[Aortocoronary bypass. Intermittent clamping of the aorta versus cardioplegia]. / Bypass aorto-coronário. Clampagem intermitente da aorta versus cardioplegia.

STUDY OBJECTIVE: Cardioplegia is the standard method of myocardial protection during aorto-coronary bypass surgery. However, there are other alternatives which the authors intend to test. DESIGN: Forty consecutive, non-selected cases of coronary artery bypass surgery done with intermittent aortic crossclamping (Group A) are compared with the 40 preceding consecutive cases where cardioplegia was used (Group B). PATIENTS: The mean age of the patients of group A was 57.5 years (range 42-69 years) and that of group B was 57.1 years (range 39-76 years). Patients of group A had an incidence of previous myocardial infarct of 42.5% against 65.0% in group B. Chronic angina led to surgery in 33 cases of group A and in 32 of group B. The remainder (18.8%) had unstable angina. INTERVENTIONS: The mean number of grafts per patient was 2.9 in group A and 3.2 in group B. Internal mammary arteries were used in most patients of both groups, with 61 anastomoses in group A (1.5/patient) and 57 in group B (1.4/patient). The mean ischaemic time per graft was 7.4 min (range 5.5-11 min) in group A and 15.6 min (8.5-22 min) for group B. MAIN RESULTS: Serial analysis of myocardium-specific serum enzymes and the CPK-MB/total CPK ratio has not evidenced perioperative infarction in any patient of either group. Although enzyme levels were slightly higher in group A, the difference has not reached statistical significance. However, the electrocardiograms have shown one perioperative infarct in each group. Vasodilators were generally used in the 2 groups, for a mean of 16.8 hours, while inotropic drugs were required in only 4 cases of group A and 3 of group B. There has been no hospital mortality in either group. CONCLUSIONS: These results, in a series of non selected patients, demonstrate that intermittent crossclamping may be an acceptable alternative method of myocardial protection during aorto-coronary bypass surgery thus made simple, quick and secure.

[Surgery of the coronary vessels in the elderly]. / Cirurgia das coronárias na 3.a idade.

STUDY OBJECTIVE: The rising numbers of elderly patients with occlusive coronary artery disease amenable to surgical correction prompted us to reevaluate the benefits and risks of aorto-coronary bypass in these patients. PATIENTS: In the five-year period, from June 1980 through May 1985, 293 patients 65 years old and older (mean 69.1 years) and with a male: female ratio of 4:1, were subjected to aorto-coronary bypass. RESULTS: Operative mortality was 4.8%, higher amongst 71 patients who had endarterectomy (8.5%) and those who had concomitant valve replacement (7.7%), but lower (2.5%) in the 99 patients who had only saphenous vein grafts (p less than 0.05). The survivors were followed for three to eight years (mean 4.9 years), with a cumulative follow-up of 1.005 patient-years. Late mortality was 4.6%/patient-year (46 patients), higher in patients with valve replacement (6.0%/patients-year; p less than 0.05), but lower in patients with internal mammary artery grafts (2.6%/patient-year). Late mortality was cardiac-related in 45.6% of the cases (21/46). Two patients were reoperated upon (0.2%/patient-year) and other two had percutaneous balloon angioplasty. Thirty six patients (12.9%) had recurrent angina during the period of follow-up, but the incidence was 20% in those who had only vein grafts (p = NS). Nine patients had myocardial infarction (0.9%/patient-year) of which six (67%) were fatal. In actuarial terms, 80% of the patients survived and 95% were free from myocardial infarction after six years. CONCLUSIONS: As in younger patients, coronary surgery in the elderly patient leads to improved life quality and survival. This study appears to confirm the superiority of internal mammary artery grafts also in the old patient.