Angioplasty: diabetics were not clearly at increased risk of restenosis.

Clinical bottom line (level 2b)

  1. Coronary restenosis was greater in diabetic patients than in nondiabetic patients after atherectomy (NNF = 8 for 12 months) , but not clearly so after angioplasty.
  2. Around 10% of patients who had angioplasty had an acute complication- half had an MI, and a quarter required emergency bypass.
Levine et al: American Journal of Cardiology 1997; 79: 748-755
Expires June 2003

The study

Inception cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: 32 centres in the US and 3 in Europe

1012 patients (aged mean 59 years, 73% male) symptomatic myocardial ischaemia with >60% stenosis of a native coronary artery

Excluded if
  • previous intervention for the target lesion


    • patients were taken from a randomised trial of percutaneous transluminal coronary angioplasty (n=500) versus directional atherectomy (n=512)

    100% followed for 12 months
    Outcomes studied:
  • restenosis after atherectomy
  • restenosis after angioplasty

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    restenosis after atherectomy 12 months 255/512 49.8%
    (45.5% to 54.1%)
    restenosis after angioplasty 12 months 276/500 55.2%
    (50.8% to 59.6%)

    prognostic factor for
    restenosis after atherectomy     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    diabetes 12 months 1.26
    (1.04 to 1.53)     		8
    (4 to 50)

    prognostic factor for
    restenosis after angioplasty     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    diabetes 12 months 1.02
    (0.84 to 1.25)     		77
    (-11 to 7)

    • Initial success rates did not differ between diabetic and nondiabetic patients for atherectomy (87.8% vs 89.2%) or angioplasty (75% vs 80.7%).
    • Acute procedure complication rates also did not differ (5.2% vs 8.9%, p=0.097), (death 0.24%, any MI 5.2%, emergency CABG 2.8%, or abrupt closure 6.2%).

    Comments

    1. No adjustment for confounding factors- diabetic patients were more often women, and had higher rates of hypertension, peripheral vascular disease, heart failure and other co-morbid disease.
    2. Further studies have examined this issue and found a relationship between glycaemic control and rates of restenosis

    Citation

    1. Levine GN, Jacobs AK, Keeler GP, et al: Impact of diabetes mellitus on percutaneous revascularization (CAVEAT-I). American Journal of Cardiology 1997; 79: 748-755
    Search Terms: angioplasty in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Andreas Michaelides

    Clinical Question.
    Patient myocardial ischaemia
    Intervention or Exposure diabetes
    Outcome restenosis