PubMed Health⌕ Search

Biomedical subjects

Vivek Rao

Publications and source records attributed to Vivek Rao.

At least 37 records · Page 2Linked to original sources
PubMed2005

Elicitation of efficient, protective immune responses by using DNA vaccines against tuberculosis.

DNA vaccination is an effective method for elicitation of strong humoral as well as cellular immune responses. DNA vaccines expressing mycobacterial antigens ESAT-6 (Rv3875), alpha-crystallin (Rv2031c) and superoxide dismutase A (Rv3846) were evaluated for their immune responses in Balb/c mice and protective efficacy in guinea pigs. Immunization of mice with the DNA vaccines expressing superoxide dismutase A and alpha-crystallin resulted in markedly higher levels of IFN-gamma as compared to the levels of IL-10. The DNA vaccine expressing ESAT-6 elicited a mixed Th1/Th2 response. Immunization of guinea pigs with these DNA vaccines and subsequent challenge of animals with Mycobacterium tuberculosis H(37)Rv, showed that DNA vaccine expressing superoxide dismutase imparted the maximum protection as observed by a 50 and 10 folds reduction in bacillary load in spleens and lungs, respectively, in comparison to immunization with vector control.

Animals↗
PubMed2005

Tetrahydrobiopterin prevents cyclosporine-induced vasomotor dysfunction.

BACKGROUND: Cyclosporine A (CsA) is associated with negative side effects such as endothelial injury, which may lead to transplant vasculopathy. CsA can impair nitric oxide (NO) homeostasis. Therefore, tetrahydrobiopterin (BH4), a NO synthase cofactor, may limit endothelial injury by improving NO production. Our study examines the effect of CsA and BH4 exposure on endothelial function. METHODS: Lewis rats were injected with CsA, BH4, CsA+BH4, or saline intraperitoneally daily for 2 weeks. With use of a small vessel myograph, thoracic aortic segments were assessed for endothelial-dependent (Edep) and independent relaxation after exposure to acetylcholine and sodium nitroprusside. Sensitivity to vasospasm was evaluated after exposure to endothelin (ET)-1. RESULTS: CsA exposure resulted in impaired Edep vasorelaxation compared with control (P=0.01). BH4 attenuated the deleterious effects of CsA. Compared with control, all treatment groups demonstrated significantly increased sensitivity to ET-1. Furthermore, endothelial nitric oxide synthase expression in the thoracic aorta was reduced after CsA treatment, and this reduction was attenuated by BH4 therapy (P<0.01). ETA receptor expression in the aorta was increased after CsA treatment, but BH4 treatment prevented CsA-induced ETA over-expression (P=0.004). However, ETB receptor expression was increased by BH4 treatment compared with CsA and control (P=0.02). CONCLUSION: Our findings suggest that CsA-induced vasomotor dysfunction is a result of alterations in both NO and ET-1 regulation and that BH4 may prevent the deleterious effects of CsA. However, the beneficial effects of BH4 are associated with increased sensitivity to ET-1. Therefore, a combination of BH4 and ET-1 blockade may prove to be an ideal combination for preservation of endothelial function.

Animals↗
PubMed2005

Tetrahydrobiopterin deficiency exaggerates intimal hyperplasia after vascular injury.

Decreased levels of tetrahydrobiopterin (BH4), an absolute cofactor for nitric oxide synthase (NOS), lead to uncoupling of NOS into a superoxide v. nitric oxide producing enzyme, and it is this uncoupling that links it to the development of vascular disease. However, the effects of in vivo deficiency of BH4 on neointimal formation after vascular injury have not been previously investigated. Hph-1 mice, which display 90% deficiency in guanine triphosphate cyclohydrolase I, the rate limiting enzyme in BH4 synthesis, were used. Hph-1 and wild-type mice, treated with either vehicle or BH4 (n = 15 per group), were subjected to wire-induced femoral artery injury, and NOS expression and activity, inflammation, cell proliferation, superoxide production, and neointimal formation were assessed. The major form of NOS expressed over vessel wall after vascular injury was endothelial NOS. Hph-1 mice exhibited lower NOS activity (2.8 +/- 0.3 vs. 4.5 +/- 0.4 pmol/min/mg protein, P < 0.01), and higher aortic superoxide content (5.2 +/- 2.0 x 10(5) cpm vs. 1.6 +/- 0.7 x 10(5) cpm, P < 0.01) compared with wild-type controls, indicating uncoupling of NOS. Treatment of hph-1 mice with BH4 significantly increased NOS activity (from 2.8 +/- 0.3 to 4.1 +/- 0.4 pmol.min(-1).mg protein(-1), P < 0.05), and attenuated superoxide production (from 5.2 +/- 2.0 x 10(5) cpm to 0.8 +/- 0.7 x 10(5) cpm, P < 0.05). Hph-1 mice also had higher inflammatory reactions and more cell proliferation after vascular injury. Furthermore, hph-1 mice responded by a marked increase in neointimal formation at 4 wk after vascular injury, compared with wild-type controls (intima:media ratio: 4.5 +/- 0.5 vs. wild-type 0.7 +/- 0.1, P < 0.001). Treatment of hph-1 mice with BH4 prevented vascular injury-induced increase in neointimal formation (intima:media ratio: 1.4 +/- 0.1 vs. hph-1, P < 0.001). Treatment had no effect on wild-type controls. In summary, we describe, for the first time, that in vivo BH4 deficiency facilitates neointimal formation after vascular injury. Modulation of BH4 bioavailability is an important therapeutic target for restenosis.

Animals↗
PubMed2005

Mycobacterium tuberculosis controls host innate immune activation through cyclopropane modification of a glycolipid effector molecule.

Mycobacterium tuberculosis (Mtb) infection remains a global health crisis. Recent genetic evidence implicates specific cell envelope lipids in Mtb pathogenesis, but it is unclear whether these cell envelope compounds affect pathogenesis through a structural role in the cell wall or as pathogenesis effectors that interact directly with host cells. Here we show that cyclopropane modification of the Mtb cell envelope glycolipid trehalose dimycolate (TDM) is critical for Mtb growth during the first week of infection in mice. In addition, TDM modification by the cyclopropane synthase pcaA was both necessary and sufficient for proinflammatory activation of macrophages during early infection. Purified TDM isolated from a cyclopropane-deficient pcaA mutant was hypoinflammatory for macrophages and induced less severe granulomatous inflammation in mice, demonstrating that the fine structure of this glycolipid was critical to its proinflammatory activity. These results established the fine structure of lipids contained in the Mtb cell envelope as direct effectors of pathogenesis and identified temporal control of host immune activation through cyclopropane modification of TDM as a critical pathogenic strategy of Mtb.

Animals↗
PubMed2005

Stentless aortic valves are hemodynamically superior to stented valves during mid-term follow-up: a large retrospective study.

BACKGROUND: Several studies have compared left venticular mass (LVM) regression and hemodynamic data for stentless versus stented aortic bioprostheses with conflicting results. The major limitations of these studies are their small sample size and short-term follow-up. We therefore compared midterm LVM regression, hemodynamic data, and survival in a large population of tissue aortic valve replacement (AVR) patients. METHODS: All patients undergoing tissue AVR at our institution between 1998 and 2001 were included (n = 737). Patients were divided into two groups according to type of bioprosthetic implanted: stentless patients (total n = 310) (Toronto SPV [St Jude Medical, St Paul, MN], n = 146 and Freestyle [Medtronic, Minneapolis, MN], n = 164) and stented patients (total n = 427) (Perimount [Edwards Life Sciences Inc, Irvine, CA], n = 291 and Mosaic [Medtronic], n = 136). RESULTS: The two groups of patients had similar preoperative transvalvular gradients and LVM index (130 +/- 47 vs 130 +/- 42 g/m2 for stentless versus stented valves, respectively). Predischarge echos revealed that stentless patients had significantly lower mean transvalvular gradients (11 +/- 5 vs 15 +/- 6 mm Hg, p < 0.001) and larger effective orifice areas (1.32 +/- 0.52 vs 1.22 +/- 0.48 cm2, p = 0.01). Follow-up echocardiograms were obtained in 99% of surviving patients 28 +/- 22 (range, 0-79) months postoperatively. Stentless patients had significantly lower LVM index during follow-up (100 +/- 32 vs 107 +/- 32 g/m2, p = 0.005) and stentless valves were an independent predictor of LVM regression. Furthermore, a higher proportion of stented patients had residual LV hypertrophy during follow-up (28% vs 18%, p = 0.001). Stentless valves were associated with improved midterm survival by univariate analysis, but not by multivariable analysis. CONCLUSIONS: Midterm follow-up in a large number of patients reveals that stentless bioprostheses are hemodynamically superior to stented valves.

Aged↗
PubMed2005

Use of basiliximab and cyclosporine in heart transplant patients with pre-operative renal dysfunction.

BACKGROUND: The combined use of basiliximab and cyclosporine in heart transplantation is under investigation. In this study we sought to evaluate the safety and efficacy of basiliximab and delayed initiation of cyclosporine in patients with renal dysfunction undergoing heart transplantation. METHODS: Seven patients (Group A) with renal dysfunction (creatinine > or =200 micromol/liter) received induction therapy with basiliximab. Seven patients (Group B) with renal dysfunction comprised the control group and received induction therapy with rabbit anti-thymocyte serum. Cyclosporine was initiated 5 days post-transplant in Group A and within 5 days post-transplant in Group B. RESULTS: All patients were alive at the end of the 6-month follow-up. In Group A, mean pre-transplant creatinine was 243 +/- 48 micromol/liter, at 1 week post-transplant was 180 +/- 39 micromol/liter (p = 0.02), at 1 month was 166 +/- 57 micromol/liter (p = 0.019), at 3 months was 182 +/- 25 micromol/liter (p = 0.01) and at 6 months was 179 +/- 45 micromol/liter (p = 0.024). In Group B, mean pre-transplant creatinine was 242 +/- 41 micromol/liter, at 1 week was 140 +/- 35 micromol/liter (p = 0.0003), at 1 month was 143 +/- 38 mumol/liter (p = 0.0005), at 3 months was 138 +/- 37 micromol/liter (p = 0.0003) and at 6 months was 154 +/- 30 micromol/liter (p = 0.0006). There were no differences in renal dysfunction between both groups at 1 week (p = 0.069), 1 month (p = 0.39) or 6 months (p = 0.24) post-HT. Fewer episodes of cellular rejection were identified in Group B within the 6-month follow-up period. CONCLUSIONS: The use of induction therapy either with basiliximab or rabbit anti-thymocyte serum in patients with pre-operative renal dysfunction confers renal protection early and up to 6 months post-transplant. Delayed initiation of cyclosporine might be considered to provide additional renal protection.

Adult↗
PubMed2005

Monitoring of cyclosporine 2-hour post-dose levels in heart transplantation: improvement in clinical outcomes.

BACKGROUND: Cyclosporine 2-hour post-dose (C2) monitoring is predictive of outcomes in solid-organ transplants. The purpose of this study was to determine C2 levels at various time points after heart transplantation and determine whether trough (C0) or C2 better predicts clinical outcomes. METHODS: This was a 2-phase prospective study with paired determinations of cyclosporine levels at C0 and C2 in 58 heart transplant patients (46 men; mean age, 56 years). Phase I (6-month follow-up): cyclosporine monitored according to C0 levels (C2 blinded). Phase II (6-month follow-up): cyclosporine monitored according to C2 levels (C0 blinded). Clinical outcomes assessed were severe infections, rejection score, and renal dysfunction. RESULTS: No differences were observed in renal function between the phases. In Phase I, 8 infections (4 severe) and in Phase II, 6 infections (2 severe) were detected. During Phase I, the C0 levels did not correlate (p = .96) with the presence (195 +/- 121 ng/ml) or not (197 +/- 100 ng/ml) of rejection. During Phase II, C0 levels did not correlate (p = .88) with the presence (204 +/- 85 ng/ml) or not (209 +/- 138 ng/ml) of rejection. During Phase I, C2 levels did correlate (p = 0.022) with the presence (777 +/- 326 ng/ml) or not (1,015 +/- 422 ng/ml) of rejection. During Phase II, higher C2 levels showed a significant correlation (p = 0.03) with no rejection (967 +/- 470 ng/ml vs 765 +/- 297 ng/ml, no rejection vs rejection, respectively). CONCLUSION: High C2 levels were associated with less episodes of acute cellular rejection in patients post-heart transplantation. Monitoring with C2 levels is feasible and safe in terms of preservation of renal function and infection rates.

Adult↗
PubMed2005

Cardiac allograft preservation using donor-shed blood supplemented with L-arginine.

BACKGROUND: Despite improved preservation techniques, myocardial and endothelial dysfunction persists after cardiac transplantation. L-arginine has been shown to decrease endothelial injury in several models of ischemia and reperfusion. We assessed the effects of L-arginine on allograft preservation in a porcine model of cardiac transplantation. METHODS: Orthotopic cardiac transplants were performed in Yorkshire pigs. Hearts were randomly arrested with high potassium cardioplegia with or without L-arginine at a dose of 2.5 mmol/liter (LARGlow) and 5.0 mmol/liter. Donor-shed blood was collected at the time of organ harvest and intermittently perfused throughout the storage period. Coronary endothelial function was assessed at baseline and after reperfusion by measuring the change in coronary blood flow after exposure to acetylcholine or nitroglycerin. Pressure-volume relationships before and after transplant were evaluated with conductance catheter measurements. Myocardial biopsy specimens were assessed for inflammatory markers of cellular injury. RESULTS: High-dose L-arginine uniformly resulted in ischemic contracture in all hearts, and there was no return of function in any hearts after storage. The low-dose L-arginine group had a greater ability to wean off cardiopulmonary bypass and displayed improved recovery of left ventricular function. Control animals had a 26% reduction in coronary flow compared with 13% for LARGlow. LARGlow resulted in decreased release of inflammatory cytokines compared with control. CONCLUSIONS: Low-dose L-arginine preserves myocardial and endothelial function and decreases endothelial injury when it is used as a supplement to intermittent donor blood perfusion. In contrast, high-dose L-arginine resulted in severe endothelial injury and an inability to recover ventricular function after 5 hours of global ischemia.

Animals↗
PubMed2005

Combined endothelial and myocardial protection by endothelin antagonism enhances transplant allograft preservation.

BACKGROUND: Endothelin is a potent inflammatory peptide associated with myocardial dysfunction, coronary vasculopathy, and reduced survival after cardiac transplantation. We hypothesized that endothelin antagonism during cardiac allograft storage would limit early endothelial dysfunction and improve myocardial performance after transplantation. METHODS: Porcine orthotopic transplantations (n = 16) were performed after 6 hours of ischemic storage. Intermittent donor blood perfusion (control, n = 8) was compared with donor blood perfusion enhanced with 100 micromol/L of an endothelin receptor blocker (n = 8). Left ventricular performance was assessed after caval occlusion with a Millar micromanometer and conductance catheter. Coronary endothelial function was assessed in vitro with a macrovascular tissue bath apparatus. Myocardial endothelin, tumor necrosis factor alpha, and transforming growth factor beta protein expression were determined. Oxidative stress was inferred on the basis of 8-isoprostane levels, and myocardial metabolism was inferred on the basis of the extraction or production of oxygen, acid, and lactate by the heart. RESULTS: Endothelial function was diminished 48 hours after transplantation but not earlier. Endothelin receptor blocker treatment during preservation limited coronary endothelial dysfunction 48 hours after reperfusion ( P = .001). Weaning from cardiopulmonary bypass and left ventricular performance after transplantation was improved in endothelin receptor blocker-treated hearts (P = .02). Myocardial endothelin expression was equivalent in both groups and increased during reperfusion after transplantation (P = .001). Tumor necrosis factor alpha levels decreased with endothelin receptor blocker treatment (P = .02), whereas transforming growth factor beta levels did not change (P = .86). 8-Isoprostane, oxygen, acid, and lactate levels were similar, suggesting that oxidative stress and metabolism were not important mechanisms of benefit. CONCLUSIONS: Endothelin accumulates during allograft storage and contributes to endothelial and myocardial dysfunction after transplantation. Endothelin blockade during allograft preservation limits endothelial injury and enhances ventricular recovery after transplantation.

Animals↗
PubMed2005

Hyperglycemia during cardiopulmonary bypass is an independent risk factor for mortality in patients undergoing cardiac surgery.

BACKGROUND: Hyperglycemia is commonly present in the perioperative period in patients undergoing cardiac surgery, even during administration of insulin. A direct relationship between postoperative hyperglycemia and mortality has been established in diabetic patients undergoing cardiac surgery. However, this relationship might be confounded because patients with poor outcome receive more glucogenic drugs postoperatively. We assessed the influence of hyperglycemia (highest glucose level) during cardiopulmonary bypass on perioperative morbidity and mortality in diabetic and nondiabetic patients. METHODS: We performed a multivariate logistic regression analysis on all diabetic (n = 1579) and nondiabetic (n = 4701) patients undergoing cardiac surgery at the Toronto General Hospital between 1999 and 2001. Boluses of insulin were given during cardiopulmonary bypass when the glucose level exceeded 15 mmol/L, when the serum potassium level exceeded 6.0 mmol/L, or both. RESULTS: Overall mortality was 1.8% (n = 115). A high glucose level during cardiopulmonary bypass was an independent predictor of mortality in both diabetic (odds ratio, 1.20; confidence interval, 1.08-1.32) and nondiabetic (odds ratio, 1.12; confidence interval, 1.06-1.19; per millimole per liter increase in glucose) patients. A high glucose level during cardiopulmonary bypass was also an independent predictor of all major adverse events in both patient groups (odds ratio, 1.06; confidence interval, 1.03-1.09). A high glucose level was not closely related to cardiopulmonary bypass (r = 0.3) or aortic crossclamp times (r = 0.4). CONCLUSIONS: A high peak serum glucose level during cardiopulmonary bypass is an independent risk factor for death and morbidity in diabetic patients and unexpectedly also in nondiabetic patients.

Cardiac Surgical Procedures↗
PubMed2005

Cardiac allograft vasculopathy: a review.

Cardiac allograft vasculopathy (CAV) is a major factor limiting long-term survival after cardiac transplantation. CAV is an accelerated form of coronary artery disease (CAD) that is characterized by concentric fibrous intimal hyperplasia along the length of coronary vessels. Both immunologic and nonimmunologic risk factors contribute to the development of CAV by causing endothelial dysfunction and injury eventually leading to progressive intimal thickening. The diagnosis of CAV remains a challenge as angiography, the standard method for detecting focal plaques, lacks sensitivity in detecting CAV, and intravascular ultrasonography, a more sensitive method, lacks the ability to evaluate the entire coronary tree. The disease is difficult to treat and results in significant morbidity and mortality. Since treatment of CAV is limited and usually involves repeat transplantation, prevention or mitigation of immunologic and nonimmunologic risk factors is critically important. CAV prevention may involve therapy that provides protection against endothelial injury implemented just before transplantation, during storage and transplantation as well as after transplantation. This review addresses the frequency of occurrence, pathophysiology, diagnosis and treatment of CAV, highlighting areas of active research.

Coronary Artery Disease↗
PubMed2004

Novel cardioprotective effects of pravastatin in human ventricular cardiomyocytes subjected to hypoxia and reoxygenation: beneficial effects of statins independent of endothelial cells.

Cardioprotective strategies are needed to prevent perioperative myocardial dysfunction in high-risk patients undergoing cardiac surgery. Despite accumulating evidence that statins exert lipid-independent cardioprotective effects, these have been ascribed primarily to improvements in endothelial function and neutrophil-endothelial interaction. The direct effects of statins on cardiomyocytes (independent of endothelial cells) remain unknown. Using a well-characterized model of low-volume hypoxia and reoxygenation, we studied the effects of pravastatin on human ventricular cardiomyocytes. Cardiomyocytes were subjected to 90 min of low-volume hypoxia and 30 min of reoxygenation in the presence and absence of pravastatin (1, 10, and 100 microm) (n = 10 per group). In some experiments, the effects of endothelin (ET) receptor blockade (with bosentan) and nitric oxide synthase (NOS) inhibition (with L-NAME) on pravastatin-mediated cardioprotection were evaluated. Cell survival, NO, and ET-1 production and protein kinase Akt activation were determined. Pravastatin treatment prevented cardiomyocyte cell death following simulated hypoxia and reoxygenation (P < 0.01). This effect was mediated via an increase in NO release, decrease in myocyte ET-1 production/action, and an increase in protein kinase Akt activation. We demonstrate, for the first time, novel protective effects of pravastatin in human ventricular cardiomyocytes independent of endothelial cells or other cell types. Statin therapy may restore ischemic hearts to full functional integrity during cardioplegic arrest through a direct effect on cardiomyocyte survival.

Acyl Coenzyme A↗
PubMed2004

Bridging to transplant with the HeartMate left ventricular assist device: The Columbia Presbyterian 12-year experience.

OBJECTIVE: Implantation of a left ventricular assist device as a bridge to transplantation has become an acceptable approach for patients with end-stage heart failure. Our long-term results with 3 Thoratec HeartMate devices are presented to outline improvements in successful bridging to transplantation and post-transplant survival. METHODS: From August 1990 through January 2003, 243 patients underwent implantation of Thoratec HeartMate devices as a bridge to transplantation. This included 52 (21.4%) pneumatic devices, 17 (7.0%) dual-lead vented electric devices, and 174 (71.6%) single-lead vented electric devices. RESULTS: Mean age was 49.7 +/- 13.7 years. Mean support time was 78.1 +/- 82.9 days (0-541). Bridging success increased from 63.5% (n = 33) for pneumatic devices to 64.7% (n = 11) for dual-lead vented electric devices and 72.4% (n = 126) for single-lead vented electric devices (P =.005). Posttransplant 1-, 3-, and 5-year actuarial survival increased from 87.5%, 78.1%, and 71.9% in patients with pneumatic devices to 91.5%, 86.9%, and 81.3%, respectively, for patients with single-lead vented electric devices. Device infection and malfunction occurred in 17.7% (n = 43) and 12.8% (n = 31) of patients, respectively. CONCLUSIONS: Successful bridging to transplantation and posttransplant survival has improved over time. Left ventricular assist devices have become increasingly more effective in bridging patients with end-stage heart failure to transplantation. This is likely due to a combination of better patient selection, improvements in clinical practice, and evolution in device design.

Device Removal↗
PubMed2004

Left ventricular reconstruction: Early and late results.

OBJECTIVES: In patients with coronary disease and poor left ventricular function, ventricular reconstruction with revascularization is a surgical option. Details of patient selection and optimal surgical technique are still debated. This study reports results achieved with ventricular reconstruction in 285 patients who had akinesia or dyskinesia associated with relative wall thinning. METHODS: Data were prospectively collected. Reconstruction on the beating heart was accomplished by a modified linear closure plus septoplasty, when indicated, (dyskinetic septum). Preoperatively, 237 (83%) were in symptom class III or IV with congestive heart failure (n =174; 61%), angina (n = 157; 55%), or ventricular tachycardia (n = 107; 38%). Average ejection fraction was 24% +/- 11%, and 144 (51%) had preoperative grade 2+ mitral regurgitation. Operative procedures included coronary artery bypass grafting in 262 (92%), septoplasty in 64 (22%), ablation of ventricular tachycardia in 118 (41%), and a mitral valve procedure in 6 (2%). RESULTS: Operating room mortality was 2.8%. Perioperative support included intra-aortic balloon pumping in 49 (17%) and inotropic drugs in 154 (54%). During a mean follow-up of 63 +/- 48 months, 8 patients required transplantation (interval of 49 +/- 41 months), 2 needed mitral valve replacement, and 9 required use of an implantable cardioverter-defibrillator for ventricular tachycardia. At 1, 5, and 10 years actuarial survivals were 92%, 82%, and 62%. Freedom from sudden death was 99%, 97%, and 94%. Among survivors, symptom class improved in 140 of 208 patients (67%), mean improvement 1.3 +/- 1.1 functional class per patient. Average increase in ejection fraction postoperatively was 10% +/- 9%. CONCLUSIONS: Using wall thinning as a criterion for patient selection, left ventricular reconstruction can be performed with low operative mortality, provides good control of symptoms, excellent long-term survival, and freedom from sudden death. This approach should be considered in all patients with coronary disease, poor left ventricular function, and relative wall thinning.

Adult↗
PubMed2004

Calcium antagonists are associated with reduced mortality after cardiac surgery: a propensity analysis.

OBJECTIVES: Observational studies have questioned the effectiveness of perioperative calcium channel blockers but failed to correct for selection biases. We therefore performed a prospective observational cohort study of the effects of calcium channel blockers on cardiac surgical mortality. A propensity score technique was used for risk adjustment. METHODS: We identified 6619 patients who underwent nontransplant cardiac surgery at the Toronto General Hospital (Toronto, Ontario, Canada) between May 1999 and December 2001. Propensity scores for calcium channel blocker use were constructed for the entire sample and for the subgroup (n = 5222) that underwent coronary artery bypass grafting. The calcium channel blocker adjusted odds ratio for in-hospital mortality after cardiac surgery was determined by using multiple logistic regression and propensity matched-pairs analyses. A subgroup analysis was performed for patients who underwent coronary artery bypass grafting: the calcium channel blocker adjusted odds ratio for mortality was determined by using propensity score matched-pairs analyses. RESULTS: Calcium channel blockers were associated with significantly reduced cardiac surgical mortality after adjustment with both multiple logistic regression (odds ratio, 0.56; 95% confidence interval, 0.33-0.94; P =.028) and propensity score matched-pairs analyses (odds ratio, 0.56; 95% confidence interval, 0.32-0.98; P =.042). Calcium channel blockers were also associated with reduced mortality (odds ratio, 0.48; 95% confidence interval, 0.23-0.98; P =.044) among patients who underwent coronary artery bypass grafting. CONCLUSIONS: After adjustment for baseline differences, calcium channel blockers were associated with significantly reduced mortality after cardiac surgery. This benefit also extends to the subgroup that underwent coronary artery bypass grafting. A large randomized controlled trial of perioperative calcium channel blockers is therefore warranted.

Adrenergic beta-Antagonists↗
PubMed2004

Under-utilization of mechanical circulatory support in Canada: why and what can be done?

In October of 2002, a workshop was held as part of the Canadian Cardiovascular Congress in Edmonton, Canada, entitled "Under-Utilization of Mechanical Circulatory Support in Canada. Why and What Can Be Done?" The workshop examined various issues related to the use of mechanical circulatory support devices in the Canadian context. Representatives from all Canadian centers with active mechanical circulatory support programs were invited to participate and participants included surgeons and cardiologists, as well as other affiliated health professionals. Opinions were solicited from the workshop participants and a series of recommendations were formulated.

Assisted Circulation↗