PubMed Health⌕ Search

Biomedical subjects

Nader Moazami

Publications and source records attributed to Nader Moazami.

At least 19 recordsLinked to original sources
PubMed2007

Implantable cardioverter-defibrillators improve survival after coronary artery bypass grafting in patients with severely impaired left ventricular function.

OBJECTIVE: Patients with severe left ventricular (LV) dysfunction have a poor long term survival despite complete surgical revascularization. Recent data suggests that the use of Implantable Cardioverter-Defibrillator (ICD) improves survival in patients with severe LV dysfunction. We compared the survival impact of ICD implantation in patients with severe LV dysfunction who underwent CABG. METHODS: Between January 1996 and August 2004, 305 patients with LV ejection fraction (EF) < or = 25% had CABG surgery at our institution. Demographics of patients who had received an ICD (ICD+) in the post -operative period was compared to those without ICD (ICD-). Survival was evaluated by the Kaplan-Meier method. RESULTS: Of the entire group, 35 (11.5%) patients received an ICD with a median of 2 (+/-2) years after CABG. Indication for ICD implantation was clinical evidence of non sustained ventricular tachycardia (NSVT). There were no differences between the 2 groups with respect to age, gender, NYHA classification, number of bypasses, or other co-morbidities. Survival at 1, 3 and 5 years was 88%, 79%, and 67% for the ICD- group compared to 94%, 89% and 83% for the ICD+ group, respectively (figure, p < 0.05). CONCLUSION: Implantation of ICD after CABG confers improved short and long term survival benefit to patients with severe LV dysfunction. Prophylactic ICD implantation in the setting of severe LV dysfunction and CABG surgery should be considered.

Aged↗
PubMed2007

Long-term outcomes in valve replacement surgery for infective endocarditis.

BACKGROUND: Infective endocarditis is associated with a high rate of long-term mortality. Patients with a history of intravenous drug use (IVDU) are at increased risk for infective endocarditis. However, few studies have reported results of surgical treatment on this population. We present 19.5 years of experience with surgically treated patients with infective endocarditis. METHODS: A retrospective study of all cardiac surgeries with a diagnosis of infective endocarditis at a single institution from 1986 to 2005 was performed. Logistic stepwise regression with an end point of operative mortality was done. Variables were age, gender, race, history of drug use, previous valve surgery, and previous valve replacement. Perioperative and outcome variables were compared between IVDU and non-IVDU populations. RESULTS: The IVDU population required surgery at a younger age (39 +/- 9 years versus 54 +/- 15 years; p < 0.001). Overall operative mortality was 12% (41/346). The perioperative complication rate was similar for both groups. When adjusted for age, the two groups had similar long-term survival (p = 0.78). Kaplan-Meier estimator showed that survival at 10 and 15 years was 66% and 54% for IVDU and 56% and 42% for non-IVDU (number at risk, 19, 11, and 61, 28, respectively; p = 0.137). Reoperation for recurrent infective endocarditis was necessary in 9 (17%) of 52 of the IVDU group versus 14 (5%) of 270 of the non-IVDU group (p = 0.03). CONCLUSIONS: Patients with a history of IVDU required reoperation for recurrent infective endocarditis at a significantly higher rate than the non-IVDU patients. Long-term survival was similar between the younger IVDU population and the older non-IVDU population. Anticipated life span is one of many factors when considering prosthetic valve choice in this population.

Adult↗
PubMed2006

Low-dose dobutamine tissue-tagged magnetic resonance imaging with 3-dimensional strain analysis allows assessment of myocardial viability in patients with ischemic cardiomyopathy.

BACKGROUND: Tissue-tagged magnetic resonance imaging (MRI) with 3-dimensional (3D) myocardial strain analysis allows quantitative assessment of myocardial contractility. We assessed the hypothesis that 3D strain determination at rest and with low-dose dobutamine would discriminate between viable and nonviable myocardium in patients with ischemic cardiomyopathy (ICM). METHODS AND RESULTS: MRI with radiofrequency tissue-tagging at rest and with low-dose dobutamine was performed in 16 normal volunteers and 14 patients with ICM. Three-dimensional global and regional circumferential strains (Ecc) were computed for all subjects at rest and with dobutamine. Results were compared with clinically indicated conventional viability studies. Compared with normal volunteers, global left ventricular Ecc was significantly decreased in patients with ICM at rest (-0.15+/-0.06 versus -0.27+/-0.03; P<0.001) and with dobutamine (-0.17+/-0.08 versus -0.37+/-0.10; P<0.001). Ecc was significantly decreased in nonviable regions compared with viable segments at rest (-0.08+/-0.06 versus -0.17+/-0.10; P<0.001) and with dobutamine (-0.07+/-0.06 versus -0.21+/-0.11; P<0.001). Ecc in viable segments increased significantly in response to dobutamine (P=0.04), whereas Ecc did not change in nonviable segments (P=0.50). Normal controls (96 segments) had increased Ecc at rest (-0.27+/-0.07) and with dobutamine (-0.37+/-0.15) compared with both viable and nonviable regions in ICM patients (P<0.001). CONCLUSIONS: Noninvasive dobutamine tissue-tagged MRI with calculation of 3D strain allows the identification, quantification and display of regionally varying ventricular function. The response of systolic strain to low-dose dobutamine has significant promise in discriminating between viable and nonviable myocardium.

Aged↗
PubMed2006

Prosthesis-patient mismatch after aortic valve replacement: impact of age and body size on late survival.

BACKGROUND: The purpose of this study was to identify patient subgroups in which prosthesis-patient mismatch most influenced late survival. METHODS: Over a 12-year period, 1,400 consecutive patients underwent bioprosthetic (933 patients) or mechanical (467) aortic valve replacement. Prosthesis-patient mismatch was defined as prosthetic effective orifice area/body surface area less than 0.75 cm2/m2 and was present with 11% mechanical and 51% bioprosthetic valves. RESULTS: With bioprosthetic valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 68% +/- 7% mismatch versus 75% +/- 7% no mismatch, p < 0.02) but not older patients (p = 0.47). Similarly, with mechanical valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 62% +/- 11% versus 79% +/- 4%, p < 0.005) but not older patients (p = 0.26). For small patients (body surface area less than 1.7 m2), prosthesis-patient mismatch did not impact survival with bioprosthetic (p = 0.32) or mechanical (p = 0.71) valves. For average-size patients (body surface area 1.7 to 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with both bioprosthetic (p < 0.05) and mechanical (p < 0.005) valves. For large patients (body surface area greater than 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with mechanical (p < 0.04) but not bioprosthetic (p = 0.40) valves. CONCLUSIONS: Prosthesis-patient mismatch had a negative impact on survival for young patients, but its impact on older patients was minimal. In addition, although prosthesis-patient mismatch was not important in small patients, prosthesis-patient mismatch negatively impacted survival for average-size patients and for large patients with mechanical valves.

Adult↗
PubMed2006

Does the presence of preoperative mild or moderate coronary artery disease affect the outcomes of lung transplantation?

BACKGROUND: Significant coronary artery disease (CAD) is an exclusion criterion for lung transplantation at most centers. However, the impact of preoperative noncritical CAD (single or multivessel mild <30% or moderate 30% to 50% stenosis) on the outcomes of lung transplantation is unknown. METHODS: A retrospective review of 268 adult patients who underwent lung transplantation between June 1998 and June 2003 at Barnes-Jewish Hospital, a tertiary care center affiliated with Washington University School of Medicine, was performed. RESULTS: Two hundred ten patients had coronary angiography performed as part of their pretransplantation evaluation. Among these patients, 177 patients had no CAD, and 33 patients (mild, 16; moderate, 17) had noncritical CAD. Patients with noncritical CAD were older (59 versus 55 years, p < 0.001) and had a higher prevalence of diabetes (24% versus 9%, p = 0.014) and systemic hypertension (58% versus 36%, p = 0.004) than patients without CAD. There was no significant difference in the underlying lung disease, other comorbidities, type of lung transplantation performed, early postoperative complications, and hospital or late mortality between recipients with or without CAD. Among the patients with noncritical CAD, there was no hospital mortality and no late cardiac mortality. Three recipients with preoperative moderate CAD developed late ischemic cardiac events, and revascularization was performed in 2 of these recipients. Long-term survival was similar among recipients with or without preoperative CAD. CONCLUSIONS: Preoperative noncritical (mild or moderate) CAD was not associated with increased perioperative morbidity or mortality, and it did not adversely affect short-term or long-term survival. Late ischemic events developed in 18% of the recipients with moderate CAD disease with no effect on mortality.

Adult↗
PubMed2006

Left ventricular wall stress in patients with severe aortic insufficiency with finite element analysis.

BACKGROUND: Severe aortic insufficiency (AI) with preserved left ventricular (LV) function may be associated with a long asymptomatic period and unpredictable course on medical therapy. Since myocardial wall stress is closely related to both pathologic cardiac remodeling and ultimately to LV decompensation, a more accurate description of regional wall stress may improve our ability to appropriately manage these patients. The objective of this study was to define differences in instantaneous global and regional three-dimensional end-systolic maximum principal stress (ESS) between normal patients and patients with AI, both before and after aortic valve replacement (AVR) using magnetic resonance imaging (MRI) and finite element analysis (FEA). METHODS: Magnetic resonance imaging was performed on 20 normal volunteers and 14 patients with moderate to severe AI with normal systolic function (ejection fraction: 57 +/- 0.6) before and after AVR. Finite element analysis was utilized to estimate global and regional ESS. RESULTS: Both global (p < 0.001) and regional (p < 0.001 in all segments) ESS were significantly higher in the preoperative AI patients when compared with their postoperative values and normal controls. Postoperative ESS was significantly lower than the normal controls (p = 0.002). CONCLUSIONS: Three-dimensional regional and global end-systolic LV wall stress can be determined by MRI and finite element analysis. Values of ESS in patients with chronic AI were elevated prior to AVR and normalized after AVR. This method may have considerable potential as a noninvasive, clinically applicable index of regional LV geometry and function that may help with the serial evaluation of patients with AI.

Adult↗
PubMed2006

A new era in the surgical treatment of atrial fibrillation: the impact of ablation technology and lesion set on procedural efficacy.

BACKGROUND/OBJECTIVE: While the Cox-Maze procedure remains the gold standard for the surgical treatment of atrial fibrillation (AF), the use of ablation technology has revolutionized the field. To simplify the procedure, our group has replaced most of the incisions with bipolar radiofrequency ablation lines. The purpose of this study was to examine results using bipolar radiofrequency in 130 patients undergoing a full Cox-Maze procedure, a limited Cox-Maze procedure, or pulmonary vein isolation alone. METHODS: A retrospective review was performed of patients who underwent a Cox-Maze procedure (n = 100), utilizing bipolar radiofrequency ablation, a limited Cox-Maze procedure (n = 7), or pulmonary vein isolation alone (n = 23). Follow-up was available on 129 of 130 patients (99%). RESULTS: Pulmonary vein isolation was confirmed by intraoperative pacing in all patients. Cross-clamp time in the lone Cox-Maze procedure patients was 44 +/- 21 minutes, and 104 +/- 42 minutes for the Cox-Maze procedure with a concomitant procedure, which was shortened considerably from our traditional cut-and-sew Cox-Maze procedure times (P < 0.05). There were 4 postoperative deaths in the Cox-Maze procedure group and 1 in the pulmonary vein isolation group. The mean follow-up was 13 +/- 10, 23 +/- 15, and 9 +/- 10 months for the Cox-Maze IV, the pulmonary vein isolation, and the limited Cox-Maze procedure groups, respectively. At last follow-up, freedom from AF was 90% (85 of 94), 86% (6 of 7), and 59% (10 of 17) in the in the Cox-Maze procedure group, limited Cox-Maze procedure group, and pulmonary vein isolation alone group, respectively. CONCLUSIONS: The use of bipolar radiofrequency ablation to replace Cox-Maze incisions was safe and effective at controlling AF. Pulmonary vein isolation alone was much less effective, and should be used cautiously in this population.

Atrial Fibrillation↗
PubMed2006

Should UNOS Status 2 patients undergo transplantation?

BACKGROUND: With recent improvements in medical and device therapy, the benefit of cardiac transplantation for UNOS Status 2 patients has been questioned. No randomized trial has been performed to compare transplantation versus contemporary medical therapy. METHODS: Between January 1996 and December 2003, 203 patients were listed at our institution for heart transplantation as UNOS Status 2. We performed a retrospective review to determine outcomes in these patients. RESULTS: Demographics of this cohort revealed a mean age of 52 years, female sex in 28%, and ischemic etiology in 47%. Eighty-one patients (40%) had an implantable cardiac defibrillator. A total of 64 patients (32%) had to be upgraded in their UNOS status, with 9 requiring a left ventricular assist device. Of the entire group, 95 (47%) underwent transplantation at a mean time of 303 days, 45 (22%) died while waiting at a mean time of 397 days, and 24 (12%) were removed from the waiting list due to deterioration in medical condition such that transplantation was no longer an option. The remaining patients continue to wait or have been removed from consideration due to improved condition. Survival at 1- and 3-years postlisting was 94% and 87% for patients who received transplants compared to 81% and 57% for patients who did not receive transplants (P < .01). CONCLUSION: A significant number of patients listed as Status 2 are upgraded in UNOS status or die while on the waiting list. Early and midterm survival is significantly better with transplantation. Identification of variables associated with deterioration may allow for better risk stratification in the future. At this point, transplantation offers the best outcome.

Cohort Studies↗
PubMed2005

Principal strain orientation in the normal human left ventricle.

BACKGROUND: Methods that can improve the accuracy of application of directed intervention in the treatment of coronary artery disease deserve investigation. Magnetic resonance imaging with tissue tagging allows for noninvasive, quantitative determination of regionally varying minimum principal strain. Because the directional vector of minimum principal strain has been shown to be sensitive to ischemic involvement, my colleagues and I sought to fully characterize the normal range of vector direction in the in vivo human left ventricle at rest and during inotropic stimulation. METHODS: Tagged magnetic resonance imaging image sets were acquired in 20 healthy volunteers at rest and during dobutamine infusion. Strain was computed from the measured displacement data by using finite element software. Orientation of minimum principal strain was characterized by measuring the angle (principal strain angle) between the minimum principal strain vector and the local circumferential-longitudinal plane. Values of this angle were computed in 6 ventricular regions and globally. RESULTS: Resting values of the principal strain angle were small in every region, confirming that maximal normal myocardial contraction occurs primarily in the circumferential-longitudinal plane. Angles were similar during dobutamine infusion. Comparisons between ventricular walls, both at rest and with dobutamine, revealed no marked regional differences in the principal strain angle. CONCLUSIONS: The direction of maximal myocardial contraction is known to change with ischemic injury to the myocardium and can be a sensitive, regionally varying index of myocardial ischemia. The critical first step in the clinical application of this technology is to accurately characterize normal ranges of principal strain angles.

Adult↗
PubMed2005

Impact of complete revascularization on long-term survival after coronary artery bypass grafting in octogenarians.

BACKGROUND: Complete revascularization is important in young patients undergoing coronary artery bypass grafting, but this principle remains less absolute in elderly patients. The purpose of this study was to determine how complete revascularization influenced long-term survival after coronary artery bypass grafting in octogenarians. METHODS: From 1986 to 2003, 500 consecutive patients 80 to 94 years of age underwent coronary artery bypass grafting. Complete revascularization was defined as placement of at least one graft to each of the three major vascular regions that included a 50% diameter lesion. Revascularization was complete in 400 (80%) patients and incomplete in 100 (20%) patients. Mean (+/- standard deviation) follow-up was 51 +/- 41 months and was 99% complete (2,102 total patient-years). RESULTS: Operative mortality was 8% +/- 2% (+/-95% confidence interval) and was statistically lower with complete (7% +/- 3%) versus incomplete (13% +/- 7%) revascularization (p < 0.05). Of 459 operative survivors, there were 261 late deaths. Multivariate regression analysis identified six independent predictors of late death: earlier operative year, male sex, peripheral or cerebrovascular disease, congestive heart failure, and incomplete revascularization (p < 0.03 for all). Excluding operative deaths, mean survival (Kaplan-Meier) was 82 months with complete revascularization compared with 65 months with incomplete revascularization (p < 0.008). Survival was 62% +/- 3% with complete versus 45% +/- 6% with incomplete revascularization at 5 years and 39% +/- 3% with complete versus 25% +/- 6% with incomplete revascularization at 8 years (p < 0.008). CONCLUSIONS: In octogenarians undergoing coronary artery bypass grafting, complete revascularization correlated with improved long-term survival, increasing mean survival by almost 25% compared with incomplete revascularization.

Age Factors↗
PubMed2005

Radial artery grafts in women: utilization and results.

BACKGROUND: Despite a known survival benefit with the use of the left internal mammary artery, it is used less frequently in women when compared with men. This study evaluated the hypotheses that the radial artery graft is used less frequently in women compared with men, that the radial artery is smaller in women compared with men, and that the use of the radial artery influences operative mortality and long-term survival in women. METHODS: The use of a radial artery graft was evaluated in 2,633 patients who underwent isolated coronary artery bypass. Radial artery size and flow were compared in 207 patients who had intraoperative radial artery diameter and flow measurements. Propensity scoring was utilized to compare short- and long-term outcomes in a matched cohort of 588 women. RESULTS: Of 862 women (33%) who had isolated coronary artery bypass grafting, only 301 (35%) received a radial artery graft versus 44% of men (786 of 1,771, p < 0.001). Radial artery size and flow were significantly less in women. Operative mortality was not different between women with a radial artery graft and women without; however, 5-year survival was significantly better in women with a radial artery graft than in those without. CONCLUSIONS: Women received fewer radial artery grafts than men. Radial artery size and flow were significantly less in women than in men. Use of a radial artery graft did not influence operative mortality among women. However, 5-year survival among women who received a radial artery graft was significantly better than among women who did not.

Aged↗
PubMed2005

Blood transfusions decrease the incidence of acute rejection in cardiac allograft recipients.

BACKGROUND: Cardiac transplant recipients frequently receive a large number of transfusions. The objective of this study was to determine whether there is an association between total number of blood transfusions and cardiac allograft rejection. METHODS: A retrospective analysis of all cardiac transplants between October 1, 1997, and December 31, 2001, was performed. Total number of transfusions, total number of rejection episodes Grade 3A or more, rejection-free survival, and overall survival were analyzed. Comparisons between patients bridged to transplantation with a Novacor left ventricular assist device (LVAD) and the primary transplant group were also made. RESULTS: Eighty-two patients were transplanted. Fifteen were bridged to transplantation, and 67 underwent primary heart transplantation. Age and sex were similar for the LVAD group and the primary transplant group (45 +/- 11 vs 47 +/- 15 years and 67% vs 58% male sex, respectively). Mean follow-up was 658 +/- 486 days for the LVAD group and 708 +/- 548 days for the primary transplant group. Transfusions received were 50 +/- 34 U of packed red blood cells for the LVAD group and 7 +/- 12 for the primary transplant group (p < 0.001). There were no differences in donor characteristics between the 2 groups. The incidence of acute rejection within 1 year was 27% for the LVAD group and 39% for the primary transplant group (p = .28). Freedom from rejection was 71% at 1 year in the LVAD group compared with 59% for the primary transplant group (p = 0.39). In all 82 patients, the total number of transfusions was inversely correlated with the development of acute rejection (p = 0.011). Survival was 80% and 62% for the LVAD group at 1 and 3 years after transplantation and 88% and 85%, respectively, for the primary transplant group (p = 0.045). CONCLUSIONS: The number of blood transfusions received by heart transplant recipients is inversely related with the number of acute rejection episodes.

Adult↗
PubMed2005

Outcome of lung transplantation for patients requiring concomitant cardiac surgery.

BACKGROUND: The clinical results of lung transplantation and concomitant cardiac surgery are unclear. The effect of cardiopulmonary bypass on the pulmonary allograft is controversial, and the effect of cardiac arrest and cardiac surgery in this setting is unknown. Our aim was to review the operative results and long-term survival in this group of patients. METHODS: A retrospective review of all lung transplantations between 1988 and 2003 was performed. Patients who had concomitant cardiac surgery during lung transplantation were compared with those who underwent lung transplantation alone. The variables analyzed included allograft ischemic times, use of cardiopulmonary bypass, early graft dysfunction, postoperative morbidity, survival, length of mechanical ventilation, length of stay in the intensive care unit, and overall hospital stay. RESULTS: During this period, 35 of 700 lung transplant recipients (15 single and 20 bilateral transplantations) underwent concomitant cardiac surgery. The cardiac procedures were for patent foramen ovale (n = 18), atrial septal defect (n = 9), ventricular septal defect (n = 2), coronary bypass (n = 4), and "other" (n = 2). Allograft ischemic time, use of extracorporeal membrane oxygenation, length of hospital stay, operative mortality, and survival were not significantly different between the 2 groups. Ventilator time and intensive care unit stay were longer in the cardiac surgery group. CONCLUSIONS: Cardiac surgery at the time of lung transplantation can be performed with acceptable morbidity and mortality. The immediate and long-term survival in these patients is similar to that of other lung transplant recipients. Lung transplantation should continue to be offered to patients with normal ventricular function who require concomitant limited cardiac surgery.

Adult↗
PubMed2005

Different roles for matrix metalloproteinase-2 and matrix metalloproteinase-9 in the pathogenesis of cardiac allograft rejection.

Recent studies have shown an increased expression of several matrix metalloproteinases (MMP) during cardiac, renal and pulmonary allograft rejection. To further define the roles of MMP-2 and MMP-9 in the pathogenesis of cardiac allograft rejection, BALB/c cardiac allografts were transplanted into MMP-2-deficient (-/-) and MMP-9-/- mice. Allografts rejected by wild-type mice revealed a significant increase in MMP-2 and MMP-9 expression. MMP-2-deficiency significantly prolonged allograft survival time. Functioning allografts harvested from MMP-2-/- mice showed lower cellular infiltration and fibrosis than rejected allografts harvested from MMP-2+/+ mice at the same time. In contrast, MMP-9-deficiency significantly decreased allograft survival time. Functioning allografts harvested from MMP-9+/+ mice showed lower cellular infiltration and fibrosis than rejected allografts harvested from MMP-9-/- mice at the same time. MMP-2-/- recipients showed decreased T-cell alloreactivity mediated by a defect in dendritic cell stimulatory and T-cell responsive capacities. In contrast, MMP-9-/- recipients showed increased T-cell alloreactivity mediated by a significant increased in dendritic cell stimulatory and T-cell responsive capacities. These results indicate that MMP2 and MMP-9 play significantly different roles in the process of cardiac allograft rejection.

Animals↗