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.

Results of a prospective multicenter study on port-access coronary bypass grafting.

BACKGROUND: We reviewed the initial patient series of three institutions performing large volume port-access (PA) coronary artery bypass grafting (CABG) to evaluate the efficacy of this new procedure. METHODS: From October 1996 until June 1998, 302 consecutive patients underwent isolated CABG using the PA approach. Patients (mean age 60.7 years) were predominantly male (77.5%) and received a mean of 2.3 distal anastomoses; few were New York Heart Association class III or IV (15.9%). The distribution of the number of grafts was: 76 (25.2%) single, 110 (36.4%) double, 73 (24.2%) triple, and 43 (14.2%) four or more bypass grafts. The Society of Thoracic Surgeons (STS) Database data collection form was used prospectively by all three institutions to define patient risk factors and record outcomes. RESULTS: Total 30-day hospital mortality was 0.99% compared to the STS-database-model-predicted risk of 1.2%. Complication rates for the PA CABG patients compared with risk-matched morbidity rates from the STS data for CABG alone were: reoperation for bleeding, 3.3% versus 1.9%; ventilatory support more than 1 day, 1.7% versus 3.8%; stroke, 1.7% versus 1.2%; and perioperative transmural myocardial infarction 0% versus 1.3%. CONCLUSIONS: The STS CABG risk-adjusted model demonstrates that the 30-day mortality for patients undergoing PA CABG is lower than predicted for traditional CABG patients (confidence intervals not available). Likewise, the morbidity was low, with minimal ventilatory support, pulmonary complications, and atrial fibrillation. The port-access technique is an acceptable strategy for multivessel bypass grafting.

Outcomes analysis in cardiac surgery.

Outcomes research is a quantitative assessment of the results of care. Outcomes analysis provides information that benefits the physician, the patient, the institution and the health care purchasers. It provides relevant and timely information for the assessment of the heart centre's performance. Outcomes data have proven to be useful to the attending physicians by providing a basis for clinical decision making. Patients may be appraised of the usual results and the risks of various treatment strategies and make informed decisions on their care. The purchasers of health care will be better informed regarding the costs and effectiveness of the care being delivered. O'Connor et al. have stated that methods of improving care are often discussed but are difficult to achieve due to processes of care being hidden from view. Outcomes research is a comprehensive performance evaluation strategy that may be used to discover the impact of these hidden aspects of care. This technology of the patient's experience is bringing cardiac surgery to a new level of excellence.

Urinary thromboxane B2 in cardiac transplant patients as a screening method of rejection.

Noninvasive methods for regular monitoring of cardiac transplant patients for acute rejection are preferable to the only currently accepted method involving frequent endomyocardial biopsies. Thromboxane A2 (TXA2) is synthesized in large amounts by monocytes/macrophages during organ graft rejection. It enhances T-lymphocyte clonal expansion and cytotoxic function as well as upregulating the major histocompatibility class II expression on antigen presenting cells. Experimentally increased urinary excretion of TXA2 metabolites is associated with cardiac transplant rejection. We therefore compared urinary immunoreactive thromboxane B2 (i-TXB2) levels to the rejection score of the endomyocardial biopsies. In addition we graded the degree of activated lymphocytes in peripheral blood. Urinary i-TXB2 was significantly higher in patients exhibiting medium to severe rejection than in patients without rejection (1236 +/- 372 vs. 526 +/- 57 pg/mL). The urine i-TXB2 (704 +/- 48 pg/mL) of all patients who participated in this study, whose endomyocardial biopsy indicated rejection, was also significantly higher than in the non-rejecting group. Increased levels of urine i-TXB2 were associated with increased biopsy scores. Circulating activated lymphocytes was also significantly increased in patients with moderate/severe rejection compared to patients with no rejection (66 +/- 11 vs. 39 +/- 4 per mm (3)) (p < 0.01). Further, this study shows that urine i-TXB2 is associated with increased endomyocardial biopsy scores (acute rejection scores) and blood lymphocyte activation. Thus we conclude that urine i-TXB2 may be of potential value as a diagnostic screening test for helping identify cardiac transplant patients undergoing acute rejection.

Cardiac assist devices.

The two primary goals of mechanical circulatory support are to provide adequate perfusion of the vital organs and to decrease cardiac work. The support of the myocardium is in an effort to cause a reversal of cardiac damage. The recovery process apparently takes place in two stages. Initially, there is a rapid functional recovery of cells in marginally ischemia areas. Then there is a slower process of hypertrophy of normal and recovering myofibers. The process involves the reversal of interstitial and of intercellular myocardial edema in areas of viable myocardium while halting the extension of necrosis into reversibly ischemic areas. It appears that this process is extended from 3 to 5 days, and functional recovery can occur for up to 2 weeks. After a 2-week period, there appears to be little functional recovery of myocardial cells. In autopsy series of nonsurvivors, it appears that most of the patients had suffered from biventricular failure. Biventricular failure appears to be one of the more common complications of the support patient. Right ventricular failure will be attempted to be supported by right ventricular assist devices. The right ventricular assist device, unfortunately, adds a level of complication to the recovery process for the bridge-to-transplant or cardiomyopathy patient. The patients who are involved in support fall into three categories: (1) the bridge-to-transplant patient, (2) the patient recovering from postcardiotomy, and (3) the patient who recovers from an acute myocardial insult. It appears that after 2 weeks the recovery period for all of these groups demonstrates no further functional recovery. The bridge-to-transplant patients usually need to be supported until the transplant occurs. The postcardiotomy patient and the acute myocardial failure patient are the most disappointing support group, since they have a higher morbidity and mortality, and a lower chance of recovery. Salvage rates appear to be in approximately the 25% range in the acute insult category.

Pediatric cardiopulmonary bypass: a review of current practice.

Devices and techniques used for pediatric cardiopulmonary bypass are ever changing. There are frequently reports in the literature about new techniques and new devices. Periodic surveys are helpful because they reveal the actual extent to which these techniques and devices are applied to clinical practice. Advances in research are bringing about a better understanding of the intricate aspects of CPB and the effects of CPB on pediatric patients. There appears to be a trend from widely divergent approaches to CPB for pediatric patients to more uniformity in practice. For example, the use of membrane oxygenation and arterial line filtration has become universal, and there is an increase in the use of all types of safety devices. Techniques reported in the medical literature at the beginning of the decade, such as, the use of modified ultrafiltration, the use of centrifugal cell washers to process packed red blood cells before adding them to the prime, and the use of the antifibrinolytic drug, aprotinin, have become part of practice at a large number of pediatric heart centers. Periodic surveys are useful, as they provide a measurement of current practice. They also provide a historical record of the advances in the field.

Paediatric perfusion practice in North America: an update.

In August 1994, an updated survey questionnaire was mailed to each paediatric open-heart surgery programme in North America as a follow-up to the 1989 paediatric survey. The survey requested demographic data, equipment selection criteria and specific perfusion techniques for paediatric patients. The earlier survey revealed a wide range of clinical practice. Data from the recent survey were compared with the 1989 survey to identify current programme demographics and trends in equipment use and techniques. Responses were received from 125 hospitals (110 active programmes and 15 programmes that do not perform paediatric open-heart surgery) for a response rate of 74%. Of the 110 active centres, 77 perform both adult and paediatric cardiac surgery, and 33 perform paediatric surgery exclusively. Forty-three centres reported that they perform paediatric cardiac transplantation, an increase from 35 centres in 1989. Total caseload increased by more than 8% per year from 1988 to 1994. In 1994, 18% of the patients were operated upon during the first month of life (versus 15% in 1989), and 46% were operated on during the first year of life (versus 45% in 1989). While the 1989 survey was characterized by a high degree of heterogeneity in equipment and techniques, the recent survey reveals a trend toward homogeneity among respondents. The use of membrane oxygenation and arterial line filtration has become universal, and there was an increase in the use of all types of safety devices in the cardiopulmonary bypass circuit.

Artificial circulatory support with textured interior surfaces. A counterintuitive approach to minimizing thromboembolism.

BACKGROUND: Although numerous left ventricular assist devices (LVADs) have been used clinically, frequent thromboembolic complications have been reported despite the smooth interior LVAD surfaces and systemic anticoagulant medication. In contrast, the Thermo Cardiosystems HeartMate 1000 IP LVAD has textured interior surfaces that are promptly covered by a densely adherent neointima. We hypothesize that elimination of a direct interface between prosthetic material and blood elements reduces the risk of peripheral embolization and minimizes the necessity for systemic anticoagulant medication. This report defines the thromboembolic risk of this type of LVAD and characterizes the nature and effectiveness of the various anticoagulation regimens that were tested during the initial clinical trial with this device. METHODS AND RESULTS: All values are reported as mean +/- SD. Fifty-four males and three females with an average age of 47 +/- 11 years were supported with the HeartMate 1000 IP LVAD for an average of 62 +/- 76 days at 11 clinical centers in the United States. Patients were prospectively evaluated for thromboembolic complications. Five different anticoagulation regimens were used during the first 4 postoperative weeks: no anticoagulants, low-molecular-weight dextran, heparin, dipyridamole plus aspirin, or miscellaneous agents. After the first 4 weeks, the patients were treated with aspirin plus dipyridamole or miscellaneous agents. Prothrombin time (PT), partial thromboplastin time (PTT), and fibrinogen values for the patients were measured at 0.1, 1, 2, 4, 8, 12, 16, 20, 24, 32, and 46 weeks during support. Two patients (3.5%) suffered thromboembolic cerebrovascular complications, an incidence of 0.2 episodes per patient-year of observation. One episode was due to fungal vegetation developing on the device and the other was due to embolization from a previously placed native mechanical aortic valve prosthesis. In the absence of infection, there were no device-related thromboembolic complications. Mean prothrombin time for all groups was 13.3 +/- 0.5 seconds with no significant intergroup differences. Mean partial thromboplastin time during the first 4 weeks for the heparin-treated group was 53.3 +/- 6.6 seconds, which was significantly longer than for all other groups, but fell to control values after heparin was discontinued at 4 weeks. Mean fibrinogen level for all groups was 370 +/- 48 mg/dL, with no intergroup differences. CONCLUSIONS: The HeartMate 1000 IP LVAD provides adequate circulatory support with a low risk of thromboembolism despite minimal systemic anticoagulation. The use of textured surfaces may be an important factor contributing to the low observed risk of thromboembolic complications.

Alternative method of ultrafiltration after cardiopulmonary bypass.

A revised circuit design for modified ultrafiltration is presented rendering the technique more convenient for use after cardiopulmonary bypass when blood cardioplegia is used. The procedure employs a hollow-fiber ultrafiltration device attached to the cardioplegia circuit. A bubble trap, heat exchanger, and a pressure monitor are incorporated as safety features. The technique has been used in 80 patients (30 pediatric and 50 adult) and has been associated with relevant increases in colloid osmotic pressure and hematocrit.

A reliable bridge to cardiac transplantation: the TCI left ventricular assist device.

The Thermo Cardiosystems (TCI) HeartMate, a pneumatically driven, implantable left ventricular assist device, was designed for long-term support of the failing heart. Between February 1990 and August 1992, the HeartMate was implanted in 11 heart transplant candidates because of profound deterioration of left ventricular function. Patients had a mean cardiac index of 1.6 L.min-1 x m-2 and a mean pulmonary capillary wedge pressure of 33 mm Hg despite maximal pharmacologic support with at least three inotropic medications. In addition, 5 patients were being supported with an intraaortic balloon pump. Nine patients were bridged successfully to cardiac transplantation. The mean cardiac index after implantation of the left ventricular assist device was 3.2 L.min-1 x m-2. Support ranged from 2 to 143 days (mean duration, 60 days). One patient died early of low output secondary to right heart failure, and a second died of air embolism, which occurred intraoperatively. All surviving patients became fully ambulatory. There were no thromboembolic complications during a total of 658 patient-days of support on a regimen of only 80 mg of aspirin daily. The 9 bridged patients are currently alive 4 to 34 months after transplantation. The TCI HeartMate provides safe and effective hemodynamic support with low risk of complications and virtual freedom from thromboembolism on a regimen of minimal anticoagulation.

Multicenter clinical evaluation of the HeartMate 1000 IP left ventricular assist device.

The Thermo Cardiosystems Inc (Woburn, MA) HeartMate 1000 IP left ventricular assist device (LVAD) has been evaluated as a bridge to transplantation in 34 patients for up to 324 days at seven clinical centers in the United States. Sixty-five percent of the patients underwent transplantation, 80% of whom were discharged from the hospital. Six additional control patients, transplant candidates who met the entrance criteria but who did not receive the device, were also included in the study. Although 3 (50%) of the control patients received transplants, all 6 died within 77 days of having met the LVAD inclusion criteria (100% mortality). Complications resulting from use of the device were comparable with those previously reported for all ventricular assist devices, except for thromboembolic events: bleeding, 39%; infection, 25%; and right heart failure, 21%. No device-related thromboembolic events occurred, although 1 patient experienced an event related to a mechanical aortic valve in the native heart. None of the complications had a significant negative association with outcome of the patient except for right heart failure. All survivors had a significant improvement in hepatic function before transplantation. Total bilirubin values were reduced by 60% during LVAD support. No significant differences were observed when total bilirubin values were compared at 30 and 60 days after LVAD support and at 30 and 60 days after transplantation in a cohort of 15 patients (p greater than 0.05). The improvement in renal function was less predictable than that of hepatic function. Creatinine values decreased significantly before transplantation; however, the values measured at 30 and 60 days after transplantation were higher than those measured at the same intervals after LVAD support had been initiated, and this increase is presumably related to the immunosuppressive drugs. In conclusion, the HeartMate 1000 IP LVAD has been shown to be effective in supporting end-stage cardiomyopathy patients to transplantation. Thromboembolism, previously regarded as a serious complication with such devices, has not been a problem with this device. Additional patients are being enrolled into the study to further document the safety and effectiveness of this technology.

Surgical complications in bridging to transplantation: the Thermo Cardiosystems LVAD.

Left ventricular assistance with a number of different devices has been used to successfully bridge patients to cardiac transplantation. Surgical complications or complications related to the device itself, however, may preclude transplantation or lead to death. We report our recent experience with the Thermo Cardiosystems model 14 "HeartMate" left ventricular assist device in 3 patients. The device was implanted for 15 to 95 days. Complications included mediastinitis and peritonitis associated with the device in place before transplantation, and colonic perforation, and a late diaphragmatic hernia after transplantation. Despite these and other minor complications, all 3 patients underwent successful cardiac transplantation. Mechanical support for the right ventricle was not necessary. The Thermo Cardiosystems left ventricular assist device provided excellent support in a range of physiological conditions with no mechanical malfunction despite the surgical complications.

Mediastinitis complicating successful mechanical bridge to heart transplantation.

A 22-year-old man with severe end-stage cardiomyopathy required placement of a left ventricular assist device. Purulent mediastinitis and peritonitis developed while the device was in place. The patient survived a prolonged course of treatment, with mediastinal and peritoneal irrigation and parenteral antibiotics, before undergoing a successful heart transplantation 12 weeks after placement of the left ventricular assist device.

Celiac artery aneurysms: case reports.

Two recent patients with celiac artery aneurysms focus attention on the relevant diagnosis and therapeutic alternatives that lead to a successful outcome in these patients. Awareness of the nonspecific symptoms associated with splanchnic arterial aneurysms combined with ultrasonography, computerized axial tomography, and arteriography lead to the appropriate diagnosis of a celiac artery aneurysm prior to rupture and exsanguinating hemorrhage. Aneurysm resection offers a definitive means of treatment. Selective use of revascularization techniques bolsters the surgical approach by preventing hepatic ischemia and serving as an additional source of visceral arterial blood flow. Our use of an autogenous or prosthetic graft from the intrarenal abdominal aorta proved to be a helpful adjunctive technique. Long-term vigilance is important because of the association of celiac artery aneurysms with other arterial occlusive and aneurysmal disease.

Traumatic rupture of the interventricular septum and tricuspid valve: case report.

Cardiac injury following blunt trauma is an important cause of morbidity and mortality and is often unsuspected. Isolated chamber rupture and valvular injury are infrequent but recognized consequences of nonpenetrating trauma. This report describes a patient who developed a perimembranous ventricular septal defect and disruption of the septal leaflet of the tricuspid valve as a consequence of blunt trauma. Diagnosis and management of traumatic ventricular septal rupture are discussed.

Coronary artery bypass surgery: emerging trends in mortality.

In a consecutive series of 4,697 patients undergoing coronary artery bypass surgery, these risk factors were found to be significant for increased postoperative mortality: age greater than 70, female sex, unstable angina, prior myocardial infarction, hypertension, diabetes mellitus, and ejection fraction less than .40. A comparison by year (1980-1988) revealed a steadily increasing incidence of these risk factors. Future analysis of coronary artery bypass mortality should include risk-factor stratification.

Cardiac transplantation in a regional center: goals and results at two years.

Cardiac transplantation moved from the realm of an investigational procedure to a therapeutic modality in the early 1980s. While one-year survival of 80 percent or greater can be expected, close follow-up is required to monitor for rejection, infection, and other late complications. With the need for close surveillance, both short and long-term, improved patient access to the transplantation center based on geographic proximity allows enhanced care by the original transplant team.