Risk factors in coronary artery bypass surgery for patients 40 years of age and younger

Profile of Coronary Artery Bypass Surgery in United Arab Emirates: Dubai Hospital Experience

Although coronary artery bypass surgery has become a common procedure, there were no data available regarding this type of surgery in the United Arab Emirates. Therefore, we undertook this retrospective study of the first 522 consecutive patients undergoing coronary artery bypass graft surgery between October 1992 and July 1997. The mean age was 49.1 years at operation with a 97.1% male predominance. Patients of Asian origin accounted for 75.8%, Arabs 22.4%, and Europeans 1.7%. Chronic stable angina was the most frequent presenting symptom (70.4%) and 62.1% patients had at least one prior myocardial infarction. There was a 44.6% incidence of hypertension and 32.9% of patients were diabetic. Other prominent risk factors were smoking (55.7%), hyperlipidemia (53.9%), and family history of ischemic heart disease (10.7%). Left main coronary artery obstruction was evident in 6.5% of patients. An average of 3.4 grafts per patient were performed using reverse saphenous vein and endarterectomies were needed in 2.2%. The early mortality rate in elective cases was 2.4%. This study suggests that in spite of a high incidence of multiple risk factors, our patients tolerated coronary artery bypass surgery well. Our findings highlight the trend towards more urgent operations and the decreasing age of patients with severe coronary artery disease.

Left internal mammary artery improves 5-year survival in patients under 40 subjected to surgical revascularization

BACKGROUND

The population of young patients under 40 requiring coronary bypass surgery is characterized by an extremely and unusually rapid progression of coronary heart disease. The aim of the present study was to assess the clinical status and quality of life in these patients after surgery in relation to the type of conduit used to revascularize the left anterior descending artery (LAD).

METHODS

One hundred seventeen patients under 40 (range, 30-40 years) underwent coronary artery bypass grafting (CABG) at our institution between 1991 and 1999. Ninety-one patients received LIMA to LAD graft (group A), and in 26 patients the saphenous vein was used to graft this vessel (group B). Seventy-eight patients (63 in group A and 15 in group B) were assessed after a mean time of 71 +/- 26 months. They were asked to fill out a questionnaire aimed at their subjective assessment of their quality of life as compared with their preoperative status.

RESULTS

Five-year actuarial survival was higher in patients with LIMA to LAD graft (log rank test: P < .004). The functional status of patients in group B was significantly worse in comparison to group A: respectively, CCS 2.2 +/- 1.1 versus 1.5 +/- 0.7; (P = .02), NYHA 2.2 +/- 1.1 versus 1.3 +/- 0.5; (P = .002). Patients in group B more frequently required reinstitution of nitroglycerine treatment (93% versus 56%; P = .025). We failed to show differences between the 2 groups as far as subjective quality of life is concerned. In summary, 63% of patients perceived it to be worse, 29% to be better, and 8% felt it had not changed.

CONCLUSION

The use of LIMA is crucial in patients undergoing CABG under the age of 40 in order to achieve the best possible surgical results. Quicker recurrence of coronary disease symptoms is observed when a vein is used to graft the LAD. It may reflect an earlier progress of atherosclerosis in venous grafts.

Angiotensin I-converting enzyme insertion/deletion polymorphism and cardiac mortality and morbidity after coronary artery bypass graft surgery

STUDY OBJECTIVES

This study was designed to evaluate whether the insertion (I)/deletion (D) polymorphism of the angiotensin I-converting enzyme (ACE) gene is associated with mortality and cardiac morbidity after coronary artery bypass graft surgery (CABG).

METHODS AND RESULTS

The ACE I/D genotype was determined in 249 consecutive patients who underwent CABG. Follow-up information (after 2 years) was obtained in 247 patients (99.2%). The primary end point was total mortality; the secondary end point was mortality from cardiac reasons, or the need for myocardial revascularization (coronary angioplasty or recurrent CABG) during follow-up. At follow-up, total mortality was 9.7% (all patients). None of the 51 patients with the ACE II genotype, 14 of 125 patients with the ACE ID genotype (11.2%), and 10 of 71 with the ACE DD genotype (14.1%) died during follow-up (p < 0.05). The ACE DD genotype, older age, diabetes mellitus, decreased left ventricular ejection fraction, and lack of internal mammary artery graft were independently related to an increased mortality after CABG. The incidence of the secondary end point was 14.5% (all patients): ACE II, 5.8%; ACE ID, 9.4%; ACE DD, 30.3% (p < 0.05). The ACE DD genotype and the presence of a left main coronary artery stenosis >or= 50% were independent predictors for the secondary end point.

CONCLUSION

The ACE DD genotype is associated with increased midterm mortality and cardiac morbidity after CABG.

Is left main coronary artery stenosis a risk factor for early mortality in coronary artery surgery?

It is accepted universally that the treatment of critical left main coronary artery (LMCA) stenosis is surgical revascularization. This study was designed to evaluate critical LMCA stenosis as a risk factor in coronary artery bypass surgery. We compared the surgical results of 760 patients with critical LMCA disease, including 58 cases who were operated under emergency conditions (LMCA-em) and 702 patients who were operated electively (LMCA-el), with randomly chosen 707 coronary bypass patients (CONT-el) without LMCA disease, but who had double- or triple-vessel disease. Another group of patients (n = 99) who were operated on under emergency conditions (CONT-em) but without LMCA disease were also compared with the corresponding groups. The mortality of LMCA-em group and CONT-em group was markedly higher from the other two groups. Univariate analysis revealed that female gender, older age, presence of diabetes mellitus, poor left ventricular function, and the presence of unstable angina were major risk factors for fatal outcome in LMCA-el and CONT-el groups. Age was also a risk factor in LMCA-em group, as well as unstable angina pectoris. The coexistence of critical right coronary artery disease did not affect the early outcome in both groups with LMCA lesions. In the multivariate analysis, critical LMCA disease was not a risk factor for mortality. Logistic regression analysis revealed diabetes [odds ratio (OR): 3.66], poor left ventricular function (higher left ventricle end-diastolic pressure, OR: 1.08), and emergent operations (OR: 5.09) were risk factors for early mortality. Patients with LMCA disease should have surgery promptly for favorable results, because emergency conditions have higher mortality rates.