Unstable angina: diltiazem reduced chest pain.

Clinical bottom line (level 1b-)

  1. Diltiazem reduced chest pain in patients with unstable angina.
  2. It was not clearly better or worse than propranolol at preventing MI or death.
Theroux et al: Journal of the American College of Cardiology 1985; 5 (3): 717-722
Held et al: British Journal of Medicine 1989; 299: 1187-1192
Expires July 2003

The study

Single-blinded concealed randomised trial without intention-to-treat
Setting: university hospital, Canada

100 patients (aged ?, ?% male) clinical diagnosis of unstable angina. Diagnosed if:
  • crescendo angina defined by the presence of chest pain with a recent increase in frequency, intensity and duration
  • acute coronary insufficiency- prolonged ischaemic chest pain poorly relieved by nitroglycerin and without ECG or serum enzyme evidence of MI
  • spontaneous angina occurring 3 to 30 days after acute MI


Excluded if
  • current treatment with beta-blocker
  • variant angina
  • previous cardiac surgery or scheduled CABG
  • >65 years old
  • contraindication to study medication
  • follow-up impossible


    • Note:
  • Patients were randomised in blocks of nine.


    • Control Group: (n = 50, 50 analysed): propranolol 40 mg po; if well tolerated, dose increased to 80 mg po twice daily
    Experimental Group: (n = , analysed): diltiazem 60 mg po; if well tolerate, dose increased to 120 mg po twice daily
    All patients had bed rest, a mild sedative and isosorbide dinitrate 120 mg daily (or as tolerated). Aspirin not given. If patients continued to have chest pain, iv nitroglycerin was added. If pain still continued, patients were considered for early angiography and CABG.
    100% followed for 1-15 months

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    death 5 months 2
    (4.00%)    		 2
    (4.00%)    		 0%
    (-582% to 85%)    		 0.00%
    (-7.68% to 7.68%)    		 inf
    (NNT = 13 to infinity;
    NNH = 13 to infinity)
    MI 5 months 4
    (8.00%)    		 5
    (10.0%)    		 -25%
    (-338% to 64%)    		 -2.00%
    (-13.2% to 9.21%)    		 -50
    (NNT = 11 to infinity;
    NNH = 8 to infinity)
    CABG 5 months 19
    (38.0%)    		 21
    (42.0%)    		 -11%
    (-79% to 32%)    		 -4.00%
    (-23.2% to 15.2%)    		 -25
    (NNT = 7 to infinity;
    NNH = 4 to infinity)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    episodes of pain/day (SD) with propranolol vs placebo
    (.)     		0.26
    (0.07)     		0.49
    (0.46 to 0.52)
    episodes of pain/day with diltiazem vs placebo
    ()     		0.29
    (0.09)     		0.46
    (0.43 to 0.50)

  • Before therapy, episodes of pain/day were 0.75 (0.10).
  • No significant difference between propranolol and diltiazem, with regards to painful episodes.

    • Comments

    1. Note - no aspirin was given in this study.
    2. Study was too small to demonstrate harm from diltiazem. A systematic review (2) has failed to show any reduction in death or MI for patients with unstable angina or MI on calcium channel blockers.

    Citation

    1. Theroux P, Taeymans Y, Morissette D, et al: A randomised study comparing propranolol and diltiazem in the treatment of unstable angina. Journal of the American College of Cardiology 1985; 5 (3): 717-722
    2. Held PH, et al: Calcium channel blockers in acute myocardial infarction and unstable angina: an overview. British Journal of Medicine 1989; 299: 1187-1192
    Search Terms: angin* and diltiazem in Cochrane
    Contributor: Chris Ball and Clare Wotton, July 2000
    Reviewer: William Rhoton

    Clinical Question.
    Patient unstable angina
    Intervention or Exposure diltiazem
    Comparison beta-blockers, propranolol
    Outcome death, reinfarction, pain