Unstable angina: early revascularisation reduced hospital admissions, myocardial infarction and death

Clinical bottom line (level 1b)

  1. Patients with acute coronary syndrome who received early revascularisation compared with medical therapy and revascularisation as required were less likely to have a myocardial infarction (NNT = 33 at 12 months) , be admitted to hospital (NNT = 5 at 12 months) , or die (NNT = 60 at 12 months) .
  2. Patients receiving early revascularisation were less likely to require a subsequent PTCA (NNT = 9 at 12 months) or CABG (NNT = 8 at 12 months) .
FRISC II investigators : Lancet 1999; 354 : 708-715
Wallentin et al: Lancet 2000; 356 : 9-16
Expires January 2004

The study

Unblinded ?concealed randomised trial with intention-to-treat
Setting: 58 acute hospital, Scandinavia

2457 patients (aged median 66, 70% male) with symptoms of ischaemia that were increasing or occurring at rest or a suspected myocardial infarction (confirmed on ECG or cardiac enzymes)

Excluded if
  • other acute or severe cardiac disease
  • renal or hepatic insufficiency, or other severe illness
  • known clinically relevant osteoporosis
  • hypersensitivity to study drugs
  • participation in another clinical trial
  • aged > 75
  • increased risk of bleeding episodes
  • anaemia
  • indication for or treatment in the past 24 hours with thrombolysis
  • angioplasty in last 6 months
  • on waiting list for coronary revascularisation, or previous open heart surgery
  • most recent episode of chest pain > 48 hours ago

Control Group: (n = 1235, 1234 analysed): non-invasive strategy: coronary angiography if refractory or recurrent symptoms despite maximum medical therapy, or severe ischaemia on limited exercise testing before discharge; followed by revascularisation if required
Experimental Group: (n = 1222, 1222 analysed): invasive strategy: revascularisation within 7 days. Recommended in all patients if any artery supplying a substantial part of the myocardium > 70% stenosed. Patients with 1 or 2 vessel disease received PTCA; patients with 3 vessel disease or left main stem disease CABG.
Patients received dalteparin until a procedure or for at least 5 days. After this patients were randomised to dalteparin or placebo for 3 months. All patients received aspirin, beta-blockers, and nitrates, statins, ACE inhibitors and calium antagonists if required. Abciximab and stent insertion was recommended during angioplasty.
99.9% followed for 12 months

The evidence

Outcome Time to outcome CER EER RRR
(95% CI)		 ARR
(95% CI)		 NNT
(95% CI)
myocardial infarction 12 months 143
(11.6%)		 105
(8.59%)		 26%
(6% to 42%)		 2.99%
(0.61% to 5.36%)		 33
(19 to 160)
death 12 months 48
(3.89%)		 27
(2.21%)		 43%
(10% to 64%)		 1.68%
(0.320% to 3.03%)		 60
(33 to 310)
readmission to hospital 12 months 704
(57.0%)		 451
(36.9%)		 35%
(29% to 41%)		 20.1%
(16.2% to 24.0%)		 5
(4 to 6)
angioplasty 12 months 192
(15.6%)		 60
(4.91%)		 68%
(58% to 76%)		 10.6%
(8.28% to 13.0%)		 9
(8 to 12)
CABG 12 months 199
(16.1%)		 39
(3.19%)		 80%
(72% to 86%)		 12.9%
(10.7% to 15.2%)		 8
(7 to 9)

  • 71% of invasive strategy patients were revascularised within 10 days, rising to 77% within 6 months.
  • 9% of non-invasive strategy patients were revascularised within 10 days, rising to 37% at 6 months.

Comments

  1. Revascularisation was considered for any patient with incapacitating symptoms, recurrence of instability or myocardial infarction.

Citation

  1. FRISC II investigators , : invasive compared with non-invasive treatment in unstable coronary-artery disease: FRISC II prospective randomised multicentre study. Lancet 1999; 354 : 708-715
  2. Wallentin L, Lagerqvist B, Husted S, et al: outcome at 1 year after an invasive compared with non-invasive strategy in unstable coronary-artery disease: FRISC II invasive randomised trial. Lancet 2000; 356 : 9-16
Search Terms: from ACP Journal Club
Contributor: Chris Ball, January 2002
Reviewer:

Clinical Question.
Patient acute coronary syndrome
Intervention or Exposure early revascularisation
Comparison medical therapy and revascularisation if required
Outcome death, myocardial infarction, further revascularisation, admission to hospital