Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology 2023 Focused Update of the Guidelines for the Use of Antiplatelet Therapy

Antiplatelet therapy (APT) is the foundation of treatment and prevention of atherothrombotic events in patients with atherosclerotic cardiovascular disease. Selecting the optimal APT strategies to reduce major adverse cardiovascular events, while balancing bleeding risk, requires ongoing review of clinical trials. Appended, the focused update of the Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology guidelines for the use of APT provides recommendations on the following topics: (1) use of acetylsalicylic acid in primary prevention of atherosclerotic cardiovascular disease; (2) dual APT (DAPT) duration after percutaneous coronary intervention (PCI) in patients at high bleeding risk; (3) potent DAPT (P2Y12 inhibitor) choice in patients who present with an acute coronary syndrome (ACS) and possible DAPT de-escalation strategies after PCI; (4) choice and duration of DAPT in ACS patients who are medically treated without revascularization; (5) pretreatment with DAPT (P2Y12 inhibitor) before elective or nonelective coronary angiography; (6) perioperative and longer-term APT management in patients who require coronary artery bypass grafting surgery; and (7) use of APT in patients with atrial fibrillation who require oral anticoagulation after PCI or medically managed ACS. These recommendations are all on the basis of systematic reviews and meta-analyses conducted as part of the development of these guidelines, provided in the Supplementary Material.

The COVID conversations: A content analysis of Canadian pharmacy organizations' communication of pharmacists' roles and services during the COVID-19 pandemic

Background

The COVID-19 pandemic presented a unique challenge for pharmacists as they navigated information scarcity on the frontlines while being identified as information experts. Alberta pharmacists looked to their professional organizations for direction regarding what their roles should be in a crisis. The objective of this study was to explore pharmacists' roles and services and how they were communicated by pharmacy organizations during the first year of the COVID-19 pandemic.

Methods

The study used a conventional content analysis method to explore the online communication of relevant pharmacy organizations for Alberta pharmacists. Five organization websites (National Association of Pharmacy Regulatory Authorities, Canadian Pharmacists Association [CPhA], Canadian Society of Hospital Pharmacists [CSHP], Alberta College of Pharmacy [ACP] and the Alberta Pharmacists' Association [RxA]) were examined to identify and catalogue publicly accessible documents that communicated pharmacists' roles and services during the first year of the pandemic for Alberta pharmacists.

Results

A total of 92 documents were collected from CPhA (60), CSHP (2), ACP (26) and RxA (4). While most documents communicated information about pharmacists' roles in public health, patient care and drug and personal protective equipment supply, more than one-third of the documents (32/92, 34.8%) required contextual information to interpret the communication. There was an observed shift in the communication after the first 6 months, becoming more direct in its messaging and context.

Conclusion

These pharmacy organizations communicated information for pharmacists' roles and services to provide direction and guidance in the ever-changing context of the COVID-19 pandemic for Alberta pharmacists. Their communication became clearer and more direct as the pandemic progressed, requiring less inference to understand the intended message.

The problem with predictions - A cautionary tale of empirically adjusting apixaban dosing with carbamazepine

Concomitant use of apixaban and carbamazepine (CBZ) is not recommended due to an anticipated reduction in apixaban concentration, although few case reports describe this interaction. We report a case of initiating apixaban 10 mg twice daily (BID), in a patient stabilized on CBZ 600 mg BID that was guided by prior experience. Apixaban concentrations were substantially elevated with initial empiric dosing; apixaban dosing of 7.5 mg BID was eventually implemented. This case highlights the fact that the degree of induction by CBZ can vary, regardless of the dose, and requires clinicians to be cautious when applying prior experiences with patients to new patients.

The Role of Direct Oral Anticoagulants in Patients With Coronary Artery Disease

Despite contemporary management, patients with coronary artery disease (CAD) remain at high risk for thrombotic events. Several randomized controlled trials have evaluated the use of direct oral anticoagulants (DOACs) in patients with CAD, including in the setting of acute coronary syndrome (ACS) and stable CAD, and in patients with concomitant atrial fibrillation. Trials of apixaban and dabigatran in patients with ACS demonstrate no benefit with an increased risk of bleeding. Conversely, rivaroxaban at a reduced dose of 2.5 mg twice daily reduced thrombotic events and all-cause mortality when added to dual antiplatelet therapy in patients with ACS. Similarly, the addition of low-dose rivaroxaban to acetylsalicylic acid reduced the risk of thrombotic events in patients with stable CAD. However, the addition of a DOAC to antiplatelet therapy increased the risk of major bleeding. In patients with atrial fibrillation undergoing percutaneous coronary intervention, dual-pathway or low-dose triple therapy regimens including dabigatran or rivaroxaban reduced bleeding risk compared to traditional warfarin-based triple therapy, although it remains unclear whether these regimens preserve antithrombotic efficacy. DOAC-based antithrombotic regimens prove useful in patients with CAD in various settings; however, careful selection of patients and regimens per trial protocols are critical to achieving net benefit.

2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Focused Update of the Guidelines for the Use of Antiplatelet Therapy

Antiplatelet therapy (APT) has become an important tool in the treatment and prevention of atherosclerotic events, particularly those associated with coronary artery disease. A large evidence base has evolved regarding the relationship between APT prescription in various clinical contexts and risk/benefit relationships. The Guidelines Committee of the Canadian Cardiovascular Society and Canadian Association of Interventional Cardiology publishes regular updates of its recommendations, taking into consideration the most recent clinical evidence. The present update to the 2011 and 2013 Canadian Cardiovascular Society APT guidelines incorporates new evidence on how to optimize APT use, particularly in situations in which few to no data were previously available. The recommendations update focuses on the following primary topics: (1) the duration of dual APT (DAPT) in patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome and non-acute coronary syndrome indications; (2) management of DAPT in patients who undergo noncardiac surgery; (3) management of DAPT in patients who undergo elective and semiurgent coronary artery bypass graft surgery; (4) when and how to switch between different oral antiplatelet therapies; and (5) management of antiplatelet and anticoagulant therapy in patients who undergo PCI. For PCI patients, we specifically analyze the particular considerations in patients with atrial fibrillation, mechanical or bioprosthetic valves (including transcatheter aortic valve replacement), venous thromboembolic disease, and established left ventricular thrombus or possible left ventricular thrombus with reduced ejection fraction after ST-segment elevation myocardial infarction. In addition to specific recommendations, we provide values and preferences and practical tips to aid the practicing clinician in the day to day use of these important agents.

Anticoagulant and Antiplatelet Prescribing Patterns for Patients with Atrial Fibrillation after Percutaneous Coronary Intervention

BACKGROUND

Current guidelines recommend triple antithrombotic therapy (TAT), defined as acetylsalicylic acid (ASA), clopidogrel, and warfarin, for patients with nonvalvular atrial fibrillation who have undergone percutaneous coronary intervention with stent implantation. The choice of anticoagulant/antiplatelet therapy in this population is ambiguous and complex, and prescribing patterns are not well documented.

OBJECTIVE

To characterize local prescribing patterns for anticoagulant/antiplatelet therapy after percutaneous coronary intervention in patients with nonvalvular atrial fibrillation.

METHODS

A chart review was conducted at a single quaternary cardiology centre. Patients with nonvalvular atrial fibrillation were identified via medical records, and those who underwent percutaneous coronary intervention were identified using a local clinical patient registry. Adult inpatients with nonvalvular atrial fibrillation and a CHADS2 score (based on congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke) of 1 or higher who underwent percutaneous coronary intervention from 2011 to 2013 were included. Patients undergoing cardiovascular surgery or transcatheter aortic valve replacement, those with mechanical devices requiring anticoagulation, and those with an allergy to any component of TAT were excluded.

RESULTS

Seventy patients were included. The median age was 75 years, and 52 (74%) were men. At discharge, 30 (43%) were receiving TAT and 27 (39%) were receiving dual antiplatelet therapy (clopidogrel and ASA). No patients received the combination of warfarin and clopidogrel. Among those who received TAT, 90% (19 of 21) who received a bare metal stent had a recommended duration of 1 month, and 75% (6 of 8) who received a drug-eluting stent had a recommended duration of 1 year. Direct-acting oral anticoagulants with 2 antiplatelet drugs were prescribed for 9% (6 of 70) of the patients, and 10% (7 of 70) received ticagrelor and ASA with or without warfarin. Overall, the combination of ASA, oral anticoagulant, and P2Y12 inhibitor was used for 54% (38/70) of the patients.

CONCLUSIONS

Fewer than half of the patients in this study received TAT, and almost 20% received non-evidence-based therapy with a direct-acting oral anticoagulant or ticagrelor, alone or in combination. Despite current guideline recommendations, the rate of TAT utilization was lower than rates reported in the literature.

Drug Interactions Between Antiplatelet or Novel Oral Anticoagulant Medications and Antiretroviral Medications

Objective: To review potential drug interactions between antiretroviral (ARV) medications and antiplatelets or novel oral anticoagulants (NOACs). Data Sources: A literature search of MEDLINE, PubMed, EMBASE, International Pharmaceutical Abstracts, and Google Scholar was performed using the search terms (1) clopidogrel or ticagrelor or prasugrel, (2) dabigatran or rivaroxaban or apixaban, and (3) antiretrovirals. Study Selection and Data Extraction: Any English language study or case report describing a drug interaction between an ARV and an antiplatelet or NOAC was included. Additional information was taken from pharmacokinetic studies of individual agents alone or information from similar drug interactions. Results: Two studies were identified through the literature search: one reporting an in vivo interaction between ritonavir and prasugrel and the other an in vitro interaction between efavirenz and clopidogrel. A case report describing a drug interaction between nevirapine and rivaroxaban was also located. Information from pharmacokinetic studies and from similar drug interactions allowed for a comprehensive review of potential drug interactions. Conclusions: There are potential drug interactions between ARVs, antiplatelet agents or NOACs. Management of these interactions may include selecting ARVs with a lower potential for drug interactions or choosing antiplatelet agents or NOACs least likely to interact with ARVs. With protease inhibitors or cobicistat, clopidogrel and dabigatran do not appear to have clinically significant interactions. Nonnucleoside reverse transcriptase inhibitors have a low potential for interactions with prasugrel and dabigatran. Clinically significant drug interactions are unlikely to occur between antiplatelet agents or NOACs and nucleoside reverse transcriptase inhibitors raltegravir, dolutegravir, or maraviroc.

Developing Preceptors through Virtual Communities and Networks: Experiences from a Pilot Project

BACKGROUND

Supporting preceptors is critical to the expansion of experiential learning opportunities for the pharmacy profession. Informal learning opportunities within communities of practitioners are important for hospital preceptors. However, such communities may be limited by geographic separation of preceptors from peers, faculty members, and supports within the pharmacy services department.

OBJECTIVE

To use computer-mediated conferencing to create a sense of community among preceptors, specifically by using this medium to provide initial development of and continuing support for preceptors, and to examine preceptors' satisfaction with this approach.

METHODS

Thirty-nine preceptors who had completed a day-long face-to-face preceptor development workshop and who were supervising students in 1 of 2 specific rotation blocks were invited to participate in the study. The pharmacists used computer-mediated conferencing to meet for virtual networking about specific topics. They met once before the student rotation to receive instructions about the technology and to discuss student orientation and scheduling, and 3 times during the student rotation for open discussion of specific topics. Evaluation and feedback were solicited by means of an electronic survey and virtual (i.e., computer-based) feedback sessions with an independent facilitator.

RESULTS

The response rate was 66% (26/39) for the electronic survey, but only 15% (6/39) for the virtual feedback sessions. All of the respondents were experienced preceptors, but for 92% (22/24), this was their first experience with computer-mediated conferencing. Overall, the sessions had a positive reception, and participants found it useful to share information and experiences with other preceptors. The main challenges were related to the technology, perceived lack of support for their participation in the sessions, and inconvenience related to the timing of sessions.

CONCLUSION

Computer-mediated conferencing allowed preceptors to learn from and to support each other despite geographic distance. The participants felt that these sessions encouraged them to serve as preceptors regularly. Such encouragement could contribute to the retention of preceptors, which is important to the expansion of experiential learning.

The prevalence of natural health product use in patients with acute cardiovascular disease

BACKGROUND

Natural health products (NHP) use may have implications with respect to adverse effects, drug interactions and adherence yet the prevalence of NHP use by patients with acute cardiovascular disease and the best method to ascertain this information is unknown.

OBJECTIVE

To identify the best method to ascertain information on NHP, and the prevalence of use in a population with acute cardiovascular disease.

METHODS

Structured interviews were conducted with a convenience sample of consecutive patients admitted with acute cardiovascular disease to the University of Alberta Hospital during January 2009. NHP use was explored using structured and open-ended questions based on Health Canada's definition of NHP. The medical record was reviewed, and documentation of NHP use by physicians, nurses, and pharmacists, compared against the gold-standard structured interview.

RESULTS

88 patients were interviewed (mean age 62 years, standard deviation [SD 14]; 80% male; 41% admitted for acute coronary syndromes). Common co-morbidities included hypertension (59%), diabetes (26%) and renal impairment (19%). NHP use was common (78% of patients) and 75% of NHP users reported daily use. The category of NHP most commonly used was vitamins and minerals (73%) followed by herbal products (20%), traditional medicines including Chinese medicines (9%), homeopathic preparations (1%) and other products including amino acids, essential fatty acids and probiotics (35%). In a multivariable model, only older age was associated with increased NHP use (OR 1.5 per age decile [95%CI 1.03 to 2.2]). When compared to the interview, the highest rate of NHP documentation was the pharmacist history (41%). NHP were documented in 22% of patients by the physician and 19% by the nurse.

CONCLUSIONS

NHP use is common in patients admitted with acute cardiovascular disease. However, health professionals do not commonly identify NHP as part of the medication profile despite its potential importance. Structured interview appears to be the best method to accurately identify patient use of NHP.

Impact of tobacco smoking cessation on stable clozapine or olanzapine treatment

OBJECTIVE

To examine the pharmacokinetic implications and potential clinical effects of tobacco smoking cessation in patients on stable clozapine or olanzapine treatment.

DATA SOURCES

A literature search of MEDLINE (1950-November 2009) and EMBASE (1980-November 2009) was conducted using the search terms smoking, tobacco, cigarette, cannabis, smoking cessation, cytochrome P450, antipsychotic, clozapine, and olanzapine. In addition, reference lists from publications identified were searched manually.

STUDY SELECTION AND DATA EXTRACTION

English-language articles and human studies were identified, yielding 111 returns. Articles that reported clinical outcomes following smoking cessation were selected. Pharmacokinetic data for these drugs were reviewed and articles that provided relevant background information were also included.

DATA SYNTHESIS

Pharmacokinetic studies have demonstrated more rapid clearance of olanzapine and lower clozapine and norclozapine (desmethylclozapine) concentrations in smokers compared to nonsmokers. These studies also found that smokers require higher doses of these agents than nonsmokers. There are case reports of adverse clinical outcomes following smoking cessation in patients being treated with olanzapine and clozapine. Reports that included serum concentrations consistently found elevations following smoking cessation, and dosage reductions of 30-40% were required to achieve pre-cessation concentrations. Worsening psychiatric symptoms, somnolence, hypersalivation, extreme fatigue, extrapyramidal effects, and seizures have all been reported following smoking cessation in this patient group.

CONCLUSIONS

Pharmacists need to be aware of potential risks associated with smoking cessation in patients stabilized on clozapine or olanzapine. Toxicity as a result of recent smoking reduction or cessation may be a reason for hospital admission. For hospitalized patients, pharmacists should obtain information concerning smoking status, including cessation attempts. Nonspecific signs and symptoms of elevated clozapine or olanzapine concentrations should be considered in relation to clinical status while the patient is hospitalized. Measurement of baseline serum clozapine concentrations and/or empiric dosage adjustment in patients expected to have a prolonged hospital stay with forced smoking cessation may be appropriate.

Single Antiplatelet Therapy for Patients with Previous Gastrointestinal Bleeds

Objective:

To determine whether aspirin plus a proton pump inhibitor (PPI) is preferable, from a gastrointestinal bleed (GIB) risk perspective, to clopidogrel in patients who have experienced a GIB while on aspirin and who require single antiplatelet therapy for secondary prevention of cardiovascular disease.

Data Sources:

A literature search was conducted using EMBASE (1980–January 2008), PubMed (1966–January 2008), Google, and a manual search of the reference lists using the search terms gastrointestinal bleed, gastrointestinal hemorrhage, peptic ulcer hemorrhage, ASA, aspirin. Plavix, clopidogrel, and PPI. The search, limited to human and English studies, yielded 110 returns.

Study Selection and Data Extraction:

Randomized trials that compared aspirin with clopidogrel, involved patients who had previously experienced a GIB, and provided detailed information on the type and dose of drugs used were included. Studies were required to provide information on the recurrence of GIB.

Data Synthesis:

Two randomized trials were reviewed to assess the safety of secondary prevention of cardiovascular disease with respect to previous GIB. These noninferiority trials compared aspirin plus a PPI with clopidogrel over 12 months following confirmed healing of an aspirin-induced ulcer. In both trials, the majority of the GIB recurrences were in the clopidogrel group (8.6% vs 0.7%; difference 7.9%; 95% CI 3.4 to 12.4; p = 0.001 and 13.6% vs 0%; difference 13.6%; 95% CI 6.3 to 20.9; p = 0.0019) and the difference in recurrence rates exceeded the a priori selected upper boundary.

Conclusions:

Findings reported in the limited literature available support that clopidogrel is not equivalent to the combination of aspirin plus a PPI in the patient population studied. Aspirin plus a PPI would be considered clinically superior and should be used in medically managed patients who require single antiplatelet therapy but have had a prior GIB while on aspirin. Further research regarding dual antiplatelet therapy and a PPI is required.

Effect of a prior authorization process on antiplatelet therapy and outcomes in patients prescribed clopidogrel following coronary stenting

BACKGROUND

Alberta Blue Cross (ABC) provides copayment-based coverage for residents older than 65 years. A prior authorization (PA) process for patients prescribed clopidogrel following stent insertion was changed to an authorized prescriber (AP) list process in March 2002.

OBJECTIVE

To determine the effect of a policy change in medication coverage for clopidogrel on patients' filling of prescriptions and outcomes following stent insertion.

METHODS

Consecutive patients who received a coronary stent between September 1, 2001, and August 31, 2002, at the University of Alberta Hospital and were eligible for ABC coverage were identified. Data were obtained from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and ABC databases.

RESULTS

One hundred twelve patients (45 in the PA period and 67 in the AP period) who received a coronary stent were eligible for ABC coverage during the study period. The two cohorts of patients were similar with respect to demographics. Fewer patients in the PA period than in the AP period had their prescription filled on the day of discharge (31% versus 54%; P=0.02), and the median time to fill was four days versus zero days in the PA and AP periods, respectively (Wilcoxon P=0.04). There was no significant difference in the proportion of patients filling their prescriptions after 28 days from discharge (67% versus 75%, P = not significant) or in the overall comparison of time to fill (log rank P=0.22). Two repeat revascularization procedures were necessary within six weeks after stent placement; both were in PA period patients who delayed or failed to fill their prescription.

CONCLUSIONS

The PA process may have delayed patients filling clopidogrel prescriptions following hospital discharge and has the potential to contribute to negative clinical consequences.

Use of OTC and herbal products in patients with cardiovascular disease

BACKGROUND

The use of nonprescription and herbal products by the public is rising, resulting in an increased potential for adverse reactions or drug interactions in cardiac patients.

OBJECTIVE

To describe the utilization patterns for nonprescription medications and herbal products in patients with cardiovascular disease across Canada.

METHODS

Patients admitted to 8 teaching hospitals during the winter of 1998/1999 were interviewed by a pharmacist using a structured survey instrument.

RESULTS

Interviews were conducted with 306 patients (mean age 66 y; 60% men). The majority (74%) had coronary artery disease; however, hypertension, congestive heart failure, and arrhythmias were also common. The most common product categories used were pain relievers (51%), single-entity vitamin/mineral (38%), multivitamin/mineral (23%), antacids (21%), laxatives (17%), and herbals (17%). As compared with western (28%) and central Canada (26%), fewer patients in the Atlantic region (11%) reported daily use of multivitamin/mineral products. Overall, the usage of specific single-entity vitamin/mineral products was most commonly vitamin E (24%), vitamin C (16%), calcium (9%), and B vitamins (8%). Central Canada reported the highest rates (25%) of daily or weekly use of herbal products. The most common herbal products used were garlic (13%), cayenne pepper (2%), and ginseng (2%). More than half of the patients consulted with their pharmacist at least occasionally regarding the use of these products.

CONCLUSIONS

Canadian patients with cardiovascular disease commonly report the use of herbal products and vitamins. Allied health professionals need to be aware of the widespread use of these products and their potential for adverse reactions and drug interactions.

A randomized trial of the effect of community pharmacist intervention on cholesterol risk management: the Study of Cardiovascular Risk Intervention by Pharmacists (SCRIP)

BACKGROUND

Despite clear evidence for the efficacy of lowering cholesterol levels, there is a deficiency in its real-world application. There is a need to explore alternative strategies to address this important public health problem. This study aimed to determine the effect of a program of community pharmacist intervention on the process of cholesterol risk management in patients at high risk for cardiovascular events.

METHODS

A randomized controlled trial conducted in 54 community pharmacies (1998-2000) included patients at high risk for cardiovascular events (with atherosclerotic disease or diabetes mellitus with another risk factor). Patients randomized to pharmacist intervention received education and a brochure on risk factors, point-of-care cholesterol measurement, referral to their physician, and regular follow-up for 16 weeks. Pharmacists faxed a simple form to the primary care physician identifying risk factors and any suggestions. Usual care patients received the same brochure and general advice only, with minimal follow-up. The primary end point was a composite of performance of a fasting cholesterol panel by the physician or addition or increase in dose of cholesterol-lowering medication.

RESULTS

The external monitoring committee recommended early study termination owing to benefit. Of the 675 patients enrolled, approximately 40% were women, and the average age was 64 years. The primary end point was reached in 57% of intervention patients vs 31% in usual care (odds ratio, 3.0; 95% confidence interval, 2.2-4.1; P<.001).

CONCLUSIONS

A community-based intervention program improved the process of cholesterol management in high-risk patients. This program demonstrates the value of community pharmacists working in collaboration with patients and physicians.

Effects of the 1994 Canadian Cardiovascular Society clinical practice guidelines for congestive heart failure

BACKGROUND

In 1994, the Canadian Cardiovascular Society (CCS) issued practice guidelines for the management of congestive heart failure (CHF), which strongly recommended the use of angiotensin-converting enzyme (ACE) inhibitors.

OBJECTIVE

To compare a strategy of active implementation of the CCS guidelines for CHF with the usual passive approach on the use of ACE inhibitors in hospitalized patients with CHF.

PATIENTS AND METHODS

The study was conducted in eight Canadian hospitals close to the time of release of the CCS guidelines for CHF in the summer of 1994. The patients comprised those who were admitted to the participating hospitals with a diagnosis of CHF during the study period. Active dissemination included stakeholder development of pocket cards outlining an algorithm for the management of CHF based on the CCS guidelines and was conducted at the two Edmonton, Alberta hospitals. The cards were widely disseminated in conjunction with a series of workshops and presentations. Passive dissemination occurred at six other hospitals, and involved only the distribution of the CCS guidelines in the usual fashion (with no structured dissemination program). The primary outcome measured was the use of ACE inhibitors in the six- to 12-month period before the release of the CCS guidelines, compared with after the release in the active and passive groups.

RESULTS

In the active group, hospital records of 1170 patients with CHF were reviewed before, and 1279 were reviewed after, the release of the CCS guidelines. In the passive group, 3436 were reviewed before, and 1912 were reviewed after the release of the guidelines. ACE inhibitor use did not change significantly in the active group (52.4% before versus 50.9% after) or in the passive group (53.4% before versus 56.5% after).

CONCLUSIONS

Neither the active nor passive approaches to the dissemination of the CCS guidelines for CHF had any impact on the use of ACE inhibitors in hospitalized patients with CHF. Further efforts to package, deliver and evaluate guidelines are needed.

Levels of evidence in cardiovascular clinical practice guidelines

BACKGROUND

Clinical practice guidelines (CPGs) can be helpful in distilling the medical research literature for clinicians; however, the guidelines should acknowledge the variable methodological quality used in clinical research by tempering their recommendations with a 'levels of evidence' scale.

OBJECTIVE

To evaluate the proportion of English-language cardiovascular CPGs that provide the user with recommendations graded according to a defined levels of evidence scale. In addition, to evaluate other key aspects important in the critical appraisal of CPGs.

METHODS

CPGs for atrial fibrillation, congestive heart failure and myocardial infarction were identified by searching MEDLINE, a reference text of CPGs and the Internet. Each CPG was evaluated using a priori-defined criteria based on the Evidence-Based Medicine Working Group's paper on critical appraisal of CPGs, including use of a reproducible search strategy, method of obtaining consensus, peer review and testing in practice.

RESULTS

A total of 95 CPGs were evaluated. Only 13% graded their recommendations using a defined levels of evidence scale. In addition, few CPGs documented a reproducible search strategy or peer review process, and none had been formally tested in practice.

CONCLUSIONS

Reporting the levels of evidence for recommendations is an important component of CPGs, yet this system is not widely used.

Adequacy of anticoagulation in patients with atrial fibrillation coming to a hospital

STUDY OBJECTIVE

To evaluate the adequacy of anticoagulation in patients with atrial fibrillation (AF) coming to a hospital.

DESIGN

Retrospective medical record review.

SETTING

Tertiary care hospital.

PATIENTS

Consecutive patients with a history of AF who had been prescribed warfarin and who had the international normalized ratio (INR) measured when they arrived at the hospital. Those who developed AF as a complication during hospitalization were excluded.

MEASUREMENTS AND MAIN RESULTS

Of 1085 patients, 375 (mean age 73 yrs, 56.3% men) were eligible for further evaluation. Most had nonvalvular AF; in 44.5% the INR was subtherapeutic, in 36.5% it was therapeutic, and in 18.9% it was supratherapeutic. Patients admitted for any thromboembolic event and for ischemic stroke were significantly more likely to have subtherapeutic INRs.

CONCLUSION

It is well documented in the literature that warfarin is underprescribed, but our results suggest that even in treated patients, about half are inadequately protected from thromboembolism.

Study of Cardiovascular Risk Intervention by Pharmacists (SCRIP): a randomized trial design of the effect of a community pharmacist intervention program on serum cholesterol risk

OBJECTIVE

To determine the efficacy of a program of intervention by pharmacists on lipid risk management in patients at high risk for cardiovascular events.

METHODS

Randomized, multicenter (44 sites in Alberta and Saskatchewan) study of community pharmacist intervention versus usual care in 1000 patients. Patients are those at high risk of vascular events (existing atherosclerotic vascular disease, or diabetes with > or = 1 other risk factor). After obtaining consent, the pharmacist calls the Project Office to randomize. Patients allocated to intervention receive a brochure and education about cardiovascular risk factors. Pharmacists also complete a physician contact form, which lists the patient's risk factors, medications, and any recommendations. A point-of-care cholesterol test is performed, the result is discussed with the patient, and it is entered on the contact form. If appropriate, the patient is asked to see his or her primary care physician for further assessment and/or treatment, and the form is faxed to the physician. Patients are followed up at two, four, eight, 12, and 16 weeks. During follow-up visits, pharmacists provide educational reinforcement and check for primary end point occurrence. Patients allocated to usual care receive the brochure only, with minimal follow-up. The primary end point is a composite of measurement of a complete lipid panel by the physician, or addition or modification of lipid-lowering drug therapy. Substudies will evaluate economics (third-party payer and pharmacy manager perspective), patient satisfaction, and quality of life.

CONCLUSIONS

SCRIP (Study of Cardiovascular Risk Intervention by Pharmacists) is a unique ongoing trial that is evaluating a community pharmacist intervention designed to optimize cholesterol risk management in patients at high risk for cardiovascular events.

The treatment and prevention of coronary heart disease in Canada: do older patients receive efficacious therapies? The Clinical Quality Improvement Network (CQIN) Investigators

OBJECTIVES

To review the evidence for clinical efficacy and cost-effectiveness of proven medications in the treatment and prevention of myocardial infarction (MI) in older patients; to summarize Canadian data on treatment patterns and clinical outcomes for younger and older patients with coronary heart disease; to explore the reasons for gaps between best care, based on the evidence of efficacy from trials, and usual care, based on the population effectiveness audits; and to explore potential approaches to closing the care gaps.

DESIGN

Review of the recent clinical trial literature on the management of MI, highlighting results in older patients. Review of medication utilization and outcomes data from a series of large, consecutively enrolled patient cohorts with acute MI (N = 7070) in a variety of cardiac care settings (10 centers in five Canadian provinces, including university-based teaching hospitals, community hospitals, cardiologist and family physician out-patient clinics) from 1987 to 1996.

RESULTS

There is no qualitative interaction of cardiac therapies: thrombolytics, beta-blockers, acetylsalicylic acid (ASA), and statins are efficacious in all clinically relevant patient subgroups, including older people. However, there are consistent gaps between usual care and best care, particularly among older patients (in whom there is also a concomitantly higher mortality risk). Repeated multivariate analyses confirm older age to be an independent contributor to increased risk. Use of efficacious medications is, in contrast, consistently associated with increased survival. Analysis of temporal trends suggests beneficial changes in practice patterns and outcomes are possible to achieve. However, "best care" has not been rapidly or completely achieved. Review of strategies to close these care gaps suggests that audit and feedback, critical pathways, and multifactorial interventions involving patients and other members of the healthcare team as well as physicians may be the most efficacious strategies for change.

CONCLUSIONS

Despite equal or enhanced efficacy, there is consistently less prescription of proven drugs among older cardiac patients. These care patterns may contribute to their enhanced risk. The causes underlying these practice patterns are complex, and their population impact may be undervalued by clinicians and managers. Improvement of these patterns is difficult, but ultimately it would be beneficial for this presently disadvantaged, readily identified, high risk patient population.

Use of nonprescription medications by patients with congestive heart failure

OBJECTIVE

To define the utilization pattern of nonprescription therapies in patients with congestive heart failure (CHF) and to compare this pattern with that of an age- and gender-matched control group without any self-reported heart conditions.

DESIGN

Survey questionnaire completed by participants at home.

SETTING

Ambulatory CHF clinic in a tertiary care hospital.

SUBJECTS

Patients attending the clinic between July 1995 and May 1996 who agreed to participate. Control subjects were age- and gender-matched participants identified and approached by participating patients.

OUTCOME MEASURES

Nonprescription therapies used at least once weekly.

RESULTS

Completed questionnaires were received from 180 (75%) of the 239 patients who agreed to participate and from 133 controls. Mean age of responding patients was 69 years (63% men). Controls were younger, with a mean age of 64 years (63% men). The most commonly used nonprescription medication categories for both patients and controls, with no significant intergroup differences, were vitamins and minerals (59% patients, 50% controls), pain relievers (48% and 43%, respectively), herbal or health food products (38% and 38%), antacids (26% and 28%), and laxatives (24% and 21%). Significantly fewer patients than controls used cough and cold products (9% vs. 17%; p < 0.05), specifically oral decongestants (0.6% vs. 5%; p < 0.01), and more patients than controls used nutritional supplements (17% vs. 4%; p < 0.01).

CONCLUSIONS

Overall, use of nonprescription therapies by our CHF clinic patients is similar to that of an age- and gender-matched population without a self-reported heart condition. The differences in medication use observed between patients and controls included cough and cold products that might be harmful. This likely reflects appropriate caution with which CHF patients approach nonprescription therapies.

Contemporary utilization of digoxin in patients with atrial fibrillation. Clinical Quality Improvement Network Investigators

OBJECTIVE

To define the contemporary practice patterns of digoxin utilization for the management of patients with atrial fibrillation (AF).

METHODS

A retrospective medical records audit of 2490 patients with documented AF, from 12 Canadian hospitals and six outpatient clinics, during fiscal year 1993-1994, was conducted.

RESULTS

There were 1158 women and 1332 men, with a mean age of 72 years; 956 patients were < 70 years of age and 1534 were > or = 70 years old. The majority of patients had nonvalvular AF (75% of those with a documented etiology). Paroxysmal AF (PAF) was documented in 800 patients, 936 had chronic AF, and 754 had new-onset AF. While the prescribing patterns were heterogeneous, the predominant strategy pursued in all subgroups appeared to be that of achieving rate control. Digoxin was the most commonly prescribed medication (79%) and was prescribed for the majority of patients in all subgroups, including patients with PAF (74%) and patients with a history of chronic AF who were currently in sinus rhythm (83%). Only 10% of the patients with PAF who were prescribed digoxin had congestive heart failure. Similarly, less than 25% of the patients with chronic AF who were prescribed digoxin after conversion to sinus rhythm had evidence of heart failure.

CONCLUSIONS

In the absence of clinical trial evidence supporting either a strategy of antiarrhythmic therapy or rate control with anticoagulation, the appropriateness of the observed prescribing practices cannot be judged. However, digoxin is not the best rate-controlling agent for all patients and may be overused in certain subgroups of patients, such as those with PAF and those successfully converted to sinus rhythm.

Cause-specific noncardiac mortality in patients with congestive heart failure--a contemporary Canadian audit. Clinical Quality Improvement Network (CQIN) Investigators

BACKGROUND

Noncardiac mortality in congestive heart failure (CHF) is substantial.

OBJECTIVE

To define the specific causes of noncardiac mortality among hospitalized CHF patients.

DESIGN

Retrospective medical record audit.

SETTING

Three hospitals in British Columbia and Alberta, 1992-93.

PATIENTS

A total of 2216 consecutive patients admitted with CHF.

MAIN RESULTS

The overall mortality rate was 404 of 2216 (18%). Cause of death was cardiac in 290 of 404 (72%) patients, with an average age of 76 years. However, 114 of 404 (28%) deaths, in patients with an average age of 69 years, had noncardiac causes. Four causes accounted for almost 70%, of the noncardiac deaths: cancer (24%); pneumonia (16%); other pulmonary diseases, including embolism (15%); and cerebrovascular disease (11%). Renal disease (9%), gastrointestinal disorders (9%), non-pulmonic sepsis (7%), multiple system failure (5%) and trauma or surgical complications (4%) accounted for most of the remaining noncardiac deaths.

CONCLUSIONS

Noncardiac causes produce a substantial proportion of deaths among elderly and sick CHF patients. As the survival of patients with CHF improves, the relative risk of noncardiac mortality in this population will likely increase. However, since hospitalized CHF patients so closely reflect their general population counterparts in terms of cause-specific mortality risk, the search for an ideal therapy might be viewed as a quixotic search for the cure of death.