Peter Rickenbacher

Expression of Inducible Nitric Oxide Synthase in Human Heart Failure

BACKGROUND There is increasing evidence that alterations in nitric oxide synthesis are of pathophysiological importance in heart failure. A number of studies have shown altered nitric oxide production by the endothelial constitutive isoform of nitric oxide synthase (NOS), but there is very little information on the role of the inducible isoform. METHODS AND RESULTS We analyzed inducible NOS (iNOS) expression in ventricular myocardium taken from 11 control subjects (who had died suddenly from noncardiac causes), from 10 donor hearts before implantation, and from 51 patients with heart failure (24 with dilated cardiomyopathy [DCM], 17 with ischemic heart disease [IHD], and 10 with valvular heart disease [VHD]). Reverse transcription-polymerase chain reaction was used to confirm the presence of intact mRNA and to detect expression of iNOS and atrial natriuretic peptide (ANP). ANP was used as a molecular phenotypic marker of ventricular failure. iNOS was expressed in 36 of 51 biopsies (71%) from patients with heart failure and in none of the control patients (P<.0001). iNOS expression could also be detected in 50% of the donor hearts. All samples that expressed iNOS also expressed ANP. iNOS gene expression occurred in 67% of patients with DCM, 59% of patients with IHD, and 100% of patients with VHD. To determine whether iNOS protein was expressed in failing ventricles, immunohistochemistry was performed on three donor hearts and nine failing hearts with iNOS mRNA expression. Staining for iNOS was almost undetectable in the donor myocardium and in control sections, but all failing hearts showed diffuse cytoplasmic staining in cardiac myocytes. Expression of iNOS could be observed in all four chambers. Western blot analysis with the same primary antibody showed a specific positive band for iNOS protein in the heart failure specimens; minimal iNOS protein expression was seen in donor heart samples. CONCLUSIONS iNOS expression occurs in failing human cardiac myocytes and may be involved in the pathophysiology of DCM, IHD, and VHD.

Effects of Controlled-Release Metoprolol on Total Mortality, Hospitalizations, and Well-being in Patients with Heart Failure: The Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF)

Åke Hjalmarson, MD, PhD Sidney Goldstein, MD Björn Fagerberg, MD, PhD Hans Wedel, PhD Finn Waagstein, MD, PhD John Kjekshus, MD, PhD John Wikstrand, MD, PhD Dia El Allaf, MD Jirı́ Vı́tovec, MD, PhD Jan Aldershvile, MD, PhD Matti Halinen, MD, PhD Rainer Dietz, MD Karl-Ludwig Neuhaus, MD András Jánosi, MD, DSc Gudmundur Thorgeirsson, MD, PhD Peter H. J. M. Dunselman, MD, PhD Lars Gullestad, MD Jerzy Kuch, MD Johan Herlitz, MD, PhD Peter Rickenbacher, MD Stephen Ball, MD, PhD Stephen Gottlieb, MD Prakash Deedwania, MD for the MERIT-HF Study Group

Prognostic Importance of Intimal Thickness as Measured by Intracoronary Ultrasound After Cardiac Transplantation

BACKGROUND Although intracoronary ultrasound (ICUS) has been validated for the early detection of transplant coronary artery disease (TxCAD), the prognostic importance of findings detected by this new imaging technique is unknown. METHODS AND RESULTS This study examined the relation of clinical outcome in 145 heart transplant recipients (mean age, 45.1 +/- 11.1 years) with the amount of intimal thickness measured by ICUS during routine annual coronary angiography 1 to 10 years (mean, 3.1 +/- 2.2 years) after transplantation. From published autopsy data, a mean intimal thickness of > 0.3 mm was considered significant. During a mean follow-up time of 48.2 +/- 10.2 months, 23 deaths (12 cardiac) occurred, and 6 patients required retransplantation. Angiographic TxCAD developed in 22 of 125 patients (17.6%) in the subgroup with normal angiograms at the time of ICUS and a follow-up annual angiographic study. In the total population and the subgroup, mean intimal thicknesses of > 0.3 and < or = 0.3 mm, respectively, were associated with significantly inferior 4-year actuarial overall survival (73% versus 96%, P = .005; 72% versus 92%, P = .05), cardiac survival (79% versus 96%, P = .005; 80% versus 98%, P = .04), and freedom from cardiac death and retransplantation (74% versus 98%, P < .0001; 70% versus 96%, P = .001). In addition, ICUS predicted freedom from development of subsequent angiographic TxCAD in the subgroup that was initially normal (26% versus 72%, P = .02). A mean intimal thickness by ICUS of > 0.3 mm was associated with inferior clinical outcome regardless of the presence of angiographic TxCAD and predicted the development of subsequent angiographic TxCAD. Despite significantly longer duration after transplantation, higher rejection incidence, and lower average daily cyclosporine dose, none of these covariates were independent risk factors for outcome. CONCLUSIONS These findings confirm the prognostic importance of mean intimal thickening of > 0.3 mm in heart transplant recipients and suggest that these patients should be candidates for early interventional strategies.

Induction of Nitric Oxide Synthase in the Human Cardiac Allograft Is Associated With Contractile Dysfunction of the Left Ventricle

BACKGROUND The mechanisms underlying cardiac contractile dysfunction after transplantation remain poorly defined. Previous work has revealed that inducible nitric oxide synthase (iNOS) is expressed in the rat heterotopic cardiac allograft during rejection; resultant overproduction of nitric oxide (NO) might cause cardiac contractile dysfunction via the negative inotropic and cytotoxic actions of NO. In this investigation, we tested the hypothesis that induction of iNOS may occur and be associated with cardiac allograft contractile dysfunction in humans. METHODS AND RESULTS We prospectively studied 16 patients in the first year after cardiac transplantation at the time of serial surveillance endomyocardial biopsy. Clinical data, the results of biopsy histology, and echocardiographic and Doppler evaluation of left ventricular systolic and diastolic function were recorded. Total RNA was extracted from biopsy specimens, and mRNA for beta-actin, detected by reverse transcription-polymerase chain reaction (RT-PCR) using human specific primers, was used as a constitutive gene control; iNOS mRNA was similarly detected by RT-PCR using human specific primers. iNOS protein was detected in biopsy frozen sections by immunofluorescence. Myocardial cGMP was measured by radioimmunoassay, and serum nitrogen oxide levels (NOx = NO2 + NO3) were measured by chemiluminescence. iNOS mRNA was detected in allograft myocardium at some point in each patient and in 59 of 123 biopsies (48%) overall. In individual patients, iNOS mRNA expression was episodic and time dependent; the frequency of expression was highest during the first 180 days after transplant (P = .0006). iNOS protein associated with iNOS mRNA was detected by immunofluorescence in cardiac myocytes. iNOS mRNA expression was not related to the ISHLT histological grade of rejection or to serum levels of NOx but was associated with increased levels of myocardial cGMP (P = .01) and with both systolic (P = .024) and diastolic (P = .006) left ventricular contractile dysfunction measured by echocardiography and Doppler. CONCLUSIONS These data support a relation between iNOS mRNA expression and contractile dysfunction in the human cardiac allograft.

Incidence and severity of transplant coronary artery disease early and up to 15 years after transplantation as detected by intravascular ultrasound

OBJECTIVES The purpose of this study was to quantify the severity of transplant coronary artery disease and to assess lesion characteristics early and up to 15 years after heart transplantation by using intracoronary ultrasound. BACKGROUND Intravascular ultrasound has the ability to measure the components of the arterial wall and has been shown to be a sensitive method for detection of transplant coronary artery disease. METHODS A total of 304 intracoronary ultrasound studies were performed in 174 heart transplant recipients at baseline and up to 15 (mean 3.3 +/- 0.2) years after transplantation. Mean intimal thickness and an intimal index were calculated, and lesion characteristics (eccentricity, calcification) were assessed for all coronary sites imaged (mean 3.0 +/- 0.1 sites/study). The Stanford classification was used to grade lesion severity. RESULTS Compared with findings in patients studied at baseline (< 2 months after transplantation, n = 50), mean intimal thickness (0.09 +/- 0.02 vs. 0.16 +/- 0.02 mm, p < 0.01), intimal index (0.07 +/- 0.01 vs. 0.14 +/- 0.02, p < 0.01) and mean severity class (1.5 +/- 0.2 vs. 2.3 +/- 0.2, p < 0.01) were significantly higher at year 1 (n = 52) after transplantation. Thereafter, all three variables further increased over time and reached highest values between years 5 and 15. Calcification of lesions was detected in 2% to 12% of studies up to 5 years after transplantation, with a significant increase to 24% at years 6 to 10 (p < 0.05). CONCLUSIONS Severity of transplant coronary artery disease appeared to progress with time after transplantation in this cross-sectional study. This characteristic was most prominent during the 1st 2 years after transplantation, whereas calcification of plaques occurred to a significant extent only later in the process. These data may serve as a reference for comparison of intravascular ultrasound findings in other studies of patients with transplant coronary artery disease.

Incidence of myocarditis in peripartum cardiomyopathy

Peripartum cardiomyopathy (PC), an uncommon cause of peripartum heart failure, is defined as a cardiomyopathy presenting in the last trimester of pregnancy or the first 6 months postpartum, without evidence of preexisting cardiovascular disease. The etiology of PC and idiopathic dilated cardiomyopathy (IDC) remains uncertain. Several reports have addressed possible differences in clinical presentation and prognosis between these groups. A relatively high incidence of myocarditis has been recently reported in patients with PC, raising the possibility that this may represent a distinct difference between this condition and IDC. A retrospective review of endomyocardial biopsy specimens from 34 patients fulfilling the criteria for a diagnosis of PC was therefore performed to further evaluate this finding. Results indicate a lower incidence of myocarditis (8.8%, 3 of 34) than that reported in other studies. This incidence was comparable to that found in an age- and sex-matched control population undergoing transplantation for IDC (9.1%, 2 of 22). Factors that may influence the diverse range in the reported incidence of myocarditis are discussed.

Long-term benefit–risk balance of drug-eluting vs. bare-metal stents in daily practice: does stent diameter matter? Three-year follow-up of BASKET

AIMS To assess the long-term benefit-risk ratio of drug-eluting (DES) vs. bare-metal stents (BMS) relative to stent size. METHODS AND RESULTS All 826 consecutive BASKET (BAsel Stent Kosten-Effektivitäts Trial) patients randomized 2:1 to DES vs. BMS were followed after 3 years. Data were analysed separately for patients with small stents (<3.0 mm vessel/<4.0 mm bypass grafts, n = 268) vs. only large stents (> or =3.0 mm native vessels, n = 558). Clinical events were related to stent thrombosis. Three-year clinical target-vessel revascularization rates remained borderline reduced after DES [9.9 vs. 13.9% (BMS), P = 0.07], particularly in patients with small stents (10.7 vs. 19.8%, P = 0.03; large stents: 9.5 vs. 11.5%, P = 0.44). Cardiac death/myocardial infarction (MI) rates (12.7 vs. 10.0%, P = 0.30) were similar, however, death/MI beyond 6 months was higher after DES [9.1 vs. 3.8% (BMS), P = 0.009], mainly due to increased late death/MI in patients with large stents (9.7 vs. 3.1%, P = 0.006). The results paralleled findings for stent thrombosis. CONCLUSION The clinical benefit of DES was maintained at no overall increased risk of death or death/MI up to 3 years. However, death/MI rates were increased in DES vs. BMS patients beyond 6 months, particularly in patients with large stents, paralleling findings for stent thrombosis. Thus, stent size seems to influence the 3-year benefit-risk ratio after DES implantation.

CORONARY ARTERY INTIMAL THICKENING IN THE TRANSPLANTED HEART: An In Vivo Intracoronary Ultrasound Study of Immunologic and Metabolic Risk Factors

This study examined the hypothesis that immunologic factors are the major correlates of coronary artery intimal thickening and luminal stenosis. The study population included 116 adult heart transplant recipients with a mean age of 44.7 +/- 12.0 years (89 men and 27 women) undergoing annual coronary angiography and intracoronary ultrasound 3.4 +/- 2.7 (range, 1.0-14.6) years after transplantation. Mean intimal thickness was obtained from several distinct sites along the left anterior descending and/or left circumflex coronary artery by intracoronary ultrasound. Coronary artery stenosis defined by angiography was classified as mild (< 30% luminal stenosis), moderate (> or = 30-70% luminal stenosis), or severe (> 70% luminal stenosis or diffuse pruning of distal vessels). Prevalence of any transplant coronary artery disease (TxCAD) was 85% by intracoronary ultrasound and 15% by angiography. By multiple regression analysis, only average fasting plasma triglyceride level (P < 0.006) and average weight (P < 0.007) were significantly correlated with severity of intimal thickening (R = 0.54, P < 0.0001). Donor age (P < 0.006) and average fasting plasma triglyceride level (P < 0.009) were significantly correlated with stenosis by angiography. Correlation of multiple immunologic and metabolic factors with intimal thickness by univariate analysis suggests a multifactorial etiology for TxCAD. Among the multiple univariate correlates of TxCAD, higher fasting plasma triglyceride levels and body weight are the only independent correlates of TxCAD. The absence of acute rejection as an independent predictor of intimal thickening suggests that mechanisms beyond those mediating typical cellular rejection should be targeted for advancing our understanding of Tx-CAD.

Pre-clinical diabetic cardiomyopathy: prevalence, screening, and outcome.

Diabetic cardiomyopathy, characterized by left ventricular (LV) dysfunction and LV hypertrophy independent of myocardial ischaemia and hypertension, could contribute to the increased life‐time risk of congestive heart failure seen in patients with diabetes. We assessed prospectively the prevalence, effectiveness of screening methods [brain natriuretic peptide (BNP) and C‐reactive protein in combination with clinical parameters], and outcome of pre‐clinical diabetic cardiomyopathy.

Transplant candidates with severe left ventricular dysfunction managed with medical treatment: Characteristics and survival

OBJECTIVES This study sought to assess the clinical characteristics and survival of patients with symptomatic heart failure who were referred as potential heart transplant candidates, but were selected for medical management. BACKGROUND Patients with severe left ventricular dysfunction referred for heart transplantation may be considered too well to be placed immediately on an active waiting transplant list. The clinical characteristics of this patient group and their survival have not been well defined. These patients represent a unique group that are characterized by comparatively low age and freedom from significant comorbid conditions. METHODS We studied 116 consecutive patients with symptomatic heart failure, severe left ventricular dysfunction (left ventricular ejection fraction 20 +/- 7% [mean +/- SD]) and duration of symptoms >1 month referred for heart transplantation, who were acceptable candidates for the procedure but who were not listed for transplantation because of relative clinical stability. These patients were followed up closely on optimal medical therapy. A variety of baseline clinical, hemodynamic and exercise variables were assessed to define this patient group and used to predict cardiac death and requirement later for heart transplantation. RESULTS During a mean follow-up period of 25.0 +/- 14.8 months (follow-up 99% complete), there were eight cardiac deaths (7%) (seven sudden, one acute myocardial infarction). Only nine patients (8%) were listed for heart transplantation. Actuarial 1- and 4-year cardiac survival rates were 98 +/- 1% and 84 +/- 7% (mean +/- SE), respectively, and freedom from listing for transplantation was 95 +/- 2% and 84 +/- 7% (mean +/- SE), respectively. Patients were mainly in New York Heart Association functional class II or III and had a preserved cardiac index (2.4 liters/min.m2), pulmonary capillary wedge pressure of 16 +/- 9 mm Hg (mean +/- SD) and maximal oxygen consumption of 17.4 +/- 4.3 ml/min per kg (mean +/- SD). By logistic regression analysis, there was no predictor for cardiac death. Longer duration of heart failure (p = 0.013) and mean pulmonary artery (p < 0.05) and pulmonary systolic (p = 0.014) and diastolic (p < 0.05) pressures correlated significantly with listing for heart transplantation by univariate logistic regression. By multivariate logistic regression, only pulmonary artery systolic pressure (p < 0.004) and duration of heart failure (p < 0.015) remained as predictors for need for later transplantation. CONCLUSIONS In the current treatment era, prognosis is favorable in a definable group of transplant candidates despite severe left ventricular dysfunction. This patient group can be identified after intensive medical therapy by stable symptoms, a relatively high maximal oxygen uptake at peak exercise and a preserved cardiac output.