Experience with the HeartMate II Left Ventricular Assist Device in Patients Older than 60 Years.

BACKGROUND: Advanced age is a relative contraindication for heart transplantation, but no age cutoff has been defined for patients receiving mechanical circulatory support. METHODS: Between November 1, 2003 and November 1, 2012, we implanted the HeartMate II (HMII) left ventricular assist device (LVAD) in 319 patients. One hundred seven patients (89 men, 18 women) were over 60 years old (mean, 66 ± 4 years, range, 61-78 years) and received the HMII as a bridge to transplantation (n = 45) or as destination therapy (n = 62). We evaluated their experience by performing a retrospective analysis. RESULTS: Seventy-two patients had ischemic cardiomyopathy, and 34 had idiopathic cardiomyopathy. Three patients (2.8%) already had a HeartMate XVE LVAD, 54 (50.5%) were receiving intra-aortic balloon pump support, 52 (48.6%) had undergone a previous cardiac procedure, and 9 (8.4%) had received renal replacement therapy (RRT) (continuous venovenous hemofiltration, hemodialysis, or both) before HMII implantation. The median duration of HMII support was 313 days (range, 1-3339 days). After device implantation, 36 patients (33.6%) had gastrointestinal bleeding, 24 (23%) required RRT, 18 (17.5%) had ventricular arrhythmias, and 24 (22.4%) had LVAD-related infections, and 9 (8.4%) had right ventricular failure requiring mechanical support, and 28 (26.2%) had neurologic complications. The actual survival rate was 69% at 6 months, 63% at 1 year, and 54% at 2 years. Eighty-one patients died, 9 are still receiving HMII support, and 17 are alive after heart transplantation. CONCLUSIONS: Older patients can benefit from LVAD therapy, and advanced age should not preclude LVAD implantation.

Evaluation of Resting Cardiac Power Output as a Prognostic Factor in Patients with Advanced Heart Failure.

If the heart is represented by a hydraulic pump, cardiac power represents the hydraulic function of the heart. Cardiac pump function is frequently determined through left ventricular ejection fraction using imaging. This study aims to validate resting cardiac power output (CPO) as a predictive biomarker in patients with advanced heart failure (HF). One hundred and seventy-two patients with HF severe enough to warrant cardiac transplantation were retrospectively reviewed at a single tertiary care institution between September 2010 and July 2013. Patients were initially evaluated with simultaneous right-sided and left-sided cardiac catheter-based hemodynamic measurements, followed by longitudinal follow-up (median of 52 months) for adverse events (cardiac mortality, cardiac transplantation, or ventricular assist device placement). Median resting CPO was 0.54 W (long rank chi-square = 33.6; p < 0.0001). Decreased resting CPO (<0.54 W) predicted increased risk for adverse outcomes. Fifty cardiac deaths, 10 cardiac transplants, and 12 ventricular assist device placements were documented. The prognostic relevance of resting CPO remained significant after adjustment for age, gender, left ventricular ejection fraction, mean arterial pressure, pulmonary vascular resistance, right atrial pressure, and estimated glomerular filtration rate (HR, 3.53; 95% confidence interval, 1.66 to 6.77; p = 0.0007). In conclusion, lower resting CPO supplies independent prediction of adverse outcomes. Thus, it could be effectively used for risk stratification in patients with advanced HF.

Ventricular reconditioning and pump explantation in patients supported by continuous-flow left ventricular assist devices.

BACKGROUND: The potential for myocardial reconditioning and device explantation after long-term continuous-flow left ventricular assist device (LVAD) support presents an opportunity to delay or avoid transplantation in select patients. METHODS: Thirty of 657 patients with end-stage heart failure supported with continuous-flow LVADs were assessed for device explantation. Each patient underwent an individualized process of weaning focused on principles of ventricular unloading, gradual reconditioning, and transition to medical therapy. RESULTS: After varying reconditioning periods, 27 patients (16 men, 11 women; age, 39 ± 12 years) underwent LVAD explant, and 3 patients (2 men, 1 woman; age, 22 ± 6 years) were evaluated for explantation but could not be weaned. The duration of LVAD support was 533 ± 424 days (range, 42-1,937 days) for the explant cohort and 1,097 ± 424 days (range, 643-1,483) for the non-explant cohort. The LV end-diastolic dimension, LV ejection fraction, systolic pulmonary artery pressure, cardiac output, and cardiac index in the explant cohort were significantly improved at explantation (all, p < 0.05). Two late deaths occurred after LVAD explantation despite satisfactory native cardiac function, and 1 patient required resumption of LVAD support 2.7 years after device removal. The remaining explant patients remain in New York Heart Association classes I to II with medical management alone (mean survival post-explant, 1,172 ± 948 days). The 3 candidates who could not be weaned ultimately underwent transplantation. CONCLUSIONS: The potential for recovery of native LV function after long-term continuous-flow LVAD support should encourage a more aggressive approach to ventricular reconditioning with the goal of device explantation and a return to medical management, particularly in young patients with dilated cardiomyopathy.

HeartMate II left ventricular assist device implantation in patients with advanced hepatic dysfunction.

BACKGROUND: We sought to determine the outcomes for patients with advanced hepatic dysfunction undergoing HeartMate II left ventricular assist device (LVAD) implantation. METHODS: Between November 1, 2003 and December 1, 2012, we implanted the HeartMate II continuous-flow LVAD in 338 patients, either for bridging to heart transplantation or for destination therapy. Twenty-three of these patients (19 men and 4 women; mean age, 47 ± 16 years) had advanced hepatic dysfunction, as characterized by alanine aminotransferase (ALT) or aspartate transaminase (AST) levels five times normal; serum total bilirubin levels three times normal; and/or necessity for a liver biopsy before or during device implantation. Of this group, 17 patients received the LVAD as a bridge to transplantation, and six patients received it for destination therapy. RESULTS: Nine of the 23 patients required either a transjugular or a core liver biopsy during LVAD implantation. Three patients died within the first postoperative month; the 20 surviving patients had significant improvements in their hepatic parameters. The ALT decreased from 238 ± 296 to 27 ± 13 U/L (p = 0.022), AST decreased from 209 ± 199 to 29 ± 8 U/L (p = 0.009), and total bilirubin level decreased from 6.9 ± 6.0 to 0.6 ± 0.1 mg/dL (p = 0.044). The serum albumin level increased from 3.2 ± 0.6 to 4.3 ± 0.3 g/dL (p = 0.003), and creatinine clearance increased from 77.6 ± 35.2 to 110.2 ± 35.7 mL/min/1.73 m2 (p = 0.101). CONCLUSION: Continuous-flow LVAD support may significantly improve hepatic function, allowing patients with poor preimplant liver function to become better candidates for heart transplantation.

Granulomatous myocarditis in severe heart failure patients undergoing implantation of a left ventricular assist device.

BACKGROUND: Granulomatous myocarditis may develop into cardiomyopathy and severe congestive heart failure that requires implantation of a left ventricular assist device (LVAD). METHODS: Left ventricular (LV) core samples were collected from 177 patients with severe heart failure at the time of LVAD implantation, and samples were histologically examined and graded for severity of hypertrophy and fibrosis. Granulomatous myocarditis incidentally seen in a subset of samples was characterized by staining and culturing for mycobacteria and fungi. Various clinical parameters in these patients were analyzed. RESULTS: Of the 177 LV core samples examined, 6 (3.4%) showed nonnecrotizing granulomatous inflammation in the myocardial wall. Stains and cultures for mycobacteria and fungi were negative. All six patients [three women, three men; five African American, one Asian; mean age, 52±9 years (range, 41-61 years)] had arrhythmias and required an automatic implantable cardioverter defibrillator. Before LVAD implantation, the patients' mean cardiac index was 1.8±0.4 l/min/m(2); cardiac output, 2.9±0.6 l/min; and ejection fraction, 20±2%. One year after LVAD implantation, one patient had undergone heart transplantation. At 2 years, a second patient was transplanted, and one died. At 3 years, a third patient was transplanted and died postoperatively; two patients remained on support. No clinical evidence indicated involvement of other organs or recurrence in the transplanted patients. CONCLUSION: The incidental diagnosis of granulomatous myocarditis in our patients indicates that histological study of LV core samples in patients who undergo LVAD implantation may contribute to the diagnosis and be a consideration in the management of the underlying cause of heart failure.

Morphologic changes in the aortic wall media after support with a continuous-flow left ventricular assist device.

BACKGROUND: Continuous-flow left ventricular assist devices (LVADs) provide durable, reliable, energy-efficient long-term support. However, the biologic effects of continuous flow are not completely known. Therefore, we examined aortic wall morphology in patients with heart failure before and after prolonged circulatory support with a continuous-flow LVAD. METHODS: After applying a partial aortic occlusion vascular clamp in the lower half of the ascending aorta, we removed samples of aortic wall tissue and then attached the outflow graft of the pump. Samples were obtained from 11 patients (9 men and 2 women, mean age 65 ± 7 years) with severe heart failure at the time of LVAD implantation. We obtained matched specimens at explantation after heart transplantation (n = 5) or autopsy (n = 6). These specimens were removed from the distal ascending aorta, remote from the aortic anastomotic site. Tissue sections were stained with hematoxylin and eosin, Movat's pentachrome and Masson's trichrome. Smooth muscle actin immunohistochemistry was performed on all sections. To evaluate the morphology of the aortic wall media, we quantitatively graded tissue sections for medial thickness, medial degenerative changes, smooth muscle cell (SMC) disorientation and depletion, elastic fiber fragmentation and depletion, medial fibrosis and atherosclerotic changes. RESULTS: The mean duration of support was 140 ± 136 days (range 87 to 580 days). The histologic evaluation and comparison of specimens obtained before and after LVAD support showed significantly increased foci of medial degeneration, SMC depletion, elastic fiber fragmentation, medial fibrosis and atherosclerotic changes after LVAD support. Mean medial thickness was not significantly different after LVAD support. We observed similar changes between samples obtained at transplantation and those obtained at autopsy. CONCLUSIONS: After continuous-flow LVAD support, the morphology of the aortic wall media was altered in all of our patients. The clinical relevance of these findings is unknown.

Aortic valve noncoronary cusp thrombosis after implantation of a nonpulsatile, continuous-flow pump.

Different institutions have different strategies for managing both native and prosthetic aortic valves in recipients of left ventricular assist devices (LVADs). Anticoagulation protocols and pump-flow algorithms remain nonstandardized. We describe our institutional experience with thrombotic complications and our evolving approach to this important clinical problem. We report the cases of 4 HeartMate II LVAD recipients in whom, despite an anticoagulative regimen, thrombus formed on the noncoronary cusp of the aortic valve. The management of the closed aortic valve in LVAD-supported patients remains problematic.

Adenocarcinoma of the parotid gland metastatic to the ventricular septum and right ventricular wall.

Adenocarcinoma of the parotid gland metastatic to the right ventricle has rarely been reported in the medical literature. We describe the case of a 51-year-old man who had a right ventricular adenocarcinoma that metastasized from his right parotid gland. He had undergone incomplete resection of the parotid tumor, followed by radiotherapy, 5 years earlier. After resecting the cardiac adenocarcinoma with tumor-free margins, we reconstructed the ventricular septum and right ventricle, then performed coronary artery bypass grafting. At the patient's most recent follow-up examination 6 months later, he continued to do well and had a good quality of life.

Remission of chronic, advanced heart failure after left ventricular unloading with an implantable left ventricular assist device.

We describe the case of a 35-year-old man with severe, dilated idiopathic cardiomyopathy who was placed on the waiting list for cardiac transplantation. While awaiting transplantation, his heart failure decompensated to such a degree that left ventricular assist device support was necessary. He did well on device support until a pump-pocket infection (methicillin-resistant coagulase-negative staphylococci) developed at 10 months. At that time, echocardiograms showed normal heart size and an ejection fraction of 0.45 to 0.49 without pump support. The pump was, therefore, explanted emergently. The patient has remained clinically stable with preserved ventricular function nearly 13 years after the explantation procedure.

Arteriovenous malformation and gastrointestinal bleeding in patients with the HeartMate II left ventricular assist device.

BACKGROUND: In this study we investigated gastrointestinal (GI) bleeding and its relationship to arteriovenous malformations (AVMs) in patients with the continuous-flow HeartMate II (HMII) left ventricular assist device (LVAD). METHODS: The records of 172 patients who received HMII support between November 2003 and June 2010 were reviewed. Patients were considered to have GI bleeding if they had 1 or more of the following symptoms: guaiac-positive stool; hematemesis; melena; active bleeding at the time of endoscopy or colonoscopy; and blood within the stomach at endoscopy or colonoscopy. The symptom(s) had to be accompanied by a decrease of >1 g/dl in the patient's hemoglobin level. The location of the bleeding was identified as upper GI tract, lower GI tract or both according to esophagogastroduodenoscopy, colonoscopy, small-bowel enteroscopy or mesenteric angiography. Post-LVAD implantation anti-coagulation therapy consisted of warfarin, aspirin and dipyridamole. RESULTS: Thirty-two of the 172 patients (19%) had GI bleeding after 63 ± 62 (range 8 to 241) days of HMII support. Ten patients had GI bleeding from an AVM; these included 3 patients who had 2 bleeding episodes and 2 patients who had 5 episodes each. Sixteen patients had upper GI bleeding (10 hemorrhagic gastritis, 4 gastric AVM, 2 Mallory-Weiss syndrome), 15 had lower GI bleeding (6 diverticulosis, 6 jejunal AVM, 1 drive-line erosion of the colon, 1 sigmoid polyp, 1 ischemic colitis) and 1 had upper and lower GI bleeding (1 colocutaneous and gastrocutaneous fistula). All GI bleeding episodes were successfully managed medically. CONCLUSIONS: Arteriovenous malformations can cause GI bleeding in patients with continuous-flow LVADs. In all cases in this series, GI bleeding was successfully managed without the need for surgical intervention.

Thrombotic occlusion of an aortic-root xenograft during left ventricular assistance.

A 45-year-old man underwent repair of a congenital bicuspid aortic valve and complex aortic-root aneurysm with an aortic-root xenograft. A CentriMag® left ventricular assist device was implanted for cardiac support and was subsequently replaced with a HeartMate II® left ventricular assist device. A day later, the patient was returned to the operating room for control of bleeding, and thrombotic occlusion of the prosthetic aortic valve was detected. The patient underwent thrombus removal, oversewing of the prosthetic valve, and bypass of the left anterior descending coronary artery. This case emphasizes the hazard of bypassing a failed left ventricle with a cardiac assist device after aortic valve replacement, even with a bioprosthesis.

Results of HeartMate II left ventricular assist device implantation on renal function in patients requiring post-implant renal replacement therapy.

BACKGROUND: Renal function is often compromised in patients with advanced heart failure. METHODS: We evaluated renal function in heart failure patients supported by the HeartMate II (Thoratec Corporation, Pleasanton, CA) continuous-flow left ventricular assist device (LVAD) who required renal replacement therapy (RRT) by continuous venovenous hemofiltration dialysis (CVVHD) or hemodialysis, or both. Indications for RRT included oliguria (urine < 400 ml/day) unresponsive to diuretic therapy for > 24 hours with a creatinine level > 2.0 mg/dl or 1.5 times that of the pre-implant creatinine level, severe acidemia, and volume overload. RESULTS: Of 107 consecutive patients who underwent HeartMate II implantation at our center and had been supported for > 30 days, 15 (13 men and 2 women) required post-implant RRT. Of the 15 patients, 3 received CVVHD and 12 received CVVHD and hemodialysis. Renal function improved within 2 months of support compared with average values before support (creatinine clearance, 64 ± 39 vs 92 ± 55 ml/min, p = 0.041; glomerular filtration rate, 46.9 ± 20.7 vs 73.2 ± 38.9 ml/min/1.73 m(2); p = 0.032). Renal function improved after HeartMate II implantation in 10 patients, and RRT was removed. Of these 10 patients, 2 underwent heart transplantation 4 months after RRT was removed, 1 underwent heart and kidney transplantation 4 years later, 2 died at home of conditions unrelated to renal function 6 months after RRT was removed, and 5 are awaiting heart transplantation, with good quality of life. CONCLUSIONS: In this study, patients who experienced clinical recovery after the LVAD implant had subsequent recovery of renal function after continuous-flow LVAD support.

Surgical closure of left ventricular outflow tract after left ventricular assist device implantation in patients with aortic valve pathology.

BACKGROUND: In patients with refractory heart failure, aortic valve (AV) insufficiency or the presence of a prosthetic AV has been considered a relative contraindication to left ventricular assist device (LVAD) therapy. Nevertheless, we have successfully implanted LVADs in 5 patients with native AV insufficiency or an AV prosthesis by closing the left ventricular outflow tract (LVOT). METHODS: The method of LVOT closure was tailored to the patients' differing circumstances. Patient 1 had a regurgitant tri-leaflet native AV. Patient 2 had undergone previous aortic root reconstruction with a porcine bioprosthesis. Patient 3 had a congenitally bicuspid AV with significant insufficiency. Patient 4 had a native tri-leaflet valve that developed thrombus and insufficiency after previous LVAD placement. Patient 5 required removal of a recently placed mechanical AV. Accordingly, the LVOT was closed with a bovine pericardial patch in Patients 1, 4 and 5, and the lines of coaptation of the AV leaflets were closed primarily in Patients 2 and 3. RESULTS: Four months post-operatively, 1 patient underwent heart transplantation; on removal of the heart, LVOT patch integrity was confirmed visually. After a follow-up period of 6 months to 2 years, the remaining 4 patients are in New York Heart Association Functional Class I while awaiting cardiac transplantation. Transesophageal echocardiography has confirmed persistent LVOT closure. CONCLUSION: In all 5 cases, LVOT closure circumvented the challenges associated with LVAD therapy in the presence of native AV insufficiency or an AV prosthesis.

Left ventricular pseudoaneurysm arising between two papillary muscles: repair without mitral regurgitation.

Left ventricular pseudoaneurysm is a rare lesion that occurs when a contained free-wall rupture occurs after a transmural myocardial infarction. Such a pseudoaneurysm may be lethal if subsequent rupture or progressive heart failure occurs. We describe a 67-year-old man who, one year after undergoing coronary artery bypass grafting, developed an infero-apical left ventricular pseudoaneurysm between the bases of two papillary muscles without incurring significant mitral regurgitation. This was a highly unusual presentation. We were able to repair the aneurysm and restore normal mitral geometry without causing regurgitation.