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Evidence summaries

Coronary Artery Bypass Grafting (Cabg) Versus Medical Treatment

Revascularization by CABG appears to be more effective than medical treatment alone in reducing symptoms and it may be more effective in preventing total mortality and myocardial infarction in patients with coronary heart disease. Level of evidence: "B"

A topic in Clinical Evidence 1 summarizes the evidence on the effectiveness of CABG versus medical treatment. 8 RCTs were included with a total of 3260 patients. RCTs performed up to the mid 1980s found a greater risk of death in the first year but a reduced risk at 5 - 10 years. A subsequent RCT 3 found that revascularisation decreased mortality at 2 years (absolute risk of death 1.1% with routine revascularisation vs 6.6% and 4.4% in the two medical treatment groups. Revascularization mortality or rates of myocardial infarction at 1 and 2 years vs medical treatment (AR of myocardial infarction or death 4.7% with revascularisation versus 8.8% with symptom guided treatment vs 12% with symptom plus electrocardiogram guided treatment. A recent RCT 2 found that at one year CABG reduced symtoms of angina but showed no difference in mortality or infarction (survival 96.0% with CABG v 98.5% with medical treatment alone; myocardial infarction free survival: 98% with CABG v 97% with medical treatment alone).

Comment: The quality of evidence is downgraded by indirectness (both medical treatment and surgical techniques have developed after the trials were performed).

    References

    • Rihal C. What are the effects of surgical treatments. In: Secondary prevention of ischaemic cardiac event. Clinical Evidence 2007. Web publication date: 01 Dec 2005 (based on July 2004 search) .
    • Hueb W, Soares PR, Gersh BJ, César LA, Luz PL, Puig LB, Martinez EM, Oliveira SA, Ramires JA. The medicine, angioplasty, or surgery study (MASS-II): a randomized, controlled clinical trial of three therapeutic strategies for multivessel coronary artery disease: one-year results. J Am Coll Cardiol 2004 May 19;43(10):1743-51. [PubMed]
    • Davies RF, Goldberg AD, Forman S, Pepine CJ, Knatterud GL, Geller N, Sopko G, Pratt C, Deanfield J, Conti CR. Asymptomatic Cardiac Ischemia Pilot (ACIP) study two-year follow-up: outcomes of patients randomized to initial strategies of medical therapy versus revascularization. Circulation 1997 Apr 15;95(8):2037-43. [PubMed]

Primary/Secondary Keywords