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Biomedical subjects

John G Byrne

Publications and source records attributed to John G Byrne.

At least 19 recordsLinked to original sources
PubMed2006

Predicting survival in patients requiring renal replacement therapy after cardiac surgery.

BACKGROUND: We sought to develop and internally validate a prediction score for all-cause in-hospital mortality in patients who have acute renal failure and require renal replacement therapy after cardiac surgery. METHODS: From January 1992 to July 2001, 136 of 14,000 patients (0.9%) had acute renal failure requiring renal replacement therapy after cardiac surgery. Multivariate logistic regression analysis, based on pre-renal replacement therapy variables, was used to construct a predictive score for all causes of in-hospital mortality. Subsequently, the score was validated in 27 patients who underwent surgery between August 2001 and March 2003. RESULTS: In-hospital mortality was 58% (79 of 136). From the logistic regression model, we assigned a score (range, 0 to 6) based on the presence of independent predictors of operative mortality (preoperative creatinine < or = 1.5 mg/dL [odds ratio (OR) = 5.0], hypertension [OR = 4.4], predialysis coma [OR = 9.6], sepsis [OR = 6.4], and total bilirubin > or = 2 mg/dL [OR = 5.6]). Higher scores strongly predicted mortality: patients who scored 3 or higher before the initiation dialysis (n = 54), had a mortality rate of 94% (51 of 54). In contrast, patients who scored 1 or less on this scale (n = 36), had a mortality of 16% (6 of 36). In the validation cohort, the sensitivity of the new score at the cutoff of 2 or fewer points versus 3 or more points was 0.71, the specificity was 0.90, the positive predictive value was 0.92, and the negative predictive value was 0.64. CONCLUSIONS: The prediction score represents a simple and accurate tool for predicting in-hospital mortality associated with renal replacement therapy for cardiac surgery patients before the institution of this resource-intensive treatment.

Acute Kidney Injury↗
PubMed2006

Combined percutaneous coronary intervention and valve surgery.

PURPOSE OF REVIEW: This article reviews unique advantages emerging in valvular heart disease as the technology of invasive cardiology and cardiac surgery begin to merge. RECENT FINDINGS: Minimally invasive valve surgery is increasing in popularity and has helped to reduce morbidity. In addition, preoperative or intraoperative treatment of coronary artery disease by a percutaneous approach has simplified operations and allowed more liberal use of non-traditional incisions. SUMMARY: Percutaneous intervention with drug-eluting stents has provided early evidence for decreased restenosis and improved long-term patency rates. At the same time, cardiac surgery has moved toward less invasive approaches performed in new imaging arenas known as 'hybrid' operating rooms. Combining these technological advances is providing unique solutions to valvular heart disease also requiring revascularization, and will likely become the next horizon for strategies in cardiovascular medicine.

Cardiac Catheterization↗
PubMed2005

Staged initial percutaneous coronary intervention followed by valve surgery ("hybrid approach") for patients with complex coronary and valve disease.

OBJECTIVES: The goal of this study was to determine if a "hybrid" approach to the treatment of complex combined coronary and valve disease is superior to the results predicted by a Society of Thoracic Surgeons' (STS) algorithm with conventional coronary artery bypass graft (CABG)/valve surgery in high-risk patients. BACKGROUND: With advancements in percutaneous coronary interventions (PCIs), some patients requiring coronary revascularization and valve surgery may benefit from a hybrid approach involving initial planned PCI followed by valve surgery, rather than conventional CABG/valve surgery. METHODS: We retrospectively analyzed 26 consecutive patients with coronary artery and valve disease who underwent planned initial PCI followed by valve surgery during the same hospital stay between September 1997 and August 2003. We calculated the predicted mortality at the time of PCI and compared it with the observed mortality. RESULTS: There were 12 male and 14 female patients with a median age of 72 years (range 53 to 91 years). Balloon angioplasty was performed in all patients, followed by stenting in 22 (85%) patients. Within a median of 5 days (range 0 to 14 days), 15 patients (58%) underwent primary and 11 patients (42%) underwent re-operative valve surgery. Operative mortality was 1 of 26 patients (3.8%), dramatically lower than the STS-predicted mortality of 22%. Median blood loss was 900 ml, and 22 patients (85%) required blood transfusions. Survival at 1, 3, and 5 years was 78%, 56%, and 44%, respectively. CONCLUSIONS: Hybrid initial PCI followed by staged valve surgery represents an excellent alternative to conventional CABG/valve surgery in some high-risk patients, particularly those who present in shock after myocardial infarction. Lower mortality rates come at the cost of more bleeding and transfusion requirements.

Aged↗
PubMed2005

Risk factors and outcomes of pancreatitis after open heart surgery.

BACKGROUND: We sought to analyze the risk factors and natural history associated with post-cardiac surgery acute pancreatitis. METHODS: Retrospective analysis of all patients having undergone cardiac surgery at our hospital between January 1, 1992, and October 1, 2001. RESULTS: A total of 10,249 cardiac operations were performed. Thirty-nine (0.4%) patients developed postoperative pancreatitis. There was a higher incidence during the period spanning 1992 through 1996 than 1997 through 2001 (0.6% versus 0.2%, P< .05). Patients with pancreatitis had longer postoperative length of stay (51+/-5 days versus 10+/-1 days, P<.05) and a greater in-hospital mortality rate (28% versus 4%, P<.05) than patients who did not develop pancreatitis. A history of alcohol abuse, cardiac surgery performed during 1992 to 1996, increased cardiopulmonary bypass time, and increased cross-clamp time were independent risk factors for the development of pancreatitis. Multiple-organ failure was an independent predictor for death among patients with pancreatitis. CONCLUSIONS: Although the frequency of post-cardiac surgery pancreatitis is diminishing, it is still associated with significant mortality.

Acute Disease↗
PubMed2005

Postinfarction ventricular septal defect with pseudoaneurysm repair after failed percutaneous closure.

Ventricular septal defect with intramyocardial dissection of the ventricular free wall is a rare complication of myocardial infarction associated with poor prognosis. We describe a patient who developed a ventricular septal defect with intramyocardial dissection of the right ventricular free wall. Initially the patient was successfully stabilized by the placement of a percutaneous closure device. The placement of the device allowed initial hemodynamic recovery of the patient and subsequent definitive surgical repair. This case illustrates the importance of collaboration between interventional cardiologists and cardiac surgeons in the treatment of complex postinfarction ventricular septal defects.

Aneurysm, False↗
PubMed2005

Idiopathic inflammatory aneurysm of the ascending aorta.

Inflammatory aneurysms of the ascending aorta are exceedingly rare. The principal cause of ascending aortic aneurysms remains arteriosclerosis. We present a patient with an ascending aortic aneurysm caused by active inflammatory disease superimposed on complex atherosclerotic disease of the aorta.

Aged↗
PubMed2005

Impact of concomitant coronary artery bypass grafting on hospital survival after aortic root replacement.

BACKGROUND: We examined the impact of concomitant coronary artery bypass grafting (CABG) on hospital survival after aortic root replacement. We sought to determine whether CABG procedures that were not originally planned but rather added after the aortic root procedure was completed (CABG/bailout) skewed the results to shift patients with bad outcomes to the CABG group, making the non-CABG group appear undeservedly low risk. METHODS: Between May 1992 and January 2001, 369 consecutive patients underwent aortic root replacement. Concomitant CABG was required in 95 patients (26%). Indications for CABG were significant coronary artery disease in 73 patients (20%), active endocarditis or acute aortic dissection involving the coronary orifices in 14 patients (4%), and difficulty weaning from bypass because of regional wall motion abnormality from presumed but unconfirmed coronary artery disease or technical error at coronary ostial reimplantation (CABG/bailout) in 8 patients (2%). RESULTS: Operative mortality for the entire cohort was 5.7% (21 patients). The operative mortality rate for the non-CABG group was 0.4% (1 of 274 patients), and for the CABG group, 21% (20 of 95 patients; p < 0.001). Independent predictors of operative mortality in the CABG group were New York Heart Association functional class III or IV (odds ratio, 3.9; 95% confidence interval, 1.07 to 14.5), active endocarditis (odds ratio, 9.2; 95% confidence interval, 2.06 to 41.5), acute aortic dissection (odds ratio, 7.6; 95% confidence interval, 1.81 to 32.0), and failure to use retrograde cardioplegia (odds ratio, 6.4; 95% confidence interval, 1.06 to 38.8). The use of CABG/bailout was not a predictor. CONCLUSIONS: Adding CABG at the end of an aortic root procedure is a rare event, and because it is rare, there is no significant shift of risk as a result of the CABG/bailout patients on the overall CABG group.

Adult↗
PubMed2005

Three dimensional computed tomographic imaging in planning the surgical approach for redo cardiac surgery after coronary revascularization.

OBJECTIVE: Reoperative cardiac surgery after previous coronary artery bypass grafting represents a surgical challenge due to the potential for injury to patent coronary grafts, aorta or right ventricle. Standard preoperative imaging using a coronary angiogram and chest radiograph (CXR) often results in inaccurate assessment of mediastinal anatomy. We aimed to evaluate 3D volume rendered computed tomographic imaging as an adjunct to standard preoperative assessment of patients requiring cardiac surgery in whom coronary artery revascularization had been performed in the past. METHODS: Between January 2003 and January 2004, 33 patients with previous coronary revascularization referred for reoperative cardiac surgery underwent preoperative 3D CT imaging in order to optimize the surgical approach. The mean age in this patient population was 72+/-8 years. The combined evaluation of CXR and conventional angiography offered incomplete insight into pertinent mediastinal topography in 85% of patients (28/33). RESULTS: The correlations for distances of the left internal mammary artery (LIMA) to left anterior descending artery (LAD) graft from the midline and posterior sternum obtained by CT angiography (CTA) and CXR were poor, R=0.56 and 0.49, respectively. The correlation coefficients for distances between the right ventricle and the aorta to the sternum obtained by the same methods were similarly marginal, 0.58 and 0.48, respectively. The correlation coefficients for distances between the LIMA to LAD, circumflex and right coronary artery grafts from the midline obtained by CTA and conventional angiography were 0.54, -0.13 and 0.43, respectively. In seven patients (21%) the surgical strategy was modified based on the location of patent grafts in the mediastinum. The hospital mortality was 17% (5/29). Intraoperative injuries to vital structures were encountered in two patients (7%). No injuries to patent LIMA or the aorta were encountered. CONCLUSIONS: The 3D CT imaging technique is useful in defining the optimal surgical strategy for reoperative cardiac surgery. We found that CTA is superior to CXR and conventional angiography in defining the position of patent grafts and vital structures in relation to the midline and posterior sternum. Preoperative mapping of patent coronary grafts and other vital mediastinal structures reduces the morbidity of the reoperation through modification of surgical approaches.

Aged↗
PubMed2005

Modern surgical treatment of massive pulmonary embolism: results in 47 consecutive patients after rapid diagnosis and aggressive surgical approach.

OBJECTIVES: This study retrospectively reviews an aggressive multidisciplinary approach to the treatment of massive pulmonary embolism, centering on rapid diagnosis with contrast-enhanced computed tomography of the chest to define the location and degree of clot burden and transthoracic echocardiography to document right ventricular strain followed by immediate surgical intervention when appropriate. METHODS: Between October 1999 through February 2004, 47 patients (30 men and 17 women; median age, 58 years; age range, 24-86 years) underwent emergency surgical embolectomy for massive central pulmonary embolism. The indications for surgical intervention were (1) contraindications to thrombolysis (21/47 [45%]), (2) failed medical treatment (5/47 [10%]), and (3) right ventricular dysfunction (15/47 [32%]). Preoperatively, 12 (26%) of 47 patients were in cardiogenic shock, and 6 (11%) of 47 were in cardiac arrest. RESULTS: There were 3 (6%) operative deaths, 2 with preoperative cardiac arrest; 2 of these 3 patients required a right ventricular assist device. In 38 (81%) patients a caval filter was placed intraoperatively. Median length of stay was 11 days (range, 3-75 days). Median follow-up was 27 months (range, 2-50 months); follow-up was 100% complete in surviving patients. There were 6 (12%) late deaths, 5 of which were from metastatic cancer. Actuarial survival at 1 and 3 years' follow-up was 86% and 83%, respectively. CONCLUSION: An aggressive approach to large pulmonary embolus, including rapid diagnosis and prompt surgical intervention, has improved results with surgical embolectomy. We now perform surgical pulmonary embolectomy not only in patients with large central clot burden and hemodynamic compromise but also in hemodynamically stable patients with right ventricular dysfunction documented by means of echocardiography.

Actuarial Analysis↗
PubMed2005

Left ventricular assist device implantation after acute anterior wall myocardial infarction and cardiogenic shock: a two-center study.

OBJECTIVE: Left ventricular assist device (LVAD) insertion after anterior wall myocardial infarction complicated by cardiogenic shock is an accepted modality of support in select patients. Results of primary revascularization for these patients are poor. We seek to determine the outcomes of patients with myocardial infarction and shock who undergo LVAD insertion alone versus surgical revascularization before LVAD insertion. METHODS: Seventy-four patients at 2 institutions underwent LVAD implantation for myocardial infarction and shock over a 12-year period. Twenty-eight underwent direct LVAD placement, and 46 underwent revascularization through coronary artery bypass grafting before LVAD placement. Variables examined included patient demographics, myocardial infarction-LVAD interval, bridge to transplantation, early mortality (< or = 30 days), survival after LVAD placement, and posttransplantation survivals. RESULTS: There were no differences in demographics between the 2 groups. The group undergoing revascularization before LVAD placement had a lower bridge to transplantation, higher early mortality, and lower overall 6- and 12-month survivals after LVAD placement compared with the group undergoing direct LVAD placement (45.50% vs 70.40%, P = .041; 39.10% vs 14.30%, P = .020; 89.3% and 82.1% vs 54.4% and 52.2%, respectively, P = .006). Posttransplantation survival and LVAD explantation rates were equivalent in both groups. CONCLUSIONS: Coronary artery bypass grafting before LVAD insertion for cardiogenic shock complicating myocardial infarction adversely affects survival. Confirmation of these findings would require conducting a large, multicenter, randomized clinical trial comparing revascularization versus LVAD support as primary therapy in this setting.

Coronary Artery Bypass↗
PubMed2005

Atrial endocarditis--the importance of the regurgitant jet lesion.

The jet lesions of valvular regurgitation or intracardiac shunts have been hypothesized to play an important role in the pathogenesis of endocarditis for many years. We describe a case of mitral valve endocarditis that involved the left atrium along the path of a jet lesion. This resulted in atrial endocarditis and pericarditis, both of which complicated her presentation and hospital course. Using transesophageal echocardiography, we were able to directly visualize the path and full extent of infection prior to surgery. Special attention should be focused upon the path of eccentric jets in order to fully define the extent of endocarditis.

Blood Flow Velocity↗
PubMed2005

Valve replacement in women of childbearing age: influences on mother, fetus and neonate.

BACKGROUND AND AIM OF THE STUDY: Currently, there is no clear consensus on the optimal type of cardiac valve prosthesis that should be placed in women of childbearing age. The risks of reoperative surgery for bioprosthetic valves must be weighed against those of anticoagulation therapy required for mechanical valves. Bioprosthetic valves placed in women of childbearing age are not necessarily superior to mechanical valves in terms of maternal or fetal outcomes. METHODS: A retrospective analysis was performed of early and late outcome in 103 women of childbearing age (mean age 28.3 +/- 5.1 years; range: 18-35 years) who underwent mechanical (n = 63) or biological (n = 40) valve replacement between January 1982 and July 2002. RESULTS: Eleven of the 40 women (28%) with biological valves had 19 pregnancies (13 vaginal births; three caesarean sections). Twelve of the 63 women (19%) with mechanical valves had 37 pregnancies (nine vaginal births, four caesarean sections). All of the women with mechanical valves became pregnant while receiving warfarin, and were subsequently placed on heparin or enoxaparin. No bleeding complications or birth defects were observed in either group. The incidence of miscarriages (32% (12/37) versus 11% (2/19), p = 0.09) and therapeutic abortions (32.4% (12/37) versus 5.3% (1/19), p = 0.06) were greater in the group with mechanical valves than with bioprosthetic valves. Freedom from reoperation at five and 10 years for biological versus mechanical valves was 79% versus 90%, and 38% versus 82%, respectively (p < 0.01), with no reoperative mortality. CONCLUSION: Biological valves are recommended in women of childbearing age, despite the fact that no birth defects were seen in children born to women with mechanical valves on warfarin, because the teratogenic effects of warfarin may be masked by the high rate of miscarriages and therapeutic abortions in this group.

Adolescent↗
PubMed2004

Frequency and impact of delayed decisions regarding heart transplantation on long-term outcomes in patients with advanced heart failure.

OBJECTIVES: We sought to characterize decisions regarding listing of heart transplant candidates and to determine the impact of delayed listing for a transplant on survival. BACKGROUND: Evaluation and listing for heart transplantation have evolved over the past decade, with the complex decision process often extending beyond the time of initial review. Little is known about the current impact of decisions and timing of listing on outcomes. METHODS: Decisions were prospectively recorded during the initial committee discussions regarding patients referred for heart transplant evaluation. Survival and transplantation rates were assessed. RESULTS: A total of 214 patients were evaluated for heart transplantation (age 49 +/- 11 years, ejection fraction 21 +/- 9%, New York Heart Association class III +/- I, peak oxygen consumption 13 +/- 4 ml/kg/min). At the initial evaluation, 44% of patients were deemed eligible, 25% were potentially eligible, 19% were ineligible, and 12% were deferred. For eligible patients, 37% of patients were listed within 10 days of evaluation, and a total of 71% of patients were ever listed. Regardless of transplantation, the three-year survival rate in eligible patients not listed early was similar to that in patients listed immediately (85% vs. 77%, p = 0.34). Ineligible and potentially eligible patients had a higher three-year mortality rate than did eligible patients if transplantation occurred (51% vs. 17%, p < 0.001) or not (57% vs. 19%, p = 0.04). CONCLUSIONS: Using current accepted guidelines, many patients referred for transplant evaluation were not considered eligible for transplantation, and those who were eligible were not often listed immediately. Eligible patients not listed initially did well in the long term, and patients with relative contraindications had worse outcomes with or without a transplant.

Decision Making↗
PubMed2004

Outcomes in patients with normal serum creatinine and with artificial renal support for acute renal failure developing after coronary artery bypass grafting.

This retrospective study of cardiac surgical patients with normal serum creatinine who developed acute renal failure requiring artificial renal support was undertaken to (1) determine the prevalence of acute renal failure and hospital mortality in this subgroup, (2) identify the independent predictors of early mortality, and (3) determine long-term survival and prognosis.

Acute Kidney Injury↗
PubMed2004

Surgical management of complications of percutaneous coronary rotational atherectomy interventions.

Percutaneous coronary interventions have progressed from angioplasty and intracoronary stents to the more aggressive rotational atherectomy devices. These technically complex procedures are typically performed on the more diseased anatomy, which causes the likelihood of complications to be more common. In this report, we present our experience with three unusual complications and their surgical management.

Aged↗
PubMed2004

Left anterior descending coronary endarterectomy: early and late results in 196 consecutive patients.

BACKGROUND: With advances in percutaneous coronary interventions, many patients now referred for coronary artery bypass grafting have diffuse coronary artery disease. We undertook this retrospective study to determine whether left anterior descending (LAD) coronary endarterectomy is a safe and effective long-term adjunct to coronary artery bypass grafting in patients who cannot otherwise be completely revascularized. METHODS: Between January 1992 and March 2000, 196 of 7,633 (2.5%) consecutive patients underwent LAD coronary endarterectomy with coronary artery bypass grafting. Median age was 67 years (range, 33 to 97 years), 101 patients (52%) had unstable angina, and 182 (93%) were in New York Heart Association class III or IV. Thirty-three patients (17%) had ongoing myocardial infarction; another 17 (9%) had myocardial infarction less than 1 month. Thirty patients (15%) required intraaortic balloon pump preoperatively and 19 (10%) were reoperations. RESULTS: All patients underwent LAD endarterectomy with coronary artery bypass grafting to the LAD. The left internal mammary artery was grafted to the LAD in 151 patients (77%), and 46 of 151 (30%) of these required an additional vein patch to the endarterectomized bed. Concomitant valve procedures were performed in 8 (4%) patients. Overall hospital mortality was 3% (6 of 196). Perioperative myocardial infarction in the LAD territory was 3%. One-year survival was 94% (95% confidence interval, 90% to 97%), whereas 5-year survival was 74% (95% confidence interval, 66% to 80%). Freedom from cardiac events (angina, myocardial infarction, congestive heart failure, percutaneous coronary interventions) was 90% (95% confidence interval, 84% to 94%) at 1 year and 84% (95% confidence interval, 75% to 90%) at 5 years. CONCLUSIONS: Despite the presence of diffuse coronary artery disease, coronary artery bypass grafting with LAD endarterectomy offers excellent results with very low hospital mortality and morbidity, and favorable long-term survival.

Adult↗