Right ventricle-sparing left ventricular resection and replacement with a continuous-flow rotary blood pump: an in vivo experiment

Despite recent advances in left ventricular assist device and total artificial heart technologies, these devices are still so large that they pose a significant problem in small patients with refractory heart failure. Excising the left ventricle while preserving the right ventricle--and then replacing the left ventricle with a mechanical pump--has been proposed as an alternative approach to this problem. We conducted a pilot study to evaluate possible surgical techniques and the hemodynamic effects of right ventricle-sparing left ventricular resection and replacement with a continuous-flow rotary blood pump in a healthy bovine model.

Levosimendan vs. dobutamine: outcomes for acute heart failure patients on beta-blockers in SURVIVE

AIMS

Many chronic heart failure (CHF) patients take beta-blockers. When such patients are hospitalized for decompensation, it remains unclear how ongoing beta-blocker treatment will affect outcomes of acute inotrope therapy. We aimed to assess outcomes of SURVIVE patients who were on beta-blocker therapy before receiving a single intravenous infusion of levosimendan or dobutamine.

METHODS AND RESULTS

Cox proportional hazard regression revealed all-cause mortality benefits of levosimendan treatment over dobutamine when the SURVIVE population was stratified according to baseline presence/absence of CHF history and use/non-use of beta-blocker treatment at baseline. All-cause mortality was lower in the CHF/levosimendan group than in the CHF/dobutamine group, showing treatment differences by hazard ratio (HR) at days 5 (3.4 vs. 5.8%; HR, 0.58, CI 0.33-1.01, P = 0.05) and 14 (7.0 vs. 10.3%; HR, 0.67, CI 0.45-0.99, P = 0.045). For patients who used beta-blockers (n = 669), mortality was significantly lower for levosimendan than dobutamine at day 5 (1.5 vs. 5.1% deaths; HR, 0.29; CI 0.11-0.78, P = 0.01).

CONCLUSION

Levosimendan may be better than dobutamine for treating patients with a history of CHF or those on beta-blocker therapy when they are hospitalized with acute decompensations. These findings are preliminary but important for planning future studies.

PleurX catheter for the management of refractory pleural effusions in congestive heart failure

Pleural effusions that are caused by congestive heart failure and refractory to medical management are rare, and the options for treating them are few and sometimes ineffective. We report here our experience, over a 2-year period, with a novel device, the Denver Biomedical PleurX pleural catheter, in treating a series of 5 patients who had chronic, refractory, heart-failure-associated pleural effusions. The PleurX catheter is a small-bore chest tube designed to remain in place for prolonged periods, through which drainage of pleural fluid can be performed easily on a daily or less frequent outpatient basis. Placement of the catheter, in our series, was associated with no complications. In all patients, the catheter effectively drained the pleural space initially, thereby controlling the effusions and alleviating New York Heart Association functional class IV symptoms. The catheters remained in place for a period of 1 to 15 months. In 2 of the patients, the catheter was associated with no complications during the time that it remained in place. One of these patients had the catheter removed at heart transplantation, and 1 retained the catheter until death from underlying heart disease. For 1 patient, the catheter resulted in a partially loculated pleural space, and it was removed. In 2 patients, after prolonged use, it was associated with empyema, for which it was removed. We conclude that the PleurX catheter can effectively control refractory congestive-heart-failure-associated pleural effusions temporarily, but that its prolonged use can cause significant complications, most importantly empyema.

ALCAPA with the ectopic orifice at the non-facing sinus: successful anatomic repair by creation of an autologous extrapulmonary tunnel

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital defect. This anomaly leads to a coronary hypoperfusion phenomenon and to substantial left ventricular dysfunction caused by abnormal perfusion of the left ventricle. The optimal surgical management of such cases is not clearly established. Here, we report the successful anatomic repair of ALCAPA arising from the non-facing sinus of Valsalva of the pulmonary artery in a 5-kg patient. In order to perform the repair, we created an autologous extrapulmonary tunnel (from a pulmonary artery flap and autologous pericardium), which we implanted into the ascending aorta. Because of post-cardiotomy heart failure, we implanted an extracorporeal membrane oxygenation device during the same procedure. After recovery of the failing heart, the device was easily ex-planted, and the patient was discharged from the hospital on postoperative day 30.

Effects of carvedilol on plasma levels of pro-inflammatory cytokines in patients with ischemic and nonischemic dilated cardiomyopathy

We prospectively investigated the effects of adding carvedilol to the standard treatment of ischemic and nonischemic dilated cardiomyopathy (DCM), by measuring the plasma levels of pro-inflammatory cytokines. Sixty patients with DCM (35 ischemic and 25 nonischemic) were divided into 2 subgroups: patients on standard therapy alone (digoxin, angiotensin-converting enzyme inhibitors, and diuretics) and patients on standard therapy plus carvedilol. Study participants' serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), and interleukin-6 (IL-6) were measured at the beginning and again at the end of the study. Left ventricular ejection fraction and left ventricular diastolic function were evaluated by means of radionuclide ventriculography. In ischemic patients on carvedilol, levels of IL-6 and TNF-alpha dropped significantly (P= 0.028 and P=0.034, respectively). In ischemic patients on standard treatment, plasma IL-2 levels were elevated after treatment (P=0.047). No significant differences occurred in IL-6 levels, while TNF-alpha levels were elevated (P=0.008). In nonischemic patients on carvedilol, IL-6 and TNF-alpha levels dropped significantly (P=0.018 and P=0.004, respectively). The left ventricular ejection fraction increased significantly (P=0.006). In nonischemic patients on standard treatment, no significant change occurred in any value. Carvedilol suppressed the plasma levels of TNF-alpha and IL-6 in both ischemic and nonischemic patients. The carvedilol effect was more pronounced in patients with nonischemic dilated cardiomyopathy than in those with ischemic disease.

A synopsis of research in cardiac apoptosis and its application to congestive heart failure

Cardiac apoptosis diminishes the contractile mass, which leads to heart failure. Apoptosis of cardiac non-myocytes also contributes to maladaptive remodeling and the transition to decompensated congestive heart failure. New antiapoptotic interventions and medications will be available within the next decade. The aim of this study is to provide a critical synopsis of research projects on cardiocyte apoptosis that have implications for current and future practice and to identify methods to prevent or attenuate apoptosis in patients who have poor ventricular function. A retrospective literature review reveals a great many important publications. However, very few investigators discuss the clinical ramifications of cardiocyte apoptosis, nor do they address the clinician who sees poor ventricular contractility daily. Most studies are still investigational and involve antiapoptotic agents such as broad-spectrum caspase inhibitors, antioxidants, calcium channel blockers, insulin-like growth-factor 1, and poly(adenosine diphosphate ribose) synthetase inhibitors. some options have already been incorporated into the clinical practices of cardiologists and cardiac surgeons: repairing or replacing diseased or damaged valves before ventricular function deteriorates; reducing afterload with medication or intra-aortic balloon pulsation in patients who display acute increases in afterload; decreasing catecholamine-induced cardiotoxicity in hemodynamically compromised patients, by using beta-blockers and phosphodiesterase inhibitors; and inserting intra-aortic balloon pumps or ventricular assist devices early in cases of failing myocardium. Coronary revascularization early in myocardial infarction is effective antiapoptotic therapy. Other therapeutic targets are cardiopulmonary bypass and aortic cross-clamping, both of which require reductions in associated myocardial apoptosis.

BiDil: assessing a race-based pharmaceutical

Isosorbide and hydralazine in a fixed-dose combination (BiDil) has provoked controversy as the first drug approved by the Food and Drug Administration marketed for a single racial-ethnic group, African Americans, in the treatment of congestive heart failure. Family physicians will be better prepared to counsel their patients about this new drug if they understand a number of background issues. The scientific research leading to BiDil's approval tested the drug only in African American populations, apparently for commercial reasons, so the drug's efficacy in other populations is unknown. Race as a biological-medical construct is increasingly controversial; BiDil offers a good example of how sociocultural factors in disease causation may be overlooked as a result of an overly simplistic assumption of a racial and hence presumed genetic difference. Past discrimination and present disparities in health care involving African American patients are serious concerns, and we must welcome a treatment that promises to benefit a previously underserved group; yet the negative aspects of BiDil and the process that led to its discovery and marketing set an unfortunate precedent. Primary care physicians should be aware of possible generic equivalents that will affect the availability of this drug for low-income or uninsured patients.

Left main coronary artery stenosis: factors predicting cardiac events in patients awaiting coronary surgery

Although most patients with left main coronary artery stenosis undergo urgent coronary artery bypass grafting, limited information is available regarding the risk factors that might lead to cardiac events between angiographic diagnosis and surgery. We retrospectively reviewed 1,731 cases of coronary artery bypass grafting at our institution, 97 of which were performed in patients with significant (> or = 50%) left main coronary artery stenosis. These patients were placed in 1 of 2 groups: eventful waiting or uneventful waiting. We analyzed multiple preoperative variables, and the incidence of serious cardiac events (death, myocardial infarction, unstable angina, left ventricular failure, and life-threatening ventricular arrhythmias) during the waiting period between angiography and surgery Four patients (4.1%) experienced serious cardiac events while awaiting surgery (1 had non-ST-elevation myocardial infarction; 3 had life-threatening ventricular arrhythmias); none died. All the events occurred more than 24 hours after cardiac catheterization. Of the preoperative variables analyzed (acute coronary syndrome, age, history of diabetes, hypertension, hyperlipidemia, smoking, renal failure, severity of left main stenosis, right coronary artery involvement, ejection fraction, and use of intra-aortic balloon pump), only acute coronary syndrome predicted the incidence of preoperative cardiac events (P=0.001). The occurrence of severe cardiac events while patients await coronary artery bypass grafting is rare. Carefully selected patients with severe left main coronary artery stenosis can safely await surgery. Concomitant acute coronary syndrome and severe left main coronary artery stenosis indicate a high risk for cardiac events. Therefore, in patients with these conditions, emergency coronary artery bypass may be preferable.

Successful ventricular remodeling with coronary artery bypass grafting and mitral valve repair in a patient with severe heart failure

Left ventricular remodeling is becoming a frequent treatment for severe heart failure, but its use in combination with other surgical techniques is controversial. We report a case in which left ventricular remodeling was combined with coronary artery bypass grafting and mitral valve repair to treat a patient with severely depressed ejection fraction, mitral insufficiency, coronary artery disease, and a recent history of myocardial infarction. Cardiac function improved after the combined treatment. This case suggests that left ventricular remodeling can be used safely and effectively in conjunction with other surgical techniques.

Biventricular pacing for heart failure patients on inotropic support: a review of 38 consecutive cases

Biventricular pacing (BiV) has documented benefit in New York Heart Association functional class III patients. Whether BiV offers benefit to class IV patients on inotropic therapy is unclear. Retrospective review was performed on 38 consecutive heart failure patients who received BiV while on inotropic support or within 30 days of inotropic administration; the mean age was 63 +/- 13 yrs; 9 were women. Fourteen who received inotropic agents did so in conjunction with coronary artery bypass grafting, or valve or infarct exclusion surgery. Twenty-three patients received inotropic therapy only before BiV Nine other patients received inotropic therapy before BiV and at another point (5 at implant and 4 after BiV); 6 were on inotropic support only at implant. Mean follow-up was 1.2 +/- 0.9 years. There were 14 deaths. Survival estimates at 6 months, 1 year, and 2 years were 74%, 71%, and 61%, respectively. When patients on inotropic therapy before BiV (n=32) were compared with patients never on such therapy before BiV (n=6), there was a survival difference (P <0.0001); all 6 patients not on inotropic therapy before BiV died within the first 2 years. Estimated 6-month and 1-year survival for those on inotropic support before BiV was 84 % and 81 %, compared with 23% and 23% for the other group. Patients who required inotropic agents only before BiV fared better than those requiring inotropic support at other times. Although the patients in this survey were a very high-risk group, a small subset was weaned and had stable short-term survival.

Thirty-five years of mechanical circulatory support at the Texas Heart Institute: an updated overview

Since the 1960s, the Texas Heart Institute has been intimately involved in the development of mechanical circulatory support devices (for example, ventricular assist devices, aortic counterpulsation pumps, and total artificial hearts) for both short- and long-term use. Here, we review the varied clinical experience with these technologies at the Texas Heart Institute over the last 35 years.

Pulmonary microthrombi during left ventricular assist device implantation

Critically ill heart failure patients undergoing left ventricular assist device implantation have alterations in their coagulation profiles; as a result, hemorrhagic complications during the postoperative period are the most common and serious problems during device support of these patients. The use of aprotinin therapy is generally accepted for reducing bleeding after coronary artery bypass grafting procedures, heart transplantation, and insertion of a left ventricular assist device. We describe the case of a patient who had a suprasystemic increase in pulmonary artery pressure, caused by thromboembolic occlusion of the pulmonary arterioles after urgent implantation of a left ventricular assist device. The complications developed after the patient was weaned from cardiopulmonary bypass and heparinization was reversed with protamine. Although the thrombosis was successfully reversed with intraoperative administration of tissue plasminogen activator directly to the pulmonary artery, the patient died of massive hemorrhage 6 hours later. To our knowledge, the direct application of tissue plasminogen activator into the pulmonary artery in such a catastrophic situation has not been used elsewhere.

Coronary artery bypass grafting alone for advanced ischemic left ventricular dysfunction with significant mitral regurgitation: early and midterm outcomes in a small series

In 31 consecutive patients with ischemic left ventricular dysfunction and mitral regurgitation ranging from 2/4 to 3/4 (mean, 2.87 +/- 0.34), we performed coronary bypass grafting alone and assessed early and midterm outcomes. Our patients' mean preoperative New York Heart Association functional class was 3.64 +/- 0.48, and their mean left ventricular ejection fraction was 0.25 +/- 0.05. Preoperative thallium imaging revealed that all patients had at minimum a partially reversible defect in the anterior wall. All patients survived the operation. Hospital length of stay ranged from 5 to 21 days (mean, 8.35 +/- 4.07 days), and mean length of follow-up was 21.35 +/- 13.24 months. Postoperatively, patients' functional classification improved to a mean of 1.32 +/- 0.6; left ventricular ejection fraction improved to a mean of 0.43 +/- 0.09; and severity of mitral regurgitation decreased to a mean of 1.35 +/- 0.96. Statistical analysis showed that all improvements were significant. Five late cardiac deaths occurred. Preoperative variables showed no correlation with late death. However, postoperative left ventricular ejection fraction and mitral regurgitation did correlate with late death, which suggests that the reversibility of damaged ischemic myocardium plays an important role after revascularization. This study supports the concept that ischemic mitral regurgitation might well improve after myocardial revascularization regardless of its severity; therefore, it should not be corrected at the primary operation, except in patients with organic valvular changes.

Congenital absence of anterior pericardium at left ventricular assist device implantation

We report a case of congenital absence of the anterior pericardium in a 41-year-old man who was undergoing implantation of a left ventricular assist device for treatment of congestive heart failure.

Intravenous milrinone in treatment of advanced congestive heart failure

Phosphodiesterase inhibitors such as milrinone can relieve symptoms and improve hemodynamics in patients with advanced congestive heart failure. We retrospectively evaluated the hemodynamic and clinical outcomes of long-term combination therapy with intravenous milrinone and oral beta-blockers in 65 patients with severe congestive heart failure (New York Heart Association class IV function and ejection fraction <25%) refractory to oral medical therapy. Fifty-one patients successfully began beta-blocker therapy while on intravenous milrinone. Oral medical therapy was maximized when possible. The mean duration of milrinone treatment in this combination-treatment group was 269 days (range, 14-1,026 days). Functional class improved from IV to II-III with milrinone therapy. Twenty-four such patients tolerated beta-blocker up-titration and were successfully weaned from milrinone. Sixteen patients (31%) died while receiving combination therapy; one died of sudden cardiac death (on treatment day 116); the other 15 died of progressive heart failure or other complications. Hospital admissions during the previous 6 months and admissions within 6 months after milrinone initiation stayed the same. Meanwhile, the total number of hospital days decreased from 450 to 380 (a 15.6% reduction), and the mean length of stay decreased by 1.4 days (a 14.7% reduction). We conclude that 1) milrinone plus beta-blocker combination therapy is an effective treatment for heart failure even with beta-blocker up-titration, 2) weaning from milrinone may be possible once medications are maximized, 3) patients' functional status improves on the combination regimen, and 4) treatment-related sudden death is relatively infrequent during the combination regimen.

Effects of carvedilol therapy on QT-interval dispersion in congestive heart failure: is there a difference in the elderly?

In cases of chronic congestive heart failure, QT-interval dispersion is a strong predictor of death. Carvedilol therapy appears to decrease QT-interval dispersion. We investigated whether carvedilol reduces QT-interval dispersion in congestive heart failure and whether this pharmaceutical agent has additional effects on elderly patients. Seventy-seven ambulatory patients who had chronic congestive heart failure were evaluated for hypertension, diabetes mellitus, smoking, alcohol abuse, concomitant medications, and QT-interval dispersion. Carvedilol therapy was then initiated. Six months later, we re-evaluated the same variables, as well as morbidity and mortality rates, and number of hospitalizations. The patients were divided into 2 groups: Group I, aged < 65 years (n = 42); and Group II, aged > or = 65 years (n = 35). Statistics were analyzed with the Student's t-test chi2 test, and Cox regression model. At 6 months, both groups showed significantly decreased QT-interval dispersion values compared with baseline values (76.9 +/- 29.3 vs 104.3 +/- 41.5 ms, respectively; P < 0.0001). An elevated QT-interval dispersion value at baseline increased morbidity (P = 0.041) but not hospitalization (P > 0.05). Group II had a smaller reduction in QT-interval dispersion than did Group I (24.41 +/- 29.36 and 30.98 +/- 32.70 ms, respectively), but this difference was not significant. We conclude that in ambulatory patients with chronic congestive heart failure, long-term carvedilol therapy significantly decreases QT-interval dispersion, and this effect is uniformly distributed between patients aged < 65 years and those aged 265 years.

Complete atrioventricular canal defect: surgical considerations

Complete atrioventricular canal defect is a serious and complex cardiac anomaly that is frequently associated with other congenital cardiac defects. Its natural course is ultimately fatal; 80% of children born with this defect will die within 2 years. Long-term medical therapy for complete atrioventricular canal defect is ineffective; therefore, either palliative or curative surgery is required. The risk of corrective surgery for this defect in infancy has steadily decreased because of improvements in surgical techniques, anesthesia, and postoperative management. This report describes our current surgical technique for primary corrective repair of complete atrioventricular canal defect, with a review of recent results of this procedure in 34 patients.

Successful treatment of acute postoperative right heart failure with low-dose prostaglandin e(1) and assisted circulation

Immediately after undergoing emergency mitral valve replacement, a 60-year-old woman suffered acute postoperative right heart failure and could not be weaned from cardiopulmonary bypass, despite treatment with multiple drugs. Circulatory assistance was instituted by means of femoro-femoral bypass with a roller pump and a hollow-fiber oxygenator; inotropic drugs and drugs aimed at reducing pulmonary vascular resistance (nitroprusside, moxaverine, and isoproterenol) were also given. The patient's systolic pulmonary pressure underwent a progressive decrease, but her systolic systemic pressure remained below 60 mmHg until 8.5 hours after aortic clamp release, when we were able to begin an infusion of prostaglandin E(1), a drug not readily available in our hospital. Fifteen minutes after the infusion was started, at 5 ng/kg/min, the patient's systolic systemic pressure reached 85 mmHg and her systolic pulmonary pressure decreased to 55 mmHg. During the next 2 hours, epinephrine treatment was discontinued, and the assisted circulatory flow was reduced to 0.5 L/min/m(2), while the PGE(1) infusion was increased to 10 ng/kg/min. Assisted circulation was soon discontinued, and the patient's hemodynamic condition remained stable.

Use of a left ventricular assist device as a bridge to transplantation in a pediatric patient

Despite many advances in heart transplantation and in mechanical circulatory support, the benefits of staged cardiac transplantation have not been extended to the pediatric transplant recipient, chiefly because implantable circulatory assist devices are still too large. Extracorporeal devices, however, can overcome this impediment. Here we report the 1st case, to our knowledge, in which an extracorporeal left ventricular assist device has been used in a child to support circulation prior to cardiac transplantation. The patient was a 9-year-old boy in New York Heart Association functional class IV, with congestive heart failure as a result of idiopathic biventricular cardiomegaly. In mid-May of 1987, while awaiting a suitable donor, he suffered severe oliguria after an episode of circulatory arrest. Therefore we decided to maintain his circulation-and consequently his peripheral organ function-with an extracorporeal left ventricular assist device. After establishing cardiopulmonary bypass under normothermia and without cardiac arrest, we established flow from the left ventricle through a 36-Fr wire-reinforced straight cannula to a Biomedicus BP-80 centrifugal force pump, with return to the proximal ascending aorta through a 28-Fr wire-reinforced straight cannula. The patient's hemodynamic course under subsequent mechanical circulatory support was remarkably stable, with controllable systemic hypertension and no evidence of hemolysis. Although cardiac activity was minimal and systemic blood flow nonpulsatile, the patient's renal, pulmonary, and hepatic functions improved, and his peripheral circulation was well preserved. After 12 hours of support, a donor heart became available, and a routine orthotopic cardiac transplant was performed. Upon removal, the left ventricular assist device showed a small amount of thrombus formation. The patient's postoperative recovery has been easily manageable, and 20 months after transplant he enjoys unrestricted physical activity. We conclude that an extracorporeal left ventricular assist device can be used as a bridge to cardiac transplantation in children. Moreover, this application of a continuous force centrifugal pump without adverse effect encourages the conclusion that long-term maintenance of terminal heart disease patients might be possible through development of small, implantable pumps with the potential of lower power requirements and reduced thrombogenesis.

Diagnosis and management of infective endocarditis

Images

Heterotopic heart transplantation: current indications for the procedure, with results in 10 patients

From January 1986 to September 1987, we performed 27 orthotopic and 10 heterotopic cardiac transplantations at our institution. Of the 10 heterotopic transplantation recipients, 9 were men; ages ranged from 36 to 65 years; and indications for transplantation were ischemic cardiomyopathy in 8 patients and dilatative cardiomyopathy in 2 patients. Five of the 10 heterotopic transplantation recipients received donor hearts under emergency conditions, when no hearts of suitable size for orthotopic transplantation were available. In 3 of the 10 heterotopic procedures, we performed pure left ventricular (rather than biventricular) bypass in patients with chronic conditions requiring only aneurysmectomy, or aneurysmectomy in combination with an aortocoronary graft. During postoperative hospitalization, the following complications occurred in the 10 heterotopic-transplantation recipients: 10 infectious episodes in 6 patients; 1 episode of severe graft rejection; and 1 episode of severe gastrointestinal bleeding. All these complications were overcome, and no patient in the heterotopic-transplantation group died. Fifteen months postoperatively, one male in the group lost his graft, but his own heart had by then recovered function, despite dilatative cardiomyopathy. More commonly, late investigation (6 months or longer after transplantation) has yielded ambiguous overall evaluations of pump performance of the recipients' native hearts, showing slight improvement in some instances and further deterioration in others. We conclude that heterotopic heart transplantation is a life-saving procedure in urgent cases when only small donor hearts are available, and that it offers a good chance of hemodynamic and functional improvement not only in emergency cases, but also in cases of chronic cardiomyopathy when there is salvageable myocardium.

The pathogenesis and prognosis of end-stage heart disease

The final outcome of many forms of heart disease is congestive heart failure (CHF), a condition in which the heart can no longer pump enough blood to fulfill the body's metabolic requirements. Systolic heart failure is characterized by an impairment of myocardial contractility, whereas diastolic heart failure results from the left ventricle's inability to distend normally. The general features of CHF include pressure or volume overload, muscle loss, decreased myocardial contractility, or restrictive filling. Treatment is palliative, and 50% of the patients with CHF can be expected to die within 5 years; the mortality is much higher in those with coronary disease or limiting symptoms. The following signs are associated with a particularly poor prognosis: age > 55 years, cardiomegaly, a cardiac index of < 3, a left-ventricular end-diastolic pressure of > 20 mmHg, an ejection fraction of < 30%, a thin ventricular wall, dyspnea, and evidence of atrial fibrillation or ventricular tachycardia. Because of their high mortality, many of these patients eventually become candidates for cardiac transplantation.

Pharmacologic therapy for patients with congestive cardiomyopathy

Treatment in congestive heart failure is directed at improving cardiac output and decreasing preload and afterload without significantly increasing the oxygen requirements of the heart. This paper reviews the current approach to heart failure with inotropic and vasodilator drugs in patients with heart failure.