impact of pregnancy on the health of women with CF.

STUDY OBJECTIVES

We examined data from a large longitudinal observational study, the Epidemiologic Study of Cystic Fibrosis (ESCF), to characterize health outcomes and CF-related therapies in women who became pregnant.

DESIGN

This analysis was conducted using ESCF data from 1995 to 2003.

PATIENTS

A total of 216 women, aged 15 to 38 years, who met the criteria for a qualifying pregnancy, were compared with a matched group of never-pregnant women during three time periods (ie, baseline, during pregnancy, and follow-up).

INTERVENTIONS

None.

RESULTS

The baseline pulmonary function (FEV(1)) values were 74.5% and 66.4% predicted, respectively, in the pregnant and nonpregnant women. Declines in FEV(1) values of 6.8% and 4.7%, respectively, were observed from baseline to follow-up in the pregnant and nonpregnant women (p = 0.61). During pregnancy, outpatient visits were 33% more frequent compared to baseline and 62% more frequent than in the nonpregnant group (7.19 vs 4.45, respectively, visits annually). Annual rates of respiratory exacerbation and hospitalization were similar at baseline but increased during pregnancy. The prevalence of treatment for diabetes more than doubled, from 9.3% at baseline to 20.6% during pregnancy, and was 14.4% at follow-up. In contrast, 18.7% of the never-pregnant women were being treated for diabetes at baseline, rising to 25.2% at follow-up.

CONCLUSIONS

These findings suggest that, over the same time period, women with CF who become pregnant experienced similar respiratory and health trends as nonpregnant women. However, pregnant women use a greater number of therapies and receive more intense monitoring of their health. These findings have implications for clinicians providing prepregnancy counseling for women with CF.

Application of the Thrombolysis in Myocardial Infarction risk index in non-ST-segment elevation myocardial infarction: evaluation of patients in the National Registry of Myocardial Infarction

OBJECTIVES

The purpose of this research was to evaluate the Thrombolysis In Myocardial Infarction risk index (TRI) to characterize the risk of death among patients with non-ST-segment elevation myocardial infarction (NSTEMI).

BACKGROUND

The TRI, calculated from baseline age, systolic pressure, and heart rate, was established in patients with ST-segment elevation myocardial infarction (STEMI) and is predictive of mortality. Patients presenting with NSTEMI are increasing compared to STEMI and constitute a group with varied risk.

METHODS

The TRI was calculated in 337,192 patients from the National Registry of Myocardial Infarction with NSTEMI. Values and outcomes were compared with 153,486 patients with STEMI classified by reperfusion status. Comparisons of baseline characteristics and clinical outcomes stratified by TRI were made.

RESULTS

There was a graded relationship between the TRI and mortality in patients with NSTEMI with a >30-fold difference in mortality rates between lowest and highest deciles (p < 0.0001). The index showed good discrimination (c = 0.73). Overall mortality in the group with NSTEMI was higher (10.9%) than patients with STEMI treated with (6.6%) but lower than for STEMI patients not receiving reperfusion therapy (18.7%). The higher risk in comparison to patients with STEMI treated with reperfusion therapy was explained largely by the higher-risk profile of the population with NSTEMI.

CONCLUSIONS

There is a graded relationship between TRI and mortality in patients with NSTEMI. This simple risk index provides important information about mortality in patients across the spectrum of myocardial infarction, STEMI and NSTEMI. Early identification of NSTEMI patients who are at high risk of in-hospital mortality may provide clinicians with important information for initial triage and treatment.

Use of combination evidence-based medical therapy prior to acute myocardial infarction (from the National Registry of Myocardial Infarction-4)

Utilization rates of aspirin, beta blockers, angiotensin-converting enzyme inhibitors, and statins singly and as part of a multidrug regimen before hospitalization were measured in 109,540 patients with a history of coronary artery disease presenting with acute myocardial infarction to 1,283 hospitals participating in the National Registry of Myocardial Infarction-4. The profile of patients receiving none or only 1 of these therapies was compared with that of patients receiving any 3 or all 4 agents. Most patients (58%) with a history of coronary artery disease presenting with acute myocardial infarction were on none or only 1 of these effective medications at hospital admission. Only 21% of patients were on >or=3 of these therapies. Older age, female gender, and Medicare or no insurance coverage was significantly associated with previous receipt of <or=1 agent. Patients from New England or with a history of diabetes mellitus, hypertension, or hyperlipidemia were more likely to have received >or=3 of these therapies. In conclusion, data from this large national registry have indicated that most patients with a history of CAD were not receiving the recommended combination of cardiac medications before their AMI.

Sex and racial differences in the management of acute myocardial infarction, 1994 through 2002

BACKGROUND

Although increased attention has been paid to sex and racial differences in the management of myocardial infarction, it is unknown whether these differences have narrowed over time.

METHODS

With the use of data from the National Registry of Myocardial Infarction, we examined sex and racial differences in the treatment of patients who were deemed to be "ideal candidates" for particular treatments and in deaths among 598,911 patients hospitalized with myocardial infarction between 1994 and 2002.

RESULTS

In the unadjusted analysis, sex and racial differences were observed for rates of reperfusion therapy (for white men, white women, black men, and black women: 86.5, 83.3, 80.4, and 77.8 percent, respectively; P<0.001), use of aspirin (84.4, 78.7, 83.7, and 78.4 percent, respectively; P<0.001), use of beta-blockers (66.6, 62.9, 67.8, and 64.5 percent; P<0.001), and coronary angiography (69.1, 55.9, 64.0, and 55.0 percent; P<0.001). After multivariable adjustment, racial and sex differences persisted for rates of reperfusion therapy (risk ratio for white women, black men, and black women: 0.97, 0.91, and 0.89, respectively, as compared with white men) and coronary angiography (relative risk, 0.91, 0.82, and 0.76) but were attenuated for the use of aspirin (risk ratio, 0.97, 0.98, and 0.94) and beta-blockers (risk ratio, 0.98, 1.00, and 0.96); all risks were unchanged over time. Adjusted in-hospital mortality was similar among white women (risk ratio, 1.05; 95 percent confidence interval, 1.03 to 1.07) and black men (risk ratio, 0.95; 95 percent confidence interval, 0.89 to 1.00), as compared with white men, but was higher among black women (risk ratio, 1.11; 95 percent confidence interval, 1.06 to 1.16) and was unchanged over time.

CONCLUSIONS

Rates of reperfusion therapy, coronary angiography, and in-hospital death after myocardial infarction, but not the use of aspirin and beta-blockers, vary according to race and sex, with no evidence that the differences have narrowed in recent years.

Trends in management and outcomes of patients with acute myocardial infarction complicated by cardiogenic shock

CONTEXT

Early mechanical revascularization in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock is a therapeutic strategy that reduces mortality. It has been a class I recommendation in guidelines from the American College of Cardiology and the American Heart Association since 1999 for patients younger than 75 years. However, little is known about implementation of these guidelines in practice.

OBJECTIVES

To assess trends in early revascularization and mortality for patients with cardiogenic shock complicating AMI and to determine whether the national guidelines affect revascularization rates.

DESIGN, SETTING, AND PATIENTS

Prospective, observational study of 293,633 patients with ST-elevation myocardial infarction (25,311 [8.6%] had cardiogenic shock; 7356 [29%] had cardiogenic shock at hospital presentation) enrolled in the National Registry of Myocardial Infarction (NRMI) from January 1995 to May 2004 at 775 US hospitals with revascularization capability (defined as the capability to perform cardiac catheterization, percutaneous coronary intervention [PCI], and open-heart surgery).

MAIN OUTCOME MEASURES

Management patterns and in-hospital mortality rates.

RESULTS

There was an increase in primary PCI rates from 27.4% to 54.4% (P<.001) in hospitals with revascularization capability that paralleled the change in PCI for ST-elevation myocardial infarction. There was no significant change in rates of immediate coronary artery bypass graft surgery (from 2.1% to 3.2%). Propensity-adjusted multivariable analyses demonstrated that primary PCI was associated with a decreased odds of death during hospitalization (odds ratio, 0.46; 95% confidence interval, 0.40-0.53). There were no differences in the rates of change in revascularization rates based on the date when the guidelines were released regardless of patient age. Overall in-hospital cardiogenic shock mortality decreased from 60.3% in 1995 to 47.9% in 2004 (P<.001).

CONCLUSIONS

The use of PCI for patients with cardiogenic shock was associated with improved survival in a large group of hospitals with revascularization capability. The American College of Cardiology and American Heart Association guidelines had no detectable temporal impact on revascularization rates. These findings support the need for increased adherence to these guidelines.

Racial differences in reperfusion therapy use in patients hospitalized with myocardial infarction: a regional phenomenon

BACKGROUND

Racial differences in reperfusion therapy use among patients hospitalized with myocardial infarction (MI) have been previously reported as national phenomenon. However, it is unclear whether racial differences in treatment vary by region.

METHODS

Using data from the National Registry of Myocardial Infarction-2 and -3, a cohort of patients hospitalized with MI in the United States between 1994 and 2000, we sought to determine whether racial differences in reperfusion therapy use varied by geographic region in patients eligible for reperfusion therapy with no clinical contraindications to treatment (n = 204 230).

RESULTS

Black patients had lower crude rates of reperfusion therapy than white patients (66.5% vs 69.9%, -3.3% racial difference, 99% CI -4.4% to -2.2%) overall. However, racial differences in reperfusion therapy use varied by geographic region. Reperfusion therapy rates were similar for black patients and white patients in the Northeast (67.9% black vs 65.3% white, +2.7% racial difference, 99% CI -0.5% to 5.8%) and statistically comparable for patients in the Midwest (68.3% black vs 69.0% white, -0.7% racial difference, 99% CI -2.9% to 1.5%) and West (70.7% black vs 72.6% white, -1.9% racial difference, 99% CI -5.1% to 1.2%). Racial differences in reperfusion therapy use were greatest for patients hospitalized in the South (64.5% black vs 71.7% white, -7.1% racial difference, 99% CI -8.7% to -5.6%). Racial differences were reduced, but geographic variations in racial differences persisted after multivariable adjustment.

CONCLUSIONS

Lower rates of reperfusion therapy use among black patients with MI do not reflect a national pattern of racial differences in treatment, but a practice pattern predominantly attributable to the South.

ST-segment depression on the initial electrocardiogram in acute myocardial infarction-prognostic significance and its effect on short-term mortality: A report from the National Registry of Myocardial Infarction (NRMI-2, 3, 4)

This study analyzed 255,256 patients who had acute myocardial infarction and were enrolled in the National Registry of Myocardial Infarction 2, 3, and 4 (1994 to 2002). The objective was to determine in-hospital mortality rate among patients who had ST-segment depression on the initial electrocardiogram. Patients who had ST-segment depression had an in-hospital mortality rate (15.8%) similar to that of patients who had ST-segment elevation or left bundle branch block (15.5%). After adjusting for observed differences, ST-segment depression was associated with only a slightly lower odds ratio (0.91) of mortality compared with ST-segment elevation or left bundle branch block.

Early Withdrawal of Statin Therapy in Patients With Non–ST-Segment Elevation Myocardial InfarctionNational Registry of Myocardial Infarction

BACKGROUND

There is increasing interest in the non-lipid-lowering effects of statins and their effect on outcomes in patients with acute coronary syndrome. It has been suggested that withdrawal of statin therapy during an acute coronary syndrome may attenuate any benefits of pretreatment, thereby providing indirect evidence of the importance of their non-lipid-lowering effects.

METHODS

This observational study compared the demographic and clinical characteristics and hospital outcomes in patients with non-ST-segment elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction 4. Comparison groups consisted of patients previously receiving statins who also received statins within 24 hours of hospital admission (n = 9,001), patients previously using statins in whom therapy was discontinued (n = 4,870), and patients who did not receive statins at any time before or during hospitalization (n = 54,635).

RESULTS

Of 13,871 patients receiving statins before hospital admission, 35.1% had treatment withdrawn during the first 24 hours of hospitalization. These patients had increased hospital morbidity and mortality rates relative to patients in whom therapy was continued, with higher rates of heart failure, ventricular arrhythmias, shock, and death. In multivariate analyses, these patients were at statistically significant increased risk of hospital death compared with those continuing statin therapy and at similar risk compared with those not receiving statins before or during hospitalization.

CONCLUSIONS

Withdrawal of statin therapy in the first 24 hours of hospitalization for non-ST-segment elevation myocardial infarction is associated with worse hospital outcomes. In the absence of data from randomized clinical trials, our findings suggest that statin therapy should be continued during hospitalization for myocardial infarction unless strongly contraindicated.

Performance of the thrombolysis in myocardial infarction risk index in the National Registry of Myocardial Infarction-3 and -4: a simple index that predicts mortality in ST-segment elevation myocardial infarction

OBJECTIVES

We sought to evaluate a simple risk index based on age and vital signs in a community sample of patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

A simple risk index based on age and vital signs (heart rate x [age/10](2)/systolic blood pressure) developed from patients with STEMI accurately predicts mortality in clinical trials of fibrinolysis. The application of such a tool in an unselected population is necessary to evaluate its utility in clinical practice.

METHODS

To evaluate the Thrombolysis In Myocardial Infarction (TIMI) risk index for routine practice, we tested it in the National Registry of Myocardial Infarction (NRMI)-3 and -4. The risk index was evaluated as a continuous variable in patients with STEMI from NRMI and in subgroups based on age and reperfusion status.

RESULTS

A total of 153,486 patients with STEMI were eligible. As anticipated, STEMI patients in NRMI had a higher risk index profile, as compared with those in the clinical trial (median 26.9 vs. 20, p < 0.0001). Classification of NRMI patients with STEMI into risk groups revealed a significant graded relationship with mortality (0.9% to53.2%, p(trend) < 0.0001, c statistic 0.79). The discriminatory capacity of the risk index was particularly strong in the 81,679 patients receiving reperfusion therapy (0.6% to60%, p(trend) < 0.0001, c statistic 0.81). For the 71,807 patients not receiving reperfusion therapy, a strong graded relationship remained (1.9% to 52.2%, p(trend) < 0.0001, c statistic 0.71). Among the elderly, although the distribution of scores was shifted toward higher risk, the performance remained (0% to 53.1%, p(trend)< 0.0001, c statistic 0.71).

CONCLUSIONS

A simple risk index from baseline clinical variables routinely obtained at the first patient encounter predicted mortality in a large unselected heterogeneous group of patients with STEMI.

Comparability of quality-of-care indicators for emergency coronary angioplasty in patients with acute myocardial infarction regardless of on-site cardiac surgery (report from the National Registry of Myocardial Infarction)

Initial reports have suggested that primary percutaneous coronary intervention (PCI) can be performed safely in selected hospitals without on-site cardiac surgery; however, quality-of-care indicators for primary PCI in these institutions is unknown. Therefore, symptom onset-to-door intervals, door-to-balloon times, compliance with American College of Cardiology/American Heart Association (ACC/AHA) management guidelines, and in-hospital mortality were evaluated in 108,132 patients in 3 hospital settings in the National Registry of Myocardial Infarction: (1) diagnostic laboratories only (n = 47), (2) elective PCI only (n = 50), and (3) elective PCI and cardiac surgery (n = 562). Mean symptom onset-to-door intervals (127 minutes, 95% confidence interval 118 to135; 134 minutes, 95% confidence interval 125 to 142; and 140 minutes, 95% confidence intervals 138 to 141; p = 0.01) and door-to-balloon intervals (104 minutes, 95% confidence interval 101 to 108; 116 minutes, 95% confidence interval 112 to 119; and 119 minutes, 95% confidence interval 118 to 120; p <0.0001) were shorter in hospitals without cardiac surgery. Adherence to ACC/AHA guidelines for medications within the first 24 hours (aspirin, beta blockers, angiotensin-converting enzyme inhibitors) was greater in hospitals without cardiac surgery. There were comparable in-hospital mortality rates (3.2%, 4.2%, and 4.8%, respectively; p = 0.07) for patients with similar Thrombolysis In Myocardial Infarction risk scores; however, 4.7% of patients treated with primary PCI in hospitals without cardiac surgery were transferred to another institution. Thus, hospitals performing primary PCI without on-site cardiac surgery that participated in this registry have quality-of-care indicators and adherence to ACC/AHA management guidelines that are comparable to hospitals with on-site cardiac surgery. The lack of on-site cardiac surgery does not appear to adversely affect quality-of-care indicators in primary PCI.

What are hospitals doing to increase beta-blocker use?

BACKGROUND

Despite the many proposed methods for improving quality, little is known about which methods are being applied in practice across the United States or their perceived effectiveness.

METHODS

A descriptive, cross-sectional analysis of data from a telephone survey of quality improvement staff in 234 randomly selected hospitals participating in the National Registry of Myocardial Infarction was conducted to examine the prevalence and perceived effectiveness of various quality improvement interventions directed at increasing beta-blocker use after acute myocardial infarction.

RESULTS

The mean and median number of quality improvement interventions directed at beta-blocker use in the past 4 years was 5.0 per hospital. The most commonly reported effort was performance reporting about beta-blocker use (87.9%), although only 26.7% used physician-specific performance reporting. More than half the hospitals implemented clinical pathways (58.1%), standing orders (56.8%), or care coordinators (50.4%). Care coordinators (63.4%) and computer support systems (61.6%) were most frequently rated as "very effective." Clinical pathways (24.2%), counseling physicians who had poor performance (26.9%), and reminder forms (23.0%) were most frequently rated as not effective.

CONCLUSIONS

Substantial variation in the types of quality improvement efforts implemented to increase beta-blocker use and perceived effectiveness were evident.

Use of emergency medical services in acute myocardial infarction and subsequent quality of care: observations from the National Registry of Myocardial Infarction 2

BACKGROUND

National practice guidelines strongly recommend activation of the 9-1-1 Emergency Medical Systems (EMS) by patients with symptoms consistent with an acute myocardial infarction (MI). We examined use of the EMS in the United States and ascertained the factors that may influence its use by patients with acute MI.

METHODS AND RESULTS

From June 1994 to March 1998, the National Registry of Myocardial Infarction 2 enrolled 772 586 patients hospitalized with MI. We excluded those who transferred in, arrived at the hospital >6 hours from symptom onset, or who were in cardiogenic shock. We compared baseline characteristics and initial management for patients who arrived by ambulance versus self-transport. EMS was used in 53.4% of patients with MI, a proportion that did not vary significantly over the 4-year study period. Nonusers of the EMS were on average younger, male, and at relatively lower risk on presentation. In addition, payer status was significantly associated with EMS use. Use of EMS was independently associated with slightly wider use of acute reperfusion therapies and faster time intervals from door to fibrinolytic therapy (12.1 minutes faster, P<0.001) or to urgent PTCA (31.2 minutes faster, P<0.001).

CONCLUSIONS

Only half of patients with MI were transported to the hospital by ambulance, and these patients had greater and significantly faster receipt of initial reperfusion therapies. Wider use of EMS by patients with suspected MI may offer considerable opportunity for improvement in public health.