S. Klotz

Proof of concept: hemodynamic response to long-term partial ventricular support with the synergy pocket micro-pump

OBJECTIVESnThe purpose of this study was to test the hemodynamic effects of partial ventricular support in patients with advanced heart failure.nnnBACKGROUNDnThe use of current left ventricular assist devices (VADs) that provide full circulatory support is restricted to critically ill patients because of associated risks. Smaller, less-invasive devices could expand VAD use to a larger pool of less-sick patients but would pump less blood, providing only partial support.nnnMETHODSnThe Synergy Pocket Micro-pump device (CircuLite, Inc., Saddle Brook, New Jersey) pumps approximately 3.0 l/min, is implanted (off pump) via a mini-thoracotomy, and is positioned in a right subclavicular subcutaneous pocket (like a pacemaker). The inflow cannula inserts into the left atrium; the outflow graft connects to the right subclavian artery.nnnRESULTSnA total of 17 patients (14 men), age 53 +/- 9 years with ejection fraction 21 +/- 6%, mean arterial pressure 73 +/- 7 mm Hg, pulmonary capillary wedge pressure 29 +/- 6 mm Hg, and cardiac index 1.9 +/- 0.4 l/min/m(2) received an implant. Duration of support ranged from 6 to 213 (median 81) days. In addition to demonstration of significant acute hemodynamic improvements in the first day of support, 9 patients underwent follow-up right heart catheterization at 10.6 +/- 6 weeks. These patients showed significant increases in arterial pressure (67 +/- 8 mm Hg vs. 80 +/- 9 mm Hg, p = 0.01) and cardiac index (2.0 +/- 0.4 l/min/m(2) vs. 2.8 +/- 0.6 l/min/m(2), p = 0.01) with large reductions in pulmonary capillary wedge pressure (30 +/- 5 mm Hg vs. 18 +/- 5 mm Hg, p = 0.001).nnnCONCLUSIONSnPartial support appears to interrupt the progressive hemodynamic deterioration typical of late-stage heart failure. If proven safe and durable, this device could be used in a relatively large population of patients with severe heart failure who are not sick enough to justify use of currently available full support VADs. (Safety and Performance Evaluation of CircuLite Synergy; NCT00878527).

Left ventricular pressure and volume unloading during pulsatile versus nonpulsatile left ventricular assist device support

BACKGROUNDnNonpulsatile axial or centrifugal pumps are the latest generation of left ventricular assist devices (LVAD). Whether left ventricular (LV) unloading and outcome in these devices is similar to pulsatile LVADs during long-term support has not been investigated. We compared LV unloading and mortality between different types of LVAD support (pulsatile versus nonpulsatile).nnnMETHODSnIn 31 patients undergoing long-term LVAD implantation (nonpulsatile = 10, pulsatile = 21) preoperative and postoperative echocardiographic and hemodynamic assessment with right heart catheterization had been obtained.nnnRESULTSnAll patients had similar echocardiographic, hemodynamic, and clinical heart failure characteristics at baseline. The degree of LV pressure unloading was the same in both device types, caused by similar reduction of mean pulmonary pressure (18.6 +/- 5.1 versus 18.3 +/- 7.5 mm Hg) and pulmonary capillary wedge pressure (8.9 +/- 4.4 versus 8.0 +/- 7.0 mm Hg). Left ventricular volume unloading was pronounced with a pulsatile device owing to a statistically significant higher pump output (5.1 +/- 1.0 L/min) in comparison with nonpulsatile LVADs (3.6 +/- 0.9 L/min, p < 0.001). Echocardiographic-determined end-systolic indicators confirm this augmentation in pulsatile LVADs. Etiology or the time interval of hemodynamic reassessment had no impact in left ventricular pressure unloading, but LV volume unloading decreased between day 60 and 120 in patients with nonpulsatile LVADs. The preoperative and postoperative transplant mortality was comparable in both groups.nnnCONCLUSIONSnLeft ventricular pressure unloading is similar in patients with nonpulsatile as compared with pulsatile implantable long-term assist devices. Left ventricular volume unloading is pronounced in pulsatile LVADs.

Diagnosis and Treatment of Nonocclusive Mesenteric Ischemia After Open Heart Surgery

BACKGROUNDnAcute nonocclusive mesenteric ischemia (NOMI) is a rare but often fatal event after cardiac surgery.nnnMETHODSnTwenty patients with ongoing ileus after cardiac surgery despite maximal laxative treatment underwent selective mesenteric angiography. In cases of pathological radiographic findings, papaverine was continuously administered via an intraarterial perfusion catheter.nnnRESULTSnSevere NOMI was confirmed in seven patients (mean lactate: 6.9 +/- 8.3 mg/dL), mild to moderate findings in another seven (mean lactate: 1.4 +/- 1.1 mg/dL). One patient had thromboembolic occlusion of the superior mesenteric artery; five patients demonstrated normal imaging findings. In nine of fourteen patients (64%) treated with papaverine, symptoms improved within hours (defecation occurred after 4-29 hours, mean 13 +/- 8.1 hours). No side effects or complications occurred in connection with the papaverine treatment. The clinical condition of five patients deteriorated. Four patients underwent laparotomy with creation of an ileostomy or colostomy, two of whom presented with severe intestinal ischemia and later died. One patient died prior to laparotomy.nnnCONCLUSIONSnSelective mesenteric angiography with continuous papaverine administration is a simple, fast, and effective diagnostic and therapeutic tool to reduce the need for laparotomy for symptoms of ileus after open-heart surgery.

Reversible pulmonary hypertension in heart transplant candidates--pretransplant evaluation and outcome after orthotopic heart transplantation.

Heart transplantation is the most effective treatment for well‐selected patients with endstage heart failure. Unfortunately, transplant candidates with pulmonary hypertension (PHT) are often not considered for heart transplantation. This study was performed to assess the value of prostaglandin E1 (PG‐E1) for reduction of PHT and to predict the postoperative outcome, compared to patients without PHT.

Clinical benefits of partial circulatory support in New York Heart Association Class IIIB and Early Class IV patients

OBJECTIVEnFull mechanical support with a left-ventricular assist device (LVAD) is generally limited to end-stage heart-failure patients. We have been studying the safety and efficacy of the partial support Synergy® Pocket Micro-pump as bridge-to-transplant in a less-sick group of patients as a prelude to a study of its use for destination therapy.nnnMETHODSnThe CircuLite® Synergy device is implanted via a small right-sided thoracotomy with an inflow cannula in the left atrium and an outflow graft connected to the right subclavian artery without the use of extracorporeal circulation. The micro-pump is the size of an AA battery, sits in the pacemaker pocket subcutaneously in the right clavicular groove and pumps up to 3.0 l min⁻¹ from the left atrium to the right subclavian artery.nnnRESULTSnThe device has been implanted in 27 patients awaiting cardiac transplant (22 males), age 54.8 ± 10.0 years with ejection fraction (EF) 21 ± 6%, mean arterial pressure 73.5 ± 8.8 mm Hg, pulmonary capillary wedge pressure (PCWP) 27.5 ± 7.8 mm Hg and cardiac index (CI) 2.0 ± 0.4 l min⁻¹ m⁻². Duration of support has ranged from 6 to 281 days. Right-heart catheterization showed significant hemodynamic improvement in the short- and intermediate term after implant, with increases in CI from 2.0 ± 0.4 to 2.8 ± 0.6 l min⁻¹ m⁻² (p < 0.001) and reductions in PCWP from 28 ± 6 to 18 ± 7 mm Hg (p = 0.002) at an average of 9.5 ± 5.5 weeks.nnnCONCLUSIONSnThe Synergy device provides partial hemodynamic support and its use is associated with significantly improved hemodynamics, thus appearing to interrupt and partially reverse the progressive hemodynamic deterioration typical of end-stage heart failure. Ongoing efforts are aimed at demonstrating additional clinical benefits and continuing to further improve the risk/benefit ratio.

Partial mechanical long-term support with the CircuLite Synergy pump as bridge-to-transplant in congestive heart failure

BACKGROUNDnFull mechanical support with a left ventricular assist device (LVAD) is often limited to very sick patients, as the only survival option. This European multicenter study analyzes the effect of partial mechanical support as bridge-to-transplant in a less sick heart failure patient group.nnnMETHODSnThe CircuLite Synergy device is implanted via a small right-sided thoracotomy with an inflow cannula in the left atrium and an outflow graft connected to the right subclavian artery without the use of extracorporeal circulation. The pump itself sits in a pacemaker pocket subcutaneously in the right clavicular groove. It is able to pump up to 3.0 l/min and partially unload the left ventricle.nnnRESULTSnThe device was implanted in 25 patients on the cardiac transplant waiting list (20 males), aged 55.5 +/- 9.6 yrs with an ejection fraction of 21.6 +/- 6.0 %, a mean arterial pressure of 73.5 +/- 8.5 mmHg, a pulmonary capillary wedge pressure of 27.2 +/- 7.8 mmHg and cardiac index of 1.9 +/- 0.4 l/min/m (2). Duration of support ranged from 6 to 238 days. Right heart catheterization showed significant hemodynamic improvement in the short- and intermediate-term after implantation with increases in arterial pressure from 72.6 +/- 11.0 to 79.4 +/- 8.6 mmHg ( P = 0.04) and in cardiac index from 2.0 +/- 0.4 to 2.7 +/- 0.6 l/min/m (2) ( P = 0.003) with a reduction in pulmonary capillary wedge pressure from 28.5 +/- 6.0 to 19.7 +/- 6.9 mmHg ( P = 0.012).nnnCONCLUSIONSnThe CircuLite Synergy device is a partial support pump, which is easy to implant and which provides hemodynamic benefits in bridging heart failure patients to cardiac transplant.

Thoracic aortic stent graft: comparison of contrast-enhanced MR angiography and CT angiography in the follow-up: initial results

Abstract.The objective of this study was to compare contrast-enhanced magnetic resonance angiography (CE MRA) and multislice computed tomographic angiography (MS CTA) in the follow-up of thoracic stent-graft placement. The CE MRA and MS CTA were performed following nitinol stent-graft treatment due to thoracic aneurysm (n=4), intramural bleeding (n=2) and type-B aortic dissection (n=5). Corresponding evaluation of arterial-phase imaging characteristics focused on the stent-graft morphology and leakage assessment. Stent-graft and aneurysm extensions were comparable between both techniques. Complete exclusion (aneurysm, n=4; dissection, n=2) was assessed with high confidence with CE MRA and MS CTA. Incomplete exclusion (intramural bleeding, n=2; dissection, n=3) was assigned to lower confidence scores on CE MRA compared with MS CTA. On CE MRA the stent-graft lumen demonstrated an inhomogeneous signal, the stent struts could not be assessed. The CE MRA can be used as alternative non-invasive imaging for follow-up of nitinol stent grafts. Arterial-phase leak assessment can be less evident in CE MRA compared with MS CTA studies; therefore, the use of late-phase imaging seems to be necessary. The diagnostic gap of stent-graft fracture evaluation using MRA may be filled with plain radiographs.

False aneurysm of ascending aorta-anastomosis after orthotopic heart transplantation

We operated a 49-year-old man 4 years after orthotopic heart-transplantation with a false aneurysm due to a 2 cm dehiscence between the anastomosis of the recipient and donor ascending aorta (Fig. 1). Prior to transplantation, the patient was bridged with a Novacor-LVAD due to ischemic cardiomyopathy. There were no signs of infection during LVAD-explant. The partly thrombosed aneurysm was treated by interposition of a 22-mm-dacron tube-graft with reinsertion of the brachiocephalic truncus using a 10mm-dacron-prothesis under CBP and hypothermic circulatory arrest. We find no aspects for a mycotic aneurysm. The reason was probably a slowly acquiring post-transplant arterial hypertension. At postoperative day (POD) 20, the patient was discharged after uneventful postoperative course. Postoperative CT-scans showed regular anastomosis (Fig. 2). European Journal of Cardio-thoracic Surgery 20 (2001) 847

Twiddler-Syndrom – Keine Erkrankung des alten Patienten

Summary Rotation of the pulse generator around the electrode, also referred to as Twiddlers syndrome, is a rare complication after permanent pacemaker implantation which can lead to partial or total pacing failure. We present a 32 year old heart transplanted man with Twiddlers syndrome three years after implantation of a subpectorally placed pacemaker. Predisposing factors, options for preventing and treatment are discussed.Zusammenfassung Das Twiddler-Syndrom, definiert als die Rotation des Herzschrittmacheraggregates um die Elektrode, ist eine seltene Komplikation, die aber zur partiellen oder kompletten Schrittmacheroder Elektrodendysfunktion führen kann. Wir berichten über einen 32-jährigen herztransplantierten Patienten mit einem Twiddler-Syndrom drei Jahre nach Implantation eines subpektoral gelegenen Herzschrittmachers. Prädisponierende Faktoren, präventive und mögliche therapeutischen Maßnahmen werden diskutiert.

A Decision Tree for the Replacement of the Ascending Aorta in Patients Undergoing Aortic Valve Surgery: A Single Center Experience in 1362 Patients

Objective: The management of the ascending aorta (AA) of diameters between 40 and 50u2009mm in patients undergoing aortic valve surgery is controversial. We present our experience and factors that influence our decision to replace or repair the ascending aorta in 1362 patients undergoing aortic valve surgery. Methods: 1362 patients (1044 male) undergoing aortic valve surgery were retrospectively analyzed. Mean follow up was 5.4u2009±u20093.6 years (range: 0–14 years, 7334 patient-years) and 96.5% complete. The individualized AA management decision process included mainly the AA diameter, age, body surface area, presence and type of bicuspid aortic valve (BAV) as well as subjective factors such as the macroscopic AA configuration and the perceived tissue strength of the aortic wall. Three AA treatment groups were included in the analysis: no intervention, and intervention either by aortoplasty (AoP) or AA replacement (AAR). Recursive partitioning techniques using conditional inferences trees were used to investigate our AA decision process, how the effect of input variables (AA diameter, age, body surface area (BSA), BAV type) influenced this decision process, and the resulting patterns of AA intervention Results: In 66.5% of the patients (nu2009=u2009906) no intervention was performed, in 12.6% (nu2009=u2009172) an AoP and in 20.9 (nu2009=u2009284) an AAR. Hospital mortality was 1.1% for no intervention, 0.6% for AoP and 0.4% for AAR (pu2009=u20090.4). 10 year survival was similar for all three groups and was comparable to that of the general population. Factors that exhibited a statistical significantly influence on our decision process to replace or repair the ascending aorta included: absolute ascending aorta diameter, BSA, presence of BAV and age (pu2009<u20090.01 for all). Conclusion: Our results indicate that the decision to repair or replace the ascending aorta of diameters between 40–50u2009mm is highly individualized and is influenced by patient related factors such as absolute ascending aorta diameter, body surface area, BAV type and age. Despite this being a retrospective analysis, our results point out that this individualized approach leads to excellent results in terms of durability, survival and morbidity. Longer-term follow-up in a prospective fashion is necessary to consolidate these conclusions.