Pump thrombosis remains an uncommon but potentially catastrophic complication of durable continuous-flow left ventricular assist devices (LVAD). A perceived increase in the incidence of pump ...thrombosis in the HeartMate II (HMII) LVAD (Thoratec, Pleasanton, CA) by clinicians prompted this analysis of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database.
Between 2006 and June 2013, 8,988 United States patients aged older than 18 years received a durable LVAD. Of these, 6,910 adult patients from 132 institutions who received a HMII LVAD were entered in the INTERMACS database and constitute the study group for this analysis.
Overall survival (with censoring at transplant or explant for recovery) with the HMII LVAD was 80% at 1 year and 69% at 2 years and was not significantly different when stratified by era of implant. Freedom from device exchange or death due to thrombosis decreased from 99% at 6 months in 2009 to 94% in 2012 (p < 0.0001). Multivariable hazard function analysis showed risk factors for pump thrombosis included later implant year (p < 0.0001), younger age (p < 0.0001), higher creatinine (p = 0.002), larger body mass index (p = 0.004), white race (p = 0.0004), left ventricular ejection fraction above 20% (p = 0.02), and higher lactate dehydrogenase level at 1 month (p < 0.0001). Survival (p < 0.0001) and freedom from infection (p = 0.008) and cerebrovascular accident (p < 0.0001) were lower after pump exchange than after primary implant.
Pump exchange or death due to pump thrombosis increased during 2011 and 2012, but the magnitude of the increase remained relatively small. Survival remains high (80% at 1 year) with the HMII LVAD. Risk factor analysis suggests that a number of patient-related factors contribute to the risk of thrombosis. Markedly elevated lactate dehydrogenase in the first month is a predictor of pump thrombosis. This analysis could not examine the potential role of technical factors during implant, such as sub-optimal pump or graft positioning, changes in patient management paradigms with pump speed settings, improved recognition and change in the threshold for pump exchange, or design or production changes with the pump, as contributors to the risk of pump thrombosis.
This study evaluates contemporary trends in the use and outcomes of adult patients undergoing extracorporeal membrane oxygenation (ECMO) in U.S. hospitals. All adult discharges in the Nationwide ...Inpatient Sample database during the years 2002-2012 that included ECMO were used to estimate the total number of U.S. ECMO hospitalizations ( n = 12,407). Diagnostic codes were used to group patients by indication for ECMO use into postcardiotomy, heart transplant, lung transplant, cardiogenic shock, respiratory failure, and cardiopulmonary failure. A Mann-Kendall test was used to examine trends over time using standard statistical techniques for survey data. We found that ECMO use increased significantly from 2002-2012 ( P = 0.003), whereas in-hospital mortality rate fluctuated without a significant difference in trend over time. No significant trend was observed in overall ECMO use from 2002-2007, but the use did demonstrate a statistically significant increase from 2007-2012 ( P = 0.0028). The highest in-hospital mortality rates were found in the postcardiotomy (57.2%) and respiratory failure (59.2%) groups. Lung and heart transplant groups had the lowest in-hospital mortality rates (44.10% and 45.31%, respectively). The proportion of ECMO use for postcardiotomy decreased from 56.9% in 2002 to 37.9% in 2012 ( P = 0.026) and increased for cardiopulmonary failure from 3.9% to 11.1% ( P = 0.026). We concluded that ECMO use in the United States increased between 2002 and 2012, driven primarily by increase in national ECMO use beginning in 2007. Mortality rates remained high but stable during this time period. Though there were shifts in relative ECMO use among patient groups, absolute ECMO use increased for all indications over the study period.
Abstract Background Infections are the most common noncardiac complication after cardiac surgery, but their incidence across a broad range of operations, as well as the management factors that shape ...infection risk, remain unknown. Objectives This study sought to prospectively examine the frequency of post-operative infections and associated mortality, and modifiable management practices predictive of infections within 65 days from cardiac surgery. Methods This study enrolled 5,158 patients and analyzed independently adjudicated infections using a competing risk model (with death as the competing event). Results Nearly 5% of patients experienced major infections. Baseline characteristics associated with increased infection risk included chronic lung disease (hazard ratio HR: 1.66; 95% confidence interval CI: 1.21 to 2.26), heart failure (HR: 1.47; 95% CI: 1.11 to 1.95), and longer surgery (HR: 1.31; 95% CI: 1.21 to 1.41). Practices associated with reduced infection risk included prophylaxis with second-generation cephalosporins (HR: 0.70; 95% CI: 0.52 to 0.94), whereas post-operative antibiotic duration >48 h (HR: 1.92; 95% CI: 1.28 to 2.88), stress hyperglycemia (HR: 1.32; 95% CI: 1.01 to 1.73); intubation time of 24 to 48 h (HR: 1.49; 95% CI: 1.04 to 2.14); and ventilation >48 h (HR: 2.45; 95% CI: 1.66 to 3.63) were associated with increased risk. HRs for infection were similar with either <24 h or <48 h of antibiotic prophylaxis. There was a significant but differential effect of transfusion by surgery type (excluding left ventricular assist device procedures/transplant) (HR: 1.13; 95% CI: 1.07 to 1.20). Major infections substantially increased mortality (HR: 10.02; 95% CI: 6.12 to 16.39). Conclusions Major infections dramatically affect survival and readmissions. Second-generation cephalosporins were strongly associated with reduced major infection risk, but optimal duration of antibiotic prophylaxis requires further study. Given practice variations, considerable opportunities exist for improving outcomes and preventing readmissions. (Management Practices and Risk of Infection Following Cardiac Surgery; NCT01089712 )
Abstract Objectives The Cardiothoracic Surgical Trials Network recently reported no difference in the primary end point of left ventricular end-systolic volume index at 1 year postsurgery in patients ...randomized to repair (n = 126) or replacement (n = 125) for severe ischemic mitral regurgitation. However, patients undergoing repair experienced significantly more recurrent mitral regurgitation than patients undergoing replacement (32.6% vs 2.3%). We examined whether baseline echocardiographic and clinical characteristics could identify those who will develop moderate/severe recurrent mitral regurgitation or die. Methods Our analysis includes 116 patients who were randomized to and received mitral valve repair. Logistic regression was used to estimate a model-based probability of recurrence or death from baseline factors. Receiver operating characteristic curves were constructed from these estimated probabilities to determine classification cut-points maximizing accuracy of prediction based on sensitivity and specificity. Results Of the 116 patients, 6 received a replacement before leaving the operating room; all other patients had mild or less mitral regurgitation on intraoperative echocardiogram after repair. During the 2-year follow-up period, 76 patients developed moderate/severe mitral regurgitation or died (53 mitral regurgitation recurrences, 13 mitral regurgitation recurrences and death, and 10 deaths). The mechanism for recurrent mitral regurgitation was largely mitral valve leaflet tethering. Our model (including age, body mass index, sex, race, effective regurgitant orifice area, basal aneurysm/dyskinesis, New York Heart Association class, history of coronary artery bypass grafting, percutaneous coronary intervention, or ventricular arrhythmias) yielded an area under the receiver operating characteristic curve of 0.82. Conclusions The model demonstrated good discrimination in identifying patients who will survive 2 years without recurrent mitral regurgitation after mitral valve repair. Although our results require validation, they offer a clinically relevant risk score for selection of surgical candidates for this procedure.
In the era of destination continuous flow left ventricular assist devices (LVAD), the decision of whether a patient will tolerate isolated LVAD support or will need biventricular support (BIVAD) can ...be challenging. Incorrect decision making with delayed right ventricular (RV) assist device implantation results in increased morbidity and mortality. Continuous flow LVADs have been shown to decrease pulmonary hypertension and improve RV function. We undertook this study to determine predictors in the continuous flow LVAD era that identify patients who are candidates for isolated LVAD therapy as opposed to biventricular support.
We reviewed demographic, hemodynamic, laboratory, and echocardiographic variables for 218 patients who underwent VAD implant from 2003 through 2011 (LVAD=167, BIVAD=51), during the era of continuous flow LVADs.
Fifty preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BIVAD. Seventeen variables demonstrated statistical significance by univariate analysis. Multivariable logistic regression analysis identified central venous pressure>15 mmHg (OR 2.0, "C"), severe RV dysfunction (OR 3.7, "R"), preoperative intubation (OR 4.3, "I"), severe tricuspid regurgitation (OR 4.1, "T"), heart rate>100 (OR 2.0, Tachycardia-"T")-CRITT as the major criteria predictive of the need for biventricular support. Utilizing these data, a highly sensitive and easy to use risk score for determining RV failure was generated that outperformed other established risk stratification tools.
We present a preoperative risk calculator to determine suitability of a patient for isolated LVAD support in the current continuous flow ventricular assist device era.
Readmissions are a common problem in cardiac surgery. The goal of this study was to examine the frequency, timing, and associated risk factors for readmission after cardiac operations.
A 10-center ...cohort study prospectively enrolled 5,158 adult cardiac surgical patients (5,059 included in analysis) to assess risk factors for infection after cardiac operations. Data were also collected on all-cause readmissions occurring within 65 days after the operation. Major outcomes included the readmission rate stratified by procedure type, cause of readmission, length of readmission stay, and discharge disposition after readmission. Multivariable Cox regression was used to determine risk factors for time to first readmission.
The overall rate of readmission was 18.7% (number of readmissions, 945). When stratified by the most common procedure type, readmission rates were isolated coronary artery bypass grafting, 14.9% (n = 248); isolated valve, 18.3% (n = 337); and coronary artery bypass grafting plus valve, 25.0% (n = 169). The three most common causes of first readmission within 30 days were infection (17.1% n = 115), arrhythmia (17.1% n = 115), and volume overload (13.5% n = 91). More first readmissions occurred within 30 days (80.6% n = 672) than after 30 days (19.4% n = 162), and 50% of patients were readmitted within 22 days from the index operation. The median length of stay during the first readmission was 5 days. Discharge in 15.8% of readmitted patients (n = 128) was to a location other than home. Baseline patient characteristics associated with readmission included female gender, diabetes mellitus on medication, chronic obstructive pulmonary disease, elevated creatinine, lower hemoglobin, and longer operation time. More complex surgical procedures were associated with an increased risk of readmission compared with the coronary artery bypass grafting group.
Nearly 1 of 5 patients who undergo cardiac operations require readmission, an outcome with significant health and economic implications. Management practices to avert in-hospital infections, reduce postoperative arrhythmias, and avoid volume overload offer important targets for quality improvement.
Valve repair for ischemic mitral regurgitation (IMR) with undersized annuloplasty rings is characterized by high IMR recurrence rates. Patient-specific preoperative imaging-based risk stratification ...for recurrent IMR would optimize results. We sought to determine if prerepair three-dimensional (3D) echocardiography combined with a novel valve-modeling algorithm would be predictive of IMR recurrence 6 months after repair.
Intraoperative transesophageal real-time 3D echocardiography was performed in 50 patients undergoing undersized ring annuloplasty for IMR and in 21 patients with normal mitral valves. A customized image analysis protocol was used to assess 3D annular geometry and regional leaflet tethering. IMR recurrence (≥ grade 2) was assessed with two-dimensional transthoracic echocardiography 6 months after repair.
Preoperative annular geometry was similar in all IMR patients, and preoperative leaflet tethering was significantly higher in patients with recurrent IMR (n=13) than in patients in whom IMR did not recur (n=37) (tethering index: 3.91 ± 1.01 vs 2.90 ± 1.17, p = 0.008; tethering angles of A3: 23.5° ± 8.9° vs 14.4° ± 11.4°, p = 0.012; P2: 44.4° ± 8.8° vs 28.2° ± 17.0°, p = 0.002; and P3: 35.2° ± 6.0° vs. 18.6° ± 12.7°, p < 0.001). Multivariate logistic regression analysis revealed the preoperative P3 tethering angle as an independent predictor of IMR recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84 to 1.00; p < 0.001).
3D echocardiography combined with valve modeling is predictive of recurrent IMR. Preoperative regional leaflet tethering of segment P3 is a strong independent predictor of IMR recurrence after undersized ring annuloplasty. In patients with a preoperative P3 tethering angle of 29.9° or larger, chordal-sparing valve replacement rather than valve repair should be strongly considered.
Background Ischemic mitral regurgitation, a complication of myocardial infarction and coronary artery disease more generally, is associated with a high mortality rate and is estimated to affect 2.8 ...million Americans. With 1-year mortality rates as high as 40%, recent practice guidelines of professional societies recommend repair or replacement, but there remains a lack of conclusive evidence supporting either intervention. The choice between therapeutic options is characterized by the trade-off between reduced operative morbidity and mortality with repair versus a better long-term correction of mitral insufficiency with replacement. The long-term benefits of repair versus replacement remain unknown, which has led to significant variation in surgical practice. Methods and Results This article describes the design of a prospective randomized clinical trial to evaluate the safety and effectiveness of mitral valve repair and replacement in patients with severe ischemic mitral regurgitation. This trial is being conducted as part of the Cardiothoracic Surgical Trials Network. This article addresses challenges in selecting a feasible primary end point, characterizing the target population (including the degree of mitral regurgitation) and analytical challenges in this high mortality disease. Conclusions The article concludes by discussing the importance of information on functional status, survival, neurocognition, quality of life, and cardiac physiology in therapeutic decision making.
Pump thrombosis in durable continuous-flow pumps is a barrier to long-term mechanical circulatory support. Earlier Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data ...identified an increasing risk of pump thrombosis in recent years with the HeartMate II (HMII) left ventricular assist device. The current analysis examines pump thrombosis in the patient cohort extended through June 2014.
The INTERMACS identified 9,808 adult patients from 144 institutions receiving a primary HMII implant between April 2008 and June 30, 2014. Pump thrombosis was identified at time of explant, transplant or death. Risk factors for pump thrombosis were examined by multivariable analysis in the hazard function domain. The association between pump thrombosis and implant year was modeled in the hazard domain.
Parametric hazard modeling of thrombosis by year of implant identified an increasing risk of pump thrombosis from 2009 through 2013, followed by a decrease in the risk during the first half of 2014, which was most apparent during the first 3 months post-implant. Risk factors for pump thrombosis included younger age (p < 0.001), higher body mass index (p = 0.02), history of non-compliance (p = 0.004), severe right heart failure (p = 0.02), later date of implant (p < 0.0001), and elevated lactate dehydrogenase during the first month post-implant (p < 0.0001). Subsequent pump thrombosis was more likely if the initial pump exchange indication was pump thrombosis (p < 0.0001).
The small, but progressive increase in the incidence of pump thrombosis observed between 2010 and 2013 with the HMII pump had reversed somewhat in the first half of 2014. Identification of marked elevation of lactate dehydrogenase during the first month offers an opportunity for early intervention strategies.
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.
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.
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.
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.
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