Ronald M. Weintraub

Congenital coronary arteriovenous fistula. Report of 13 patients, review of the literature and delineation of management.

Thirteen new patients and 174 patients previously reported with coronary arteriovenous fistula (CAVF) were reviewed to delineate the course and management of CAVF and to clarify the role of surgical ligation in the young asymptomatic patient. Patients were grouped according to age: 99 patients (four new and 95 reported) were less than 20 years old and 88 (nine new and 79 reported) were greater than or equal to 20 years old. Of those under 20 years of age, 19% had preoperative symptoms or CAVF-related complications, including congestive heart failure (CHF) in 6%, subacute bacterial endocarditis in 3% and death in one patient. Seventy-six patients younger than 20 years old had CAVF ligation with only one significant complication. In contrast, 63% of the older group and all of our nine older patients had preoperative symptoms or complications, including CHF in 19%, SBE in 4%, myocardial infarction (MI) in 9%, death in 14% and fistula rupture in one patient. Of the 43 ligated older patients, 23% had surgical complications, including MI in three and death in three. Mean pulmonic-to-systemic flow in the entire group was 1.6:1 and did not differ significantly in those with or without symptoms or complications. One of our patients and one previously reported had spontaneous CAVF closure. In summary, early elective ligation of CAVF is indicated in all patients because of the high incidence of late symptoms and complications and the increased morbidity and mortality associated with ligation in older patients.

Determination of Etiologic Mechanisms of Strokes Secondary to Coronary Artery Bypass Graft Surgery

Background and Purpose— Current research focused on stroke in the setting of coronary artery bypass graft (CABG) surgery has missed important opportunities for additional understanding by failing to consider the range of different stroke mechanisms. We developed and implemented a classification system to identify the distribution and timing of stroke subtypes. Methods— We conducted a regional study of 388 patients with the diagnosis of stroke after isolated CABG surgery in northern New England from 1992 to 2000. Data were collected on patient and disease characteristics, intraoperative and postoperative care, and outcomes. Stroke etiology was classified into 1 of the following: hemorrhage, thromboembolic (embolic, thrombotic, lacunar), hypoperfusion, other (subtype not listed above), multiple (≥2 competing mechanisms), or unclassified (unknown mechanism). The reliability of the classification system was determined by percent agreement and &kgr; statistics. Results— Embolic strokes accounted for 62.1% of strokes, followed by multiple etiologies (10.1%), hypoperfusion (8.8%), lacunar (3.1%), thrombotic (1.0%), and hemorrhage (1.0%). There were 54 strokes with unknown etiology (13.9%). There were no strokes classified as “other.” Nearly 45% (105/235) of the embolic and 56% (18/32) of hypoperfusion strokes occurred within the first postoperative day. Conclusions— We used a locally developed classification system to determine the etiologic mechanism of 388 strokes secondary to CABG surgery. The principal etiologic mechanism was embolic, followed by stroke having multiple mechanisms and hypoperfusion. Regardless of mechanism, strokes predominantly occurred within the first postoperative day.

Effect of Diabetes and Associated Conditions on Long-Term Survival After Coronary Artery Bypass Graft Surgery

Background—The effects of diabetes on short-term results of coronary artery bypass graft (CABG) surgery are known, but less is known about the long-term effects of diabetes and diabetic-related sequelae for patients undergoing this surgery. We studied the 10-year survival of nondiabetic and diabetic patients undergoing CABG surgery. Methods and Results—A prospective regional cohort study was conducted of 36 641 consecutive isolated CABG patients in northern New England from 1992 through 2001. Patient records were linked to the National Death Index to assess mortality. There were 154 140 person-years of follow-up and 5779 deaths. Kaplan–Meier techniques were used. Survival was stratified into three categories: no diabetes, diabetes without peripheral vascular disease and renal failure, and diabetes with peripheral vascular disease and/or renal failure. The overall annual incidence rate of death was 3.7 deaths per 100 person-years. Annual incidence rates for nondiabetic subjects and diabetic subjects were similar: 3.1 deaths per 100 person-years and 4.4 deaths per 100 person-years, respectively. The annual incidence rate for diabetic subjects with renal failure, peripheral vascular disease, or both was 9.4 deaths per 100 person-years. The log-rank test showed that the survival curves were significantly different (P<0.001). Conclusion—Patients that have diabetes without the sequelae of renal failure and/or peripheral vascular disease have long-term survival similar to but slightly less than patients without diabetes who undergo CABG surgery. Survival of CABG surgery patients with diabetes is greatly affected by associated comorbidities of peripheral vascular disease and renal failure. This knowledge may help guide the patient as well as the cardiologist and cardiac surgeon in making appropriate decisions in these critically ill patients.

In vivo coronary angioscopy.

The feasibility of in vivo coronary angioscopy was tested utilizing a 1.8 mm angioscope in vessels where blood had been replaced by optically clear liquids, including a new perfluorocarbon emulsion. After trials in postmortem canine and human coronary arteries, in vivo intraluminal visualization was accomplished in the dog with a catheterization technique and in patients during open heart surgery. The results demonstrate the feasibility and potential clinical usefulness of direct visualization of intravascular anatomy and disease, analogous to endoscopy of other organ systems.

Long-term survival of dialysis patients after coronary bypass grafting

BACKGROUND Dialysis patients are undergoing coronary artery bypass grafting (CABG) with increasing frequency. The long-term effect of preoperative dialysis-dependent renal failure on mortality after CABG has not been well studied. METHODS We conducted a prospective regional cohort study of 15,574 consecutive patients undergoing isolated CABG in northern New England from 1992 to 1997. Patient records were linked to the National Death Index to assess mortality. Five-year survival and adjusted hazard ratios were calculated. RESULTS During 32,589 person-years of follow-up 1298 deaths were recorded. Renal failure was present in 283 patients (1.8%), and 67.8% of patients with renal failure also had diabetes or peripheral vascular disease (PVD). The annual death rate was 3.8% for nonrenal failure patients, 16.9% for all renal failure patients, 7.7% for renal failure patients without diabetes or PVD, and 23.0% for renal failure patients with diabetes or PVD. Five-year survival was 83.5% for nonrenal failure patients, 55.8% for all renal failure patients, 78.5% for renal failure patients without diabetes or PVD, and 42.2% for renal failure patients with diabetes or PVD. After adjustment for differences in base line patient and disease characteristics, renal failure patients without diabetes or PVD had a statistically nonsignificant 57% increase rate of death compared with those without renal failure; renal failure patients with diabetes or PVD had more than a fourfold increased risk of death. CONCLUSIONS After adjustment for other risk factors, renal failure remains a highly significant predictor of decreased long-term survival in CABG patients. Patients with renal failure plus diabetes or PVD are at especially high risk of death.

Pericardial modulation of right and left ventricular diastolic interaction.

We studied the effects of the right ventricle (RV) and pericardium on left ventricular (LV) diastolic pressure-volume (P-V) relations in the normothermic isolated blood-perfused dog heart. Studies were performed at a constant heart rate (atrial pacing at 120 beats/min) with a coronary perfusion pressure of 100 mm Hg. LV volume was directly controlled by an intraventricular balloon, whereas RV filling pressure was increased stepwise from zero to 20 mm Hg. During progressive increases in RV filling pressure, with the pericardium intact, the LV diastolic P-V relations were shifted up and to the left; this leftward shift of the LV diastolic P-V relation was associated with an increase in the modulus of LV chamber stiffness. Closing the small pericardial incisions with sutures significantly increased this effect. In the absence of the pericardium, progressive filling of the RV resulted in minor changes in LV diastolic P-V relations. Only when the RV filling pressure was markedly elevated (20 mm Hg) was there a significant effect on LV diastolic pressure. The pericardium has a small but significant effect on LV diastolic P-V relations at physiological RV filling pressures, and this effect becomes considerable at high RV filling pressures. The RV influence on LV diastolic P-V relations is significantly modulated by the presence of tightness of the pericardium. Circ Res 48: 233-238, 1981

Medically refractory unstable angina pectoris. I. Long-term follow-up of patients undergoing intraaortic balloon counterpulsation and operation.

Of 82 patients with medically refractory unstable angina pectoris seen between October 1972 and January 1978, 60 patients underwent a combination of intraaortic balloon pump counterpulsation, cardiac catheterization and coronary revascularization. Most patients had atherosclerotic involvement of the vessels of the anterior left ventricular wall, 48 patients (80 percent) had abnormalities of left ventricular wall contraction and 22 patients (36 percent) had evidence of acute myocardial injury. One operative and one late death occurred. The perioperative infarction rate was 5 percent. Survivors, followed up for 3 to 63 months (mean 31 months), have done remarkably well; 77 percent are considered employable,and more than 90 percent are in functional class I or II.

Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement.

Dynamic left ventricular outflow tract obstruction developed in a patient in whom the anterior leaflet was retained at mitral valve replacement. It was caused by systolic anterior movement of the native anterior leaflet. Reduced outflow tract diameter, resulting from both posterior displacement of the septum and anterior displacement of the native anterior leaflet by porcine stents, was likely instrumental in promoting dynamic obstruction.

Cutaneous closure after cardiac operations : A controlled, randomized, prospective comparison of intradermal versus staple closures

OBJECTIVE To determine the difference in wound complication and infection rates between suture and staple closure techniques applied to clean incisions in coronary bypass patients. BACKGROUND The true incidence of postoperative wound complications, and their correlation with closure techniques, has been obscured by study designs incorporating small numbers, retrospective short follow-up, uncontrolled host factors, and narrowly defined complications. METHODS Sternal and leg wounds were studied prospectively, each patient serving as his or her own control. Two hundred forty-two patients with sternal and saphenous vein harvest wounds had half of each wound closed with staples and the other half with intradermal sutures (484 sternal and 516 leg segments). Wound complications were defined as drainage, erythema, separation, necrosis, seroma, or infection. Infections were identified in the subset having purulent drainage, antibiotic therapy, or debridement. Wounds were examined at discharge, at 1 week after discharge, and at 3 to 4 weeks after operation. Patient preferences for closure type were assessed 3 to 4 weeks after operation. RESULTS Neither leg nor sternal wounds had a statistically significant difference in infection rate according to closure method (leg sutured = 9.3% vs. leg stapled = 8.9%; p = 0.99, and sternal sutured = 0.4% vs. sternal stapled = 2.5%; p = 0.128). There was, however, a greater complication rate in stapled segments (leg stapled = 46.9% vs. leg sutured = 32.6%; p = 0.001, and sternal stapled = 14.9% vs. sternal sutured = 3.7%; p = 0.00005). Sutures were favored over staples among patients who expressed a preference (sternal = 75.6%, leg = 74.6%). CONCLUSIONS With the host factors controlled by pairing staples and sutures in each patient, we demonstrated a similar incidence of infection but a significantly lower incidence of total wound complications with intradermal suture closure than with staple closure.

Neutrophil adhesion blockade with NPC 15669 decreases pulmonary injury after total cardiopulmonary bypass.

BACKGROUND Total cardiopulmonary bypass, in an ovine model, is associated with increased pulmonary thromboxane A2 production, cellular sequestration of white cells and platelets, transient pulmonary hypertention, and increased lung lymph flow and lymph protein clearance when compared with respective findings with partial cardiopulmonary bypass. This study evaluates the effect of neutrophil adhesion blockade on lung injury after cardiopulmonary bypass. METHODS Two groups of anesthetized sheep were placed on total cardiopulmonary bypass without assisted ventilation. One group of seven sheep was treated before and during total cardiopulmonary bypass with the neutrophil adhesion blocker NPC 15669. A second group of seven sheep did not receive NPC 15669 treatment before total cardiopulmonary bypass. A third group of seven sheep was treated with NPC 15669 before initiation of partial cardiopulmonary bypass with continued assisted ventilation. Aortic occlusion and hypothermia were not used. After 90 minutes all sheep were separated from cardiopulmonary bypass, with resumption of assisted ventilation and pulmonary arterial flow. After 30 minutes the left atrial pressure was elevated mechanically. Hemodynamics, thromboxane A2 levels, platelet levels, and white blood cell and plasma protein concentrations were measured before cardiopulmonary bypass and afterwards at four 15-minute intervals. Samples were taken from the right and left atria simultaneously. Lung lymph protein levels and flow were measured before and after cardiopulmonary bypass at two 30-minute intervals. RESULTS In the total cardiopulmonary bypass group not treated with NPC 15669 signs of lung injury developed after cardiopulmonary bypass. Animals treated with NPC 15669 did not manifest a similar degree of lung injury after either partial or total cardiopulmonary bypass. Increased pulmonary vascular resistance did not develop in treated sheep nor did sequestration of platelets or white blood cells occur. Despite the drug, increased pulmonary capillary permeability after total cardiopulmonary bypass persisted, but was reduced. CONCLUSIONS Compared with unmodified total cardiopulmonary bypass, blockade of neutrophil adhesion with NPC 15669 reduces, but does not entirely eliminate, lung derangement after total cardiopulmonary bypass.