Improved survival and decreasing incidence of adverse events with the HeartMate II left ventricular assist device as bridge-to-transplant therapy. Ann Thorac Surg. 2008;86:1227-1234. [PMID: 18805167 DOI: 10.1016/j.athoracsur.2008.06.030]

Changing outcomes in patients bridged to heart transplantation with continuous- versus pulsatile-flow ventricular assist devices: an analysis of the registry of the International Society for Heart and Lung Transplantation

BACKGROUND

Patients bridged to heart transplantation with left ventricular assist devices (LVADs) have been reported to have higher post-transplant mortality compared with those without LVADs. Our aim was to determine the impact of the type of LVAD and implant era on post-transplant survival.

METHODS

In this study we included 8,557 patients from the registry of the International Society for Heart and Lung Transplantation. We examined post-transplant outcomes in 1,100 patients bridged to transplant with pulsatile-flow LVADs between January 2000 and June 2004 (first era), 880 patients bridged with pulsatile-flow LVADs between July 2004 and May 2008 (second era), and 417 patients bridged with continuous-flow LVADs in the second era. Patients who required intravenous inotropes but not LVAD support (n = 2,728) and patients who did not require either LVAD or inotropes (n = 3,432) served as controls.

RESULTS

Post-transplant survival of patients bridged with pulsatile LVADs improved significantly between the first and the second era (p = 0.03). In the second era, there was no significant difference in post-transplant survival of patients bridged with pulsatile- vs continuous-flow LVADs (p = 0.26), and survival rates in the 2 groups were not statistically different from that of the non-LVAD group. Graft rejection was similar in patients bridged with LVADs compared to those without LVADs.

CONCLUSIONS

In the most recent era, the use of either pulsatile- or continuous-flow LVADs did not result in increased post-transplant mortality. This finding is important as the proportion of patients with LVADs at the time of transplant has been rising.

Driveline infections in patients supported with a HeartMate II: incidence, aetiology and outcome

OBJECTIVES

To investigate the incidence and outcome of driveline infections in patients supported with a continuous flow left ventricular assist device (HeartMate II (HMII)) and to study the microbiological aetiology.

DESIGN

Retrospective analysis of 31 patients who received an implantation of a HMII. Follow-up was from implantation to either device explantation, death or closure of the study. Clinical signs of infections were divided into superficial, deep or systemic and compared to culture and gram stain, the clinical course and infectious parameters.

RESULTS

The incidence of driveline infections was 1.65 episodes per patient per year. Staphylococcus aureus and Escherichia coli were the most common bacterial aetiology. More than two weeks of treatment was required in 81% of the patients. In terms of detecting superficial driveline infections, leucocyte count demonstrated a sensitivity of 27% and C-reactive protein (CRP) a sensitivity of 28%. In 22 cases of driveline infections plasma pro-calcitonin was found to be normal.

CONCLUSION

Driveline infections are common in HMII recipients but primarily remain superficial and are reasonably easy to manage. Infectious agents mostly originate from the skin and gastrointestinal tract. Blood biomarkers did not appear to be helpful in detecting driveline infections.

Acquired Von Willebrand syndrome is an early-onset problem in ventricular assist device patients

OBJECTIVE

Acquired Von Willebrand syndrome (AVWS) can contribute to bleeding complications in patients with ventricular assist devices (VADs). AVWS results from shear stress, which causes unfolding of the high-molecular-weight (HMW) multimers of Von Willebrand factor (VWF) with subsequent cleavage. Loss of the HMW multimers of VWF is the leading finding in AVWS. In consequence, binding of VWF to collagen and to platelets is impaired. The onset of AVWS after VAD implantation is not yet determined. We examined VAD patients for presence of an AVWS in the early, intermediate, and late phase after VAD implantation.

METHODS

Patients with a biventricular Thoratec-PVAD(®) (BVAD, n = 6) or a left-ventricular HeartMateII(®) (HMII, n = 11) were analyzed prior to VAD implantation and after 1, 3, 14, 30, and 60 days. Diagnosis of AVWS based on VWF:ristocetin cofactor activity/VWF:VWF antigen (VWF:RCo/VWF:Ag), collagen-binding capacity:VWF antigen (VWF:CB/VWF:Ag), and multimeric analysis. In addition, we analyzed the number of bleeding episodes, which required surgical intervention.

RESULTS

No patient had an AVWS prior to VAD implantation. An AVWS was identified already in the very early postoperative period, that is, in almost all patients on the first day and in all patients on the third day. The AVWS was also detected in the majority of patients in the further course. Nine of all 17 patients suffered bleeding complications and required a total of 25 interventions due to hemorrhages. Forty percent of re-interventions were carried out within the first 10 days after implantation; five of these were necessary within the first 24h.

CONCLUSION

The AVWS is present already in the early postoperative phase after VAD implantation. Therefore, reduced shear stress has to be an important feature of newly developed assist devices in the future.

The impact of volume reduction on early and long-term outcomes in surgical ventricular restoration for severe heart failure

BACKGROUND

Recent published results suggest no additive benefit to surgical ventricular restoration (SVR) when combined with coronary artery bypass grafting. However, there may still be a subgroup of patients with severe heart failure who can benefit from this procedure. We reviewed our institutional experience with SVR to determine early and late outcomes based on volume reduction.

METHODS

We retrospectively reviewed our SVR patients (January 2002 to April 2008) with follow-up to March 2009. Baseline comorbidities, operative data, and postoperative outcomes were assessed by chart review, phone calls, and mailings. Survival was modeled using the Kaplan-Meier method. Cardiac magnetic resonance imaging, myocardial perfusion scans, and echocardiography assessed cardiac function, candidacy for SVR, and volume reduction.

RESULTS

We reviewed 87 consecutive SVR patients (69 men). Mean age at operation was 61.1 years. Preoperatively, all patients had congestive heart failure, with 80 (92%) at New York Heart Association III/IV. All patients underwent preoperative viability studies. Three-vessel occlusion exceeding 50% was present in 69 (79%). After SVR, ejection fraction improved from 0.236 to 0.332 (p<0.001). Preoperative and postoperative magnetic resonance imaging in 26 patients (30.0%) showed a 30.8% reduction in left ventricular end systolic volume index. At follow-up, 51 of 66 (77%) improved to New York Heart Association I/II. One intraoperative death occurred. Preoperative left ventricular end systolic volume index of 80 to 120 was associated with improved survival (73% at 3 years).

CONCLUSIONS

SVR is a surgical option for appropriately selected patients with severe congestive heart failure. In these high-risk patients, SVR successfully increased ejection fraction and decreased symptoms. A left ventricular end systolic volume index of 80 to 120 may be the ideal range for SVR procedures.

Transapical miniaturized ventricular assist device: design and initial testing

BACKGROUND

Left ventricular assist devices are increasingly used to treat patients with advanced and otherwise refractory heart failure as bridge to transplant or destination therapy. We evaluated a new miniaturized left ventricular assist device that requires minimal surgery for implantation, potentially allowing implantation in earlier stage heart failure.

METHODS

HeartWare (Miami Lakes, Fla) developed transapical miniaturized ventricular assist device. Acute (n = 4), 1-week (n = 2), and 30-day (n = 4) bovine model experiments evaluated hemodynamic efficacy and biocompatibility of the device, which was implanted through small left thoracotomy with single insertion at apex of left ventricle without cardiopulmonary bypass. The device outflow cannula was positioned across the aortic valve. The international normalized ratio was maintained between 2.0 and 2.5 with warfarin. Hemodynamic, echocardiographic, fluoroscopic, hematologic, and blood chemistry measurements were evaluated.

RESULTS

The device was successfully implanted through the left ventricular apex in all 10 animals. The device was operated at 15,000 ± 1000 rpm (power consumption, 3.5-6.0 W). The device maintained normal end-organ perfusion with no significant hemolysis (0-30 mg/dL). There were no pump failures or device-related complications. At autopsy, no abnormalities were seen in endocardium, aortic valve leaflets, or aortic root. There was no evidence of thromboembolism or abnormalities in any peripheral end organs.

CONCLUSIONS

We successfully demonstrated feasibility of a novel intraventricular assist device that can be completely implanted through left ventricular apex. This transapical surgical approach eliminates needs for sternotomy, device pocket, cardiopulmonary bypass, ventricular coring, and construction of an outflow graft anastomosis.

Interprovincial spoke-to-hub transport using the Impella Recover LP 5.0 left ventricular assist device as a bridge to long-term circulatory support

Current hospital administrative practices categorize health care centres in a network of&nbsp; 'spokes' (primary care centres) and 'hubs' (tertiary care centres). For the treatment of cardiogenic shock, long-term left ventricular assist devices (LVADs) and transplant therapies are only used at a few hub centres nationwide and are, thus, only available to patients living in close proximity to these centres. The relatively lower technical requirements of the Impella Recover LP 5.0 LVAD (ABIOMED Inc, USA) translate into greater use by spoke centres for the short-term treatment of cardiogenic shock, and facilitate appropriate stabilization and subsequent transportation to a suitable hub centre. Based on a review of the literature, the present report describes the first case demonstrating successful use of the Impella Recover LP 5.0 LVAD, implanted under local anesthetic, for the purposes of interprovincial spoke-to-hub transport in a bridge-to-bridge-to-transplant procedure. By providing an economical and technically straightforward alternative to traditional extracorporeal membrane oxygenation, the present case demonstrates that less invasive LVADs are valuable to the spoke-and-hub model for delivery of specialized cardiac care.

Acquired von Willebrand syndrome in continuous-flow ventricular assist device recipients

BACKGROUND

Bleeding is a major cause of morbidity in recipients of continuous-flow left ventricular assist devices (CF-LVAD). A better understanding of the impact of CF-LVAD support on the hemostatic profile is necessary to establish better strategies for anticoagulation therapy and risk assessment for bleeding complications. A prospective multicenter study was conducted to characterize von Willebrand factor (vWF) profiles in patients undergoing CF-LVAD implantation.

METHODS

Blood samples were collected before and after CF-LVAD implantation from 37 patients between July 2008 and April 2009 at Duke University and the University of Minnesota. Blood samples were analyzed for vWF, platelet and collagen-binding ability. The presence of high-molecular-weight (HMW) vWF multimers were detected through gel electrophoresis, and deficiency was graded on a scale of 0 (normal) to 3 (severe loss).

RESULTS

All 37 patients exhibited significant loss of HMW vWF multimers within 30 days of CF-LVAD implantation. Ten of the 37 patients experienced bleeding complications after CF-LVAD placement.

CONCLUSIONS

All CF-LVAD recipients had acquired von Willebrand syndrome after LVAD placement, demonstrated by reduced or absent HMW vWF multimer levels. However, not all recipients had bleeding complications. These findings suggest that loss of HMW vWF multimers alone cannot predict bleeding risk. Further refinement of laboratory techniques and a larger follow-up is required to identify risk factors for bleeding in CF-LVAD recipients.

Effects on pre- and posttransplant pulmonary hemodynamics in patients with continuous-flow left ventricular assist devices

OBJECTIVE

Pulsatile left ventricular assist devices have been shown to effectively reduce pulmonary hypertension in patients with end-stage heart failure. However, it remains to be seen whether newer continuous-flow left ventricular assist devices have a similar effect on pulmonary hypertension. The objective of this study was to determine whether the HeartMate II (Thoratec Corp, Pleasanton, Calif), a continuous-flow left ventricular assist device, is effective in improving pulmonary hemodynamics in the period after left ventricular assist device support and posttransplant.

METHODS

Fifty patients with end-stage heart failure underwent HeartMate II left ventricular assist device placement as a bridge to transplant. We evaluated their pulmonary hemodynamics with right-sided heart catheterization at baseline, after left ventricular assist device placement, and after heart transplant.

RESULTS

The mean age of patients was 53.7 +/- 13.5 years. Ischemic etiology was present in 60% of the patients. After left ventricular assist device placement (mean duration, 135 +/- 60 days), mean systolic and diastolic pulmonary artery pressures decreased significantly from a baseline of 55.2 +/- 13.4 mm Hg and 27.3 +/- 6.8 mm Hg, respectively, to 35.9 +/- 10.8 mm Hg and 15.8 +/- 6.5 mm Hg, respectively (P < .001). Similarly, mean pulmonary vascular resistance decreased significantly from a baseline of 3.6 +/- 1.9 Woods units to 2.1 +/- 0.8 Woods units (P < .001). Posttransplant pulmonary hemodynamics also remained within normal limits, even in patients with previously severe pulmonary hypertension.

CONCLUSION

Continuous-flow left ventricular assist devices effectively improve pulmonary hemodynamics associated with end-stage heart failure. Moreover, pulmonary hemodynamics remain within normal limits in the posttransplant period, even in patients with severe pulmonary hypertension. Therefore, adequate left ventricular decompression achieved with newer left ventricular assist devices can reverse significant pulmonary hypertension in patients with end-stage heart failure, making them eligible for cardiac transplantation.

Aortic valve pathophysiology during left ventricular assist device support

The increased applicability and excellent results with left ventricular assist devices (LVADs) have revolutionized the available treatment options for patients with advanced heart failure. Pre-existing valve abnormalities are common in this population, and subsequent development of valve abnormalities after LVAD placement is also often noted. Although native mitral and tricuspid valve disease is more common in heart failure patients before LVAD placement, aortic valves are much more likely to generate abnormal pathophysiology in the LVAD patient during as well as after LVAD placement. The aim of this comprehensive review is to review aortic valve function in LVAD patients and highlight the consideration of pre-existing valve disease on patient treatment at the time of LVAD implant. The basis for structural changes leading to valve pathophysiology during and after LVAD placement will be described, providing a basis for improved clinical understanding and new strategies to prevent these conditions.

Prevalence of de novo aortic insufficiency during long-term support with left ventricular assist devices

BACKGROUND

Left ventricular assist devices (LVADs) are increasingly used as long-term therapy for end-stage heart failure patients. We compared the prevalence of aortic insufficiency (AI) after HeartMate II (HMII) vs HeartMate XVE (HMI) support and assessed the role of aortic root diameter and aortic valve opening in the development of AI.

METHOD

Pre-operative and post-operative echocardiograms of 93 HMI and 73 HMII patients who received implants at our center between January 2004 and September 2009 were retrospectively reviewed. After excluding patients with prior or concurrent surgical manipulation of the aortic valve, with baseline AI, or without baseline echoes, 67 HMI and 63 HMII patients were studied. AI was deemed significant if mild to moderate or greater. Pathology reports were reviewed for 77 patients who underwent heart transplant.

RESULTS

AI developed in 4 of 67 HMI (6.0%) and in 9 of 63 HMII patients (14.3%). The median times to AI development were 48 days for HMI patients and 90 days for HMII patients. For patients who remained on device support at 6 and 12 months, freedom from AI was 94.5% and 88.9% in HMI patients and 83.6% and 75.2% in HMII patients (log rank p = 0.194). Aortic root diameters, as determined by echocardiography for the patients with AI, trended to be larger at baseline (3.43 ± 0.43 vs 3.15 ± 0.40; p = 0.067) and follow-up (3.58 ± 0.54 vs 3.29 ± 0.50; p = 0.130) compared with those who did not have AI. Aortic root circumferences were assessed directly by a pathologist in those patients who underwent transplant and were significantly larger in HMII patients who had developed AI compared with those patients who did not (8.44 ± 0.89 vs 7.36 ± 1.02 cm; p = 0.034). Lastly, AI was more common in patients whose aortic valve did not open (11 of 26 vs 1 of 14; p = 0.03).

CONCLUSION

Aortic insufficiency occurs frequently in patients who receive continuous-flow support with a HMII LVAD, and may be associated with aortic root diameter enlargement and aortic valve opening. These findings warrant a more thorough preoperative patient evaluation and additional studies to investigate the factors, that may be associated with AI development.

Early adverse events as predictors of 1-year mortality during mechanical circulatory support

BACKGROUND

Ventricular assist devices (VADs) provide effective treatment for end-stage heart failure; however, most patients experience > or =1 major adverse events (AEs) while on VAD support. Although early, non-fatal AEs may increase the risk of later death during VAD support, this relationship has not been established. Therefore, we sought to determine the impact on 1-year mortality of AEs occurring during the first 60 days of VAD support.

METHODS

A retrospective analysis was performed using prospectively collected data from a single-site database for patients aged > or =18 years receiving left ventricular or biventricular support during 1996 to 2008 and who survived >60 days on VAD support. Fourteen major classes of AEs occurring during this 60-day period were examined. One-year survival rates of patients with and without each major AE were compared.

RESULTS

The study included 163 patients (80% men; mean age, 49.5 years), of whom 87% were European American, 72% had left ventricular support, and 83% were bridge to transplant. The occurrence of renal failure, respiratory failure, bleeding events, and reoperations during the first 60 days after implantation significantly increased the risk of 1-year mortality. After controlling for gender, age, VAD type, and intention to treat, renal failure was the only major AE significantly associated with later mortality (hazard ratio, 2.96; p = .023).

CONCLUSIONS

Specific AEs, including renal failure, respiratory and bleeding events, and reoperations, significantly decrease longer-term survival. Renal failure conferred a 3-fold increased risk of 1-year mortality. Peri-operative management should focus on strategies to mitigate risk for renal failure in order to maximize later outcomes.

Update on ventricular assist devices

PURPOSE OF REVIEW

Over the past two decades, medicine has seen a robust increase in the use of ventricular assist devices. The purpose of this review is to update the information concerning these devices, their advantages and disadvantages as well as their complications. This is essential, as the demand for these devices is increasing due to the increasing number of patients with end-stage heart failure and limited number of donor hearts available for transplantation.

RECENT FINDINGS

First-generation devices consisted of large, cumbersome consoles requiring patient immobilization and often times hospitalization in an ICU setting. Second-generation models focused on patient mobility and discharge from hospital with an improvement in infection rates as well as 1 and 2-year survival rates. Designs for newer devices are focusing on full implantation without percutaneous lines, axial flow mechanisms and patient comfort. Additionally, total artificial hearts are being designed for the treatment of biventricular failure. The indications for ventricular assist devices are also being expanded to include destination therapy and alternatives to cardiac transplantation, as the supply of organs continues to be limiting.

SUMMARY

This paper reviews the characteristics, outcomes and design of ventricular assist devices.

Increased incidence of gastrointestinal bleeding following implantation of the HeartMate II LVAD

BACKGROUND

The HeartMate II (HMII) Left Ventricular Assist System (Thoratec Corporation, Pleasanton, CA, USA), an axial continuous-flow left ventricular assist device (LVAD), has been approved for use in bridge-to-transplant patients and is under investigation for destination therapy. To avoid device-related thromboembolic complications, antiplatelet, and anticoagulation therapy are routinely administered. A worrisome frequency of gastrointestinal (GI) bleeding events has been observed.

METHODS

A retrospective review of all 33 patients undergoing long-term LVAD implantation between June 1, 2006 and July 31, 2008 at our institution for any indication was conducted. Anticoagulation consisted of heparin (intravenous or subcutaneous) followed by transition to Coumadin therapy to a target INR of two to three. Antiplatelet therapy consisted of low-dose aspirin and dipyridamole.

RESULTS

Twenty patients received the HMII and 13 patients received other devices. Eight (40%) HMII recipients suffered at least one episode of GI bleeding while no GI bleeding occurred in recipients of other devices (p = 0.012). Of 17 total bleeding episodes, no definitive source could be identified in 11 instances (65%).

CONCLUSIONS

Although definitive source identification remains elusive, we believe that the majority of bleeding arises in the small bowel, possibly due to angiodysplasias, similar to the pathophysiology encountered in patients with aortic stenosis and GI bleeding. As we move toward wider use of the HMII and other axial continuous-flow devices in both bridge-to-transplant patients and for destination therapy, more studies will be necessary to understand the mechanisms of this obscure GI bleeding and develop treatment strategies to minimize its development.

Mechanical circulatory support in the ICCU

The mortality of acute heart failure (AHF) remains high despite advances in treatment. Mechanical circulatory support (MCS) can be applied in AHF, refractory to conventional measures, to improve outcomes. This article aims to describe the current and the prospective role of MCS in the treatment of AHF. The support strategies and the indications of MCS are continuously evolving, including situations considered as contraindications in the past. Appropriate patient selection, advanced device technology and improved patient management have contributed to the substantially improved results. Evolution in device technology results in evolution of the clinical applications of MCS. Earlier application of MCS, with novel, flexible and individualized support strategies is now feasible. Bridging to recovery is the most intriguing support strategy and bridging to future treatments is feasible with long-term support. The progressively expanding role of MCS in the treatment of heart failure is not reflected in the existing guidelines. Being reserved for refractory heart failure, MCS has been applied to the sickest patients who were less amenable to randomization. This explains the lack of robust evidence, but also highlights the value of the progressively improving results. The anticipated wider application of MCS should be better defined, systematically recorded, and guided.

Clinical management of continuous-flow left ventricular assist devices in advanced heart failure

Continuous-flow left ventricular assist devices (LVAD) have emerged as the standard of care for advanced heart failure patients requiring long-term mechanical circulatory support. Evidence-based clinical management of LVAD-supported patients is becoming increasingly important for optimizing outcomes. In this state-of-art review, we propose key elements in managing patients supported with the new continuous-flow LVADs. Although most of the presented information is largely based on investigator experience during the 1,300-patient HeartMate II clinical trial, many of the discussed principles can be applied to other emerging devices as well. Patient selection, pre-operative preparation, and the timing of LVAD implant are some of the most important elements critical to successful circulatory support and are principles universal to all devices. In addition, proper nutrition management and avoidance of infectious complications can significantly affect morbidity and mortality during LVAD support. Optimizing intraoperative and peri-operative care, and the monitoring and treatment of other organ system dysfunction as it relates to LVAD support, are discussed. A multidisciplinary heart failure team must be organized and charged with providing comprehensive care from initial referral until support is terminated. Preparing for hospital discharge requires detailed education for the patient and family or friends, with provisions for emergencies and routine care. Implantation techniques, troubleshooting device problems, and algorithms for outpatient management, including the diagnosis and treatment of related problems associated with the HeartMate II, are discussed as an example of a specific continuous-flow LVAD. Ongoing trials with other continuous-flow devices may produce additional information in the future for improving clinical management of patients with these devices.

The future is here: ventricular assist devices for the failing heart

Mechanical circulatory support is an important adjunct to the management of patients with advanced heart failure. Technological advances in this area have improved overall survival and decreased the incidence of complications. In addition, they have expanded the population suitable for this therapy. The challenge for clinicians is to translate the clinical evidence into the selection of the most appropriate device that will benefit an individual patient. This paper will review ventricular assist devices currently available and their clinical indications.

Noninvasive predictor of HeartMate XVE pump failure by neural network and waveform analysis

Patients increasingly require longer durations of left ventricular assist device (LVAD) therapy. Despite a recent trend toward continuous flow VADs, the HeartMate XVE is still commonly used, but its longevity remains a significant limitation. Existing surveillance methods of pump failure often give inconclusive results. XVE electrical current waveforms were collected regularly (2001-2008) and sorted into quartiles according to number of days until pump failure (Q1, 0-34; Q2, 34-160; Q3, 160-300; and Q4, 300-390 days). Thoratec waveform files were converted into text files. The 10-second electrical current, voltage waveform was identified and isolated for analysis. Waveforms were analyzed by principal component analysis (PCA) and with a fast Fourier transform. Quartiles were compared with analysis of variance (ANOVA). Waveforms (n = 454) were collected for 21 patients with failed pumps. An artificial neural network was used to predict pump failure within 30 days from the waveform characteristics identified though signal processing.

Quality of life and functional status in patients surviving 12 months after left ventricular assist device implantation

BACKGROUND

As left ventricular assist device (LVAD) support duration increases, quality of life (QoL) becomes a concern. We reviewed the QoL in patients on LVAD support for >or=1 year.

METHODS

We retrospectively reviewed our prospective database for patients supported >or=1 year by HeartMate pulsatile- (HM1) or continuous-flow (HM2) LVADs from 2000 to 2009. Transplant or death before 1 year merited exclusion. Metabolic equivalents of tasks (METs), the Minnesota Living with Heart Failure Questionnaire (MLHFQ), the 6-minute walk distance (6MWD), and New York Heart Association (NYHA) class were reviewed. Complications and re-admissions were assessed.

RESULTS

Thirty patients were supported for >or=1 year (7 HM1s, 23 HM2s). Mean support duration was 594 +/- 173 days. Mean QoL metrics/functional status indicators at 12 months were: 6MWD, 393 +/- 290 m; MET tolerance, 3.3 +/- 1; MLHFQ, 35 +/- 31; and NYHA, 1.4 +/- 0.6. Mean re-admissions/year was 2.9 +/- 2, with a duration of 13.8 +/- 21 days. Three patients were never re-admitted. Mean out-of-hospital time was 471 +/- 172 days (87.3% of days). Infectious complications led to 43% of re-admissions and occurred in the: drive-line (47%) at 442 +/- 236 days; blood (37%) at 472 +/- 257 days; and LVAD pocket (20%) at 550 +/- 202 days. Twenty-three patients (77%) required additional operations (1.7 +/- 1.8/year). The most common indication was drive-line infection, but ranged from ischemic bowel to defibrillator exchange. Eight required LVAD exchanges for mechanical (n = 4), electrical (n = 3), and thrombotic (n = 1) issues.

CONCLUSIONS

Although LVAD support is not without complications, patients spend the majority of time outside the hospital enjoying a good quality of life.

Low Operative Mortality With Implantation of a Continuous-Flow Left Ventricular Assist Device and Impact of Concurrent Cardiac Procedures

Background— The objective of this study was to determine the impact of concurrent cardiac procedures (CCP) on patient outcomes after HeartMate II (HMII) left ventricular assist device implantation.

Methods and Results— Two hundred eighty-one patients underwent implantation of a HMII as a bridge to transplantation from March 2005 to March 2007. One hundred seventy patients had an HMII implanted only, and 81 patients underwent concurrent cardiac procedures in conjunction with HMII implantation (HMII+CCP). Of these, 47 patients had concurrent valvular procedures, 15 patients had simultaneous closure of patent foramen ovale, and 19 patients had other various cardiac procedures. Patients requiring right ventricular assist device support or noncardiac procedures were excluded. Preoperative characteristics were similar for patients with and without concurrent cardiac procedures. Overall 30-day mortality was 5.8% for the HMII group and 11.3% for the HMII+CCP group. Subgroup analysis demonstrated that simultaneous patent foramen ovale closure was not associated with an increased 30-day mortality rate, but concurrent valvular procedures increased the risk to 8.5%. Patients who underwent an aortic valve procedure had a 30-day mortality rate of 25%, higher than for isolated concurrent mitral (0%) or tricuspid repair (3.3%). Survival at 180 days was 87% for HMII alone and 80% for HMII+CCP. The hazard ratio for concurrent cardiac procedures adjusted for baseline parameters was 1.82 (95% CI, 1.07 to 3.10, P =0.026).

Conclusions— There is a low 5.8% operative mortality rate for patients requiring uncomplicated HMII implantation, with no apparent increased risk for concurrent patent foramen ovale closure or mitral or tricuspid repair. However, concurrent aortic valve and other cardiac procedures are associated with significantly decreased perioperative and long-term survival.

Recent progress in heart failure treatment and heart transplantation

There has been significant progress in heart failure treatment; its stages are defined as a management platform for cardiovascular specialists. Surgical ventricular restoration adds no outcome advantage in ischemic heart failure over coronary artery bypass surgery alone. Novel medical therapies may include cytokine blockade and the vasodilator, relaxin. Although diastolic failure is prevalent, its clinical significance is unclear. Cardiac resynchronization reduces mortality and hospitalization. Perioperative enoximone facilitates beta-blockade for prophylaxis against myocardial ischemia. Heart failure still determines outcome in pulmonary embolism and cardiac surgery. The practice of ventricular assist devices continues to progress. A profile system based on urgency of mechanical support will guide future outcome assessment. Clinical scoring systems will guide the management of right heart failure. Device flow determines the risk of cerebral hyperperfusion and neurologic dysfunction. Regardless of device type, renal dysfunction remains an important outcome determinant. Postoperative heparinization is increasingly challenged because of the risks of bleeding and heparin-induced thrombocytopenia. The practice of heart transplantation continues to mature. The bicaval rather than the biatrial technique improves short-term outcome. Oral sildenafil is effective for pulmonary hypertension and right ventricular support. Although immunosuppression with tacrolimus is beneficial, sirolimus is less nephrotoxic and preserves coronary vasomotor function. The induction of immunosuppression may be modified as it has a weak evidence base. Psychosocial factors also continue to influence clinical outcome significantly. The future of heart failure treatment is bright with signs of active growth and progress in this vibrant subspecialty.

Sociology meets genetics: sociogenetic implications for future management of hypertension and heart failure

Hypertension and heart failure contribute significantly to morbidity and mortality in the United States. Suboptimal control of these disease processes is multifactorial and involves poorly understood mechanisms affected by the environment (socioeconomic factors) and genetics (cell biology). Dietary sodium is an illustrative case. Although physicians intuitively accept that sodium affects renal and cardiovascular physiology, the complex overlay of genetics, environment, and culture is not practically addressed to make a meaningful difference in patient care. Optimal control of hypertension and heart failure will require a personalized care plan for each patient that includes lifestyle changes and carefully selected pharmacotherapy and also accounts for sociogenetic factors that affect each patient's life and thus his or her disease process. Physicians' cultural biases and perceptions also must be factored into this complex patient care equation.

Renal function and outcome after continuous flow left ventricular assist device implantation

BACKGROUND

Renal dysfunction as a risk factor with the use of left ventricular assist devices (LVAD) is controversial. We determined the effect of renal function on outcomes after continuous flow LVAD implantation.

METHODS

Eighty-six patients with advanced heart failure undergoing continuous flow LVAD implantation as bridge to transplantation from November 1998 to July 2007 were retrospectively analyzed. Renal function was assessed using the Modification of Diet in Renal Disease study-derived glomerular filtration rates (GFR [mL x min(-1) x 1.73 m(-2)]). Patients were categorized into two groups based on pre-LVAD GFR: those with normal renal function (GFR > 60, n = 46), and those with renal dysfunction (GFR < 60, n = 40).

RESULTS

Post-LVAD survival at 1, 3, and 6 months for GFR greater than 60 was 91.3%, 79.9%, 72.6%, respectively, and for GFR less than 60, it was 92.5%, 66.5%, 47.9%, respectively (p = 0.038). Bridge-to-transplant rate was lower for GFR less than 60 than for GFR greater than 60 (40.0% versus 63.0%, p = 0.033). For GFR less than 60, GFR improved on LVAD support: implant to month 6, 41.7 +/- 11.5 to 62.7 +/- 25.0 (p = 0.021). Post-LVAD survival was improved in GFR less than 60 patients who after LVAD implantation recovered renal function to GFR greater than 60 (p < 0.001). Patients with post-LVAD renal failure had significantly lower post-LVAD survival regardless of pre-LVAD renal function (p < 0.001).

CONCLUSIONS

Patients with renal dysfunction have poorer outcomes after continuous flow LVAD implantation. However, renal function improves after LVAD implantation and is associated with improved survival. Our data underscore the importance of end-organ function in patient selection for LVAD therapy.

Physiologic and pathologic changes in patients with continuous-flow ventricular assist devices

The clinical use of the newer continuous-flow pumps for mechanical circulatory support have resulted in superior outcomes including significantly reduced complication rates with improved durability over first generation pulsatile design pumps. However, as with all new technology, the newer LVADs have introduced a different set of management issues, as well as a unique risk profile into the mechanical circulatory support arena that were previously absent or unimportant with pulsatile LVADs. These include the effects of continuous flow on the systemic circulation and end-organ function, risk of thromboembolism, and pump thrombosis related to contact bearings in the blood path, the possible increased incidence of gastrointestinal bleeding, and ventricular arrhythmias, as well as alterations in the unloading characteristics of continuous-flow devices. This manuscript overviews the physiologic and pathologic effects that are associated with continuous-flow pumps and their unique management issues and complications.