Percutaneous transluminal coronary angioplasty in patients with prior coronary bypass surgery.

To improve symptomatic status and avoid reoperation, 122 initial and 7 repeat percutaneous transluminal coronary angioplasty procedures were performed in 116 patients with disabling angina pectoris at a mean of 26.8 months (range 2 to 132) after coronary bypass surgery. Marked angiographic improvement (greater than 30% reduction in diameter stenosis) was obtained in 107 (88%) of the 122 initial procedures and in all 7 repetitions. Mean stenosis was reduced from 78 +/- 13% (mean +/- standard deviation) to 25 +/- 13% (p less than 0.0001) and mean pressure gradient from 49 +/- 15 to 11 +/- 8 mm Hg (p less than 0.0001). Complications were: emergency surgery (three patients), Q wave infarction (one patient), myocardial infarction by enzyme criteria only (four patients) and non-occluding coronary dissection (one patient). There were no neurologic or peripheral vascular complications and no early deaths. One late death occurred 14 months after an unsuccessful but uncomplicated angioplasty procedure. At a mean follow-up of 8.3 months, 88 patients (76%) were free of angina or in improved condition. In patients followed up for at least 6 months, evidence of restenosis occurred in 9 (53%) of 17 saphenous veins, 1 (50%) of 2 proximal graft anastomoses, 4 (18%) of 22 distal graft anastomoses and 5 (14%) of 37 native coronary arteries. When coronary anatomy is suitable, percutaneous transluminal angioplasty is an attractive alternative to reoperation in symptomatic patients with prior coronary bypass surgery.

Importance of complete revascularization in performance of the coronary bypass operation.

Cardiac Data Bank records of 1,238 patients with triple-vessel disease (greater than or equal to 50% diameter reduction) who had undergone coronary bypass surgery were reviewed and divided into 2 groups depending on whether complete (n = 773) or incomplete (n = 465) revascularization had been accomplished. Patients with complete revascularization had a higher incidence of a normal preoperative electrocardiogram than did patients with incomplete revascularization (23 versus 14%, respectively, p less than 0.0001). The ejection fraction for both completely and incompletely revascularized patients was good (m = 0.60 and 0.57, respectively). The mean number of grafts per patient for the 2 groups was 3.8 and 2.6 (p less than 0.0001). There was no significant difference between the 2 groups with regard to postoperative inotropic requirements (8 and 7%), ventricular arrhythmias (1.8 and less than 1%), necessity for intraaortic balloon pumping (1.6 and 1.5%, hospital mortality (1.2 and 2.8%), or myocardial infarction (4.3 and 4.8%). Survival at 5 years was significantly greater (p less than 0.001) in patients with complete (88.5%) than in those with incomplete revascularization (83.5%). Reemployment occurred more often in patients with complete (52%) than in those with incomplete revascularization (40%) (p less than 0.001), and more patients were free of angina after complete (70%) than after incomplete revascularization (58%) (p less than 0.0005). Long-term survival appeared to be mediated primarily through improved revascularization rather than through differences in left ventricular function.

Complete atrioventricular canal associated with tetralogy of Fallot: clinical experience and operative methods.

Data on 8 children with the combined anomalies of complete atrioventricular canal and tetralogy of Fallot are presented. Six of the children had only a palliative procedure, and only 1 of these patients is doing relatively well at the present time from a clinical standpoint. Two of the remaining 5 children undergoing palliative procedures have not been helped significantly, and 3 of the children in this group subsequently died. Two children have had an attempted total correction of this complicated intracardiac problem. One of these children, in whom the diagnosis of atrioventricular canal was not made preoperatively, died in the early postoperative period. In the other child, the correct diagnosis was made preoperatively, and a satisfactory, totally corrective procedure was achieved. The patient is asymptomatic at this time.

Recognition and management of ascending aortic dissection complicating cardiac surgical operations.

This study retrospectively reviews the hospital records of 24 patients who developed ascending aortic dissection during or following 6,943 cardiac surgical procedures performed from January, 1971, through December, 1981. Group I consists of 15 patients with ascending aortic dissection presenting intraoperatively during myocardial revascularization. Group II consists of nine patients, seven who underwent myocardial revascularization and two who underwent aortic valve replacement, who developed ascending aortic dissection 30 minutes to 21 days after cardiac operation. Four of these patients had poorly controlled hypertension postoperatively. Surgical repair was attempted in all patients in Group I, with an operative mortality of 33%. The major cause of death was myocardial dysfunction secondary to ischemia. There were no operative deaths among six patients managed with closed plication techniques alone. Four of nine patients in Group II underwent ascending aortic dissection repair with an operative mortality of 50%. The overall mortality in Group II was 78%. The major factor in this high mortality was a delay in diagnosis and surgical therapy. Early diagnosis of the intraoperative or postoperative ascending aortic dissection process is essential to minimize the extent of dissection and prevent delay of definitive surgical therapy. Closed aortic plication of the intimal injury rather than more extensive aortic repair may reduce morbidity and mortality in selected patients.

Combined carotid and coronary operations: when are they necessary?

Three groups of patients were analyzed to ascertain the risk of combined carotid/coronary operations and the risk factors for perioperative stroke following coronary artery bypass (CAB). Group 1 (N = 132) had simultaneous carotid endarterectomy and CAB, Group 2 (N = 51) were patients having perioperative stroke following elective CAB, and Group 3 (N = 169) had CAB alone but had prior history of either asymptomatic cervical bruit, stroke/transient cerebral ischemic attack (TIA), or carotid endarterectomy. Hospital mortality and perioperative stroke rate in the combined carotid/coronary group were 3.0% (4/132) and 1.6% (2/126), respectively. These rates were not significantly different from those of a control group having CAB alone. Overall incidence of postoperative stroke in 5,676 patients having CAB alone was 0.9% (51 patients). The incidence of perioperative stroke in patients with asymptomatic bruit or prior history of stroke or TIA undergoing CAB alone was 3.3% (2/60) and 8.6% (6/70), respectively. The majority of strokes following CAB appear to be embolic in origin. Indications for simultaneous carotid/coronary operations are bilateral carotid disease and symptomatic carotid vascular disease associated with unstable angina, left main obstruction, or diffuse multivessel disease. Staged procedures are recommended for patients with stable angina and symptomatic carotid lesions and for difficult carotid revascularization procedures. CAB alone may be performed for most patients with asymptomatic cervical bruit, moderate or mild carotid artery obstruction, and unstable angina associated with prior stroke, although in the third situation postoperative risk of neurological injury may be increased.

Improved myocardial recovery after cardioplegic arrest with an oxygenated crystalloid solution.

Possible enhancement of myocardial protection by oxygenation of a crystalloid cardioplegic solution was evaluated in a three-part study. In Part I, canine hearts underwent ischemia followed by heterogeneous cardioplegic arrest for 45 to 60 minutes. Oxygenation led to improved recovery in the left anterior descending region (47% versus 86% recovery, p less than 0.05) (15 minutes of ischemia) and in the circumflex region (9.5% versus 52% recovery, p less than 0.05) (30 minutes of ischemia). Part II was a blind prospective randomized study in 12 patients. It examined creatine kinase, myoglobin, and lactate as well as coronary sinus flow, oxygen consumption, and cardiac work 1 hour after aortic cross-clamping during atrial and during ventricular pacing. No significant difference was demonstrable between control and oxygenated solutions. In Part III, 57 coronary bypass patients were protected with a nonoxygenated solution while 94 patients received an identical oxygenated solution. Twelve-hour creatine kinase levels were similar in the nonoxygenated (9.5 +/- 16 IU, +/- standard deviation) and oxygenated (11 +/- 22 IU) groups if the cross-clamp interval was 28 minutes or less. In patients subjected to longer than 28 minutes of arrest, the 12 hour creatine kinase MB levels were more than twice as high in the nonoxygenated group (26.5 +/- 26 IU) compared to the oxygenated group (9.9 +/- 14 IU, p less than 0.05). In this canine model of heterogeneous cardioplegia and in the routine conduct of coronary bypass operations, oxygenated crystalloid cardioplegia is superior to an identical nonoxygenated solution.

Porcine cardiac xenograft valves: analysis of survival, valve failure, and explantation.

Porcine cardiac xenografts were used for cardiac valve replacement in 1,093 patients. Hospital mortality for aortic valve replacement (AVR) was 3.7%; for mitral valve replacement (MVR), 7.8%; and for AVR + MVR, 4.7%. Total follow-up was 2,036 patient-years; maximum, 7.3 years; and mean, 1.89 years. Actuarial survival (+/- standard error of the mean) for AVR was 84% +/- 2% at 56 months; for MVR, 84% +/- 3% at 56 months; and for AVR + MVR, 86% +/- 4% at 30 months. Nonfatal thromboembolism occurred in 8 of 1,030 patients (0.78%). Anticoagulation was not routinely employed. Fifty hospital survivors (4.8%) experienced valve dysfunction; 18 of the survivors (1.7%) died; and 32 of the survivors (3.1%) underwent reoperation. The rate of dysfunction increased slowly until the sixth year when an increased rate was observed (p less than 0.0001). Patients less than 34 years old had a higher incidence of dysfunction (p less than 0.01). Thirty-two hospital survivors (3.1%) underwent explantation of the porcine valve for late dysfunction. Valve dysfunction secondary to endocarditis and paravalvular leak occurred early, while leaflet deterioration or thrombosis was more gradual in onset and was noted later. The porcine valve has functioned well for 1 to 7 years with a low incidence of valve related morbidity and mortality without routine anticoagulation in patients older than 34 years of age.

Unstable angina pectoris: comparison with the National Cooperative Study.

Seventy-eight patients having prolonged pain (greater than 20 minutes) with transient S-T segment and T-wave changes and coronary artery bypass were compared to 288 patients previously reported in the National Cooperative Study on the treatment of unstable angina pectoris. Clinical characteristics observed in the present study that differed from those of the National Cooperative Study included a more chronic anginal pattern, slightly older age, greater number of women, and higher incidence of prior myocardial infarction. The severity of vessel disease was the same for both groups. Left ventricular function was slightly better in the present series. The incidence of perioperative infarction in the present series (3.8%) was significantly less than that for surgical patients reported in the National Cooperative Study (17%). Hospital mortality was also less: 1.2% versus 2.0 and 3.0% for the medical and surgical patients, respectively, in the National Cooperative Study. Late myocardial infarction was 11% and 13% at 30 months for medical and surgical patients in the National Cooperative Study, and only 3% at 43 months in the present surgical series. Actuarial survival for the entire patient population was 95% at 42 months. The reduced hospital mortality and perioperative infarction rates were attributed to immediate operation once acute myocardial infarction has been ruled out, advances in surgical and anesthetic technique, selection of patients with preserved left ventricular function, and a trend toward complete revascularization.

Percutaneous transluminal coronary angioplasty: role of the surgeon.

Over a recent one-year period, 339 patients underwent percutaneous transluminal coronary angioplasty (PTCA) and were compared with 338 patients having isolated coronary artery bypass surgery. Patients undergoing PTCA had a shorter duration of angina, a lower number of prior myocardial infarctions, and better left ventricular function (p less than 0.01); PTCA was considered initially successful in 87% (295/339) of patients. Repeat angioplasty was performed in 18% of patients (34/339), with a successful outcome in all but 1. The most common finding at operation in those with failed angioplasty and urgent or emergency revascularization was dissection of an atheromatous plaque. There were 28 early failures (operation performed within 24 hours) and 24 late failures (operation at more than 24 hours), for early and late failure rates of 8.3% and 7.1%, respectively. Although the cumulative frequency of new Q-waves in the entire angioplasty series was low (2.7%), the incidence was high in those with angioplasty failure and subsequent operation (18%), and was significantly greater than in patients having elective coronary bypass (3.6%). Use of inotropic agents and lidocaine treatment for ventricular arrhythmias was also significantly higher in patients with unsuccessful PTCA who required operation than in those undergoing elective bypass (10% versus 3% and 10% versus 1.5%, respectively; p less than 0.01). Eleven of the 28 patients who were early failures were totally revascularized within 2 hours of angioplasty failure. Facilities and staff available for expedient revascularization accounted for the low morbidity and lack of mortality in PTCA failures.

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.

The porcine bioprosthesis. A review of 1,000 consecutive patients undergoing cardiac valve replacement.

Early and late experience with 1,000 patients undergoing porcine xenograft replacement of cardiac valves from 1974 through 1981 at Emory University Hospital is presented. Hemodynamic performance of the modified orifice Hancock and the Carpentier-Edwards valves has been quite satisfactory. There has been a low incidence of thromboembolism in the absence of routine anticoagulation. Less than 20 per cent of our patients are anticoagulated long-term, the primary indication being chronic artrial fibrillation. Endocarditis has developed in 0.7 per cent of patients, an incidence comparing most favorably with that of mechanical prostheses. Valve dysfunction secondary to primary tissue failure is a definite problem. The highest incidence of tissue failure occurred in young patients after six years of implantation. Detailed analysis of long-term patient survival showed a low incidence of valve related deaths. The porcine xenograft is a satisfactory prosthesis for cardiac valve replacement. Our data suggests its use should be limited to older patients or to patients in whom anticoagulation is contraindicated. It should be explained to all patients that long-term durability is unknown and that re-replacement of these bioprostheses within a decade is quite likely.

Trends in the treatment of coronary disease today. Selective use of PTCA and bypass surgery.

Selection and treatment of patients with ischemic heart disease is presently undergoing an evolutionary trend. Percutaneous transluminal coronary angioplasty (PTCA) has been recommended as the initial procedure for many patients with coronary artery disease (CAD), thus possibly redefining candidates for coronary bypass surgery (CABS). Between October 1980 and June 1982, 777 patients having PTCA and 2068 patients having CABS were analyzed for differences in clinical presentation, complications, and early outcome. Patients having CABS were significantly older, had a higher incidence of hypertension (46% vs. 32%), more multivessel disease (80% vs. 12%), and poorer left ventricular function (nl. wall motion = 88% vs. 52%). The incidence of myocardial infarction in patients after PTCA was 1.0% (8/777). Emergency CAB was required in 5.3% of patients following PTCA. There were no deaths following the angioplasty procedure and 25 deaths in 2068 patients having CABS (hospital mortality rate = 1.2%). Since 1973, there has been a progressive decline in hospital mortality rate (now, less than 1%), postoperative infarction (now, 3%), requirement for inotropic drugs (now, 5%) and frequency of IABP (less than 1%). Increasing ability to achieve complete revascularization now means improved survival and freedom from angina with CAB surgery. PTCA and CAB are both procedures that may be used effectively for selected patients, depending on clinical presentation, extent of CAD, and left ventricular function (LVF). Careful patient selection affords the opportunity for use of PTCA in patients with single-vessel disease (SVD) and good LVF and CABS in patients with multivessel disease, regardless of LVF. Symptomatic patients with SVD and total vessel occlusion are not candidates for PTCA. Our data demonstrate that both PTCA and CABS may be accomplished with very low perioperative complications and hospital mortality.

Nitroglycerin as an adjunct to hypothermic hyperkalemic cardioplegia.

The efficacy of nitroglycerin as an adjunct to hyperkalemic hypothermic cardioplegia was assessed by measurement of changes in coronary vascular resistance. Thirty patients undergoing coronary artery bypass grafting were studied. During a 1000 ml infusion of cardioplegia, a bolus of 1 mg of nitroglycerin or control solution was injected while the infusion rate was kept constant. Measurement of aortic root pressure allowed calculation of coronary vascular resistance. There was a mean decrease of 21.2% in coronary vascular resistance after a bolus of 1 mg of nitroglycerin was injected in the study group (p less than .001, n = 15); there was no significant change in resistance in the control group. There was also no significant change in systemic vascular resistance in either group. A retrospective blind analysis of the anatomic angiographic features of the heart with a quantitative assessment of both coronary stenoses and coronary collaterals was made. There was no correlation between coronary scores and preinjection coronary vascular resistance. There was also no correlation between collateral scores and the change in coronary vascular resistance with nitroglycerin. These results suggest that nitroglycerin is an effective coronary vasodilator when used as an adjunct in hypothermic hyperkalemic cardioplegia and that baseline coronary vascular resistance or change in coronary vascular resistance with nitroglycerin cannot be predicted on the basis of current assessments of coronary angiograms.

Clinical, anatomic and functional descriptors influencing morbidity, survival and adequacy of revascularization following coronary bypass.

Clinical data on 3,479 consecutive patients having coronary bypass surgery were retrospectively analyzed. Perioperative complications, incomplete revascularization, and reduced long-term survival could frequently be correlated with manifestations of myocardial damage. Patients with triple vessel and left main coronary disease had a greater frequency of inotropic requirements than did patients with single or double vessel disease (7.9% and 8.6% vs. 3.8% and 4.2%). Inotropic requirements in the perioperative period were significantly increased for patients with preoperative left ventricular dysfunction; a history of heart failure or multiple infarctions did not significantly increase the incidence of inotropic requirements. Presence of previous myocardial infarction, heart failure, or left ventricular contraction abnormalities significantly decreased the ability to achieve complete revascularization with bypass grafting. Hospital mortality since 1976 has been 0.8% (25/3,040). Hospital mortality was significantly increased by history of myocardial infarction, hypertension, heart failure, extent of anatomic disease, presence of preoperative ST-T wave changes, and severe abnormalities of left ventricular function. Hospital mortality in patients with ejection fraction 0.35. Anginal pattern, history of hypertension, previous myocardial infarction, preoperative heart failure all significantly affected long-term survival. Occurrence of perioperative myocardial infarction did not adversely influence long-term survival. Patients with normal left ventricular function had excellent 42 month survival regardless of vessel disease (95%, 96%, and 94% for single, double, and triple vessel disease, respectively). Survival was significantly less for such patients with abnormal left ventricular function. Inability to achieve complete revascularization did not adversely affect hospital mortality, but did significantly reduce late survival. The important effect which complete revascularization had on long-term survival appeared to increase with increasing severity of coronary disease. Although bypass grafting improves survival in patients with multivessel disease and left ventricular dysfunction, the benefits appear to be significantly reduced once manifestations of left ventricular damage have occurred.

Concomitant carotid and coronary artery reconstruction.

Data are presented on 68 patients who underwent concomitant carotid endarterectomy (CE) and coronary artery bypass surgery (CAB) at Emory University Hospital from January 1974 to February 1981. This group is then compared with a randomly selected, matched population without known carotid disease who underwent CAB alone. Asymptomatic bruit was the reason for investigation in 40 patients (59%); another 23 patients (34%) experienced transient cerebral ischemic attacks (TIAs); and five patients (7%) had TIA and prior stroke. Carotid stenoses (>75% luminal narrowing) were demonstrated as follows: isolated left, 24 patients; isolated right, 27 patients; and bilateral lesions, 16 patients. One patient had innominate artery stenosis. Associated total occlusion of one or both vertebral arteries was demonstrated in six patients. Ninety-seven per cent of patients had disabling angina pectoris prior to operation; the angina was unstable in 57%, 15% had congestive heart failure, and 54% had had at least one prior myocardial infarction (MI). Single-vessel coronary disease was present in 12.5% of patients, double in 37.5%, triple in 41.1%, and left main stenosis in 9%; 43% of patients had abnormal ventricular contractility. CE was performed on 67 patients (36 left and 31 right); aortocarotid bypass was performed on one. The CE procedures were performed immediately prior to the sternotomy for CAB under the same anesthesia. CAB consisted of single bypass in eight patients (11.8%); double in 16 patients (23.5%); triple in 22 patients (32.4%); and quadruple or more in 22 patients (32.4%) (mean = 2.9 grafts per patient). There was no hospital mortality. Perioperative MI occurred in 2.0% and stroke with residual deficit in 1.3%. Cumulative survival is 98.5% at two years. Sixty-three patients (92%) reported improvement or elimination of anginal symptoms after operation. Rehospitalization for stroke was necessary in 3.7% patients. Postoperative activity levels are; self-care only, 3.9%; normal daily activity only, 17.6%; moderate exercise capability, 45%; and vigorous exercise capability, 33%. Comparison was made with a group of 84 randomly selected patients who underwent CAB alone during the same time interval. Data revealed no significant difference between the groups regarding sex, angina subset, ventricular function, coronary anatomy, vessels grafted, perioperative stroke or MI, mortality, or postoperative activity capability. Older age (59.8 vs. 55.6, p < 0.01) and less complete coronary revascularization possible (66 vs. 84%, p < 0.05) in the CECAB group were the only significant differences. Carotid stenosis co-existing in patients requiring CAB should be concomitantly corrected with the same risk and results expected from CAB alone.