Long-term clinical and hemodynamic studies after ventricular aneurysmectomy and aorta-coronary bypass.

Late clinical and hemodynamic evaluations in 18 patients with ventricular aneurysmectomy and aorta-coronary bypass are presented. Tne patients had significant obstructive lesions in two major vessels (55 per cent), and 6 had extensive three vessel disease (33 per cent). In 13 patients, 21 aorta-coronary saphenous bypass grafts were performed in addition to aneurysmectomy. The operative mortality rate was 11 per cent. One patient died suddenly 5 months after the operation (one year mortality rate 17 per cent). The 15 surviving patients have been followed up for 12 to 41 months (average 24 months). Clinical results were considered excellent in 2 patients who have been asymptomatic (Class I, N.Y.H.A.). Nine others were considered to have good clinical results (Class II). Five patients have continued to have congestive heart failure and angina on minimal effort (Class III or IV). Six of the 11 patients considered to have excellent or good results underwent postoperative hemodynamic studies 6 to 34 months after the operation. A significant increase in cardiac index was documented in all 6 patients. Paradoxic movement was not detected in any of the postoperative ventriculograms. Five of the seven venous grafts inserted were patent. Elevated left ventricular end-diastolic pressure (LVEDP), low cardiac index, and a persistent dyskinetic area in the left ventricle were found in 2 patients considered to have poor clinical results. Clinical and hemodynamic evaluations have shown a significant improvement in most patients surviving ventricular aneurysmectomy. However, postoperative systemic embolism, myocardial infarction, progression of coronary artery disease, transient cerebral ischemic attacks, graft occlusion, arrhythmias, and mitral regurgitation in previously prolapsed mitral valve leaflets account for progressive disability and limited activity after a successful operation.     

Left ventricular aneurysm. Preoperative risk factors and long-term postoperative results.

The results of operative treatment of postinfarction left ventricular aneurysm in 169 patients undergoing operation since 1970 are analyzed in this report. Maximum follow-up extended to 7 year (average 2.9 years). Average patient age was 56 years (range 34 to 82 years). Nearly all patients (94%) had left anterior descending coronary artery disease with anterior aneurysm formation and 73% had multivessel disease. Sixty-eight percent of patients underwent aorta-coronary bypass grafting (ACBG) and/or mitral valve replacement (MVR) concomitantly with aneurysmectomy. The over-all operative mortality rate was 17.8%. Preoperative factors that correlated significantly (p less than 0.05) with increased operative risk reflected primarily the quality of left ventricular function, and included functional classification, cardiac index, contractile function of residual myocardium not involved by aneurysm, and mitral regurgitation. Patients whose primary preoperative disability consisted of angina pectoris (42 patients) exhibited significantly higher over-all survival rates (actuarial 5 year survival 75%) than those undergoing operation because of congestive heart failure (86 patients) or ventricular tachyarrhythmias (38 patients), whose 5 year survival rates were 52 and 57%, respectively. Concomitant ACBG (+/- MVR) was associated with a higher operative mortality rate than aneurysmectomy alone (21.1 versus 10.9%), but late postoperative attrition was similar. The over-all 5 year survival rate, including operative death, was 60%, and 90% of surviving patients were in Functional Class I or II at follow-up evaluation. We conclude from this analysis that the long-term prognosis of patients with symptomatic postinfection left ventricular aneurysms, although determined importantly by preoperative left ventricular function, is enhanced by surgical treatment.     

Long-term result of aorto-coronary bypass surgery

Four hundred and nineteen cases of aorto-coronary bypass surgery which were operated at the Juntendo University Hospital for last 8 years were reviewed with respect to operative, hospital and late mortality, and survival. Isolated coronary bypass (371 pts) had 2.7 per cent of operative mortality, 1.9 per cent of hospital mortality, 1.3 per cent of late mortality and 94.1 per cent of survival rate postoperative follow-up ranged up to 8 years (average 3.51 years). Late mortality was 2.6 per cent in the group of left main trunk lesion, 1.3 per cent in the group of patients over 60 years old, 0.7 per cent in single bypass group, 1.2 per cent in double bypass and 6.7 per cent in triple bypass group. Patients complaining of unstable angina showed significantly higher operative, hospital and late mortality compared with patients with stable angina. Cardioplegia for an intraoperative myocardial protection provided better operative result, however, there is no significant difference in late mortality between potassium-induced and potassium-magnesium-induced cardioplegia. Intraoperative myocardial protection using lidocaine, aprotinin and coenzyme Q10 is important to improve surgical results in patients with either left main trunk lesion or age over 60. Successful treatment of 5 patients with evolving or acute myocardial infarction was experienced. These results suggest that aorto-coronary bypass surgery is accepted as a safe and important treatment for ischemic heart disease.     

Ischemic cardiomyopathy: medical versus surgical treatment.

The natural history of patients with ischemic heart disease and depressed left ventricular function is dismal, and medical therapy has failed to alter its course. To assess the results of aorta-coronary bypass grafting in patients with coronary artery disease and decreased left ventricular ejection fraction (LVEF less than or equal to 0.3), we compared 70 medically treated patients to 46 patients having aorta-coronary bypass grafting. The duration of follow-up was 6 to 72 months (mean 19 months). All patients had angina pectoris. Congestive heart failure was present in 56 percent (39/70) of the medical and 43 percent (20/46) of the surgical group. The medical group had a mean LVEF of 0.20 and a mean left ventricular end-diastolic pressure (LVEDP) of 29 mm. Hg. The surgical group had a mean LVEF of 0.21 and a mean LVEDP of 24 mm. Hg. Three vessel disease was found in 60 percent (42/70) of the medical group and 83 percent (38/46) of the surgical group. The operative mortality rate in the surgical group was 4 percent (2/46). There were four late deaths. The 2 year actuarial survival rate for medical and surgical groups was 47 percent and 83 percent, respectively. Significant improvement in angina pectoris and/or congestive heart failure was found in 16 percent (11/70) of medically treated patients and 95 percent (38/40) of the surgically treated patients. Aorta-coronary bypass grafting can be performed in patients with poor left ventricular function with a low operative mortality rate, relief of angina pectoris, and improvement in symptoms of congestive heart failure.     

Effects of coronary bypass surgery on the electrical activity of revascularized myocardium. Immediate and early postoperativeobservations.

The effect of myocardial revascularization on bipolar epicardial electrograms was recorded with fixed wire electrodes from revascularized left ventricular sites and from control sites on the right ventricle. Studies were performed during and after surgery in 19 patients undergoing aorta-coronary bypass grafting for occlusive coronary artery disease and in 6 additional patients having aortic valve replacement for isolated aortic valve disease. In the latter 6 patients, neither left nor right ventricular electrogram voltage changed immediately following aortic valve replacement; however, left ventricular electrogram voltage gradually decreased for 5 days postoperatively. In the 19 patients with coronary artery disease, electrogram voltage in the revascularized area increased immediately following coronary bypass grafting (+40 to +300 per cent) in 13 patients (68 per cent) and immediately decreased (-20 to -70 per cent) in 6 patients (32 per cent). In 5 of the patients showing immediate increases, temporary occlusion of the bypass grafts for 3 minutes during surgery resulted in a decrease of electrogram voltage in the distribution of the occluded bypass, followed by return to preocclusion levels after release. Postoperative monitoring of electrogram voltage for 5 days in all patients with coronary artery disease revealed that the electrogram voltage in the revascularized area decreased to or below control levels in 16 patients (84 per cent) and remained increased in 3 patients (16 per cent). These observed changes did not correlate with preoperative hemodynamics, number of grafts, graft flow rate, aortic cross-clamp time, cardiopulmonary bypass time, and the early postoperative course. These preliminary observations suggest that coronary bypass grafting does affect the electrophysiological state of the revascularized myocardium. However, the mechanism by which it occurs and its clinical implications remain to be determined.     

Surgical revascularization in patients with poor left ventricular function: on- or off-pump?

BACKGROUND: Patients with left ventricular dysfunction and low ejection fraction (EF) are at high-risk of complication and mortality after coronary artery bypass grafting (CABG). The potential success of off-pump CABG in this high-risk population has yet to be determined. The purpose of this study is to compare the outcome of off-pump coronary artery bypass (OPCAB) and conventional coronary artery bypass (CCAB) in patients with poor left ventricular function, all from a single institution. METHODS: Data on patient demographics, preoperative risk factors, operative and postoperative outcomes were collected retrospectively on all patients having undergone isolated CABG between January 1, 1998, and October 31, 2001. RESULTS: A total of 77 patients (31 OPCAB/46 CCAB) were identified as having an ejection fraction (EF) of < or = 0.35. Of these, 52 had EF < or = 0.30 (21 OPCAB/31 CCAB) and 31 patients had EF < or = 0.25 (10 OPCAB/21 CCAB). Operative mortality was 3.2% after the OPCAB procedure versus 10.9% for the CCAB (p = 0.39). Use of intraaortic balloon pump (6.5%) was rarely required. The OPCAB procedure resulted in significantly less requirement for blood transfusions (p < 0.05), fewer distal anastomoses per patient (p < 0.01), and a higher incidence of atrial fibrillation (p < 0.05) compared with CCAB. CONCLUSIONS: Patients with poor left ventricular function may undergo surgical revascularization using off-pump technique with relatively good results and low mortality levels. The lower number of grafts performed on the off-pump procedure did not seem to affect clinical outcomes.     

Prophylactic Use of Intra-aortic Balloon Pump in Aortocoronary Bypass for Patients with Left Main Coronary Artery Disease

Aortocoronary bypass surgery in patients with left main coronary artery disease is reported to have an operative mortality of between 1.4 and 39%. It is generally accepted that the operative mortality in this group of patients is considerably greater than in routine bypass candidates, presumably due to the large amount of myocardium threatened by a single lesion. In an effort to preserve threatened left ventricular myocardium, intra-aortic balloon pumping was instituted prophylactically prior to sternotomy in 20 consecutive patients with left main coronary artery disease (luminal narrowing greater than 50%). Sixty per cent of these patients had New York Heart Association Class IV angina, 25% had Class III, and 15% Class II. Fifty per cent of the patients in this group presented with unstable angina. Operative patients requiring left ventricular aneurysmectomy and/or valve replacement, were excluded. No operative deaths have been encountered in 20 consecutive patients managed in this manner. One patient displayed signs of myocardial infarction in the postoperative period. Correctable peripheral vascular ischemic complications of pump insertion were encountered in three patients. Preliminary results from this ongoing study support the hypothesis that prophylactic intra-aortic balloon pumping is a low risk procedure that should be utilized routinely in aortocoronary bypass surgery for left main coronary artery disease.     

The characteristics of coronary artery revascularization in aged patients

This study was undertaken in order to clarify the clinical characteristic features and surgical results of coronary artery bypass grafting (CABG) in patients over 65 years of age (group III, n = 43). These patients were compared with 2 other groups of patients, one aged between 50 and 59 years (group I, n = 88) and another aged between 60 and 64 years (group II, n = 54), with respect to mortality, morbidity and late survival. CABG was performed with the saphenous vein under cold K-Mg-cardioplegia with systemic hypothermia. The hospital mortality was 2.3, 3.7, and 4.7 per cent in groups I, II and III, respectively, although no operative mortality was noted in any group. The number of coronary artery lesions increased with age, however, the left ventricular ejection fraction was relatively better preserved in the aged patients than in the younger ones. The 5-year survival rates were 93.4, 95.1 and 96.9 per cent in groups I, II and III, respectively, with most of the late deaths occurring within a year after CABG in each group. In the aged patients, postoperative functional recovery was delayed in the liver and kidney, and postoperative psychosis was not infrequent. The results of this study, indicating a low operative mortality and satisfactory late survival rate, thus strongly support CABG for the aged. Nevertheless, the prevention of postoperative complications is also extremely important for reducing hospital mortality.     

Early and long-term results of coronary artery bypass grafting in dialysis patients

BACKGROUND: Dialysis patients frequently present with debilitating coronary artery disease but are regarded as challenging patients for coronary artery bypass grafting. METHODS: The operative, early postoperative, and late results of 44 dialysis patients undergoing coronary artery bypass grafting from 1984 to 1997 were retrospectively reviewed. RESULTS: Compared with patients in The Society of Thoracic Surgeons database who underwent coronary artery bypass grafting, only cerebrovascular accident and postoperative cardiac arrest occurred more frequently in dialysis patients. However, 73% experienced some type of complication. Operative mortality was 11.4%. Decreased left ventricular ejection fraction and severe distal disease were predictive of increased operative mortality. New York Heart Association angina class fell from 2.8 to 1.5, and New York Heart Association congestive heart failure class fell from 2.6 to 1.8. Overall quality-of-life scores did not improve; however, walking distances remained consistently improved. Actuarial survival at 5 years was 32.0%+/-12.0%. Five-year survival was 0% for smokers and 83.6%+/-7.6% for nonsmokers (p = 0.0142). Causes of late death were myocardial infarction (4), sepsis (1), subdural hematoma (1), stroke (1), and unknown (6). CONCLUSIONS: Coronary artery bypass grafting should be avoided in dialysis patients with severe diffuse disease. A smoking history is associated with poor outcome. Coronary artery bypass grafting in dialysis patients is associated with a higher incidence of complications but can be performed with an acceptable operative mortality and is associated with good symptomatic relief of angina and heart failure.     

The characteristics of coronary artery revascularization in aged patients

This study was undertaken in order to clarify the clinical characteristic features and surgical results of coronary artery bypass grafting (CABG) in patients over 65 years of age (group III, n=43). These patients were compared with 2 other groups of patients, one aged between 50 and 59 years (group I, n=88) and another aged between 60 and 64 years (group II, n=54), with respect to mortality, morbidity and late survival. CABG was performed with the saphenous vein under cold K-Mg-cardioplegia with systemic hypothermia. The hospital mortality was 2.3, 3.7, and 4.7 per cent in groups I, II and III, respectively, although no operative mortality was noted in any group. The number of coronary artery lesions increased with age, however, the left ventricular ejection fraction was relatively better preserved in the aged patient than in the younger ones. The 5-year survival rates were 93.4, 95.1 and 96.9 per cent in groups I, II and III, respectively, with most of the late deaths occurring within a year after CABG in each group. In the aged patients, postoperative functional recovery was delayed in the liver and kidney, and postoperative psychosis was not infrequent. The results of this study, indicating a low operative mortality and satisfactory late survival rate, thus strongly support CABG for the aged. Nevertheless, the prevention of postoperative complications is also extremely important for reducing hospital mortality.     

The assessment of function of left ventricle and patency of aorta-coronary bypass after operation. A study of systolic time intervals.

The effect of aorta-coronary bypass surgery on left ventricular function was evaluated in 39 patients by cardiac catheterization and recording of the systolic time intervals (STI) before and an average of 4.5 months following myocardial revascularization. All patients were in sinus rhythm, had normal QRS intervals on the electrocardiogram, and had taken no medication for at least 3 weeks prior to the study. The STI was unchanged postoperatively in patients with the following characteristics: freedom from angina; heart rate not more than 15 beats greater than the preoperative level; all grafts patent; and no progression of disease in coronary arteries. Deterioration in left ventricular function after operation as represented by shortened left ventricular ejection time, (LVET) prolonged pre-ejection period (PEP), and increased ratio of PEP/LVET was found in patients with the following characteristics: persistent angina; heart rate more than 14 beats faster than the preoperative level; occlusion of any grafts; progression of disease in the coronary arteries; evidence for postoperative myocardial infarction. Worsening of left ventricular performance as determined by STI was more apparent in patients with occluded grafts and no collateral circulation than in those with occluded grafts and collateral circulation which may have offered protection against ischemia. These investigations supported the use of STI in assessing changes in left ventricular function after coronary bypass and, by inference, in assessing the status of the graft.     

Valvular heart disease

Reoperation for valvular heart disease has been associated with a higher operative mortality than primary operations, especially in patients who had multiple prior operations. We have analyzed the 226 consecutive patients who underwent valve replacement. These involved 163 primary operations, 52 first reoperation, and 11 second/third reoperations. Preoperative left ventricular dysfunction was more severe, and operation time and cardiopulmonary bypass time were significantly greater according to the number of operations, associated with a greater amount of intraoperative blood loss. The operative mortality after a second/third reoperation was 27.3%, which was significantly higher than that after primary operation (6.7%) (p < 0.05), and that after first reoperation (5.8%) (p < 0.05). Seven (64%) patients who underwent a second/third reoperation had poor preoperative left ventricular function (%FS < 25%), and 5 (71%) of these required postoperative mechanical supports, and 3 (60%) of the 5 patients died of low output syndrome. We have found that poor preoperative left ventricular function and the duration on cardiopulmonary bypass, but not the number of reoperation were correlated with operative mortality. Continued efforts should be directed to decrease the mortality for multiple reoperative valve surgery.     

Valvular heart disease. A comparative study of results after primary operation, reoperation, and after multiple reoperation.

Reoperation for valvular heart disease has been associated with a higher operative mortality than primary operations, especially in patients who had multiple prior operations. We have analyzed the 226 consecutive patients who underwent valve replacement. These involved 163 primary operations, 52 first reoperation, and 11 second/third reoperations. Preoperative left ventricular dysfunction was more severe, and operation time and cardiopulmonary bypass time were significantly greater according to the number of operations, associated with a greater amount of intraoperative blood loss. The operative mortality after a second/third reoperation was 27.3%, which was significantly higher than that after primary operation (6.7%) (p < 0.05), and that after first reoperation (5.8%) (p < 0.05). Seven (64%) patients who underwent a second/third reoperation had poor preoperative left ventricular function (%FS < 25%), and 5 (71%) of these required postoperative mechanical supports, and 3 (60%) of the 5 patients died of low output syndrome. We have found that poor preoperative left ventricular function and the duration on cardiopulmonary bypass, but not the number of reoperation were correlated with operative mortality. Continued efforts should be directed to decrease the mortality for multiple reoperative valve surgery.     

Influence of preoperative left ventricular function on results of homograft replacement of the aortic valve for aortic regurgitation

The effect of preoperative left ventricular function on eraly and late prognosis was assessed in 69 patients with aortic regurgitation who underwent homograft replacement of the aortic valve. Patients were divided into two groups: Group A (38 patients) had an ejection fraction of 0.46 or more and Group B (31 patients) had an ejection fraction of 0.45 or less. Clinical data, hemodynamic data, and operative results were compared in the two groups. In Group A there was one early death (2.6%) and there were two late deaths (5.3%) compared to two early deaths (6.5%) and seven late deaths (22.6%) in Group B during a follow-up period of 13 to 98 months (mean, 49 months). Actuarial analysis showed a 94% survival at 6 years in Group A compared to 80% in Group B. Twenty-four patients were reinvestigated by repeat cardiac catheterization and coronary angiography at a mean time of 38 months following valve replacement. Left ventricular function was assessed by computerized quantitative radial analysis of segmental wall motion. Improvement in left ventricular function occurred in eight of the 14 patients reinvestigated in Group B, and appeared to be closely related to the etiology of the initial valve lesion. Despite the higher mortality rate in patients with poor left ventricular function, most derived considerable benefit from operation.     

Operative flow measurements and coronary bypass graft patency.

Early (one week) and late (one year) postoperative angiography was performed in 142 patients having 310 grafts (117 right coronary artery [RCA], 134 left anterior descending [LAD], and 59 circumflex coronary artery [CCA]) to assess the factors responsible for failure of aorta-coronary artery saphenous vein grafts. Early catheterization revealed an 85.5 per cent patency rate with similar rates for each artery (RCA 88 per cent, LAD 85 per cent, and CCA 81 per cent). At one year 238 grafts remained patent, for a cumulative patency rate of 76.8 per cent with a similar distribution for each vessel (RCA 75 per cent, LAD 78 per cent, and CCA 76 per cent). Intraoperative flow measurements were correlated with early and late patency. Grafts with a basal flow less than 20 ml. per minute have a 42 per cent early closure rate and a 21 per cent late closure rate (cumulative 63 per cent). A basal flow of less than 40 ml. per minute was associated with a 25 per cent early failure and an 11 per cent late failure rate (cumulative 36 per cent). Basal flow at levels greater than 40 ml. per minute was not associated with an increased probability of graft closure. Absence of reactive hyperemia (30 second graft occlusion) was associated with a 19 per cent probability of early closure and a 31 per cent probability of cumulative thrombosis. A papaverine-induced flow increase (15 mg. given into the graft) of less than 100 per cent over basal flow gave a 20 per cent probability of early failure and 30 per cent probability of cumulative closure. Thus intraoperative basal flow measurements are of predictive value in determining the fate of aorta-coronary artery vein bypass grafts, and vasodilatory maneuvers provide little additional information.     

Tension on coronary bypass conduits. A neglected cause of real or potential obstruction of saphenous vein grafts.

Of 41 saphenous vein aorta-coronary bypass grafts from 21 patients, abnormal graft tension was judged to be present at necropsy in 6 grafts (15 per cent) from 5 patients (24 per cent). Five (33 per cent) of 15 grafts placed to the right coronary system and one (3 per cent) of 26 grafts to the left coronary system were under excess tension. The abnormal tension appeared to result from the insertion of grafts too short to accommodate normal or abnormal distention of the right atrium and ventricle (graft to distal right coronary or posterior descending coronary artery) or of the pulmonary trunk (graft to left coronary system) after discontinuation of cardiopulmonary bypass or development of acute congestive cardiac failure.     

Use of the internal mammary artery as a free graft with reimplantation of the proximal end onto the ascending aorta. Apropos of 39 cases]

From January 1987 to January 1991, 104 patients received bilateral internal mammary artery grafts and 39 of them had coronary bypass with a free graft implanted on the ascending aorta. There were 35 men, with a mean age of 57.35 years (range 41 to 70 years). 87% of them had stable angina, and 23 had preoperative myocardial infarction. The left ventricular function was good in 77 per cent of cases. 23 patients had three vessel disease (61.5%), 13 two vessel diseases (30.7%), 2 one vessel disease (5.12%) and one a left main coronary stenosis. Left internal mammary artery was used in two patients on the left descending artery and the right internal mammary artery was used in 37 patients: 15 on the circumflex, 15 on the right coronary, 4 on the LDA and 3 on the diagonal artery. Five patients had one graft, 32 two grafts and one three grafts (bilateral mammary and saphenous vein). Hospital mortality was 2.56% (1 patient) and there were 2 late deaths (5.12%). There were 5 perioperative myocardial infractions (12.8%) and no sternal infections. The mean follow up is 21 months (range 3 to 46 months). At follow-up, 34 patients (87.2%) were asymptomatic, and there were no myocardial infarctions. Postoperative angiography in 8 patients (mean postoperative time 2.5 months) showed that all the grafts were patent. This analysis demonstrates that free IMA graft has a low operative risk and provides excellent long term functional improvement and survival.     

Surgical treatment of the left main trunk and left main equivalent coronary artery disease

The comparative studies on operative and hemodynamic results following aorto-coronary bypass grafting were performed in 9 patients with left main trunk (LMT) stenosis and 20 with left main equivalent (LME). One of 20 LME had bypass grafts occluded on the postoperative angiogram. There were two operative deaths, one in LMT, another in LME, and one late death. Following results were obtained in 8 LMT (Group I) and 15 LME (Group II) whose all bypass grafts were patent. There were significantly higher operative mortality rate and the incidence of perioperative myocardial infarction in Group I (11.1% versus 5.0%). Cardiac index and left ventricular ejection fraction significantly increased postoperatively in both groups. Mean Vcf and PLVSP/LVESV significantly increased postoperatively in Group II, but not in Group I. Left ventricular anterior segmental wall motion significantly increased in both groups and apical in Group I, whereas it did not in the postero-inferior segment. The completely revascularized patients had a better postoperative left ventricular function comparing with the incompletely revascularized patients. Angina disappeared postoperatively in all patients in Group I and 12 (75%) in Group II. In both groups, NYHA classification was improved from class III or IV preoperatively to class I or II postoperatively. Postoperative 8 years actuarial survival rate was 88.2% in Group I and 84.6% in Group II. In conclusion, it was suggested that much more strict perioperative management and complete revascularization were needed in the patient with LMT.     

Initial experience with beating heart surgery: comparison with fast-track methods.

Cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) may increase postoperative complications in high-risk patients. The goal of this study is to retrospectively review a series of consecutive patients undergoing conventional CABG using a fast-track recovery method and to compare this series with the initial series of patients undergoing beating heart surgery using either the single-vessel minimally invasive approach or the off-pump multivessel bypass technique with a median sternotomy. One hundred fifty-eight consecutive patients underwent CABG. One hundred four patients underwent conventional CABG using CPB with a short-pump fast-track recovery method (Group A). Twenty-nine patients underwent a single-vessel bypass via a left anterior thoracotomy off pump [Group B, minimally invasive direct coronary artery bypass (MIDCAB)]. Twenty-five patients underwent multivessel CABG with a median sternotomy off pump (Group C). Short-pump fast-track (Group A) patients exhibited minimal complications and expedient recovery and received extensive revascularization. Off-pump multivessel patients (Group C) received fewer bypass grafts, had more preoperative comorbidity, and recovered as quickly as lower-risk fast-track short-pump patients (Group A). Single-vessel off-pump patients (Group B, MIDCAB) were younger elective patients and demonstrated no recovery advantage. The overall mortality was 1.8 per cent. The conversion rates from beating heart surgery to CPB for groups B and C were 10.3 and 16 per cent, respectively. The postoperative hospital length of stay for groups A, B, and C were 4.8+/-2.4, 3.9+/-1.8, and 5.2+/-2.3 days, respectively. Eliminating CPB is not as important as reducing exposure for minimizing operative risk. Beating heart surgery is an adjunct to conventional CABG with CPB. The off-pump multivessel bypass technique is best suited for high-risk patients requiring three grafts or fewer, whereas MIDCAB is best suited for single-vessel bypass that cannot be managed using interventional percutaneous techniques; however, the recovery advantage with MIDCAB is not apparent. Patients requiring more than three bypass grafts should undergo conventional CABG with CPB.     

Significance of changes in resting left ventricular ejection fraction after coronary artery bypass grafting

The prognostic significance of changes in resting left ventricular ejection fraction was examined in 102 patients who underwent successful coronary artery bypass grafting. Between preoperative and early postoperative radionuclide ventriculography, mean resting left ventricular ejection fraction improved from 47.2% to 53.9% (p less than 0.01). Left ventricular ejection fraction increased by 5% or greater in 64 patients (63%), remained unchanged (within 4%) in 31 (30%), and decreased by at least 5% in 7 (7%). During 14 to 39 months (mean 27 months) of clinical follow-up, patients with normal preoperative left ventricular ejection fraction had a lower prevalence of recurrent angina, congestive heart failure, and mortality resulting from cardiovascular disease. Cardiovascular morbidity and mortality occurred with equal frequency for patients who did and did not show early postoperative improvement in left ventricular ejection fraction (36% versus 39%). Among 69 patients who had a third radionuclide ventriculography at late follow-up, left ventricular ejection fraction was less than the early postoperative value in 69% and less than the preoperative result in 36%. Patients with early postoperative improvement in left ventricular ejection fraction were more likely to retain resting left ventricular contractile function, at least at the preoperative level (71% versus 46%).