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Biomedical subjects

Keyvan Karkouti

Publications and source records attributed to Keyvan Karkouti.

At least 19 recordsLinked to original sources

Derivation of a risk index for the prediction of massive blood transfusion in liver transplantation.

Massive blood transfusion (MBT) remains a serious and common occurrence in liver transplantation surgery. This retrospective cohort study was undertaken to identify preoperative predictors of MBT and to develop a risk index for MBT in liver transplantation. Data were retrospectively collected on all liver transplantations carried out at a single institution between January 1998 and March 2004. Multivariable logistic regression analysis was used to identify independent predictor variables of MBT, defined as >/=6 units of red blood cell concentrate (RBC) in the first 24 hours of surgery. The model was internally validated by bootstrapping. Of the 460 liver transplant recipients, 193 (42%) received >/=6 units of RBC within 24 hours of surgery. Unadjusted analyses identified 12 preoperative predictors of MBT: age, height, gender, repeat transplantation, etiology of liver failure, and preoperative laboratory values (hemoglobin concentration, platelet count, international normalized ratio for prothrombin activity [INR], albumin, total bilirubin, and creatinine). In multivariable logistic regression, 7 independent predictors of MBT were identified: age (>40 years), hemoglobin concentration (</=10.0 g/dL), INR (1.2-1.99, and >2.0), platelet count (</=70 x 10(9)/L), creatinine (>/=110 micromol/L for female subjects and >/=120 micromol/L for male subjects), albumin (< 28 g/L), and repeat transplantation. The area under the receiver-operating characteristic curve (ROC) for the model was 0.82. By using the regression beta coefficients to derive weights for each of these predictors, a risk index was developed that assigned each patient a score between 0 and 8. The ROC for this risk index was 0.79. MBT in liver transplantation surgery can be accurately predicted by 7 readily available preoperative predictors.

Adult↗

Intravenous iron and recombinant erythropoietin for the treatment of postoperative anemia.

PURPOSE: To determine if early recovery from severe post-operative anemia is accelerated by iv iron therapy alone or in combination with recombinant erythropoietin (EPO). METHODS: In this double-blinded, placebo-controlled randomized study, consenting adult patients without preoperative anemia whose hemoglobin concentration (Hb) was 70 to 90 g x L(-1) on the first day after cardiac or orthopedic surgery (POD 1) were assigned to one of three groups: control, iv iron alone (200 mg of iron sucrose on POD 1, 2, and 3) or in combination with EPO (600 U x kg(-1) on POD 1 and 3). The primary outcome was increase in Hb (adjusted for red blood cell transfusions) from POD 1 to 7. Analysis was by intention-to-treat in patients for whom the primary outcome was available. Group effect was analyzed by the ANOVA test, and between-group differences were specified with a Duncan multiple-range test. RESULTS: The primary outcome was available in 31 of 38 randomized patients. The average POD 1 Hb was 84 +/- 4 g x L(-1). There were no between-group differences in outcomes except for higher reticulocyte counts on POD-7 in the combination group. The average adjusted one-week increases in Hb were 7 +/- 8 g x L(-1) in the control group (n = 10), 9 +/- 9 g x L(-1) in the iv iron group (n = 11), and 10 +/- 14 g x L(-1) in the combination group (n = 10). The average adjusted six-week increases in Hb were 37 +/- 14 g x L(-1) in the control group, 40 +/- 7 g x L(-1) in the iv iron group, and 45 +/- 12 g x L(-1) in the combination group. CONCLUSION: Early postoperative treatment with iv iron alone or in combination with EPO does not appear to accelerate early recovery from postoperative anemia.

Analysis of Variance↗

Platelet transfusions are not associated with increased morbidity or mortality in cardiac surgery.

PURPOSE: To determine the independent relationship between leukoreduced platelet transfusions and adverse events in cardiac surgery. METHODS: In this observational study, detailed baseline and perioperative data were prospectively collected on consecutive patients who underwent cardiac surgery at a single institution from 1999 to 2004. The independent associations of platelet transfusion with clinical outcomes (low output syndrome, myocardial infarction, stroke, renal failure, sepsis, and death) were determined by multivariable logistic regression analysis and propensity score case-control analysis. RESULTS: Of the 11,459 patients analyzed, 2,174 (19%) received (leukoreduced) platelets - 1,408 received 5 U, 471 received 10 U, 140 received 15 U, and 155 received 20 or more units. Although all measured adverse event rates were higher in those who received platelets, in neither the logistic regression analyses nor the propensity score analyses was there any association between platelet transfusion and any of the adverse events. CONCLUSIONS: Transfusion of leukoreduced platelets in cardiac surgery is not associated with adverse clinical outcomes when adjustments are made for important confounders.

Cardiac Surgical Procedures↗

Prognostic value of postoperative proteinuria in cardiac surgery: a pilot study.

BACKGROUND: Proteinuria is a non-specific marker of inflammation that may reflect the glomerular component of systemic capillary leak. The objective of this pilot study was to determine if postoperative proteinuria is associated with adverse outcomes following cardiac surgery with cardiopulmonary bypass. METHODS: Eligible patients were individuals undergoing cardiac surgery with cardiopulmonary bypass who did not have severe pre-existing renal dysfunction. Urine was collected after induction of anesthesia (baseline) and two to four hours after arrival to the intensive care unit (ICU). Proteinuria was measured as random protein creatinine ratio in g.mol(-1). Adverse events were defined a priori as prolonged ICU stay (> or = 90th percentile) and organ dysfunction. The relationship between proteinuria and adverse events was assessed by bivariate (Chi-square or Fisher's exact tests) and multivariable (multiple logistic regression) analyses. RESULTS: The study included 197 (of 243 eligible) patients. Postoperative proteinuria (protein creatinine ratio > or = 30 g.mol(-1)) was associated with prolonged (> or = four days) ICU stay [odds ratio (OR) 7.0; 95% confidence interval (CI) 2.8-17.1] and organ dysfunction (OR 3.9; CI 1.9-8.1). After adjustment for confounders, proteinuria was associated with a 3.2-fold increase in the odds of both prolonged ICU stay (CI 1.1-9.7) and organ dysfunction (CI 1.4-7.0). CONCLUSIONS: Proteinuria two to four hours after cardiac surgery with cardiopulmonary bypass may be a useful marker for systemic capillary leak and adverse postoperative events. Large prospective studies are needed to confirm these findings.

Anesthesia, General↗

Prediction of massive blood transfusion in cardiac surgery.

PURPOSE: In cardiac surgery with cardiopulmonary bypass (CPB), excessive blood loss requiring the transfusion of multiple red blood cell (RBC) units is a common complication that is associated with significant morbidity and mortality. The objective of this study was to develop a prediction rule for massive blood transfusion (MBT) that could be used to optimize the management of, and research on, at-risk patients. METHODS: Data were collected prospectively over the period from 2000 to 2005, on patients who underwent surgery with CPB at one hospital. Patients who received > or = five units of RBC within one day of surgery were classified as MBT. Logistic regression was used to appropriately select and weigh perioperative variables in the prediction rule, which was developed on the initial 60% of the sample and validated on the remaining 40%. RESULTS: Of the 10,667 patients included, 925 (8.7%) had MBT. The clinical prediction rule included 12 variables (listed in order of predictive value: CPB duration, preoperative hemoglobin concentration, body surface area, nadir CPB hematocrit, previous sternotomy, preoperative shock, preoperative platelet count, urgency of surgery, age, surgeon, deep hypothermic circulatory arrest, and type of procedure) and was highly discriminative (c-index = 0.88). In the validation set, those classified as low-, moderate-, and high-risk by a simple risk score derived from the prediction rule had a 5%, 27%, and 58% chance of MBT, respectively. CONCLUSION: A clinical prediction rule was developed that accurately identified patients at low-risk or high-risk for MBT. Studies are needed to determine the external generalizability and clinical utility of the prediction rule.

Age Factors↗

Determinants of complications with recombinant factor VIIa for refractory blood loss in cardiac surgery.

PURPOSE: Recombinant factor VIIa (rFVIIa) is being used for refractory, excessive blood loss (EBL) after cardiac surgery, but its safety for this indication is not known. METHODS: The unadjusted and risk-adjusted adverse event (AE) rates were compared between 114 consecutive cardiac surgical patients who received rFVIIa for refractory EBL and 541 concurrent patients who developed EBL but did not receive rFVIIa. Similarly, timing of rFVIIa therapy was assessed by dichotomizing rFVIIa patients based on median number of red blood cell (RBC) units received before therapy. The measured AE was a composite of death, stroke, renal failure, myocardial infarction, and major vein thrombosis. For risk adjustment, logistic regression models for this outcome were constructed using known predictors of AEs. RESULTS: The median RBC units transfused before rFVIIa therapy was eight. The AE rates in the untreated, early (< or = 8 U), and late (> 8 U) treated patients were 24% (129/541), 30% (20/66), and 60% (29/48). The risk-adjustment model included total RBC units, pump time, weaning difficulty, gender, weight, and age. The unadjusted and adjusted AE odds ratios (OR) in the treated vs untreated groups were 2.41 [confidence interval (CI) 1.58-3.67; P < 0.0001] and 1.04 (CI 0.60-1.81; P = 0.9). In the rFVIIa group, the adjusted AE OR was lower in the early treated group (OR 0.41; CI 0.18-0.92; P = 0.03). CONCLUSION: In cardiac surgical patients with refractory hemorrhage, rFVIIa therapy is not associated with increased risk of AEs, and early treatment may be associated with better outcomes.

Acute Kidney Injury↗

Case report: management of life-threatening oropharyngeal bleeding with recombinant factor VIIa.

PURPOSE: To report the use of recombinant factor VIIa (rFVIIa) for management of profuse oropharyngeal bleeding in a cirrhotic patient that nearly resulted in a 'cannot intubate, cannot ventilate' scenario. CLINICAL FEATURES: A 42-yr-old woman with end-stage liver disease presented for orthotopic liver transplantation. She was dialysis dependent and had marked coagulopathy [international normalized ratio (INR) = 3.1], without evidence of active bleeding. Following uneventful induction of anesthesia, routine airway manipulation for tracheal intubation caused profuse upper airway bleeding making visualization of her airway by direct laryngoscopy impossible. Moreover, several further attempts at tracheal intubation along with the bleeding made manual ventilation progressively more difficult, nearly resulting in a 'cannot intubate, cannot ventilate' scenario. In an attempt to control the bleeding, rFVIIa 4.8 mg iv was administered. Within five minutes, her INR had decreased to 1.1, bleeding was markedly reduced, the vocal cords were successfully visualized using an anterior commissure laryngoscope, and intubation of the trachea was achieved with the use of a gum-elastic bougie. Postintubation examination of the airway showed several abrasions along the right oropharyngeal wall with minimal bleeding. The remainder of surgery and postoperative airway management were uneventful. CONCLUSIONS: This report demonstrates that in the relatively uncommon setting of upper airway hemorrhage in a patient with pre-existing coagulopathy, rFVIIa can be effective in gaining rapid control of bleeding to facilitate visualization of the vocal cords and securing of the airway.

Adult↗

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↗

A propensity score case-control comparison of aprotinin and tranexamic acid in high-transfusion-risk cardiac surgery.

BACKGROUND: Cardiac surgery with cardiopulmonary bypass may result in excessive fibrinolysis and platelet (PLT) dysfunction, resulting in impaired hemostasis and excessive blood loss. Prophylactic use of the antifibrinolytic drugs aprotinin and tranexamic acid is thought to prevent these hemostatic defects. Their relative clinical utility and safety in high-transfusion-risk cardiac surgery, however, is not known. STUDY DESIGN AND METHODS: Using propensity scores, 449 patients who received aprotinin for high-transfusion-risk cardiac surgery were matched to 449 patients who received tranexamic acid from a pool of 10,870 consecutive patients who underwent cardiac surgery at a single center, 586 of whom received aprotinin and the remainder of whom received tranexamic acid. RESULTS: The two matched groups were well balanced in terms of measured perioperative variables. Blood product transfusion rates were similar in the aprotinin and tranexamic acid groups: red blood cells, 79 percent versus 76 percent (p = 0.3); PLTs, 56 percent versus 50 percent (p = 0.06); and plasma, 66 percent versus 61 percent (p = 0.1). Adverse events rates were comparable in the two groups, except for renal dysfunction (defined as a greater than 50% increase in creatinine concentration during the first postoperative week to >100 micromol/L in women and >110 micromol/L in men or a new requirement for dialysis support), which occurred in 24 percent (107/449) of aprotinin patients and 17 percent (75/449) of tranexamic acid patients (p = 0.01). CONCLUSIONS: Aprotinin and tranexamic acid have similar hemostatic effectiveness in high-transfusion-risk cardiac surgery. Within the confines of propensity score matching, our results suggest that aprotinin may be associated with renal dysfunction.

Adult↗

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↗

Erythropoietin is an effective clinical modality for reducing RBC transfusion in joint surgery.

PURPOSE: Efficacy trials of preoperative erythropoietin therapy (PET) recommend a dosing schedule that cannot always be adhered to in everyday clinical practice. Consequently, we instituted a flexible dosing schedule and routinely offered it to anemic patients [hemoglobin (Hb)] < or = 130 g x L(-1)) undergoing total joint arthroplasty (TJA). The purpose of this observational, cohort study was to assess the effectiveness of this practice in reducing red blood cell (RBC) transfusion. METHODS: After obtaining Institutional Ethics Board approval, data were collected prospectively on all patients who underwent TJA at our institution from July 1999 to June 2003. Patients with baseline Hb < or = 130 g x L(-1) were offered PET as follows: one to three sc injections (20,000 IU for those < or = 70 kg, and 40,000 IU for those > 70 kg) every three to seven days before surgery. Since treatment was not randomly assigned, multivariable logistic regression analysis and propensity score case-control matching were used to adjust for baseline differences in patient demographics and perioperative risk factors for RBC transfusion. The adjusted relationship between PET and RBC transfusion was then determined. RESULTS: Of the 1,782 patients that underwent TJA during the study period, 770 (47.9%) had a Hb < 130 g x L(-1). Of these patients, 214 received PET and their RBC transfusion rate was 16.4%, whereas the transfusion rate was 56.1% in those who did not receive PET (P < 0.0001). The adjusted odds ratio of RBC transfusion with PET was 0.33 (95% confidence interval = 0.21-0.49). CONCLUSION: PET, used as part of routine clinical practice, is an effective blood conservation modality.

Adult↗

Low hematocrit during cardiopulmonary bypass is associated with increased risk of perioperative stroke in cardiac surgery.

BACKGROUND: The relationship between degree of hemodilution during cardiopulmonary bypass (CPB) and perioperative stroke has not been fully elucidated. The objective of this observational study was to evaluate the relationship between nadir hematocrit during CPB and perioperative stroke while adjusting for variables known to have an association with stroke and anemia. METHODS: Perioperative data were prospectively collected on 10,949 consecutive patients who underwent cardiac surgery with CPB from 1999 to 2004 at a quaternary care hospital. Stroke was defined as a persistent neurologic deficit, consistent with a central nervous system lesion, occurring within 30 days of operation. Stroke was classified as perioperative if patients awoke from anesthesia with neurologic symptoms and postoperative if patients awoke without symptoms. Multivariable logistic regression analysis was used to control for confounding variables to obtain the independent relationship between nadir hematocrit during CPB and perioperative stroke. RESULTS: The prevalence of perioperative stroke was 1.0% (n = 110). An additional 50 patients had postoperative stroke. Nadir hematocrit during CPB was an independent predictor of perioperative stroke. After controlling for confounding variables, each percent decrease in hematocrit was associated with a 10% increase in the odds of suffering perioperative stroke (95% confidence interval, 4% to 18%; p = 0.002). The model was accurate (c-index = 0.85) and reliable (Hosmer-Lemeshow test p = 0.4). CONCLUSIONS: There is an independent, direct association between degree of hemodilution during CPB and risk of perioperative stroke. Prospective randomized clinical trials comparing different degrees of hemodilution during CPB are required to determine whether this is a cause-effect relationship or a simple association.

Aged↗

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↗

Recombinant factor VIIa for intractable blood loss after cardiac surgery: a propensity score-matched case-control analysis.

BACKGROUND: Cardiac surgery is occasionally complicated by massive blood loss that is refractory to standard hemostatic interventions. Recombinant factor VIIa (rF-VIIa) is being increasingly used as rescue therapy in such cases, but little information is available on its safety and efficacy for this indication. STUDY DESIGN AND METHODS: The outcomes of the first 51 cardiac surgery patients who received rF-VIIa for intractable blood loss (from November 2002 to February 2004) at a single institution according to a standardized clinical guideline were compared to 51 matched control patients, with the control patients identified from a large database and matched based on the propensity for massive blood loss. RESULTS: Blood loss and blood product usage were significantly decreased after 2.4 to 4.8 mg of rF-VIIa. In those treated after sternal closure (n = 32), there was a significant reduction in blood loss from the hour before to the hour after treatment: 100 (70, 285) mL (median [25th, 75th percentiles]; p < 0.0001). Except for a slower postoperative recovery and higher incidence of acute renal dysfunction, the adverse event rates were similar between the rF-VIIa-treated patients and their matched controls. CONCLUSIONS: These results suggest that rF-VIIa may be an effective rescue therapy for patients with intractable hemorrhage after cardiac surgery. A clinically important risk of stroke or other major thrombotic complications could not be ruled out by our study. Controlled clinical trials with adequate power to detect the impact of rF-VIIa therapy on morbidity and mortality therefore are necessary before one can recommend its routine use in patients undergoing cardiac surgery who have excessive bleeding.

Blood Coagulation↗

Mild to moderate atheromatous disease of the thoracic aorta and new ischemic brain lesions after conventional coronary artery bypass graft surgery.

BACKGROUND AND PURPOSE: The presence of new ischemic brain infarcts, detected by diffusion-weighted magnetic resonance imaging (DW-MRI), have been reported in considerable number of patients after cardiac surgery. We sought to determine the role of proximal thoracic aortic atheroma in predicting embolic events and new ischemic brain lesions in patients undergoing conventional coronary revascularization surgery. METHODS: Transesophageal echocardiography and epiaortic scanning was performed to assess the severity of aortic atherosclerosis in the ascending aorta and the aortic arch. Patients were allocated to either low-risk group, (intimal thickness < or =2mm), or high-risk group (intimal thickness >2mm). Transcranial Doppler was used to monitor the middle cerebral artery. DW-MRI was performed 3-7 days after surgery. The NEECHAM Confusion Scale was used for assessment and monitoring patient consciousness level. RESULTS: Patients in the high-risk group were considerably older; 71+/-6 (n=38) versus 67+/-6 (n=72) years, P=0.004 and were more likely to have impaired left ventricular function. Confusion was present in 6 (16%) patients in the high-risk group and 5 (7%) patients in the low-risk group. Patients in the high-risk group had a three-fold increase in median embolic count, 223.5 versus 70.0, P=0.0003. DW-MRI detected brain lesions were only present in patients from high-risk group, 61.5 versus 0%, P<0.0001. There was significant correlation between the NEECHAM scores and embolic count in the high-risk group; r=0.63, P<0.001. CONCLUSIONS: The findings of this investigation suggest that mild to moderate atheromatous disease of the ascending aorta and the aortic arch (intimal thickness >2mm) is a major contributor to ischemic brain injury after cardiac surgery.

Aged↗

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↗