John D. Klemperer

Intraoperative Red Blood Cell Transfusion During Coronary Artery Bypass Graft Surgery Increases the Risk of Postoperative Low-Output Heart Failure

Background— Hemodilutional anemia during cardiopulmonary bypass (CPB) is associated with increased mortality during coronary artery bypass graft (CABG) surgery. The impact of intraoperative red blood cell (RBC) transfusion to treat anemia during surgery is less understood. We examined the relationship between anemia during CPB, RBC transfusion, and risk of low-output heart failure (LOF). Methods and Results— Data were collected on 8004 isolated CABG patients in northern New England between 1996 and 2004. Patients were excluded if they experienced postoperative bleeding or received ≥3 units of transfused RBCs. LOF was defined as need for intraoperative or postoperative intra-aortic balloon pump, return to CPB, or ≥2 inotropes at 48 hours. Having a lower nadir HCT was also associated with an increased risk of developing LOF (adjusted odds ratio, 0.90; 95% CI, 0.82 to 0.92; P=0.016), and that risk was further increased when patients received RBC transfusion. When adjusted for nadir hematocrit, exposure to RBC transfusion was a significant, independent predictor of LOF (adjusted odds ratio, 1.27; 95% CI, 1.00 to 1.61; P=0.047). Conclusions— In this study, we observed that exposure to both hemodilutional anemia and RBC transfusion during surgery are associated with increased risk of LOF, defined as placement of an intraoperative or postoperative intra-aortic balloon pump, return to CPB after initial separation, or treatment with ≥2 inotropes at 48 hours postoperatively, after CABG. The risk of LOF is greater among patients exposed to intraoperative RBCs versus anemia alone.

Triiodothyronine therapy lowers the incidence of atrial fibrillation after cardiac operations

BACKGROUND Cardiopulmonary bypass results in a euthyroid sick state, and recent evidence suggests that perioperative triiodothyronine (T3) supplementation may have hemodynamic benefits. In light of the known effects of thyroid hormone on atrial electrophysiology, we investigated the effects of perioperative T3 supplementation on the incidence of postoperative arrhythmias. METHODS One hundred forty-two patients with depressed left ventricular function (ejection fraction < 0.40) undergoing coronary artery bypass grafting were randomized to either T3 or placebo treatment groups in a prospective, double-blind fashion. Triiodothyronine was administered as a 0.8 micrograms/kg intravenous bolus at the time of aortic cross-clamp removal followed by an infusion of 0.113 micrograms.kg-1.h-1 for 6 hours. Patients were monitored for the development of arrhythmias during the first 5 postoperative days. RESULTS The incidence of sinus tachycardia and ventricular arrhythmias were similar between groups. Triiodothyronine-treated patients had a lower incidence of atrial fibrillation (24% versus 46%; p = 0.009), and fewer required cardioversion (0 versus 6; p = 0.012) or anticoagulation (2 versus 10; p = 0.013) during hospitalization. Six patients in the T3 group versus 16 in the placebo group required antiarrhythmic therapy at discharge (p = 0.019). CONCLUSIONS Perioperative T3 administration decreased the incidence and need for treatment of postoperative atrial fibrillation.

Comprehensive Multimodality Blood Conservation: 100 Consecutive CABG Operations Without Transfusion

BACKGROUND Despite the recent introduction of a number of technical and pharmacologic blood conservation measures, bleeding and allogeneic transfusion remain persistent problems in open heart surgical procedures. We hypothesized that a comprehensive multimodality blood conservation program applied algorithmically on the basis of bleeding and transfusion risk would provide a maximum, cost-effective, and safe reduction in postoperative bleeding and allogeneic blood transfusion. METHODS One hundred consecutive patients undergoing coronary artery bypass grafting were prospectively enrolled in a risk factor-based multimodality blood conservation program (MMD group). To evaluate the relative efficacy and safety of this comprehensive approach, comparison was made with a similar group of 90 patients undergoing coronary artery bypass grafting to whom the multimodality blood conservation program was not applied but in whom an identical set of transfusion guidelines was enforced (control group). To evaluate the cost effectiveness of the multimodality program, comparison was also made between patients in the MMD group and a consecutive series of contemporaneous, diagnostic-related group-matched patients. RESULTS One hundred consecutive patients in the MMD group underwent coronary artery bypass grafting without allogeneic transfusion. This compared favorably with the control population in whom a mean of 2.2 +/- 6.7 units of allogeneic blood was transfused per patient (34 patients [38%] received transfusion). In addition, the volume of postoperative blood loss at 12 hours in the control group was almost double that of the MMD group (660 +/- 270 mL versus 370 +/- 180 mL [p < 0.001]). Total costs for the MMD group in each of the three major diagnostic-related groups were equivalent to or significantly less than those in the consecutive series of diagnostic-related group-matched patients. CONCLUSIONS Comprehensive risk factor-based application of multiple blood conservation measures in an optimized, integrated, and algorithmic manner can significantly decrease bleeding and need of allogeneic transfusion in coronary artery bypass grafting in a safe and cost-effective manner.

In-hospital outcomes of off-pump versus on-pump coronary artery bypass procedures: a multicenter experience ☆

BACKGROUND Concern about the possible adverse effects of the cardiopulmonary bypass (CPB) pump and advances in retractors and operative techniques to access all coronary segments have resulted in increased interest in off-pump coronary artery bypass (OPCAB) procedures. Four of the Northern New England Cardiovascular Disease Study Group centers initiated OPCAB programs in 1998. We compared the preoperative risk profiles and in-hospital outcomes of patients done off-pump with those done by conventional coronary artery bypass (CCAB) with CPB. METHODS Between 1998 and 2000, 1,741 OPCAB and 6,126 CCAB procedures were performed at these four medical centers. Minimally invasive direct coronary artery bypass grafting procedures were excluded. Data were available for patient and disease risk factors, extent of coronary disease and adverse in-hospital outcomes. RESULTS The OPCAB and CCAB groups were somewhat different in their preoperative patient and disease characteristics. The OPCAB patients were more likely to be female and to have peripheral vascular disease. The CCAB patients were more likely to have an ejection fraction less than 0.40 and be urgent or emergent at operation. However, overall predicted risk of in-hospital mortality, based on preoperative factors, was similar in the OPCAB and CCAB groups; the mean predicted risk was 2.6% (p = 0.567). Crude rates of mortality (2.54% OPCAB versus 2.57%, CCAB), intraoperative or postoperative stroke (1.33% versus 1.82%), mediastinitis (1.10% versus 1.37%), and return to the operating room for bleeding (3.46% versus 2.93%) did not differ significantly. The OPCAB patients did have a statistically significant reduction in the need for intraoperative or postoperative intraaortic balloon pump support (2.31% versus 3.41%; p = 0.023) and in the incidence of postoperative atrial fibrillation (21.21% versus 26.31%; p < 0.001). Adjustment for preoperative risk factors and extent of coronary disease did not substantially change the crude results. Median postoperative length of stay was significantly shorter (5 days versus 6 days, p < 0.001) for OPCAB patients than for CCAB patients. CONCLUSIONS This multicenter study showed that patients having OPCAB are not exposed to a greater risk of short-term adverse outcomes. These data also provided evidence that patients having OPCAB have significantly lower need for intraoperative or postoperative intraaortic balloon pump, lower rates of postoperative atrial fibrillation, and a shorter length of stay.

Cardiac Operations in Patients With Cirrhosis

BACKGROUND A retrospective review was performed to determine the outcome after cardiac operations in patients with a documented history of noncardiac cirrhosis. METHODS The charts of patients admitted to the cardiothoracic surgical service between 1990 and 1996 were reviewed, and 13 patients with a preoperative history of cirrhosis were identified. The severity of preoperative liver disease was graded according to the criteria of Child. RESULTS Most of the cases of cirrhosis were alcohol-related. Eight patients were classified as having Child class A and 5 as having Child class B cirrhosis. One hundred percent of patients with Child class B and 25% of those with Child class A cirrhosis had major complications. The postoperative chest tube output and transfusion requirements of these patients were approximately three times higher than average. The overall perioperative mortality rate was 31%. In patients with Child class B cirrhosis, the mortality rate was 80%. No patient with Child class A cirrhosis died. Deaths were related to gastrointestinal and septic complications, and not to cardiovascular failure. CONCLUSIONS These findings suggest that patients with minimal clinical evidence of cirrhosis can tolerate cardiopulmonary bypass and cardiac surgical procedures, whereas those with more advanced liver disease should not be offered operation.

Intraoperative autologous blood donation preserves red cell mass but does not decrease postoperative bleeding

BACKGROUND Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations. The benefit of the acute removal and reinfusion of fresh autologous blood around the time of cardiopulmonary bypass-a technique known as intraoperative autologous donation (IAD)-has not been universally accepted. We sought to more clearly evaluate the effects of IAD on allogeneic transfusion and postoperative bleeding by removing, preserving, and reinfusing a calculated maximum volume of fresh autologous whole blood. METHODS Ninety patients undergoing coronary artery bypass grafting or valvular operations were prospectively randomized to either have (IAD group) or not have (control group) calculated maximum volume IAD performed. Treatment was otherwise identical. Transfusion guidelines were uniformly applied to all patients. RESULTS An average volume of 1,540 +/- 302 mL of fresh autologous blood was removed and reinfused in the IAD group. Postoperative hematocrits were significantly greater at 12 and 24 hours postoperatively in the IAD group versus the control group despite a significant decrease in both the percentage of patients in whom allogeneic red blood cells were transfused (17% versus 52%; p < 0.01) and the number of red blood cell units transfused per patient per group (0.28 +/- 0.66 and 1.14 +/- 1.19 units; p < 0.01). Conversely, chest tube output, incidence of excessive postoperative bleeding, postoperative prothrombin time, and platelet and coagulation factor transfusion requirement did not differ between groups. CONCLUSIONS These results indicate that intraoperative autologous donation serves to preserve red blood cell mass. Its routine use in eligible patients is therefore justified. However, the removal and reinfusion of an individually calculated maximum volume of fresh autologous blood had no effect on postoperative bleeding or platelet and coagulation factor transfusion requirement. This lack of hemostatic effect belies the beliefs of many about the primary action of IAD, helps to delineate the optimal way in which to perform IAD, and carries implications regarding the use of allogeneic platelet and coagulation factors for the treatment of early postoperative bleeding.

Thyroid Hormone Therapy in Cardiovascular Disease

The relationship between thyroid disease states and cardiovascular hemodynamics is well recognized. Although the long-term effects of thyroid hormone are thought to result from changes in myocardial gene expression, attention has recently focused on acute, non-nuclear-mediated actions of L-triidothyronine (T3), the biologically active form of the hormone. Various lines of evidence have documented that T3 can act as a vasodilator and inotrope. With this recognition have come novel treatment strategies targeted at specific clinical conditions including heart failure and cardiac surgery that are associated with impaired cardiovascular performance and low serum T3 levels. An understanding of the mechanisms of action of thyroid hormone on the heart and peripheral vasculature is essential for the rational implementation of thyroid hormone as a therapeutic agent. As outlined in this review, initial clinical experience suggests that the ability of thyroid hormone to increase cardiac output and to lower systemic vascular resistance may provide a novel treatment option for physicians caring for patients with cardiovascular illness.

Thyroid Hormone and Cardiac Surgery

Thyroid hormone has important effects on the heart and peripheral vascular system. The relationship between thyroid disease states and cardiovascular hemodynamics is well recognized. Diverse clinical situations are associated with low serum triiodothyronine (T3) levels including a number of cardiovascular illnesses. In particular, cardiopulmonary bypass and open heart operations result in a low T3 state and are often complicated by significant cardiovascular dysfunction similar to that observed in clinical hypothyroidism. Multiple lines of evidence have suggested that T3 can act acutely as a positive inotrope and vasodilator agent. This recognition has prompted a number of investigators to study the effects of T3 administration to patients in the perioperative period. This paper reviews the experimental background that supported such clinical trials as well as outlines the results that have been documented in both adult and pediatric patients undergoing cardiac surgery. Low serum T3 levels resulting from cardiopulmonary bypass can be safely reversed with pharmacologic T3 supplementation. Data have suggested that T3 repletion may improve postoperative hemodynamic performance and lower the incidence of arrythmias. However, beneficial effects on major clinical outcome variables have not yet been conclusively demonstrated, and require future large-scale clinical trials.

Accepted but unacceptable: peripheral IV catheter failure.

Peripheral intravenous (IV) catheter insertion, the most common invasive hospital procedure performed worldwide, is associated with a variety of complications and an unacceptably high overall failure rate of 35% to 50% in even the best of hands. Catheter failure is costly to patients, caregivers, and the health care system. Although advances have been made, analysis of the mechanisms underlying the persistent high rate of peripheral IV failure reveals opportunities for improvement.

A multicenter comparison of intraaortic balloon pump utilization in isolated coronary artery bypass graft surgery

BACKGROUND Single-center studies suggest substantial variation in intraaortic balloon pump (IABP) utilization. Our purpose is to examine IABP utilization over time and across medical centers. METHODS This was a prospective cohort of 29,961 consecutive patients undergoing isolated coronary artery bypass graft surgery, between 1995 and 2000, at 10 centers (eight in northern New England and two in Canada). RESULTS A total of 2,678 (8.9%) patients received an IABP. The rate of preoperative IABP insertion was 6.3%, and that of intra- or postoperative insertion was 2.6%. During the 6 years, IABP use increased from 7.0% to 10.3% (p(trend) <0.001). Preoperative IABP insertion increased from 5.4% to 7.8% (p(trend) < 0.001). There was no significant increase in intra-/postoperative IABP insertion 1.7% to 3.4% (p(trend) = 0.34). Adjustment for changes in patient and disease characteristics did not substantially alter these results. The rate of IABP use varied substantially by center, from 5.9% to 16.4% (p < 0.001). Adjustment for patient and disease characteristics resulted in variation from 4.8% to 12.8% across the 10 centers (p < 0.001). The adjusted rates of preoperative IABP insertion varied from 3.6% to 13.7% (p < 0.001), and the rates of intra-/postoperative IABP insertion ranged from 1.0% to 5.2% (p < 0.001). There was no significant correlation between the rates of preoperative and intra-/postoperative IABP use (r(s) = 0.085, p = 0.815). CONCLUSIONS During the 6 years, there was a 47% increase in the rate of IABP utilization. Even after adjustment, there was almost threefold variation in IABP use across centers. This variation likely reflects lack of consensus on the appropriate use of the IABP in CABG patients.