Transmyocardial laser revascularization combined with coronary artery bypass grafting: a multicenter, blinded, prospective, randomized, controlled trial.

OBJECTIVE: We sought to assess the safety and efficacy of transmyocardial revascularization combined with coronary artery bypass grafting in patients not amenable to complete revascularization by coronary bypass alone. METHODS: A total of 263 patients whose standard of care was coronary artery bypass grafting and who had one or more ischemic areas not amenable to bypass grafting were prospectively randomized to receive coronary bypass of suitable vessels plus transmyocardial revascularization to areas not graftable (n = 132) or coronary bypass alone with nongraftable areas left unrevascularized (n = 131). Group preoperative demographics and operative characteristics were similar. RESULTS: The operative mortality rate after coronary bypass/transmyocardial revascularization was 1.5% (2/132) versus 7.6% (10/131) after coronary bypass alone (P =.02). Patients undergoing both coronary bypass and transmyocardial revascularization required less postoperative inotropic support (30% vs 55%, P =.0001) and had a trend toward fewer insertions of intra-aortic balloon pumps (4% vs 8%, P =.13) than did patients having coronary bypass alone. Multivariable predictors of operative mortality were coronary artery bypass alone (odds ratio, 5.3; 95% confidence interval, 1.1-25.7; P =.04) and increased age (odds ratio, 1.1; 95% confidence interval, 1. 0-1.2; P =.03). One-year Kaplan-Meier survival (95% vs 89%, P =.05) and freedom from major adverse cardiac events defined as death or myocardial infarction (92% vs 86%, P =.09) favored the combination of coronary bypass and transmyocardial revascularization. Baseline to 12-month improvement in angina and exercise treadmill scores was similar between groups. CONCLUSIONS: In a prospective, randomized, multicenter trial, transmyocardial revascularization combined with coronary artery bypass grafting in patients not amenable to complete revascularization by coronary bypass alone was safe; however, angina relief and exercise treadmill improvement were indistinguishable between groups at 12 months of follow-up. Operative and 1-year survival benefits observed after adjunctive transmyocardial revascularization require confirmation by a larger validation study, which is ongoing.

Mitral valve repair combined with aortic valve replacement.

BACKGROUND AND AIMS OF THE STUDY: Combined aortic and mitral valve replacement continues to result in significant morbidity and mortality. Although mitral repair has improved the results of mitral valve surgery, its influence on combined aortic valve replacement has not been assessed. METHODS: We reviewed 38 consecutive patients who underwent aortic valve replacement (AVR) and mitral repair (MR) between 1985 and 1995. The average age was 57 years; 20 were men and 18 women. Nineteen patients were considered high risk: six had previous cardiac surgery, three were on chronic dialysis, two required emergency surgery for low output syndrome, one had a chronic tracheotomy for chronic lung disease, and seven had left ventricular ejection fraction < 30%. MR consisted of ring application alone in 28 patients, chordal shortening in nine, posterior leaflet transfer in six and posterior leaflet resection in four. AVR was accomplished with 21 bioprostheses, 14 mechanical and three allograft valves. The mean (+/-SD) cross-clamp time was 133 +/- 41 min. Additional procedures included coronary bypass in six patients and tricuspid procedures in three. RESULTS: There were no operative deaths. Six patients died between 4 and 73 months postoperatively. Patient survival was 75% five and 67% 10 years after surgery. The causes of death were heart failure (two cases), and respiratory failure, drug overdose, electrolyte imbalance and unknown (one each). Logistic risk analysis was significant for females and rheumatic valve disease, bacterial endocarditis, and degenerated valve patients. During follow up there were no valve failures or endocarditis, but three embolic episodes occurred without permanent sequel. CONCLUSIONS: With increased surgical expertise, improved myocardial protection of MR combined with AVR offers excellent short- and long-term results, optimal chordal preservation, no valve failure and no endocarditis; it is the ideal choice where anti-coagulation is contraindicated. The prolonged cross-clamp time was well tolerated.

Sensing lead-related complications in patients with transvenous implantable cardioverter-defibrillators.

The widespread use of the redesigned Endotak lead (CPI, St. Paul, Minnesota), which combines transvenous pacing, sensing, and defibrillation on a single transvenous lead in patients receiving transvenous implantable cardioverter-defibrillators (ICDs), has reduced morbidity and shortened length of hospital stay after ICD implantation. We describe the incidence and management of Endotak sensing lead-related failures in a series of 348 consecutive patients from 4 institutions who underwent implantation between 1990 and 1995. We retrospectively reviewed the databases for patients receiving an ICD with an Endotak lead for the incidence of lead-related sensing abnormalities. Ten patients (2.8%) with lead-related sensing abnormalities were detected at a mean of 15 +/- 11 months after ICD implantation. Sensing abnormalities were detected in 6 patients after they received inappropriate shocks. Noise or oversensing was noted in 7 patients from interrogation of the devices' data logs. Eight patients had a new transvenous sensing lead placed, 1 patient had a new Endotak lead placed, and 1 had a chronic pacemaker sensing lead converted to function as a sensing lead. No further sensing problems were noted in 8 of 10 patients during a mean follow-up of 14 +/- 8 months. The site of the sensing lead failure was localized to the subrectus pocket in 5 patients and to the clavicle-first rib area in 3 patients; it was undetermined and presumed to be in the clavicle-first rib area in the other 2 patients. One patient had late failure of the defibrillation lead. We conclude that Endotak sensing lead failure does not require insertion of a new Endotak lead, but can be managed with close follow-up and insertion of a new transvenous sensing lead. Endotak lead fractures are frequently localized to the ICD pocket.

Mitral valve repair in patients over the age of 70 years.

The question of whether to repair or replace the mitral valve in the elderly remains unanswered. The purpose of our study is to describe our experience with mitral valve repair (MVR) using Carpentier's technique in patients 70 years and older. Fifty consecutive patients underwent MVR between 1984-1992. There were 30 female patients. All had 2 + or more mitral regurgitation (MR). The valve pathology included ischemic (n = 28), myxomatous (n = 7) and rheumatic (n = 6), leaflet prolapse (n = 11) and healed bacterial endocarditis (n = 3). The clinical findings included: myocardial infarction (n = 17), congestive heart failure (n = 18), atrial fibrillation (n = 14) and pulmonary hypertension (n = 10). The surgical technique involved placement of a Carpentier ring (n = 41) or Duran ring (n = 3), resection of leaflets (n = 9), shortening of the chordae (n = 8) and commissurotomy (n = 6). At surgery, coronary bypass was carried out in 32 patients while the aortic valve was replaced in five and repaired in one. Postoperative complications included atrial fibrillation (n = 14), transient neurologic events (n = 4), heart block requiring pacemaker (n = 3) and prolonged intubation (n = 4). Echocardiogram carried out postoperatively showed 2 + MR in three patients, 1 + in four, and a trace or none in the remaining (n = 39). No patient required re-operation for MR. Three patients (6%) died within 30 days after surgery due to low output (n = 1), malignant ventricular arrhythmia (n = 1) and heart block with cardiac arrest (n = 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Deep hypothermic arrest and left thoracotomy for repair of difficult thoracic aneurysms.

Seven patients with complex thoracic aortic aneurysms were operated on using profound hypothermia and circulatory arrest through a left thoracotomy. Three patients had false aneurysms, 2 had large aneurysms precluding access for proximal control, 1 patient had had previous hemiarch replacement, and 1 patient had a thoracoabdominal aneurysm. All patients were cooled on partial cardiopulmonary bypass until the electroencephalogram was isoelectric (approximately 15 degrees C rectal temperature). Circulatory arrest times ranged from 7 to 56 minutes (median, 34 minutes). There was one death due to cardiac failure, and paraplegia developed in 1 patient. The 6 survivors are otherwise well at a median of 12 months postoperatively. Hypothermia and circulatory arrest is an invaluable technique for the treatment of complex aortic aneurysms requiring left thoracotomy for resection. The techniques employed are described and the indications for their use are discussed.

Management of aortic cannulation site blowouts.

An alternative technique of handling the aortic cannulation site blowout is described. The cannulation site is excluded with a side-biting clamp. The area is excised. Pericardial patch is sewn in to cover the defect.

A prospective study of the clinical utility of lymphocyte monitoring in the cardiac transplant recipient.

Monitoring peripheral lymphocytes for changes in antigen expression or subpopulations was performed by flow cytometry in an attempt to identify infection or rejection in cardiac transplantation recipients (CTRs). In this study, 32 cardiac transplantation recipients were followed prospectively, and the results of 274 lymphocyte analyses for transferrin receptor expression, an indicator of lymphocyte activation, and CD4/CD8 lymphocyte ratios were correlated with the patient's clinical status, e.g., infection (early or late), rejection (mild, moderate, or severe), or quiescence. The percentage of lymphocytes expressing the transferrin receptor (%TR+) increased significantly during all stages of infection (2.9%, P = 0.02), or stratified into early (2.7%, P = 0.03) or late stage infection (2.6%, P = 0.03). The increase in %TR+ lymphocytes was also noted during mild (2.8%, P = 0.01) and moderate (3.0%, P = 0.008) rejection. The specificity and positive predictive value of an increased %TR+ lymphocyte was 97% and 93%, respectively, during early infection; 92 and 71%, respectively, during mild rejection; and 85 and 80%, respectively, during moderate rejection. The CD4/CD8 lymphocyte ratio did not correlate with either infection or rejection (P greater than 0.05). In conclusion, an increase in the %TR+ lymphocytes indicates the presence of infection, especially acute infection, or, less likely, rejection in the cardiac transplant recipient, but its clinical utility may be as a screening test for the presence of infection, especially early infection in CTRs during the posttransplantation period. The CD4/CD8 lymphocyte ratio does not correlate with the presence of infection or rejection in the CTR.

Symptomatic abdominal aortic aneurysms in long-term survivors of cardiac transplantation.

Herein we report the only two long-term survivors of cardiac transplantation who underwent successful repair of symptomatic abdominal aortic aneurysms since the advent of cyclosporine therapy in 1983. Review of the world's literature indicates that the only two recorded cases of repair of symptomatic abdominal aortic aneurysms after cardiac transplantation occurred before the use of cyclosporine. The presentation and clinical course of our patients recently treated are presented, and perioperative care and immunosuppressive management are outlined. As the number of long-term survivors after cardiac transplantation increases, the incidence of other atherosclerotic complications including abdominal aortic aneurysm is likely to become more common, requiring extended cardiovascular follow-up.

Subnormal heart period variability in heart failure: effect of cardiac transplantation.

Heart period variability and arterial baroreceptor-cardiac reflex function were studied in cardiac transplant patients to determine if correction of heart failure restores parasympathetic control mechanisms toward normal. Heart period variability (standard deviation [SD] of 120 consecutive RR or PP intervals) was measured at supine rest in 34 patients with congestive heart failure (23 patients receiving diuretics, digoxin or vasodilators and 11 patients weaned from all medications), 30 cardiac transplant patients (both innervated recipient and denervated donor atrial rates) and 16 age-matched healthy control subjects. Arterial baroreflex gain was evaluated with intravenous bolus injections of phenylephrine in 22 transplant patients. Mean heart period variability (+/- SEM) was significantly lower (p less than 0.05) in the heart failure groups (22 +/- 3 ms for medicated and 17 +/- 3 ms for nonmedicated) than in the transplant patients (41 +/- 5 ms) or control subjects (58 +/- 5 ms). Heart period variability of the transplant patients was less than that of the control patients (p less than 0.05). A stepwise regression model revealed that heart period variability was inversely related to systolic arterial pressure and directly related to time after transplantation (R2 = 0.39; p = 0.03) in the transplant patients. Baroreflex gain of normotensive transplant patients was normal (11.7 +/- 1.0 ms/mm Hg) and correlated directly with heart period variability (r = 0.62; p less than 0.001). These data suggest that subnormal levels of cardiac parasympathetic activity at rest associated with congestive heart failure can be restored progressively toward normal by correction of congestive heart failure after cardiac transplantation. Post-transplant hypertension opposes this correction of baseline parasympathetic activity.

Pericardial repair of endocardial defect following regional endocardial resection for ventricular tachycardia.

Regional endocardial resection is the accepted surgical treatment for sustained monomorphic ventricular tachycardia. In patients requiring extensive endocardial resection, or with large aneurysms involving the interventricular septum, the resulting defect may result in weakened myocardium and, ultimately, ventricular septal defect or ventricular rupture. A new approach for repair of the resulting defect is proposed using an autogenous pericardial patch sutured to normal endocardium and included in the aneurysm repair. This technique was performed in six patients undergoing surgery for drug refractory ventricular tachycardia. All patients had large anterior left ventricular aneurysms with endocardial scar extending onto the septum. The large endocardial defect left after endocardial resection and aneurysmectomy was repaired with a pericardial patch. No intraoperative complications (e.g., suture line bleeding) were observed as a result of this technique. All patients are alive, and five of the six patients no longer have inducible ventricular tachycardia. An improvement in congestive heart failure symptoms at 1-9 months of follow-up was noted following surgery. We conclude that the pericardium can be safely used to cover endocardial defects resulting from regional endocardial resection for sustained ventricular tachycardia.

Effects of regional alpha- and beta-blockade on resting and hyperemic coronary blood flow in conscious, unstressed humans.

Our purpose was to determine if there are basal adrenergic influences on the coronary circulation in humans. We studied 56 patients with denervated hearts after cardiac transplantation and 19 normally innervated patients with angiographically normal coronary arteries. Coronary blood flow velocity was measured during cardiac catheterization with a subselective 3F intracoronary Doppler catheter. Heart rate was controlled by atrial pacing. Epicardial coronary artery diameter was measured by automated analysis of digital coronary angiograms. Coronary flow reserve was assessed by intracoronary papaverine hydrochloride (12 mg) injections. Regional sympathetic blockade was produced by intracoronary injections of phentolamine (3 mg, alpha) and propranolol (2 mg, beta) or metoprolol (3 mg, beta 1). After alpha-blockade, mean arterial pressure fell significantly (p less than 0.05) in both the denervated transplant (-5.8 +/- 1.5%) (mean +/- SEM) and normally innervated patients (-12.6 +/- 3.2%). Reductions in coronary flow velocity also were observed in these groups (-8.2 +/- 2.3% and -9.2 +/- 5.8%, respectively). Calculated coronary vascular resistance was unchanged. Similar changes were seen when patients were pretreated with beta-blockade before alpha-blockade. Nonspecific beta-blockade did not affect mean arterial pressure but decreased coronary velocity (innervated, -11.6 +/- 3.9%; denervated, -9.3 +/- 2.4%) and increased coronary vascular resistance (innervated, 15.4 +/- 6.7%; denervated, 10.2 +/- 3.7%). Coronary vascular resistance did not rise in either group after selective beta 1-blockade with metoprolol. Coronary flow reserve did not change in either patient group after either alpha- or beta-blockade. Changes in epicardial coronary artery diameter were small and generally not significant. These data suggest that alpha-receptor-mediated vascular tone is negligible in both denervated transplant patients and normally innervated patients. Additionally, the increase in vascular resistance after nonselective beta-blockade is the result of direct beta 2 vascular effects. Our data further suggest that there is little adrenergically mediated epicardial artery tone (either humoral or neural) at rest and that maximal vasodilator responses are not limited by adrenergically mediated vasomotor tone.

Orthotopic cardiac transplantation: evaluation with CT.

As cardiac transplantation has become widely available, computed tomography (CT) of the chest has played a useful role in the examination of patients after heart transplantation. To determine anatomic features related to the procedure, the authors evaluated 59 scans in 46 patients who had undergone orthotopic cardiac transplantation. Aortic anastomosis (seen in 98% of scans) and altered spacing between the great vessels (83%) proved to be the most common and most reliable findings. Other features including atrial anastomosis, high main pulmonary artery segment, remnant superior vena cava, and cardiac reorientation were also seen. Accurate interpretation of adenopathy, mediastinal abscess, and pericardial effusion will be enhanced in these patients through a better understanding of the cardiovascular-pericardial complex, which is afforded by CT.

Arterial baroreflex abnormalities in heart failure. Reversal after orthotopic cardiac transplantation.

Arterial baroreflex control of the heart and peripheral circulation is markedly impaired in humans and animals with congestive heart failure. After reversal of heart failure in animal models, arterial baroreflex control of heart rate remains impaired for up to 8 months. Cardiac transplantation restores normal ventricular function and completely reverses heart failure, but does it normalize arterial baroreflex control of heart rate in humans? We studied baroreflex sensitivity in 11 patients with severe heart failure, six normal control patients, and 23 patients at 2 weeks to 4 years after orthotopic cardiac transplantation. Baroreflex sensitivity was assessed with intravenous bolus injections of phenylephrine and is expressed as change in RR or PP interval (msec) per millimeters of mercury rise in systolic arterial pressure. Atrial rate of both donor (denervated) and recipient (innervated) atria were measured in the transplant group. Baroreflex sensitivity in patients with severe heart failure was 2.0 +/- 0.3 msec/mm Hg, but in patients after cardiac transplantation, it was 13.0 +/- 0.9 msec/mm Hg (p less than 0.001). The responses in the transplant group were similar to those observed in normal controls (10 +/- 1.2 msec/mm Hg, p = NS). Our data indicate that patients with severe congestive heart failure have marked abnormalities of baroreflex control, which are reversed as early as 2 weeks after cardiac transplantation. In view of this rapid reversal, we consider it unlikely that abnormal baroreflex sensitivity seen in heart failure is due to structural alterations in the baroreceptors. We speculate that neurohumoral rather than structural abnormalities account for depressed baroreflex sensitivity in heart failure.

Surgical management of heparin-associated thrombocytopenia. Strategies in the treatment of venous and arterial thromboembolism.

We report the vascular surgical strategies and results in 13 patients with heparin-associated thrombocytopenia and describe useful in vitro techniques for the evaluation of anticoagulant therapy. Thirteen of 40 patients with heparin-associated thrombocytopenia had 18 cardiovascular procedures done to save life or limb. Greenfield filters were placed in eight patients to prevent pulmonary embolism. Eight patients had 10 arterial procedures, with alternative anticoagulation that used dextran or warfarin in five cases. In three cases iloprost, a derivative of prostacyclin and a potent platelet inhibitor, was infused intraoperatively and heparin was given. Both the use of alternative anticoagulants and platelet suppression by iloprost were clinically effective strategies. The concurrent measurement of plasma levels of beta-thromboglobulin and fibrinopeptide A in two patients confirmed that both approaches can successfully prevent activation of platelets and plasma coagulation during arterial surgery. One operative death occurred; all vascular reconstructions remained patent at 3 to 6 months. In two patients who received heparin alone for arterial surgery, both procedures resulted in thrombosis and limb loss. When major venous thromboembolism is complicated by heparin-associated thrombocytopenia, insertion of a Greenfield vena cava filter should be considered if there is significant risk of pulmonary embolism. When necessary, arterial surgery is feasible in patients with heparin-associated thrombocytopenia if alternative anticoagulation or adequate suppression of platelet reactivity can be achieved.

Expression of transferrin receptors on lymphocytes: its correlation with T-helper/T-suppressor cytotoxic ratio and rejection in heart transplant recipients.

Forty-one heart transplant recipients were monitored serially for the expression of transferrin receptors and T-helper/T-suppressor cytotoxic ratios on circulating lymphocytes during the hospitalization periods after heart transplantations (60.5 +/- 18.9 days). These values were retrospectively correlated with the patients' clinical status with respect to rejection and infection. During clinically stable periods the average values of percentage of transferrin receptor-positive lymphocytes and T-helper/T-suppressor cytotoxic ratios were 5.9 +/- 4.3 and 1.5 +/- 1.0, respectively. The percentage of transferrin receptor-positive lymphocytes increased to a level of 12.0 +/- 5.4 (p less than 0.001) during the early prerejection phase and remained at this level throughout the rejection period. T-helper/T-suppressor cytotoxic ratios increased to 1.96 +/- 0.92 during the early prerejection phase (p less than 0.05), peaked at 2.30 +/- 1.21 during the late prerejection phase (p less than 0.01), but began to decline by the rejection period. After rejection treatment percentage of transferrin receptor-positive lymphocytes decreased to 8.4 +/- 5.3 (p less than 0.05), and T-helper/T-suppressor cytotoxic ratios decreased to normal levels. In contrast, in patients with infectious complications, a remarkably elevated percentage of transferrin receptor-positive lymphocytes (20.7 +/- 11.7) and relatively low T-helper/T-suppressor cytotoxic ratios (1.3 +/- 0.5) were noted. The data show an association between the clinical status, such as rejection and infection, and these immunologic measurements as transferrin receptor-positive lymphocytes and T-helper/T-suppressor cytotoxic ratios in heart transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiological observations during QRS alternans in a patient with incessant tachycardia.

Electrophysiological observations during preoperative and intraoperative study of a 46-year-old patient with incessant ventricular tachycardia and QRS alternans demonstrated a potential mechanism for this electrocardiographic finding. During QRS alternans, conduction delay (or block) was recorded from the site of origin of the tachycardia, high on the anterior septum to the His bundle: After procainamide infusion, the tachycardias slowed and, concurrent with the disappearance of QRS alternans, conduction from the site of tachycardia origin to the His bundle could no longer be demonstrated.

Clinical significance of pericardial effusion after heart transplantation.

Fifty-two consecutive patients who underwent orthotopic heart transplantation at our institution were evaluated by two-dimensional (2D) echocardiography at frequent intervals for 12 weeks after transplantation and at three monthly intervals for 1 year. Thirty-eight of 52 patients had adequate 2D echocardiograms and comprised the retrospective study group. Pericardial effusion was documented in 15 of 38 patients (40%). Pericardial effusion was moderate in two (5%) and small in seven patients (18%). Large pericardial effusion was demonstrated in six of 38 patients (16%). Three of 38 patients (8%) developed cardiac tamponade manifested by hypotension in the presence of a large pericardial effusion. The diagnosis of cardiac tamponade was aided by 2D echocardiography leading to prompt pericardiocentesis. The presence of pericardial effusion in patients after their transplantation did not demonstrate independent correlation with chest tube output after operation, cyclosporine therapy, acute rejection, level of blood urea nitrogen (BUN), infection or preoperative diagnosis of idiopathic dilated cardiomyopathy. The presence of cyclosporine therapy, acute rejection, and a preoperative diagnosis of idiopathic dilated cardiomyopathy, however, yielded an 86% probability of having pericardial effusion. Follow-up 2D echocardiograms obtained 301 +/- 106 days after transplantation were available in 25 patients. Fifteen patients (60%) had no pericardial effusion present on either the initial or follow-up 2D echocardiogram. The majority of cases of the pericardial effusion present on initial or follow-up echocardiograms were resolving on the follow-up study.(ABSTRACT TRUNCATED AT 250 WORDS)