Vallee L. Willman

Results of internal thoracic artery grafting over 15 years: single versus double grafts

One hundred consecutive patients who had coronary artery bypass grafting using both internal thoracic arteries (ITAs) and saphenous veins, operated on during a 3-year period between 1972 and 1975, have been compared retrospectively with a series of 100 patients operated on during the same period who had one ITA graft along with saphenous vein grafts. The two groups were similar with respect to age, sex, risk factors for coronary artery disease, angina class, extent of coronary artery disease, left ventricular function, number of coronary bypass grafts performed, and completeness of revascularization. Single ITA operative mortality was 2% and double ITA, 9% (p = NS). The mean follow-up of hospital survivors was 14.4 +/- 2.7 years; all but 7 patients had follow-up for at least 10 years. At 13 years, the actuarial patency of the right ITA was 85% and the left ITA, 82%. These data strongly suggest a survival benefit for patients with double ITA grafts among hospital survivors (74% versus 59%; p = 0.05). Patients receiving two ITA grafts had a significant freedom from subsequent myocardial infarction (75% versus 59%, p less than 0.025), recurrent angina pectoris (36% versus 27%, p less than 0.025), and subsequent total ischemic events (32% versus 18%, p less than 0.01). These data also suggest improved freedom from coronary artery interventional therapy (percutaneous transluminal coronary angioplasty and reoperation) when two ITA grafts were used. These results support the use of bilateral internal thoracic artery grafting in selected patients.

The changing profile of the patient undergoing coronary artery bypass surgery

The first 100 consecutive patients undergoing isolated coronary artery bypass surgery in 1975 were evaluated with respect to the incidence of operative risk factors and outcome. When compared with an identically selected group from 1985, there was significant worsening of the preoperative condition over the decade with regard to mean age (p less than 0.0005), presence of congestive heart failure (p less than 0.05), left ventricular dysfunction (p less than 0.05), severity of coronary artery disease (p less than 0.001) and incidence of emergency operation (p less than 0.05). More patients in 1985 had associated medical diseases such as diabetes (p less than 0.01) and chronic lung disease (p less than 0.005). There was an increase in the occurrence of vascular diseases (hypertension, renal dysfunction, peripheral vascular and cerebrovascular disease) (p less than 0.05). Overall operative mortality increased from 1 to 8% (p less than 0.05) over the decade. Despite the deterioration in the clinical profile of the patient undergoing coronary bypass surgery, elective procedures were still performed with low mortality. The significant increase in overall mortality was chiefly in patients undergoing emergency operation (p less than 0.05). There were also increases in operative morbidity including low output syndrome (p less than 0.01) and respiratory (p less than 0.005) and neurologic (p = 0.06) complications.

The Importance of Biventricular Failure in Patients with Postoperative Cardiogenic Shock

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

Cardiac Norepinephrine Stores and the Contractile State of Heart Muscle

In order to assess the role played by endogenous norepinephrine (NE) stores in the intrinsic contractile state of cardiac muscle, the right ventricular papillary muscles from normal cats and cats with cardiac NE depletion produced by chronic cardiac denervation or reserpine pretreatment were studied. The contractile state of NE-depleted ventricular myocardium was found to be normal. The resting and active length-tension curves, the forcevelocity relations, and the augmentation of isometric tension achieved by paired electrical stimulation and by increasing frequency of contraction were not depressed in either group of NE-depleted muscles. Similarly, no changes in the absolute refractory period and electrical excitability were observed. It is concluded that cardiac stores of NE are not fundamental for maintaining the intrinsic contractile state of the myocardium. Further, release of endogenous NE from cardiac muscle does not appear to play an essential role in the mediation of the positive inotropic effects of increasing frequency of contraction or of sustained postextrasystolic potentiation.

Myocardial Revascularization in Women

During the period January, 1970, through June, 1977, 1,541 patients underwent coronary artery bypass grafting; 241 of them were women (15.6%). Operative mortality rates for the entire study were 2.4% in men and 3.7% in women, but they showed a marked decline in women during 1975 to mid-1977, with only 2 deaths in 140 patients (1.4%). Women comprised a larger percentage of patients (16.7%) in these later years. Women were slightly older, received fewer grafts, had better preservation of ventricular function on preoperative studies, and had more severe anginal symptoms than men. Patency rates were significantly lower in women at 1 month, 1 year, and 3 years. Five-year survival was not significantly different between women (88.3%) and men (93.5%). Many of these findings may be explained on the basis of women having smaller coronary arteries than men. These favorable results differ from earlier reports of higher mortality rates in women and indicate that myocardial revascularization should not be withheld from female patients.

Major complications of median sternotomy

Major sternal infections developed in eleven of 1,550 patients undergoing median sternotomy for operations on the heart. Nine patients had myocardial revascularization, six with internal mammary artery as the conduit. Seven of these patients have been salvaged by aggressive local wound management and systemic support. These survivors have a good outlook for treatment of their basic cardiac disease.

Coronary artery bypass surgery in patients aged 80 years or older

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.

Blood Flow in the Diabetic Leg

Femoropopliteal bypass grafting with reversed saphenous vein was performed in 47 nondiabetic and 27 diabetic extremities. Graft flow was measured with an electromagnetic flow probe before and after injection of 15 mg of papaverine into the graft. Basal flow (nondiabetic, 74 ± 6; diabetic, 76 ± 11 ml/min) was similar in the two groups. Peak flow was significantly higher in the nondiabetic group (217 ± 14 ml/min) than in the diabetic group (169 ± 18 ml/min, P < 0.05), and the outflow tract was significantly better in the nondiabetics (12.2 ± 0.5) than in the diabetics (8.6 ± 0.7, P < 0.001). When flow was related to the quality of the outflow tract, there was no significant difference between nondiabetics and diabetics. Diabetics with occlusive vascular disease have greater involvement of the tibial and peroneal arteries than do nondiabetics. Vascular reactivity is not significantly impaired, and arterial reconstruction should not be withheld on the basis of anteriolar-capillary involvement.

Vascular complications from intraaortic balloons: Risk analysis

PURPOSE The purpose of this study was to assess the incidence of and predictors for vascular complications in patients who required perioperative intraaortic balloon pump (IABP) support. METHODS Data from 580 patients collected with a retrospective review were statistically analyzed with 25 perioperative parameters, and significant variables were evaluated with multivariate analysis. These data were also statistically compared with data from a 1983 study from our institution. RESULTS Vascular complications occurred in 72 patients (12.4%). The three aortic perforations were fatal. Ipsilateral leg ischemia occurred in 69 patients. Of these, ischemia was resolved in 82% of patients by IABP removal (21), thrombectomy (21), vascular repair (13), fasciotomy (2), or without intervention (2). Six patients died with the intraaortic balloon in place. Four patients required amputation for ischemia, but all survived. CONCLUSIONS Vascular complications were not predictive of operative death (p = 0.26). Risk analyses with 25 perioperative parameters revealed that history of peripheral vascular disease, female sex, history of smoking, and postoperative insertion were independent predictors of vascular complications. However, most risk for vascular complications cannot be explained by these factors because of a low R2 value. Compared with the results of our 1983 study, the incidence of IABP-related complications has not changed, but the severity of complications has decreased significantly, and IABP-induced death has decreased significantly.

Use of the Pierce-Donachy ventricular assist device in patients with cardiogenic shock after cardiac operations.

In spite of recent improvements in cardiac surgery, a small percentage of patients have severe postcardiotomy ventricular failure refractory to drugs and the intraaortic balloon. In our experience, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most effective devices for these patients. Since 1981, 30 patients aged 15 to 71 years (mean age, 52 years) with profound cardiogenic shock refractory to conventional therapy after cardiotomy were supported with the Pierce-Donachy ventricular assist device. Fourteen required left ventricular support, 7 needed right ventricular support with an intraaortic balloon, and 9 had biventricular assistance. Duration of support ranged from three hours to 22 days (mean length, 3.6 days). Seven of the first 11 patients seen died in the operating room of bleeding, biventricular failure, or both. However, 16 patients (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (37%) were discharged. Of the last 19 patients in the series, 47% survived. Factors affecting survival were myocardial infarction (75%) and renal failure (90%). Common complications were bleeding (73%) and biventricular failure (83%).