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)