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Verdi J DiSesa

Publications and source records attributed to Verdi J DiSesa.

7 recordsLinked to original sources
PubMed2007

Physician payment for 2007: a description of the process by which major changes in valuation of cardiothoracic surgical procedures occurred.

Throughout the last 3 years, the Society of Thoracic Surgeons (STS) has put forth a major effort towards more accurate valuation of the work performed by cardiothoracic surgeons. The culmination of these efforts was realized on November 1, 2006, when the Centers for Medicare & Medicaid Services published the Final Rule which markedly increased the physician work values for the most frequently performed cardiothoracic surgery procedures. This article recounts the innovative approach taken by the STS during these extended efforts.

Cardiac Surgical Procedures↗
PubMed2006

Contemporary impact of state certificate-of-need regulations for cardiac surgery: an analysis using the Society of Thoracic Surgeons' National Cardiac Surgery Database.

BACKGROUND: Prior research using administrative data associated certificate-of-need (CON) regulation for open heart surgery with higher hospital coronary artery bypass grafting (CABG) volume and lower CABG operative mortality rates in elderly patients. It is unclear whether these findings apply in a general population and after controlling for detailed clinical characteristics and region. METHODS AND RESULTS: Using the Society of Thoracic Surgeons' (STS) National Cardiac Surgery Database, we examined isolated CABG surgery volume, operative mortality, and the composite end point of operative mortality or major morbidity for the years 2000 to 2003. The presence of CON regulations for open heart surgery was ascertained from the National Directory of the American Health Policy Association and by contacting CON administrators. Results were analyzed nationally, by state, and by region (West, Northeast, Midwest, South) and were adjusted for clinical factors and both population density and region with mixed-effects hierarchical logistic regression models. During 2000 to 2003, there were 314,710 isolated CABG surgeries performed at 294 STS hospitals in CON states (n=27, including Washington, DC) and 280 512 procedures at 343 STS hospitals in non-CON states (n=24). Patient clinical characteristics were similar among CON and non-CON hospitals. States with CON regulations tended to have higher population densities and had significantly higher median hospital annual CABG volumes in each of the years 2000 to 2003 (P<0.005). This difference remained significant after adjustment for region and population density. Operative mortality was 2.52% for CON versus 2.62% for non-CON states (P=0.32). There was a significant association between CON law and operative mortality in the South. After adjustment for patient risk factors and region, there was a marginally significant reduction of mortality risk in states with CON regulation (adjusted OR 0.92, 95% CI 0.86 to 1.00). However, this difference was not statistically significant when a revised model accounted for random state effects. Similar volume and outcomes results were seen when the analysis was repeated with data from the national Medicare database. CONCLUSIONS: CON states have significantly higher hospital CABG surgery volumes but similar mortality compared with non-CON states. CON regulation alone is not a sufficient mechanism to ensure quality of care for CABG surgery.

Certificate of Need↗
PubMed2004

New technology, old standards: disparate activated clotting time measurements by the Hemochron Jr compared with the standard Hemochron.

BACKGROUND: Accurate control of the anticoagulation level is important for safe initiation of cardiopulmonary bypass. Using the Hemochron Jr., we consistently noted a higher than customary heparin dose required to achieve an activated clotting time (ACT) that, according to the literature and our quality standards, should be more than 480 seconds. This study was designed to determine whether there existed a significant difference in ACT values measured by the newer Hemochron Jr. and the older Hemochron 801 assay system. METHODS: A total of 30 patients underwent cardiovascular surgical procedures requiring heparinization (300 U/kg). Multiple samples for measurement of the ACT were obtained from all patients before heparinization, after heparinization, during cardiopulmonary bypass, and after protamine administration. Arterial samples were collected, and ACT was determined simultaneously on the same sample using both Hemochron Jr. and Hemochron 801. Activated clotting time data were analyzed with a linear mixed model using an unstructured variance-covariance matrix. RESULTS: Descriptive statistics on all heparinized patients revealed that the Hemochron Jr. yielded ACT results that on average were 121.28 seconds lower than the determination by the standard Hemochron 801 on the same sample of blood. This difference was -139.04 in on-pump cases and -90.51 in off-pump cases, primarily a function of the fact that higher heparin doses and therefore longer ACTs were used in patients having operations using the heart-lung machine. From the linear mixed model, the estimated average paired difference between the Hemochron Jr. and Hemochron 801 was found to be -86.03, yielding a highly significant test statistic (t(28) = -6.18; p < 0.0001). CONCLUSIONS: Lower ACT values determined by Hemochron Jr. are consistent with higher, clinically acceptable ACT values as measured by the Hemochron 801. These findings would suggest that safe levels of anticoagulation are determined in part by the specific assay used.

Blood Coagulation Tests↗
PubMed2003

Use of mitral valve repair: analysis of contemporary United States experience reported to the Society of Thoracic Surgeons National Cardiac Database.

BACKGROUND: The Society of Thoracic Surgeons National Cardiac Database data indicate that the performance of mitral repair has increased significantly (1990 to 23.2%, 1999 to 32.0%, p < 0.0001). We examined contemporary (1999 to 2000) usage of mitral repair in the United States. METHODS: We analyzed National Cardiac Database data to determine the operative approach for a diagnosis of mitral regurgitation. RESULTS: A total of 21,741 isolated and combined mitral valve procedures were identified. The overall frequency of repair was 37.7% (8206). For procedures isolated to the mitral valve, the frequency of repair was 35.7% (3027/8486) whereas repair was more common with concomitant CABG (42.9% [3088/7193], p < 0.0001). The proportion of patients having repair decreased with age (41.2% [386/936] in 20 to 39 years, 36.1% [3513/9746] in > 70 years, p = 0.0016). Repair was more common in males (43.5% [4720/10860]) than females (32.0% [3472/10842], p < 0.0001). Repair was less common as NYHA Class increased (Class I, 47.8% [949/1984] vs Class IV, 33.2% [1803/5427]) and for emergent operative status (21.2% [156/736] vs 38.5% [8000/20773] for elective/urgent, both p < 0.0001). The number of prior operations did not affect the use of repair. Simple annuloplasty was performed in the majority of reported repairs (62.8% [3837/6115]), more so with associated CABG as compared to isolated repair (70.2% [2167/3088] vs 55.2% [1670/3027]; p < 0.0001). CONCLUSIONS: Mitral repair was performed in over one-third of the patients reported in 1999 to 2000 and has increased since the National Cardiac Database inception. Repair usage differed based on sex, age, gravity of illness, and associated procedures. This provides a base line from which to expand the application of repair.

Adult↗
PubMed2002

Direct killing of xenograft cells by CD8+ T cells of discordant xenograft recipients.

BACKGROUND: Long-term pig xenografts in monkeys demonstrated the infiltration of CD8 T cells into pig cartilage xenografts, transplanted into monkeys. The objective of the present study was to determine in an experimental animal model whether CD8 T cells in pig xenograft recipients exert any direct cytotoxic effect on pig cells. METHODS: The killing of xenograft cells by CD8 T cells, obtained from xenograft recipients, was studied in alpha1,3galactosyltransferase knockout mice that were repeatedly injected intraperitoneally with pig kidney membranes. The pig kidney cell line PK15, which shares many antigens with pig kidney membranes, served as a model for xenograft target cells in cytotoxicity assays. Cell lines from other species were also studied as target cells. RESULTS: Lymphocytes obtained freshly from spleens of mice immunized with pig kidney membranes failed to display significant cytotoxic activity against pig cells. However, incubation of these lymphocytes with irradiated PK15 cells and addition of recombinant interleukin (IL)-2 (100 U/mL), on the third day of incubation, resulted in extensive proliferation and expansion of CD8 cytotoxic T lymphocytes (CTL). These CTL, obtained after 12 days of incubation, killed nonspecifically pig, human, and mouse normal and malignant cells. These CTL were not generated in cultures in the absence of stimulatory pig cells or in the absence of IL-2. These CTL could not be generated in cultures of lymphocytes from naive mice that were incubated with PK15 cells and IL-2. CONCLUSIONS: The data obtained imply that CD8 T cells from xenograft recipients can be stimulated in vitro by xenoantigens and IL-2 to differentiate into highly reactive nonspecific CTL that are capable of killing a large variety of xenogeneic and syngeneic cells. Similar in vivo microenvironmental conditions within the xenograft may induce the local differentiation of infiltrating CD8 T cells into CTL that can destroy nonspecifically adjacent xenograft cells. Such cells may not be active outside the xenograft because of the absence of IL-2 in sufficiently high concentrations.

Animals↗
PubMed2002

Elimination of anti-Gal B cells by alpha-Gal ricin1.

BACKGROUND: A major barrier in pig to human organ transplantation is the binding of human anti-Gal to alpha-gal epitopes (Gal alpha 1-3Gal beta 1-4GlcNAc-R) on pig cells, resulting in hyperacute and acute vascular rejection of pig xenografts. Moreover, the immune system in xenograft recipients is activated by these epitopes to produce high affinity anti-Gal, which is also detrimental to xenografts. Production of anti-Gal can be prevented by specific elimination of anti-Gal B cells. This was achieved with the toxin ricin A, coupled to human alpha1-acid glycoprotein modified to carry alpha-gal epitopes. This complex, designated alpha-gal ricin, is targeted in vivo to anti-Gal B cells by interaction with the immunoglobulin molecules (i.e., B cell receptors) on these cells. METHODS: Carbohydrate chains on alpha 1-acid glycoprotein were converted to carry alpha-gal epitopes by enzymatic treatment with recombinant alpha 1,3 galactosyltransferase (alpha 1,3GT). This molecule and ricin A were biotinylated and coupled by avidin to generate alpha-gal ricin. The efficacy of alpha-gal ricin in eliminating anti-Gal B cells was studied in the experimental model of alpha 1,3GT knockout (KO) mice. These mice produce large amounts of anti-Gal immunoglobulin G when immunized with pig kidney membranes, as measured by ELISA with alpha-gal epitopes linked to bovine serum albumin (BSA). In the absence of anti-Gal B cells, these mice lack the ability to produce anti-Gal. RESULTS: Repeated administration of alpha-gal ricin into alpha1,3GT KO mice resulted in elimination of anti-Gal B cells, thereby preventing production of anti-Gal immunoglobulin G after immunization with pig kidney membranes. This prevention of anti-Gal production occurred with doses of alpha-gal ricin that were not toxic to the mice and did not affect production of antibodies with other specificities. CONCLUSIONS: Administration of alpha-gal ricin results in specific elimination of anti-Gal B cells in alpha 1,3GT KO mice. The elimination of these B cells may prove to be helpful in attempts to achieve immune tolerance to alpha-gal epitopes in primates.

Animals↗