BC Guidelines

Asthma Diagnosis, Education, and Management (2023) provides recommendations for the diagnosis, education, and management of mild – moderate asthma in the primary care setting, for both pediatric and adult patients. It replaces two previous BC Guidelines, Asthma in Adults (2015) and Asthma in Children (2015).

Key Recommendations include:

• A positive response to a therapeutic trial of salbutamol following an office visit in which the patient presents with audible wheeze is sufficient for a presumptive diagnosis under age 6.
• Confirmation with spirometry remains the gold standard for patients over 6.
• Reassess asthma control and exacerbation risk at least every 6 months and decrease medication doses to the lowest effective dose.
• Consider lower-environmental impact medication options where appropriate as metered-dose inhalers (MDIs) contribute disproportionately to climate change, which in turn can affect asthma.

Atrial Fibrillation - Diagnosis and Management (2023) provides recommendations for the diagnosis and management of atrial fibrillation (AF) including the primary prevention of stroke and systemic embolism in adults aged ≥ 19 years. It also covers the management of AF in the acute care and outpatient office settings. Management of atrial flutter (AFL) is also included.

Key Recommendations include:

• Opportunistic screening for AF (pulse check for 20 seconds) in people ≥ 65 years is recommended.
• Treat all patients with valvular AF (mechanical valve or moderate to severe mitral stenosis) with warfarin (direct oral anticoagulants [DOACs] should not be used).
• Use the Canadian Cardiovascular Society (CCS) Algorithm (“CHADS-65”) in all patients with non-valvular AF to determine the need for stroke prevention therapy. • DOACs are recommended in patients age ≥ 65 years or with CHADS2 score ≥ 1 who have non-valvular AF.
• Rhythm control is preferred as the initial treatment strategy in patients with recently diagnosed AF (within a year) because it is associated with reduced cardiovascular death and reduced rates of stroke.
• Long-term oral antiarrhythmic therapy should not be continued in patients when AF becomes permanent.
• Patients with AFL should be stratified and managed in the same manner as those with AF, except that catheter ablation is preferred over pharmacotherapy for rate/rhythm control.
• Manage contributory comorbidities, such as hypertension, diabetes, and heart failure.
• Use the CCS Symptoms of Atrial Fibrillation (CCS-SAF) score to help triage patients with Class 3 or 4 severity for specialist care.
• Use of i.v. β-blockers, diltiazem, verapamil, digoxin, and amiodarone are contraindicated for acute management of pre-excitation AF (e.g., Wolff-Parkinson-White) because of the potential to precipitate a life-threatening arrhythmia. 

Heart Failure - Diagnosis and Management (2023) provides recommendations for the diagnosis and management of people aged ≥ 19 years with suspected or confirmed heart failure in the ambulatory primary care setting. Given that heart failure is associated with reduced life expectancy, advanced care planning and palliative care are also addressed.

Key Recommendations include:

• Echocardiogram (ECHO) is the gold standard for assessing structural and/or functional cardiac abnormalities and determining ejection fraction to guide treatment planning.
• BNP and NT-proBNP tests have a high sensitivity for the detection of heart failure (HF) and can help with diagnosis while waiting for echocardiogram.
• There are cornerstone therapies that improve clinical outcomes (e.g., reduced hospitalizations, and mortality, improved quality of life) in patients with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) necessitating their rapid implementation in eligible patients.
• NEW: It is recommended that in the absence of contraindications, patients with HFrEF be treated with combination therapy including one medication from each of the following categories: Angiotensin receptor-neprilysin inhibitors (ARNI) [or Angiotensin-converting enzyme inhibitors (ACEI)/Angiotensin receptor blockers (ARB)]; beta-blockers (β-blockers); Mineralocorticoid receptor antagonists (MRA); and Sodium-glucose cotransporter-2 inhibitors (SGLT2i). These four medications should be initiated and titrated in parallel as quickly as possible.
• Patient and caregiver education about the importance of self-monitoring and early identification of disease decompensation is crucial to avoid hospitalization and to inform acute treatment.
• Consider referral to a heart function clinic or a multi-disciplinary chronic disease management clinic, where available.
• Initiate advance care planning discussions early in the disease course.
• Incorporate a palliative approach as the disease progresses and/or as per patient preference. 

The Warfarin guideline provides recommendations for the primary care management of warfarin therapy in adults aged ≥ 19 years. This guideline describes: 1) initiation, 2) international normalized ratio (INR) monitoring with optimal ranges, and 3) dosage adjustment. Indications and decision to treat with warfarin, elective interruption, and emergency reversal are all outside the scope of this guideline.

Key recommendations include:

• Having a warfarin management plan that includes dosing tools, ongoing patient education and follow-up involving caregivers and other health professionals (e.g., pharmacists, dieticians, nurses) can maximize benefits and safety, and increase adherence.
• Warfarin should be dosed to achieve the target INR for a specific indication. This is preferred over accepting values at the outer bounds of the therapeutic range (i.e., target INR ±0.5).
• Consider using a standard dosing nomogram or computerized decision-support software to maximize the probability of achieving the target INR.
• Routine INR monitoring is necessary to measure the achieved anticoagulant effect and determine if dose changes are necessary.
• Because the anticoagulant effect (onset and offset) of warfarin is delayed, dose changes more than twice a week are not recommended during chronic therapy.
• Dose changes are not necessary for transient fluctuations in the INR due to short-term medication use (e.g., antibiotics).
• INR testing may be warranted within a week of initiating a new medication that has relevant drug-drug interactions with warfarin.
• Warfarin cannot achieve a therapeutic effect within the first five days, regardless of INR. As such, when warfarin is used to treat acute thrombosis, low molecular weight heparin (LMWH) or unfractionated heparin must be used concomitantly for at least five days.
• There are no dietary restrictions for patients taking warfarin. Patients should maintain a regular and consistent diet. This is especially true for vitamin K intake. 

The Direct Acting Oral Anticoagulants (DOACs) guideline provides recommendations on the use of direct acting oral anticoagulants (DOACs) in adults aged ≥19 years for the following indications:

• prevention of stroke and systemic embolism in non-valvular atrial fibrillation (NVAF);
• treatment of hemodynamically stable venous thromboembolism (VTE); and,
• prevention of arterial vascular events in patients with stable coronary artery disease with or without peripheral artery disease.

How to make the decision to use a DOAC (instead of another anticoagulant), periprocedural management, and emergency reversal are all outside the scope of this guideline.

Key recommendations include:

• DOACs are considered first-line therapy for:
  • prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF) for whom anticoagulation is indicated; and
  • treatment of hemodynamically stable venous thromboembolism (VTE).
  • Do not use DOACs (instead of warfarin) for anticoagulation in mechanical heart valves, AF with moderate to severe mitral stenosis, and other very high-risk thrombotic indications.
  • Confirm appropriate dosing as this varies widely across different indications. Dose adjustments may be indicated for renal impairment, age, weight, and drug-drug interactions.
  • Check renal function for all patients and liver function in patients with known hepatic dysfunction prior to initiating a DOAC. Monitor one or both periodically, based on clinical status.
  • DOACs do not require routine laboratory monitoring. International normalized ratio (INR) and activated partial thromboplastin clotting time (aPTT) values do not reflect anticoagulant level or activity and should not be used to detect or exclude the presence of a DOAC.
  • Check for potential drug-drug interactions and consider alternative therapy if a significant interaction is present. 

This guideline provides recommendations for the management of direct oral anticoagulants (DOACs) and warfarin in patients aged ≥ 19 years who require an elective or urgent procedure or are actively bleeding and require emergency reversal.

Key recommendations include:

• Whenever possible, procedures in an anticoagulated patient should be undertaken on an elective basis to allow for planned periprocedural anticoagulation.
• Whenever possible, discuss appropriate periprocedural anticoagulant management with the practitioner performing the procedure.
• Temporary interruption of an oral anticoagulant is not indicated for procedures with minimal risk of bleeding. All other procedures require temporary drug interruption. The duration of interruption is based on the type of anticoagulant, the risk of thrombosis, and the risk of bleeding related to the procedure.
• Bridging with low molecular weight heparin (LMWH) is only indicated for patients on warfarin with very specific and high-risk factors for thrombosis. Bridging is not indicated for DOACs.
• Rapid reversal of anticoagulants is indicated for patients with potentially life-threatening bleeding or patients who require an urgent/emergent procedure.
• Rapid reversal of warfarin is achieved with prothrombin complex concentrate (PCC) co-administered with vitamin K.
• Rapid reversal of dabigatran is achieved with idarucizumab.
• A specific agent for reversal of direct factor Xa (FXa) inhibitors (apixaban, edoxaban, and rivaroxaban) is not available in Canada. PCC has been used off-label for rapid reversal of these agents in life-threatening bleeding based on very weak evidence.
• In patients on chronic therapeutic dosing of a DOAC who undergo major surgeries that use prophylactic dosing of the DOAC post-operatively, timing of when to restart the therapeutic dose should be discussed with the surgeon.