Coronary artery bypass grafting (CABG) surgery is a major operation that uses arteries or veins from the body to reroute blood around a blockage in the coronary arteries (the arteries that supply blood and oxygen to the heart).
Fewer women than men undergo CABG, and CABG research — along with other heart research — has focused on male patients for many years. However, there have now been a number of studies on how women fare after bypass surgery.
Studies show an increased hospital death rate after CABG in women compared with men.1-3 This difference is more pronounced in younger women (particularly in women under 50 and in the 50-59 age group)4 and has been attributed to such factors as how doctors refer women and men for treatment, smaller vessels in women, and decreased body size and more additional medical conditions in women.5-8 At the same time, studies show that women still derive the same long-term benefits from CABG as men.8,9
Improving CABG outcome in women
Although debate continues on why women have a higher early death rate after CABG than men, several surgical techniques may improve outcomes for women having the procedure.
A variation of CABG surgery called off-pump coronary artery bypass (OPCAB) has been shown to reduce death rates in women and to yield rates equivalent to those of men.10,11 OPCAB makes heart surgery less invasive because the patient is not placed on cardiopulmonary bypass. OPCAB is performed on a beating heart with the use of stabilizers that stabilize the artery being bypassed.
This procedure differs from conventional bypass surgery, in which patients are placed on cardiopulmonary bypass, which includes rerouting the blood outside the body and stopping the heart during surgery. By avoiding cardiopulmonary bypass, the risk of stroke and pulmonary complications may be reduced. Other important advantages of OPCAB may include reduced need for blood transfusions, less heart muscle injury, shorter hospital stay, and reduced stroke risk.
As in conventional bypass surgery, the surgeon uses a sternotomy (mid-chest incision) to access the heart. Although patients are discharged sooner with OPCAB, the four-to-six week healing time from the sternotomy is similar to the conventional procedure.
Along with OPCAB, the selection of certain types of grafts for a CABG procedure may benefit female patients. Using the left internal mammary artery for the bypass graft has been shown to prolong survival, but it has been used infrequently in women in the past.12,13 In addition, a smaller percentage of women than men have been demonstrated to receive a radial arterial graft for bypass. In a study conducted at Washington University School of Medicine and Barnes-Jewish Hospital, the five–year survival rate was significantly better for 294 women who received the radial artery graft than for those who did not have a radial artery as a bypass graft.14 The use of the left internal mammary artery and radial artery for bypass grafts in women is vital because these grafts tend to remain open or unobstructed over a longer period of time compared to vein grafts from the leg.12,14
Long-term results of CABG in women
Studies have shown that although women have higher early mortality, they have long-term results similar to men. A study of 54,425 patients (12,079 women) who underwent CABG in the Canadian province of Ontario found that the long-term death risk for women appeared equal to or even better than that of men as early as one year after CABG.15 Another study of 2,000 patients (381 women) in Western Sweden reported that women had a higher risk of in-hospital death and death associated with stroke; however, the adjusted risk of death during 5 years was equal in women and men.16 Finally, a multi-center study in the United States and Canada that followed more than 1,800 patients who underwent CABG or percutaneous transluminal coronary angioplasty (PTCA) found that women and men had a similar 5-year mortality.17
Washington University heart surgeons who perform OPCAB or specialize in treating women with heart disease
Washington University heart surgeon Ralph Damiano Jr., MD, performs the OPCAB procedure in women and men.
For a consultation regarding a heart condition, call:
- Tyras DH, Barner HB, Kaiser GC, Codd JE, Laks H, Willman VL. Myocardial revascularization in women. Ann Thorac Surg. 1978;25:449–453.
- Loop FD, Golding LR, MacMillan JP, Cosgrove DM, Lytle BW, Sheldon WC. Coronary artery surgery in women compared with men: analysis of risk and long term results. J Am Coll Cardiol 1983;1:383–390.
- Gardner TJ, Horneffer PJ, Gott VL, Watkins Jr L, Baumgartner WA, Borkon AM et al. Coronary artery bypass grafting in women. Ann Surg. 1985; 201:780–784.
- Vaccarino V, Abramson JL, Veledar E, Weintraub WS. Sex differences in hospital mortality after coronary artery bypass surgery: evidence for a higher mortality in younger women. Circulation. 2002;105(10):1176-1181.
- Khan SS, Nessim S, Gray R, Czer LS, Chaux A, Matloff I. Increased mortality of women in coronary artery bypass surgery: evidence for referral bias. Ann Intern Med. 1990;112:561–567.
- Edwards FH, Carey JS, Grover FL, Bero JW, Hartz RS, Impact of gender on coronary bypass operative mortality. Ann Thorac Surg. 1998; 66:125–131.
- O’Connor GT, Morton JR, Diehl MJ, Olmstead EM, Loffin LH, Levy DG et al. Differences between men and women in hospital mortality associated with coronary artery bypass graft surgery. Circulation. 1993;88:2104–2110.
- Mickleborough, LL, Takagi Y, Mariyama H, Sun Z, Mohamed S. Is sex a factor in determining operative risk for aortocoronary bypass surgery? Circulation. 1995;92(suppl I):1180- 1184.
- Herlitz J, Brandrup-Wognsen G, Karlson BW, Sjoland H, Karlsson T, Caidahl K et al. Mortality, risk indicators of death, mode of death and symptoms of angina pectoris during 5 years after coronary artery bypass grafting in men and women. J Intern Med. 2000;247:500–506.
- Petro KR, Dullum MK, Garcia JM, Pfister AJ, Qazi AG, Boyce SW, Bafi AS, Stamou SC, Corso PJ. Minimally invasive coronary revascularization in women: A safe approach for a high-risk group. Heart Surg Forum. 2000;3(1):41-46.
- Brown PP, Mack MJ, Simon AW, Battaglia S, Tarkington L, Horner S, Culler SD, Becker ER. Outcomes experience with off-pump coronary artery bypass surgery in women. Annals of Thoracic Surgery. 2002;74(6):2113-2119; discussion 2120.
- Loop FD, Lytle BW, Cosgrove DM, Stewart RW, Goormastic M, Williams GW, Golding LA, Gill CC, Taylor PC, Sheldon WC, et al. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. New England Journal of Medicine. 1986;314(1):1-6.
- Jacobs AK, Kelsey SF, Brooks MM, Faxon DP, Chaitman BR, Bittner V, Mock MB, Weiner BH, Dean L, Winston C, Drew L, Sopko G. Better outcome for women compared with men undergoing coronary revascularization: a report from the bypass angioplasty revascularization investigation (BARI). Circulation. 1998;98(13):1279-1285.
- Lawton JS, Barner HB, Bailey MS, Guthrie TJ, Moazami N, Pasque MK, Moon MR, Damiano RJ Jr. Radial artery grafts in women: utilization and results. Annals of Thoracic Surgery. 2005;80(2):559-563.
- Guru V, Fremes SE, Tu JV. Time-related mortality for women after coronary artery bypass graft surgery: a population-based study. J Thorac Cardiovasc Surg. 2004 Apr;127(4):1158-1165.
- J. Herlitz, G. Brandrup-Wognsen, B. W. Karlson, H. Sjöland, T. Karlsson, K. Caidahl, M. Hartford & M. Haglid. Mortality, risk indicators of death, mode of death and symptoms of angina pectoris during 5 years after coronary artery bypass grafting in men and women. Journal of Internal Medicine. 2000;247(4):500-506.
- Jacobs AK, Kelsey SF, Brooks MM, Faxon DP, Bernard R. Chaitman BR, Bittner V, Mock MB, Weiner BH, Dean L, Winston C, Drew L, Sopko G. Better outcome for women compared with men undergoing coronary revascularization: A report from the Bypass Angioplasty Revascularization Investigation (BARI). Circulation. 1998;98:1279-1285.