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Ascending aorta manipulation during on-pump coronary artery bypass grafting (CABG) surgery can release embolic matter and may cause stroke. Strategies for lowering the stroke rate associated with coronary artery bypass grafting surgery include off-pump surgery without cardiopulmonary bypass and pump-assisted surgery with minimal aortic manipulation (i.e., without aortic cross-clamping). We examined whether one approach is superior to the other in reducing stroke and perioperative mortality rates.We reviewed consecutive elective, urgent, and emergency off-pump/no-bypass and pump-assisted/no-clamp coronary artery bypass grafting procedures performed by a single surgeon at our institution from June 2011 through October 2017.Of 570 patients analyzed, 395 (69.3%) underwent off-pump/no-bypass surgery, 43 (7.5%) underwent pump-assisted/no-clamp surgery, and 132 (23.2%) transitioned mid-procedure from off-pump/no-bypass to pump-assisted/no-clamp surgery. Patients who were70 years old, were female, or had diabetes, cardiomegaly, or a history of myocardial infarction or congestive heart failure were more likely to undergo pump-assisted/no-clamp surgery or the combined technique. None of the pump-assisted/no-clamp patients had a stroke, versus 0.3% of the off-pump/no-bypass patients and 0.8% of the combination patients. Stroke and in-hospital mortality rates did not differ by technique.A hybrid strategy incorporating off-pump, pump-assisted, and combined off-pump/pump-assisted techniques achieved very low stroke rates in patients undergoing coronary revascularization. Perioperative mortality was similar for all three techniques. Avoiding aortic clamping may be crucial for decreasing CABG-related stroke rates. Off-pump/no-bypass surgery had no significant advantage over the pump-assisted/no-clamp or combined techniques in reducing the stroke rate after coronary artery bypass grafting surgery.

We report the long-term survival of a 46-year-old man supported with a HeartMate II continuous-flow left ventricular assist device after complex repair of a bicuspid aortic valve, anomalous left main coronary artery, and dilated aorta. He has been maintained on an anticoagulation regimen of warfarin and low-dose aspirin without problems for 10 years, during which he has worked continuously and productively. Device flow has been kept at 10,000 rpm. Possible contributors to this long-term success include proper alignment of the device inflow cannula, pericardial patch closure of the left ventricular outflow tract, and, notably, the remarkable freedom from mechanical failure of the continuous-flow left ventricular assist device. Whether the higher flow rate produced by the pericardial patch closure contributes to pump longevity is unknown and merits further investigation.

Introduction: The incidence of left ventricular assist device (LVAD) implantation in heart failure (HF) patients across various racial groups has not been examined in large databases. We present an analysis of racial groups and LVAD implantation using a large US database. Methods: We analyzed data from a commercial and a national Medicare database using OPTUM® Clinformatic® Data Mart and a Medicare National Sample that comprised 57,585,519 US patients. We identified 346,345 adults with HF from 2014 to 2016. Comorbidities were identified including diabetes, coronary artery disease, hypertension, and cardiomyopathy. Data were collected for LVAD implantation, stroke, cerebral injury, mechanical ventilation, heart transplantation, renal insufficiency, and death through 2019 or until they were no longer enrolled. Race, sex, and age were discerned from enrollment information. Results: The incidence of HF was similar across all 5 racial groups (Table). Age at the time of HF diagnosis and LVAD implantation was lower in Blacks than in other races. LVADs were implanted at a higher rate in Blacks than in other groups. Age at LVAD implantation was lower in black men than in men of other races. Whites had a lower incidence of stroke, intracranial bleed, and cerebral injury after LVAD implantation than did Blacks, Hispanics, and Native Americans. The rate of eventual transplantation was similar among all groups. Because of the large database population analyzed, differences between groups were highly significant, with p Conclusions: In the largest US database analysis to date, we found that US racial groups showed no significant differences in the incidence of HF, rate of LVAD implantation, survival after LVAD implantation, or progression to cardiac transplantation. However, Blacks were diagnosed with HF and underwent LVAD implantation at somewhat younger ages than other groups.

We examined the hemodynamic effects of a new, implantable, direct cardiac assist device in an ovine heart failure model.The device, which encompasses both left and right ventricles, is inserted through the pericardial apex and self-expands to encompass the heart without suturing. The intact pericardium anchors the device in place. The device has 2 concentric chamber layers: an internal chamber layer filled with fluid to conform to the heart and an external chamber layer filled with air that provides external compression and negative pressure to aid relaxation.The device was implanted in 7 sheep with heart failure induced by microsphere embolization. Cardiac performance was assessed for 6 to 8 hours. The cardiac assist device provided cardiac systolic and diastolic assistance, as shown by pressure tracings of the left ventricle and aorta, pulmonary artery flow, and +dP/dt. Central venous pressure decreased during cardiac assistance. No anatomic damage was noted postmortem.Systolic and diastolic cardiac assistance can be achieved with this device that compresses and relaxes in synchrony with the native cardiac cycle.

Continuous-flow left ventricular assist devices have proved to be effective, durable, life-saving tools in patients with end-stage heart failure. However, because of the risks associated with mechanical circulatory support (including stroke, infection, gastrointestinal bleeding, and device malfunction), the optimal goal of device therapy is myocardial recovery and device removal. Ventricular reconditioning and pump explantation after continuous-flow support have been reported; however, little is known about variables that govern the pace and degree of myocardial response in patients who experience such recovery. We describe our long-term pump-weaning strategy for a 25-year-old man who had a continuous-flow device implanted and then needed more than 5 years of support from it before developing cardiac reserve sufficient to enable pump explantation. To our knowledge, this is the longest period of uninterrupted continuous-flow device support to end in successful pump deactivation and a return to medical therapy. This case highlights the importance of actively and persistently pursuing a device-weaning strategy in all patients who need left ventricular assist device therapy.

OBJECTIVES Dialysis is considered a contraindication to continuous-flow left ventricular assist device (CF-LVAD) implantation. We evaluated clinical outcomes and survival in carefully selected, low-risk patients with renal failure who required dialysis before CF-LVAD implantation. METHODS We extracted medical record data of patients who underwent CF-LVAD placement at our centre between 1 January 2006 and 31 August 2017, with 2 clinical scenarios: those who required long-term (>14 days) dialysis and those who required short-term (≤14 days) dialysis immediately before implantation. Demographic, clinical and intraoperative characteristics and survival outcomes were assessed. RESULTS Of 621 patients who underwent CF-LVAD implantation during the study period, 31 underwent dialysis beforehand. Of these, 17 required long-term dialysis (13 haemodialysis, 4 peritoneal dialysis), and 14 underwent short-term haemodialysis. Compared with the long-term dialysis patients, the short-term dialysis patients were more likely to be Interagency Registry for Mechanically Assisted Circulatory Support profile 1–2 (92.9% vs 70.6%; P CONCLUSIONS Carefully selected patients who are stable on long-term dialysis have acceptable survival rates after CF-LVAD implantation. Patients with acute renal failure had much poorer outcomes than those with chronic end-stage renal disease.

Purpose Diastolic mechanical cardiac assist has been difficult to provide. We examined the hemodynamic effects of a new, implantable cardiac assist system on ovine cardiac performance. The device is inserted via the apex of the pericardium. It encompasses and encircles both left and right ventricles. The device self-expands to encompass the heart without suturing; it is held in place by the pericardium. There are 2 concentric chambers. An internal chamber is saline-filled and conforms to the heart. An external chamber is air-filled and provides external compression followed by negative pressure to aid with relaxation. (See figure). Device compression and relaxation is EKG-triggered. Methods The device was implanted in 7 sheep with heart failure induced by microsphere embolization. Cardiac performance was assessed for 6-8 hours. Invasive monitoring with a Swan-Ganz catheter, LV catheter, and flow probes provided data on cardiac function. Results Initiation of cardiac assist resulted in increased cardiac output of up to 0.7 L/min (21% increase). Systolic BP increased by 15 mmHg (22% increase). Mean pulmonary artery pressure decreased by 3 mmHg (10% decrease). Filling pressures declined indicating ventricular and pulmonary artery unloading. Diastolic pulmonary pressure declined by 7mmHg on average (from 23mmHg to 16 mmHg; -30%). LVEDP declined from 17 mmHg to 13 mmHg. Increased -dP/dt was dramatic after device activation (see figure) Conclusion Diastolic, and systolic, cardiac assistance can be achieved with a new implantable device that encompasses the heart compressing and relaxing sequentially in an ovine model of heart failure.

Purpose All current short-term mechanical cardiac assist devices are placed intravascularly and are associated with relatively high rates of thrombosis and infection. We examined a non-blood-contacting extracardiac device that can be inserted with a minimally invasive technique. Methods The CorInnova cardiac assist device consists of 2 polyurethane chambers and a nitinol wire frame. It surrounds the left and right ventricles (fig 1). Its low-profile allows actuation within the pericardium. Air chambers pressurize cyclically to compress the heart during systole. Minimally invasive implantation was assessed in ovine studies. In a beating-heart procedure under general anesthesia, cardiac access was via a 2-3 inch subxiphoid incision. A small pericardial incision was made at the cardiac apex. Under fluoroscopy, the device was advanced to surround the ventricles within the pericardial space (fig 2). After chest closure, fluid was infused into the device's innermost chamber to conform the device to the epicardium. Results Minimally invasive deployment and attachment was successful for 55 devices in 25 acute studies. No animal sustained any cardiac injury as confirmed by necropsy. The wire frame allowed the device to self-flare around the heart. The intact pericardium kept the device intimately attached to the myocardium. Device-heart coupling was enhanced by the fluid chamber. This feature was verified in several (25+) acute studies and one 5-day study as documented by fluoroscopic imaging and subsequent explant. Conclusion A novel extracardiac assist device can be placed safely using a minimally invasive procedure.

Driveline infection has been a persistent problem with mechanical cardiac assist devices. The reported incidence of infection has been low in patients who receive a Jarvik 2000 continuous-flow left ventricular assist device when a skull-pedestal driveline exit site is used. We evaluated whether this is also true when a subcostal driveline exit site is used. We reviewed baseline demographic variables, postimplantation vital signs, laboratory values, and culture results in patients who underwent Jarvik 2000 implantation at our center from April 2000 through October 2009, including follow-up through June 2014. All patients had a subcostal driveline exit site. We defined device-related infection as a positive blood or wound culture associated with a medical or surgical device intervention. Event and time-to-event rates were calculated. Eighty-one patients received 89 Jarvik 2000 devices, all as bridges to transplantation. The median support duration was 69 days (interquartile range, 27–153 d; range, 2–2,249 d). Five superficial driveline infections and one incision-site infection occurred (0.002 events per patient-year of support). The median time from pump implantation to onset of driveline infection was 30 days; the incision-related infection occurred at 44 days. The Jarvik 2000 has a low incidence of infection when implanted with use of a subcostal driveline exit site. The incidence of pump infections is particularly low. Using a subcostal driveline exit site may be as effective in preventing infections as using a skull-pedestal driveline exit site. We detail our findings in this report.

Purpose Continuous-flow LVADs (CF-LVADs) have been implanted for both bridge-to-transplant and for destination therapy. Extended survival with CF-LVADs has not been completely examined. We examined the likelihood of surviving more than 5 to 10 years with a CF-LVAD Methods We reviewed the 198 patients alive and currently being followed at our institution after CF-LVAD implantation. Patients were stratified as to type of pump implanted (HeartMate 2, HeartWare, or HeartMate 3), reason for implantation (Bridge-to-transplant or destination therapy), and length of survival ( 10 years). Results Seven (7) of the 198 patients being followed had a CF-LVAD in place and functioning for more than 10 years. 4 of these 7 patients surviving more than 10 years had not required pump exchange. There were 18 patients being followed with a CF-LVAD in place for 5-10 years. There were 173 being followed with a CF-LVAD in place for Of the 7 patients with a CF-LVAD in place >10 years, 6 were HeartMate 2 (HM2) CF-LVADs and one was a HeartWare (HW). Five (5) of the 7 patients with a CF-LVAD in place >10 years had the LVAD implanted as a bridge-to-transplant. Of the 18 patients with a CF-LVAD in place for 5-10 years, 9 had a HM2, 8 had a HW, and 1 had a HeartMate3 (HM3). The CF LVAD was implanted as a bridge-to-transplant in 5 of the 18 patients Conclusion Prolonged survival after CF-LVAD implantation is increasingly likely. A substantial number of patients with a CF-LVAD in place for more than 5 years originally had the device implanted as a bridge-to-transplant.

Pump-assisted (PACAB) and off-pump (OPCAB) coronary artery bypass grafting (CABG) without cross-clamping and hypothermic cardiac arrest are important techniques in minimal-access procedures and in patients with poor preoperative cardiac function, yet their effects on postoperative cardiac function

Purpose Infection is a frequent problem following CF-LVAD implantation. We were interested in determining the spectrum of infectious complications following implantation of HeartMate II (HMII) and Heartware (HW) CF-LVADs. Methods We reviewed 893 HMII and HW implants from 1999 to 2018 performed at our institution. Infections were classified as device-specific (superficial/deep driveline infection or pocket/device infection) or as device-related (bacteremia). Other infections, such as urinary tract infections, central line infections, and pneumonia were recorded, but are not analyzed here. Etiology of the infection was also recorded. In some infections, multiple infectious agents were cultured. Results 801 CF-LVADs were implanted; 542 HMIIs, and 256 HWs. 180/542 (33.2%) of HMII, and 70/256 (27.3%) of HW pumps developed an infection. The incidence of infection / support year was 20.6% for HMII pumps and 20.3% for HW pumps. Driveline infections (superficial or deep) occurred in 136/542 (25.1%) HMII implants and in 53/250 (21.2%) HW implants. Pocket/device infections occurred in 102/542 (18,8%) HMII pumps and in 23/256 (9.0%) HW pumps. Bacteremia occurred in 84/542 (15.1%) HMII pumps and in 28/256 (10.9%) HW pumps. Staph aureus, pseudomonas, and coagulase negative species were the most common isolates (see Table). Median time to first infection was not statistically different (p=748) between HMII (1021 days) and HW devices (1273 days); (See Figure). Conclusion Infection continues to be a major problem after CF-LVAD implantation. Driveline infections, both superficial and deep, as well as pocket and device infections occur commonly after both HMII and HW implants.

Heart failure is a common and growing cause of death in the Western world. Mechanical cardiac assist devices are being used with increasing frequency to treat this disorder. Results are have been promising. Continuous-flow pump technology has largely replaced the older pulsatile-flow technology. However, continuous-flow devices have several long-term potential complications that occur after the initial perioperative implantation which still limit their use. The commonest potential complications include pump thrombosis, the need for pump replacement, stroke, thromboembolic events, bleeding, and infection. The etiology of these complications is becoming increasingly well understood. This chapter will review these complications, their etiology, and treatment.

The HeartMate II is a continuous-flow left ventricular assist device that can be explanted from patients after cardiac recovery. We implanted a HeartMate II in a 21-year-old man who had idiopathic cardiomyopathy. A year later, he developed thyrotoxicosis, presumably secondary to amiodarone administered for ventricular fibrillation. Four months after the diagnosis of thyrotoxicosis, thyroid hormone levels had returned to normal, and native cardiac function had improved remarkably. After a support period of 24 months, the HeartMate II was explanted. Six years later, the patient continues to be in New York Heart Association functional Class I. Amiodarone-induced thyrotoxicosis may have contributed to myocardial recovery.

Background Percutaneous mitral repair with the MitraClip device (Evalve, Menlo Park, CA) has been reported. Preserving conventional surgical options in the event of percutaneous treatment failure is important. We describe surgical treatment at varying intervals after the MitraClip procedure in 32 patients. Methods One hundred seven patients with moderate-to-severe or severe mitral regurgitation who were either symptomatic (91%) or, if asymptomatic (9%), had evidence of left ventricular dysfunction were enrolled as part of the Endovascular Valve Edge-to-Edge REpair STudy (EVEREST) phase I registry study or as "roll-in" subjects in the EVEREST II study. Thirty-two of the 107 patients (30%) underwent surgery after an attempted MitraClip procedure. Results Of the 32 patients undergoing post-clip mitral valve surgery, 23 patients (72%) had one or more clips implanted and 9 patients (28%) received no clip implant. The indications for mitral valve surgery in the 23 patients with a clip included partial clip detachment (n = 10), residual or recurrent mitral regurgitation greater than 2+ (n = 9), and other (atrial septal defect [n = 2], device malfunction [n = 1], and incorrectly diagnosed mitral stenosis [n = 1]). Twenty-seven of 31 patients (87%) underwent the surgical procedure planned before surgery (planned procedure unknown in 1 patient). Four of 25 patients (16%) with planned repair underwent mitral valve replacement. Conclusions Standard surgical options were preserved in patients who had surgery after percutaneous repair with the MitraClip device. Successful repair was feasible in the majority of patients after the MitraClip procedure, with repair performed as late as 18 months after clip implantation.

The Jarvik 2000 axial flow left ventricular assist device (LVAD), under development for the past decade, has the potential to support patients temporarily until cardiac transplantation or as a permanent circulatory support, without the size limitations of other implantable systems.To assess its ability to perfuse the kidneys and liver, we monitored renal and hepatic function in 10 patients who received the Jarvik 2000 LVAD as a bridge to transplantation. Left ventricular assistance was maintained for up to 214 days (6 months), and renal and hepatic function were monitored at least weekly.Renal function before LVAD implantation in these patients was normal in 7 (creatinine,1.5) and moderately impaired in 3 (creatinine, 1.2 to 2.0). Hepatic function was normal in 7 patients before LVAD implantation (total bilirubin1.2; serum glutamic-oxaloacetic transaminase (SGOT),40; serum glutamic-pyruvic transaminase (SGPT),50) and normal at the time of transplantation in all 10 patients. Of the 3 patients with abnormal hepatic function before LVAD implantation, 1 patient had also had moderate renal dysfunction.Despite reduced pulsatility, the Jarvik 2000 LVAD improves or maintains excellent renal and hepatic function during periods of circulatory assistance in patients awaiting transplantation.

Background: Ultraprofound hypothermia may have a place in trauma rescue and resuscitation. We describe resuscitation of dogs after asanguhteous perfusion and circulatory arrest of 2 hours at 2° to 4°C. Methods: Nine dogs were cooled using a bypass apparatus and their circulating blood replaced with bicarbonated Hextend (Abbott, North Chicago, IL). Perfusion was continued to 2° to 4°C, and 60 mL of 2 mol/L KCl and 20 mL of 50% MgSO 4 .7H 2 O were infused intra-arterially, and circulation was arrested for 2 hours. The dogs were then rewarmed, transfused, defibrillated, weaned from bypass, and allowed to awaken. Preoperative and postoperative biochemistry and hematology were compared. Results: Six dogs recovered fully. One of these dogs died of an infection 2 weeks later. Three other dogs never recovered because of technical or procedural difficulties. Biochemical and hematologic parameters were normal by 3 weeks. Conclusion: Hypothermic blood substitution with Hextend allows resuscitation after 2 hours of ice-cold circulatory arrest in dogs.

Background —Alterations in adrenergic receptor densities can potentially contribute to myocardial dysfunction. Their relevance to myocardial hibernation in humans is unknown. Methods and Results —Accordingly, 22 transmural myocardial biopsies were obtained in 11 patients with ischemic ventricular dysfunction during bypass surgery, guided by transesophageal echocardiography. Patients underwent dobutamine echocardiography (DE) and rest scintigraphic studies before revascularization and DE at 3 to 4 months. α- and β-receptor density (ARD and BRD) and extent of fibrosis were quantified from the myocardial biopsies. Of the 22 segments, 16 had abnormal rest function and 6 were normal. Severely hypokinetic or akinetic segments showed a 2.4-fold increase in ARD with a concomitant 50% decrease in BRD compared with normal segments. An increase in ARD, a decrease in BRD to a lesser extent, and thus an increase in ARD/BRD ratio were seen in dysfunctional segments with contractile reserve compared with normal segments and were most pronounced in those without contractile reserve ( P r =0.37 and −0.39, respectively). Conclusions —Thus, graded and reciprocal changes in α- and β-adrenergic receptor densities occur in viable, hibernating myocardium and may account in part for the observed depression in resting myocardial function and preserved contractile reserve in this entity.

OBJECTIVESWe sought to evaluate the relation of segmental tissue Doppler (TD) velocities to both the regional amount of interstitial fibrosis and the myocyte beta-adrenergic receptor density in humans.BACKGROUNDThe systolic myocardial velocity (Sm) and early diastolic myocardial velocity (Em) acquired by TD are promising new indexes of left ventricular function. However, their structural and functional correlates in humans are still unknown.METHODSTen patients with coronary artery disease underwent echocardiographic examination including TD imaging, along with transmural endomyocardial biopsy at the time of coronary bypass surgery (two biopsies per patient for a total of 20 specimens). The specimens were analyzed for percent interstitial fibrosis and beta-adrenergic receptor density.RESULTSNormal segments (n = 8) had a higher beta-adrenoceptor density (2,280 ± 738 vs. 1,373 ± 460, p = 0.03) and a lower amount of interstitial fibrosis (13 ± 3.3% vs. 28 ± 11.5%, p = 0.002) than dysfunctional segments (n = 12). Myocardial systolic velocity and Em were also significantly higher (9.5 ± 2.7 vs. 5.9 ± 1.8 cm/s, p = 0.025 and 11.3 ± 2.8 vs. 6.4 ± 2.1 cm/s, p = 0.002, respectively) in normal segments. A significant relationship was present between Em and the beta-adrenergic receptor density (r = 0.78, p < 0.001) and percent interstitial fibrosis (r = −0.7, p = 0.0026), which together accounted for 81% of the variance observed in Em. Likewise, a significant relationship was present between Sm and the beta-adrenergic receptor density (r = 0.68, p < 0.001) and the percent interstitial fibrosis (r = −0.66, p = 0.004) and together accounted for 62% of the variance observed in Sm.CONCLUSIONSSystolic myocardial velocity and Em are strongly dependent on both the number of myocytes and the myocardial beta-adrenergic receptor density.

Bacterial endocarditis is an important cause of cardiac valvular problems. The diagnosis of bacterial endocarditis can be difficult, and, often, an aggressive clinical evaluation including serial blood cultures is necessary. The pathophysiology of endocarditis is changing with the rise of intravenous drug use; staphylococci are an increasingly common cause. Endocarditis often warrants surgical intervention. Operations for bacterial endocarditis range from valve repair to valve replacement to homograft replacement. The operations are technically challenging, but new methods of myocardial protection have markedly improved the surgical outcomes. Valve excision is an option for intravenous drug users with tricuspid valve endocarditis. Surgical management of endocarditis is a technically challenging but rewarding procedure that should be offered to appropriate patients.

Background . The results of pulmonary transplantation are compromised by acute and chronic rejection. We hypothesized that a liposomal form of aerosolized cyclosporine A (CsA) would be selectively deposited and concentrated in the lungs. The theoretical advantage of this therapy is selective pulmonary immunosuppression with prolonged utilization. Methods . Eighteen dogs were endotracheally intubated; aerosolized liposomal CsA was administered for 15 min. CsA levels were measured in whole blood, lung, trachea, heart, kidney, liver, and spleen at various times after treatment. Results . The lung rapidly absorbs aerosolized liposomal CsA; other organs have much lower concentrations. The retention of pulmonary CsA delivered by liposome aerosol is approximately 120 min in this model. Conclusions . Aerosolized liposomal CsA is selectively deposited and concentrated in the lungs; other organs absorb less CsA.

Background —Although dobutamine echocardiography (DE) is widely used to assess myocardial viability in humans, little is known about the relation between contractile reserve and myocardial structure. Methods and Results —We evaluated 20 patients with coronary disease (64±13 years old, ejection fraction 28±7.5%) with DE (up to 40 μg · kg −1 · min −1 ), rest-redistribution 201 Tl single photon emission CT, and quantitative angiography before bypass surgery. During surgery, patients underwent transmural myocardial biopsies (n=37) guided by transesophageal echocardiography to determine the extent of interstitial fibrosis and intracellular and interstitial proteins by histopathology and immunohistochemistry. Among the 37 segments biopsied, 16 recovered function as assessed 2 to 3 months later. Segments with postoperative functional recovery had more wall thickening at low-dose DE (28% versus 3%, P P =0.03), and less interstitial fibrosis (2% versus 28%, P P P P =0.016), and higher thallium uptake (64% versus 35.5%, P P =0.005). Thickening at low-dose DE correlated well with the extent of interstitial fibrosis ( r =−0.83, P Conclusions —Contractile reserve during DE correlates inversely with the extent of interstitial fibrosis and the amount of fibronectin and vimentin and directly with rest-redistribution thallium uptake.

Background . During the past 2 years, the development of a totally implantable biventricular bypass rotary blood pump system has been made. Methods . An extracorporeal gyro centrifugal pump, the CIE3, was miniaturized and developed into the PI601, a totally implantable plastic pump. Two-day anatomic and hemodynamic feasibility studies demonstrated that these two pump systems were easily implantable inside a calf's abdominal wall, directly under the diaphragm. The priming volume of the pump was 20 mL, with sufficient cardiac outputs at approximately 2,000 rpm and requiring less than 10 W of power. Two-week antithrombogenic screening tests also revealed these pump systems to be quite antithrombogenic. In addition, 1-month system reliability studies demonstrated fail-safe reliable performances. Results and Conclusions . Encouraged by these preliminary studies, the PI601 model was converted to the permanently implantable titanium gyro pump PI702 model. The long-term implantations were initiated approximately 3 months ago, and two such long-term LVAD studies are currently underway with no sign of difficulty (October 10, 1997). They were followed 283 days and 72 days, respectively. Both terminated due to functional inflow obstruction. There were no blood clots or emboli at autopsy.

Left ventricular free wall rupture is the third leading complication and the second most common cause of death after myocardial infarction. Its occurrence has been considered an unpredictable event usually leading to death. An increased appreciation for the clinical presentation of this syndrome and the nearly ubiquitous use of echocardiography have fostered a rise in the antemortem diagnosis of left ventricular free wall rupture, allowing the possibility of operative repair. Despite the increased reporting of left ventricular free wall rupture, the experience of any one surgeon or surgical group tends to be quite small. We review the current status of rupture prediction, clinical presentation, diagnosis, and treatment options. A recent case of left ventricular free wall rupture referred to the Baylor Cardiothoracic Surgery Group with the misdiagnosis of ruptured dissection of the ascending thoracic aorta is presented to illustrate our approach to this clinical situation.

Objective:We reviewed our experience of 343 descending and thoracoabdominal aortic aneurysm repairs to determine the impact of the adjuncts distal aortic perfusion and cerebral spinal fluid drainage on neurological deficit and death.Materials and Methods:Between January 1991 and March 1996, 104 (30%) patients were operated for thoracoabdominal aortic aneurysm type I, 118 (34%) for type II, 68 (20%) for type III or type IV, and 53 (15%) for descending thoracic type. Before September 1992, simple cross-clamp was used for 94 (27%) patients. After September 1992, adjuncts were used for 186 (54%) patients.Results:Overall neurological deficit was 33/343 (10%). Neurological deficit for simple cross-clamp patients compared to adjunct patients was 15/94 (16%) vs. 12/186 (7%) (O.R. 0.36, p

In this concluding article, the authors review the "take-home" messages from each ofthe preceding articles and integrate the information on each of the advanced treatment options into a set of overall guidelines for treatment selection.

Although current efforts at cardiomyoplasty have not produced the anticipated clear-cut benefits in cardiac function, replicable improvements in subjective function have resulted. Efforts at optimizing conditioning protocols, skeletal muscle strength, and timing of skeletal muscle assist devices should provide further improvements in cardiomyoplasty. Further work with alternative ways of configuring skeletal muscle for cardiac assist is extremely promising.

Left ventricular reconstruction is advocated as a surgical option for patients with severe congestive heart failure. Despite initial enthusiasm for this procedure, reports of long-term results are sparse. Herein, we describe a particularly gratifying case of left ventricular reconstruction in a 43-year-old man, who continues to have excellent left ventricular function 10 years postoperatively. This approach may be a reasonable alternative to cardiac transplantation in patients who lack other treatment options.

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.

Donor pretreatment with prostaglandin E1 as a pulmonary vasodilator has developed as a simple, effective means to provide excellent preservation in heart-lung transplantation. This study was undertaken to investigate the degree of ultrastructural preservation of the lung with prostaglandin E1 and other pulmonary vasodilators in a primate heart-lung transplantation model. Heart-lung transplantation was performed in 14 African green monkeys. Donor cardiac preservation was achieved with cold crystalloid cardioplegic solution (10 ml/kg). Lung preservation was achieved with cold, modified Euro-Collins solution delivered into the main pulmonary artery (60 ml/kg total). Vasodilator agents were administered intravenously 15 minutes before aortic crossclamping. The heart-lung grafts were stored at 4 degrees C for 6 hours. Three groups of animals were studied: five donors with prostaglandin E1 (0.1 to 4.0 micrograms/kg per minute), five donors with prostacyclin (0.1 to 0.35 micrograms/kg per minute), and four donors with nitroprusside (0.8 to 5.0 micrograms/kg per minute). After transplantation, arterial blood gas measurements and lung biopsies were performed at 1- and 3-hour intervals. Five formalin blocks per specimen were sectioned for hematoxylin and eosin staining. Cellular preservation and endothelial cell swelling were evaluated with electron microscopy. The specimens were graded for alveolar hemorrhage, endothelial cell swelling, and cellular preservation (grade 0, minimal, to grade 3, severe) and a mean score was obtained for each preservative agent. Prostaglandin E1-treated specimens demonstrated the least amount of endothelial swelling (mean score of 1.0) compared with prostacyclin- and nitroprusside-treated specimens (mean scores of 1.4 and 2.7, respectively). All nitroprusside-treated specimens demonstrated moderate to severe endothelial cell swelling. Interstitial and alveolar hemorrhage was noted in poorly preserved specimens, but there were no significant differences between groups. We conclude that prostaglandin E1 provides improved cellular preservation by decreasing the extent of endothelial cell swelling as observed on electron microscopy.

Pulmonary artery balloon counterpulsation is a promising experimental technique for treatment of right ventricular failure. However, clinical application has been limited in that the only device presently available (the large-volume intraaortic balloon) must be placed within a synthetic graft. Because a balloon with a smaller volume (which could be placed through a peripheral vein and be contained entirely within the pulmonary artery) would make the technique feasible on a wider scale, we tested an 8-mL pulmonary artery balloon placed through the femoral vein in 12 dogs. Two groups of animals were compared. One group had the pulmonary artery balloon in place but not counterpulsating; the other had the pulmonary artery balloon in place and counterpulsating. Each group was studied for 12 hours. A variety of hemodynamic parameters were measured. Effective diastolic augmentation and systolic unloading were noted in all 6 dogs that underwent counterpulsation (5.0 ± 1.1 mm Hg of diastolic augmentation and 9.5 ± 1.6 mm Hg of systolic unloading). Pulmonary function, as measured by arterial blood gas sampling and pulmonary vascular resistance, was not impaired. Examination of the heart and lungs showed no detrimental pathologic effects of pulmonary artery balloon counterpulsation. Placement of the balloon through a peripheral vein with a guidewire was easy and uncomplicated. We conclude that pulmonary artery balloon counterpulsation is safe over an extended period of 12 hours in the canine model and that diastolic augmentation and systolic unloading can be produced.

Objective Controversy exists regarding the optimal pumping method for left ventricular assist devices. The purpose of this investigation was to test the hypothesis that pulsatile left ventricular assist synchronized to the cardiac cycle provides superior left ventricular unloading and circulatory support compared with continuous-flow left ventricular assist devices at the same level of ventricular assist device flow. Methods Seven male pigs were used to evaluate left ventricular assist device function using the TORVAD synchronized pulsatile-flow pump (Windmill Cardiovascular Systems, Inc, Austin, Tex) compared with the Bio-Medicus BPX-80 continuous-flow centrifugal pump (Medtronic, Inc, Minneapolis, Minn). Experiments were carried out under general anesthesia, and animals were instrumented via a median sternotomy. Hemodynamic measurements were obtained in the control state and with left ventricular assistance using the TORVAD and BPX-80 individually. Left ventricular failure was induced with suture ligation of the mid-left anterior descending coronary artery, and hemodynamic measurements were repeated. Results During left ventricular assist device support, mean aortic pressure and total cardiac output were higher and left atrial pressure was lower with pulsatile compared with continuous flow at the same ventricular assist device flow rate. During ischemic left ventricular failure, pulsatile left ventricular support resulted in higher total cardiac output (5.58 ± 1.58 vs 5.12 ± 1.19, P 05), higher mean aortic pressure (67.8 ± 14 vs 60.2 ± 10, P 05), and lower left atrial pressure (11.5 ± 3.5 vs 13.9 ± 6.0, P 05) compared with continuous flow at the same left ventricular assist device flow rate. Conclusion Synchronized, pulsatile left ventricular assistance produces superior left ventricular unloading and circulatory support compared with continuous-flow left ventricular assist at the same flow rates.

Background Coronary artery shunting during off-pump coronary artery bypass OPCAB procedures has been addressed only infrequently. To assess the protective effect of shunting, we examined CABG patients' postoperative cardiac enzyme levels and preoperative and postoperative ejection fractions. Methods During OPCAB, we selectively shunted the left anterior descending coronary artery (LAD) to provide myocardial protection when ischemia developed. We prospectively gathered data from 408 consecutive patients who underwent OPCAB. Data on shunt status were available for 386 of these patients. A "flow-through" shunt providing perfusion to the distal LAD was used whenever ST-segment elevations greater than 2 mm occurred or when patients had hemodynamic compromise unexplained by cardiac manipulation. Ejection fraction was assessed 1 to 3 days preoperatively and again 3 to 10 days postoperatively. Creatine kinase (muscle/brain) levels were assessed postoperatively for 24 hours. Results During OPCAB, 99 patients required shunting for presumed ischemia. Thirty-day cardiac mortality was 1.4% (4 of 296 without a shunt; 0 of 90 with a shunt). In patients without a LAD shunt, the mean peak creatine kinase index was 5.3; in patients who needed a shunt, the index was 5.2. Mean ejection fraction improved from 0.536 to 0.589 in the shunted patients and from 0.53.5 to 0.586 in the nonshunted patients. Conclusions Selective shunting of the LAD during OPCAB provides effective protection against myocardial ischemia when ischemia is detected by electrocardiogram or when hypotension develops that is unexplained by cardiac manipulation.

The purpose of the present study was to test the hypothesis that adenylate cyclase activity of porcine coronary artery smooth muscle cells is sensitive to mechanical stretch. Cultured vascular smooth muscle cells were stretched at 24% maximal strain at 60 cycles/min for 30 minutes. Both basal and maximal catalytic activity of adenylate cyclase (as assessed by stimulation by 100 microM forskolin with 5 mM manganese chloride) were reduced by 30% (P less than 0.05) in membranes obtained from stretch versus unstretched cells. The magnitude of the stretch-induced reduction in Gpp(NH)p was identical over the entire time course studied (5-30 minutes). Furthermore, basal adenylate cyclase activity was inversely related to the magnitude of stretch. Thus, cyclic stretch can influence adenylate cyclase activity in coronary vascular smooth muscle cells. These data provide important information concerning potential biochemical mechanisms involved in the myogenic response of vascular smooth muscle and also suggest a potential mechanism by which the coronary circulation may adapt to chronically reduced perfusion pressure.

Background We hypothesized that not all subtypes of α- and β-adrenoreceptors undergo similar upregulation and redistribution in human myocardium after mechanical unloading with an assist device. Methods We obtained core biopsy samples of the left ventricle in 19 patients before and after removal of a Jarvik or Thoratec left ventricular assist device (LVAD) to study the effect of mechanical unloading on the distribution of α- and β-adrenoreceptors. Fresh, embedded tissue sections were incubated with receptor blockers and antibodies before the fluorescent labeling of receptors. Images were obtained by fluorescence deconvolution microscopy, and composite tissue renditions were made from the stacked images. Multiple adrenoreceptor subtypes were studied. Results We saw a reversal of myocyte hypertrophy in all patients, but the upregulation of receptors was not seen in all post-LVAD tissue samples. Furthermore, we noted receptor relocalization from an initial punctate/clumped pattern to a normal homogeneous distribution in many patients. Significant differences were seen in the distribution of β 2 - and α 1 -receptors and in α 1A subtypes. Conclusions In this study we show not only the expected reversal of myocyte hypertrophy and the increase in adrenoreceptors after ventricular unloading, but also the relocalization of specific receptor subtypes.

Although mechanical circulatory support (MCS) can improve myocardial function in patients with advanced heart failure, its effects on relative myocardial perfusion are unclear. Using positron emission tomographic imaging techniques, the authors assessed relative myocardial perfusion in patients with ischemic or idiopathic cardiomyopathy who were receiving chronic MCS with a left ventricular assist device (pulsatile HeartMate [n = 2] [Thoratec Corporation, Pleasanton, CA] or nonpulsatile Jarvik 2000 [n = 4] [Jarvik Heart, Inc., New York, NY]). Relative myocardial perfusion was compared at lower and higher levels of MCS (50 vs. 100 - 110 ejections/min for the HeartMate and 8000 vs. 12,000 rpm for the Jarvik 2000). The size and severity of perfusion defects at rest and after dipyridamole stress were measured objectively and subjectively by computer algorithms and visual inspection, respectively. Relative myocardial perfusion increased5% from baseline in only one of six patients when MCS was increased. No change in relative myocardial perfusion of5% was seen in any of the other five patients, even after subsequent dipyridamole stress positron emission tomographic imaging. These pilot study findings suggest that the decreased metabolic requirements induced by ventricular unloading correspondingly decreased blood flow requirements to physiologically inactive myocardium.

Chronic traumatic aneurysm of the thoracic aorta is an unusual occurrence. Previously, arteriography was performed on all patients seen in our institution with this entity to allow confirmation of the diagnosis and anatomic delineation for operation. A case of chronic traumatic aneurysm of the distal descending aorta discovered on a routine chest roentgenogram and evaluated with chest computed tomographic scanning with three-dimensional reconstruction is presented. It is our belief that not all thoracic aneurysms require arteriography, and improved methods of computed tomographic scanning allow adequate diagnosis and anatomic delineation with decreased morbidity and cost.

Background Long-term left ventricular assist device (LVAD) support diminishes flow through the native aortic valve and decreases valve motion. This may cause aortic valve commissural fusion. The clinical importance of such fusion is not well understood. Methods Thirty-three consecutive patients receiving long-term LVAD support were followed up until transplantation or death. In each case, the native aortic valve was examined pathologically for commissural fusion. Pathology findings were correlated with hemodynamic performance as assessed by both LVAD pump flow and echocardiography. Results Seventeen of the 33 patients had some degree of native aortic valve commissural fusion. Four patients had fusion at 2 commissures; of these, 2 had clinically significant native valve aortic insufficiency (2+ or greater), and 1 exhibited trace insufficiency of the native aortic valve. Thirteen patients had fusion at only 1 aortic commissure; of these, 2 had clinically significant aortic insufficiency (2+ or greater), and 3 had trace or mild (1+) insufficiency of native aortic valve. Two of the 4 patients with fusion at 2 commissures required increased LVAD support of >3 liters/min/cm 2 . No patient with fusion of only 1 commissure required increased LVAD support. Three patients with no commissural fusion of the aortic valve required increased LVAD support secondary to sepsis. Conclusions Commissural fusion of the native aortic valve occurs in a significant number of patients receiving long-term LVAD support and can necessitate increased levels of LVAD support. Recognition of this phenomenon may allow development of strategies to minimize commissural fusion and extend LVAD pump life.

Continuous flow pumps are increasingly used to treat severe heart failure. These pumps alter flow physiology by lowering pulsatility in the arterial circulation. In patients with peripheral stenosis, continuous flow pumps may lead to thrombosis of peripheral vessels, possibly predisposing to vascular thrombosis in areas of non-flow-limiting stenosis. The authors performed a computerized flow modeling simulation to analyze the effects of altered hemodynamics in a stenotic area. Drawing on previous clinical experience, we modeled a stenotic area in the common carotid artery. Computerized flow modeling revealed blood stagnation zones with low shear stress and velocity adjacent to the stenotic area during nonpulsatile flow. Such stagnation was not present during pulsatile flow. These results indicate a mechanism by which altered physiologic flow may accelerate occlusion of arterial conduits in patients with preexisting stenosis. This finding may be important for patients with continuous flow devices who have peripheral vascular disease; therefore, further study is warranted.

New surgical procedures, imaging modalities, and medical devices have improved therapy for many patients and made treatment possible for others who have had few options in the past. In February 2004, the National Heart, Lung, and Blood Institute’s (NHLBI) Advisory Council proposed that the institute evaluate the status and future directions in cardiac surgery. In response to this recommendation, the NHLBI convened a working group of cardiac surgeons on May 7 and 8, 2004, to assess the state of cardiac surgery research, identify critical gaps in current knowledge, determine areas of opportunity, and obtain specific recommendations for future research activities. The working group discussed surgical revascularization, novel surgical approaches, valvular research directions, biotechnology and cell-based therapy, heart failure, imaging modalities, and barriers to clinical research and presents its recommendations here.

Background To assess optimal timing for coronary artery bypass graft surgery (CABG) after an acute myocardial infarction (AMI), all patients undergoing CABG without associated procedures at our institution from January 1, 1991, to July 30, 1992, were reviewed. Patients were divided into three groups based on time from infarct to revascularization. The control group consisted of patients operated on for angina refractory to medical management. Relative risks (incident infarction group divided by incident control group) were established for need of vasopressors, new balloon to separate from bypass, perioperative myocardial infarction, and hospital mortality. Methods and Results One hundred sixteen patients underwent CABG within 6 weeks of infarction. In the experimental group, 58 patients underwent CABG for non–Q-wave infarction, and 58 patients underwent CABG for Q-wave infarction. In the control group, 255 patients underwent surgery for angina without infarction. Patients were analyzed by group relative to the time between infarction and CABG. Patients were analyzed between infarction and CABG and assigned to one of three groups. Group 1 patients were revascularized within 48 hours; group 2, between 3 and 5 days; and group 3, after 5 days. Significance was determined by Fisher’s exact or Mantel-Haenszel χ 2 test where appropriate. Multivariate analysis was performed on statistics that were significant. All patients within all groups after Q-wave or non–Q-wave myocardial infarction had a significantly higher risk of needing an intra-aortic balloon pump and vasopressors to be weaned from bypass and a greater incidence of perioperative MI compared with control patients. Surgical mortality is highest immediately after Q-wave infarctions. Conclusions Patients with non–Q-wave infarction may undergo CABG relatively safely at any time. Acceptable timing for CABG after Q-wave infarction is after 48 hours.