Papers by Mani Daneshmand
Surgery, 2004
Although internal thoracic arteries (ITAs) and radial arteries (RAs) have been shown to have simi... more Although internal thoracic arteries (ITAs) and radial arteries (RAs) have been shown to have similar patency, RAs tend to be more vasospastic postoperatively compared with ITAs. Therefore, the purpose of this study was to examine the effect of histamine subclass 1 (H1) receptors and histamine subclass 2 (H2) receptors on vasoreactivity in human ITAs and RAs. Vessels were obtained from coronary artery bypass grafting patients. Human arterial rings (2 mm) were mounted in tissue baths, and baseline contractility was determined. Histamine concentration response curves (10(-9)-10(-3) mol/L) were performed in the absence or presence of diphenhydramine (H1 antagonist, 10(-4) mol/L) or famotidine (H2 antagonist, 10(-4) mol/L). Comparison of curves was performed by 2-way analysis of variance with repeated measures and a Bonferroni post-t test. Maximal contraction to histamine was significantly greater in RA (8.3 +/- 0.8 g, n = 6) than in ITA (2.9 +/- 0.3, n = 6), (P < .05). However, there...
American journal of physiology. Cell physiology, 2004
The preferential association of cholesterol and sphingolipids within plasma membranes forms organ... more The preferential association of cholesterol and sphingolipids within plasma membranes forms organized compartments termed lipid rafts. Addition of caveolin proteins to this lipid milieu induces the formation of specialized invaginated plasma membrane structures called caveolae. Both lipid rafts and caveolae are purported to function in vesicular transport and cell signaling. We and others have shown that disassembly of rafts and caveolae through depletion of plasma membrane cholesterol mitigates mechanotransduction processes in endothelial cells. Because osteoblasts are subjected to fluid-mechanical forces, we hypothesize that cholesterol-rich plasma membrane microdomains also serve the mechanotransduction process in this cell type. Cultured human fetal osteoblasts were subjected to either sustained hydrostatic pressure or laminar shear stress using a pressure column or parallel-plate apparatus, respectively. We found that sustained hydrostatic pressure induced protein tyrosine phos...
Our goal was to investigate whether left ventricular (LV) diastolic dysfunction was an important ... more Our goal was to investigate whether left ventricular (LV) diastolic dysfunction was an important pathophysiological mechanism underlying the initiation of new-onset post-operative atrial fibrillation (POAF).
Circulation, Jan 17, 2015
The aims of this study were to review the principles underlying use of the Carpentier-McCarthy-Ad... more The aims of this study were to review the principles underlying use of the Carpentier-McCarthy-Adams IMR ETlogix ® asymmetric annuloplasty ring for the treatment of chronic ischemic mitral regurgitation and to report medium-term clinical outcomes observed at our center. The in-hospital mortality rate was 2.8%. Echocardiography at hospital discharge confirmed the absence of mitral regurgitation in 88.8% of patients. Patients underwent clinical and echocardiographic followup (median duration, 23 months; range, 12-44 months). Late follow-up echocardiography demonstrated the recurrence of moderate mitral regurgitation in 5.7% of patients and of moderate-to-severe mitral regurgitation in 2.9%. The rate of survival free from recurrence of ≥grade-2 mitral regurgitation was 95.2% at 15 months and 88.9% at 25 months. Mitral valve repair using the asymmetric Carpentier-McCarthy-Adams IMR ETlogix ® ring in patients with chronic ischemic mitral regurgitation enabled regurgitation to be effectively corrected by producing asymmetric changes in the morphology of the mitral ring. Medium-term outcomes, with regard to the degree of mitral valve competence, were excellent.
ABSTRACT Advanced heart failure (HF) patients (pts) with a high central venous pressure (CVP)/pul... more ABSTRACT Advanced heart failure (HF) patients (pts) with a high central venous pressure (CVP)/pulmonary capillary wedge pressure (PCWP) ratio are at risk for right ventricular failure (RVF) after left ventricular assist device (LVAD) placement. The incidence of this RVF predictor in ambulatory pts with advanced HF and the associated outcomes are unknown. We investigated the “RVF biomarker” of CVP/PCWP≥0.63 in ambulatory HF pts.Methods and MaterialsWe analyzed 188 consecutive INTERMACS 4-5 pts evaluated in the Duke HF Clinic (2005-2010) who had a right heart catheterization and cardiopulmonary exercise test (CPX) within 90-days. Pts were stratified by CVP/PCWP ≥ or &lt;0.63. Pt characteristics, Seattle HF Model (SHFM) score and outcomes (survival free of LVAD/transplant/death) were evaluated.Results51 pts (27%) had a ratio ≥0.63. The groups were similar with respect to race, gender, HF etiology, and HF medications (all P&gt;0.05). Diuretic dose, ejection fraction and natriuretic peptide levels were similar. There was a trend toward worse CPX variables in pts ≥0.63 [peak VO2 10.7 mL/kg/min (8.7-13.6) vs. 11.7 (9.5-14.0), P=0.12; VE-VCO2 slope 46 (36-50) vs. 39 (34-49), P=0.056]. Predicted 1 yr survival by SHFM was lower in pts ≥0.63 [88% vs. 93%, P=0.03]. Over a median follow-up of 264 days, observed outcomes were similar between groups (Figure).Conclusions Despite the belief that INTERMACS 4-5 pts may be “too well” for an LVAD, we found that &gt;25% of these pts already displayed a marker for post-LVAD RVF. In pts with a CVP/PCWP≥0.63, outcomes in the context of contemporary advanced HF therapies were similar vs. pts &lt;0.63 despite worse predicted survival by the SHFM.
Despite advances in medical therapy for chronic heart failure (HF), advanced HF carries a dismal ... more Despite advances in medical therapy for chronic heart failure (HF), advanced HF carries a dismal prognosis. Options such as transplantation and durable mechanical circulatory support have greatly improved outcomes for these patients, but their introduction has introduced significant complexity to patient management. Although much of this management occurs at specialized heart transplant centers, it is the responsibility of the primary cardiologist of the patient with advanced HF to refer patients at the appropriate time and to help them navigate the difficult decisions related to the pursuit of advanced therapies. We present a unique pathway that incorporates guidelines, recent data, and expert opinion to help general cardiologists determine which patients should be referred for transplantation or durable mechanical circulatory support, and when they should be referred. Decision making on referral to the heart transplant center is also summarized.
Detailed analyses of risk-adjusted outcomes after mitral valve surgery have documented significan... more Detailed analyses of risk-adjusted outcomes after mitral valve surgery have documented significant survival decrements with tissue valves at any age. Several recent studies of prosthetic aortic valve replacement (AVR) also have suggested a poorer performance of tissue valves, although analyses have been limited to small matched series. The study aim was to test the hypothesis that AVR with tissue valves is associated with a lower risk-adjusted survival, as compared to mechanical valves. Between 1986 and 2009, primary isolated AVR, with or without coronary artery bypass grafting (CABG), was performed with currently available valve types in 2148 patients (1108 tissue valves, 1040 mechanical). Patients were selected for tissue valves to be used primarily in the elderly. Baseline and operative characteristics were documented prospectively with a consistent variable set over the entire 23-year period. Follow up was obtained with mailed questionnaires, supplemented by National Death Index searches. The average time to death or follow up was seven years, and follow up for survival was 96.2% complete. Risk-adjusted survival characteristics for the two groups were evaluated using a Cox proportional hazards model with stepwise selection of candidate variables. Differences in baseline characteristics between groups were (tissue versus mechanical): median age 73 versus 61 years; non-elective surgery 32% versus 28%; CABG 45% versus 35%; median ejection fraction 55% versus 55%; renal failure 6% versus 1%; diabetes 18% versus 7% (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Unadjusted Kaplan-Meier survival was significantly lower with tissue than mechanical valves; however, after risk adjustment for the adverse profiles of tissue valve patients, no significant difference was observed in survival after tissue or mechanical AVR. Thus, the hypothesis did not hold, and risk-adjusted survival was equivalent, of course qualified by the fact that selection bias was evident. With selection criteria that employed tissue AVR more frequently in elderly patients, tissue and mechanical valves achieved similar survival characteristics across the spectrum of patient risk. Further studies of the relative outcomes of mechanical versus tissue valves across the spectrum of patient age seem indicated.
As the duration of support increases for patients with continuous flow left ventricular assist de... more As the duration of support increases for patients with continuous flow left ventricular assist devices (LVADs), device replacement may still be necessary for a variety of indications. Outcomes after replacement LVAD surgeries have not been extensively described, and whether these patients experience outcomes similar to primary LVAD implant patients remains unclear. From 2003 to 2012, 342 consecutive implantable LVAD procedures took place at a single institution, of which 201 were considered destination therapy. Within this larger group, 30 patients underwent 35 replacement procedures. The three major indications for replacement LVAD procedures were mechanical/electrical failure (57%), hemolysis/thrombosis (29%), and infection (14%). Propensity matching using preoperative characteristics was used to generate a primary implant control group to determine the impact of the replacement status on outcomes. Thirty-day and 1-year survival after LVAD replacement was 90% and 48%, respectively. Survival outcomes were worse for patients undergoing device replacement compared with the matched primary cohort (p = 0.03). The need for transfusion and the incidence of postoperative right ventricular and renal dysfunction were similar between the two groups, as was length of hospitalization. There was no difference between the rates of postoperative infection or stroke. Emergent replacement procedures had a higher mortality than those done nonemergently. Given these findings, earlier timing for replacement, temporary stabilization with an extracorporeal device, and use of a nonsternotomy surgical approach should be investigated as strategies to improve outcomes.
Journal of vascular surgery, 2004
Emergent repair of ruptured abdominal aortic aneurysms (rAAAs) is associated with high perioperat... more Emergent repair of ruptured abdominal aortic aneurysms (rAAAs) is associated with high perioperative morbidity and mortality. One of the significant complications of this surgery is bowel ischemia. Reports detail mortality as high as 80% when this condition is realized. The objective of this project was to determine both the incidence and the effect of mandatory postoperative colonoscopy on outcome of colon ischemia after rAAA. From July 1995 to September 2002 all patients with an rAAA who underwent emergent aortic reconstruction were included in this review. All colonoscopies were performed within 48 hours, ischemia was graded consistently, and treatment was initiated per protocol based on grade of ischemia. Patients with grades I and II ischemia were followed up with medical management and repeat colonoscopy. All patients with grade III ischemia underwent bowel resection. Preoperative, intraoperative, and postoperative variables were collected to assess possible independent risk f...
Uploads
Papers by Mani Daneshmand