Aortic valve replacement or heart transplantation in patients with aortic stenosis and severe left ventricular dysfunction.

INTRODUCTION: The decision to perform aortic valve replacement (AVR) or heart transplantation (HTx) for aortic stenosis (AS) with severe left ventricular dysfunction is difficult and may be affected by prior myocardial infarction (MI) and coronary artery disease (CAD). METHODS: Patients who underwent AVR from 1988 to 2001 with left ventricular ejection fraction (LVEF) <30% and severe AS (aortic valve area [AVA] < 1.0 cm(2); n = 51) were assessed for operative mortality, late survival, and predictors of outcome, and were compared with HTx. Subsequently, 131 patients with LVEF ≤ 35% who underwent AVR for critical AS (AVA < 0.8 cm(2)) were evaluated. RESULTS: In the first 51 patients, 3-year survival was 100% ± 0% with no CAD, and 45% ± 10% with CAD (P < .05); 3-year survival was 88% ± 12% with no bypass, 73% ± 12% with one to two grafts, and 18% ± 11% with three grafts (P < .01). Survival with HTx was 78% at 3 years. In the subsequent analysis of 131 patients, 90-day survivors were followed for a mean 4.6 ± 3.5 years. Advanced age (P = .001) was the only predictor of long-term mortality. LVEF improved from 28.5% ± 5.2% before AVR to 45.4% ± 13.2% at 1-month postoperatively (P < .0001). New York Heart Association (NYHA) class III/IV decreased from 94.2% pre-AVR to 12.8% at 1 year (P < .0001). Predictors of LVEF recovery were no previous MI (P = .007) and higher AS gradient (P = .03). CONCLUSIONS: In severe AS and LVEF <30% with no concomitant CAD or with CAD requiring one to two bypass grafts, AVR has a survival equal to or exceeding that of HTx. In patients with CAD requiring more than two bypass grafts, survival is significantly reduced, and HTx can be considered.

Exercise performance comparison of bicaval and biatrial orthotopic heart transplant recipients.

BACKGROUND: The standard biatrial technique for orthotopic heart transplantation uses a large atrial anastomosis to connect the donor and recipient atria. A modified technique involves bicaval and pulmonary venous anastomoses and is believed to preserve the anatomic configuration and physiological function of the atria. Bicaval heart transplantation reduces postoperative valvular regurgitation and is associated with a lower incidence of pacemaker insertion. OBJECTIVE: The aim of this study was to compare postoperative functional capacity and exercise performance in patients with bicaval and biatrial orthotopic heart transplantation. METHODS: Patients were selected for the study if they did not have any of the following: obstructive coronary artery disease (>50% stenosis), severe mitral or tricuspid regurgitation, signs of rejection (grade≥1B-1R) on endomyocardial biopsy during the prior year, respiratory impairment, a permanent pacemaker, orthopedic or muscular impediments, or lived more than 150 miles from the medical center. A total of 27 patients qualified. In 15 patients who received a biatrial heart transplant and 12 patients with a bicaval heart transplant, a stationary bicycle exercise test was performed. Ventilatory gas exchange and maximum oxygen consumption measurements were measured. RESULTS: Recipient and donor characteristics, including body surface area, donor/recipient weight mismatch, immunosuppressive regimen, and self-reported weekly exercise activity, did not differ between the biatrial and bicaval groups (P=not significant [NS]). At peak exercise, similar heart rate, workload, oxygen consumption, carbon dioxide production, ventilation, functional capacity, and exercise duration were found between the 2 groups (P=NS). Patients in the biatrial group were studied later than patients in the bicaval group (6.54±0.71 vs 4.68±0.28 years; P<.001). CONCLUSION: There were no significant differences in the exercise capacity between patients with biatrial versus bicaval techniques for orthotopic heart transplantation. Factors other than the atrial connection (such as cardiac denervation, immunosuppressive drug effect, or physical deconditioning) may be more important determinants of subnormal exercise capacity after heart transplantation. Nevertheless, the reduction in morbidity and postoperative complications and the simplicity in the bicaval technique suggest that bicaval heart transplantation offers advantages when compared with the standard biatrial technique.

Prolonged cold ischemic times and less donor-recipient histocompatibility accelerate graft vascular disease.

INTRODUCTION: The long-term success of cardiac transplantation is limited by graft atherosclerosis, also known as graft vascular disease (GVD). GVD is currently the leading cause of late allograft failure in cardiac transplant recipients. The aim of this study was to assess the effects of cold ischemic preservation time (CIPT) and degree of donor-recipient histocompatibility on GVD using a rat heterotopic cardiac transplantation model. METHODS: ACI-Lewis (n=9), Lewis-F344 (n=9), and Lewis-Lewis (n=9) donor-recipient rat strain combinations were subjected to variable durations of CIPT (0, 4, and 24 hours in University of Wisconsin solution at 4°C) prior to transplantation (n=81 total). The ACI-Lewis allografts differed in both major histocompatibility complex (MHC) class I and II antigens, the Lewis-F344 allograft combination differed in multiple non-MHC antigens, and the Lewis-Lewis isograft combination was syngeneic. Grafts were harvested at 90 days. Intimal area ratio (IAR), intimal thickness score (ITS), and rejection score (RS) were determined for each specimen. RESULTS: The Lewis-Lewis transplant group had a significantly higher mean RS (P=.036) with 24 hours than with 0 hours of CIPT in this rat heterotopic transplantation model at 90 days. The Lewis-F344 group had a significantly higher IAR (P=.035), ITS (P=.030), and RS (P=.017) with 24 hours than with 0 hours of CIPT. The ACI-Lewis group had high levels of GVD with all durations of CIPT (0, 4, and 24 hours); as a consequence, there were no significant differences in the ITS, IAR, or RS. With 0 hours of CIPT, the ACI-Lewis transplantation group yielded a significantly higher mean IAR (P=.029), ITS (P=.003), and RS (P=5.02×10(-5)) than the Lewis-Lewis group. The Lewis-F344 group had a significantly higher mean RS (P=.003) than the Lewis-Lewis (syngeneic) group. The ACI-Lewis transplantation group had a significantly higher mean IAR (P=.035), and trended toward a higher ITS (P=.058) than the Lewis-F344 group. CONCLUSION: Longer cold ischemic preservation time and less donor-recipient histocompatibility were associated with more advanced GVD in a rat heterotopic transplantation model, especially when there were multiple MHC mismatches as in ACI-Lewis allografts, but also occurred when there were differences in multiple non-MHC antigens as in the Lewis-F344 allografts. There was a lesser effect of longer cold ischemic time on GVD in the Lewis-Lewis syngeneic (isograft) group, suggesting that greater histocompatibility can mitigate the adverse effects of longer ischemic times.

Treating stroke as a medical emergency: a survey of resident physicians' attitudes toward "brain attack" and carotid endarterectomy.

OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment of acute stroke. Critical to this goal is the education of physicians during their residency training. METHODS: Resident physicians in Los Angeles who were in family practice (18%), internal medicine (51%), emergency medicine (20%), and neurology (11%) and had already completed their first year of training responded to a questionnaire on stroke and the treatment of carotid stenosis. RESULTS: Of the 266 respondents, 76% had heard of the "brain attack" campaign, 22% did not identify dysarthria as a symptom of stroke, and 21% did not identify obtundation as a presentation of stroke. Twenty-eight percent chose not to use tissue plasminogen activator for acute ischemic stroke, and 60% recognized the need to begin treatment within 3 hours. More than 90% of respondents were able to identify correct screening tests for patients with suspected carotid stenosis. However, 56% responded that they would not advocate operating on patients with asymptomatic severe stenosis (>70%) until stenosis reached a critical value (85%). Conversely, 45% would recommend operative treatment for symptomatic patients who had less than 60% stenosis. Sixty-eight percent would refer patients to vascular surgeons, 14% to neurosurgeons, and 17% to both for carotid endarterectomy. CONCLUSION: Recognition of stroke as a medical emergency is improving. However, significant progress can still be made in the recognition of stroke symptoms. Primary care and neurology residents remain skeptical about carotid endarterectomy for asymptomatic patients, whereas there is enthusiasm for treating stroke survivors. Education by members of the surgical community could promote the aggressive treatment of asymptomatic patients to prevent stroke.