Abstract T P347: Metabolomic Analysis of PFO-Related Stroke Shows Immediate and Persistent Decrease of Homocysteine Post PFO Closure

Background: PFO, an independent stroke risk factor, enables direct mixing of venous and arterial circulation. As we have found previously, PFO serves not only as a conduit for venous clots, but also enables harmful factors such as serotonin (5HT) to avoid pulmonary filtration to remain within circulation at elevated levels, potentially contributing to a prothrombotic state. We hypothesize that in addition to 5HT, other factors may also be involved. In the context of endovascular PFO closure, a bedside model to understand PFO circulatory signaling, we performed a full metabolomic profile of mediators that may respond to PFO closure.

Method: Non-migraine stroke patients were recruited in accordance with IRB approval, plasma was sampled from left and right atria pre and post closure and also from venous blood 3 months post PFO closure. A discovery metabolite screening was performed in 14 patients who underwent PFO closure, and analysis was performed using one-way ANOVA.

Result: After stringent data filtering (537 metabolites, one-way ANOVA, p-value <0.01), we identified significant changes in a panel of small molecules after PFO closure - the most prominent change being in homocysteine (HCY). While relative HCY levels (expressed as peak area) in the left atrium (LA) and right atrium (RA) were comparable pre-closure (pre-LA: 5.61 ± 0.09; pre-RA: 5.30 ± 0.48), HCY immediately decreased in LA post PFO closure (post-LA: 4.56 ± 0.04) and HCY level remained low in peripheral venous blood at 3-month follow-up (4.57 ± 0.06; p = 0.0036).

Conclusion: We found PFO closure to lower HYC immediately in left atrial (arterial) blood, and this effect persists in peripheral venous circulation at 3 months post procedure. Since high level of HYC is independently associated with stroke and heart disease, our results suggest that mechanical PFO repair may improve circulatory profile of PFO stroke patients. Studies in a larger patient cohort and validation of other important metabolites are ongoing.

Abstract TP430: Plasma Proteomic Changes Persist in Long Term Follow-up of Patent Foramen Ovale Related Stroke Patients after PFO Closure

Introduction: Paradoxical embolism from patent foramen ovale (PFO), a heterogeneous multi-organ condition involving brain, lung, heart and blood, lacks consensus for treatment options due to variability among individual patients. Clinical proteomic approaches may be promising for such complex diseases, where the disease process can be monitored in clinically accessible fluid such as blood. Here, we apply a pharmaco-proteomic approach to study PFO endovascular closure, an intervention that requires better risk stratification and monitoring of therapeutic efficacy to individualize treatment. Previously, we found that plasma small molecule signals such as serotonin, TSP-1 and microparticles -- which may avoid pulmonary filtration via PFO -- decrease immediately in the systemic circulation after effective PFO closure. Now we study the long-term effect of PFO endovascular closure.

Methods/Results: To reduce confounders in an inherently complex system, the most robust clinical proteomic comparisons are those of profiles taken over time from the same individual. Accordingly, in consecutively recruited patients who underwent PFO closure (n=37), we analyze venous blood obtained prior to closure and in long-term followup (1-3 yrs) post closure. None of the subjects experienced recurrent TIA or strokes. More than 1 year post closure, plasma protein profiles -- in addition to the persistent decrease in small molecules such as serotonin -- continue to show a statistically significant (p<0.05) decrease of coagulation markers such as fibrinogen, fibrinogen fragments, D-dimer and others. Moreover, markers of inflammatory changes such as hsCRP, apolipoproteins and various immunoglobulins also remain decreased.

Conclusion: A pharmaco-proteomic approach is clinically feasible and may help to monitor therapeutic efficacy, improve patient selection, and ensure more precise clinical phenotyping for clinical trials in PFO-related stroke. More than 1 year post PFO closure, relevant inflammatory and coagulation factors remain lowered after adjusting for other confounders such as medication changes. Further studies are needed to explore the utility of proteomic profiling to help individualize treatment in PFO-related strokes.

Length of stay and procedure utilization are the major determinants of hospital charges for heart failure

BACKGROUND

Most of the 10 billion dollars spent annually on heart failure (HF) management in this country is attributed to hospital charges. There are widespread efforts to decrease the costs of treating this disorder, both by preventing hospital admissions and reducing lengths of stay (LOS).

HYPOTHESIS

The objective of this study was to identify the major determinants of hospital charges for an acute hospitalization for HF among a large, diverse group of patients.

METHODS

Administrative information on all 1995 New York State hospital discharges assigned ICD-9-CM codes indicative of HF in the principal diagnosis position were obtained. Bivariate and multivariate statistical analyses were utilized to determine those patient- and hospital-specific characteristics which had the greatest influence on hospital charges.

RESULTS

In all, 43,157 patients were identified. Mean hospital charges were $11,507+/-15,995 and mean hospital LOS was 9.6+/-14.5 days. With multivariate analyses, the most significant independent predictors of higher hospital charges were longer LOS, admission to a teaching hospital, treatment in an intensive care unit, and the utilization of cardiac surgery, permanent pacemakers, and mechanical ventilation. Age, gender, race, comorbidity score, and medical insurance, as well as treatment by a cardiologist and death during the index hospitalization were not among the most significant predictors.

CONCLUSIONS

We conclude that LOS and procedure utilization are the major determinants of hospital charges for an acute episode of inpatient HF care. Reducing LOS and other initiatives to restructure hospital-based HF care may reduce total health care costs for HF.

Myocardial stunning in hyperthyroidism

The cases of two patients with hyperthyroidism and acute left ventricular (LV) dysfunction with segmental wall motion abnormalities resulting in heart failure are reported. Both had electrocardiographic changes mimicking ischemic coronary artery disease. Treatment with antithyroid medications, beta blockers, and angiotensin-converting enzyme inhibitors rapidly restored LV function. The rapid reversibility suggests a role for myocardial stunning, an important entity to recognize in hyperthyroidism since this form of LV dysfunction can be reversed with appropriate treatment.

Apoptosis in heart failure: a tale of heightened expectations, unfulfilled promises and broken hearts em leader

Although apoptosis contributes significantly to remodeling of the fetal heart during evolution of cardiac chambers and correct routing of the great vessels, it has been believed that apoptosis does not occur in terminally differentiated adult cardiac muscle cells. However, apoptosis has recently been demonstrated in animal models of heart failure as well as in explanted hearts from patients with end-stage heart failure undergoing cardiac transplantation. Ventricular dilatation and neurohormonal activation, the hall-marks of heart failure, lead to upregulation of transcription factors, induce muscle cell hypertrophy and prepare cells for entry into the cell-division cycle. However, since terminally differentiated myocytes cannot divide, they die by apoptosis. It has been proposed that low-grade apoptosis in failing heart may be responsible for inexorable decline in left ventricular function. Better understanding of the molecular and cellular basis of apoptosis in the failing myocardium may lead to development of strategies aimed at preventing progressive myocyte loss and deterioration in left ventricular function.

Quality of care and hospital readmission in congestive heart failure: an explicit review process

BACKGROUND

The effect of hospital quality of care on hospital readmission for patients with congestive heart failure (CHF) has not been widely studied.

METHODS AND RESULTS

We examined the effects of clinical factors, hospital quality of care, and cardiologist involvement on 3-month readmission rates in patients with CHF by using a 125-item explicit review instrument comprising 3 major domains: admission work-up, evaluation and treatment, and readiness for discharge. During the 3 months after discharge, 59 (30%) of 205 patients were readmitted for CHF. The average evaluation and treatment score was lower for readmitted patients (63% v 58%; P = .04). The specific quality criteria differing between patients readmitted or not readmitted included the performance of any diagnostic evaluation, performance of echocardiography in patients with unknown ejection fraction or suspected valvular disease, and therapy with an angiotensin-converting enzyme inhibitor on discharge. Patients with <or=50% of the evaluation and treatment criteria met were more likely to be readmitted (odds ratio, 2.5; 95% confidence interval, 1.1-5.3; P = .02). In a multivariate model including both clinical characteristics and quality criteria, a low evaluation and treatment score was an independent predictor of readmission. Cardiologist involvement was correlated with higher quality-of-care scores in the admission work-up (4.8% higher; P < .01) and evaluation and treatment (8.6% higher; P < .0001).

CONCLUSIONS

Hospital quality of care for patients with CHF is independently associated with 3-month readmission rates, and cardiologist involvement during hospitalization is associated with overall quality of care.

Underuse of invasive procedures among Medicaid patients with acute myocardial infarction

OBJECTIVES

The purpose of this study was to determine whether underuse of cardiac procedures among Medicaid patients with acute myocardial infarction is explained by or is independent of fundamental differences in age, race, or sex distribution; income, coexistent illness; or location of care.

METHODS

Administrative data from 226 hospitals in New York were examined for 11,579 individuals hospitalized with a primary diagnosis of acute myocardial infarction. Use of various cardiac procedures was compared among Medicaid patients and patients with other forms of insurance.

RESULTS

Medicaid patients were older, were more frequently African American and female, and had lower median household incomes. They also had a higher prevalence of hypertension, diabetes, lung disease, renal disease, and peripheral vascular disease. After adjustment for these and other factors, Medicaid patients were less likely to undergo cardiac catheterization, percutaneous transluminal coronary angioplasty, and any revascularization procedure.

CONCLUSIONS

Factors other than age, race, sex, income, coexistent illness, and location of care account for lower use of invasive procedures among Medicaid patients. The influence of Medicaid insurance on medical practice and process of care deserves investigation.

Socioeconomic status as an independent risk factor for hospital readmission for heart failure

The management of heart failure is characterized by high rates of hospital admission as well as rehospitalization after inpatient treatment of this disorder, whereas skillful medical care may reduce the risk of hospital admission. The purpose of this study was to examine the relation between income (as a measure of socioeconomic status) and the frequency of hospital readmission among a large and diverse group of persons treated for heart failure. We analyzed administrative discharge data from 236 nonfederal acute-care hospitals in New York State, involving 41,776 African-American or Caucasian hospital survivors with International Classification of Diseases, Ninth Revision, Clinical Modification codes for heart failure in the principal diagnosis position between January 1 and December 31, 1995. Household income was derived from postal ZIP codes and census data. We found that patients residing in lower income neighborhoods were more often women or African-Americans, had more comorbid illness, had higher use of Medicaid insurance, and were more often admitted to rural hospitals. There was a stepwise decrease in the crude frequency of readmission from the lowest quartile of income (23.2%) to the highest (20.0%) (p <0.0001 for Mantel-Haenszel chi-square test for trend across all quartiles; p <0.0001 for comparison between quartiles 1 and 4). After adjustment for baseline differences and process of care, income remained a significant predictor, with an increase in the risk of readmission noted in association with lower levels of income (adjusted odds ratio for quartile 1:4 comparison, 1.18; 95% confidence interval, 1.10 to 1.26, p <0.0001). We conclude that lower income patients hospitalized for treatment of heart failure in New York differ from higher income patients in important clinical and demographic comparisons. Even after adjustment for these fundamental differences and other potential confounding factors, lower income is a positive predictor of readmission risk.

Complement activation products in plasma after heart transplantation in humans

BACKGROUND

Complement activation has recently been implicated as a contributing factor to early and late allograft dysfunction in cardiac transplantation. The current study was designed to determine whether measurement of plasma complement fragments C4d and SC5b-9 would be useful in detecting acute rejection or accelerated graft atherosclerosis (AGA) in cardiac allograft recipients.

METHODS

We measured complement activation products, C4d (classical pathway) and SC5b-9 (terminal pathway), at the time of routine endomyocardial biopsy in heart transplant recipients. Ten patients in the immediate posttransplantation period (0-100 days) and 19 patients more than 6 months after transplantation were studied.

RESULTS

No correlation was found between plasma levels of complement activation fragments and the presence of biopsy-proven acute allograft rejection or AGA (assessed by coronary angiography). However, plasma C4d and SC5b-9 were significantly elevated in 9 of 10 and 7 of 10 patients, respectively, in the immediate posttransplantation period. This was followed by progressive decrease in the levels of C4d and SC5b-9 fragments during the first 4-6 weeks after transplantation.

CONCLUSION

We conclude that measuring plasma levels of fragments C4d and SC5b-9 is not a useful noninvasive method for detecting acute rejection or AGA after heart transplantation. However, this study provides further evidence that early complement activation after heart transplantation may play a pathogenic role in allograft injury.

Controlled trial of intravenous immune globulin in recent-onset dilated cardiomyopathy

BACKGROUND

This prospective placebo-controlled trial was designed to determine whether intravenous immune globulin (IVIG) improves left ventricular ejection fraction (LVEF) in adults with recent onset of idiopathic dilated cardiomyopathy or myocarditis.

METHODS AND RESULTS

Sixty-two patients (37 men, 25 women; mean age +/-SD 43.0+/-12.3 years) with recent onset (</=6 months of symptoms) of dilated cardiomyopathy and LVEF </=0.40 were randomized to 2 g/kg IVIG or placebo. All underwent an endomyocardial biopsy before randomization, which revealed cellular inflammation in 16%. The primary outcome was change in LVEF at 6 and 12 months after randomiz. Overall, LVEF improved from 0.25+/-0.08 to 0.41+/-0.17 at 6 months (P<0.001) and 0.42+/-0.14 (P<0.001 versus baseline) at 12 months. The increase was virtually identical in patients receiving IVIG and those given placebo (6 months: IVIG 0.14+/-0.12, placebo 0.14+/-0.14; 12 months: IVIG 0.16+/-0.12, placebo 0.15+/-0.16). Overall, 31 (56%) of 55 patients at 1 year had an increase in LVEF >/=0.10 from study entry, and 20 (36%) of 56 normalized their ejection fraction (>/=0.50). The transplant-free survival rate was 92% at 1 year and 88% at 2 years.

CONCLUSIONS

These results suggest that for patients with recent-onset dilated cardiomyopathy, IVIG does not augment the improvement in LVEF. However, in this overall cohort, LVEF improved significantly during follow-up, and the short-term prognosis remains favorable.

Socioeconomic status is an important determinant of the use of invasive procedures after acute myocardial infarction in New York State

BACKGROUND

Patient and hospital characteristics influence the use of invasive cardiac procedures. Whether socioeconomic status (SES) has an influence that is independent of these other determinants is unclear. The purpose of the present study was to examine the influence of household income as a measure of SES on the use of invasive cardiac procedures among a large group of patients with acute myocardial infarction.

METHODS AND RESULTS

We analyzed administrative discharge data from 231 nonfederal acute care hospitals in New York State that involved 28 698 black or white inpatients with International Classification of Diseases, Ninth Revision, Clinical Modification code 410.XX in the principal diagnosis position between January 1 and December 31, 1995. Household income was derived from postal ZIP codes and census data. The use of cardiac catheterization, PTCA, CABG, and any revascularization procedure was examined across groups stratified by income. Patients who resided in lower-income neighborhoods were more often female or black, had a higher prevalence of coexistent illness, had a higher use of Medicaid insurance, and were less often admitted to urban hospitals or hospitals that provide on-site CABG and PTCA. Crude and adjusted odds ratios for catheterization, PTCA, CABG, and any revascularization procedure were related to income in a graded fashion. After adjustment, patients in the highest quintile of income were 22% more likely to undergo catheterization, 74% more likely to undergo PTCA, 48% more likely to undergo CABG, and 76% more likely to undergo any revascularization procedure than were patients in the lowest quintile. The difference in cardiac catheterization did not fully account for income-based differences in revascularization, because income remained a significant determinant of revascularization after accounting for whether a catheterization was performed. Even among patients treated in hospitals that provide on-site CABG and PTCA, income was a significant determinant of procedures.

CONCLUSIONS

Lower-income patients hospitalized for acute myocardial infarction are more often female or black, have more coexisting illnesses, and are less often admitted to urban hospitals or hospitals that provide CABG and PTCA. Even after adjustment for these and other factors, lower income is a negative predictor of procedure use.

Expression of proinflammatory cytokines in the failing human heart: comparison of recent-onset and end-stage congestive heart failure

BACKGROUND

Plasma levels of proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, are elevated in patients with congestive heart failure (CHF). Recent studies suggest that the failing human heart is a source of proinflammatory cytokines in the end-stage failing heart. However, the relevance of plasma levels to those of the myocardium remains undefined. We sought to compare cytokine expression in early and end-stage CHF, and to evaluate the correlation of tissue expression to plasma levels.

METHODS

Two patient populations were studied: patients with recent-onset CHF, all with symptoms less than 6 months (n = 17, duration of symptoms 2.1 +/- 1.6 months, range of New York Heart Association (NYHA) 1 to 3), and end-stage heart-failure patients (n = 7) who underwent left-ventricular assist-device (LVAD) implantation (Duration of symptoms 47.1 +/- 28.0 months, all NYHA class 4). Plasma levels of TNF-alpha and IL-6 proteins were evaluated by an Enzyme-Linked Immuno-Sorbent Assay (ELISA), while myocardial levels of cytokine transcripts were assessed by ribonuclease (Rnase) protection assay.

RESULTS

In patients with end-stage heart failure, TNF-alpha and IL-6 were increased in the plasma as well as in the myocardium (plasma: TNF-alpha = 7.7 +/- 2.3 pg/ml, IL-6 = 45.0 +/- 47.1 pg/ml; myocardium: TNF-alpha = 0.31 +/- 0.15% of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, IL-6 = 1.56 +/- 1.54% ). In contrast, despite elevated plasma levels of TNF-alpha and IL-6, the myocardium of patients with the recent onset of symptoms demonstrated minimal expression of TNF-alpha and IL-6 messenger ribonucleic acid (mRNA) (plasma: TNF-alpha = 4.3 +/- 1.7 pg/ml, IL-6 = 3.3 +/- 1.8 pg/ml; myocardium: TNF-alpha = 0.13 +/- 0. 04%, IL-6 = 0.02 +/- 0.04%). Plasma levels of TNF-alpha were significantly correlated with those in the myocardium when both populations were combined. (r = 0.69, p < 0.001).

CONCLUSIONS

Cytokines are expressed in the myocardium in end-stage heart failure to a much greater degree than in patients with the recent-onset of symptoms. This suggests that induction of cytokines in the myocardium is a relatively late event in the pathogenesis of CHF. Furthermore, plasma levels of TNF-alpha correlates with mRNA expression in the myocardium and thus may serve as an appropriate marker of myocardial cytokine activation. Whether the production of cytokines in the failing human heart precedes the elevation of cytokines in the plasma remains undefined. Therefore, we studied expression of TNF-alpha and IL-6 in the myocardium as well as in the plasma in patients with early and end-stage CHF. The results have demonstrated that cytokines are expressed in the myocardium in end-stage heart failure to a much greater degree than in patients with the recent onset of symptoms. This suggests that induction of cytokines in the myocardium is a relatively late event in the pathogenesis of CHF.

Low-dose enoximone improves exercise capacity in chronic heart failure. Enoximone Study Group

OBJECTIVES

This study was designed to evaluate the effects of low-dose enoximone on exercise capacity.

BACKGROUND

At higher doses the phosphodiesterase inhibitor, enoximone, has been shown to increase exercise capacity and decrease symptoms in heart failure patients but also to increase mortality. The effects of lower doses of enoximone on exercise capacity and adverse events have not been evaluated.

METHODS

This is a prospective, double-blind, placebo-controlled, multicenter trial (nine U.S. centers) conducted in 105 patients with New York Heart Association class II to III, ischemic or nonischemic chronic heart failure (CHF). Patients were randomized to placebo or enoximone at 25 or 50 mg orally three times a day. Treadmill maximal exercise testing was done at baseline and after 4, 8 and 12 weeks of treatment, using a modified Naughton protocol. Patients were also evaluated for changes in quality of life and for increased arrhythmias by Holter monitoring.

RESULTS

By the protocol-specified method of statistical analysis (the last observation carried-forward method), enoximone at 50 mg three times a day improved exercise capacity by 117 s at 12 weeks (p = 0.003). Enoximone at 25 mg three times a day also improved exercise capacity at 12 weeks by 115 s (p = 0.013). No increases in ventricular arrhythmias were noted. There were four deaths in the placebo group and 2 and 0 deaths in the enoximone 25 mg three times a day and enoximone 50 mg three times a day groups, respectively. Effects on degree of dyspnea and patient and physician assessments of clinical status favored the enoximone groups.

CONCLUSIONS

Twelve weeks of treatment with low-dose enoximone improves exercise capacity in patients with CHF, without increasing adverse events.

Ten-year trends in hospital care for congestive heart failure: improved outcomes and increased use of resources

BACKGROUND

Scarce data are available on long-term trends in hospital mortality, length of stay (LOS), and costs in congestive heart failure (CHF).

OBJECTIVE

To assess 10-year trends in the outcomes of patients hospitalized with CHF.

METHODS

We studied all 6676 patients with a primary discharge diagnosis of CHF hospitalized from January 1, 1986, through July 31, 1996, at an academic tertiary care center. Hospital mortality, LOS, and costs were adjusted for sociodemographic characteristics, comorbidities, invasive procedures, hospital disposition, and LOS where appropriate.

RESULTS

The mean (+/- SD) age of patients was 70+/-13 years; 54.1% were male; 87.0% were white. There was a significant increasing trend in heart failure severity as assessed by a CHF-specific risk-adjustment index. The proportion of patients who underwent invasive procedures (e.g., cardiac catheterization, coronary angioplasty, coronary artery bypass surgery, defibrillator and pacemaker implantation) was significantly higher in the 1994-1996 period. The standardized mortality ratio (observed mortality/predicted mortality) progressively fell during the study period. Compared with patients admitted before 1991, those admitted after 1991 had a 24% lower observed than predicted mortality. Adjusted LOS exhibited a downward trend, ie, 7.7 days in 1986-1987 to 5.6 days in 1994-1996 (P<.001). Unadjusted cost peaked during 1992-1993 and declined thereafter. Adjusted costs in 1994-1996 were not significantly different from those in 1990-1991.

CONCLUSIONS

After risk adjustment for sociodemographic characteristics, comorbidities, and disease severity, a significant decrease in in-hospital mortality was observed during the study decade. This decline in hospital mortality occurred in parallel with decreasing LOS and increasing use of cardiac procedures and costs.

Combined immunosuppression for the treatment of idiopathic giant cell myocarditis

Giant cell myocarditis (GCM) is a rare and frequently fatal disorder with no proven treatment. Case reports and data from a rat model of GCM suggest that immunosuppressive therapy directed against T lymphocytes may have clinical benefit. We describe a 47-year-old man with severe acute heart failure due to GCM in whom the left ventricular ejection fraction normalized and the myocardial inflammatory infiltrate resolved rapidly after treatment with muromonab-CD3, cyclosporine, azathioprine, and corticosteroids. Three previously published cases with less impressive responses to treatment including muromonab-CD3 and a critical review of the published data on immunosuppressive therapy are included in this report. The response to immunosuppressive therapy is highly variable, and direct comparisons between immunosuppressive regimens do not exist. Therefore, despite individual reports of dramatic improvement after immunosuppressive treatment, firm conclusions cannot be made about the benefit of immunosuppression for GCM. The benefits of immunosuppressive therapy must be confirmed in a prospective, randomized trial.

Ventricular remodeling in active myocarditis. Myocarditis Treatment Trial

BACKGROUND

Remodeling of the left ventricle with the development of a spherical cavity occurs in dilated cardiomyopathy and is associated with a poor long-term prognosis. The early effects of myocarditis on left ventricular geometry have not been previously described or correlated with clinical outcome.

METHODS

The baseline echocardiograms of 35 patients with biopsy-confirmed myocarditis were compared with 20 normal controls. Left ventricular end-diastolic volume, long axis length, and mid-cavity diameter were measured. The degree of sphericity was expressed as the ratio of the mid-cavity diameter to the long axis length. Left ventricular ejection fraction was assessed by radionuclide angiography.

RESULTS

In patients with myocarditis, mean left ventricular volume of 81 +/- 29 mL/m(2) was significantly greater than 50 +/- 8 mL/m(2) in controls (P =.001). Chamber dilatation occurred primarily along the mid-cavity diameter, which measured 5.3 +/- 0.8 cm in patients with myocarditis versus 4.2 +/- 0.4 cm in controls (P =.001). The degree of left ventricular sphericity in patients with myocarditis, 0.64 +/- 0.08, was significantly greater than that of controls, 0.54 +/- 0.04 (P =.001). When patients were stratified according to left ventricular volume, patients with increased left ventricular volume (>75 mL/m(2)) were associated with a more spherical chamber and lower left ventricular ejection fraction than patients with a more normal left ventricular volume (</=75 mL/m(2)).

CONCLUSIONS

Active myocarditis is associated with early left ventricular remodeling and the development of a spherical chamber. These changes correlate with ventricular dilatation and reduced left ventricular ejection fraction.

Apoptosis in heart failure: release of cytochrome c from mitochondria and activation of caspase-3 in human cardiomyopathy

Apoptosis has been shown to contribute to loss of cardiomyocytes in cardiomyopathy, progressive decline in left ventricular function, and congestive heart failure. Because the molecular mechanisms involved in apoptosis of cardiocytes are not completely understood, we studied the biochemical and ultrastructural characteristics of upstream regulators of apoptosis in hearts explanted from patients undergoing transplantation. Sixteen explanted hearts from patients undergoing heart transplantation were studied by electron microscopy or immunoblotting to detect release of mitochondrial cytochrome c and activation of caspase-3. The hearts explanted from five victims of motor vehicle accidents or myocardial ventricular tissues from three donor hearts were used as controls. Evidence of apoptosis was observed only in endstage cardiomyopathy. There was significant accumulation of cytochrome c in the cytosol, over myofibrils, and near intercalated discs of cardiomyocytes in failing hearts. The release of mitochondrial cytochrome c was associated with activation of caspase-3 and cleavage of its substrate protein kinase C delta but not poly(ADP-ribose) polymerase. By contrast, there was no apparent accumulation of cytosolic cytochrome c or caspase-3 activation in the hearts used as controls. The present study provides in vivo evidence of cytochrome c-dependent activation of cysteine proteases in human cardiomyopathy. Activation of proteases supports the phenomenon of apoptosis in myopathic process. Because loss of myocytes contributes to myocardial dysfunction and is a predictor of adverse outcomes in the patients with congestive heart failure, the present demonstration of an activated apoptotic cascade in cardiomyopathy could provide the basis for novel interventional strategies.

Pattern of changes over time in myocardial blood flow and microvascular dilator capacity in patients with normally functioning cardiac allografts

This study tests the hypothesis that myocardial blood flow and coronary microvascular dilator capacity vary as a function of time after orthotopic heart transplantation in humans. Positron emission tomography measurements of myocardial blood flow were obtained at rest and during adenosine in 24 patients between 1 and 86 months after heart transplantation. At the time of the study all patients were clinically well and had angiographically normal epicardial coronary artery vessels. Patients were divided into 3 groups based on time from transplant to positron emission tomography measurement of myocardial blood flow: group 1 to 12 months (n = 9); group 13 to 34 months (n = 8); and group > or = 37 months (n = 7). Basal myocardial blood flow in group 1 to 12 months (1.86+/-1.01 ml/min/g) exceeded (p <0.05) that of group 13 to 34 months (1.17+/-0.73) and group > or = 37 months (0.98+/-0.34). In group 13 to 34 months, basal myocardial blood flow and maximal dilator capacity (minimal coronary vascular resistance with adenosine 36+/-12 mm Hg/ml/min/g) were comparable to that of normal volunteers (1.01+/-0.20 and 37+/-, respectively). In group > or = 37 months, maximal flow response to adenosine was reduced (2.54+/-1.25 vs 3.16+/-0.52, respectively, p = 0.06). Maximal dilator capacity in group > or = 37 months (60+/-34) was impaired versus group 1 to 12 months (36+/-10) and group 13 to 34 months (36+/-12; both p <0.05) as well as normals (37+/-9, p <0.05). During the first year after cardiac transplantation basal myocardial blood flow is elevated out of proportion to external determinants of myocardial oxygen demand, but maximal dilator capacity of the coronary microcirculation is normal. Between 1 and 3 years both basal myocardial blood flow and microvascular function tend to normalize. After 3 years, although basal myocardial blood flow is normal, microvascular dilator capacity is impaired.

Usefulness of echocardiographic determined tricuspid regurgitation in predicting event-free survival in severe heart failure secondary to idiopathic-dilated cardiomyopathy or to ischemic cardiomyopathy

Two-dimensional and color Doppler echocardiograms obtained in 117 patients during cardiac transplantation evaluation were reviewed. Right ventricular hypokinesia and dilation were more prevalent in patients with tricuspid regurgitation. In multivariate event-free survival analysis of 61 patients with complete clinical, echocardiographic, and cardiopulmonary exercise data, the absence of tricuspid regurgitation and New York Heart Association class were the only independent predictors of survival.

Apoptosis in the failing heart

Apoptosis is a tightly regulated, energy-requiring process of programmed cell death. While necrosis is a form of cell death that results from acute cellular injury, apoptosis is controlled autodigestion of the cell that occurs through activation of endogenous proteases. This process results in the cleavage of chromatin into oligonucleosome-length DNA fragments and its multiples. This DNA fragmentation demonstrates a characteristic laddering pattern on DNA agarose gel electrophoresis. The heart undergoes extensive remodeling during embryogenesis wherein apoptosis significantly contributes to the development of the cardiac chambers and correct routing of the great vessels. Pathologic stimuli can also result in apoptosis and include ischemia, hypoxia, inflammation, cytokines, growth factors, and toxic agents. Better understanding of the molecular mechanisms responsible for regulating apoptosis in the failing myocardium may soon lead to strategies aimed at preventing further myocyte loss and enhancing myocyte replacement through regulated cell growth.

Effect of vesnarinone on cardiac function in patients with severe congestive heart failure

BACKGROUND

Vesnarinone has yielded controversial results on morbidity in patients with congestive heart failure. We tested the hypothesis that vesnarinone may have a beneficial effect on cardiac remodeling and function.

METHODS

Thirty-four patients with left ventricular ejection fraction (LVEF) <30% (17 treated with vesnarinone) underwent an echocardiography at baseline and at 12+/-5 months. Left ventricular end-diastolic and end-systolic volume, mitral regurgitation, diastolic filling, and right ventricular area change were quantified and compared.

RESULTS

When the vesnarinone group was considered as a whole, there was no significant effect of vesnarinone on cardiac systolic and diastolic function or remodeling. However, an increase in LVEF >7% was observed in six of the vesnarinone patients and none of the control group. Vesnarinone improved right and left ventricular systolic function significantly in patients with initial LVEF <25%.

CONCLUSIONS

In severe congestive heart failure, vesnarinone induces variable responses but improves biventricular performance in patients with the most impaired initial function.

Palpitations and cardiac awareness after heart transplantation

OBJECTIVE

The aim of this study was to examine the awareness of resting heartbeat in heart transplantation recipients, compare it with that found in other medical populations, and determine whether clinical characteristics are associated with accurate heartbeat awareness.

METHODS

Eligible patients underwent a research battery consisting of a heartbeat detection task and self-report questionnaires assessing cardiac symptoms, psychosocial variables, and cognitive function. The accurate awareness of resting heartbeat was determined by presenting the patients with auditory stimuli at each of six different delays following the R wave on the ECG. Patients then selected the tones that they thought coincided with the sensation they had of their heart beating. The patients' physicians rated their cardiac morbidity. The results were contrasted with comparable data obtained in previous work with other ambulatory medical populations.

RESULTS

Forty-one consecutive heart transplantation recipients who survived for at least 3 months after surgery were eligible. Thirty-four (82.9%) of them were studied and complete data were obtained on 26 (63.4%). Nine patients (34.6%) were reliably able to detect their resting heartbeat. When compared with the 17 patients who were not accurately aware of their heartbeat, the two groups did not differ significantly in cardiac morbidity, cognitive brain dysfunction, generalized psychiatric distress, depression, somatization, or hypochondriacal attitudes. A significantly higher proportion of heart transplantation recipients were accurately aware of their heartbeat than was found in a sample of general medical outpatients and in asymptomatic, nonpatient volunteers.

CONCLUSIONS

One-third of heart transplant recipients are accurately aware of resting heartbeat, despite the absence of cardiac innervation.

Heart transplant coronary artery disease detected by coronary angiography: a multiinstitutional study of preoperative donor and recipient risk factors. Cardiac Transplant Research Database

BACKGROUND

Controversy exists regarding donor and recipient factors that promote the development and progression of coronary artery disease after heart transplantation and the likelihood of coronary artery disease causing death or retransplantation.

METHODS

To investigate this issue in a large cohort of patients, we analyzed 5963 postoperative angiograms performed in 2609 of the 3837 patients undergoing heart transplantation at 39 institutions between January 1990 and December 1994. Coronary artery disease was classified as mild, moderate, or severe on the basis of left main involvement, primary vessel stenoses, and branch stenoses. Coronary artery disease was considered severe if left main stenosis was > 70% or 2 or more primary vessels stenoses were > 70% or branch stenoses were > 70% in all 3 systems.

RESULTS

By the end of 5 years after heart transplantation, coronary artery disease was present in 42% of the patients, mild in 27%, moderate in 8%, and severe in 7%. Coronary artery disease-related events (death or retransplantation) had an actuarial incidence of 7% at 5 years and occurred in 2 of 3 of the patients with development of angiographically severe coronary artery disease. By multivariable logistic analysis, risk factors for donor coronary artery disease included older donor age (P < .0001) and donor hypertension (P=.0002). By multivariable analysis in the hazard function domain, risk factors identified for the earlier onset of allograft coronary artery disease included older donor age (P < .0001 ), donor male sex (P=.0006), donor hypertension (P=.07), recipient male sex (P=.02), and recipient black race (P=.01). The actuarial incidence of severe coronary artery disease was 9% at 5 years.

CONCLUSIONS

Angiographic coronary artery disease is very common after heart transplantation, occurring in approximately 42% of the patients by 5 years. Older donor age, donor hypertension, and male donor or recipient predict earlier onset of angiographic allograft coronary artery disease. Although severe angiographic allograft coronary artery disease occurs in only 7% of the patients at 5 years, its presence is highly predictive of subsequent coronary artery disease-related events or retransplantation.

Coronary endothelial dysfunction in patients with acute-onset idiopathic dilated cardiomyopathy

OBJECTIVES

This study sought to determine whether coronary endothelial dysfunction exists in patients with acute-onset idiopathic dilated cardiomyopathy (DCM) and to explore its relation to recovery of left ventricular systolic function in this patient population.

BACKGROUND

Coronary endothelial dysfunction exists in chronic DCM, but its importance in the development and progression of ventricular dysfunction is not known. To address this issue we studied coronary endothelial function in patients with idiopathic DCM <6 months in duration and explored the relation between coronary endothelial function and subsequent changes in left ventricular ejection fraction (LVEF).

METHODS

Ten patients with acute-onset idiopathic DCM (duration of heart failure symptoms 2.0 +/- 0.4 months [mean +/- SEM]) and 11 control patients with normal left ventricular function underwent assessment of coronary endothelial function during intracoronary administration of the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator adenosine. Coronary cross-sectional area (CSA) was determined by quantitative coronary angiography and coronary blood flow (CBF) by the product of coronary CSA and CBF velocity measured by an intracoronary Doppler catheter. Patients with DCM underwent assessment of left ventricular function before and several months after the study.

RESULTS

Acetylcholine infusion produced no change in coronary CSA in control patients but significant epicardial constriction in patients with DCM (-36 +/- 11%, p < 0.01). These changes were associated with increases in CBF in control patients (+118 +/- 49%, p < 0.01) but no change in patients with DCM. Infusion of adenosine produced increases in coronary caliber and blood flow in both groups. Follow-up assessment of left ventricular function was obtained in nine patients with DCM 7.0 +/- 1.7 months after initial study, at which time LVEF had improved by > or =0.10 in four patients. Multiple linear regression revealed a positive correlation between both the coronary CSA (r2 = 0.57, p < 0.05) and CBF (r2 = 0.68, p < 0.01) response to acetylcholine and the subsequent improvement in LVEF.

CONCLUSIONS

Coronary endothelial dysfunction exists at both the microvascular and the epicardial level in patients with acute-onset idiopathic DCM. The preservation of coronary endothelial function in this population is associated with subsequent improvement in left ventricular function.

Inhaled nitric oxide improves exercise capacity in patients with severe heart failure and right ventricular dysfunction

Fourteen cardiac transplant candidates were studied with cardiopulmonary exercise testing at baseline and while breathing nitric oxide (40 ppm). Oxygen consumption at the anaerobic threshold was improved by breathing nitric oxide in patients with pulmonary hypertension and in patients with an elevated left ventricular end-diastolic volume index.

Modulation of ventricular function through gene transfer in vivo

We used a catheter-based technique to achieve generalized cardiac gene transfer in vivo and to alter cardiac function by overexpressing phospholamban (PL) which regulates the activity of the sarcoplasmic reticulum Ca2+ ATPase (SERCA2a). By using this approach, rat hearts were transduced in vivo with 5 x 10(9) pfu of recombinant adenoviral vectors carrying cDNA for either PL, beta-galactosidase (beta-gal), or modified green fluorescent protein (EGFP). Western blot analysis of ventricles obtained from rats transduced by Ad.PL showed a 2.8-fold increase in PL compared with hearts transduced by Ad.betagal. Two days after infection, rat hearts transduced with Ad.PL had lower peak left ventricular pressure (58.3 +/- 12.9 mmHg, n = 8) compared with uninfected hearts (92.5 +/- 3.5 mmHg, n = 6) or hearts infected with Ad.betagal (92.6 +/- 5.9 mmHg, n = 6). Both peak rate of pressure rise and pressure fall (+3, 210 +/- 298 mmHg/s, -2, 117 +/- 178 mmHg/s, n = 8) were decreased in hearts overexpressing PL compared with uninfected hearts (+5, 225 +/- 136 mmHg/s, -3, 805 +/- 97 mmHg/s, n = 6) or hearts infected with Ad.betagal (+5, 108 +/- 167 mmHg/s, -3, 765 +/- 121 mmHg/s, n = 6). The time constant of left ventricular relaxation increased significantly in hearts overexpressing PL (33.4 +/- 3.2 ms, n = 8) compared with uninfected hearts (18.5 +/- 1.0 ms, n = 6) or hearts infected with Ad.betagal (20.8 +/- 2.1 ms, n = 6). These differences in ventricular function were maintained 7 days after infection. These studies open the prospect of using somatic gene transfer to modulate overall cardiac function in vivo for either experimental or therapeutic applications.

Left ventricular end-diastolic volume index, age, and maximum heart rate at peak exercise predict survival in patients referred for heart transplantation

BACKGROUND

This study sought to define clinical predictors of survival in patients under consideration for heart transplantation and demonstrate possible improvements in the prediction of outcome when considering the identified predictors in addition to peak oxygen consumption. Peak oxygen consumption is currently the most important criterion for determining the timing and appropriateness of heart transplantation in ambulatory patients.

METHODS

To identify other possible predictors of survival in patients with heart failure, we reviewed clinical, exercise, and radionuclide ventriculographic data on 112 patients referred for heart transplantation evaluation. Predictors of 1-year (n = 86) and overall (n = 112) survival to the combined end point of freedom from death or pretransplantation admission for inotropic or mechanical support were identified in multivariate analysis.

RESULTS

The mean age was 51+/-9 years, and the mean duration of follow-up was 408+/-366 days. The mean left ventricular ejection fraction was 0.22+/-0.07, and the mean peak oxygen consumption was 12.3+/-3.7 ml/min/kg. Age (odds ratio 1.087, 95% confidence interval [CI] 1.021 to 1.157), percentage of the maximum predicted heart rate at peak exercise (odds ratio 0.958, 95% CI 0.924 to 0.992), and left ventricular end-diastolic volume index (odds ratio 1.019, 95% CI 1.006 to 1.033) were independent predictors of the 1-year combined end point.

CONCLUSION

Age, heart rate at peak exercise, and left ventricular end-diastolic volume index are independent predictors of prognosis in patients with advanced heart failure and may provide additional prognostic information for the risk-stratification of potential heart transplant recipients.

Clinical correlates of the myocardial force-frequency relationship in patients with end-stage heart failure

BACKGROUND

This study tested the hypothesis that in patients with suspected heart failure, peak oxygen consumption was the best predictor of heart muscle failure. Failing human myocardium is characterized by an abnormal force-frequency relationship, which has been previously shown to be altered in parallel with the severity of heart failure.

METHODS

We examined whether seven different functional parameters of isolated electrically driven ventricular trabeculae carneae obtained from 34 explanted hearts of patients undergoing heart transplantation for end-stage heart failure correlated with any of 47 separate pretransplantation clinical parameters. The functional muscle parameters were active force at 0.33 Hz, time to 80% relaxation (RT 80%) of twitch force at 0.33 Hz, optimal frequency (OF), active force at 1.0 Hz (AF1), diastolic force at 1.0 Hz (DF1), active force at 2.0 Hz (AF2), and diastolic force at 2.0 Hz (DF2).

RESULTS

Before transplantation the mean left ventricular ejection fraction was 21% +/- 10%, and all patients were in New York Heart Association class III or IV. Mean peak whole body VO2 was 10.9 +/- 3.3 ml/min/kg and percent body mass/age/sex-adjusted maximum VO2 oxygen consumption was 34.7% +/- 10.4%. Univariate analysis of VO2 yielded the following significant correlations: active force at 33 Hz, RT80%, OF, AF1, DF1, AF2, DF2; whereas univariate analysis of percent body mass/age/sex-adjusted VO2 yielded the following significant correlations: RT80%, OF, DF1, AF2, DF2. Multivariate analysis showed that OF and DF1 were independent predictors of peak VO2.

CONCLUSION

In this study we show that peak oxygen uptake measured during cardiopulmonary exercise testing obtained before transplantation is correlated with the force-frequency behavior of isolated muscles at the time of transplantation. Peak VO2 seems to be a strong indicator of the severity of cardiac contractile dysfunction in patients with heart failure.

Sex and left ventricular volume predict survival in heart transplant candidates with peak oxygen uptake between ten and fourteen milliliters per kilogram per minute

BACKGROUND

The purpose of this study was to identify predictors of survival in patients referred for heart transplantation evaluation who had a peak oxygen uptake of 10 to 14 ml/kg/min measured during initial cardiopulmonary exercise testing.

METHODS

Seventy-two patients were identified retrospectively from a database of 304 patients who underwent heart transplantation evaluations at our center from 1985 to 1995. All 72 patients underwent right-sided heart catheterization and first-pass right and left ventricular radionuclide ventriculography during cardiopulmonary exercise testing.

RESULTS

There were 14 women and 58 men in the study (mean age 52 +/- 9 years, 80% male, 79% New York Heart Association class III/IV, left ventricular ejection fraction of 0.24 +/- 0.9, and left ventricular end-diastolic volume index of 144 +/- 59 ml). During a mean follow-up of 19 +/- 23 months, two women and 32 men (47%) reached the combined end point of death (n = 20) or pretransplantation admission for inotropic or mechanical support (n = 14). For the entire cohort, analysis of clinical, ventriculographic, and exercise parameters identified female sex, younger age, and age/ sex-adjusted peak oxygen uptake as independent predictors of survival. In men only, age, left ventricular end-diastolic volume index, and age/sex adjusted peak oxygen uptake were independent predictors of survival.

CONCLUSIONS

Among patients referred for heart transplantation evaluation with a peak oxygen uptake between 10 to 14 ml/kg/min, younger age, female sex, and higher age/ sex-adjusted peak oxygen uptake predict longer survival to the combined end point of death or pretransplantation admission for inotropic or mechanical support. These measures may be useful in additional risk stratification of such patients.

Inspiratory muscle training in patients with chronic heart failure awaiting cardiac transplantation: results of a pilot clinical trial

BACKGROUND AND PURPOSE

Persons with chronic heart failure (HF) have poor ventilatory muscle strength, and this weakness is associated with dyspnea. The purpose of this study was to examine the effects of inspiratory muscle training (IMT) on ventilatory muscle strength and dyspnea in patients with chronic HF.

SUBJECTS

Fourteen patients (mean age [+/-SD] = 52 +/- 8.5 years) with end-stage cardiomyopathy and chronic HF (mean left ventricular ejection fraction = 23% +/- 13% and New York Heart Association class = 3.6 +/- 0.6) participated in the study.

METHODS

Inspiratory muscle training was performed at 20% of maximal inspiratory pressure (MIP) for 5 to 15 minutes, three times a day, for 8 weeks. Dyspnea was evaluated at rest and during exercise.

RESULTS

Both MIP and maximal expiratory pressure (MEP) were greater after 2 weeks of IMT (51 +/- 21 to 63 +/- 23 cm H2O and 85 +/- 22 to 96 +/- 19 cm H2O, representing 24% and 13% improvement). Dyspnea scores at rest and during exercise decreased after 2 weeks (2.0 +/- 0.7 to 1.3 +/- 0.5 and 3.6 +/- 0.5 to 2.6 +/- 0.6, representing 29% and 28% improvement) and plateaued throughout the remainder of IMT. Baseline MEP was related to the percentage of change in MEP after IMT (r = -.72), and several measures of pulmonary function were related to the degree of improvement in dyspnea after IMT (r = -.57 to -.82) and in MIP after IMT (r = .71).

CONCLUSION AND DISCUSSION

Improvements in MIP, MEP, and dyspnea were found after 2 weeks of IMT. Greater pulmonary function was associated with greater improvement in dyspnea and ventilatory muscle strength after IMT. These improvements may decrease the dependency and impairment associated with chronic HF.

Relationship between pulmonary artery diameter at computed tomography and pulmonary artery pressures at right-sided heart catheterization. Massachusetts General Hospital Lung Transplantation Program

RATIONALE AND OBJECTIVES

The purpose of the study was to determine the relationship between pulmonary artery (PA) size at computed tomography (CT) and PA pressures, to develop a noninvasive CT method of PA pressure measurement, and to determine a PA diameter that can enable differentiation of normal subjects from those with pulmonary hypertension.

METHODS

PA vessel diameters in 55 candidates for lung and heart-lung transplantation were measured at CT and correlated with PA pressures with both linear and stepwise multiple regression. The multiple regression equations were then tested prospectively in 35 pretransplantation patients.

RESULTS

Combined main and left main PA cross-sectional area corrected for body surface area showed the best correlation with mean PA pressure (r = .87). The multiple regression equations helped predict mean PA pressure within 5 mm Hg in 50% of patients with chronic lung disease and in only 8% of patients with pulmonary vascular disease.

CONCLUSION

There was a very good correlation between main and left main PA size and mean PA pressure. At present, however, CT has not demonstrated sufficient accuracy to be used clinically.

Outcomes in recipients of combined heart-kidney transplantation: multiorgan, same-donor transplant study of the International Society of Heart and Lung Transplantation/United Network for Organ Sharing Scientific Registry

In patients awaiting heart transplantation, end-stage disease of a second organ may occasionally require consideration of simultaneous multiorgan transplantation. Outcome statistics in multiorgan transplant recipients are needed to define optimal utilization of scarce donor resources. Incidence of cardiac allograft rejection, actuarial recipient survival, and cardiac allograft rejection-free survival were evaluated in 82 recipients of 84 simultaneous heart and kidney transplants. Twenty-three of the 82 dual-organ recipients have died with 1, 6, 12, and 24-month actuarial survival rates of 92%, 79%, 76%, and 67%, respectively. The actuarial survival rates in the heart-kidney recipients were similar to those observed in 14,340 isolated heart recipients (United Network for Organ Sharing Scientific Registry) during the same period (92%, 86%, 83%, and 79%, respectively; P=0.20). Clinical data on all episodes of treated rejection in either organ and on immunosuppressive regimens were available on 56 patients; 48% of these patients have had no rejection in either organ, 27% experienced heart rejection alone, 14% experienced kidney rejection alone, and 11% had both heart and kidney allograft rejection. Heart allograft rejection was less common in heart-kidney recipients, as compared with isolated heart transplant recipients; 0, 1, and > or = 2 treated cardiac allograft rejection episodes occurred in 63%, 20%, and 18% of heart-kidney recipients compared with 46%, 27%, and 28% of 911 isolated heart recipients reported by Transplant Cardiologists' Research Database (P=0.02). The rejection-free survival rates at 1, 3, and 6 months were 88%, 74%, and 71% in the double-organ recipients, as compared with 66%, 44%, and 39%, respectively, in the single-organ recipients. Compared with isolated heart transplantation, combined heart-kidney transplantation does not adversely affect intermediate survival and results in a lower incidence of treated cardiac allograft rejection. The findings suggest that combined heart-kidney transplantation may be an acceptable option in a small subset of potential heart transplant recipients with severe renal dysfunction.

Apoptosis in myocytes in end-stage heart failure

BACKGROUND

Heart failure can result from a variety of causes, including ischemic, hypertensive, toxic, and inflammatory heart disease. However, the cellular mechanisms responsible for the progressive deterioration of myocardial function observed in heart failure remain unclear and may result from apoptosis (programmed cell death).

METHODS

We examined seven explanted hearts obtained during cardiac transplantation for evidence of apoptosis. All seven patients had severe chronic heart failure: four had idiopathic dilated cardiomyopathy, and three had ischemic cardiomyopathy. DNA fragmentation (an indicator of apoptosis) was identified histochemically by in situ end-labeling as well as by agarose-gel electrophoresis of end-labeled DNA. Myocardial tissues obtained from four patients who had had a myocardial infarction one to two days previously were used as positive controls, and heart tissues obtained from four persons who died in motor vehicle accidents were used as negative controls for the end-labeling studies.

RESULTS

Hearts from all four patients with idiopathic dilated cardiomyopathy and from one of the three patients with ischemic cardiomyopathy had histochemical evidence of DNA fragmentation. All four myocardial samples from patients with dilated cardiomyopathy also demonstrated DNA laddering, a characteristic of apoptosis, whereas this was not seen in any of the samples from patients with ischemic cardiomyopathy. Histological evidence of apoptosis was also observed in the central necrotic zone of acute myocardial infarcts, but not in myocardium remote from the infarcted zone. Rare isolated apoptotic myocytes were seen in the myocardium from the four persons who died in motor vehicle accidents.

CONCLUSIONS

Loss of myocytes due to apoptosis occurs in patients with end-stage cardiomyopathy and may contribute to progressive myocardial dysfunction.

Diagnostic accuracy of antimyosin scintigraphy in suspected myocarditis

BACKGROUND

Radiolabeled antibody specific for cardiac myosin administered intravenously has been used to define noninvasively regions of myocardial necrosis. Inflammatory heart disorders such as myocarditis and heart transplant rejection demonstrate diffuse and often faint myocardial uptake of antimyosin antibody. This study was undertaken to evaluate the reproducibility and diagnostic accuracy of antimyosin antibody imaging for the detection of patients with suspected myocarditis.

METHODS AND RESULTS

Fifty antimyosin scans, performed consecutively in patients with suspected myocarditis, were evaluated by one independent observer and two panels of observers. Antimyosin scan interpretations were compared with endomyocardial biopsy results and also with serial changes in left ventricular function. An independent observer (A) and a panel of five observers (A through E) interpreted the antimyosin scans as positive or negative on the basis of both planar images and tomographic reconstructions. Three of the five observers (A through C) again interpreted the scans but based interpretation only on planar images. Blinded random sequence evaluation of antimyosin scans based on the planar and tomographic interpretations revealed moderate agreement between the independent observer (A) and the group of observers (A through E) (kappa = 0.58). There was also moderate agreement between interpretations based on planar images alone and interpretations based on both planar and tomographic images (kappa [A through E]/[A through C] = 0.57; kappa [A through C]/A = 0.48). Comparison of antimyosin scan results with histologic evidence of myocarditis in endomyocardial biopsy specimens demonstrated that all scan results obtained from the individual or the panels of observers had a very high sensitivity (91% to 100%) and a high negative predictive value (93% to 100%). The specificity (31% to 44%) and positive predictive value (28% to 33%) were less impressive. We also compared the scan and biopsy results with the composite clinical standard of significant left ventricular functional improvement. Endomyocardial biopsy demonstrated poor sensitivity (35%) compared with antimyosin scans (82% to 94%) but had superior specificity (endomyocardial biopsy, 79%; antimyosin scan, 25% to 42%). The specificity of interpretations based on planar and tomographic interpretations (38% to 42%) was better than the planar images alone (25%). If reversible left ventricular dysfunction is considered clinical evidence of myocarditis, this study suggests that a negative endomyocardial biopsy significantly misses the presence of the disease. On the other hand, a negative antimyosin scan almost invariably excludes myocarditis.

CONCLUSIONS

This study demonstrates a high degree of interobserver reproducibility of antimyosin interpretation. Comparison of the scintigraphic results with histologic and clinical standards indicates a high sensitivity of antimyosin scans for the detection of myocarditis. The antimyosin scan is also not likely to miss clinically or pathologically diagnosed myocarditis, in contrast to the endomyocardial biopsy, which missed clinically validated myocarditis 65% of time. The combination of high sensitivity and negative predictive value suggests that antimyosin scintigraphy may be an effective screening procedure for obviating biopsies in patients with suspected myocarditis.

The six-minute walk test predicts peak oxygen uptake and survival in patients with advanced heart failure

BACKGROUND

The 6-min walk test (6'WT) is a simple measure of functional capacity and predicts survival in patients with moderate heart failure (HF).

METHODS

To assess the role of the 6'WT in the evaluation of patients with advanced HF, 45 patients (age 49 +/- 8 years, mean +/- SD; New York Heart Association class 3.3 +/- 0.6; left ventricular ejection fraction 0.20 +/- 0.06; right ventricular ejection fraction 0.31 +/- 0.11) underwent symptom-limited cardiopulmonary exercise testing and the 6'WT during cardiac transplant evaluation.

RESULTS

Mean 6'WT distance ambulated was 310 +/- 100 m and peak oxygen uptake (peak Vo2) was 12.2 +/- 4.5 mL/kg/min. There was a significant correlation between 6'WT distance ambulated and peak Vo2 (r = 0.64, p < 0.001). Multivariate analysis of patient characteristics, resting hemodynamics, and 6'WT results identified the distance ambulated during the 6'WT as the strongest predictor of peak Vo2 (p < 0.001). 6'WT distance ambulated less than 300 m predicted an increased likelihood of death or pretransplant hospital admission for continuous inotropic or mechanical support within 6 months (p = 0.04), but did not predict long-term overall or event-free survival with a mean follow-up of 62 weeks. Peak Vo2 was the best predictor of long-term overall and event-free survival.

CONCLUSIONS

In patients with advanced HF evaluated for cardiac transplantation, distance ambulated during the 6'WT predicts (1) peak Vo2 and (2) short-term event-free survival.

Biopsy-induced flail tricuspid leaflet and tricuspid regurgitation following orthotopic cardiac transplantation

Damage to the tricuspid valve apparatus has been described after endomyocardial biopsy and may be associated with hemodynamically significant tricuspid regurgitation (TR). This study was performed to determine the prevalence of TR and flail tricuspid leaflet in cardiac transplant recipients and to evaluate the use of a 45 cm sheath placed directly in the right ventricle during endomyocardial biopsy to reduce the incidence of these complications. Echocardiograms and right heart catheterization data of 72 orthotopic cardiac transplant recipients were assessed for the presence of flail tricuspid leaflet, TR, and right-sided cardiac dysfunction 29 +/- 20 months (mean +/- SD) after transplantation. Moderate or severe TR was present in 23 patients (32%). Ten patients (14%) had flail tricuspid leaflet, with 7 of these having severe TR. Right atrial pressure (10 +/- 5 vs 6 +/- 5 mm Hg, p < 0.05) was higher, cardiac index (2.0 +/- 0.2 vs 2.5 +/- 0.7 L/min/m2, p < 0.05) was lower, and right-sided cardiac dimensions were greater in patients with flail leaflets than in those without flail leaflets. Both the prevalence of flail tricuspid leaflet (41% to 6%, p < 0.0001) and mean grade of TR (2 to 1, p < 0.0001) were reduced after the use of a 45 cm sheath. We conclude that TR secondary to biopsy-induced damage to the valve apparatus occurs in cardiac transplant recipients and is associated with signs of early right-sided heart failure. Use of a 45 cm sheath during endomyocardial biopsy reduces the prevalence of flail tricuspid leaflet and the severity of TR.

Left ventricular dysfunction after heart transplantation: incidence and role of enhanced immunosuppression

BACKGROUND

The purpose of this study was to examine the incidence, natural history, and outcome of left ventricular dysfunction in 102 consecutive heart transplant recipients. Left ventricular dysfunction (defined as a decline in the echocardiographic ejection fraction to < 0.45) occurred in 16 of 102 transplant recipients (16%) at a mean of 9.7 +/- 8.6 (standard deviation) months after transplantation.

METHODS

Diagnostic evaluation included right heart catheterization and endomyocardial biopsy in all patients and coronary angiography in 13 patients.

RESULTS

Four patients were found to have moderate cellular rejection (International Society for Heart and Lung Transplantation grade 2 or higher) and were treated with enhanced immunosuppression. Two patients had angiographically apparent coronary allograft vasculopathy; both died of electromechanical dissociation within 4 months. The remaining ten patients had no or mild cellular rejection (International Society for Heart and Lung Transplantation grade 0 or 1). Therapy in these ten patients included corticosteroids (n = 8). OKT3 (n = 5), and plasmapheresis (n = 2). Three patients died within 2 months of diagnosis, two from undetected severe coronary allograft vasculopathy and one from unrecognized constrictive pericarditis. The echocardiographic ejection fraction improved in the surviving patients after enhanced immunosuppressive therapy (0.33 to 0.53, p < 0.005). With the benefit of long-term clinical follow-up and autopsy data, the origins of left ventricular dysfunction in the 16 patients included moderate cellular rejection (n = 4), vascular rejection (n = 1), coronary allograft vasculopathy (n = 3), intercurrent cytomegalovirus infection (n = 1), constrictive pericarditis (n = 1), and either mild or no evident rejection (n = 6). Survival of the 16 patients with left ventricular dysfunction was similar to that of the 86 patients without left ventricular dysfunction.

CONCLUSIONS

The cause of left ventricular dysfunction after heart transplantation includes cellular rejection, vascular rejection, coronary allograft vasculopathy, cytomegalovirus infection, constrictive pericarditis, and unexplained mechanisms. Given the improvement in left ventricular function observed after empiric therapy with enhanced immunosuppression in patients with left ventricular dysfunction, immune-mediated phenomena may play an important pathogenic role.

Cardiovascular complications following liver transplantation

BACKGROUND

As the indications for liver transplantation broaden to include older and more critically ill patients, the likelihood of encountering unsuspected cardiovascular disease increases.

PURPOSE

This study examined the frequency, type, and subsequent outcome of intra- and postoperative cardiovascular complications that occurred during the first 6 months following liver transplantation.

METHODS

The records of 146 consecutive patients who underwent primary liver transplantation were reviewed retrospectively to determine the occurrence of major (myocardial infarction or reversible ischemia, pulmonary edema, cardiogenic shock, symptomatic rhythm disturbances, or pulmonary embolism) and minor (transient hypertension, hypotension, atrial or ventricular premature beats) cardiac events. The relation between such events and actuarial patient survival was evaluated. Stepwise logistic regression analysis was also employed to identify those pre-operative variables that predicted an increased risk of postoperative events or mortality.

RESULTS

Cardiac events directly caused or contributed to 4 deaths (2.7%). Ventricular tachycardia/fibrillation was the most frequent intra-operative cardiac complication (3.4%); transient hypotension (post-reperfusion syndrome) was the most common minor event (20%). Thirty-four recipients (23%) developed a major postoperative cardiac complication including pulmonary edema (9%), myocardial ischemia or infarction (5.4%), new dilated cardiomyopathy (3.4%), and ventricular tachycardia (2.7%). Pre-existing cardiac disease and older age (mean age 49 +/- 8 years) at transplantation were the only independent predictors of a major complication. Major cardiac events did not affect 6 month survival but were associated with a lower 5-year survival rate (event: 32% vs event-free: 52%; p = 0.04). The frequency of major intraoperative (21% vs 2%; p = 0.0005) and postoperative (57% vs 17%; p = 0.0001) cardiac complications was significantly higher for recipients with known heart disease (Group A) compared with those without pre-existing heart disease (Group B). Five-year survival in Group A patients was 36% versus 50% for Group B patients; p = 0.45.

CONCLUSION

One or more cardiovascular complications occurred in over 70% of liver transplant recipients. Major events were associated with a lower likelihood of long-term survival. Older patients, particularly those with pre-existing but compensated heart disease, are at greatest risk for a major cardiac event and may require more extensive pre-operative risk assessment.

Influence of the implantable cardioverter/defibrillator on sudden death and total mortality in patients evaluated for cardiac transplantation

BACKGROUND

Implantable cardioverter/defibrillators (ICDs) may reduce sudden tachyarrhythmic death in patients with severe left ventricular dysfunction. It is uncertain whether this improves survival, particularly in patients awaiting cardiac transplantation.

METHODS AND RESULTS

The effect of treatment for spontaneous ventricular arrhythmias (ICD [n = 59], antiarrhythmic drugs [n = 53], or no antiarrhythmic treatment [n = 179]) on total mortality and mode of cardiac death was analyzed in 291 consecutive patients evaluated for cardiac transplantation between January 1986 and January 1995. There were 109 deaths (37.4%) (63 [21.6%] sudden, 40 [13.7%] nonsudden, and 6 [2.1%] noncardiac) during mean follow-up of 15 months (range, 1 to 118 months). Baseline clinical variables, medical therapies for heart failure, and actuarial rates of transplantation were similar between treatment groups. Kaplan-Meier sudden death rates were lowest in the ICD group, intermediate in the no antiarrhythmic treatment group, and highest in the drug treatment group throughout follow-up (12-month sudden death rates, 9.2%, 16.0%, and 34.7%, respectively; P = .004). Total mortality and nonsudden death rates did not differ. Cox proportional-hazards model revealed that antiarrhythmic drug treatment was associated with sudden death (relative risk, 2.1; 95% CI, 1.04 to 3.39; P = .04) and ICD was associated with nonsudden death (relative risk, 2.26; 95% CI, 1.12 to 4.62; P = .02).

CONCLUSIONS

Sudden death rates were lowest in patients treated with ICDs compared with drug treatment or no antiarrhythmic treatment. However, although ICDs reduced sudden death in selected high-risk patients with severe left ventricular dysfunction, the effect on long-term survival was limited, principally by high nonsudden death rates.

Antimyosin uptake and myofibrillarlysis in dilated cardiomyopathy

BACKGROUND

Although antimyosin scintigraphy detects myocyte necrosis associated with myocarditis, it has also been reported to yield positive results in a large number of patients with clinical dilated cardiomyopathy without histologic evidence of myocarditis. The question to be resolved is whether this discordance represents false-positive results of antimyosin scans or whether antimyosin scintigraphy more accurately identifies the presence of myocyte necrosis than does endomyocardial biopsy testing.

METHODS AND RESULTS

Forty patients with the acute onset of dilated cardiomyopathy (left ventricular ejection fraction < 45%; mean 27% +/- 11%) but no endomyocardial biopsy evidence of myocarditis, were identified from a consecutive series of 50 patients who had undergone indium 111 antimyosin antibody scintigraphy and endomyocardial biopsy for suspected myocarditis. The endomyocardial biopsy specimens were analyzed to identify features correlating with antimyosin uptake or improvement in left ventricular ejection fraction (LVEF) over time. Twenty-five patients showed left ventricular myocardial uptake of radiolabeled antimyosin antibody by both planar and tomographic imaging. The remaining 15 patients had no antimyosin uptake. Of the 25, 22 (88%) patients with positive findings on antimyosin scans had degenerated, myofibrillarlytic myocytes in their biopsy specimens. Of the 15 patients with negative findings on antimyosin scans, only 6 (40%) had similar myofibrillarlytic myocytes (chi 2 = 8.13; p < 0.0047). No other histological feature correlated with the antimyosin positivity. Stepwise multiple regression analysis was performed for identification of predictors of short-term improvement in LVEF. Patients with positive findings on antimyosin scans showed a trend toward improvement with time (F = 3.97; p > 0.05). None of the histologic features predicted improvement in the LVEF. However, the combination of positive findings on an antimyosin scan and myofibrillarlysis did correlate significantly with spontaneous improvement in ejection fraction (F = 4.53; 0.01; < p < 0.05).

CONCLUSIONS

This study identifies myofibrillarlysis as a common pathologic alteration in patients with recent onset of dilated cardiomyopathy and positive findings on antimyosin scan, who lack right ventricular biopsy evidence of myocarditis. Because myofibrillarlytic cell population may represent a histologic spectrum of viable to necrotic myocytes, it appears that antimyosin uptake detects necrotic myofibrillarlytic myocytes that are not identified by light microscopy.

Actinomycin D is an effective adjunctive immunosuppressive agent in recurrent cardiac allograft rejection

BACKGROUND

Actinomycin D is a potent cytotoxic agent which inhibits DNA transcription by DNA-dependent RNA polymerases and has previously been used as adjunctive immunosuppressive agent for refractory renal allograft rejection.

METHODS

To assess the efficacy of actinomycin D in cardiac allograft rejection, we studied seven patients with recurrent cellular or humoral rejection. All patients received intravenous actinomycin D 5 micrograms/kg every 6 weeks.

RESULTS

During the 6-months after initiation of actinomycin D treatment, the mean number of treated cellular or humoral rejection episodes per patient (0.14) and the mean number of International Society for Heart and Lung Transplantation grade 2 or higher endomyocardial biopsy specimens per patient (0.3) were lower compared with those observed during the 6-month pre-actinomycin D period (1.6 and 2.6, respectively). By 6 months after initiation of actinomycin D, all seven patients were receiving lower daily maintenance doses of corticosteroids. The mean total corticosteroid dose after actinomycin D administration per patient per month (615 +/- 177 mg) was significantly lower than the pre-actinomycin D dose (1012 +/- 347 mg; p = 0.019). No patient had significant adverse effects.

CONCLUSIONS

Actinomycin D is an effective immunosuppressive agent for prevention of recurrent cellular or humoral rejection after cardiac allograft rejection. The corticosteroid sparing effect of actinomycin D may be of particular benefit.

Preserved right ventricular ejection fraction predicts exercise capacity and survival in advanced heart failure

OBJECTIVES

This study was undertaken to determine which exercise and radionuclide ventriculographic variables predict prognosis in advanced heart failure.

BACKGROUND

Although cardiopulmonary exercise testing is frequently used to predict prognosis in patients with advanced heart failure, little is known about the prognostic significance of ventriculographic variables.

METHODS

The results of maximal symptom-limited cardiopulmonary exercise testing and first-pass radionuclide ventriculography in patients with advanced heart failure referred for evaluation for cardiac transplantation were analyzed.

RESULTS

Sixty-seven patients with advanced heart failure (mean [+/- SD]; age 51 +/- 10 years, New York Heart Association functional classes III (58%) and IV (18%); mean left ventricular ejection fraction 0.22 +/- 0.07) underwent simultaneous upright bicycle ergometric cardiopulmonary exercise testing and first-pass rest/exercise radionuclide ventriculography. Mean peak oxygen consumption (VO2) was 11.8 +/- 4.2 ml/kg per min, and mean peak age- and gender-adjusted percent predicted oxygen consumption (%VO2) was 38 +/- 11.9%. Univariate predictors of overall survival included right ventricular ejection fraction > or = 0.35 at rest and > or = 0.35 at exercise and %VO2 > or = 45% (all p < 0.05). In a multivariate proportional hazards survival model, right ventricular ejection fraction > or = 0.35 at exercise (p < 0.01) and %VO2 > or = 45% (p = 0.01) were selected as independent predictors of overall survival. Univariate predictors of event-free survival included right ventricular ejection fraction > or = 0.35 at rest (p = 0.01) and > or = 0.35 at exercise (p < 0.01), functional class II (p < 0.05) and %VO2 > or = 45% (p = 0.05). Right ventricular ejection fraction > or = 0.35 at exercise (p = 0.01) was the only independent predictor of event-free survival in a multivariate proportional hazards model. Cardiac index at rest, VO2, left ventricular ejection fraction at rest, and exercise-related increase or decrease > 0.05 in left or right ventricular ejection fraction were not predictive of overall or event-free survival in any univariate or multivariate analysis.

CONCLUSIONS

1) Right ventricular ejection fraction > or = 0.35 at rest and exercise is a more potent predictor of survival in advanced heart failure than VO2 or %VO2; 2) %VO2 rather than VO2 predicts survival in advanced heart failure; 3) neither %VO2 nor VO2 predicts survival to the combined end point of death or admission for inotropic or mechanical support in patients with advanced heart failure.

Evaluation of ischemic heart disease in potential lung transplant recipients

BACKGROUND

The prevalence of coronary artery disease in potential lung transplant recipients has not been extensively studied. Given the limited donor supply, a high degree of sensitivity for detecting occult disease is essential.

METHODS

This retrospective study examined both the clinical indications for coronary angiography and the extent of coronary arteriosclerotic disease in 105 consecutive potential lung transplant candidates.

RESULTS

Fifty-one patients (49%) underwent angiography to either exclude asymptomatic atherosclerosis (n = 46) or define the extent of known symptomatic ischemic heart disease (n = 5). The perceived risk of occult disease according to a semiquantitative coronary risk assessment score that included hypertension, hyperlipidemia, diabetes, smoking, a family history of coronary artery disease, and electrocardiographic or echocardiographic abnormalities influenced the decision to perform angiography: 4 of 44 patients (9%) with two or fewer risk factors underwent angiography versus 42 of 56 patients (75%) with more than two risk factors (p < or = 0.05). A higher risk factor score also correlated with angiographic evidence of coronary artery disease. In the 46 patients without symptoms who were studied, two hemodynamically significant but unsuspected coronary lesions were identified. Six other patients without symptoms had noncritical (< 50%) lesions. Among the five patients with angina or a prior myocardial infarction, coronary angiography showed either minimal atherosclerosis (n = 2) or non-life threatening anatomy (n = 3). Angiographic findings did not exclude any patient from transplant listing.

CONCLUSION

Coronary angiography appears most useful in patients without symptoms with multiple coronary risk factors and in a subset of patients who might otherwise be excluded from lung transplantation because of a history of symptomatic cardiovascular disease.

Hemodynamic effects of inhaled nitric oxide in heart failure

OBJECTIVES

This study was performed to assess the utility of inhaled nitric oxide as a selective pulmonary vasodilator in patients with severe chronic heart failure and to compare its hemodynamic effects with those of nitroprusside, a nonselective vasodilator.

BACKGROUND

Preoperative pulmonary vascular resistance is a predictor of right heart failure after heart transplantation. Non-selective vasodilators administered preoperatively to assess the reversibility of pulmonary vasoconstriction cause systemic hypotension, limiting their utility.

METHODS

Systemic and pulmonary hemodynamic measurement were made at baseline, during oxygen inhalation and with the addition of graded doses of inhaled nitric oxide or intravenous nitroprusside in 16 patients with New York Heart Association class III or IV heart failure referred for heart transplantation.

RESULTS

Pulmonary vascular resistance decreased to a greater extent with 80 ppm nitric oxide (mean +/- SEM 256 +/- 41 to 139 +/- 14 dynes.s.cm-5) than with the maximally tolerated dose of nitroprusside (264 +/- 49 to 169 +/- 30 dynes.s.cm-5, p < 0.05, nitric oxide vs. nitroprusside). Pulmonary capillary wedge pressure increased with 80 ppm nitric oxide (26 +/- 2 to 32 +/- 2 mm Hg, p < 0.05). Mean arterial pressure did not change with nitric oxide but decreased with nitroprusside. Seven of the 16 patients, including 1 patient who did not have an adequate decrease in pulmonary vascular resistance with nitroprusside but did with nitric oxide, have undergone successful heart transplantation.

CONCLUSIONS

Inhaled nitric oxide is a selective pulmonary vasodilator in patients with pulmonary hypertension due to left heart failure and may identify patients with reversible pulmonary vasoconstriction in whom agents such as nitroprusside cause systemic hypotension. Inhaled nitric oxide causes an increase in left ventricular filling pressure by an unknown mechanism.