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Vivek Rao

Publications and source records attributed to Vivek Rao.

At least 19 recordsLinked to original sources
PubMed2026

Inflammasome activation dictates the efficacy of antimycobacterial activity of frontline TB drugs.

Recent developments in tuberculosis (TB) treatment have identified an enormous potential of host-directed therapies (HDT)) in achieving better and faster control of infection. We have previously demonstrated the synergistic effect of sertraline (SRT) with frontline TB drugs in clearing infection in murine tissues. Our attempts to uncover the mechanistic basis of this enhancement, using sertraline as a probe, help identify host signalling pathways critical for controlling Mycobacterium tuberculosis (Mtb). We identify a significant role for sertraline-mediated modulation of mitochondrial physiology and consequent reactive oxygen species (ROS) generation as a secondary signal, leading to greater IL-1β release and K+ efflux from macrophages via NLRP3 inflammasome activation. We thus highlight an important relationship between mitochondrial physiology and inflammasome activation, enabling infected macrophages to better control Mtb.

Animals↗
PubMed2006

Role of endothelin-1 and nitric oxide bioavailability in transplant-related vascular injury: comparative effects of rapamycin and cyclosporine.

BACKGROUND: Cyclosporine (CyA) is associated with many side effects, including endothelial dysfunction and transplant vasculopathy (TxV). We previously demonstrated that CyA results in impairment of nitric oxide bioavailability and enhanced sensitivity to endothelin-1 (ET-1). In this study, we evaluated rapamycin (SRL) for its effects on the endothelium. METHODS AND RESULTS: Lewis rats (n = 8) were injected with SRL (1.5 mg/kg), CyA (5 mg/Kg), or saline (Con) intraperitoneally daily for 2-weeks. Thoracic aortic segments were assessed for endothelial-dependent (Edep) and independent (Eind) relaxation after exposure to acetylcholine and sodium nitroprusside by deriving the percent maximum relaxation (Emax). ET-1 plasma levels were also measured. Thoracic aortic expression of endothelial nitric oxide synthase (eNOS), ET(A) and ET(B) receptors (Rc), were determined. Oxidative injury was assessed by changes in 8-isoprostane levels. CyA exposure resulted in lower Edep vasorelaxation compared with control and SRL (Emax: SRL, 58+/-4%; CyA, 24+/-7%; Con, 52+/-8%; P=0.001). No differences in Eind vasorelaxation were seen. CyA exposure also increased sensitivity to ET-1 (% maximum contraction [Cmax]: Con, 211+/-8%; SRL, 230+/-5%; CyA, 259+/-3%; P=0.04). Only SRL treatment reduced ET-1 plasma levels. CyA reduced eNOS expression by 30% and increased ETA Rc expression by 34% compared with both Con and SRL (P=0.02). CyA resulted in higher 8-isoprostane levels (CyA, 50+/-2%; SRL, 3+/-3%; Con, 2+/-5%; P=0.02). CONCLUSIONS: CyA results in vascular dysfunction characterized by impairment of Edep vasorelaxation and enhanced sensitivity to vasospasm. SRL did not impair Edep vasorelaxation or increase sensitivity to vasospasm while lowering ET-1 levels and preserving eNOS protein expression. We conclude that SRL is less deleterious to the vasculature than CyA and may prevent TxV by these mechanisms.

Acetylcholine↗
PubMed2006

Elevated endothelin-1 levels impair nitric oxide homeostasis through a PKC-dependent pathway.

BACKGROUND: Endothelin-1 (ET-1) plays an important role in the maintenance of vascular tone and pathological states such as ischemia/reperfusion (I/R) injury, coronary vasospasm, and cardiac allograft vasculopathy. We assessed the effects of elevated ET-1 levels as seen after I/R to determine if ET-1 modulates nitric oxide (NO) production via the translocation of specific protein kinase C (PKC) isoforms. METHODS AND RESULTS: Human saphenous vein endothelial cells (HSVECs) (n=8) were incubated with ET-1 or phosphate-buffered saline (PBS) for 24 hours. NO production was determined in the supernatant by measuring nitrate/nitrite levels. Protein expression of endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), caveolin-1 and PKC were determined. Lastly, PKC translocation and activity were assessed after exposure to the drug of interest. HSVECs exposed to ET-1 displayed decreased NO production. PKC inhibition reduced NO production, whereas PKC activation increased production. NO production was maintained when HSVECs exposed to ET-1 were treated with the PKC agonist, PMA. eNOS protein expression was reduced after ET-1 treatment. PKC inhibition also downregulated eNOS protein expression, whereas PMA upregulated expression. ET-1 exposure led to a significant increase in PKCdelta and PKCalpha translocation compared with control, whereas translocation of PKClambda was inhibited. ET-1 exposure significantly reduced overall PKC activity compared with control. CONCLUSIONS: Our study demonstrates that high levels of ET-1 impair endothelial NO production via an isoform-specific PKC-mediated inhibition of eNOS expression. ET-1 antagonism with bosentan stimulates translocation of PKClambda and leads to increased PKC activity and NO production. ET-1 antagonism may provide a novel therapeutic strategy to improve vascular homeostasis.

Alkaloids↗
PubMed2006

The Toronto Risk Score for adverse events following cardiac surgery.

OBJECTIVE: To develop and validate an objective and reliable measure of acuity that will identify high-risk patients and predict length of stay following all cardiac surgery procedures. METHODS: Logistical regression analysis of 12,683 patients undergoing cardiac surgery between 1996 and 2000 was used to identify the independent predictors of postoperative adverse events (AEs, defined as death, myocardial infarction, low cardiac output syndrome, postoperative renal failure, stroke or deep sternal wound infection). The rounded ORs for each of the 18 predictors of AEs were summed to calculate the Toronto Risk Score (TRS) for each patient. Weighted linear regression was used to determine the relationship between TRS and length of stay in the 4378 patients who underwent cardiac surgery between 2001 and 2002. RESULTS: TRS was significantly associated with cardiovascular intensive care unit length of stay (R2=0.85, slope=0.42, intercept=0.4; P<0.001). For each unit increase in TRS, cardiovascular intensive care unit length of stay increased by 0.4+/-0.05 days. TRS was also significantly associated with total postoperative length of stay (R2=0.88, slope=0.71, intercept=4.9; P<0.001). TRS captured a significant increase in acuity from 1996 and 2000 (5.12+/-3.5) to 2001 and 2002 (5.54+/-3.5; P<0.001). Despite increased acuity, AEs were reduced in 2001 and 2002 (8.1%) compared with 1996 to 2000 (9.8%; P=0.012). CONCLUSIONS: The TRS is a valid measure of acuity that can identify patients who are at high risk of experiencing an AE and having prolonged length of stay after any cardiac surgery procedure, capture changes in acuity over time and allow for continuous quality performance evaluation.

Aged↗
PubMed2006

Non-utilization of hearts and lungs after consent for donation: a Canadian multicentre study.

PURPOSE: To identify reasons why hearts and lungs from consented adult organ donors are not transplanted and identify changes in practice aimed at increasing their utilization rates. A greater potential may exist in Canada to improve utilization rates for hearts and lungs given their comparatively suboptimal rates (kidneys 85%, livers 84%, hearts 35% and lungs 23% reported in 2001). METHODS: Four Canadian organ procurement organizations participated. All adult organ donation cases for the calendar year 2002 were reviewed and included if consent for organ donation was obtained. An organ donation framework was established to highlight key areas where organs are lost from the transplantation stream. Organ donor cases were analyzed through this framework. RESULTS: A utilization rate of 39% (42/107) for heart and 28% (29/105) for lung donors was found, comparable to Canadian and international rates. Organ function was the most frequently cited reason for non-utilization, followed by donor characteristics and logistical issues. Suggestions for alternate management, potentially resulting in organ utilization, were made in 20 of 65 (31%) hearts and 28 of 156 (18%) lungs. Variable practices, around consent for individual organs and offering of organs consented, remained significant barriers to successful transplantation. CONCLUSION: Target areas for changes in practice included consenting and offering of all organs. Management of "marginal" organs should include resuscitation and reevaluation thus allowing potential organ rescue and utilization. Although there is considerable pressure to increase organs for transplantation, any such mechanism will not be judged successful unless recipient graft survival rates remain acceptable.

Adult↗
PubMed2006

Short- and long-term results of triple valve surgery in the modern era.

BACKGROUND: Triple valve surgery is usually complex and carries a reported operative mortality of 25% and 10-year survival of 40%. We examined surgical results in the modern era. METHODS: A total of 174 consecutive patients, mean age 58 +/-12 years underwent triple valve surgery from 1990 to 2004. The most common aortic and mitral valve disease was rheumatic disease (61%), followed by prosthetic valve dysfunction (22%). Tricuspid valve disease was functional regurgitation in 72% of patients. Ninety-four percent of patients were in New York Heart Association class III and IV, and 60% had had previous cardiac operations. The aortic valve procedures consisted of 160 replacements and 14 repairs, the mitral valve procedures, 153 replacements and 21 repairs, and the tricuspid valve procedures, 12 replacements and 162 repairs. Univariate and multivariable analyses were performed to identify predictors of early and late survival. RESULTS: Operative mortality was 13% (n = 22). Univariate factors associated with mortality included urgent surgery, shock, tricuspid valve replacement, preoperative renal failure, and peripheral vascular disease. Survival at 5 and 10 years was 75% and 61%, respectively. Seventy-three percent of patients were in New York Heart Association class I and II at their most recent follow-up. Ten-year freedom from thromboembolism was 88%, from anticoagulation-related hemorrhage, 83%, from endocarditis, 96%, and from cardiac reoperation, 92%. CONCLUSIONS: Patients with advanced rheumatic valve disease and prosthetic valve dysfunction are at risk for requiring triple valve surgery. Compared with historic reports, the results of triple valve surgery, primary and reoperative, have improved. Although early mortality is high, long-term and event-free survival are comparable with that of patients undergoing single valve replacement.

Adult↗
PubMed2006

Aortic valve replacement: a safe and durable option in patients with impaired left ventricular systolic function.

BACKGROUND: The natural history of aortic valve disease associated with ventricular dysfunction is dismal. Aortic valve replacement (AVR) is associated with increased mortality in patients with left ventricular dysfunction and the long-term outcome in these patients is not well-known. We evaluated perioperative outcomes and long-term results in patients with impaired left ventricular systolic function undergoing AVR. METHODS: Retrospective analysis identified 132 consecutive patients with a left ventricular ejection fraction (LVEF)<40% who underwent AVR with or without concomitant coronary artery bypass grafting (CABG) between 1990 and 2003. Patients with other valve pathology were excluded. RESULTS: Ages ranged from 29 to 94 years (mean 63+/-12), and 117 patients (89%) were male. Preoperatively, 82% were in NYHA III-IV. Sixty patients (45%) underwent AVR for severe aortic stenosis (AS) whilst 72 (55%) had aortic insufficiency (AI). In the AS group, the mean LVEF and aortic valve area were 26+/-4% and 0.8+/-0.4 cm(2), respectively. AI patients had a mean LVEF of 27+/-6% and a mean left ventricular end systolic diameter of 52+/-9 mm. Fifty-seven (43%) required concomitant CABG. There were only three perioperative deaths (2.3%) and no strokes. One patient (0.8%) had postoperative renal failure, and one suffered a myocardial infarct. Nine patients (6.9%) required a postoperative IABP. LVEF increased to 29+/-10% and 34+/-12% after six months in the AS and AI groups, respectively. The mean follow-up period was 6.1 years and no differences between the AS and AI groups were observed with respect to either perioperative or long-term outcomes. Overall survival was 96%, 79% and 55% at 1, 5 and 10 years, respectively. CONCLUSIONS: The long asymptomatic course of AS and AI means that many patients have impaired ventricular function at diagnosis. This study demonstrates that AVR in such patients can be performed with low perioperative morbidity and mortality. The outlook after surgery is excellent. A 10-year-survival of 55% compares favourably with heart transplantation and particularly with medical therapy. AVR is a safe, effective and durable option, which should not be denied to patients on the basis of low LVEF alone.

Adult↗
PubMed2006

Permanent pacing after cardiac transplantation in the era of extended donors.

BACKGROUND: Early results with bicaval anastomosis have shown a decreased requirement for permanent pacing (PPM) after transplantation (Tx). It is unclear whether this remains true in the current era of extended donor criteria. The objective of the present study was to characterize the need for post-Tx PPM requirements in the current bicaval era and to determine factors associated with need for pacing. METHODS: The local cardiac Tx database, hospital records and electrophysiology laboratory database were cross-referenced for information on patients in the pre-, peri- and post-Tx period. RESULTS: Between 2000 and 2004, 88 patients received a cardiac Tx using bicaval anastomosis. At post-Tx, 18 of 88 (20.5%) patients required a PPM. The incidence of single- and dual-chamber PPM was 31.3% and 68.7%, respectively. Mean donor age for patients requiring post-Tx PPM was 44.7 +/- 15.3 years compared with 35.7 +/- 14.4 years for those with no PPM requirement (p = 0.019). For every 5-year increase in donor age the risk for post-Tx PPM increased 1.234-fold (95% confidence interval [CI] 1.022 to 1.489, p = 0.0289). Recipient age, gender, amiodarone use, year of transplant, surgeon and surgical times were not associated with PPM requirements after cardiac Tx. CONCLUSIONS: Pacing requirements after heart transplantation, in the era of extended donor criteria, exceed the previously published rates of 0% to 5%. The advantage of bicaval anastomosis in decreasing pacing needs post-Tx does not exist in the era of extended donor criteria, specifically in the older donor age group.

Adult↗
PubMed2006

Basiliximab versus rabbit anti-thymocyte globulin for induction therapy in patients after heart transplantation.

BACKGROUND: The use of basiliximab or rabbit anti-thymocyte globulin (RATG) for induction therapy has significantly reduced the incidence of acute rejection episodes post-transplantation. The purpose of this study was to compare the safety and efficacy of basiliximab vs RATG in a population of adult heart transplant recipients. METHODS: We retrospective analyzed the safety and efficacy of basiliximab compared with RATG among 48 adult heart transplant recipients at our center. Twenty-five patients received basiliximab (20 mg on days 0 and 4 after heart transplantation), and 23 patients received RATG (1.5 mg/kg for 3 days). A standard triple-drug immunosuppression regimen was administered to all patients. RESULTS: The average biopsy score (ABS) at 1 month was 0.79 +/- 0.18 in the Basiliximab Group vs 0.47 +/- 0.2 in the RATG group (p = 0.023) and at 3 months was 0.75 +/- 0.24 in the Basiliximab Group vs 0.46 +/- 0.12 in the RATG Group (p = 0.032). At 6 months after transplantation, the difference between groups was not statistically significant (0.97 +/- 0.23 vs 0.58 +/- 0.17, p = .14). At 12 months the ABS was 0.85 +/- 0.4 in the Basiliximab Group vs 0.63 +/- 0.15 in the RATG Group (p = 0.12), and the number of episodes of infection was similar in both groups (19 vs 26; p = 0.16). There was no correlation between cumulative cyclosporine doses and rejection. Creatinine clearance levels were not statistically different between groups at baseline and up to 12 months after heart transplantation. Three patients died in the Basiliximab Group, and 2 patients died in the RATG Group. CONCLUSIONS: Rabbit anti-thymocyte globulin is more effective than basiliximab for prevention of rejection episodes after heart transplantation. Both induction agents provide similar safety profile.

Adult↗
PubMed2006

Reoperation is not an independent predictor of mortality during aortic valve surgery.

OBJECTIVE: Reoperations on aortic valves are associated with increased mortality, which may affect valve prosthesis selection at the time of initial aortic valve replacement. We analyzed our experience to determine whether reoperation itself independently predicts mortality during aortic valve surgery. METHODS: Demographic, intraoperative, and outcome data were collected prospectively on patients undergoing primary or redo aortic valve replacement or Bentall procedures after previous aortic valve replacement with or without concomitant coronary bypass grafting at a single institution from 1990 through 2002. Logistic regression analyses validated by means of bootstrap methodology identified the predictors of hospital mortality and the independent effect of reoperation. RESULTS: Of 2673 patients undergoing aortic valve surgery, 2375 were primary operations, 216 were reoperations, and 82 were Bentall-after-aortic valve replacement procedures. Of 298 reoperations, 32 were third and 5 were fourth procedures. Mortality was 2.3% for primary operations, 4.6% for redo aortic valve replacement, and 2.4% for Bentall-after-aortic valve replacement procedures. Most patients underwent elective procedures, with mortalities of 1.6%, 1.7%, and 2.5%, respectively. Hospital mortality was independently predicted by peripheral vascular disease (odds ratio, 3.6), active endocarditis (odds ratio, 2.9), worsening New York Heart Association class (odds ratio, 2.3), and need for annular enlargement (odds ratio, 2.1). Reoperation itself did not predict hospital mortality. CONCLUSIONS: The risk of mortality during aortic valve surgery is due mostly to active endocarditis, New York Heart Association class, and comorbidity. We failed to find a significant effect of reoperation on perioperative mortality. Mechanical valves, with their attendant anticoagulation-related morbidity, should not be implanted solely because of anticipated high mortality associated with bioprosthetic rereplacement.

Aged↗
PubMed2006

Canadian Cardiovascular Society consensus conference recommendations on heart failure 2006: diagnosis and management.

Heart failure remains a common diagnosis, especially in older individuals. It continues to be associated with significant morbidity and mortality, but major advances in both diagnosis and management have occurred and will continue to improve symptoms and other outcomes in patients. The Canadian Cardiovascular Society published its first consensus conference recommendations on the diagnosis and management of heart failure in 1994, followed by two brief updates, and reconvened this consensus conference to provide a comprehensive review of current knowledge and management strategies. New clinical trial evidence and meta-analyses were critically reviewed by a multidisciplinary primary panel who developed both recommendations and practical tips, which were reviewed by a secondary panel. The resulting document is intended to provide practical advice for specialists, family physicians, nurses, pharmacists and others who are involved in the care of heart failure patients. Management of heart failure begins with an accurate diagnosis, and requires rational combination drug therapy, individualization of care for each patient (based on their symptoms, clinical presentation and disease severity), appropriate mechanical interventions including revascularization and devices, collaborative efforts among health care professionals, and education and cooperation of the patient and their immediate caregivers. The goal is to translate best evidence-based therapies into clinical practice with a measureable impact on the health of heart failure patients in Canada.

Canada↗
PubMed2006

Improving the identification of patients at risk of postoperative renal failure after cardiac surgery.

BACKGROUND: Preoperative renal insufficiency is an important predictor of the need for postoperative renal replacement therapy (RRT). Serum creatinine (sCr) has a limited ability to identify patients with preoperative renal insufficiency because it varies with age, sex, and muscle mass. Calculated creatinine clearance (CrCl) is an alternative measure of renal function that may allow better estimation of renal reserve. METHODS: Data were prospectively collected for consecutive patients who underwent cardiac surgery requiring cardiopulmonary bypass at a tertiary care center. The relation between CrCl (Cockcroft-Gault equation) and RRT was initially described using descriptive statistics, logistic regression, and receiver operating curve analysis. Based on these analyses, preoperative renal insufficiency was defined as CrCl of 60 ml/min or less. Preoperative renal function was classified as moderate insufficiency (sCr > 133 microM), mild insufficiency (100 microM < sCr < or = 133 microM), occult insufficiency (sCr < or = 100 microM and CrCl < or = 60 ml/min), or normal function (sCr < or = 100 microM and CrCl > 60 ml/min). The independent association of preoperative renal function with RRT was subsequently determined using multiple logistic regression. RESULTS: Of the 10,751 patients in the sample, 137 (1.2%) required postoperative RRT. Approximately 13% of patients with normal sCr had occult renal insufficiency. Occult renal insufficiency was independently associated with RRT (odds ratio, 2.80; 95% confidence interval, 1.39-5.33). The magnitude of this risk was similar to patients with mild renal insufficiency (P = 0.73). CONCLUSIONS: The inclusion of a simple CrCl-based criterion in preoperative assessments may improve identification of patients at risk of needing postoperative RRT.

Acute Kidney Injury↗
PubMed2006

Trans-cyclopropanation of mycolic acids on trehalose dimycolate suppresses Mycobacterium tuberculosis -induced inflammation and virulence.

Recent studies have shown that fine structural modifications of Mycobacterium tuberculosis cell envelope lipids mediate host cell immune activation during infection. One such alteration in lipid structure is cis-cyclopropane modification of the mycolic acids on trehalose dimycolate (TDM) mediated by proximal cyclopropane synthase of alpha mycolates (pcaA), a proinflammatory lipid modification during early infection. Here we examine the pathogenetic role and immunomodulatory function of mycolic acid cyclopropane stereochemistry by characterizing an M. tuberculosis cyclopropane-mycolic acid synthase 2 (cmaA2) null mutant (Delta cmaA2) that lacks trans-cyclopropanation of mycolic acids. Although titers of WT and Delta cmaA2 organisms were identical during mouse infection, Delta cmaA2 bacteria were hypervirulent while inducing larger granulomas than WT M. tuberculosis. The hypervirulence of the Delta cmaA2 strain depended on host TNF-alpha and IFN-gamma. Loss of trans-cyclopropanation enhanced M. tuberculosis-induced macrophage inflammatory responses, a phenotype that was transferable with petroleum ether extractable lipids. Finally, purified TDM lacking trans-cyclopropane rings was 5-fold more potent in stimulating macrophages. These results establish cmaA2-dependent trans-cyclopropanation of TDM as a suppressor of M. tuberculosis-induced inflammation and virulence. In addition, cyclopropane stereochemistries on mycolic acids interact directly with host cells to both positively and negatively influence host innate immune activation.

Animals↗
PubMed2006

Does a pre-left ventricular assist device screening score predict long-term transplantation success? A 2-center analysis.

BACKGROUND: A risk factor summation score was previously validated to successfully predict survival after insertion of a left ventricular assist device (LVAD). We investigated whether this scoring system also predicts clinical outcomes after eventual heart transplantation in LVAD recipients. METHODS: A retrospective review was performed on 153 consecutive patients who received an LVAD as a bridge to transplantation at 2 large-volume centers from 1996 to 2003. The scoring system was used to designate low- and high-scoring groups. RESULTS: Thirty-day mortality and 5-year survival after transplantation were equivalent between groups (4.46% versus 7.32% and 76% versus 70%, respectively). No difference was seen in length of posttransplantation ventilator dependence (2.83 +/- 0.49 versus 3.3 +/- 0.72 days) or intensive care unit monitoring (6.38 +/- 0.77 versus 6.97 +/- 1.1 days). However, low-scoring patients had a significantly decreased duration of inotrope support (5.57 +/- 0.45 versus 7.74 +/- 1.0 days, P = .035). CONCLUSION: A risk factor summation score may predict which LVAD patients will require prolonged inotropic support following heart transplantation. However, survival in high-risk (elevated score) LVAD patients following heart transplantation is comparable to low-risk groups, favoring the continued practice of LVAD implantation as a bridge to transplantation even in high-risk patients.

Female↗
PubMed2005

Off-pump coronary artery surgery for reducing mortality and morbidity: meta-analysis of randomized and observational studies.

OBJECTIVES: The purpose of this study was to assess the effects of off-pump coronary bypass surgery (OPCAB) on mortality and morbidity. BACKGROUND: Despite its potential for reducing morbidity and mortality, OPCAB's role in clinical practice remains controversial. METHODS: A meta-analysis of 37 randomized controlled trials (RCTs) (n = 3,449) and 22 risk-adjusted (logistic regression or propensity-score) observational studies (n = 293,617) was performed. Two reviewers performed literature searches (MEDLINE, EMBASE, PubMed, reference lists), quality assessment, and data extraction. Treatment effects were calculated as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: In RCTs, OPCAB was associated with reduced atrial fibrillation (OR 0.59; 95% CI 0.46 to 0.77) and trends toward reduced 30-day mortality (OR 0.91 95% CI 0.45 to 1.83), stroke (OR 0.52; 95% CI 0.25 to 1.05), and myocardial infarction (OR 0.79; 95% CI 0.50 to 1.25). Observational studies showed OPCAB to be associated with reduced 30-day mortality (OR 0.72; 95% CI 0.66 to 0.78), stroke (OR 0.62; 95% CI 0.55 to 0.69), infarction (OR 0.66; 95% CI 0.50 to 0.88), and atrial fibrillation (OR 0.78; 95% CI 0.74 to 0.82). At one to two years, OPCAB was associated with trends toward reduced mortality, but also increased repeat revascularization (RCT: OR 1.75, 95% CI 0.78 to 3.94; Observational: OR 1.35, 95% CI 0.76 to 2.39). CONCLUSIONS: Randomized controlled trials did not find, aside from atrial fibrillation, the statistically significant reductions in short-term mortality and morbidity demonstrated by observational studies. These discrepancies might be due to differing patient-selection and study methodology. Future studies must focus on improving research methodology, recruiting high-risk patients, and collecting long-term data.

Acute Kidney Injury↗
PubMed2005

Predictors of low cardiac output syndrome after isolated aortic valve surgery.

BACKGROUND: Low cardiac output syndrome (LCOS), defined as the need for postoperative intraaortic balloon pump or inotropic support for >30 minutes in the intensive care unit, remains a relatively common complication of aortic valve (AV) surgery. The aim of this study is to identify the preoperative predictors of LCOS in patients undergoing isolated AV surgery. METHODS AND RESULTS: We conducted a retrospective review of data prospectively entered into an institutional database. Between 1990 and 2003, 2255 patients underwent isolated AV surgery with no other concomitant cardiac surgery. The independent predictors of LCOS and operative mortality (OM) were determined by stepwise logistic regression analysis. The overall prevalence of LCOS was 3.9%. The independent predictors of LCOS were (odds ratio in parentheses) renal failure (5.0), earlier year of operation (4.4), left ventricular ejection fraction <40% (3.6), shock (3.2), female gender (2.8), and increasing age (1.02). Overall OM was 2.9%. The OM was higher in patients who experienced LCOS (38% versus 1.5%; P<0.001). The independent predictors of mortality were (odds ratio in parentheses) preoperative renal failure (8.3), urgency of surgery (3.4), previous stroke (2.9), congestive heart failure (2.6), previous cardiac surgery (2.3), hypertension (1.7), and small AV size (1.3). CONCLUSIONS: Low-output syndrome is associated with significantly increased morbidity and mortality. Novel strategies to preserve renal function, optimization of preexisting heart failure symptoms, and avoidance of prosthesis-patient mismatch may reduce the incidence of LCOS and lead to improved results after AV surgery.

Aged↗