Unstable angina:refractory: thoracic epidural anaesthesia reduced episodes of angina and ischaemia.

Clinical bottom line (level 1b)

  1. Patients with severe refractory unstable angina who had thoracic epidural anaesthesia had fewer episodes of ischaemia (NNT = 3 at 48 hours) and angina (NNT = 1 at 48 hours) .
  2. Ischaemic attacks were shorter (by a mean 16 minutes).
  3. Side effects were common (urinary retention and Horner's syndrome) (NNH = 2 at 48 hours) , but are reversible.
Olausson et al: Circulation 1997; 96 (7): 2178-2182
Expires June 2003

The study

Unblinded concealed randomised trial without intention-to-treat
Setting: coronary care unit, university hospital, Sweden

40 patients (aged mean 65 years, 81% male) severe refractory unstable angina
  • typical chest pain occurring at rest associated with reversible ST-segment depression 0.1 mV or more, 60 msecs after the J-point, no development of new Q waves and maximal rise of CK-MB less than twice the upper normal limit
  • treatment with aspirin and/or heparin infusion
  • treatment with beta-blockers
  • treatment with nitroglycerin iv for more than 24 hours at an optimal infusion rate according to ischaemic symptoms and side effects
  • recurrence of chest pain or more severe chest pain during at least one attempt to discontinue the nitroglycerin infusion

Control Group: (n = 20, 18 analysed): continued maximal medical therapy
Experimental Group: (n = 20, 18 analysed): thoracic epidural anaesthesia (at one of T2 to T5 intercostal spaces)- bolus of 20-30 mg of bupivicaine (5mg/ml) followed by a continuous infusion for 48 hours (7.5-16 mg/hour) to maintain loss of temperature sensation to T1-T5. Heparin was discontinued 5 hours before the procedure, and nitroglycerin within 5 hours of anaesthesia working. All other medication was continued.

90% followed for 48 hours
Outcome notes:
  • ischaemic episode : on 24 hour ambulatory monitoring (reversible ST-segment changes lasting one minute, with a shift of =0.1 mV, 60 ms after the J-point)
  • side effects : urinary retention, Horner's syndrome

The evidence

Outcome Time to outcome CEREERRRR
(95% CI)		ARR
(95% CI)		NNT
(95% CI)
ischaemic episode 48 hours 11
(61.1%)		 4
(22.2%)		 64%
(7% to 86%)		 38.9%
(9.29% to 68.5%)		 3
(1 to 11)
anginal attack 48 hours 15
(83.3%)		 1
(5.56%)		 93%
(55% to 99%)		 77.8%
(57.6% to 98.0%)		 1
(1 to 2)
side effects 48 hours 0
(0.00%)		 10
(55.6%)		 inf%
(% to %)		 -55.6%
(-78.5% to -32.6%)		 -2
(-3 to -1)

Outcome Control Group
(SD)		 Experimental Group
(SD)		 Mean Difference
(95% CI)
length of ischaemic attack (min) 19.7
(6.20) 		4.10
(2.50) 		15.6
(12.4 to 18.8)

  • All side effects of thoracic anaesthesia were reversible on decreasing the dose of bupivicaine.

    • Comments

    1. Small study - potentially serious side effects may be missed.
    2. Short length of follow-up- what is the effect on overall mortality and infarctions?

    Citation

    1. Olausson K, Magnusdottir H, Lurje L, et al: Anti-ischemic and anti-anginal effects of thoracic epidural anesthesia versus those of conventional medical therapy in the treatment of severe refractory unstable angina pectoris. Circulation 1997; 96 (7): 2178-2182
    Search Terms: unstable angin* in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Kenneth Ballew

    Clinical Question.
    Patient severe unstable angina
    Intervention or Exposure thoracic epidural anaesthesia
    Comparison continued maximal medical therapy
    Outcome ischaemic episode, anginal attack, side effects