Recurrent atherosclerotic cardiovascular disease events preventable with guideline recommended lipid-lowering treatment following myocardial infarction

Background

The 2018 American Heart Association/American College of Cardiology (AHA/ACC) cholesterol guideline provides recommendations for lipid-lowering therapy (LLT) including statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) to prevent recurrent atherosclerotic cardiovascular disease (ASCVD) events in adults with established ASCVD. Many adults with ASCVD who are recommended to take statins, ezetimibe and/or PCSK9i do not receive these medications.

Purpose

To estimate the number of recurrent ASCVD events potentially prevented by population-wide use of guideline recommended LLT following a myocardial infarction (MI).

Methods

We simulated the population-wide impact of receipt of 2018 AHA/ACC cholesterol guideline recommended LLT over 3 and 5 years among US adults with government health insurance through Medicare or commercial health insurance following hospital discharge for MI. We used data from patients with an MI hospitalization in 2018–2019 to estimate the percentage receiving guideline recommended LLT defined by having the medications available to take in the 30 days after their discharge date. We used data from patients with an MI hospitalization in 2013–2016 to estimate the 3 and 5-year cumulative incidence of recurrent ASCVD events (i.e., MI, coronary revascularization or ischemic stroke). The reduction in ASCVD events associated with guideline recommended LLT was estimated from a meta-analysis by the Cholesterol-Lowering Treatment Trialists Collaboration. We conducted a sensitivity analysis estimating the number and percentage of ASCVD events prevented if LLT recommendations from the 2019 European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) cholesterol guideline were followed. We repeated all analyses with recurrent coronary heart disease (i.e., MI or coronary revascularization) and ischemic stroke events as separate outcomes.

Results

Among 279,395 adults with an MI hospitalization in 2018–2019 (mean age 75 years, 54% men, mean low-density lipoprotein cholesterol 92 mg/dL), 27% were receiving guideline recommended LLT. With current lipid-lowering medication use, we estimated that 70,698 (95% CI: 70,311–71,077) and 89,255 (95% CI: 88,841–89,730) ASCVD events would occur in 3 and 5 years, respectively, after MI hospital discharge (Table, top panel). If all patients were to receive 2018 AHA/ACC guideline recommended LLT, the number of ASCVD events was estimated to be reduced by 21.6%, representing 15,264 (95% CI: 14,451–16,679) events prevented over 3 years and 19,271 (95% CI: 18,245–21,055) events prevented over 5 years. A higher number of recurrent ASCVD events were estimated to be averted following the LLT recommendations of the 2019 ESC/EAS cholesterol guideline (Table, bottom panel).

Conclusions

Population-wide implementation of guideline recommended LLT in adults with an MI hospitalization could prevent a substantial number of recurrent ASCVD events.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen Inc.

P3518Men with heart failure have higher readmission rates: a closer review of sex and gender based analyses

Background

There has been increased attention on reducing hospital readmission rates. However, little is known about any difference in readmission rates in heart failure by sex, although evidence exists demonstrating differences in the etiology of heart failure. As a result, strategies to optimize readmission reduction programs and care strategies for women and men remain unclear.

Purpose

(1) To identify studies examining readmission rates according to sex, and (2) to provide a qualitative overview of possible considerations for the impact of sex or gender.

Methods

A scoping protocol was developed using the Arksey and O'Malley framework and the Joanna Briggs Institute methodology. Our search strategy was reviewed according to the peer-review of electronic search strategy (PRESS) checklist. Full text articles published between 2002 and 2017 and drawn from multiple databases (i.e. MEDLINE, EMBASE), grey literature (i.e. National Technical Information, Duck Duck Go), and experts were consulted for additional articles. Screening criteria were established a priori. Once an acceptable inter-rater agreement was established at 80% by two independent reviewers, articles were screened for potential eligibility. A descriptive analytical method was employed to chart primary research articles. Articles were considered relevant if the cohort consisted of adult heart failure patients who were readmitted after an index hospitalization and a sex/gender-based analysis was performed.

Results

The literature search yielded 5887 articles, of which 746 underwent full text assessment for eligibility. Of 164 eligible articles, 34 studies addressed the primary outcome, 103 studies considered sex differences as a secondary outcome and 25 studies included disaggregated data for sex but no subsequent interaction was reported. Good inter-rater agreement was reached: 83% for title and abstract screening; 88% for full text review; kappa: 0.69 (95% CI: 0.526–0.851). Twelve of 34 studies included for the primary outcome reported higher readmission rates for men compared to five studies reporting higher readmission rates for women. However, there were differential readmission rates that were dependent on duration of follow-up. Women were more likely to experience higher readmission rates than men when time to event was less than one year. Readmission rates for men were higher when follow-up was longer than one year.

Conclusion

Sex differences in readmission rates were dependent on follow up time. Most studies used composite outcomes and had short times to event, which may mask underlying effects of sex on readmission.

Acknowledgement/Funding

Ontario SPOR Support Unit

5191Recurrent coronary heart disease in the year following myocardial infarction among US men and women between 2008 and 2015

Background

Although the risk of recurrent events among adults with coronary heart disease (CHD) has declined considerably from the 1970's in the US and many Western countries, studies from the 2000's show that rates remain high. Women have lower rates of incident CHD but little is known about sex differences in recurrent events in adults with CHD.

Purpose

To examine trends in rates of recurrent myocardial infarction (MI), recurrent CHD, and all-cause mortality following a MI hospitalization between 2008 and 2015 among US men and women. Also, we compared sex differences in event rates among individuals with a MI hospitalization versus their counterparts without a history of CHD.

Methods

Data were used from 1,232,024 (53% women) US adults <65 years of age with commercial health insurance in the MarketScan database and US adults ≥66 years of age with government health insurance through Medicare who had a MI hospitalization between January 1, 2008 and December 31, 2015. For each calendar year, age-standardized sex-specific rates of recurrent MI, recurrent CHD (i.e., recurrent MI or coronary revascularization), and all-cause mortality (in Medicare only) were calculated through 365 days following the hospital discharge date for MI. In a secondary analyses, we assessed the rate of recurrent MI, CHD events and all-cause mortality among women versus men with a history of MI (n=324,283) and without a history of CHD (n=1,297,132) in 2014–2015. For these analyses, adjusted hazard ratios (95% confidence intervals) were calculated using follow-up through December 31, 2016.

Results

From 2008 to 2015, age-standardized rates over 365 days of follow-up for recurrent MI declined by 15%, from 94 to 80 per 1000 person-years, in men and by 14%, from 89 to 77 per 1000 person-years, in women. Age-standardized recurrent CHD rates decreased by 16%, from 163 to 138 per 1000 person-years, in men and by 17%, from 142 to 118 per 1000 person-years, in women. In the Medicare population, age-standardized all-cause mortality rates following MI decreased by 6%, from 446 to 421 per 1000 person-years, in men and by 3%, from 412 to 398 per 1000 person-years, in women. In the secondary analyses, the women-to-men hazard ratios for those with a history of MI and those without prior CHD were 0.97 (0.94–0.99) and 0.67 (0.65–0.69), respectively, for MI, 0.89 (0.87–0.91) and 0.52 (0.51–0.54), respectively, for CHD, and 0.84 (0.83–0.85) and 0.74 (0.73–0.75) respectively, for all-cause mortality.

Conclusion

Reductions in rates of recurrent MI, recurrent CHD, and all-cause mortality within 365 days after hospitalization for MI have been similar for US women and men. The lower risk for events comparing women versus men without prior CHD is attenuated after a MI.

Acknowledgement/Funding

The design and conduct of the study was supported through a research grant from Amgen, Inc.

P3422Contrasting the risk for atherosclerotic cardiovascular disease events among individuals with lower extremity peripheral artery disease, coronary heart disease and cerebrovascular disease

Background

Having more vascular conditions, including coronary heart disease (CHD), cerebrovascular disease and lower extremity artery disease (LEAD), may increase the risk for atherosclerosis cardiovascular disease (ASCVD) events. Specific vascular conditions may increase the ASCVD event rate more than others.

Purpose

To compare the risk for future ASCVD events associated with the number and type of vascular conditions among adults with a history of CHD, cerebrovascular disease and/or LEAD.

Methods

We analyzed data from US adults ≥19 years of age with commercial or Medicare health insurance who had a history of CHD, cerebrovascular disease and/or LEAD as of December 31, 2014 (N=901,391). Individuals were followed through December 31, 2016 (median follow-up: 2 years) for ASCVD events, including myocardial infarction, coronary revascularization, stroke, carotid revascularization and lower extremity amputation or revascularization.

Results

Among individuals included in the current analysis (mean age 63 years, 45% female), 70%, 23% and 7% had 1, 2 and 3 vascular conditions, respectively. After adjustment for sociodemographic and cardiovascular risk factors, the hazard ratio for ASCVD among individuals with 2 and 3 versus 1 vascular conditions was 1.88 (1.85, 1.92) and 2.93 (2.86, 3.00), respectively. Among individuals with 1 vascular condition, the rate of ASCVD events per 1,000 person-years was 46.5 (95% CI 44.1, 49.0), 29.6 (95% CI 29.0, 30.1) and 19.9 (95% CI 19.2, 20.8) for those with LEAD, CHD and cerebrovascular disease, respectively. The multivariable-adjusted hazard ratio (95% CI) for ASCVD events comparing individuals with LEAD only and CHD only versus those with cerebrovascular disease only was 1.84 (1.77, 1.92) and 1.12 (1.08, 1.16), respectively. Among individuals with 2 vascular conditions, the ASCVD event rate per 1,000 person-years was higher in those with LEAD and CHD (122.0, 95% CI 112.5, 132.2) and with LEAD and cerebrovascular disease (92.4, 95% CI 79.9, 106.4), versus those with CHD and cerebrovascular disease (59.1, 95% CI 54.8, 63.6). The multivariable-adjusted hazard ratio (95% CI) comparing individuals with LEAD and CHD and those with LEAD and cerebrovascular disease versus those with CHD and cerebrovascular disease was 1.48 (1.44, 1.53) and 1.49 (1.41, 1.58), respectively.

Conclusion

Among adults with vascular disease, having LEAD confers a higher risk for future ASCVD events than CHD or cerebrovascular disease and this group may benefit from more intensive risk reduction treatment.

Acknowledgement/Funding

Amgen Inc.

4113Glucose lowering drugs or strategies, major adverse cardiovascular events and heart failure outcomes, and association with weight loss - meta-analysis of large cardiovascular outcome trials

Background

Glucose lowering drugs or strategies (GLDS) have varied effects on major adverse cardiovascular events (MACE) and heart failure (HF) in cardiovascular outcomes trials. Mechanisms driving cardiovascular risk reduction remain elusive.

Methods

We searched MEDLINE, PubMed, and meeting abstracts up to 11/21/2018 for large GLDS cardiovascular outcome trials (CVOTs) in patients with or at risk for type 2 diabetes. Primary endpoints of MACE and HF were evaluated with random effects risk ratios (RR) and explored by baseline CVD subgroups and meta-regression by weight change across treatment arms.

Results

In 27 GLDS CVOTs, a total 207,820 patients, median age 63 years, 64% male, 64% CVD and 11% with prior HF were studied over a mean 3.8 years with 20,118 (10%) patients having MACE and 7,212 (4%) a HF event. Compared with standard care, GLDS overall lowered MACE (RR 0.92, P<0.ehz745.01171) but not HF (RR 1.01, P=0.91). Across GLDS, the magnitude and directionality varied modestly for MACE RR (P-int=0.07) but markedly for HF (P-int<0.ehz745.01171). Meta-regression showed a change in HF RR by 6% (95% CI 3%-9%) per 1 kg weight gain/loss between treatment arms (P=0.0006; Figure). In 9 trials of GLDS that achieved marked weight loss (lifestyle, GLP1 agonists, SGLT2 inhibitors), MACE benefit was confined to patients with baseline CVD (RR 0.89 [0.84–0.95] versus without (RR 1.02 [0.91–1.15]; P-int=0.01) with consistent HF effect (RR 0.80 [0.72–0.88] vs RR 0.76 [0.56–1.03]; P-int=0.74).

Heart Failure Risk and Changes in Weight

Conclusion

HF outcomes were improved with GLDS that lower weight. Among diabetes GLDS that lower weight, there was a robust risk reduction in atherothrombotic and heart failure events, with the MACE benefit confined to patients with established CVD.

Acknowledgement/Funding

Heart and Stroke Foundation

P652Lower use of statins among patients with peripheral artery disease compared with those with coronary heart disease

Background

Adults with atherosclerotic cardiovascular disease are recommended to take a statin to reduce their risk for future cardiovascular events. Prior studies suggest that statins are being taken by most adults with coronary heart disease (CHD). However, there are few data on the use of statins among adults with peripheral artery disease (PAD).

Purpose

To compare the use of statins among US adults with a history of PAD versus those with a history of CHD.

Methods

We conducted a retrospective cohort study among US adults ≥19 years of age with commercial or government health insurance who had a history of CHD or PAD as of December 31, 2014 (n=1,006,451, mean age 63 years, 47% male). We used pharmacy claims between January 1 and December 31, 2014 to identify use of any statin and of a high-intensity statin (i.e., atorvastatin 40–80 mg, rosuvastatin 20–40 mg, simvastatin 80 mg). Patients with a history of CHD without PAD (CHD only), both CHD and PAD, and PAD without CHD (PAD only) were analysed. Prevalence ratios for use of any statin and a high-intensity statin among those taking a statin were calculated after multivariable adjustment for sociodemographics and cardiovascular risk factors.

Results

Overall, 69.1% of patients included in the current analysis had CHD only, 21.4% had both CHD and PAD, and 9.5% had PAD only. Overall, 66.0%, 68.2% and 47.5% of patients with CHD only, CHD and PAD, and PAD only were taking a statin. After multivariable adjustment and compared to patients with CHD only, the prevalence ratio for statin use was 1.02 (95% CI 1.01, 1.02) for those with both CHD and PAD and 0.82 (95% CI 0.82, 0.83) for those with PAD only. Among patients taking a statin, 29.4% of those with CHD only, 28.6% of those with both CHD and PAD, and 17.3% of those with PAD only were taking a high-intensity dosage. Compared to patients with CHD only, the multivariable adjusted prevalence ratio for taking a high-intensity dosage was 1.05 (95% CI 1.04, 1.06) for those with both CHD and PAD and 0.71 (95% CI 0.70, 0.73) for those with PAD only.

Conclusion

Adults with PAD receive less intensive statin therapy compared with their counterparts who have CHD. Interventions aimed to increase statin use among patients with PAD are warranted.

Acknowledgement/Funding

This study was supported through a research grant from Amgen, Inc. (Thousand Oaks, CA, USA).

Disease activity in rheumatoid arthritis and the risk of cardiovascular events

OBJECTIVE

Use of several immunomodulatory agents has been associated with reduced numbers of cardiovascular (CV) events in epidemiologic studies of rheumatoid arthritis (RA). However, it is unknown whether time-averaged disease activity in RA correlates with CV events.

METHODS

We studied patients with RA whose cases were followed in a longitudinal US-based registry. Time-averaged disease activity was assessed during followup using the area under the curve of the Clinical Disease Activity Index (CDAI), a validated measure of RA disease activity. Age, sex, presence of diabetes mellitus, hypertension, or hyperlipidemia, body mass index, family history of myocardial infarction (MI), use of aspirin or nonsteroidal antiinflammatory drugs (NSAIDs), presence of CV disease, and baseline use of an immunomodulator were assessed at baseline. Cox proportional hazards regression models were examined to determine the risk of a composite CV end point that included MI, stroke, and death from CV causes.

RESULTS

A total of 24,989 patients who had been followed up for a median of 2.7 years were included in these analyses. During followup, we observed 534 confirmed CV end points, for an incidence rate of 7.8 per 1,000 person-years (95% confidence interval [95% CI] 6.7-8.9). In models adjusted for variables noted above, a 10-point reduction in the time-averaged CDAI was associated with a 21% reduction in CV risk (95% CI 13-29). These results were robust in subgroup analyses stratified by the presence of CV disease, use of corticosteroids, use of NSAIDs or selective cyclooxygenase 2 inhibitors, and change in RA treatment, as well as when restricted to events adjudicated as definite or probable.

CONCLUSION

Our findings showed that reduced time-averaged disease activity in RA is associated with fewer CV events.

Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials

BACKGROUND

The vascular and gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs), including selective COX-2 inhibitors (coxibs) and traditional non-steroidal anti-inflammatory drugs (tNSAIDs), are not well characterised, particularly in patients at increased risk of vascular disease. We aimed to provide such information through meta-analyses of randomised trials.

METHODS

We undertook meta-analyses of 280 trials of NSAIDs versus placebo (124,513 participants, 68,342 person-years) and 474 trials of one NSAID versus another NSAID (229,296 participants, 165,456 person-years). The main outcomes were major vascular events (non-fatal myocardial infarction, non-fatal stroke, or vascular death); major coronary events (non-fatal myocardial infarction or coronary death); stroke; mortality; heart failure; and upper gastrointestinal complications (perforation, obstruction, or bleed).

FINDINGS

Major vascular events were increased by about a third by a coxib (rate ratio [RR] 1·37, 95% CI 1·14-1·66; p=0·0009) or diclofenac (1·41, 1·12-1·78; p=0·0036), chiefly due to an increase in major coronary events (coxibs 1·76, 1·31-2·37; p=0·0001; diclofenac 1·70, 1·19-2·41; p=0·0032). Ibuprofen also significantly increased major coronary events (2·22, 1·10-4·48; p=0·0253), but not major vascular events (1·44, 0·89-2·33). Compared with placebo, of 1000 patients allocated to a coxib or diclofenac for a year, three more had major vascular events, one of which was fatal. Naproxen did not significantly increase major vascular events (0·93, 0·69-1·27). Vascular death was increased significantly by coxibs (1·58, 99% CI 1·00-2·49; p=0·0103) and diclofenac (1·65, 0·95-2·85, p=0·0187), non-significantly by ibuprofen (1·90, 0·56-6·41; p=0·17), but not by naproxen (1·08, 0·48-2·47, p=0·80). The proportional effects on major vascular events were independent of baseline characteristics, including vascular risk. Heart failure risk was roughly doubled by all NSAIDs. All NSAID regimens increased upper gastrointestinal complications (coxibs 1·81, 1·17-2·81, p=0·0070; diclofenac 1·89, 1·16-3·09, p=0·0106; ibuprofen 3·97, 2·22-7·10, p<0·0001; and naproxen 4·22, 2·71-6·56, p<0·0001).

INTERPRETATION

The vascular risks of high-dose diclofenac, and possibly ibuprofen, are comparable to coxibs, whereas high-dose naproxen is associated with less vascular risk than other NSAIDs. Although NSAIDs increase vascular and gastrointestinal risks, the size of these risks can be predicted, which could help guide clinical decision making.

FUNDING

UK Medical Research Council and British Heart Foundation.

New insights into the link between cardiovascular disease and depression

INTRODUCTION

Although the association between depression and cardiovascular disease (CVD) is well documented, the underlying mechanisms for this relationship remain unclear. In this paper, we present three possible models which account for the comorbidity between depression and cardiovascular disease.

MODELS

The first model outlines depression as a risk factor for CVD and the second model presents CVD as a risk factor for depression. The third model proposes a common underlying pathway related to the effects of chronic stress on the body in manifesting as depression or cardiovascular disease.

CONCLUSIONS

If the proposed model holds true, it may be possible that an intervention initiated before overt manifestations of CVD or depression become apparent, may delay or prevent the onset of these serious clinical entities.

Cardiovascular outcomes in high risk patients with osteoarthritis treated with ibuprofen, naproxen or lumiracoxib

BACKGROUND

Evidence suggests that both selective cyclooxygenase (COX)-2 inhibitors and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) increase the risk of cardiovascular events. However, evidence from prospective studies of currently available COX-2 inhibitors and non-selective NSAIDs is lacking in patients at high cardiovascular risk who are taking aspirin.

OBJECTIVE

To determine the cardiovascular outcomes in high risk patients with osteoarthritis treated with ibuprofen, naproxen or lumiracoxib.

METHODS

The Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET) of 18 325 patients with osteoarthritis comprised two parallel substudies, comparing lumiracoxib (COX-2 inhibitor) with either ibuprofen or naproxen. A post hoc analysis by baseline cardiovascular risk, treatment assignment, and low-dose aspirin use was performed. The primary composite end point was cardiovascular mortality, non-fatal myocardial infarction, and stroke at 1 year; a secondary end point was the development of congestive heart failure (CHF).

RESULTS

In high risk patients among aspirin users, patients in the ibuprofen substudy had more primary events with ibuprofen than lumiracoxib (2.14% vs 0.25%, p = 0.038), whereas in the naproxen substudy rates were similar for naproxen and lumiracoxib (1.58% vs 1.48%, p = 0.899). High risk patients not taking aspirin had fewer primary events with naproxen than with lumiracoxib (0% vs 1.57%, p = 0.027), but not for ibuprofen versus lumiracoxib (0.92% vs 0.80%, p = 0.920). Overall, CHF developed more often with ibuprofen than lumiracoxib (1.28% vs 0.14%; p = 0.031), whereas no difference existed between naproxen and lumiracoxib.

CONCLUSIONS

These data suggest that ibuprofen may confer an increased risk of thrombotic and CHF events relative to lumiracoxib among aspirin users at high cardiovascular risk. The study indicates that naproxen may be associated with lower risk relative to lumiracoxib among non-aspirin users. This study is subject to inherent limitations, and therefore should be interpreted as a hypothesis-generating study.

Early coronary angiography improves long-term survival in unstable angina

BACKGROUND

The role of early coronary angiography in the evaluation of patients with unstable angina has been controversial. This study was designed to determine the effect of early coronary angiography on long-term survival in patients with unstable angina.

METHODS

We reviewed the Olmsted County Acute Chest Pain Database, a population-based epidemiologic registry that includes all patients residing within Olmsted County who were seen for emergency department evaluation of acute chest pain from 1985 to 1992. Patients with symptoms consistent with myocardial ischemia qualifying as unstable angina were classified as undergoing early (</=7 days of index presentation) angiography or not.

RESULTS

A total of 2264 patients with symptoms consistent with unstable angina were identified with a mean duration of follow-up of 6 years; 892 underwent early angiography. Early angiography patients were younger; less likely to have heart failure; more likely to be male, hypercholesterolemic, and smokers; had prior coronary revascularization; and had a myocardial infarction at the index presentation. After baseline differences were controlled, early angiography was associated with a reduction in all-cause long-term mortality (relative risk 0.63, 95% CI 0.53-0.74). Patients at intermediate or high risk for death or myocardial infarction at presentation were most likely to benefit from early angiography.

CONCLUSION

Early angiography in the evaluation of patients with unstable angina was associated with a reduction in all-cause mortality, particularly in intermediate- and high-risk patients, in this retrospective population-based study.

Acute antithrombotic effect of a front-loaded regimen of clopidogrel in patients with atherosclerosis on aspirin

There is a need for a rapid antithrombotic effect after the administration of antiplatelet drugs in the setting of acute coronary syndromes and percutaneous interventions. Clopidogrel, a new thienopyridine derivative, is an efficient antiplatelet agent. However, the standard regimen of clopidogrel (75 mg/d) requires 2 to 3 days before significant antithrombotic effects. Patients with stable arterial disease on chronic aspirin therapy (n=20) were treated with clopidogrel either with a front-loaded regimen, 300 mg the first day and 75 mg/d the next 7 days, or with a standard regimen, 75 mg/d for 8 days. Blood thrombogenicity was assessed by quantification of platelet-thrombus formation in an ex vivo perfusion chamber, by ADP-induced platelet aggregation, and by ADP-induced fibrinogen binding. At 2 hours, mean total thrombus area with the standard regimen was not significantly reduced. In contrast, at 2 hours, the mean total thrombus area with the front-loaded regimen was significantly decreased by 23.1+/-8.5% versus baseline (P<0.05). ADP-induced platelet aggregation (with 5 and 10 micromol/L) was also significantly (P<0.05) reduced with the front-loaded regimen at 2 hours, with the mean platelet aggregation being 82.2+/-4.4% and 81.8+/-4.5%, respectively, versus baseline. Similarly, flow cytometry demonstrated a significant decrease (P<0. 05) in the ADP-induced fibrinogen binding (with 0.12 and 0.6 micromol/L) at 2 hours in this front-loaded regimen group (36.1+/-2. 0% and 53.2+/-9.3%). With the standard regimen, platelet activity was not significantly reduced at 2 hours. Our data suggest that a front-loaded regimen of clopidogrel added to aspirin achieves a significant antithrombotic effect at 2 hours in patients with known atherosclerotic disease on chronic aspirin therapy. This provides a rationale for using front-loaded clopidogrel in combination with aspirin in percutaneous coronary interventions.

Management of coronary risk factors by registered nurses versus usual care in patients with unstable angina pectoris (a chest pain evaluation in the emergency room [CHEER] substudy)

This study examined whether nurses could manage coronary risk factors in patients with unstable angina more effectively than physicians practicing usual care. Three hundred twenty-six patients were randomized in the emergency room to a 6-month program of risk factor management by a registered nurse versus participation in usual care. The nurse intervention consisted of a 30-minute counseling visit at 6 to 10 days after the chest pain episode and a second 30-minute session 1 month later. Multiple risk factors were assessed and addressed: smoking, blood lipids, blood pressure, blood glucose, physical inactivity, weight, psychological stress, and social isolation. Compared with usual care, nurse intervention patients significantly reduced both triglycerides (-29 +/- 8 vs 5 +/- 6 mg/dl; p <0.0004) and weight (-0.9 +/- 3.3 vs +0.1 +/- 2.1 kg; p = 0.0071), and had corresponding improvements in self-reported diet compliance and exercise (+34 +/- 106 vs +9 +/- 98 minutes, p = 0.0491). No significant differences between groups were observed in terms of 6-month changes in total, high-density lipoprotein, or low-density lipoprotein cholesterol, blood pressure, fasting blood glucose, percent body fat or waist-hip ratio, or psychological distress scores. The 6-month rate of recurrent events (cardiac death, out-of-hospital cardiac arrest, myocardial infarction) and/or revascularizations (coronary artery bypass surgery or coronary angioplasty) was lower in the nurse intervention group (1% vs 9%; p = 0.002). We conclude that a nurse-delivered risk factor intervention program for patients with chest pain is feasible and more effective than usual care in terms of fostering lifestyle changes that may lower coronary risk.

Sex differences in evaluation and outcome of unstable angina

CONTEXT

The existence of sex bias in the delivery of cardiac care is controversial, and little is known about the association between sex and delivery of care and outcomes at an early point in the diagnostic sequence, such as when patients present for the evaluation of chest pain.

OBJECTIVE

To test the hypothesis that female sex is negatively associated with care delivered to and outcomes of persons diagnosed as having unstable angina.

DESIGN

Inception population-based cohort study with an average of 6 years of follow-up.

SETTING

Emergency departments (EDs) in Olmsted County, Minnesota.

PATIENTS

A total of 2271 Olmsted County residents (1306 men and 965 women) who presented to the ED for the first time with symptoms meeting criteria for unstable angina between 1985 and 1992.

MAIN OUTCOME MEASURES

Use of cardiac procedures within 90 days of ED visit, overall mortality, and cardiac events (cardiac death, nonfatal myocardial infarction, nonfatal cardiac arrest, and congestive heart failure), compared by sex and Agency for Health Care Policy and Research cardiovascular risk category (low, intermediate, or high).

RESULTS

Women were older (P<.001), more likely to have a history of hypertension (P = .001), and less likely to present with typical angina (P = .004) than men. Men were more likely than women to undergo noninvasive cardiac tests (relative risk [RR], 1.27; 95% confidence interval [CI], 1.14-1.40) as well as invasive cardiac procedures (RR, 1.72; 95% CI, 1.51-1.97). After adjustment, male sex was associated with a 24% increase in the use of cardiac procedures. Survival of both men and women in the high and intermediate risk categories was significantly lower than expected per the general population (P<.001). Women had a worse outcome than men, but after multivariate adjustment, male sex was associated with a trend toward an increase in the risk of death (RR, 1.23; 95% CI, 0.99-1.54) and significantly associated with increased risk of cardiac events (RR, 1.21; 95% CI, 1.03-1.42).

CONCLUSIONS

Our population-based data indicate that after an ED visit for symptoms of unstable angina, the use of cardiac procedures was lower in women, but after taking into account baseline characteristics, men experienced worse outcomes.

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.

Strengths and limitations of meta-analysis: larger studies may be more reliable

Meta-analysis of randomized controlled trials combines information from independent studies that address a similar question to provide more reliable estimates of treatment effects. At the present time, the methodology and usefulness of meta-analysis is under scrutiny. In the first part of this paper, we summarize the limitations of meta-analysis and make suggestions for improvements. In the second part, we illustrate strengths and limitations using examples of meta-analyses and subsequent large trials that address the same question. We develop the hypothesis that the size of the meta-analysis may be a useful measure of reliability. Small meta-analyses (i.e., those with less than 200 outcome events) may only be useful for summarizing the available information and generating hypotheses for future research. The results of small meta-analyses should be regarded with caution, even if the p value shows extreme statistical significance. Larger meta-analyses (i.e., those with several hundred events) are likely to be more reliable and may be clinically useful. Well-conducted meta-analyses of large trials using individual patient data may provide the best estimates of treatment effects in the cohort overall and in clinically important subgroups.

Outcome of patients discharged from a coronary care unit with a diagnosis of "chest pain not yet diagnosed"

OBJECTIVE

To determine the outcome and 3-year mortality rate among patients discharged from a coronary care unit (CCU) with a diagnosis of "chest pain not yet diagnosed."

DESIGN

Prospective observational cohort study.

SETTING

CCU in a university teaching hospital.

PATIENTS

All 158 eligible patients discharged from the CCU between August 1986 and December 1988. Of them, 27 refused to participate and 31 did not meet the inclusion criteria because of significant co-morbidity or transportation difficulties.

INTERVENTIONS

Evaluation with maximal and thallium exercise stress testing and four major gastrointestinal (GI) investigations: 24-hour intraesophageal pH monitoring, upper GI endoscopy with biopsy, esophageal motility studies and an upper GI barium series.

OUTCOME MEASURES

Results of investigations and incidence of recurrent chest pain, CCU readmission, coronary angiography, coronary artery bypass surgery, myocardial infarction and death at 6, 12, 24 and 36 months after the index visit.

RESULTS

Of the patients enrolled in the study 79% (79/100) had a normal exercise thallium stress test result, 74% (68/92) had an abnormal result from the 24-hour pH monitoring, 87% (82/94) had abnormal endoscopic results, 90% (84/93) had abnormal manometric results, and 89% (83/93) had signs of reflux with the barium series. At 3 years 50 patients had recurrent chest pain and 3 underwent coronary artery bypass surgery. Three patients died over the 3 years, all of noncardiac causes.

CONCLUSION

Many patients discharged from the CCU with a diagnosis of chest pain not yet diagnosed have a high incidence of esophageal disorders and a very low 3-year mortality rate. More research into the early and effective identification and management of patients with such a diagnosis is needed.

Influence of coronary heart disease on morbidity and mortality after lower extremity revascularization surgery: a population-based study in Olmsted County, Minnesota (1970-1987)

OBJECTIVES

The aim of this study was to evaluate the short- and long-term postoperative cardiac outcome of patients undergoing lower extremity revascularization surgery in a geographically defined patient group.

BACKGROUND

Among patients with peripheral vascular disease, cardiac events have an important effect on long-term outcome after peripheral vascular surgery. However, long-term outcome is poorly documented.

METHODS

We examined the entire community medical records of 173 residents of Olmsted County, Minnesota, who underwent peripheral artery bypass surgery between 1970 and 1987 and were followed up to January 1, 1991. Patients were allocated to subgroups of 60 patients with and 106 patients without overt coronary artery disease.

RESULTS

There were no significant differences in perioperative death, myocardial infarction or stroke between subgroups at 30 days after operation. The 5- and 10-year Kaplan-Meier survival rate after operation was 77% and 51% in those without and 54% and 24% in those with overt coronary artery disease (p < 0.001), respectively. For both groups, survival was significantly poorer than that expected for an age- and gender-matched group. Patients undergoing aortoiliac surgery were more likely to be alive at 10 years than those undergoing femoropopliteal surgery (47% vs. 28%, p = 0.001). The 5-year cumulative incidence of cardiac events was greater in those with overt coronary artery disease (50% vs. 28%, p = 0.003). In multivariable analysis, age, coronary artery disease and diabetes were independent predictors of death.

CONCLUSIONS

Coronary events are the most important cause of long-term morbidity and mortality after peripheral vascular surgery. Patients without overt coronary artery disease are at significant risk for long-term cardiac events.

Eosinophiluria in atheroembolic renal disease

PURPOSE AND PATIENTS

Eosinophiluria has been reported in acute interstitial nephritis and other renal diseases, but its presence in atheroembolic renal disease (AERD) has not been previously established. AERD has been identified as a cause of acute and chronic renal failure, particularly in elderly patients with advanced atherosclerosis and in those patients who have undergone manipulation or intervention of the abdominal aorta, renal artery, or coronary artery. The definitive diagnosis is made by renal biopsy. However, many patients are too acutely ill to tolerate renal biopsy and, in recent years, peripheral eosinophilia, hypocomplementemia, and thrombocytopenia have been recognized in association with AERD. Previous studies have reported that AERD is associated with an inactive renal sediment and an absence of urine eosinophils. We reviewed our experience over a 4-year period with 24 patients with renal biopsy-proven AERD.

RESULTS

Urine eosinophils were evaluated in nine patients to help determine the cause of their renal deterioration. Seven of these patients presented with evidence of vascular disease. Three patients had procedures involving manipulation of the abdominal aorta. Physical examination revealed findings of atheroembolism in three of nine patients. Overall, eight of nine patients had a positive Hansel's stain for eosinophiluria. Six of eight patients had more than 5% of their urinary white cell count as eosinophils. The reason for failure of previous studies to detect eosinophiluria in AERD is unclear but may have been related to the use of Wright's stain instead of Hansel's stain.

CONCLUSION

In the evaluation of acute renal insufficiency, eosinophiluria may indicate AERD in addition to the other known causes for this finding.