Intrapericardial Left Ventricular Assist Device for Advanced Heart Failure.

BACKGROUND: Mechanical circulatory support with a left ventricular assist device (LVAD) is an established treatment for patients with advanced heart failure. We compared a newer LVAD design (a small intrapericardial centrifugal-flow device) against existing technology (a commercially available axial-flow device) in patients with advanced heart failure who were ineligible for heart transplantation. METHODS: We conducted a multicenter randomized trial involving 446 patients who were assigned, in a 2:1 ratio, to the study (centrifugal-flow) device or the control (axial-flow) device. Adults who met contemporary criteria for LVAD implantation for permanent use were eligible to participate in the trial. The primary end point was survival at 2 years free from disabling stroke or device removal for malfunction or failure. The trial was powered to show noninferiority with a margin of 15 percentage points. RESULTS: The intention-to treat-population included 297 participants assigned to the study device and 148 participants assigned to the control device. The primary end point was achieved in 164 patients in the study group and 85 patients in the control group. The analysis of the primary end point showed noninferiority of the study device relative to the control device (estimated success rates, 55.4% and 59.1%, respectively, calculated by the Weibull model; absolute difference, 3.7 percentage points; 95% upper confidence limit, 12.56 percentage points; P=0.01 for noninferiority). More patients in the control group than in the study group had device malfunction or device failure requiring replacement (16.2% vs. 8.8%), and more patients in the study group had strokes (29.7% vs. 12.1%). Quality of life and functional capacity improved to a similar degree in the two groups. CONCLUSIONS: In this trial involving patients with advanced heart failure who were ineligible for heart transplantation, a small, intrapericardial, centrifugal-flow LVAD was found to be noninferior to an axial-flow LVAD with respect to survival free from disabling stroke or device removal for malfunction or failure. (Funded by HeartWare; ENDURANCE ClinicalTrials.gov number, NCT01166347 .).

Patients Awaiting Heart Transplantation on HVAD Support for Greater Than 2 Years.

Advanced heart failure patients who are classified as bridge to transplant (BTT) often remain on mechanical circulatory support (MCS) for long durations because of the limited supply of donor organs. Here, we present the outcomes of patients who have been supported by the HeartWare ventricular assist device system for more than 2 years. In the HeartWare BTT and continued access protocol trial, 74 of the 382 total patients (19.4%) had more than 2 years of MCS with a mean time of 1,045 days on device. The long-term group was more frequently female, was nonwhite, and had Interagency Registry for Mechanically Assisted Circulatory Support profiles 4-7. Postimplant adverse event rates including bleeding, cardiac arrhythmia, infection, stroke, renal dysfunction, and right heart failure were less frequent in the long-term cohort. In addition, the long-term cohort displayed significant improvements in Kansas City Cardiomyopathy Questionnaire Overall Summary Score, EuroQOL-5D Overall Health State Score, and 6 minute walk scores from baseline values. The rate of heart transplantation was lower for the long-term cohort, which may have been a result of their sex and blood type. However, most of these patients are still listed for cardiac transplantation and maintained their quality of life profiles through 3 years of support.

An analysis of pump thrombus events in patients in the HeartWare ADVANCE bridge to transplant and continued access protocol trial.

BACKGROUND: The HeartWare left ventricular assist device (HVAD, HeartWare Inc, Framingham, MA) is the first implantable centrifugal continuous-flow pump approved for use as a bridge to transplantation. An infrequent but serious adverse event of LVAD support is thrombus ingestion or formation in the pump. In this study, we analyze the incidence of pump thrombus, evaluate the comparative effectiveness of various treatment strategies, and examine factors pre-disposing to the development of pump thrombus. METHODS: The analysis included 382 patients who underwent implantation of the HVAD as part of the HeartWare Bridge to Transplant (BTT) and subsequent Continued Access Protocol (CAP) trial. Descriptive statistics and group comparisons were generated to analyze baseline characteristics, incidence of pump thrombus, and treatment outcomes. A multivariate analysis was performed to assess significant risk factors for developing pump thrombus. RESULTS: There were 34 pump thrombus events observed in 31 patients (8.1% of the cohort) for a rate of 0.08 events per patient-year. The incidence of pump thrombus did not differ between BTT and CAP. Medical management of pump thrombus was attempted in 30 cases, and was successful in 15 (50%). A total of 16 patients underwent pump exchange, and 2 underwent urgent transplantation. Five patients with a pump thrombus died after medical therapy failed, 4 of whom also underwent a pump exchange. Survival at 1 year in patients with and without a pump thrombus was 69.4% and 85.5%, respectively (p = 0.21). A multivariable analysis revealed that significant risk factors for pump thrombus included a mean arterial pressure > 90 mm Hg, aspirin dose ≤ 81 mg, international normalized ratio ≤ 2, and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile level of ≥ 3 at implant. CONCLUSIONS: Pump thrombus is a clinically important adverse event in patients receiving an HVAD, occurring at a rate of 0.08 events per patient-year. Significant risk factors for pump thrombosis include elevated blood pressure and sub-optimal anti-coagulation and anti-platelet therapies. This suggests that pump thrombus event rates could be reduced through careful adherence to patient management guidelines.

Left ventricular assist device management in the ICU.

OBJECTIVES: To review left ventricular assist device physiology, initial postoperative management, common complications, trouble shooting and management of hypotension, and other common ICU problems. DATA SOURCE: Narrative review of relevant medical literature. DATA SYNTHESIS: Left ventricular assist devices prolong the lives of patients with end-stage heart failure, and their use is increasing. Continuous-flow left ventricular assist devices have replaced first-generation pulsatile devices. These patients present unique management concerns. In the immediate postimplant period, care must be taken to support the unassisted right ventricle. Invasive monitors for blood pressure, pulmonary artery catheterization, and echocardiography are essential to optimize left ventricular assist device settings and cardiac performance. Anticoagulation is necessary to prevent devastating thrombotic and embolic complications, but bleeding is a major source of morbidity due to inherent bleeding diatheses and prescribed anticoagulants. Infection of the device can be life threatening, and all infections must be aggressively treated to avoid seeding the device. Patients are at risk of ventricular arrhythmias because of their underlying disease, as well as the placement and position of the inflow cannula. Aortic valve stenosis and insufficiency develop over time and can lead to thrombosis or heart failure. Cardiopulmonary resuscitation with chest compressions must be performed with care or not at all due to risk of dislodging the device. CONCLUSION: Intensivists are increasingly likely to encounter patients requiring mechanical circulatory support with left ventricular assist devices at various points in the trajectory of their disease, from the immediate postimplant period to subsequent admissions for complications, and at end of life. A basic understanding of left ventricular assist device physiology is essential to the safe and effective care of these patients.

Current status of left ventricular assist device technology.

The use of long-term left ventricular assist devices (LVADs) has revolutionized the treatment of end-stage heart failure. The most significant advance in this field has been the longer durability of devices secondary to a simpler pump design with fewer or no mechanical bearings and valves. Continuous-flow LVADs have recently been shown to provide safe and effective circulatory support and have replaced the first-generation fill-to-empty devices. The Thoratec HeartMate II and the HeartWare HVAD are currently the 2 most commonly implanted LVADs worldwide. As LVAD technology moves forward and new miniaturized, more durable, and reliable pumps are being developed, the number of recipients who will benefit from this technology continues to grow. Elimination of the driveline with fully implantable pumps, implantation of miniature pumps with minimally invasive surgical techniques, wireless data transmission, and improved patient selection will further transform this field in the next few years.

HeartWare ventricular assist system for bridge to transplant: combined results of the bridge to transplant and continued access protocol trial.

BACKGROUND: The HeartWare Ventricular Assist System (HeartWare Inc, Framingmam, MA) is a miniaturized implantable, centrifugal design, continuous-flow blood pump. The pivotal bridge to transplant and continued access protocols trials have enrolled patients with advanced heart failure in a bridge-to-transplant indication. METHODS: The primary outcome, success, was defined as survival on the originally implanted device, transplant, or explant for ventricular recovery at 180 days. Secondary outcomes included an evaluation of survival, functional and quality of life outcomes, and adverse events. RESULTS: A total of 332 patients in the pivotal bridge to transplant and continued access protocols trial have completed their 180-day primary end-point assessment. Survival in patients receiving the HeartWare pump was 91% at 180 days and 84% at 360 days. Quality of life scores improved significantly, and adverse event rates remain low. CONCLUSIONS: The use of the HeartWare pump as a bridge to transplant continues to demonstrate a high 180-day survival rate despite a low rate of transplant. Adverse event rates are similar or better than those observed in historical bridge-to-transplant trials, despite longer exposure times due to longer survival and lower transplant rates.

Relationship between routine multi-detector cardiac computed tomographic angiography prior to reoperative cardiac surgery, length of stay, and hospital charges.

While multi-detector cardiac computed tomography angiography (MDCCTA) prior to reoperative cardiac surgery (RCS) has been associated with improved clinical outcomes, its impact on hospital charges and length of stay remains unclear. We studied 364 patients undergoing RCS at Washington Hospital Center between 2004 and 2008, including 137 clinically referred for MDCCTA. Baseline demographics, procedural data, and perioperative outcomes were recorded at the time of the procedure. The primary clinical endpoint was the composite of perioperative death, myocardial infarction (MI), stroke, and hemorrhage-related reoperation. Secondary clinical endpoints included surgical procedural variables and the perioperative volume of bleeding and transfusion. Length of stay was determined using the hospital's electronic medical record. Cost data were extracted from the hospital's billing summary. Analysis was performed on individual categories of care, as well as on total hospital charges. Data were compared between subjects with and without MDCCTA, after adjustment for the Society of Thoracic Surgeons score. Baseline characteristics were similar between the two groups. MDCCTA was associated with shorter procedural times, shorter intensive care unit stays, fewer blood transfusions, and less frequent perioperative MI. There was additionally a trend towards a lower incidence of the primary endpoint (17.5 vs. 24.2 %, p = 0.13) primarily due to a lower incidence of perioperative MI (0 vs. 5.7 %, p = 0.002). MDCCTA was also associated with lower median recovery room [$1,325 (1,250-3,302) vs. $3,217 (1,325-5,353) p < 0.001] and nursing charges [$6,335 (3,623-10,478) vs. $6,916 (3,915-14,499) p = 0.03], although operating room charges were higher [$24,100 (22,300-29,700) vs. $23,500 (19,900-27,700) p < 0.05]. Median total charges [$127,000 (95,000-188,000) vs. $123,000 (86,800-226,000) p = 0.77] and length of stay [9 days (6-19) vs. 11 days (7-19), p = 0.21] were similar. Means analysis demonstrated a strong trend towards lower mean total hospital charges [$163,000 (108,426) vs. $192,000 (181,706), p = 0.06] in the MDCCTA group. In conclusion, preoperative MDCCTA is associated with a number of improved perioperative outcomes and does not significantly effect the length of stay or total hospital charges during the index hospitalization.

Use of an intrapericardial, continuous-flow, centrifugal pump in patients awaiting heart transplantation.

BACKGROUND: Contemporary ventricular assist device therapy results in a high rate of successful heart transplantation but is associated with bleeding, infections, and other complications. Further reductions in pump size, centrifugal design, and intrapericardial positioning may reduce complications and improve outcomes. METHODS AND RESULTS: We studied a small, intrapericardially positioned, continuous-flow centrifugal pump in patients requiring an implanted ventricular assist device as a bridge to heart transplantation. The course of investigational pump recipients was compared with that of patients implanted contemporaneously with commercially available devices. The primary outcome, success, was defined as survival on the originally implanted device, transplantation, or explantation for ventricular recovery at 180 days and was evaluated for both noninferiority and superiority. Secondary outcomes included a comparison of survival between groups and functional and quality-of-life outcomes and adverse events in the investigational device group. A total of 140 patients received the investigational pump, and 499 patients received a commercially available pump implanted contemporaneously. Success occurred in 90.7% of investigational pump patients and 90.1% of controls, establishing the noninferiority of the investigational pump (P<0.001; 15% noninferiority margin). At 6 months, median 6-minute walk distance improved by 128.5 m, and both disease-specific and global quality-of-life scores improved significantly. CONCLUSIONS: A small, intrapericardially positioned, continuous-flow, centrifugal pump was noninferior to contemporaneously implanted, commercially available ventricular assist devices. Functional capacity and quality of life improved markedly, and the adverse event profile was favorable. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00751972.

Fluoroscopy use and left anterior descending artery angiography to guide transapical access in patients with prior cardiac surgery.

BACKGROUND: Patients with severe aortic stenosis (AS) and prior cardiac surgery undergoing aortic valve replacement (AVR) are at high risk. Transapical AVR might reduce the risk in patients not suitable for the transfemoral approach. We aimed to describe the fluoroscopy and left anterior descending artery (LAD) angiography guidance technique for transapical AVR access and the initial related procedural results. METHODS: Patients with severe AS and prior cardiac surgery undergoing transapical AVR using LAD angiographic-guided apical puncture were analyzed (n=9). Additional guidance was added to the standard technique as follows. Minithoracotomy was performed at the level of the intercostal space in closer relationship to the apex identified by fluoroscopy. LAD angiography was performed at the time that the area of interest was recognized by radiopaque marker to ensure puncture lateral to the LAD. Apical needle puncture was performed under fluoroscopy guidance directed towards the aortic root. RESULTS: The population had a mean age of 83 years and was more frequently male (89%) with a high-risk profile (mean Society of Thoracic Surgeons score of 11%). Two patients received the 23-mm Edwards SAPIEN valve, and seven patients received the 26-mm SAPIEN device. All nine patients underwent successful implantation of transcatheter aortic valves with virtual abolishment of transaortic gradient, without procedural complications. CONCLUSION: Fluoroscopy and angiography for guidance of the transapical approach facilitate a safe and rapid access to the apex, insuring no risk of damage to the LAD or to large diagonals.

Patients with severe asymptomatic carotid artery stenosis do not have a higher risk of stroke and mortality after coronary artery bypass surgery.

BACKGROUND AND PURPOSE: Stroke development is a major concern in patients undergoing coronary artery bypass grafting (CABG). Whether asymptomatic severe carotid artery stenosis (CAS) contributes to the development of stroke and mortality in such patients remains uncertain. METHODS: A retrospective analysis of 878 consecutive patients with documented carotid duplex ultrasound who underwent isolated CABG in our institution from January 2003 to December 2009 was performed. Patients with severe CAS (n=117) were compared with those without severe CAS (n=761) to assess the rates of stroke and mortality during hospitalization for CABG. The 30-day mortality rate was also assessed. RESULTS: Patients with severe CAS were older and had a higher prevalence of peripheral arterial disease and heart failure. Patients with severe CAS had similar rates of in-hospital stroke (3.4% versus 3.6%; P=1.0) and mortality (3.4% versus 4.2%; P=1.0) compared with patients without severe CAS. The 30-day rate of mortality was also similar between the 2 cohorts (3.4% versus 2.9%; P=0.51). CONCLUSIONS: Severe CAS alone is not a risk factor for stroke or mortality in patients undergoing CABG. The decision to perform carotid imaging and subsequent revascularization in association with CABG must be individualized and based on clinical judgment.

Comparison of frequency of atrial fibrillation after coronary artery bypass grafting in African Americans versus European Americans.

In the general population, African Americans experience atrial fibrillation (AF) less frequently than European Americans. This difference could also exist in the incidence of this arrhythmia after cardiac surgery, but this possibility has been insufficiently examined. To test the association of such an ethnic difference, we compared the incidence of postoperative AF in a consecutive series of 2,312 African Americans and 6,054 European Americans who underwent isolated coronary artery bypass grafting from July 2000 to June 2007. Raw differences between the cohorts in the incidence of new AF were adjusted to take into account the baseline differences. Postoperatively, new-onset AF developed in 504 (22%) of 2,312 African-American patients and in 1,838 (30%) of 6,054 European-American patients (p <0.01). After adjustment with logistic regression analysis for numerous baseline differences, African Americans remained less likely to develop AF (odds ratio 0.63, 95% confidence interval 0.55 to 0.72; p <0.001). Risk was also adjusted using propensity matching. In that analysis, 457 (22%) of 2,059 African-American patients had postoperative AF, as did 597 (29%) of 2,059 matched European-American patients (p <0.01). In conclusion, AF was significantly less common among African-American patients than among European-American patients after coronary artery bypass grafting.

Association of body mass index with new-onset atrial fibrillation after coronary artery bypass grafting operations.

BACKGROUND: Postoperative atrial fibrillation (AF) frequently complicates coronary artery bypass grafting (CABG) operations. As the frequency of obesity has increased in the United States, the number of obese patients undergoing CABG has kept pace. This study sought to define the association between body mass index (BMI) and postoperative AF. METHODS: We studied 12,367 consecutive patients with no history of AF who underwent isolated CABG operations. BMI was stratified according to Centers for Disease Control and Prevention criteria, and differences in baseline clinical and operative characteristics were adjusted through multivariate logistic regression models. RESULTS: The unadjusted incidence of new-onset postoperative AF demonstrated a U-shape with regard to BMI. The highest incidence (34%) was found in the "lean" stratum (BMI<18.5 kg/m2), followed by 32% in the "severely obese" (BMI≥40 kg/m2) stratum. Lower incidences were found in the "normal" stratum (30%), in the "obese" stratum (28%), and the lowest incidence (26%) was in the overweight stratum. Observed incidence was 50% greater than the expected incidence in the "severely obese" stratum (32% vs 21%). In multivariate regression analysis adjusted for age and other covariates, BMI remains a strong risk factor for new-onset postoperative AF. Compared with normal BMI, obesity (odds ratio, 1.24; 95% confidence interval, 1.08 to 1.42) and severe obesity (odds ratio, 2.00; 95% confidence interval, 1.54 to 2.57) both emerged as strong risk factors for postoperative AF. No association was found between a lean BMI and postoperative AF (odds ratio, 1.14; 95% confidence interval, 0.66 to 1.98). CONCLUSIONS: After adjusting for potential confounders, obesity, as reflected by the body mass index, remains an independent predictor of postoperative AF.

Is vasoplegic syndrome more prevalent with open-heart procedures compared with isolated on-pump CABG surgery?

Postoperative vasoplegic syndrome (PVS) is a frequent complication and can affect the early postoperative course. Our study investigated the incidence and risk factors of PVS after on-pump isolated coronary artery grafting bypass (CABG) and on-pump open-heart surgery. A total of 629 patients underwent on-pump cardiac surgery from November 21, 2005, to June 9, 2006, at our institution. Of those, 334 patients underwent on-pump isolated CABG and 295 patients had open-heart surgery. PVS was defined based on the recognized criteria. Multivariate logistic regression analysis was used to identify the risk factors for PVS. The overall incidence of PVS was 11.7%. The incidence in isolated on-pump CABG surgery was 6.9% and 17.0% in open-heart surgery (P<.01). In multivariate analysis, isolated CABG reduced by half the incidence of PVS [odds ratio (OR)=0.45, P=.02]; preoperative left ventricular ejection fraction (EF) <35% was identified as an independent predictor of PVS (OR=2.1, P=.01), and a protective effect of female gender for PVS was observed (OR=0.4, P=.01). The association between angiotensin-converting enzyme inhibitors and other preoperative medical treatments was not confirmed by our study. In conclusion, PVS occurred less often after isolated CABG surgery than after open-heart surgery. Advanced age and low preoperative EF strongly predicted PVS.

A randomized, open-label pilot study comparing desirudin and argatroban in patients with suspected heparin-induced thrombocytopenia with or without thrombosis: PREVENT-HIT Study.

Because of an extreme risk for thromboemboli, patients with suspected heparin-induced thrombocytopenia (HIT) require immediate initiation of an alternative anticoagulant. The only therapies approved by the Food and Drug Administration require intravenous infusion of expensive direct thrombin inhibitors. This prospective, randomized, open-label, exploratory study compared the clinical and economic utility of subcutaneous desirudin vs argatroban, the most frequently used agent for suspected or immunologically confirmed HIT, with or without thrombosis. Sixteen patients were randomized to treatment with fixed-dose desirudin (15 or 30 mg) every 12 hours or activated partial thromboplastin time-adjusted argatroban by intravenous infusion. Arm A included 8 patients naive to direct thrombin inhibitor therapy, whereas Arm B included 8 patients on argatroban for at least 24 hours before randomization. The primary efficacy measure was the composite of new or worsening thrombosis (objectively documented), amputation, or death. Other end points included major and minor bleeding while on drug therapy, time to platelet count recovery, and pharmacoeconomics. No amputations or deaths occurred. One patient randomized to argatroban had worsening of an existing thrombosis. Major bleeding occurred in 2 patients on argatroban and in none during desirudin treatment. There was 1 minor bleed in each treatment group. The average medication cost per course of treatment was $1688 for desirudin and $8250 for argatroban. Desirudin warrants further study as a potentially cost-effective alternative to argatroban in patients with suspected HIT.

Perioperative outcomes in reoperative cardiac surgery guided by cardiac multidetector computed tomographic angiography.

BACKGROUND: Preoperative evaluation with contrast-enhanced multidetector computed tomographic angiography (MDCTA) is considered an "appropriate" indication based on expert consensus. We aimed to evaluate how the presurgical evaluation with MDCTA impacts the outcomes after reoperative cardiac surgery (RCS). METHODS: We retrospectively studied 364 patients undergoing RCS between 2004 and 2008, including 137 referred for MDCTA. High-risk CT findings were defined as the presence of right ventricle or aorta <10 mm from the sternum or a bypass graft <10 mm from the sternum crossing the midline. The primary clinical end point was the composite of perioperative death, myocardial infarction (MI), stoke, and hemorrhage-related reoperation. Secondary end points included surgical procedural variables and the perioperative volume of bleeding and of red blood cell (RBC) transfusion. RESULTS: Baseline clinical characteristics were similar between the 2 groups. Individuals referred for MDCTA showed a trend toward a lower incidence of the composite primary end point (17.5% vs 24.2%, P = .13), primarily related to a significantly lower incidence of perioperative MI (0% vs 5.7%, P = .002). Multidetector computed tomographic angiography was also associated with shorter perfusion (90 vs 110 minutes, P = .002), cross clamp time (63 vs 75 minutes, P = .003), and total time in intensive care unit (103 vs 148 hours, P = .04), and a lower volume of postoperative RBC transfusion (627 vs 824 mL, P = .09). These differences remained significant after adjustment for the Society of Thoracic Surgeons score and the performing surgeon. CONCLUSION: The use of MDCTA before RCS was associated with shorter perfusion and cross clamp time, shorter intensive care unit stays, and less frequent perioperative MI.

Off-pump coronary artery bypass grafting improves in-hospital mortality in patients with dialysis-dependent renal failure.

OBJECTIVE: Patients with chronic dialysis-dependent end-stage renal disease are increasingly referred for coronary artery bypass grafting (CABG) and their early outcome is less favorable. Off-pump CABG (OPCAB) has achieved encouraging results in high-risk patients. Therefore, we designed this retrospective study to test the hypothesis that OPCAB reduced surgical risks in dialysis patients. METHODS: From January 2000 to December 2005, 294 dialysis-dependent patients received isolated CABG at the Washington Hospital Center. Among them, 168 underwent OPCAB (off-pump group), and 126, CABG with cardiopulmonary bypass (CPB) (on-pump group). The in-hospital outcomes were analyzed. RESULTS: The two groups were comparable in terms of preoperative characteristics. The Parsonnet's Bedside Score of the off-pump group was similar to that of the on-pump group (32.0 vs. 32.0, P=.57). The in-hospital mortality of the off-pump group was significantly lower than that of the on-pump group (5.4% vs. 11.9%, P=.04). Although the percentage of patients who received transfusions was similar, the on-pump group received more total transfusions. Logistic regression analysis revealed that use of CPB independently predicted in-hospital mortality [odds ratio (OR), 5.0; 95% confidence interval, 1.78-13.85; P<.01] and perioperative myocardial infarction (MI; OR, 5.1; 95% confidence interval, 1.18-22.40; P=.03). No significant difference in long-term survival at 4 years was absorbed between the two groups of hospital survivors. CONCLUSIONS: Our data suggest that OPCAB is a safe alternative to on-pump CABG in dialysis patients. Avoiding CPB resulted in less perioperative blood utilization, MI, and hospital mortality.

Is cardiac surgery safe in extremely obese patients (body mass index 50 or greater)?

BACKGROUND: We investigated the impact of extreme obesity (body mass index [kg/m(2)] 50 or greater) on short-term clinical outcomes and report 1-year mortality. METHODS: Fifty-seven patients were found to have a body mass index of 50 or greater among 14,449 patients who underwent cardiac surgery between July 2000 and June 2007. Multivariable logistic regression analyses were used to assess the independent influence of extreme obesity on the major outcomes. RESULTS: Of the 57 patients, the mean age was 58 +/- 11 years, mean body mass index was 55.1, and 63% of the patients were women. Forty patients underwent elective surgery. Forty-one patients had isolated coronary artery bypass graft surgery. The overall operative mortality was 9%; the mortality was 5% in isolated coronary artery bypass graft surgery and 5% in elective surgery. Fifteen patients had nonelective isolated coronary artery bypass graft surgery, and 2 patients had emergent active endocarditis surgery. Off-pump coronary artery bypass graft surgery was performed on 23 patients (23 of 41, 54%). After adjusting for known preoperative and operative risk factors through a multivariate logistic model, extreme obesity did not emerge as a significant risk factor for operative mortality (odds ratio, 1.75; p = 0.47) and other adverse outcomes (p > 0.05) after elective surgery; however, extreme obesity was marginally associated with increased mortality (odds ratio, 2.69; p = 0.05) and was a risk predictor for longer intensive care unit stays (odds ratio, 2.43; p = 0.01) in overall surgery. The 1-year survival rate was 82.5%. CONCLUSIONS: Extreme obesity is not a contraindication to elective cardiac surgery. Studies stratifying the risk factors of mortality for nonelective surgery in extremely obese patients may be warranted.

Early readmission of low-risk patients after coronary surgery.

BACKGROUND: Early readmission after coronary artery bypass grafting (CABG) is an expensive adverse outcome. Although the perioperative experience of high-risk CABG patients has been studied extensively, little attention has been paid to low-risk CABG patients. The primary goal of this study was to identify the preoperative characteristics and to define risk predictors of readmission and preventive factors for readmission in low-risk isolated-CABG patients. METHODS: We identified 2157 patients who underwent CABG between January 2000 and December 2005 at Washington Hospital Center, Washington, DC, and defined as low risk patients who had a Parsonnet bedside risk score lower than the 25th percentile. Patients who were rehospitalized within 30 days after surgery were compared with those who were not rehospitalized during this period. RESULTS: The overall readmission rate for this study cohort was 6.3%. Compared with non-readmitted patients, early-readmitted patients were more likely to have diabetes mellitus (27.94% versus 20.88%, P = .05) and less likely to have hypertension (42.65% versus 51.36%, P = .05). Blood product transfusion (P < .01), postoperative length of intensive care unit stay (P = .01), and length of hospital stay (P = .05) were all significantly increased in the readmitted patients. The use of beta-blockers (P = .03) and angiotensin-converting enzyme inhibitors (P = .04) was significantly lower at discharge in this group of patients; however, multivariate regression analysis demonstrated diabetes (odds ratio, 1.59; 95% confidence interval, 1.08-2.42) to be the only independent predictor of early readmission. CONCLUSIONS: For low-risk CABG patients, diabetes mellitus is the risk predictor of early readmission. Early discharge was not associated with early readmission.