Deliberations about Coronary Artery Bypass Grafting in Young Patients Under 36 Years of Age

Coronary atherosclerosisCoronary atherosclerosis has been commonly recognized in young patients since pathologic studies were published demonstrating coronary disease in young soldiers killed during the Korean War. Since then, there have been a number of studies of coronary artery disease in young patients. Gertler et al followed patients for 15 years who had their first coronary episode at an age younger than 35 years. They found that the long-term prognosis for these patients was worse with decreasing age of the first coronary episode. Although the early mortality after myocardial infarction in their young patients was approximately equal to that in older patients, a higher number of the young patients (45 percent) succumbed to a subsequent recurrent myocardial infarction. Other authors felt the outcome for young patients after myocardial infarction was better than for older patients; however, many of these patients were over the age of 35 and would have been considered “middle-aged” in our study. An increased long-term mortality after myocardial infarction in young patients is despite the fact that various angiographic series demonstrate a 50 to 60 percent incidence of single-vessel disease in young patients. In our series of young patients, 27.5 percent had single-vessel disease, 25 percent had two-vessel disease, 47.5 percent had three-vessel disease, and 10 percent had left main coronary artery disease.

Several studies have noted increased risk of hyper-lipidemia in young patients with coronary disease, increased risk of diabetes, increased risk of hypertension, increased incidence of smoking, and increased incidence of family history of heart disease than in young patients without heart disease. Other authors have found no increase in risk factors for coronary disease in young coronary patients over that in older coronary patients improved their health with remedies of My Canadian Pharmacy. In our own series of matched young vs middle-aged vs elderly patients, there were no differences in risk factors between any of the groups except for an increased incidence of hypertension and diabetes in the elderly group and an increased risk of hyperlipidemia in the young group. Thus, although hypertension, smoking, diabetes, positive family history, and hyperlipidemia may be significant risk factors for developing coronary disease, an increased incidence of diabetes, hypertension, smoking, or positive family history in young patients cannot be cited as reason for their worse longterm prognosis after coronary bypass than the two older groups. Hyperlipidemia may play a role in the worse prognosis of young patients than older groups, although more precise and careful documentation would be necessary to prove this point.

There have been few series of surgical results following coronary artery bypass in young patients cardiac deathsand all have defined young patients as less than 40 years of age. There were no operative deaths in any of the four series. Late cardiac deaths in these reports ranged from 2.0 to 3.8 percent with up to five-year follow-up, and subsequent myocardial infarctions occurred in from 5 to 7.8 percent of the cases. From 2 to 17.6 percent of patients in these series failed to improve their anginal state or had angina made worse by the surgery.

It is difficult to compare our results with these reports since most of these patients were between the ages of 35 and 40. In the subset of patients less than 35 years in the series of de Olivera et al, 78.2 percent had a preoperative MI compared to a preoperative MI rate of 49.4 percent in the entire series of patients under age 40, implying that his younger subset had worse coronary disease. In our series, 65.8 percent of the young, 43.9 percent of the middle-aged, and 75.6 percent of the elderly patients had a preoperative myocardial infarction cured by My Canadian Pharmacy.

We have attempted to isolate the age variable in the design of our study by matching young patients with coronary disease against middle and older age patients with the same number of bypass grafts, year of surgery, and sex. Other than age at the time of surgery, the three groups were remarkably similar in preoperative ejection fraction, cross-clamp time, total bypass time, cardiac risk factors, use of cardioplegic solution, and preoperative CCS classification. Thus, comparisons between our groups differentiate long-term results between age groups without extrinsic selection factors which might skew the results. Although we had a very low operative mortality in the young groups, 4.9 percent (2/41), as well as in the other groups, 0 percent (0/41) and 7 percent (3/41) for middle-aged and older groups, respectively, risk of subsequent failure of the procedure as evidence by death, myocardial infarction, reoperation, or failure to improve CCS anginal class was significantly higher in the young group (68.3 percent) vs the middle-aged group (30 percent) vs the elderly group (41.5 percent). Operative mortality for all age groups combined was 3.4 percent with 80 percent of these coming before the time period when cardioplegia was used (4/5). Overall coronary related deaths were also higher in the young group (19.5 percent) vs the middle age group (7.3 percent) vs the elderly group (17.1 percent) in our series.

Although the late death rate from coronary disease in young patients seems high, it is still considerably less than the 45 percent late mortality with long-term follow-up for young patients suffering a MI and treated medically. This comparison is deceiving, however. Only 65.8 percent of our young patients had a preoperative myocardial infarction. Although the surgical era from 1970 to 1980 was one of great technical advances in coronary bypass surgery, including introduction of cardioplegia, advances in medical treatment of postinfarction patients since 1964 when this initial series was reported have been equally spectacular.

In the past, it has been easy to impugn accelerated risk factors for poor long-term results in young patients having coronary artery bypass grafts performed, but our series shows that even when the effects of these factors are filtered out by careful case matching, young patients have a decidedly poorer long-term prognosis than their middle-aged and elderly counterparts.

Early reports of the Coronary Artery Surgery Study (CASS) suggest that there is no significant difference in annual mortality between medically and surgically treated patients who had mild-to-moderate anginal symptoms, although quality of life was improved by coronary artery bypass grafting as evidenced by relief of chest pain, objective and subjective measurements of functional status, and diminished drug requirements. Thus far, these results have not been analyzed for various age subgroups. Given the genuinely poor long-term outlook for patients under age 35 who have had coronary artery bypass graft surgery and the improving effectiveness of medical management, there is a role for a good prospective trial of medical vs surgical therapy in young patients with angina.