July 3rd, 2012

Many CHF Patients Not Receiving – Or Getting Benefits From – High Dose ACE Inhibitors and ARBs

Although current guidelines recommend that ACE inhibitors and angiotensin-receptor blockers (ARBs) be used in high doses in patients with congestive heart failure, many CHF patients currently receive lower than recommended doses of these drugs. In a research letter published online in Archives of Internal Medicine, investigators in Montreal analyzed data from 43,405 patients with a first hospital admission for CHF in Quebec, 73% of whom received an ACE inhibitor and 27% an ARB.

Patients were classified as receiving low-, medium-, or high-dose drugs. Twenty-nine percent received a low dose. The groups were not evenly matched: patients in the high-dose group were more likely to have hypertension and diabetes, while patients in the low-dose group were more likely to have renal disease.

After adjusting for other factors, the risk of dying or being readmitted to the hospital was significantly reduced in the high-dose group. Here are the hazard ratios for ACE inhibitors and ARBs (medium dose serves as the reference):

ACE Inhibitor Mortality:

  • Low dose: 1.16 (1.12-1.20)
  • High dose: 0.90 (0.86-0.94)

ACE Inhibitor Mortality or CHF Readmission:

  • Low dose: 1.09 (1.05-1.13)
  • High dose: 0.93 (0.89-0.96)
ARB Mortality:
  • Low dose: 1.15 (1.06-1.24)
  • High dose: 0.93 (0.87-1.00)

ARB Mortality or CHF Readmission:

  • Low dose: 1.18 (1.09-1.27)
  • High dose: 0.95 (0.89-1.02)

The authors concluded that “physicians should strive, whenever possible, to treat patients with CHF with high doses of ACE inhibitors or ARBs to improve outcomes.”

4 Responses to “Many CHF Patients Not Receiving – Or Getting Benefits From – High Dose ACE Inhibitors and ARBs”

  1. Hypotension is often dose limiting. People with low BP tend to do worse than those with higher BP.Did the study control for baseline BP?

  2. Edgar Abovich, MD says:

    I suspect that patients discharged on lower doses were sicker to begin with and couldn’t tolerate higher doses. So therefore the best way to improve outcomes is “when possible” to pick healthier patients.

  3. Charles Weart, Pharm D says:

    I would tend to agree that most patients are not being treated with either ACEI/ARB, evidence-based beta blockers or even evidence-based statins to the target doses used in the evidence-based trials. Based upon the trial data most patients were able to reach target doses of these evidence-based agents and if we hope to replicate the benfits demonstrated then we should also try to replicate the doses that produced the results. While not everyone can tolerate these doses most patients can and they probably do better than we allow. Therapeutic inertia is still, alive and well in healthcare!

  4. Interesting- but it is not known whether receiving lower doses is a “marker of risk” or the cause of worse outcomes, or both. At least some patients may have received the lower doses because of problems with tolerating higher doses (e.g. BP, electrolyte imbalances, renal impairment).