Angelo M de Mattos

University of California, Davis, Davis, California, United States

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Publications (47)169.78 Total impact

  • No preview · Article · Feb 2014 · Journal of Surgical Research
  • [Show abstract] [Hide abstract] ABSTRACT: Objectives/HypothesisLaryngeal transplantation offers the potential for patients without a larynx to recover their voice, which is critical in our communication age. We report clinical and functional outcomes from a laryngotracheal transplant. Widespread adoption of this technique has been slowed due to the ethical concerns of life-long immunosuppression after a nonvital organ transplant. Our patient was already on immunosuppressive medication from prior kidney-pancreas transplantation, and therefore was not exposed to added long-term risk. We describe the unique technical advances, clinical course, and rehabilitation of this patient and the implications for future laryngeal transplantation. Study DesignCase report. MethodsA laryngotracheal transplantation was performed in a 51-year-old prior kidney-pancreas transplant recipient presenting with complete laryngotracheal stenosis. Surgical modifications were made in the previously described technique related to retrieval, vascular supply, and reinnervation. This resulted in a robustly vascularized organ with well-perfused long-segment tracheal transplant and early return of motor reinnervation. ResultsA multidisciplinary approach resulted in a successful transplant without evidence of rejection to date. Postoperatively, the patient continues to rely on a tracheotomy but has had the return of an oral and nasal airway, vocalization, smell, and taste, all experienced for the first time in 11 years. Conclusions We have demonstrated that our methods may result in a successful laryngotracheal transplant. We describe the preparation, surgical technique, rehabilitation, and interventions employed in achieving optimal outcomes. This report contributes valuable information on this rarely performed composite transplant. Laryngoscope, 123:2502-2508, 2013
    No preview · Article · Mar 2013 · The Laryngoscope
  • D. B. Adey · B. Gallay · R. Perez · A. de Mattos
    No preview · Article · Nov 2012 · Transplantation
  • [Show abstract] [Hide abstract] ABSTRACT: Background: In December 2010, a case of West Nile virus (WNV) encephalitis occurring in a kidney recipient shortly after organ transplantation was identified. Methods: A public health investigation was initiated to determine the likely route of transmission, detect potential WNV infections among recipients from the same organ donor, and remove any potentially infected blood products or tissues. Available serum, cerebrospinal fluid, and urine samples from the organ donor and recipients were tested for WNV infection by nucleic acid testing and serology. Results: Two additional recipients from the same organ donor were identified, their clinical and exposure histories were reviewed, and samples were obtained. WNV RNA was retrospectively detected in the organ donor's serum. After transplantation, the left kidney recipient had serologic and molecular evidence of WNV infection and the right kidney recipient had prolonged but clinically inapparent WNV viremia. The liver recipient showed no clinical signs of infection but had flavivirus IgG antibodies; however, insufficient samples were available to determine the timing of infection. No remaining infectious products or tissues were identified. Conclusions: Clinicians should suspect WNV as a cause of encephalitis in organ transplant recipients and report cases to public health departments for prompt investigation of the source of infection. Increased use of molecular testing and retaining pretransplantation sera may improve the ability to detect and diagnose transplant-associated WNV infection in organ transplant recipients.
    No preview · Conference Paper · Oct 2011
  • [Show abstract] [Hide abstract] ABSTRACT: Fatty acids and their eicosanoid metabolites have been shown to be important mediators of the immune response in transplantation. We hypothesize that elevated pretransplant free fatty acids (FFA) levels may be associated with prolonged survival of kidney transplants. Archived pretransplant sera of 130 patients who received a kidney transplant from 1991 to 1997 were analyzed by gas liquid chromatography for a comprehensive FFA profile. FFA levels were categorized by quartiles, and the association between quartiles of the levels for each free-fatty acid and graft survival was initially screened by serial univariate analyses (Kaplan-Meier). All significant variables (FFAs and transplant-specific risk factors) were entered into a multivariable (Cox regression) model. With > 10 y of follow-up, 68 kidney allografts were lost. Factors associated with decreased graft survival by univariate analysis included delayed graft function (DGF), acute rejection (AR), and cold ischemic time (CIT) > 24 h. High levels of arachidonic and γ-linolenic FFA were associated with higher graft survival rates. By multivariate analysis, only DGF, AR, CIT, and arachidonic acid levels were significant. The odds ratios for graft failure for the highest, third, and second quartiles of the pretransplant level of arachidonic acid, compared with the lowest quartile, were 0.18, 0.32, and 0.64, respectively (P = 0.050, log-rank test). For arachidonic acid the survival benefit appeared to be graded with the highest quartile associated with a greater than 80% reduction of risk of kidney graft failure. Pretransplant level of arachidonic acid was independently associated with higher kidney graft survival rates. Further studies are necessary to identify the underlying mechanisms and to determine whether interventions aimed at increasing pretransplant arachidonic acid levels might prove beneficial for renal transplant outcomes.
    No preview · Article · Dec 2010 · Journal of Surgical Research
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    [Show abstract] [Hide abstract] ABSTRACT: Coronary artery disease (CAD) is the predominant cause of sudden cardiac death in the general population, and sudden cardiac death is the leading cause of mortality in end-stage renal disease (ESRD). QT-interval prolongation is an independent prognosticator in ESRD. We reviewed clinical, electrocardiographic, stress test, and coronary angiography data on ESRD patients evaluated for transplantation at our institution between 2000 and 2004 who underwent coronary angiography. The QT interval was corrected for heart rate and QRS duration (QTc). All-cause mortality data were prospectively collected and verified against the Social Security Death Index database. During 40 +/- 28 months of follow-up, 132 of the 280 (47%) patients died prior to renal transplantation. Patients with a prolonged QTc (39%) had 1-, 3-, and 5-year death-rates of 12%, 36%, and 47%, respectively, vs 8%, 24%, and 36% for those with normal QTc (log-rank P = 0.03). In a multivariate Cox regression model that adjusted for age, gender, diabetes mellitus, myocardial infarction, presence and severity of CAD on angiography, left ventricular (LV) hypertrophy, LV ejection fraction (EF), and multiple other variables, QTc remained to be an independent predictor of survival (hazard ratio [HR]: 1.008, 95% confidence interval [CI]: 1.001-1.014, P = 0.016). Female gender, decreasing LVEF, and decreasing severity of CAD on angiography were independent predictors of prolonged QTc. QTc prolongation is an independent predictor of mortality in ESRD patients being evaluated for renal transplantation. The prognostic information gained from the QTc is additive to that provided by the LVEF and the severity of CAD.
    Full-text · Article · Jun 2010 · Clinical Cardiology
  • A C Baker · A de Mattos · S Watkins · B German · C Troppmann · R Perez
    No preview · Article · Feb 2010 · Journal of Surgical Research
  • Christoph Troppmann · Stuart Cohen · Angelo de Mattos · Richard Perez
    No preview · Article · Feb 2010 · Transplantation
    [Show abstract] [Hide abstract] ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    No preview · Article · Jan 2010 · ChemInform
  • [Show abstract] [Hide abstract] ABSTRACT: This study examined the relation between heart rate (HR) response to adenosine and outcome in patients with end-stage renal disease (ESRD). The usual HR increase during adenosine infusion was caused by direct sympathetic stimulation. It was hypothesized that a blunted HR response, which was probably caused by sympathetic denervation, would be associated with a worse outcome in patients with ESRD. One hundred thirty-nine patients with ESRD being evaluated for renal transplantation who underwent coronary angiography and adenosine gated single-photon emission computed tomographic myocardial perfusion imaging were followed up for all-cause mortality. Percentage of change in HR (%DeltaHR) was calculated as [(peak HR during adenosine infusion - HR at rest)/HR at rest] * 100. A control group of 54 patients (normal renal function and no diabetes) was included for comparison of HR responses. Mean age of patients was 54 +/- 9 years, 30% were women, and 68% had type-2 diabetes mellitus. %DeltaHR was 19.2 +/- 18% in patients with ESRD versus 33 +/- 25% in the control group (p <0.0001). At a mean follow-up of 3.4 +/- 1.5 years, 50 patients (36%) with ESRD died. %DeltaHR was lower in nonsurvivors than survivors (12.6 +/- 14% vs 23 +/- 19%; p = 0.0017). Patients with %DeltaHR less than the median value were more likely to have lower left ventricular ejection fraction and larger end-diastolic volume (p <0.05 for each). In a multivariate logistic regression model, %DeltaHR alone was an independent predictor of all-cause mortality (adjusted odds ratio 5.5, 95% confidence interval 2.3 to 12.9, p = 0.0001). In conclusion, patients with ESRD had a blunted HR response to adenosine, and degree of blunting was strongly associated with all-cause mortality.
    No preview · Article · Apr 2009 · The American journal of cardiology
  • No preview · Conference Paper · Jan 2009
  • No preview · Conference Paper · Jan 2009
  • [Show abstract] [Hide abstract] ABSTRACT: Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. This study examined the prognostic power of stress myocardial perfusion imaging (MPI) in 150 patients with ESRD (mean age 53 +/- 9 years; 30% women; 66% with diabetes mellitus) being evaluated for renal transplantation with known coronary anatomy using angiography. Baseline data in addition to perfusion and angiographic parameters were compared between survivors and nonsurvivors. All-cause mortality was defined as the outcome measure. An abnormal MPI result was present in 85% of patients, 30% had left ventricular (LV) ejection fraction (EF) < or =40%, and 40% had multivessel coronary artery disease using angiography. At a mean follow-up of 3.4 +/- 1.5 years, 53 patients died (35%). LVEF < or =40%, LV dilatation (LV end-diastolic volume >90 ml), and diabetes mellitus were associated with higher mortality (all p <0.05). Both total perfusion defect size and mean number of narrowed coronary arteries using angiography were significantly higher in those who died (p <0.05). In a multivariate model, abnormal MPI results (low LVEF or abnormal perfusion) and diabetes alone were independent predictors of death, whereas number of narrowed arteries using coronary angiography was not. Thus, MPI was a strong predictor of all-cause mortality in patients with ESRD. In conclusion, abnormal MPI results independently predicted worse survival and provided more powerful prognostic data than coronary angiography.
    No preview · Article · Jan 2009 · The American journal of cardiology
  • [Show abstract] [Hide abstract] ABSTRACT: Cardiovascular events (CVE) are the leading cause of mortality in kidney transplant recipients. The adverse effects of long-term therapy with steroids on cardiovascular risk have motivated increasing interest in steroid withdrawal (SW). The objective of this study was to compare the incidences of CVE and all-cause mortality between patients who had undergone SW at 1 year posttransplant and control patients who continued on steroids. A cohort of 400 consecutive adult recipients of a kidney transplant between 1993 and 1998 who qualified for late SW was studied. At 1 year posttransplant 188 patients underwent SW, whereas 212 patients continued on steroids. Cox proportional-hazards analysis was used to estimate CVE (cardiac and cerebrovascular events) and all-cause mortality hazard ratios (HR) for patients who had undergone SW versus controls who continued on steroids beyond 1 year. The average follow-up was 61 months. There were 44 (11%) cardiac events, 18 (4.5%) cerebrovascular events, and 41 deaths (10.3%). The composite outcome of CVE and all-cause mortality was reached in 26 (13.8%) subjects who had undergone SW and 50 (23.6%) controls (P=0.013). In adjusted analyses, SW was associated with decreased risk for the composite outcome (HR 0.46, 95% confidence interval [CI] 0.28-0.76), cardiac events (HR 0.48, 95% CI 0.28-0.84), and all-cause mortality (HR 0.27, 95% CI 0.12-0.59). There was no association of SW with the risk for cerebrovascular events (HR 1.76, 95% CI 0.45-7.01). In this retrospective analysis, SW at 1 year posttransplant was associated with decreased risk for future CVE and all-cause mortality.
    No preview · Article · Jan 2009 · Transplantation
  • M Arnol · A M. de Mattos · J S. Chung · J C. Prather · A Mittalhenkle · D J. Norman
    No preview · Article · Jul 2008 · Transplantation
  • No preview · Article · Jul 2008 · Journal of Nuclear Cardiology
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    [Show abstract] [Hide abstract] ABSTRACT: Individuals waiting for a renal transplant experience excessive cardiovascular mortality, which is not fully explained by the prevalence of ischemic heart disease in this population. Overt heart failure is known to increase the mortality of patients with ESRD, but the impact of lesser degrees of ventricular systolic dysfunction is unknown. For examination of the association between left ventricular ejection fraction(LVEF) and mortality of renal transplant candidates, the records of 2718 patients evaluated for transplantation at one institution were reviewed. During 6355 patient-years (median 27 mo) of follow-up, 681 deaths occurred. Patients with systolic dysfunction (LVEF <or= 0.40) had significantly lower survival than those with higher systolic function (median 49 +/- 3.1 versus 72 +/- 4.0 mo; P 0.001) but had similar survival to patients with ischemia (48 +/- 2.5 mo). Multivariate modeling showed that those with systolic dysfunction were nearly twice as likely to die as those with normal systolic function, adjusted for risk factors including diabetes, left ventricular hypertrophy, and ischemia (adjusted hazard ratio 1.7; 95%confidence interval 1.43 to 2.07). In addition, a graded, reverse association between LVEF and mortality was identified. In conclusion, systolic dysfunction is strongly associated with mortality, in a graded manner, in renal transplant candidates.
    Preview · Article · Jun 2008 · Journal of the American Society of Nephrology
  • [Show abstract] [Hide abstract] ABSTRACT: Gated single photon emission computed tomography (SPECT) provides information on myocardial perfusion and left ventricular ejection fraction (LVEF), which correlates with risk of cardiac events in patients with known or suspected coronary artery disease (CAD). We hypothesize that decreased LVEF at time of renal transplant evaluation is an independent risk factor for cardiac death and nonfatal events after transplant. A total of 653 recipients of renal allografts between 1998 and 2005 had stress SPECT imaging before transplantation. One hundred and nineteen (18%) patients had left ventricular (LV) systolic dysfunction (LVEF </=45%). The patients with LV dysfunction differed from the patients with normal LVEF having a higher proportion of males, smokers, left ventricular hypertrophy, previous left heart catheterization, and higher exposure to dialysis. During a mean follow-up of 3.01+/-1.86 years postrenal transplant, 66 patients died and 67 additional patients experienced at least one nonfatal cardiac-related complication. Patients with LV systolic dysfunction were at considerably higher risk for cardiac complications (hazard ratio [HR] 1.8, P=0.01) and all-cause mortality (HR 2.0, P=0.01) after transplantation. By multivariate analysis, LV systolic dysfunction was associated with a 5-fold increase in the cardiac mortality risk, a 2-fold increase in all-cause mortality risk, and a 70% increase in posttransplant cardiac complications. Systolic dysfunction is associated with increased risk for overall and cardiac-related death and nonfatal events after renal transplantation, an association independent of ischemic disease.
    No preview · Article · Dec 2007 · Transplantation
  • [Show abstract] [Hide abstract] ABSTRACT: Cardiovascular disease is the major cause of mortality in patients with end-stage renal disease (ESRD). This study examined the all-cause mortality in 3,698 patients with ESRD evaluated for kidney transplantation at our institution from 2001 to 2004. Mean age for the cohort was 48+/-12 years, and 42% were women. Stress myocardial perfusion imaging was done in 2,207 patients (60%) and coronary angiography in 260 patients (7%). There were 622 deaths (17%) during a mean follow-up period of 30+/-15 months. The presence and severity of coronary disease on angiography was not predictive of survival. Coronary revascularization did not impact survival (p=0.6) except in patients with 3-vessel disease (p=0.05). The best predictor of death was left ventricular ejection fraction, measured by gated myocardial perfusion imaging, with 2.7% mortality increase for each 1% ejection fraction decrease. In conclusion, left ventricular ejection fraction is a strong predictor of survival in patients with ESRD awaiting renal transplantation. Strategies to improve cardiac function or earlier renal transplantation deserve further studies.
    No preview · Article · Oct 2007 · The American Journal of Cardiology
  • A M de Mattos · J Prather · AJ Olyaei · Y Shibagaki · D S Keith · M Mori · D J Norman · T Becker
    [Show abstract] [Hide abstract] ABSTRACT: Cardiovascular mortality is increased in transplant recipients. However, studies including non-fatal events are critical to assess the burden of disease and to identify novel risk factors. We described the incidence of fatal and non-fatal events, and explored associations and interactions among traditional and transplant-specific risk factors and cardiovascular events (CVE) in a cohort of 922 patients transplanted between 1993 and 1998. One hundred and seventy-six patients experienced 201 CVE (111 cardiac, 48 cerebrovascular, 42 peripheral-vascular). Most CVE were non-fatal. Factors associated with cardiac events were (adjusted hazard ratios) tobacco (3.53; P<0.001), obesity (2.92; P<0.001), diabetes (2.63; P<0.001), multiple rejections (2.19; P=0.008), prior CVE (2.0; P=0.004), dialysis >1 year (1.91; P=0.007), and overweight status (1.68; P=0.04); with cerebrovascular events: diabetes and peritoneal dialysis (11.95; P<0.001), age >45 (6.77; P<0.001), diabetes (4.87; P<0.001), prior CVE (3.73; P<0.001), creatinine >141 micromol/l (3.16; P=0.001), peritoneal dialysis (3.06; P=0.027), and obesity (0.32; P=0.046); with peripheral-vascular events: diabetes (8.48; P<0.001), tobacco and cytomegalovirus (3.88; P<0.001), age >45 (2.31; P=0.019), and prior CVE (2.25; P=0.016); with mortality: tobacco and deceased-donor (3.52; P<0.001), age >45 (1.81; P=0.002), diabetes (1.76; P=0.002), pulse pressure (1.64; P=0.029), prior CVE (1.52; P=0.04), and dialysis >1 year (1.47; P=0.04). The majority of CVE post-transplant were non-fatal. Previous CVE was strongly associated with CVE post-transplant. Interactions among transplant-specific and traditional risks impacted significantly the incidence of CVE. Modifiable factors such as duration of dialysis, deceased-donor transplantation, and acute rejection should be viewed as cardiovascular risks.
    No preview · Article · Sep 2006 · Kidney International