Management of multiple left ventricular assist device failures in a patient.

Device failure is a rare but life-threatening complication in patients receiving mechanical circulatory support. Because patients are supported by these devices for longer periods, the incidence of device failure has increased. We report 3 instances of device failure and successful surgical management in a single patient.

Simultaneous insertion of a left ventricular assist system and repair of an ascending aortic dissection.

Operative methods for repairing ascending aortic dissections and for implanting left ventricular assist systems have been thoroughly presented in the medical literature. Only a few reports, however, describe the concomitant performance of these procedures in 1 patient. We report the repair of an acute ascending aortic dissection with simultaneous placement of a long-term left ventricular assist system. One week earlier, the patient had undergone emergent coronary artery bypass grafting and short-term postcardiotomy ventricular assistance when he could not be weaned from cardiopulmonary bypass. By creating a graft-to-graft anastomosis on the bench during cooling of the patient on cardiopulmonary bypass, we were able to shorten to 21 minutes the period of hypothermic circulatory arrest required during ascending aortic dissection repair. The procedures were completed successfully. However, the patient developed pneumonia and sepsis during his extended hospital stay and died of multiorgan failure 5 weeks postoperatively.

Brain natriuretic peptide levels and response to cardiac resynchronization therapy in heart failure patients.

The authors used brain natriuretic peptide (BNP) as a reliable marker to identify nonresponders to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. The study included 70 patients with left ventricular dysfunction (mean ejection fraction, 21+/-4%) and left bundle branch block (QRS duration, 164+/-25 milliseconds) treated with CRT. The authors reviewed data on New York Heart Association functional class, baseline ejection fraction, sodium, creatinine, QRS duration, and BNP levels 3 months before and after CRT therapy. The authors compared results of 42 patients who survived (973+/-192 days) after CRT implantation (responders) to those of 28 patients (nonresponders) who either expired (n=21) or underwent heart transplantation (n=5) or left ventricular assist device implantation (n=2) after an average of 371+/-220 days. Mean BNP levels after 3 months of CRT decreased in responders from 758+/-611 pg/mL to 479+/-451 pg/mL (P=.044), while in nonresponders there was increase in BNP levels from 1191+/-466 pg/mL to 1611+/-1583; P=.046. A rise in BNP levels was associated with poor response (death or need for transplantation or left ventricular assist device and impaired long-term outcome), which makes it a good predictor to identify such patients.

Clinical experience with the TandemHeart percutaneous ventricular assist device.

The TandemHeart percutaneous ventricular assist device can be used to support patients in cardiogenic shock (until cardiac recovery occurs or as a bridge to definitive therapy) or as a temporary application during high-risk coronary interventions. The TandemHeart is a left atrial-to-femoral artery bypass system comprising a transseptal cannula, arterial cannulae, and a centrifugal blood pump. The pump can deliver flow rates up to 4.0 L/min at a maximum speed of 7500 rpm. From May 2003 through May 2005, the TandemHeart was used to support 18 patients (11 in cardiogenic shock and 7 undergoing high-risk percutaneous transluminal coronary angioplasty). The patients in cardiogenic shock were supported for a mean of 88.8 +/- 74.3 hours (range, 4-264 hr) at a mean pump flow rate of 2.87 +/- 0.56 L/min (range, 1.8-3.5 L/min). The mean cardiac index improved from 1.57 +/- 0.31 L/min/m2 before support to 2.60 +/- 0.34 L/min/m2 during support. The mean duration of support for the high-risk percutaneous transluminal coronary angioplasty patients was 5.5 +/- 8.3 hours (range, 1-24 hr). The mean flow rate was 2.42 +/- 0.55 L/min (range, 1.5-3.0 L/ min). The overall 30-day survival rate was 61%. In our experience, the TandemHeart device was easy to insert and provided a means either to cardiac recovery or to continued support with an implantable left ventricular assist device.

Unprotected left main stent placement in a patient with Takayasu's arteritis: an unusual solution for an unusual disease.

We describe the case of a young woman with Takayasu's arteritis that initially manifested as heart failure due to left main coronary artery stenosis. The patient's occluded subclavian artery and the active inflammatory process of Takayasu's arteritis precluded coronary artery bypass grafting with the use of arterial grafts. Therefore, a drug-eluting stent was placed in the unprotected left main artery. This procedure resulted in the resolution of symptoms, with a patent stent and no new coronary lesions observed on 3-month angiography, and normal left ventricular function on 9-month echocardiography. We conclude that the use of drug-eluting stents may be an important treatment option for Takayasu's arteritis patients with life-threatening coronary artery disease for whom coronary artery bypass grafting is not an option.

Transcriptional regulators of ribosomal biogenesis are increased in the unloaded heart.

Mechanical unloading of the rat heart increases both protein synthesis and protein degradation. The transcriptional mechanism underlying increased protein synthesis during atrophic remodeling is not known. The aim of this study was to identify transcriptional regulators and the gene expression profile regulating protein synthesis in the unloaded rat heart and in the unloaded failing human heart. We measured DNA binding activity, transcript levels, and protein expression of transcriptional regulators of protein synthesis in a model of atrophic remodeling induced by heterotopic transplantation of the rat heart (duration 1 and 7 days). Using microarray analysis and quantitative RT-polymerase chain reaction, we found an increase in c-myc-regulated gene expression including an induction of ribosomal subunit messenger RNA's (RPS 10, RPL 21) and rRNA (18S). Consistent with the gene expression profile, DNA binding activity of c-myc and the nuclear protein concentration of its coactivator, upstream binding factor (UBF), increased in the atrophied heart whereas protein levels of the c-myc inhibitor MAD1 decreased. We found the same increase of ribosomal subunit messenger RNA and rRNA in 21 paired samples of failing human hearts obtained before and after left ventricular assist device treatment (mean duration: 157+/-31 days). In summary, mechanical unloading increases c-myc activity and c-myc-regulated gene expression in the rat heart. Changes in transcript levels of genes regulating ribosomal biogenesis in the unloaded rat heart resemble those found in the unloaded failing human heart. We concluded c-myc and c-myc-regulated gene expression are transcriptional regulators of protein synthesis during atrophic remodeling of the heart.

Mycotic pseudo-aneurysm of the ascending thoracic aorta after cardiac transplantation.

A large mycotic pseudo-aneurysm of the ascending thoracic aorta was found in a patient with empyema and infectious mediastinitis after an orthotopic heart transplant procedure. The patient underwent surgical resection of the pseudo-aneurysm with patch aortoplasty and was treated with appropriate long-term antibiotic therapy. The patient continues to do well 3 months after surgery. Early surgical intervention combined with pre-operative and prolonged post-operative antibiotic therapy and close follow-up is essential in these patients.

Use of a percutaneous ventricular assist device for treatment of cardiogenic shock due to critical aortic stenosis.

We present the case of a 72-year-old woman who was transferred to our institution in cardiogenic shock and with multiple-organ failure, due to critical aortic stenosis. She was considered too high-risk to undergo aortic valve replacement. A TandemHeart percutaneous ventricular assist device was used to stabilize the patient's condition before surgery, and she subsequently underwent successful aortic valve replacement. To our knowledge, this is the 1st report in the literature of this particular application of the TandemHeart device.

First use of the TandemHeart percutaneous left ventricular assist device as a short-term bridge to cardiac transplantation.

Advanced heart failure may be refractory despite aggressive support with inotropic agents and intra-aortic balloon pumping. Implantable left ventricular assist devices are increasingly being used as bridges to cardiac transplantation or as destination therapy because of the limited availability of donor organs. We report the 1st use of the TandemHeart percutaneous ventricular assist device as a short-term bridge to cardiac transplantation.

Left ventricular assist device therapy for end-stage congestive heart failure: from REMATCH to the future.

Therapy for patients with end-stage cardiomyopathy continues to evolve, but clearly it must now involve left ventricular assist device therapy as either bridge-to-transplantation or destination therapy. Patients who are selected for left ventricular assist device support must be able to undergo the surgical implantation procedure safely and avoid common complications such as right heart failure. Adequate patient selection is essential and can typically be accomplished using simple hemodynamic measures. As left ventricular assist device technology evolves, pulsatile devices will likely be replaced by their newer axial flow counterparts, which offer decided advantages. In the future, therapy for end-stage heart failure will involve aggressive use of mechanical assist device therapy and, as more patients are supported with these devices and the technology improves, this will become a burgeoning field for cardiologists and cardiovascular surgeons.