Staphylococcus capitis endocarditis due to a transvenous endocardial pacemaker infection: case report and review of Staphylococcus capitis endocarditis.

OBJECTIVES: Newer microbiologic methods to determine the species of coagulase-negative staphylococci (CoNS) have evolved which have shown that most endocarditis due to CoNS is caused by Staphylococcus epidermidis, and far fewer by Staphylococcus warneri and Staphylococcus lugdunensis. METHODS: The recent opportunity to successfully treat a patient with methicillin-resistant Staphylococcus capitis endocarditis secondary to an infected transvenous pacemaker led to a review of the literature relating to S. capitis endocarditis. RESULTS: Thirteen previously recorded patients were identified. Twelve (86%) patients were male. Ten had endocarditis associated with a native valve, two with prosthetic valves and one with a transvenous pacemaker. Mortality was low in all 14 cases (including this case report) with only two deaths; one in a patient with a native valve and the other with a prosthetic valve. Four of the isolates were methicillin resistant but sensitive to vancomycin, which was used in the treatment of eight patients. Those patients with prosthetic cardiac devices appear to do better when the devices are surgically removed. CONCLUSIONS: CoNS as a cause of endocarditis appears to be increasing and the current ability to determine the species of these organisms should elicit the epidemiology, clinical characteristics and biomolecular mechanisms involved in the induction of valvular disease.

Aerosol cyclosporine prevents acute allograft rejection in experimental lung transplantation.

BACKGROUND: The incidence of acute rejection and the morbidity of systemic cyclosporine (INN: cyclosporine) after lung transplantation is significant. Experimental evidence suggests that the allograft locally modulates the immune mechanisms of acute rejection. The purpose of this study was to determine whether aerosolized cyclosporine would prevent acute cellular rejection, achieve effective graft concentrations with low systemic drug delivery, and locally affect production of the inflammatory cytokines involved in acute rejection. METHODS: Unilateral orthotopic left lung transplantation was performed in 64 rats (ACI to Lewis), which were divided into eight groups (each group, n = 8): group A, no treatment; groups B to D, aerosol cyclosporine 1 to 3 mg/kg per day, respectively; group E to H, systemic cyclosporine 2, 5, 10, and 15 mg/kg per day, respectively. After the animals were killed on postoperative day 2, 4, or 6, the transplanted lung, native lung, spleen, and blood were collected. Histologic studies, high-pressure liquid chromatography for trough cyclosporine concentrations, and reverse-transcriptase polymerase chain reaction for cytokine gene expression were performed. RESULTS: Untreated animals showed grade 4 rejection by postoperative day 6. Aerosol cyclosporine prevented acute rejection in a dose-dependent fashion, with group D animals (3 mg/kg per day) showing minimal grade 1 changes. Among animals receiving systemic cyclosporine, only group H (15 mg/kg per day) controlled (grade 1) rejection. However, aerosol cyclosporine, at an 80% lower dose, achieved significantly lower concentrations of cyclosporine in the graft (12,349 vs 28,714 ng/mg, p = 0.002004) and blood (725 vs 3306 ng/ml, p = 0.000378). Group F (systemic 5 mg/kg per day) had higher cyclosporine concentrations in the blood than group D (p = 0.004572) and similar tissue concentrations (p = 0.115180), yet had grade 2 rejection. Reverse-transcriptase polymerase chain reaction demonstrated equivalent suppression of inducible nitric oxide synthase but a 20- to 25-fold higher expression of interleukin-6, interleukin-10, and interferon-gamma in group D versus group H recipient allografts. CONCLUSION: Local delivery of cyclosporine by aerosol inhalation dose-dependently prevented acute pulmonary allograft rejection. Effective graft levels and low systemic drug delivery required significantly lower doses than systemic therapy alone. The gene expression of proinflammatory cytokines involved in allograft rejection was suppressed by aerosol cyclosporine therapy.

In the lung aerosol cyclosporine provides a regional concentration advantage over intramuscular cyclosporine.

BACKGROUND: Acute rejection remains an almost universal complication among lung transplant recipients. Refractory rejection as well as chronic systemic immunosuppression is associated with significant morbidity and mortality. Recent studies suggest that aerosol cyclosporine may address these issues by effectively preventing acute cellular rejection while maintaining low systemic drug concentrations. This study was designed to evaluate the concentrations of cyclosporine in blood and lung tissue after aerosol and intramuscular administration. METHODS: Lewis rats were divided into 4 experimental groups: Groups A (n = 33) and B (n = 30) received aerosol cyclosporine 3 and 5 mg/kg, respectively; Groups C (n = 33) and D (n = 30) received systemic cyclosporine 5 and 15 mg/kg, respectively. We used high-performance liquid chromatography to quantitate blood and lung tissue cyclosporine levels at timed intervals. We used the trapezoidal rule to approximate area under the concentration vs time curve (AUC). RESULTS: Aerosol delivery of cyclosporine resulted in higher and more rapid peak drug levels in lung tissue samples than did systemic delivery. At an equivalent 5 mg/kg dose, the cyclosporine AUC was 3 times higher with aerosol delivery than with intramuscular delivery in lung tissue (477,965 vs 157,706 ng x hour/g, respectively). The lung tissue: blood AUC ratio was highest in the aerosol groups (27.3:1 and 17.4:1) compared with the intramuscular groups (8.1:1 and 9.4:1). CONCLUSION: Local aerosol inhalation delivery of cyclosporine provides a regional advantage over systemic intramuscular therapy by providing higher peak concentrations and greater lung tissue exposure.

Congenital Heart Surgery Nomenclature and Database Project: mitral valve disease.

The extant nomenclature for mitral valve disease is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Mitral valve disease has been subdivided into stenotic and regurgitant lesions. Lesions have been characterized further by etiology and by anatomic location: supravalvar, valvar, and subvalvar. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Cardiac operations in solid-organ transplant recipients.

BACKGROUND: The success of solid organ transplantation has resulted in an increasing pool of patients that subsequently require cardiac surgical procedures, yet the perioperative management of these patients is not well documented. We report a single institutional experience with the management techniques used and the outcomes of the cardiac surgical procedures performed in solid organ transplant recipients with functioning allografts. METHODS: Sixty-four patients underwent 66 cardiac procedures broken down as follows: coronary artery bypass grafting, 30; single or combined valve replacement-repair, 24; combined coronary artery bypass grafting and valve repair, 3; aortic repair, 4; pericardiectomy, 3; transmyocardial laser revascularization, 1; and native cardiectomy, 1. Patients consisted of 40 kidney, 16 liver, 5 heart, 2 lung, and 1 liver and kidney transplant recipients. The mean interval from the time of transplantation to the cardiac operation was 53 months (range, 1 day to 220 months). Forty-six male and 18 female patients in New York Heart Association functional class III or IV had a mean age of 53 years (range, 19 to 77 years); 50% (32/64) were diabetic, and 97% (62/64) were hypertensive. Immunosuppressive therapy, cardiopulmonary bypass, and medical management were similar in all patients. RESULTS: There were two (3%) perioperative deaths, one of which was caused by an arrhythmia-induced cardiac arrest, and there were seven (11%) late deaths from non-cardiac-related causes. Major complications included 12 infections (19%), ten mediastinal reexplorations for the control of bleeding (16%), and nine others (15%). Sixteen of the 64 (25%) transplant recipients had chronic renal failure (serum creatinine levels, > 3 mg/dL), including 13 of 40 (33%) kidney transplant patients. Acute renal failure developed postoperatively in 7 (54%) of these 13 patients; the grafts failed permanently in 3 (23%). Three patients (5%), 2 kidney transplant recipients and 1 lung transplant recipient, experienced transient acute rejection. Fifty of the 55 surviving patients are alive and well (New York Heart Association functional class I or II) without recurrent cardiac disease at a mean follow-up period of 22 months. CONCLUSIONS: Although the short-term morbidity was significant, the low mortality and low incidence of permanent graft dysfunction indicate that solid organ transplant recipients can safely and effectively undergo subsequent cardiac surgical procedures.

Reoperative pulmonary thromboendarterectomy.

BACKGROUND: Recurrent symptomatic pulmonary hypertension is uncommon after primary pulmonary thromboendarterectomy (PTE). We reviewed our experience with patients undergoing repeat PTE to determine the risk factors for recurrent disease, and the selection criteria, relative risks, and functional outcomes of reoperative PTE. METHODS: Since 1990, 13 of 870 (1.5%) patients underwent reoperative PTE at our institution. These 7 men and 6 women (mean age 38.6 years) were contrasted with the most recent 225 patients (111 men, 114 women, mean age 52.7 years) who underwent primary PTE for whom complete hemodynamic data are available. The preoperative evaluation of all patients was similar. Pulmonary hemodynamic data and outcome measures were compared between groups. RESULTS: Of 13 reoperated patients: 69% (9/13) had their primary operation at another institution, 54% (7/13) initially underwent unilateral PTE, 38% (5/13) had identifiable coagulation disorders, 38% (5/13) had ineffective caval filtration, 31% (4/13) had suboptimal anticoagulation management, and 31% (4/13) had complete unilateral pulmonary artery obstruction. The mean interval to reoperation was 5.2 years (range 0.7 to 10.9 years). All control patients underwent bilateral PTE using hypothermic circulatory arrest. Operative mortality was 7.7% (1/13) with reoperation vs 8.4% (19/225) in controls. No difference (p = NS) was observed between groups in the preoperative pulmonary artery pressure (PAP) or pulmonary vascular resistance; however, the control group had a significantly (p < 0.05) greater reduction in the postoperative PAP (46/19, mean 28 mm Hg vs 59/23, mean 35 mm Hg) and PVR (271 +/- 172 vs 399 +/- 154 dynes/s/cm(-5)) compared with the redo group. No substantial difference in morbidity or functional outcomes was observed between groups. CONCLUSIONS: Reoperative PTE can be performed with a perioperative risk comparable with primary PTE, although the improvement in pulmonary hemodynamics is not as favorable. Bilateral primary operation, effective caval filtration, and vigilant anticoagulant management would prevent the need for most reoperative PTEs.

Mixed hematopoietic chimerism induces donor-specific tolerance for lung allografts in rodents.

Mixed hematopoietic chimerism is a state in which bone marrow hematopoietic stem cells from two genetically different animals coexist. We investigated whether mixed hematopoietic chimerism, resulting from the transplantation of host and donor bone marrow into a lethally irradiated rat, would confer donor-specific tolerance to lung allografts. Recipient rats (Fisher or or Wistar Furth [WF]) were irradiated (1,100 cGy) and reconstituted with a mixture of T-cell-depleted syngeneic plus allogeneic bone marrow. After mixed chimerism was documented by the presence of donor- and host-derived cells in the peripheral blood 4 wk after bone marrow reconstitution, mixed chimeras underwent orthotopic left lung transplantation with donor-specific and third-party lung allografts. No immunosuppressive agents were administered after lung transplantation. All donor-specific lung allografts were accepted by mixed chimeras (n = 40), while all third-party grafts (n = 7) were rejected within 10 d, a time course similar to that for grafts transplanted into naive recipients (n = 14). Radiation control recipients (n = 7) who did not develop mixed chimerism because the donor bone marrow had failed to engraft, also rejected donor-specific grafts within 10 d. We conclude that mixed hematopoietic chimerism induces donor-specific transplantation tolerance to lung allografts.