Tag Archives: guideline

A Fib 2: CCS 2012 Treatment Guidelines

The CHADS2 and HAS-BLED predictive index are useful in assessing a patient’s thromboembolic risk and in predicting which antithrombotic therapy is most suitable; and that is either aspirin, clopidogrel, or anticoagulants. The 3 new anticoagulants may be simpler to use and may have less intracranial hemorrhage side effect than warfarin, there has been longer clinical experience with warfarin and an antidote is present if needed.

As for rate control and rhythm control, there is no significant difference in controlling survival and mortality between the two. Therapy is chosen based on patient’s symptoms and preference. Rate control medications include BB, non-dihydropyridine CCB, and digoxin. And rhythm control includes dronedarone, flecainide, sotalol, and amiodarone. We will go over details of these medications in the next episode.

Catheter ablation is mainly for symptom control. It may be first line for highly selected patients,  is often considered 2nd line after multiple drug therapy, or for patients who failed on multiple antiarrhythmic therapy and maintenance of sinus rhythm is still desired.

  • Focused 2012 Update of the Canadian Cardiovascular Society Atrial Fibrillation Guidelines: Recommendations for Stroke Prevention and Rate/Rhythm Control

http://www.onlinecjc.ca/article/S0828-282X(12)00046-3/fulltext

  • The 2012 Canadian Cardiovascular Society Heart Failure Management Guidelines Update: Focus on Acute and Chronic Heart Failure

http://www.onlinecjc.ca/article/S0828-282X%2812%2901379-7/abstract

  • Canadian Cardiovascular Society Atrial Fibrillation Guidelines 2010: Catheter Ablation for Atrial Fibrillation/Atrial Flutter

http://www.onlinecjc.ca/article/S0828-282X(10)00012-7/fulltext

CHF 1: CCS 2012 Guideline

We turned our attention to chronic congestive heart failure (CHF) and reviewed “The 2012 Canadian Cardiovascular Society Heart Failure Management Guidelines Update“.

National Institute of Health provided a great summary on CHF for patients and the public: http://www.nhlbi.nih.gov/health/health-topics/topics/hf/

For a basic anatomy review of the circulatory system:

Anatomy of the heart. Source: Wikimedia. 

For another diagram showing the heart in relation to the body, click here.

And an over-simplification of the pathophysiology of left vs right heart failure is that when the left ventricle fails, not enough oxygenated blood gets pumps to the body to meet its demand. Instead, blood gets backed up into the lungs and cause fluid buildup in the lungs. This pressure can further back up into the right heart, such that the right ventricle and right atrium cannot accommodate a normal amount of venous return, and fluid can accumulate in the body to cause edema. Wikipedia strikes a good balance of depth and readability on this topic: http://en.wikipedia.org/wiki/Heart_failure

The CCS guideline suggests the following investigations for CHF:

  • CXR,
  • echocardiography,
  • BNP,
  • labs (CBC, electrolytes, creatinine, urinalysis, glucose, thyroid function), and
  • further testing (nuclear imaging, catheterization, stress test, MRI, CT, endomyocardial biopsy) if appropriate.

The CCS guideline on treatment of chronic CHF:

ACE inhibitors for:

  • all symptomatic HF patients and EF < 40%.
  • all patients with an EF < 35%

Angiotensin receptor blocker:

  • if patient intolerant to ACEI
  • add to ACEI if intolerant or contraindicated for BB
  • add to ACEI and BB if patient has NYHA class II-IV HF and EF ≤ 40% deemed at increased risk of HF events

Beta blocker:

  • all HF patients with an EF ≤ 40%
  • initiated at a low dose and titrated to the target dose or maximal tolerated dose

Mineralocorticoid receptor antagonist:

  • EF <30% and one of the following:
    • past MI and HF
    • diabetes
    • severe chronic HF (NYHA IIIB-IV) despite optimized treatment
    • age >55 with HF symptoms on treatment and recent hospitalization for CV disease in the past 6 months (or if QRS duration > 130ms and EF <35%)
  • with elevated BNP or NT-proBNP levels

Diuretics:

  • loop diuretic, such as furosemide, for most patients with HF and congestive symptoms. When acute congestion is cleared, the lowest dose should be used that is compatible with stable signs and symptoms
  • persistent volume overload despite optimal medical therapy and increases in loop diuretics, cautious addition of a second diuretic (a thiazide or low dose metolazone) may be considered as long as it is possible to closely monitor morning weight, renal function, and serum potassium

Digoxin:

  • patients in sinus rhythm who continue to have moderate to severe symptoms, despite optimized HF therapy
  • patients with chronic atrial fibrillation (AF) and poor control of ventricular rate

Isosorbide dinitrate and hydralazine:

  • black Canadians with HF-REF
  • non-black HF patients unable to tolerate an ACE inhbitor or ARB

Hypertension 4: EBM Special

We reviewed some evidence on the treatment of hypertension that are contradictory to the CHEP 2013 guidelines summarized in our previous episodes.

Salt restriction for hypertension

CHEP 2013: 1500 mg of sodium per day is recommended for adults age 50 years or less; 1300 mg per day if age 51 to 70 years; and 1200 mg per day if age greater than 70 years

Tools for practice: “Cutting out the sodium: The bland supremacy?” http://www.acfp.ca/Portals/0/docs/TFP/20130204_084845.pdf

“The impact of salt intake on CVD outcomes is controversial. Trials demonstrating beneficial trends enrolled patients with an average sodium intake of 3900 mg/day and reduced their intake on average by 900mg/day. More evidence with clinical outcomes is required to better define benefits/harms with different levels of daily sodium intake.”

Hypertension treatment target for diabetes

CHEP 2013: BP target for diabetes is 130/80mmHg, and 140/90 for others

Cochrane: “Blood pressure targets for hypertension in people with diabetes mellitus” http://summaries.cochrane.org/CD008277/blood-pressure-targets-in-people-with-diabetes

“The only significant benefit in the group assigned to ‘lower’ systolic blood pressure was a small reduction in the incidence of stroke (ACCORD 1.1%ARR SBP <140 vs <120), but with a significantly larger increase in the number of other serious adverse events (ARI 2%). The effect of systolic blood pressure targets on mortality was compatible with both a reduction and increase in risk. There was no benefit associated with a ‘lower’ diastolic blood pressure target (trend towards less stroke RR 0.67, 95% CI 0.42 to 1.05)”

Tools for Practice: “When Treating Blood Pressure, what is the Evidence for Specific Targets?” http://www.acfp.ca/Portals/0/docs/TFP/20111028_103346.pdf

Treating mild hypertension

CHEP 2013: treatment threshold 160/100, treatment target 140/90 for uncomplicated hypertension

Cochrane: “Pharmacotherapy for mild hypertension” http://summaries.cochrane.org/CD006742/benefits-of-antihypertensive-drugs-for-mild-hypertension-are-unclear

“For individuals with mildly elevated blood pressures(systolic blood pressure (BP) 140-159 mmHg and/or diastolic BP 90-99 mmHg) treatment for 4 to 5 years with antihypertensive drugs as compared to placebo did not reduce total mortality (RR 0.85, 95% CI 0.63, 1.15). In 7,080 participants treatment with antihypertensive drugs as compared to placebo did not reduce coronary heart disease (RR 1.12, 95% CI 0.80, 1.57), stroke (RR 0.51, 95% CI 0.24, 1.08), or total cardiovascular events (RR 0.97, 95% CI 0.72, 1.32). Withdrawals due to adverse effects were increased by drug therapy (RR 4.80, 95%CI 4.14, 5.57), Absolute risk increase (ARI) 9%.”

Which first line agent for hypertension is actually first line?

CHEP 2013:  beta-blocker is considered a first line choice in patients younger than 60 years of age (Grade B), among ACEI, ARB, thiazides, CCB

Therapeutics Initiative Letter #82: “Clinical Hypertension Pearls from The Cochrane Library” http://www.ti.ubc.ca/letter82

Cochrane: “First-line drugs for hypertension” http://summaries.cochrane.org/CD001841/thiazides-best-first-choice-for-hypertension

mortality stroke CHD CVS
Thiazides (19 RCTs) RR 0.89, 95% CI 0.83, 0.96 RR 0.63, 95% CI 0.57, 0.7 RR 0.84, 95% CI 0.75, 0.95 RR 0.70, 95% CI 0.66, 0.76
Low-dose thiazides (8 RCTs) RR 0.72, 95% CI 0.61, 0.84
high-dose thiazides (11 RCTs) RR 1.01, 95% CI 0.85, 1.20
Beta-blockers (5 RCTs) RR 0.96, 95% CI 0.86, 1.07 RR 0.83, 95% CI 0.72, 0.97 RR 0.90, 95% CI 0.78, 1.03 RR 0.89, 95% CI 0.81, 0.98
ACE inhibitors (3 RCTs) RR 0.83, 95% CI 0.72-0.95 RR 0.65, 95% CI 0.52-0.82 RR 0.81, 95% CI 0.70-0.94 RR 0.76, 95% CI 0.67-0.85
Calcium-channel blocker (1 RCT) RR 0.86 95% CI 0.68, 1.09 RR 0.58, 95% CI 0.41, 0.84 RR 0.77 95% CI 0.55, 1.09 RR 0.71, 95% CI 0.57, 0.87
ARB (no RCT)

“Most of the evidence demonstrated that first-line low-dose thiazides reduce mortality and morbidity (stroke, heart attack and heart failure). No other drug class improved health outcomes better than low-dose thiazides, and beta-blockers and high-dose thiazides were inferior. Low-dose thiazides should be the first choice drug in most patients with elevated blood pressure. Fortunately, thiazides are also very inexpensive.”

Tools for Practice: “Is hydrochlorothiazide the best thiazide diuretic for hypertension?” http://www.acfp.ca/Portals/0/docs/TFP/20120206_092015.pdf

Cochrane: “Calcium channel blockers versus other classes of drugs for hypertension” http://www.ncbi.nlm.nih.gov/pubmed/20687074 

Cochrane: “Beta-blockers for hypertension” http://summaries.cochrane.org/CD002003/beta-blockers-for-hypertension

“Angiotensin receptor blockers versus ACE inhibitors: prevention of death and myocardial infarction in high-risk populations”. http://www.ncbi.nlm.nih.gov/pubmed/15701766

“Angiotensin-converting enzyme inhibitors (ACEIs), not angiotensin receptor blockers (ARBs), are preferred and effective mode of therapy in high cardiovascular risk patients.” http://www.ncbi.nlm.nih.gov/pubmed/19810392

What time should a patient take the blood pressure medications?

Tools for practice: “Taking blood pressure-lowering medications at night” http://www.acfp.ca/Portals/0/docs/TFP/20120109_102035.pdf

“Taking one or more BP meds before bed may potentially help reduce cardiovascular risk but due to limitations of the evidence, strong recommendations are difficult.”

MAPEC trialhttp://www.ncbi.nlm.nih.gov/pubmed/20854139

Side note about confidence interval worship

I mentioned how a statistically insignificant risk reduction in stroke could actually be clinically significant. Check out this article by Dr McCormack et al on “How confidence intervals become confusion intervals” on this very topic. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3818447/

(Originally published on January 18, 2014.)