Biomedical subjects

Thomas Prendergast

Publications and source records attributed to Thomas Prendergast.

4 recordsLinked to original sources

PubMed2005

Lack of sensitization and equivalent post-transplant outcomes with the Novacor left ventricular assist device.

BACKGROUND: Ventricular assist devices (VADs) are increasingly used to support critically ill heart failure patients awaiting transplantation. Previous work has focused on the Thoratec Heartmate VE device, use of which is associated with pre-formed antibody production. We reviewed our cumulative experience with the Worldheart Novacor VAD as a bridge to transplantation (BTT). METHODS: From January 1989 through October 2002, 39 patients required a VAD bridge, with 26 of 39 surviving to transplantation. Antibody levels were assessed by complement-dependent cytotoxicity assay at routine intervals and expressed as panel reactive antibody (PRA) levels. Post-transplant allograft rejection, coronary vasculopathy, and survival were compared between Novacor-supported patients and non-VAD transplant recipients. RESULTS: PRA values did not significantly change after VAD implantation (12.4% +/- 11.2% vs 14.8% +/- 12.3%, p = 0.28). Survival for the BTT patients was 80.4%, 75.7%, 64.0%, 64.0%, and 64.0%, respectively, for 1, 3, 5, 7, and 10 years post-transplant, with similar results for non-BTT patients. The freedom from coronary vasculopathy was 90.2%, 90.2%, 72.2%, and 72.2%, respectively, at 1, 3, 5, and 7 years post-transplant. CONCLUSIONS: First, to our knowledge, this study is the first to examine the incidence of allosensitization after Novacor implant in detail. In contrast with previous results of work with other VAD systems, as assessed by PRA levels, Novacor patients did not become sensitized. Second, compared with 220 non-BTT patients who received transplants during a similar time frame, Novacor BTT patients had equivalent rejection profiles and survival. Finally, the incidence of transplant-associated coronary artery disease was lower than in previous reports.

Adult↗

PubMed2004

Is off-pump revascularization better for patients with non-dialysis-dependent renal insufficiency?

BACKGROUND: Renal dysfunction is a well-recognized complication following coronary artery bypass grafting (CABG). Coronary revascularization without cardiopulmonary bypass (CPB) has been shown to minimize renal injury in patients with normal preoperative renal function who undergo elective procedures. The purpose of this study was to define the effect of an off-pump revascularization strategy on the incidence of postoperative renal failure and survival of patients with preexisting renal dysfunction. METHODS: From January 1, 1999, to December 1, 2002, a total of 371 patients were identified as having a preoperative creatinine concentration greater than or equal to 1.5 mg/dL. This number included 291 patients who did not need hemodialysis or peritoneal dialysis to support renal function. These patients were subdivided into those undergoing traditional CABG with CPB (103 patients) and those undergoing off-pump revascularization (188 patients) whose demographic, operative, and outcome information was retrospectively reviewed and compared. RESULTS: The off-pump cohort was older than the on-pump cohort (70 +/- 9.6 versus 66 +/- 10.9 years; P =.002), had a lower prevalence of previous myocardial infarction (35% versus 50%; P =.008), and had a modestly higher mean left ventricular ejection fraction (0.47 +/- 0.01 versus 0.43 +/- 0.01; P =.017). Otherwise the groups were well matched. The mean preoperative serum creatinine and creatinine clearance values were not significantly different (1.8 +/- 0.5 versus 1.9 +/- 0.6 mg/dL [ P =.372] and 45.1 +/- 15.5 versus 46.8 +/- 17.2 mL/min [ P =.376] for the off-pump and on-pump cohorts, respectively). There was a significant reduction in postoperative renal failure (17% versus 9% of patients; P =.020) and need for new dialysis (10% versus 3% of patients; P =.022) when CPB was eliminated. Intermediate-term survival analysis revealed a survival benefit for the off-pump group (70% versus 57%) at 42 months, although this value did not reach statistical significance ( P =.143). CONCLUSION: The results of this study suggested that patients with preoperative non-dialysis-dependent renal insufficiency have more favorable outcome when revascularization is done off pump. Avoidance of CPB results in (1) a reduction in the incidence of postoperative renal failure; (2) a reduction in the need for new dialysis; and (3) improved in-hospital and midterm survival.

Adult↗

PubMed2003

Multivessel off-pump revascularization in patients with severe left ventricular dysfunction.

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of multivessel beating heart revascularization in a high-risk group of patients with severe left ventricular dysfunction as well as to provide intermediate survival and quality of life data. METHODS: Our prospectively updated database was queried to extract all patients with left ventricular ejection fraction < or =30% who underwent beating heart revascularization. Standard demographics, clinical profiles and outcomes were collected. Outcomes were compared with Society of Thoracic Surgeons (STS) benchmarks for all coronary artery bypass grafting (CABG) patients. Telephone interviews were conducted and survival and quality of life data were tabulated. In addition, morbidity and mortality outcomes were compared with a concurrent cohort of patients with similarly impaired left ventricular function who underwent conventional coronary artery bypass. RESULTS: One hundred off-pump coronary artery bypass grafting patients were identified and follow-up was 93% complete in these patients. Mean age was 67+/-10.5 years and mean ejection fraction was 26+/-4%. Twenty-one percent were females. Balloon counterpulsation support was used liberally in the perioperative period. Patients received a mean of 3.5 grafts with 83% internal mammary artery use. Observed mortality was 3% with a predicted mortality of 5.3%. Observed to expected ratio was 0.56. Incidence of adverse events compared favorably with both that reported in the STS for all CABG patients regardless of left ventricular function, and also to a concurrent CABG cohort. One-year survival was 85%. Freedom from cardiac readmission was 88% and freedom from angina was 83%. No patient required repeat percutaneous or surgical intervention. CONCLUSIONS: We conclude that multivessel off-pump revascularization in patients with severe left ventricular dysfunction is a safe and effective alternative to conventional grafting. Long-term follow-up is mandatory to confirm these encouraging intermediate outcomes.

Aged↗

PubMedDate not supplied

Multivessel off-pump revascularization in patients with significant left main coronary artery stenosis: early and midterm outcome analysis.

BACKGROUND: The presence of significant left main stenosis (> or =50%) has been considered a relative contraindication to the use of off-pump coronary artery bypass (OPCAB) stemming from well-documented hemodynamic perturbations during the displacement of the heart. We examined our experience with patients with critical left main stenosis (LMS) to assess the safety and feasibility of OPCAB in this subgroup. METHODS: Our prospectively updated database was queried to identify all patients with severe left main disease who underwent isolated coronary revascularization between January 1, 1999 and May 31, 2002. This query yielded 234 on-pump and 420 off-pump patients with significant LMS whose clinical information was retrospectively reviewed. RESULTS: The groups were well matched with regard to gender, left ventricular function, surgical priority, and severity of angina. The conventional coronary artery bypass (CABG) group was significantly younger than the OPCAB group and had a higher incidence of a previous myocardial infarction. Patients in the CABG cohort were more likely than OPCAB patients to remain ventilated after 24 hours, require placement of intraoperative or postoperative intraaortic balloon pump, or suffer from postoperative renal failure. There was a decrease in mortality (6.4% vs. 1.9%; p = 0.006) when CPB was eliminated. Intermediate term survival analysis revealed a significant survival benefit in the off-pump group (p = 0.007). CONCLUSIONS: Multivessel off-pump revascularization in patients with severe left main disease is a safe and effective alternative to conventional bypass grafting and conveys a survival benefit.

Adult↗