Coronary artery disease: no clear effect on treating C. pneumoniae seropositive patients with antibiotics

Clinical bottom line (level 1b-)

  1. Patients with known coronary artery disease, seropositive for Chlamydia pneumoniae, who received azithromycin compared with placebo were not clearly less likely to have a MI, unstable angina, coronary surgery or a cardiovascular death.
Muhlestein et al: Circulation 2000; 102 : 1755-1760
Expires February 2004

The study

Double-blinded ?concealed randomised trial with intention-to-treat
Setting:

302 patients (aged 64, 89% male) with documented coronary artery disease (previous MI, bypass surgery, or > 50% stenosis of 1 major vessel on arteriography) and seropositive to Chlamydia pneumoniae

Excluded if
  • significant co-morbidity: active malignancy, ongoing drug or alcohol abuse, renal failure requiring dialysis, liver failure
  • known intolerance to azithromycin, or chronic macrolide use
  • aged < 18
  • life expectancy < 2 years
  • childbearing potential and no adequate birth control
  • heart failure: NYHA class III or IV, or LV ejection fraction < 25%
  • recent MI (within 5 days), CABG (within 4 weeks), PTCA (within 3 months)

Control Group: (n = 152, 152 analysed): placebo
Experimental Group: (n = 150, 150 analysed): azithromycin 500 mg daily for 3 days, then 500 mg once a week for 3 months

100% followed for 2 years
Outcome notes:
  • cardiac event : cardiovascular death, non-fatal MI, stroke, resuscitated cardiac death, unstable angina, unplanned coronary intervention

The evidence

Outcome Time to outcome CER EER RRR
(95% CI)		 ARR
(95% CI)		 NNT
(95% CI)
cardiac event 2 years 25
(16.5%)		 22
(14.7%)		 11%
(-51% to 47%)		 1.78%
(-6.39% to 9.95%)		 56
(NNT = 10 to infinity;
NNH = 16 to infinity)

Comments

  1. The study is too small to show a difference between the two groups.

Citation

  1. Muhlestein JB, Anderson JL, Carlquist JF, et al: randomized secondary prevention trial of azithromycin in patients with coronary artery disease: primary clinical results of the ACADEMIC study. Circulation 2000; 102 : 1755-1760
Search Terms: from ACP Journal Club other articles noted
Contributor: Chris Ball, February 2002
Reviewer:

Clinical Question.
Patient known coronary artery disease, seropositive for Chlamydia pneumoniae
Intervention or Exposure azithromycin
Comparison placebo
Outcome cardiovascular death, MI, stroke, coronary intervention