The use of milrinone in pre-transplant assessment of patients with congestive heart failure and pulmonary hypertension

Levosimendan or milrinone for right ventricular inotropic treatment?-A secondary analysis of a randomized trial

BACKGROUND

The aim of the present study was to compare the effects of milrinone and levosimendan on right ventricular (RV) inotropy and lusitropy in patients after aortic valve replacement (AVR) for aortic stenosis, a procedure in which an abnormal postoperative RV function may be seen.

METHODS

In a prospective, blinded trial, 31 patients were randomized to receive either milrinone (0.4 and 0.8 µg/kg/min, n = 16) or levosimendan (0.1 and 0.2 µg/kg/min, n = 15) after AVR for aortic stenosis. RV performance, afterload (pulmonary arterial elastance), RV strain, systolic (SR-S) and early diastolic (SR-E) strain rate were measured by pulmonary artery thermodilution catheterization and transoesophageal two-dimensional speckle tracking echocardiography. To circumvent the indirect effects of inodilator-induced hemodynamic changes on RV systolic and diastolic deformation, pulmonary arterial elastance, central venous pressure and heart rate were maintained constant by atrial pacing, plasma volume expansion with colloids and phenylephrine-induced vasoconstriction during treatment with the inotropes.

RESULTS

A dose-dependent increase in stroke volume index and cardiac index by approximately 20% were seen with both agents at the highest doses, with no difference between groups (P = .792 and 0.744, respectively). In both groups, RV strain and SR-S dose-dependently increased by 20% and 15%-19%, respectively, at the highest doses (P = .742 and 0.259, respectively) with no difference between groups. SR-E improved by both agents 20%-24% at the highest dose with no difference between groups (P = .714).

CONCLUSIONS

The direct RV inotropic and lusitropic effects of levosimendan and milrinone were comparable at clinically relevant infusion rates.

Effect of Milrinone Infusion on Pulmonary Vasculature and Stroke Work Indices: A Single-Center Retrospective Analysis in 69 Patients Awaiting Cardiac Transplantation

BACKGROUND

Although milrinone infusion is reported to benefit left ventricular function in chronic left heart failure, few insights exist regarding its effects on pulmonary circulation and right ventricular function.

METHODS

We retrospectively reviewed right heart catheterization data at baseline and during continuous infusion of milrinone in 69 patients with advanced heart failure and analyzed the effects on ventricular stroke work indices, pulmonary vascular resistance and pulmonary arterial compliance.

RESULTS

Compared to baseline, milrinone infusion after a mean 58 ± 61 days improved mean left ventricular stroke work index (1540 ± 656 vs. 2079 ± 919 mmHg·mL/m², p = 0.0007) to a much greater extent than right ventricular stroke work index (616 ± 346 vs. 654 ± 332, p = 0.053); however, patients with below median stroke work indices experienced a significant improvement in both left and right ventricular stroke work performance. Overall, milrinone reduced left and right ventricular filling pressures and pulmonary and systemic vascular resistance by approximately 20%. Despite an increase in pulmonary artery capacitance (2.3 ± 1.6 to 3.0 ± 2.0, p = 0.013) and a reduction in pulmonary vascular resistance (3.8 ± 2.3 to 3.0 ± 1.7 Wood units), milrinone did not reduce the transpulmonary gradient (13 ± 7 vs. 12 ± 6 mmHg, p = 0.252), the pulmonary artery pulse pressure (25 ± 10 vs. 24 ± 10, p = 0.64) or the pulmonary artery diastolic to pulmonary capillary wedge gradient (2.0 ± 6.5 vs. 2.4 ± 6.0, p = 0.353).

CONCLUSION

Milrinone improved left ventricular stroke work indices to a greater extent than right ventricular stroke work indices and had beneficial effects on right ventricular net input impedance, predominantly via augmentation of left ventricular stroke volume and passive unloading of the pulmonary circuit. Patients who had the worst biventricular performance benefited the most from chronic milrinone infusion.

Effects of Single Drug and Combined Short-term Administration of Sildenafil, Pimobendan, and Nicorandil on Right Ventricular Function in Rats With Monocrotaline-induced Pulmonary Hypertension

This study was designed to assess the progression of pulmonary arterial hypertension (PAH) and the effectiveness of therapy using recently investigated echocardiographic parameters. PAH is characterized by the progressive elevation of pulmonary artery pressure and right ventricular hypertrophy and dysfunction, which ultimately results in right-sided heart failure and death. Echocardiography results and invasive measurements of right and left ventricular systolic pressures were compared after 3-week administrations of sildenafil (S group), pimobendan (P group), nicorandil (N group), and their combinations (SP and SPN groups) in male rats with monocrotaline (MCT)-induced pulmonary hypertension (M group) and without this condition (C group). The groups that received pimobendan alone and in combinations (SP and SPN groups) showed improvement in their echocardiographic parameters of systolic function. A significant improvement of diastolic function was achieved in the SPN group. Invasive measurements showed the most significant decreases of right ventricular systolic pressure in the N and SPN groups, and the use of pimobendan resulted in a comparatively low risk of adverse hemodynamic effects (left ventricular systolic pressure). Although our results suggested the attenuation of PAH severity in all treatment groups, PAH could not be reversed.

Inotropes do not increase mortality in advanced heart failure

Inotrope use is one of the most controversial topics in the management of heart failure. While the heart failure community utilizes them and recognizes the state of inotrope dependency, retrospective analyses and registry data have overwhelmingly suggested high mortality, which is logically to be expected given the advanced disease states of those requiring their use. Currently, there is a relative paucity of randomized control trials due to the ethical dilemma of creating control groups by withholding inotropes from patients who require them. Nonetheless, results of such trials have been mixed. Many were also performed with agents no longer in use, on patients without an indication for inotropes, or at a time before automatic cardio-defibrillators were recommended for primary prevention. Thus, their results may not be generalizable to current clinical practice. In this review, we discuss current indications for inotrope use, specifically dobutamine and milrinone, depicting their mechanisms of action, delineating their patterns of use in clinical practice, defining the state of inotrope dependency, and ultimately examining the literature to ascertain whether evidence is sufficient to support the current view that these agents increase mortality in patients with heart failure. Our conclusion is that the evidence is insufficient to link inotropes and increased mortality in low output heart failure.

Comparison of drugs for pulmonary hypertension reversibility testing: A meta-analysis

Multiple drugs are used for reversibility testing of pulmonary hypertension (PH) in advanced heart failure (HF), especially in the process of heart transplant evaluation. Effects of these drugs were never systematically compared. The aim of this meta-analysis was to compare hemodynamic effects of different drugs. We identified 20 prospective studies reporting hemodynamic variables before and after acute pharmacologic testing for PH reversibility in patients with advanced HF. The data from individual studies were grouped by an outcome measure and analyzed. A mixed model meta-analysis was performed using SAS to give weighted mean effect of pre- and post-test change and inverse variance. The mean effects were weighted by the published sample size. Prostacyclin, inhaled or intravenous, and prostaglandin E1 (PGE1) had the most potent effect on pulmonary vascular resistance (PVR). Sodium nitroprusside and nitroglycerin decreased pulmonary capillary wedge pressure (PCWP), and mean pulmonary arterial pressure (MPAP) better than other drugs. Sildenafil provided overall good hemodynamic outcomes but was not the strongest drug with regard to any particular outcome. PCWP, MPAP, and systolic pulmonary arterial pressure respond better to nitroglycerin and sodium nitroprusside than to other drugs in the setting of reversibility testing. Prostacyclin and PGE1 are superior to other drugs in their acute effects on PVR.

Impact of pulmonary vascular resistances in heart transplantation for congenital heart disease

Congenital heart disease is one of the major diagnoses in pediatric heart transplantation recipients of all age groups. Assessment of pulmonary vascular resistance in these patients prior to transplantation is crucial to determine their candidacy, however, it is frequently inaccurate because of their abnormal anatomy and physiology. This problem places them at significant risk for pulmonary hypertension and right ventricular failure post transplantation. The pathophysiology of pulmonary vascular disease in children with congenital heart disease depends on their pulmonary blood flow patterns, systemic ventricle function, as well as semilunar valves and atrioventricular valves structure and function. In our review we analyze the pathophysiology of pulmonary vascular disease in children with congenital heart disease and end-stage heart failure, and outline the state of the art pre-transplantation medical and surgical management to achieve reverse remodeling of the pulmonary vasculature by using pulmonary vasodilators and mechanical circulatory support.

Early right ventriculo-arterial uncoupling in borderline pulmonary hypertension on experimental heart failure

Pulmonary hypertension on heart failure (HF) limits exercise capacity and survival probably because of associated right ventricular (RV) failure. This study investigated the mechanisms of RV function adaptation to early pulmonary hypertension in experimental HF. Seven weeks of rapid ventricular pacing in six dogs induced a HF characterized by cardiomegaly and decreased left ventricular ejection fraction. Compared with eight control dogs, pulmonary hypertension was borderline, with a mean pulmonary artery pressure increased to only 23 ± 2 (means ± SE) mmHg. However, the pulmonary vascular impedance spectrum was globally shifted to higher pressures, with an increase in 0 Hz impedance (resistance) to 662 ± 69 vs. 455 ± 41 dynes·cm−5·m2 in controls ( P < 0.01) and in characteristic impedance to 183 ± 20 vs. 104 ± 7 dynes·cm−5·m2 in controls ( P < 0.01). There was no change in RV end-systolic elastance (Ees), but arterial elastance (Ea) was increased to 1.8 ± 0.3 vs. 0.9 ± 0.1 mmHg/ml in controls so that RV-arterial coupling defined by the Ees-to-Ea ratio (Ees/Ea) was decreased to 0.8 ± 0.1 vs. 1.5 ± 0.1 in controls ( P < 0.01). Inhaled nitric oxide, 40 ppm or 5 μg·kg−1·min−1 nitroprusside iv, did not affect Ees/Ea. Fifty milligrams (iv) of milrinone increased Ees/Ea to 1.6 ± 0.2 by an isolated increase in Ees. We conclude that overpacing-induced HF is accompanied by a borderline pulmonary hypertension but profound RV-arterial uncoupling explained by the failure of RV systolic function to adapt combined effects of increased pulmonary arterial resistance and elastance.

Effects on pre- and posttransplant pulmonary hemodynamics in patients with continuous-flow left ventricular assist devices

OBJECTIVE

Pulsatile left ventricular assist devices have been shown to effectively reduce pulmonary hypertension in patients with end-stage heart failure. However, it remains to be seen whether newer continuous-flow left ventricular assist devices have a similar effect on pulmonary hypertension. The objective of this study was to determine whether the HeartMate II (Thoratec Corp, Pleasanton, Calif), a continuous-flow left ventricular assist device, is effective in improving pulmonary hemodynamics in the period after left ventricular assist device support and posttransplant.

METHODS

Fifty patients with end-stage heart failure underwent HeartMate II left ventricular assist device placement as a bridge to transplant. We evaluated their pulmonary hemodynamics with right-sided heart catheterization at baseline, after left ventricular assist device placement, and after heart transplant.

RESULTS

The mean age of patients was 53.7 +/- 13.5 years. Ischemic etiology was present in 60% of the patients. After left ventricular assist device placement (mean duration, 135 +/- 60 days), mean systolic and diastolic pulmonary artery pressures decreased significantly from a baseline of 55.2 +/- 13.4 mm Hg and 27.3 +/- 6.8 mm Hg, respectively, to 35.9 +/- 10.8 mm Hg and 15.8 +/- 6.5 mm Hg, respectively (P < .001). Similarly, mean pulmonary vascular resistance decreased significantly from a baseline of 3.6 +/- 1.9 Woods units to 2.1 +/- 0.8 Woods units (P < .001). Posttransplant pulmonary hemodynamics also remained within normal limits, even in patients with previously severe pulmonary hypertension.

CONCLUSION

Continuous-flow left ventricular assist devices effectively improve pulmonary hemodynamics associated with end-stage heart failure. Moreover, pulmonary hemodynamics remain within normal limits in the posttransplant period, even in patients with severe pulmonary hypertension. Therefore, adequate left ventricular decompression achieved with newer left ventricular assist devices can reverse significant pulmonary hypertension in patients with end-stage heart failure, making them eligible for cardiac transplantation.

Pulmonary hypertension in heart failure

BACKGROUND

Pulmonary hypertension occurs in 60% to 80% of patients with heart failure and is associated with high morbidity and mortality.

METHODS AND RESULTS

Pulmonary artery pressure correlates with increased left ventricular end-diastolic pressure. Therefore, pulmonary hypertension is a common feature of heart failure with preserved as well as reduced systolic function. Pulmonary hypertension is partially reversible with normalization of cardiac filling pressures. Pulmonary vasculature remodeling and vasoconstriction create a second component, which does not reverse immediately, but has been shown to improve with vasoactive drugs and especially with left ventricular assist devices.

CONCLUSION

Many drugs used for idiopathic pulmonary arterial hypertension are being considered as treatment options for heart failure-related pulmonary hypertension. This is of particular significance in the heart transplant population. Randomized clinical trials with interventions targeting heart failure patients with elevated pulmonary artery pressure would be justified.

Pulmonary hypertension secondary to left ventricular systolic dysfunction: contemporary diagnosis and management

Pulmonary hypertension secondary to left ventricular systolic dysfunction is often a poor prognostic marker in chronic heart failure. In this article, we review evidence supporting modern strategies addressing pulmonary hypertension in patients with left ventricular systolic dysfunction, including right-sided heart catheterization with vasoreactivity testing and subsequent parenteral, oral, and inhaled therapy. We delineate a diagnostic approach to secondary pulmonary hypertension and outline evidence-based therapeutic strategies for management in acute and chronic heart failure.

Evaluation of pulmonary vascular response to inhaled iloprost in heart transplant candidates with pulmonary venous hypertension

OBJECTIVE

Chronic left-heart failure is often associated with the development of pulmonary venous hypertension. In heart transplant candidates this is of great significance because the healthy donor heart has to compensate the increased right-ventricular afterload. Right-ventricular dysfunction is still responsible for 19% of all early deaths after orthotopic heart transplantation. Careful preoperative assessment of pulmonary vascular resistance by right-heart catheterization is essential. Reversibility testing is generally carried out to clarify therapeutic options for the post-transplant period. The objective of this case series is to report our institutional experience with inhaled iloprost compared to the common used oxygen/nitroglycerin method for reversibility testing.

METHODS

Right-heart catheterization was performed in 23 patients with severely impaired left-ventricular function (EF < or = 25%, pVO2 < or = 14 ml/kg/min, NYHA III or IV) with combined pulmonary venous hypertension (TPG > 12 mm Hg and or PVR > 250 dyn x s x cm(-5)). An intraindividual comparison was performed between of the hemodynamic effect with oxygen/nitroglycerin s.l. and inhaled iloprost.

RESULTS

The transpulmonary gradient fell significantly from an initial 16 mm Hg to 13 mm Hg on oxygen/nitroglycerin s.l. compared to 10 mm Hg on inhaled iloprost. Pulmonary vascular resistance fell significantly from an initial 344 dyn x s x cm(-5) to 270 dyn x s x cm(-5) on oxygen/nitroglycerin s.l. compared to 209 dyn x s x cm(-5) on inhaled iloprost. On inhaled iloprost a moderate systemic effect was noticed.

CONCLUSION

In heart transplant candidates with pulmonary venous hypertension reversibility testing with inhalation of iloprost is a save method and significantly more effective than the combination of inhaled oxygen plus nitroglycerin s.l.

Reversible pulmonary hypertension in heart transplant candidates: to transplant or not to transplant

BACKGROUND

Pulmonary hypertension (PHT), defined as a pulmonary vascular resistance (PVR) greater than 2.5 Wood units [WU] and(or) transpulmonary gradient (TPG) greater than 12 mm Hg, is a risk factor for mortality in cardiac transplantation due to elevated postoperative right heart failure. Orthotopic heart transplantation is possible if PVR could be reversed below 2.5 WU and TPG below 12 mm Hg. We show the Muenster experience from the last 10 years.

METHODS

From April 1996 to December 2005 all cardiac transplant recipients separated into patients with and without PHT were included. All patients with PHT had successful reduction (PVR < or = 2.5 WU and TPG < or = 12 mm Hg) using prostaglandin I2 or E1. Posttransplant early and late mortality and incidence of right heart failure were studied.

RESULTS

Two hundred seventeen patients were included in this study. Of these, 168 had normal pulmonary pressures (non-PHT group), 49 (22.6%) had reversible PHT (rev-PHT group). Mean PVR was 1.6 +/- 1.1 WU vs 2.1 +/- 1.1 WU (p < 0.01; non-PHT vs rev-PHT) and mean TPG 8.0 +/- 1.9 mm Hg vs 10.6 +/- 4.1 mm Hg (p = not significant [NS]). Thirty-day survival after orthotopic cardiac transplantation was 85% vs 78% (p = 0.150) and 10 year survival 63% vs 61% (p = NS). Right heart failure during the first 30 days after transplantation occurred in 27% in the non-PHT group and in 64% in the rev-PHT group (p = 0.035). However, in patients transplanted after 2001 it did not appear.

CONCLUSIONS

Cardiac transplant candidates with reversible PHT have still significantly elevated pulmonary pressures compared with patients without PHT. Despite a significantly higher risk of right heart failure, long-term survival after orthotopic cardiac transplantation was not affected.

Selective pulmonary vasodilation with inhaled aerosolized milrinone in heart transplant candidates

PURPOSE

Selective pulmonary vasodilation is an advantageous method for testing the responsiveness of the pulmonary vasculature of heart transplant candidates. A pilot study was under-taken to test the hypothesis that inhaled aerosolized milrinone may cause selective pulmonary vasodilation.

METHODS

18 consecutive male heart transplant candidates with either dilated or ischemic cardiomyopathy were included in this open clinical study. Nine of the patients had significant pulmonary hypertension with a mean pulmonary arterial pressure > 30 mmHg. After baseline measurements, 2 mg of milrinone was administered by ultrasonic nebulization. Pulmonary and systemic hemodynamics were measured ten, 30, and 60 min after inhalation.

RESULTS

After inhalation for ten minutes, milrinone induced a significant reduction of mean pulmonary arterial pressure (32.7 +/- 9.1 vs 37.7 +/- 7.5 mmHg, P = 0.01), pulmonary vascular resistance index (296 +/- 150 vs 396 +/- 151 dyn.sec(-1).cm(-5).m(2), P = 0.02) and transpulmonary gradient (10.6 +/- 5.5 vs 15 +/- 4.9, P = 0.01) only in patients with significant pulmonary hypertension. There was no significant effect on mean arterial pressure or systemic vascular resistance at any time after inhalation in either group. Furthermore, there was no influence on extravascular lung water or intrathoracic blood volume.

CONCLUSIONS

We conclude that inhaled aerosolized milrinone for a short period selectively dilates the pulmonary vasculature in heart transplant candidates with elevated pulmonary arterial pressure, without producing systemic side effects. Further comparative studies are necessary to evaluate possible advantages of milrinone compared to other inhaled vasodilators.

Extracorporeal Membrane Oxygenation for Perioperative Cardiac Allograft Failure

The utility of mechanical support in pretransplant stabilization and postcardiotomy shock is well established, but its use in perioperative cardiac allograft failure (PCAGF) rescue has not been well documented. Ventricular assist devices (VADs) have been applied to PCAGF rescue with acceptable results. However, studies have not described the results of using extracorporeal membrane oxygenation (ECMO) in PCAGF. We evaluated the outcome of PCAGF rescue with ECMO. A retrospective review of 204 consecutive heart transplants revealed 19 cases of PCAGF requiring ECMO rescue. Donor-, surgery- and ECMO-related variables were evaluated for association with operative mortality, success of weaning, and survival rate. Transplant recipients included 14 males and 5 females with median age of 44.2 years. Weaning rate was 84.2% and survival rate was 52.6%, with duration of ECMO support 157 +/- 129 hours. Long ischemic time is a PCAGF risk factor (206.8 +/- 96.1 minutes vs. 158.3 +/- 60.8 minutes in non-PCAGF, p < 0.05). PCAGF etiology included primary graft failure (n = 7); right heart failure secondary to pulmonary hypertension, coagulopathy/intraoperative hemorrhage (n = 7); and sepsis (n = 2). Compared with data from VAD-supported PCAGF, ECMO had a better weaning and graft survival rates (p < 0.05). ECMO is another choice for PCAGF rescue. It has an acceptable survival rate and may be considered instead of VADs as a first-line rescue for PCAGF.

Combined Administration of Intravenous Dipyridamole and Inhaled Nitric Oxide to Assess Reversibility of Pulmonary Arterial Hypertension in Potential Cardiac Transplant Recipients

BACKGROUND

Irreversible, severe pulmonary hypertension (PH) can produce right heart failure and early mortality after cardiac transplantation. We hypothesized that dipyridamole, an inhibitor of Type 5 phosphodiesterase, would augment the ability of inhaled nitric oxide (NO) to identify reversibility of PH.

METHODS

In 9 patients with congestive heart failure (CHF) and severe PH who were breathing 100% oxygen during right heart catheterization, we administered inhaled NO (80 ppm) alone and in combination with intravenous dipyridamole (0.2-mg/kg bolus, with an infusion of 0.0375 mg/kg/min).

RESULTS

Compared with breathing oxygen alone, NO inhalation decreased pulmonary artery pressure and pulmonary vascular resistance (PVR) (by 10 +/- 4% and 26 +/- 12% [mean +/- SEM], respectively; both p < 0.05). The combination of NO and dipyridamole reduced PVR (43 +/- 7%; p < 0.05) to a greater extent than did administration of NO alone, and increased the duration of pulmonary vasodilation produced by NO inhalation. Combined administration of inhaled NO and intravenous dipyridamole increased cardiac index (by 23 +/- 10%) and reduced SVR (by 19 +/- 6%, both p < 0.05) without changing systemic arterial pressure. NO inhalation reduced PVR to <200 dyne x s/cm5 in 3 of 7 patients who had a PVR of >200 dyne x s/cm5 when breathing oxygen alone, whereas the combination of NO and dipyridamole decreased PVR to <200 dyne.s/cm(5) in 2 additional patients.

CONCLUSIONS

Intravenous dipyridamole augments and prolongs the pulmonary vasodilator effects of inhaled NO in CHF patients with severe PH and, when administered in combination with NO inhalation, can identify PH reversibility in potential cardiac transplant recipients in whom a pulmonary vasodilator response to inhalation of NO alone is not observed.

Pre-transplant reversible pulmonary hypertension predicts higher risk for mortality after cardiac transplantation

BACKGROUND

Pre-transplant fixed pulmonary hypertension is associated with higher post-transplant mortality. In this study, we assessed the significance of pre-transplant reversible pulmonary hypertension in patients undergoing cardiac transplantation.

METHODS

Overall, we studied 182 patients with baseline normal pulmonary pressures or reversible pulmonary hypertension, defined as a decrease in pulmonary vascular resistance (PVR) to < or =2.5 Wood units (WU), who underwent cardiac transplantation. Multiple recipient and donor characteristics were assessed to identify independent predictors of mortality.

RESULTS

The average duration of follow-up was 42 +/- 28 months. Forty patients (22%) died during the follow-up period. Baseline hemodynamics for alive vs dead patients were as follows: pulmonary artery systolic (PAS) 42 +/- 15 vs 52 +/- 15 mm Hg; PA diastolic 21 +/- 9 vs 25 +/- 9 mm Hg; PA mean 28 +/- 11 vs 35 +/- 10 mm Hg; transpulmonary gradient (TPG) 9 +/- 4 vs 11 +/- 7 mm Hg (all p < 0.05); total pulmonary resistance 7.7 +/- 4.8 vs 8.8 +/- 3.2 WU (p = 0.08); and PVR 2.3 +/- 1.5 vs 2.9 +/- 1.6 WU (p = 0.06). In an unadjusted analysis, patients with PAS >50 mm Hg had a higher risk of death (odds ratio [OR] 5.96, 95% confidence interval [CI] 1.46 to 19.84 as compared with PAS < or =30 mm Hg). There was no significant difference in survival among patients with baseline PVR <2.5, 2.5 to 4.0 or >4.0 WU, but patients with TPG > or =16 had a higher risk of mortality (OR 4.93, 95% CI 1.84 to 13.17). PAS pressure was an independent predictor of mortality (OR 1.04, 95% CI 1.02 to 1.06). Recipient body mass index, history of sternotomy; and donor ischemic time were the other independent predictors of mortality.

CONCLUSION

Pre-transplant pulmonary hypertension, even when reversible to a PVR of < or =2.5 WU, is associated with a higher mortality post-transplant.

A prospective study of continuous intravenous milrinone therapy for status IB patients awaiting heart transplant at home

BACKGROUND

We performed a prospective study to determine the feasibility and safety of continuous intravenous milrinone therapy administered at home in patients listed as Status IB for heart transplant.

METHODS

Patients who were Status IB could participate if they met specific criteria including an optimal dose of milrinone < or =0.5 microg/kg/min, presence of an implantable cardioverter-defibrillator (ICD), and no other serious comorbidity. The primary end-point of the study was survival to transplant. Hospitalizations, quality of life and cost comparisons were assessed.

RESULTS

From May 1999 through October 2002, a total of 60 patients (51 men, 9 women), aged 55.5 +/- 8.4 years, entered the study. Before milrinone therapy, cardiac index was 1.98 +/- 0.66 liters/min/m2 and peak oxygen consumption was 11.4 +/- 2.6 ml/kg/min. Mean time in the study was 160.1 +/- 151.8 days. Fifty-three patients (88.3%) underwent heart transplant. There were only 2 deaths during the study. There were 89 hospital admissions in 46 patients over the 43-month follow-up period; 58 of these admissions were for heart failure. There were 6 episodes of ICD firing for ventricular tachycardia. Quality-of-life measures in a sub-group of patients significantly improved 1 month after discharge. Substantial estimated cost savings occurred.

CONCLUSIONS

Continuous intravenous milrinone therapy can be safely administered at home in selected patients with advanced heart failure who are listed for transplant. This strategy may be an acceptable alternative to prolonged hospitalization for patients dependent on continuous inotropic support. Re-hospitalization is to be expected. An implantable cardioverter-defibrillator should be present due to the incidence of ventricular tachycardia.

Improvement of apparently fixed pulmonary hypertension with cardiac resynchronization therapy

Many patients with advanced heart failure are ineligible for cardiac transplantation because of fixed pulmonary arterial hypertension. Cardiac resynchronization therapy, by stimulating the right atrium, and right and left ventricles, is a new therapy that effectively palliates symptoms in patients with heart failure. Cardiac resynchronization therapy increases cardiac output and decreases pulmonary capillary wedge pressure, thus partially reversing hemodynamic abnormalities that lead to secondary pulmonary hypertension in many heart failure patients. We describe a patient whose previously fixed pulmonary hypertension improved to the point that she was once again considered eligible for cardiac transplantation.

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

BACKGROUND

Heart transplantation is the most effective treatment for well-selected patients with endstage heart failure. Unfortunately, transplant candidates with pulmonary hypertension (PHT) are often not considered for heart transplantation. This study was performed to assess the value of prostaglandin E(1) (PG-E(1)) for reduction of PHT and to predict the postoperative outcome, compared to patients without PHT.

PATIENTS AND METHODS

We studied a group of 151 consecutive heart transplant candidates using right heart catheterization. In patients with PHT (pulmonary vascular resistance, PVR> or =2.5 Wood-Units (WU) and/or transpulmonary gradient (TPG)> or =12 mmHg) a short-term treatment protocol with PG-E(1) was performed, to achieve PVR<2.5 WU and TPG<12 mmHg.

RESULTS

61 patients (40%) had PHT according to our criteria. Reduction of PHT was successful in 71% of patients (n=43), of these, 18 patients underwent cardiac transplantation and the 1-year mortality rate was 22% (n=4). The 1-year mortality rate in transplanted patients without PHT was 14% (n=3). There was no statistical difference in survival between the PHT and the non-PHT group. Outcome in patients without heart transplantation was similar in both groups, except for patients with non-reducible PHT (1-year mortality 50%).

CONCLUSIONS

Our study demonstrates the efficacy and safety of PG-E(1) in lowering PHT in heart transplant candidates, as well as the need for aggressive evaluation and treatment in these patients. Patients with reversible PHT have comparable post-transplant outcomes and no tendency to higher acute right ventricular failure.

Reversibility of Medically Unresponsive Pulmonary Hypertension with Nesiritide in a Cardiac Transplant Recipient

Pulmonary hypertension unresponsive to medical therapy is considered by most centers to be a contraindication for orthotopic cardiac transplantation. This article describes a patient with unresponsive severe pulmonary hypertension who, despite a combination of maximal doses of dobutamine, milrinone, and nitroprusside infusion, responded to nesiritide (Natrecor) infusion with improvement in pulmonary hemodynamics. The patient was considered a high risk for transplantation because of significant pulmonary hypertension in spite of maximum oral therapy and continuous intravenous milrinone. Severe irreversible pulmonary hypertension persisted with a combination of dobutamine, milrinone, and nitroprusside, with pulmonary artery pressure (PA) of 88/44 mm Hg, a transpulmonary gradient (TPG) of 27, and pulmonary vascular resistance (PVR) of 5.79 Wood units. Upon addition of nesiritide, within 24 hours, there was a sustained decrease in PA to 47/30, TPG of 15, and PVR of 3.75 Wood units. The patient underwent successful left ventricular assist device placement soon after nesiritide infusion demonstrated reversibility of pulmonary hypertension. He subsequently underwent uneventful orthotopic cardiac transplantation and has done well with normal right heart pressures. This case illustrates that addition of nesiritide to standard therapy can reverse significant unresponsive pulmonary hypertension and make a patient eligible for left ventricular assist device and orthotopic cardiac transplantation.

Mechanical support for the failing cardiac allograft: a single-center experience

BACKGROUND

Mechanical support for pre-transplant stabilization is established, but its use in peri-operative graft failure (PGF) has not been well documented. With liberal acceptance criteria being used to enlarge the donor pool, an increased incidence of graft failure might be expected. We evaluated the incidence and outcome of PGF at our institution.

METHODS

A retrospective review of 462 consecutive adult heart transplants performed between January 1993 and December 1999 revealed 20 cases of PGF. Donor-, surgery- and device-related variables were evaluated for association with operative mortality, survival and successful device weaning.

RESULTS

Transplant recipients included 17 men and 3 women, median age 56.5 years (20 to 66 years). PGF etiology included primary graft failure (n = 9); right heart failure (RHF) secondary to pulmonary hypertension, coagulopathy/intra-operative hemorrhage or sepsis (n = 9); and hyperacute rejection (n = 2). Device types included RVAD (n = 11), LVAD (n = 4), BIVAD (n = 3) and IABP (n = 2). The wean rate was 45%. Duration of device support ranged from 2 to 965 hours. Early ventricular recovery (within 96 hours) was associated with significantly better 30-day and 2-year survival. Weaned patients had an 88% 30-day and 67% 2-year survival, whereas the overall survival rate was 79% at 2 years (p = not significant).

CONCLUSIONS

Early ventricular recovery is an important predictor of successful weaning and survival. In view of the prohibitive mortality associated with PGF and the dismal prognosis with re-transplantation, we advocate aggressive use of mechanical assistance for PGF, with an acceptable survival benefit.

Factors determining the duration of tracheal intubation in cardiac surgery: a single-centre sequential patient audit

BACKGROUND AND OBJECTIVE

The study was designed to identify those factors associated with early tracheal extubation following cardiac surgery. Previous studies have tended to concentrate on surgery for coronary artery bypass or on other selected cohorts.

METHODS

Sequential cohort analysis of 296 unselected adult cardiac surgery patients was performed over 3 months.

RESULTS

In total, 39% of all patients were extubated within 6 h, 89% within 24 h and 95% within 48 h. Delayed extubation (>6 h after surgery) appeared unrelated to age, gender, body mass index, a previous pattern of angina or myocardial infarction, diabetes, preoperative atrial fibrillation, and preoperative cardiovascular assessment, as well as other factors. Delayed tracheal extubation was associated with poor left ventricular, renal and pulmonary function, a high Euroscore, as well as the type, duration and urgency of surgery. Early extubation (<6 h) was not associated with a reduced length of stay in either the intensive care unit or in hospital compared with patients who were extubated between 6 and 24 h. In these groups, it is presumed that organizational and not clinical factors appear to be responsible for a delay in discharge from intensive care. Patients who were extubated after 24 h had a longer duration of hospital stay and a greater incidence of postoperative complications. Postoperative complications were not adversely affected by early tracheal extubation.

CONCLUSIONS

In an unselected sequential cohort, both patient- and surgery-specific factors may be influential in determining the duration of postoperative ventilation of the lungs following cardiac surgery. In view of the changing nature of the surgical population, regular re-evaluation is useful in reassessing performance.

Injection pain of rocuronium and vecuronium is evoked by direct activation of nociceptive nerve endings

BACKGROUND AND OBJECTIVE

Rocuronium and, to a lesser extent, vecuronium can induce burning sensations associated with withdrawal reactions during administration. Dermal microdialysis in human and electrophysiological recordings of nociceptors in mouse skin were used to elucidate the underlying mechanisms of pain induction.

METHODS

Microdialysis catheters were inserted intradermally into the forearm of 10 volunteers and were perfused with two different concentrations of rocuronium and vecuronium (1 and 10 mg mL(-1)) or a control. Dialysis samples were taken every 15 min and analysed for protein, histamine, tryptase and bradykinin content. Pain intensity was rated on a numerical scale of 0-10. In a parallel design, activation of cutaneous nociceptors was assessed directly in a skin-nerve in vitro preparation of the mouse hind paw. The receptive fields of identified single C-nociceptors (n = 12) were superfused with rocuronium or vecuronium solutions (10 mg mL(-1)) at physiological pH.

RESULTS

In accordance with clinical observations, microdialysis of rocuronium (10 mg mL(-1)) induced sharp burning pain (NRS 4.1 +/- 1.8), whereas vecuronium given in the usual clinical concentration (1 mg mL(-1)) induced only minor pain sensations (NRS 0.6 +/- 1.3). At equimolar concentrations, pain sensation and concomitant mediator release evoked by both drugs were similar. No correlations were found between pain rating and mediator release. In the in vitro preparation, C-fibres showed a consistent excitatory response with rapid onset after stimulation with vecuronium as well as rocuronium (differences not significant).

CONCLUSIONS

The algogenic effect of aminosteroidal neuromuscular blocking drugs can be attributed to a direct activation of C-nociceptors.

Anaesthetic strategies to reduce perioperative blood loss in paediatric surgery

In adults, a number of measures to reduce perioperative blood loss have been established. These techniques serve to reduce patients' exposure to homologous blood. Most adults are concerned with this issue especially since many patients became infected with human immunodeficiency virus (HIV) during the 1980s through exposure to blood components. While blood-saving strategies are widely used in adults, they are mostly neglected in infants. However, it is these young patients with their whole life in front of them who, it could be argued, would benefit especially from any potentially avoidable infection (HIV, hepatitis, etc.) or immunological complications. In infants and small children, these blood-sparing techniques may not be as effective as in adults and technical limitations may prevent their application. However, some of these measures can be used and may serve to prevent or reduce exposure to homologous blood. In the following review, blood-saving techniques established in adults are described and their applicability for paediatric patients discussed.

Effects of propofol on the systolic and diastolic performance of the postischaemic, reperfused myocardium in rabbits

BACKGROUND AND OBJECTIVE

The effect of propofol on myocardial dysfunction during ischaemia and reperfusion is controversial yet important because of its frequent use in cardiac anaesthesia. Although animal studies suggest a free radical-scavenging potential, the cardioprotective properties of propofol have not been demonstrated consistently in vivo. Previous studies focused on systolic function while diastolic function may be a more sensitive marker of ischaemic injury. The main aim was to document the effect of propofol on diastolic function in isolated, blood perfused rabbit hearts subjected to moderate global ischaemia and reperfusion.

METHODS

Propofol 168 micromol L(-1), or the equivalent of its vehicle, Intralipid, was administered to 34 paced parabiotic Langendorff blood-perfused isolated rabbit hearts before and after 30 min of global normothermic ischaemia. Recovery of systolic function was quantified with the maximum rate of rise of left ventricular pressure. Diastolic performance was assessed using the time constant of the decline in left ventricular pressure (tau) and chamber stiffness (VdP/dV at 12 mmHg).

RESULTS

Recovery of systolic function during reperfusion was comparable in the two groups. There was no difference in left ventricular pressure between the two groups at any time during the experiments. Chamber stiffness increased significantly during ischaemia and reperfusion in the control group (from 34 +/- 9 to 54 +/- 8 mmHg during ischaemia, and 43 +/- 5 mmHg after 30 min reperfusion; mean +/-95% confidence interval) but not in the propofol-treated group (29 +/- 5, 36 +/- 8 and 30 +/- 8 at baseline, ischaemia and 30 min reperfusion, respectively).

CONCLUSIONS

Propofol has no protective effect on active relaxation or on systolic function in the present model, but it reduces ischaemic and postischaemic chamber stiffness.

Effects of bupivacaine used with sevoflurane on the rhythm and contractility in the isolated rat heart

BACKGROUND AND OBJECTIVE

The effects of sevoflurane on bupivacaine cardiotoxicity are mainly attributed to systemic effects. The purpose of this study was to investigate the direct myocardial effects of sevoflurane on bupivacaine toxicity.

METHODS

Hearts of 30 Wistar albino rats were isolated and mounted on a Langendorff apparatus perfused by modified Tyrode solution. Experimental groups were: a sevoflurane group (Group S, n = 10)--following baseline and 20 min (Stage 1) recordings, sevoflurane was added in doses of 1.4% (1 MAC) and 2.8% (2 MAC). In the two bupivacaine groups, bupivacaine 5 micromol (Group B5, n = 10) and bupivacaine 10 micromol (Group B10, n = 10) was added to the solution at Stage 1, and sevoflurane was added to the system as in Group S. Haemodynamic variables, i.e. heart rate, PR interval, QRS duration, left ventricular systolic pressure, contractility (+dp/dtmax), relaxation, time to reach peak systolic pressure, change in left ventricular diastolic pressure from baseline, and rate-pressure product were recorded.

RESULTS

In Group S, there was no change in cardiac rhythm. In bupivacaine groups, severe rhythm disturbances occurred and both the PR intervals and QRS complexes were prolonged significantly. All contractility variables deteriorated and the rate-pressure product decreased by 67-90% with the addition of bupivacaine. In all groups, 2 MAC sevoflurane lowered +dp/dtmax further.

CONCLUSIONS

Sevoflurane does not have any untoward effect on bupivacaine-induced cardiotoxicity in clinically relevant doses in the isolated rat heart.

Effect of the neuronal nitric oxide synthase inhibitor 7-nitroindazole on the righting reflex ED50 and minimum alveolar concentration during sevoflurane anaesthesia in rats

BACKGROUND AND OBJECTIVE

The aim was to determine the effect of acute and chronic administration of 7-nitroindazole, a selective neuronal nitric oxide synthase inhibitor, on the righting reflex ED50 and the minimum alveolar concentration during sevoflurane anaesthesia in rats.

METHODS

7-Nitroindazole was acutely (0, 50 and 100 mg kg(-1)) and chronically (0 and 150 mg kg(-1) day(-1), 4 days) administered to rats. After the preparation, the minimum alveolar concentration and the righting reflex ED50 were measured. The concentration of cGMP in the brain, cerebellum and spinal cord was also measured.

RESULTS

Acute administration reduced the minimum alveolar concentration (50 mg kg(-1), 58.8% (95% CI: 50.3-67.3%) of the baseline value, P < 0.01; 100 mg kg(-1), 55.8 (46.9-64.7), P < 0.01) and the righting reflex ED50 (50 mg kg(-1), 27.2 (17.2-37.2), P < 0.01; 100 mg kg(-1), 14.3 (6.6-22.0), P < 0.01). Chronic administration did not reduce the minimum alveolar concentration; however, it reduced the righting reflex ED50 (65.3 (52.9-77.7), P < 0.01). Overall, the reduction in minimum alveolar concentration in the acute and chronic protocol did not correlate with that of the righting reflex ED50. 7-Nitroindazole (100 mg kg(-1), acute) reduced the cGMP concentration within the cerebellum by 55.4%; however, it did not decrease concentrations in the brain or spinal cord.

CONCLUSIONS

Different mechanisms are responsible for the observed alterations to the minimum alveolar concentration and the righting reflex ED50 following treatment with 7-nitroindazole. The nitric oxide-cGMP pathway might play a less important role in the determination of minimum alveolar concentration than the righting reflex ED50.

Suprascapular nerve block or a piroxicam patch for shoulder tip pain after day case laparoscopic surgery

BACKGROUND AND OBJECTIVE

The reported incidence of shoulder tip pain following laparoscopic surgery varies from 35 to 63%. This study evaluated the analgesic efficacy of either performing a prophylactic suprascapular nerve block with bupivacaine or applying a piroxicam patch to the skin over both shoulders for the relief of shoulder tip pain after laparoscopy.

METHODS

Sixty healthy informed female patients were randomly assigned to one of three groups: (a) a control group (n = 20), no treatment; (b) a suprascapular nerve block group (n = 20) in which a bilateral suprascapular nerve block was performed before induction of anaesthesia with 5 mL 0.5% bupivacaine with epinephrine; and (c) a piroxicam patch group (n = 20) in which a 48 mg piroxicam patch on the skin of each shoulder was applied before induction of anaesthesia. All patients received a total intravenous anaesthesia technique with propofol, fentanyl and vecuronium. Shoulder tip and wound pain were recorded on a visual analogue pain scale at five time intervals for 24 h after surgery.

RESULTS

A total of 80% of patients in the control group, 75% in the suprascapular nerve block group and 45% in the piroxicam patch group complained of shoulder tip pain during the recording period (P < 0.05). The scores for shoulder tip pain in the piroxicam patch group were significantly lower compared with the control group at 3, 6 and 12 h, and compared with the suprascapular nerve block group at 6 and 12 h. The need for analgesics was also significantly lower in the piroxicam patch group compared with the other two groups.

CONCLUSIONS

Prophylactic piroxicam patches are effective and safe for the relief of shoulder tip pain after laparoscopy. Bilateral suprascapular nerve block is not effective in this setting.

Treatment of hiccup during general anaesthesia or sedation: a qualitative systematic review

BACKGROUND AND OBJECTIVE

Acute hiccup is a minor complication that can occur during sedation or general anaesthesia. The disorder can disturb the surgical field, might interfere with lung ventilation or could hamper diagnostic procedures. The objective was to perform a systematic search for interventions aimed at treating hiccup occurring during anaesthesia or sedation.

METHODS

A systematic search for reports describing interventions to treat hiccup in conjunction with anaesthesia was carried out (MEDLINE, EMBASE, Cochrane-Library, manual screening of reference lists and review articles, up to December 2001). Search terms were 'hiccup', 'singultus' or 'hiccough'.

RESULTS

Twenty-six reports involving approximately 581 patients focused on hiccup remedies in the anaesthesia setting. Only one report was substantiated by a randomized controlled trial. This investigated methylphenidate 10 mg intravenously in 51 patients, which did not show a beneficial effect compared with placebo. Hiccup was a self-limiting phenomenon. Case series and case reports focused on various systemically applied drugs in 12 reports, stimulating techniques (e.g. pharyngeal stimulation) in seven, topical applied remedies (e.g. intranasal ice-cold water) in four, and ventilation techniques (e.g. continuous positive pressure ventilation) in two.

CONCLUSIONS

A large variety of interventions have been proposed for the treatment of hiccup during anaesthesia and sedation. However, perioperative treatment is still based on empirical findings and no treatment is 'evidence-based'. Thus, no valid recommendations for the treatment of hiccup can be derived. Uncontrolled observations are inadequate to establish treatment efficacy.

Pharmacokinetics and pharmacodynamics of the new propofol prodrug GPI 15715 in rats

BACKGROUND AND OBJECTIVE

We studied the pharmacokinetics and pharmacodynamics of GPI 15715 (Aquavan injection), a new water-soluble prodrug metabolized to propofol by hydrolysis.

METHODS

Nine adult male Sprague-Dawley rats (398 +/- 31 g) received a bolus dose of 40 mg GPI 15715. The plasma concentrations of GPI 15715 and propofol were determined from arterial blood samples, and the pharmacokinetics of both compounds were investigated using compartment models whereby the elimination from the central compartment of GPI 15715 was used as drug input for the central compartment of propofol. Pharmacodynamics were assessed using the median frequency of the EEG power spectrum.

RESULTS

A maximum propofol concentration of 7.1 +/- 1.7 microg mL(-1) was reached 3.7 +/- 0.2 min after bolus administration. Pharmacokinetics were best described by two-compartment models. GPI 15715 showed a short half-life (2.9 +/- 0.2 and 23.9 +/- 9.9 min), an elimination rate constant of 0.18 +/- 0.01 min(-1) and a central volume of distribution of 0.25 +/- 0.02 L kg(-1). For propofol, the half-life was 1.9 +/- 0.1 and 45 +/- 7 min, the elimination rate constant was 0.15 +/- 0.02 min(-1) and the central volume of distribution was 2.3 +/- 0.6 L kg(-1). The maximum effect on the electroencephalogram (EEG)--EEG suppression for >4 s--occurred 6.5 +/- 1.2 min after bolus administration and baseline values of the EEG median frequency were regained 30 min later. The EEG effect could be described by a sigmoid Emax model including an effect compartment (E0 = 16.9 +/- 7.9 Hz, EC50 = 2.6 +/- 0.8 microg mL(-1), ke0 = 0.35 +/- 0.04 min(-1)).

CONCLUSIONS

Compared with known propofol formulations, propofol from GPI 15715 showed a longer half-life, an increased volume of distribution, a delayed onset, a sustained duration of action and a greater potency with respect to concentration.

High-affinity block of voltage-operated rat IIA neuronal sodium channels by 2,6 di-tert-butylphenol, a propofol analogue

BACKGROUND AND OBJECTIVE

Propofol is a phenol derivative (2,6 di-isopropylphenol) with a unique effect profile including activating effects on GABA(A) and blocking effects on voltage-operated sodium channels. If the substituents in the 2- and the 6-positions are replaced by tert-butyl groups, the resulting phenol derivative, 2,6 di-tert-butylphenol, despite being a close structural propofol analogue, completely lacks GABA(A) receptor effects. The aim of this in vitro study was to investigate the effects of 2,6 di-tert-butylphenol on voltage-operated neuronal sodium channels in order to determine whether and, if so, how these structural changes alter the sodium channel-blocking effect seen with propofol.

METHODS

Whole-cell sodium inward currents through heterologously expressed rat type IIA sodium channels were recorded in the absence and presence of definite concentrations of 2,6 di-tert-butylphenol and propofol.

RESULTS

When applied at concentrations > or = 30 micromol, 2,6 di-tert-butylphenol completely and irreversibly blocked sodium inward currents. The blockade equilibrium time was about 2 min. A partial washout was possible only if the application was stopped before the equilibrium of the blockade was achieved.

CONCLUSIONS

2,6 Di-tert-butylphenol exerts a high-affinity block of neuronal sodium channels. Apparently, the slight structural differences of 2,6 di-tert-butylphenol in comparison with propofol--which account for the lack of GABA(A) receptor effects--enhance its voltage-operated sodium channel-blocking effects. As 2,6 di-tert-butylphenol is much more potent than most sodium channel blockers in clinical use, it might be of interest in the development of local anaesthetics.

Effects of rolipram, pimobendan and zaprinast on ischaemia-induced dysrhythmias and on ventricular cyclic nucleotide content in the anaesthetized rat

BACKGROUND AND OBJECTIVE

This study was designed to compare the haemodynamic, electrophysiological and pharmacodynamic effects of three selective inhibitors of the different isoenzyme forms of phosphodiesterase (PDE) on ischaemia-induced dysrhythmias in the anaesthetized rat. The drugs used were pimobendan, a selective PDE III inhibitor, rolipram, a selective PDE IV inhibitor, and zaprinast, a selective PDE V inhibitor.

METHODS

The coronary artery was occluded 15 min after commencing drug administration, and myocardial ischaemia was maintained for 30 min during which the heart rate and mean arterial pressure were recorded. cAMP and cGMP were determined by radioimmunoassay.

RESULTS

Pretreatment with rolipram decreased the duration of ventricular tachycardia without any change in the incidences of dysrhythmias or the mortality rate. This drug did not modify ventricular content of adenosine 3',5'-cyclic monophosphate (cAMP) or guanosine 3',5'-cyclic monophosphate (cGMP). Pimobendan (1 mg kg(-1) + 0.1 mg kg(-1) min) decreased the duration of ventricular tachycardia. This dose of pimobendan and zaprinast (1 mg kg(-1) + 0.1 mg kg(-1) min(-1)) increased the incidence rate of ventricular fibrillation following coronary artery ligation and the mortality rate. Moreover, both drugs increased cGMP in the ventricle.

CONCLUSIONS

The results demonstrated that pimobendan and zaprinast increased the incidence of dysrhythmias and the mortality rate, which was accompanied by an increase in the ventricular content of cGMP. Rolipram decreased the duration of ventricular tachycardia without a change in the cyclic nucleotide content or in the mortality rate.

Urapidil reduces elevated pulmonary vascular resistance in patients before heart transplantation

BACKGROUND

Elevated pulmonary vascular resistance is a major limitation for heart transplantation. Urapidil is a centrally and peripherally acting anti-hypertensive drug, able to decrease elevated pulmonary vascular resistance in patients with either chronic obstructive pulmonary disease or heart failure. Urapidil is available as an oral or intravenous drug. In this study, we evaluated the possible beneficial effects of intravenous urapidil in patients with reversible, elevated pulmonary vascular resistance who were scheduled for heart transplantation.

METHODS

After approval by the Ethics Committee and written consent, 22 consecutive patients with end-stage heart failure and history of pulmonary vascular resistance >3 Wood units were enrolled into an open, prospective study. Using a (right ventricular ejection fraction) REF-Swan-Ganz catheter, hemodynamics were determined during administration of nitric oxide, and before and after 3 repeated intravenous applications of 10 mg urapidil. The treatment goal was reduction of pulmonary vascular resistance by at least 30%.

RESULTS

Twenty-two patients were included to obtain complete data for 14 patients. Eight patients were not treated with urapidil: 7 patients had normal pulmonary vascular resistance at baseline, and 1 patient experienced moderate pulmonary edema before the study began. Two patients did not reach the treatment goal. In patients who responded to urapidil, the following hemodynamic changes were observed: decreased pulmonary vascular resistance (-48%), decreased transpulmonary gradient (20.0 to 13.7 mm Hg), decreased mean pulmonary arterial pressure (40 to 31 mm Hg), decreased systemic vascular resistance (-27%), mean arterial pressure (80 to 72 mm Hg), and increased right heart ejection fraction (21% to 27%). Heart rate remained unchanged.

CONCLUSIONS

Intravenous urapidil lowered elevated pulmonary vascular resistance in patients before heart transplantation. In comparison with other vasodilative drugs, the major benefit of urapidil is its oral formulation.

Intravenous milrinone in cardiac surgery

Phosphodiesterase inhibitors including milrinone produce positive inotropic effects by slowing the hydrolysis of cyclic adenosine monophosphate in the myocardium. With a loading dose of 50 microg/kg followed by an infusion of 0.5 microg x kg(-1) x min(-1), milrinone increases stroke volume index and left ventricular velocity of circumferential fiber shortening after weaning from cardiopulmonary bypass. Milrinone has potential for the treatment and prevention of internal mammary artery spasm because of its vasodilative effect, which is similar to that of papaverine, and is a potent pulmonary vasodilator for patients with right ventricular dysfunction and pulmonary vasoconstriction. Low-dose milrinone may have antiinflammatory properties and potentially can improve splanchnic perfusion.

Impact of current management practices on early and late death in more than 500 consecutive cardiac transplant recipients

OBJECTIVE

To study risk factors for early and late death after heart transplantation in the current era.

SUMMARY BACKGROUND DATA

The current cardiac transplant population differs from earlier periods in that an increasing number of sicker patients, such as those with ventricular assist device (LVAD) support, prior cardiac allotransplantation, and pulmonary hypertension, are undergoing transplantation. In addition, sensitized patients constitute a greater proportion of the transplanted population. Emphasis has been placed on therapies to prevent early graft loss, such as the use of nitric oxide and improved immunosuppression, in addition to newer therapies.

METHODS

Five hundred thirty-six patients undergoing heart transplantation between 1993 and 1999 at a single center were evaluated (464 adults and 72 children; 109 had received prior LVAD support and 24 underwent retransplantation). The mean patient age at transplantation was 44.9 years. Logistic regression and Cox proportional hazard models were used to evaluate the following risk factors on survival: donor and recipient demographics, ischemic time, LVAD, retransplantation, pretransplant pulmonary vascular resistance, and immunologic variables (ABO, HLA matching, and pretransplant anti-HLA antibodies).

RESULTS

The rate of early death (less than 30 days) was 8.5% in adults and 8.8% in children. The actuarial survival rate of the 536 patients was 83%, 77%, and 71% at 1, 3, and 5 years, respectively, by Kaplan Meier analysis. Risk factors adversely affecting survival included the year of transplant, donor age, and donor-recipient gender mismatching. Neither early nor late death was influenced by elevated pulmonary vascular resistance, sensitization, prior LVAD support, or prior cardiac allotransplantation.

CONCLUSIONS

Previously identified risk factors did not adversely affect short- or long-term survival of heart transplant recipients in the current era. The steady improvement in survival during this period argues that advances in transplantation have offset the increasing acuity of transplant recipients.