Emergency myocardial revascularization

Medical and surgical management of early Q wave myocardial infarction. I. Effects of surgical reperfusion on survival, recurrent myocardial infarction, sudden death and functional class at 10 or more years of follow-up

To define the outcome of patients given medical or surgical therapy for Q wave myocardial infarction, 387 patients were followed up for 10 to 13 years (mean 11.4). On study entry the groups had similar distributions for variables such as mean age, gender, previous myocardial infarction, abnormal creatine kinase activity, area of infarction, number of vessels diseased and clinical classification. The hospital mortality rate of the medical versus surgical group was 11.5% (23 of 200) versus 5.8% (11 of 187) (p = 0.07). Early reperfusion (that is, less than or equal to 6 h) resulted in a lower mortality rate than did medical therapy--2% (2 of 100) versus 11.5% (23 of 200) (p less than 0.05)--whereas the hospital mortality rate with late reperfusion was 10.3% (9 of 87). The long-term mortality rate of the medical and surgical groups was 41% (82 of 200) versus 27% (51 of 187) (p = 0.0007) with use of an adjusted Cox proportional hazards model. In the survivors, the differences between medical and surgical groups in recurrent myocardial infarction, mortality associated with reinfarction and sudden death were prospectively followed and evaluated by the life table method. Recurrent myocardial infarction was not prevented by surgical reperfusion or medical therapy (23% in both groups), however, the mortality rate in patients with recurrent infarction was higher in the medical therapy group--36.6% (15 of 41) versus 17.5% (7 of 40) (p = 0.04). The mortality difference did not depend on early or late surgical reperfusion. In the in-hospital survivors, the incidence of sudden death was 17.5% in the medical (31 of 177) versus 7.4% (13 of 176) in the surgical group (p = 0.01). This difference was much more pronounced in the early reperfusion group. Functional class was significantly lower than that for medical therapy in the early reperfusion but not the late reperfusion group. Thus, in comparable groups given medical and surgical therapy for acute myocardial infarction and followed up for greater than or equal to 10 years, surgical reperfusion appears to offer improved longevity in selected cases (when implemented early) but does not prevent recurrent myocardial infarction. The associated mortality with recurrent myocardial infarction is less as is the incidence of sudden death. Finally, lower functional class occurs most often in patients given early reperfusion.

Intravenous versus intracoronary streptokinase in acute myocardial infarction

Nine studies specifically dealing with the comparison of intravenous streptokinase (IVSK) and intracoronary streptokinase (ICSK) in the treatment of acute myocardial infarction (MI) were analyzed to determine if IVSK is as efficacious as ICSK in achieving thrombolysis. Pooled data from the studies yielded success rates of 73% for IVSK and 72% for ICSK. Considering that the studies which did not perform preintervention angiogram may have overestimated the thrombolytic success rate in IVSK patients, there is a possibility that ICSK may be slightly more effective in achieving acute reperfusion. Bleeding complications were similar, and a systemic lytic state was observed in both treatment groups. No definitive conclusions can be drawn regarding the differences between groups in improvements of left ventricular function and mortality rates. ICSK has the advantage of direct documentation of reperfusion and spares the patient the risk of anticoagulation should the attempt fail. On the other hand, IVSK is cheaper, easier to administer, and can logistically be given earlier (even in the emergency room or ambulance) than ICSK; it is therefore more widely available, and may be the preferred mode of treatment in community hospitals where cardiac catheterization facilities are not readily available, if streptokinase is to be given at all.

Acute myocardial infarction treated with intracoronary streptokinase: a report of the Society for Cardiac Angiography

The Society for Cardiac Angiography maintains a registry of intracoronary streptokinase therapy (IC-SK) in patients with acute myocardial infarction. Between July 1981 and August 1984, 1,029 patients were entered into the registry. The baseline and clinical characteristics of patients were determined, the early results of therapy were evaluated, and baseline characteristics of those in whom reperfusion was achieved were compared with those in whom it was not. Multivariate discriminant analysis was used to identify the predictors of reperfusion and hospital mortality. The overall rate of reperfusion was 71.2%. Reperfusion was positively associated with hypotension, absence of cardiogenic shock and early treatment. The hospital mortality rate for all patients was 8.2% and was higher for women and the elderly. The hospital mortality was significantly lower among patients in whom reperfusion was achieved compared with those in whom it was not (5.5% vs 14.7%, p less than 0.0001) and for several high-risk subgroups. Thus, coronary artery reperfusion induced by IC-SK significantly reduces hospital mortality in high-risk patients with acute myocardial infarction. High-risk patients in whom reperfusion fails with IC-SK therapy should be considered for early coronary angioplasty or coronary artery bypass surgery.

Anterior transmural myocardial infarction: effects of surgical coronary reperfusion on global and regional left ventricular function

Global and regional left ventricular function were assessed before and after surgical coronary reperfusion in 54 patients surviving anterior transmural myocardial infarction. Two groups were identified. Group I (n = 34) was treated within 4.8 +/- 0.7 (mean +/- standard deviation) hours of onset of symptoms of anterior transmural myocardial infarction, and Group II (n = 20) was treated 9.2 +/- 4.8 hours from the onset of symptoms (p less than 0.01). On study entry, the two groups were similar in all characteristics except global left ventricular ejection fraction (48 +/- 9 versus 42 +/- 13%, p less than 0.05). Regional ejection fraction was obtained by computer-assisted planimetry from ventriculographic tracings at end-systole and end-diastole. The anterior wall was divided into four equal segments from the apex (area 1) to base (area 4). Areas 2 and 3 defined the midportion of the anterior wall of the left ventricle. This yielded four fractional changes expressed as ejection fraction in percent. Global and regional ejection fractions (from apex to base) of the anterior wall significantly improved in Group I (from 48 +/- 9 to 55 +/- 11%; 7 +/- 17 to 18 +/- 20%; 12 +/- 14 to 25 +/- 18%; 25 +/- 15 to 38 +/- 17%; and 39 +/- 13 to 41 +/- 12%) (p less than 0.05, except for the basal area), but only to a minor degree in Group II (from 42 +/- 13 to 45 +/- 16%; 9 +/- 10 to 13 +/- 15%; 10 +/- 10 to 17 +/- 10%; 27 +/- 16 to 32 +/- 14%; and 37 +/- 10 to 36 +/- 13%) (all p values were not significant [NS] except for region 2). These data suggest significant enhancement of global function and regional wall motion in selected patients if surgical reperfusion is performed within 6 hours from the onset of symptoms of anterior infarction. Little improvement can be expected when the procedure is instituted later than 6 hours from peak symptoms, although improvement in some patients occurs if adequate collateral perfusion or nontotal left anterior descending coronary occlusion is present. In spite of functional improvements, some contractile deficit persisted throughout the period studied even when successful reperfusion was achieved early during evolving anterior transmural myocardial infarction.

Coronary bypass for relief of persistent pain following acute myocardial infarction

Between January, 1976, and April, 1980, 116 patients had urgent myocardial revascularization for clinical instability within 30 days of acute myocardial infarction (MI). Group 1 (8 patients) had coronary bypass grafting within 24 hours of acute MI; Group 2 (20 patients) had coronary bypass grafting 2 to 7 days after acute MI; and Group 3 (88 patients) had coronary bypass grafting 8 to 30 days after infarction. Indications for operation were persistent or recurrent pain (81%), pain plus ventricular arrhythmias (12%), and pain plus compelling anatomy. The incidence of single-vessel, triple-vessel, and left main coronary artery disease was 28%, 31%, and 12%, respectively. There were no hospital deaths in the series. The incidence of inotropic requirements, postoperative intraaortic balloon pumping, ventricular arrhythmias, and perioperative infarction was higher in patients operated on within 7 days of acute MI than for patients having coronary bypass grafting after this time. There have been 5 late deaths during a mean follow-up of 14 months. Actuarial survival was 97% at 18 months. Seventy-one percent of patients are presently pain free. Graft patency was 84% in 17 patients recatheterized after coronary bypass grafting and in 14 patients, grafts placed into the area of infarction were patent. This study suggests that the frequency of perioperative complications will be increased in patients operated on within one week of MI, but after this period, coronary bypass grafting can be accomplished with the same morbidity as the of elective operation.

Unstable angina pectoris: a randomized study of patients treated medically and surgically

Fifty patients with the clinical syndrome of unstable angina pectoris were evaluated. Twenty-seven were randomized into medical or surgical treatment groups and subsequently followed up. The results of the study reveal that: (1) there is approximately a 16 percent incidence rate of significant left main coronary artery disease in patients with this entity at our institution; (2) 10 percent of patients do not have angiographically significant coronary artery disease; (3) pain relief is better in the surgically treated patients, but the 1 1/2 year survival rate is not significantly different between the groups; (4) 50 percent of the medically treated patients again had the syndrome of unstable angina pectoris in the initial few months of the follow-up period; (5) the operative and late postoperative mortality rate in patients presenting with unstable angina pectoris and left main coronary artery disease in this small group of patients was 43 percent; and (6) four of six patients with this syndrome whose condition was deemed inoperable and who were not randomized died within the subsequent few months.

Treatment of cardiogenic shock in myocardial infarction by intraaortic balloon counterpulsation surgery

Thirty-seven patients in cardiogenic shock due to acute myocardial infarction were treated with intraaortic balloon counterpulsation and/or surgery. Eighteen of these patients were treated with counterpulsation alone; eight survived and five were in functional class I or II at the time of follow-up; two were in functional class III, and one was in functional class IV. Nineteen patients were treated surgically, eight survived and seven were in functional class I or II at the time of follow-up; one was in functional class III. Good functional recovery with counterpulsation alone is most common with inferior infarction. With surgery, functional recovery depends not only on the extent of the infarction and the coronary anatomy, but also on the ability to perform surgery within 12 hours of infarction or to support the patient with mechanical means for 10 to 14 days after the infarction and then perform surgery.

Acute coronary insufficiency. Review of 46 patients

Forty-six patients admitted with acute coronary insufficiency are reviewed. All were investigated by coronary angiography; 4 had normal coronary arteries and are included in this study; the remainder had a distribution of coronary artery disease similar to other angina patients. The clinical and angiographic findings, management, and subsequent course of the other 42 patients are presented. Fourteen patients (33%) in whom rest pain persisted after 48 hours underwent emergency coronary angiography, with 3 deaths; of the surviving 11 who had acute saphenous vein bypass grafting, 2 died at operation and 3 had perioperative myocardial infarctions. Seventeen patients (41%) who initially improved required surgery within 6 months because of symptoms. Eleven patients (26%) were not operated on. It is concluded that acute coronary insufficiency is best managed initially by intensive medical therapy but a high proportion will require surgery later because of disabling angina. Early investigation and surgery are associated with a high mortality and incidence of myocardial infarction. Survivors of surgery are symptomatically improved and there is a low incidence of late infarction and death.

Emergency myocardial revascularization

From 1969 to 1975, 175 patients with acute coronary insufficiency underwent emergency saphenous vein aorto-coronary bypass grafting (SVBG). The patients were divided into two groups: group I, unstable angina (165 patients) and group II, acute evolving myocardial infarction (ten patients). In group I, the hospital mortality was 8-4%, the incidence of post-operative myocardial infarction was 10-3%. Long-term follow-up was obtained for an average of 25 months, functional improvement was definite in the majority of the patients and actuarial survival curves show 87% patients alive at the end of 48 months. In group II, the hospital mortality was 30%; seven of ten patients had good results.

Natural history of unstable angina with medical or surgical therapy

In order to establish the natural evolution of unstable angina under medical treatment and to determine the possible benefits of revascularization surgery, 113 patients were studied; 51 received medical treatment (24 with intermediate syndrome and 27 with progressive angina), and 62 others received surgical treatment (28 with intermediate syndrome and 34 with progressive angina). After a mean follow-up of 32 months, the mortality in the medically treated groups was 46 percent (11/24) with intermediate syndrome and 7 percent (2/27) with progressive angina (P less than 0.005), and the incidence of myocardial infarction was 38 percent (9/24) and 7 percent (2/27), respectively (P less than 0.01). Moreover, in comparing cases treated medically or surgically, the mortality was as follows: intermediate syndrome treated medically, 46 percent (11/24) vs 11 percent (3/28) in those treated surgically (P less than 0.005); and progressive angina treated medically, 7 percent (2/27) vs 9 percent (3/34) in those treated surgically (P = 0.85). The incidence of myocardial infarction was as follows: intermediate syndrome treated medically, 38 percent (9/24) vs 14 percent (4/28) in those treated surgically (P less than or equal to 0.056); and progressive angina treated medically, 7 percent (2/27) vs 12 percent (4/34) in those treated surgically (P greater than 0.55).

Unstable angina pectoris

Unstable angina is a syndrome which comprises a spectrum of symptomatic manifestations of coronary artery disease which lies between stable angina pectoris and acute myocardial infarction. Patients fall into three groups: angina of recent onset (4 weeks), angina of changing pattern, and angina occurring at rest (longer than 15 minutes). The syndrome may presage acute myocardial infarction or sudden death, or may itself be the manifestation of a myocardial infarction. The pathophysiology may involve primary cardiac events or extracardiac precipitating factors, and does not appear to be the consequence of a particular anatomic pattern of coronary artery disease. Pain may occur as a result of regional reduction of coronary flow to pressure-dependent areas of myocardium during states of increased myocardial oxygen demand. Persisting ischemia leads to infarction via a series of events which may include myocardial edema formation, increased beta-sympathetic tone, and others which have been experimentally modified by interventions designed to limit infarct size. Although the incidence of acute myocardial infarction and death was high in early studies, in recent reports acute infarction occurs in under 15.5 per cent and death in under 2 per cent. Patients at high risk are those pain persists with bed rest, and those with preceding stable angina pectoris or myocardial infarction. Prognostic differences among Groups 1, 2, and 3 may exist but cannot be assessed from available studies. Studies of the management of unstable angina have generally been uncontrolled. Hospitalization, bed rest, and short- and long-acting nitrates are generally employed in Groups 2 and 3 patients and the marked reduction in myocardial infarction rates from early to recent studies tends to support these approaches. Anticoagulants are less used now than formerly. Propranolol can produce a significant reduction of myocardial oxygen consumption and may redirect coronary flow to ischemic areas. The drug has effectively controlled pain in several studies and is now widely used to manage unstable angina. Aortocoronary bypass surgery has been extensively employed but there is only one preliminary report of a controlled study available. The role of surgery is not yet defined. The optimal approach to therapy may eventually involve the use of medical therapy, including beta-blockade to stabilize patients, with delayed semielective coronary angiography and surgery in those who respond. Emergency angiography and surgery might then be reserved for the high-risk group of patients whose pain persists during optimal medical therapy.

Acute coronary embolism complicating bacterial endocarditis: operative treatment

A patient with bacterial endocarditis and no previous history of angina substained an acute anterolateral myocardial infarction while awaiting surgery. Selective coronary arteriography revealed a filling defect in the left anterior descending coronary artery with limited flow beyond the area of occlusion. A calcific embolus from the infected aortic valve was removed at the time of valve replacement, and the patient had an uneventful immediate postoperative course. Late postoperatively paravalvular aortic regurgitation recurred before and after a second repair.

Ventriculography and coronary arteriography in the acutely III patient. Complications, extent of coronary arterial disease, and abnormalities of left ventricular function

Of 99 patients who underwent "emergency" diagnostic studies, 82 had "unstable angina" (group A), 15 had recent myocardial infarction (group B), and two had intractable congestive heart failure due to acute mitral regurgitation (group C). Two cardiac and two local complications occurred either during the procedure or during the following 48 hours. There were no deaths or myocardial infarctions. Ten (12 percent) patients of group A had "normal" coronary arteries and normal left ventricular function; 13, 26 and 33 patients had one, two, and three coronary arteries involved, respectively. Those with three-vessel disease had a significantly higher left ventricular end-diastolic pressure (LVEDP) and lower ejection fraction (EF) than those with one- and two-vessel disease. Those with previous myocardial infarction had a significantly higher incidence of reduced EF and of wall motion abnormalities than those without a previous myocardial infarction. All patients in group B had significant coronary arterial disease, and 80 percent (12) had abnormal left ventricular function. Their mean LVEDP and EF were significantly higher and lower, respectively, than those found in group A. In conclusion, acutely ill patients were studied with low risk. Most patients had three- or two-vessel disease. Abnormal left ventricular function was related to three-vessel disease and to recent and old myocardial infarction.

Prognosis of new and worsening angina pectoris

The natural history of new and worsening angina pectoris was studied in 251 men aged under 70 years. Most were ambulant and all were referred by selected general practitioners to a special hospital clinic over two and a half years. Heart attacks developed in 39 patients, nine of whom died. Seventy-two per cent of the attacks occurred within six weeks of the onset or worsening of angina. Of the 212 patients who did not suffer myocardial infarction and who were clinically reviewed six months after their first attendance 66 had been pain free for the previous three months and 14 had experienced only infrequent attacks of angina. Of the 128 men aged under 65 years who were previously in employment 81% had returned to full-time work six months after their first attendance. A discriminant function analysis using many variables was made to develop a predictive index that would allow patients with new or worsening angina who were likely to develop serious cardiac complications to be identified. This did not prove possible, and the only predictive factor of significance was an increased cardiothoracic ratio. The syndrome of new and worsening angina has a low risk of early death, and many patients are symptom free six months later. In general, emergency coronary arteriography and surgery is not indicated.

Early and late results after surgical treatment of preinfarction angina

Among 3,707 patients who underwent aortocoronary bypass, 302 had preinfarction angina. Coronary angiography revealed single-vessel disease in 43 patients, double-vessel disease in 81, and triple in 178 patients. Plane ventriculography showed contractility to be normal in 178 patients, fair in 88, and poor in 36 patients. Left ventricular end-diastolic pressure was normal in 203 patients, 13 to 23 mm Hg in 73, and larger than or equal to 24 mm Hg in 26 patients. Using cardiopulmonary bypass and moderate hypothermia, single coronary bypass was performed in 45 patients, double bypass in 120 patients, triple in 118 patients, quadruple in 15, and quintuple in 4 patients. Right coronary artery endarterectomy was necessary in 22 patients. The early mortality was 6.6% (20 patients) and was strongly related to poor contractility and congestive heart failure. One- to four-year follow-up data were obtained in 126 patients. Late myocardial infarction occurred in 11 patients and caused 4 late deaths; 3 unrelated deaths occurred. Ten patients experienced no benefit from their operations, 56 are completely asymptomatic, and 53 are significantly improved. Our results show that surgical intervention can improve the poor prognosis of preinfarction angina and appears to be superior to medical treatment.

Medical versus surgical therapy for acute coronary insufficiency. A randomized study

Forty patients with acute coronary insufficiency, including continued angina at rest and reversible ischemic electrocardiographic changes after hospitalization ("high-risk" subgroup), were randomly allotted to medical therapy or urgent surgical coronary bypass groups. In four months there were no deaths and two myocardial infarctions in 19 medical patients and one death and three myocardial infarctions in 21 surgical patients. Left ventricular ejection fraction did not change significantly in either group. The surgical patients had significantly higher functional capacities at four months as judged by lower symptomatic functional class (P less than 0.01), higher exercise angina threshold (P less than 0.001), higher pacing angina threshold (P less than 0.0001), and higher myocardial lactate extraction during pacing (P less than 0.0001). Initial medical management of patients with acute coronary insufficiency followed by elective coronary bypass in patients with continued disabling angina pectoris is a reasonable alternative to emergency bypass.

Coronary occlusion during coronary angiography

Between January 1, 1970, and December 31, 1974, 2981 patients underwent coronary arteriography. Twelve acute coronary dissections or embolizations occurred, an incidence of 0.4%. The incidences of acute occlusions for the Sones and Judkins techniques were 0.19% (4/2077 studies) and 0.88% (8/940), respectively. No instance of acute occlusion has occurred during the past 490 studies performed by the Judkins technique. Eight patients with right coronary artery dissections or circumflex emboli were treated medically. All survived, but in seven a myocardial infarction evolved. Four patients underwent emergency saphenous venous bypass grafting because of refractory ventricular fibrillation (two patients) or because large amounts of myocardium were thought jeopardized (two patients). All patients in this group had interruption of flow supplying the left anterior descending coronary artery. Despite surgical intervention in less than three hours in all patients, survivors all sustained transmural myocardial infarctions. Three patients survived surgery and were discharged home.

Nutrient myocardial blood flow in experimental myocardial ischemia. Effects of intraaortic balloon counterpulsation and coronary reperfusion

This experimental study was designed to evaluate the effect of intraaortic balloon pumping (IABP) upon nutrient myocardial blood flow (NMBF) following acute myocardial ischemia in dogs, but also to determine whether IABP improves NMBF following revascularization. Localized myocardial ischemia was produced by ligation of one or two small branches of the circumflex coronary artery combined with a three hour snare occlusion of the left anterior descending coronary artery distal to the first septal branch. NMBF was measured by NaI131 washout at three points corresponding to the peripheral, intermediate, and central zones of the infarct. Occlusion of the coronary arteries reduced NMBF. Release of occlusion after three hours, or the equivalent of coronary artery revascularization, increased NMBF but did not restore it to control levels. The increase in flow was more marked in the peripheral zones of ischemia. IABP increased NMBF significantly both during and after release of occlusion. The effect was sustained after cessation of IABP only when the latter was maintained during the period of reperfusion. The results indicate that NMBF, defined by washout of a locally injected tracer, was improved by both IABP and reperfusion. The beneficial effect was maximal when the two techniques were combined.

Myocardial revascularization after acute infarction

The purpose of this study was (1) to establish the maximal interval between the onset of ischemia and reperfusion that would permit a decrease in the size of infarction, and (2) to evaluate the relation between changes in infarct size and preservation of cardiac function. Studies were carried out in 19 dogs of which 13 had temporary (1 to 3 hours) occlusion of the left anterior descending coronary artery. The hospital course of 15 patients of whom 13 underwent myocardial revascularization within 8 hours of acute infarction was also reviewed. In dogs, the eventual pathologic infarct size was significantly reduced if reperfusion was performed within 2 hours of ischemia. After 2 hours of ischemia, the revascularized segment remained dyskinetic on angiographic assessment and cardiac function was depressed. After 3 hours of ischemia, in spite of a patent coronary artery, the extent of infarct and dykinesia was greater than during ligation of the left anterior descending coronary artery. In patients, small infarcts developed with revascularization performed more than 4 hours after infarction but with revascularization of the left anterior descending coronary artery the size of the dyskinetic area (as assessed with angiography) was similar to that in patients with a closed graft to the left anterior descending coronary artery but with a patent graft to its diagonal branch. In all patients after revascularization the extent of the left ventricular dyskinetic area was smaller and cardiac function was significantly better than in patient who did not receive revascularization for complete occlusion of the left anterior descending coronary artery. In spite of successful revascularization, electrocardiographic evidence of transmural infarction persisted postoperatively. It is concluded that reperfusion of an area of myocardium that has been ischemic for less than 2 hours in dogs or less than 4 hours in man may lead to a significant reduction in the extent of infarction as well as improvement in cardiac function. However, the revascularized area remains angiographically dyskinetic and electrocardiographically abnormal.

Coronary revascularization in "high" versus "low-risk" patients: The role of myocardial protection

Postoperative mortality, infarction, and need for inotropic support are reportedly increased following myocardial revascularization in "high-risk" patients. We believe these complications result from inadequate protection of the compromised myocardium and should not occur with greater frequency in "high-risk" than "Low-risk" patients if the heart is optimally protected during the entire course of the operative procedure. Results following revascularization in 50 consecutive "low-risk" and 50 consecutive "high-risk" patients were analyzed. One or more of the followin factors were present in the "high-risk" group: ventricular dysfunction--ejection fraction less than 0.4, preinfarction angina, evolving infarction, recent infarction (less than 2 weeks), and refractory ventricular tachyarrhythmia. The following principles were used in all patients to minimize ischemic injury: 1) avoidance of pre-bypass hypo- or hypertension, 2) limitation of ischemic arrest to less than 12 minutes, 3) avoidance of ventricular fibrillation, and 4) prolongation of total bypass as necessary to repay the myocardial oxygen debt. Postoperative inotropic support was required in 10% of "high" and 10% of "low-risk" patients, new postoperative infarction developed in 10% of "high" vs. 10% "low-risk" patients; death occurred in 2% of "high" vs. 4% "low-risk" patients. These results are comparable and indicate that optimum myocardial protection allows safe revascularization in the "high-risk" patient.

Aortocoronary vein bypass in patients with angina pectoris

In the 3-year period from May 1971 to April 1974, 90 patients had aortocoronary bypass for angina pectoris at Ulleval Hospital. One patient died shortly after the operation (operative mortality 1.1%). There were no further deaths in the observation period. Clinical improvement was seen in 93% of the patients, early shunt patency in 92%. The study suggests that patients with isolated affection of the right coronary artery should not have bypass, because these patients 1) had less severe symptoms, 2) had better preserved left ventricular function, and 3) seemed to have a smaller chance of benefiting from the operation than the other patients. Multiple shunts gave good clinical results and carried no higher surgical risk than did single shunts. Good clinical results were seen also in patients with occluded shunts provided they had at least one patent shunt too. Graft occlusion occurred early and was associated with low graft flow as measured intraoperatively. Graft occlusion was not usually followed by demonstrable myocardial necrosis. In view of the small operative risk and the high score of symptom relief it is concluded that all patients with angina pectoris that does not readily respond to medical treatment, should be considered for aortocoronary bypass.

Late results following emergency saphenous vein bypass grafting for unstable angina

Fifty-five consecutive patients with intermittent resting chest pain persisting more than 24 hours after hospitalization and accompanied by ECG changes representative of ischemia were operated urgently more than one year ago. Recent cases with shorter follow-up are excluded. Twenty-eight patients had single grafts, 23 had double grafts, three had triple grafts, and one a quadruple graft. There were three operative deaths (5%) and one sudden late death (2%). There were six early Mls and three late Mls. Follow-up ranges from 12 to 52 months (mean 24 months) with nine patients followed for four years. Actuarial analysis indicates a projected survival rate of 93% three years postoperative. Twenty-three survivors are Functional Class (FC) I, 19 are FC II, and eight are FC III. Functional class could not be determined in one survivor. Thirty patients had postoperative angiography one week to 32 months postop. 35/51 grafts were patent. Only three patients had no patent grafts. There were no significant differences between mean preoperative and postoperative left ventricular end-diastolic pressures (assessed in 20 patients) or ejection fractions (assessed in ten patients). The extremely low mortality early and late postop (7%), the low incidence of Ml (16%), and the excellent functional results after extended follow-up indicate that emergency saphenous vein bypass grafting is an effective therapy for unstable angina.