Aortocoronary bypass or stenting?
What method should be preferred planning treatment of a patient with a cardiovascular disease: coronary angioplasty and stenting or aortocoronary bypass (CABG)? The leading experts in the field of cardiology and cardiac surgery ask themselves this question often enough.
The following article describes some large-scale studies on this topic.
Angioplasty and CABG: definition
Coronary angioplasty and stenting
Aortocoronary bypass (CABG)
|Coronary angioplasty and stenting are the most common procedures in modern invasive cardiology. During angioplasty, atherosclerotic deposits are removed on the walls of the coronary arteries, supplying blood to the heart muscle (myocardium). After the angioplasty in order to prevent the restenosis (renarrowing) of the coronary arteries, doctors install a stent (supporting skeleton) in its lumen. Stenting is considered to be an extremely effective treatment for patients with coronary heart disease (CHD) and acute myocardial infarction (heart attack). This procedure is performed within the framework of catheterization of the vessels and does not belong to the category of surgical interventions.||Aortocoronary bypass surgery is a heart operation, during which a circulatory path of blood supply (bypass) is created around the stenotic portion of the coronary artery. For this purpose a shunt-segment of the blood vessel is used. His donor is the patient himself: a shunt is formed from a vessel of the chest or lower limb. One of the main advantages of shunting is the reliability of the alternative way (bypass) of the blood supply to the myocardium: shunts have a long viability and retain their patency for a long time|
Comparison of operations: results of clinical trials
During the last three years, several important scientific papers have been published summarizing the results of clinical studies conducted in the group of patients with cardiovascular diseases studying the efficacy and safety of various treatment modalities.
The results of the first research called Syntax were published in the journal Lancet in February 2013. The study was performed in a group of 1,800 patients with stenosis of three major coronary arteries or stenosis of the common left coronary artery. Half of patients underwent coronary artery bypass grafting, the second half was treated by the new-generation stent installation with a drug coating. In terms of the severity of the clinical condition, both groups were identical. Based on the results of a 5-year observation, the researchers came to the following conclusions:
The overall condition in all parameters among the patients with prolonged stenosis of coronary arteries after coronary artery bypass grafting is assessed as more satisfactory than among the patients, undergoing stenting
The rates of total mortality and mortality associated with cardiovascular disease among the patients, undergoing aortocoronary bypass surgery, were lower
The number of repeated myocardial infarctions among the patients, who underwent aortocoronary bypass surgery, was less
After aortocoronary shunting, there was less need for further invasive cardiac manipulation
No significant differences in the efficacy of both methods were observed among the patients with heart disease of mild to moderate severity were observed
The data collected during the second research (Freedom) were published in the New England Journal of Medicine (NEJM) in December 2012. This time, a comparative analysis of the effectiveness of stenting using new-generation stents and aortocoronary shunting was performed among patients with diabetes mellitus. It is well known that stenting in patients with diabetes is often accompanied by restenosis of the coronary arteries. The reason for this phenomenon lies in the abnormalities of the vascular wall, which develop due to diabetes mellitus. Until now, there was no reliable information on the effectiveness of the use of new-generation stents in this category of patients. The results of the Freedom study have brought a final clarity to this issue. Five years of follow-up for two groups of patients 950 people each, were carried out. The scientists came to the following conclusions:
All patients were diagnosed with diabetes mellitus in the same degree of severity
The mortality rate in the group of patients who underwent stenting was 30% higher than the similar index in the group of patients after coronary artery bypass grafting
The number of myocardial infarctions after stenting was twice higher (13.9% compared to 6%)
The need for repeat procedures was observed among 13% of patients after stenting compared to 5% of patients after aortocoronary bypass surgery
At the same time, the number of strokes in the group that underwent stenting was lower: 2.4% compared to 5.2%
The researchers concluded that among patients with diabetes, coronary artery bypass grafting is a more effective and safe procedure compared with stenting, even with the use of drug-eluting stents.
The third research (Ascert), the results of which were published in March 2012 in NEJM, is rightly considered to be one of the most wide-ranging in the history of cardiology and cardiac surgery. Its organizers used the information base of American professional communities of cardiologists and thoracic surgeons (ACC – American College of Cardiology, STS – Society of Toracic Surgeons) for 2004-2008. The information base contains data on more than 2 million patients in the United States, who during the reporting period had either stent implantation or aortocoronary bypass surgery. The final sample included 190 000 clinical cases. Patients were monitored for 4 years. Postoperative mortality in the group after coronary artery bypass grafting was 16.4%, in the group of patients who underwent stent placement it was 20.8%. In other words, mortality among patients who had aortocoronary bypass surgery as a treatment technique was 21% lower compared to those who had stent implantation.
Combination of coronarography with angioplasty and stenting is undesirable
In most situations, according to leading experts, it is undesirable to combine coronarography, which is a diagnostic procedure, with treatment manipulations: angioplasty and stenting. If coronary angiography diagnoses coronary artery stenosis, but the patient's condition does not require emergency medical care, it is not advisable to immediately switch to angioplasty and stent placement. The decision to choose a method should be taken collectively, after a thorough discussion of all aspects of the procedure, with compliance with the rights of the patient to participate in the treatment process and obtaining informed consent.
Currently, American and European associations of doctors specializing in the treatment of cardiovascular pathologies recommend to use in the clinical practice the concept of a cardiac team – the Heart Team. The team should be formed from both cardiologists and cardiac surgeons, and each case should be examined on an individual basis. This is how the strategic decisions are made in the private clinic "Herzliya Medical Center" when it comes to treating patients with serious cardiovascular diseases.