Restoring flow to all blocked areas of the heart improves 5-year survival rate
Cardiothoracic surgeons at Cedars-Sinai Medical Center have found that patients who have blockages of multiple coronary arteries and undergo "complete revascularization" – grafting of arteries to restore blood flow to all affected territories of the heart – have consistently better long-term survival rates than those who have "incomplete revascularization."
The findings are based on a review of 1,034 patient cases with five-year follow-up, and are reported in The Journal of Thoracic and Cardiovascular Surgery.
" Our study centered on the various factors that make for the most successful coronary artery bypass operation, and we were looking not only at in-hospital survival but five-year survival," said Wen Cheng, the cardiothoracic surgeon who led the study.
The study found that patients have significantly better long-term outcomes when surgeons place a bypass graft to all the territories of the heart that have significantly blocked arteries.
Taking into consideration the various risk factors from one group of patients to another, incomplete revascularization clearly increased the chance of death within five years of bypass surgery.
In fact, there was a 70 percent increase in the chance of death from any cause, and an 85 percent increase in the chance of dying of a cardiac-related disorder if a patient received incomplete revascularization.
" The benefit of complete revascularization makes intuitive sense, and this study supports that. But many of the procedures that are being performed today result in only incomplete revascularization," Cheng said. " According to one recent study, for example, complete revascularization was achieved in only 74 percent of patients undergoing percutaneous intervention ( balloon angioplasty and stenting ) and in only 82 percent of those undergoing coronary artery bypass surgery."
The Cedars-Sinai study also found that long-term survival increased when arteries, not veins, were used in grafting. Especially in the early days of bypass operations, saphenous veins from the legs were used to replace blocked coronary arteries. But in the past few years, many surgeons have abandoned veins for arteries of the chest and arm.
" It is much easier to harvest and work with veins, but, unfortunately, veins do not last forever," said Cheng. "Arteries are naturally better able to carry blood under arterial pressure than veins, and while arterial grafting is technically more difficult to accomplish, requiring a higher level of skill, it was the best choice for our patients."
Results of the study are based on a review of the quality assurance database for patients who underwent coronary artery bypass grafting between January 1998 and January 2000 at Cedars-Sinai.
" In this study, we tried to look at every possible factor – individually and in combination with hundreds of other factors – that might affect whether a patient lives or dies in five years," Cheng said. " Many things did not matter one way or another, but several factors did make a significant difference. Notably, patients who had complete revascularization did better than those who had incomplete revascularization, and patients who had arterial grafting did better than those who had venous grafting. Based on these findings, we encourage heart surgeons to try to graft all affected territories and to use arterial grafts whenever possible."
Source: Cedars-Sinai Medical Center, 2005
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