Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) methods for the therapeutic drug monitoring of cytotoxic anticancer drugs: An update

In the era of precision medicine, there is increasing evidence that conventional cytotoxic agents may be suitable candidates for therapeutic drug monitoring (TDM)- guided drug dosage adjustments and patient's tailored personalization of non-selective chemotherapies. To that end, many liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) assays have been developed for the quantification of conventional cytotoxic anticancer chemotherapies, that have been comprehensively and critically reviewed. The use of stable isotopically labelled internal standards (IS) of cytotoxic drugs was strikingly uncommon, accounting for only 48 % of the methods found, although their use could possible to suitably circumvent patients' samples matrix effects variability. Furthermore, this approach would increase the reliability of cytotoxic drug quantification in highly multi-mediated cancer patients with complex fluctuating pathophysiological and clinical conditions. LC-MS/MS assays can accommodate multiplexed analyses of cytotoxic drugs with optimal selectivity and specificity as well as short analytical times and, when using stable-isotopically labelled IS for quantification, provide concentrations measurements with a high degree of certainty. However, there are still organisational, pharmacological, and medical constraints to tackle before TDM of cytotoxic drugs can be more largely adopted in the clinics for contributing to our ever-lasting quest to improve cancer treatment outcomes.

Pharmacokinetic Modeling and Simulation with Pharmacogenetic Insights Support the Relevance of Therapeutic Drug Monitoring for Myeloablative Busulfan Dosing in Adult HSCT

Therapeutic drug monitoring (TDM) of busulfan (Bu) is well-established in pediatric hematopoietic stem cell transplantation (HSCT), but its use in adults is limited due to a lack of clear recommendations and scarcity of evidence regarding its utility. GSTA1 promoter variants are reported to affect Bu clearance in both adults and pediatric patients. This study aimed to evaluate the value of preemptive genotyping GSTA1 and body composition (obesity) in individualizing Bu dosing in adults, through pharmacokinetic (PK) modeling and simulations. A population pharmacokinetic (PopPK) model was developed and validated with data from 60 adults who underwent HSCT. Simulations assessed different dosing scenarios based on body size metrics and GSTA1 genotypes. Due to the limited number of obese patients in the cohort, the effect of obesity on Bu pharmacokinetics (PK) was evaluated in silico using a physiologically-based pharmacokinetic (PBPK) model and relevant virtual populations from Simcyp software. Patients with at least 1 GSTA1*B haplotype had 17% lower clearance on average. PopPK simulations indicated that adjusting doses based on genotype increased the probability of achieving the target exposure (3.7 to 5.5 mg.h/L) from 53% to 60 % in GSTA1*A homozygous patients, and from 50% to 61% in *B carriers. Still, Approximately 40% of patients would not achieve this therapeutic window without TDM. A 2-sample optimal design was validated for routine model-based Bu first dose AUC0-∞ estimation, and the model was implemented in the Tucuxi user-friendly TDM software. PBPK simulations confirmed body surface area-based doses of 29 to 31 mg/m2/6h as the most appropriate, regardless of obesity status. This study emphasizes the importance of individualized Bu dosing strategies in adults to achieve therapeutic targets. Preemptive genotyping alone may not have a significant clinical impact, and routine TDM may be necessary for optimal transplantation outcomes.

Severe acute kidney injury in a patient with renal artery stenosis of a single-functioning kidney: A case report of rapid normalisation of the renal function after percutaneous transluminal angioplasty with stent placement

Revascularisation of renal arterial stenosis in acute settings, such as uncontrolled arterial hypertension, flash pulmonary oedema and/or acute renal failure, has shown controversial results in observational and prospective studies. Current guidelines do not recommend revascularisation in the occurrence of renal failure as revascularisation and best medical treatment have shown similar long-term outcomes on renal function. We describe a case of acute degradation of the renal function (with oligo-anuria and a peak creatinine of 462 µmol/L) after the re-introduction of an angiotensin-II receptor blocker (irbesartan) in a 66-year-old Caucasian diabetic male patient with bilateral renal stenosis and a right-sided single-functioning kidney, with a rapid improvement of the renal function which normalized 5 days after percutaneous angioplasty and stenting of the right renal artery.

Effect of pharmacokinetics and pharmacogenomics in adults with allogeneic hematopoietic cell transplantation conditioned with Busulfan

Busulfan (Bu) combined with cyclophosphamide (Cy) is commonly used as a myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation (allo-HCT). There is inter-individual variability of Bu pharmacokinetics (PK) and hence in toxicity and efficacy. The introduction of therapeutic drug monitoring (TDM) of Bu has decreased toxicity of the regimen. Hepatic metabolism of Bu is mediated through Glutathione-S-Transferases (GSTs), mainly GSTA1. Patients with GSTA1*A variants are considered normal metabolizers and GSTA1*B corresponds to poor metabolism, defined by nucleotide changes at -52 or -69 locus in GSTA1 promoter region. The aim of the study was to explore the correlation between GSTA1 polymorphisms and Bu-PK in 60 adult patients receiving an allo-HCT in the BuCyBu clinical study (ClinicalTrials.gov I, ID NCT01779882) comparing the sequence BuCy to CyBu. DNA samples prior to conditioning were genotyped for candidate variants at -52 (rs3957356) and -69 (rs3957357) loci in the GSTA1 promoter. Thirty-three % of patients were GSTA1*A*A, 49% GSTA1*A*B and 18% GSTA1*B*B. In GSTA1*A*A patients, median Bu-AUC was 3.6 ± 0.7 mg*h/L, in GSTA1*A*B 4.5 ± 1.6 and in GSTA1*B*B 4.9 ± 1.4 (AUC 35% higher than GSTA1*A*A, p = 0.03), with a similar significant correlation with Bu-clearance (p = 0.04). The correlation between GSTA1 polymorphism and AUC remained significant in multivariate linear regression analysis. There was a trend for lower non-relapse mortality (NRM) in patients with low AUC. We could not demonstrate a correlation between GSTA1 polymorphisms and NRM, acute graft-versus-host disease (aGvHD) in this small cohort, but there is a trend of higher aGvHD incidence in GSTA1*B*B patients.

Impaired photoprotection in Phaeodactylum tricornutum KEA3 mutants reveals the proton regulatory circuit of diatoms light acclimation

Diatoms are successful phytoplankton clades able to acclimate to changing environmental conditions, including e.g. variable light intensity. Diatoms are outstanding at dissipating light energy exceeding the maximum photosynthetic electron transfer (PET) capacity via the nonphotochemical quenching (NPQ) process. While the molecular effectors of NPQ as well as the involvement of the proton motive force (PMF) in its regulation are known, the regulators of the PET/PMF relationship remain unidentified in diatoms. We generated mutants of the H⁺ /K⁺ antiporter KEA3 in the model diatom Phaeodactylum tricornutum. Loss of KEA3 activity affects the PET/PMF coupling and NPQ responses at the onset of illumination, during transients and in steady-state conditions. Thus, this antiporter is a main regulator of the PET/PMF coupling. Consistent with this conclusion, a parsimonious model including only two free components, KEA3 and the diadinoxanthin de-epoxidase, describes most of the feedback loops between PET and NPQ. This simple regulatory system allows for efficient responses to fast (minutes) or slow (e.g. diel) changes in light environment, thanks to the presence of a regulatory calcium ion (Ca²⁺ )-binding domain in KEA3 modulating its activity. This circuit is likely tuned by the NPQ-effector proteins, LHCXs, providing diatoms with the required flexibility to thrive in different ocean provinces.

Impact of busulfan pharmacokinetics on outcome in adult patients receiving an allogeneic hematopoietic cell transplantation

Busulfan (Bu) is widely used in conditioning regimens before allogeneic hematopoietic cell transplantation, with variable metabolism due to interindividual differences of pharmacokinetics (PK). The purpose of this study was to correlate pharmacokinetics and clinical outcomes. Lower-AUC, in range-AUC and higher-AUC were defined as ±25% of the targeted Bu-AUC. In 2019, we changed Bu dosing from 4×/day (Bu-4) to 1×/day (Bu-1) for ease of application. AUC-target range was reached in 46% of patients; 40% were in low-AUC and 14% in high-AUC. Among all toxicities, viral and fungal infections were significantly more frequent in high-AUC compared with low-AUC (20% vs. 8%; p = 0.01 and 37% vs. 17%; p = 0.03). Bu-1 showed lower PK values (66% vs. 36% of Bu-4 in low-AUC; p < 0.01) and higher incidence of mucositis (p = 0.02). Long-term outcomes at 2 years showed a higher non-relapse mortality (NRM) (p < 0.01) and higher relative risk of death in the high-AUC group compared to the other groups. Cumulative incidence of relapse and acute/chronic GvHD were not significantly different. The optimal cut-off in Bu-AUC associated with low NRM was 969 µmol/l*min (ROC AUC 0.67, sensitivity 0.86 and specificity 0.47) for Bu-4. In conclusion, low-AUC BU-PK seems of benefit regarding NRM and survival.

Rapidly progressive heart failure after dual-chamber pacemaker implantation

Pacing-induced cardiomyopathy (PICM) consists of heart failure (HF) associated with a drop in the left ventricular ejection fraction (LVEF) in the setting of high-burden right ventricular pacing, with presentation that may range from subclinical to severe. Time to manifestation can go from weeks to years after device implantation. Treatment typically consists in an upgrade to a cardiac resynchronisation therapy (CRT) or His bundle pacing (HisP). Several risk factors for PICM have been described and should be considered before pacemaker (PM) implantation, as thorough patient selection for de novo CRT or HisP, may preclude its manifestation. We present the case of an 82-year-old patient presenting with acute congestive HF and new severely reduced LVEF, 30 days following dual chamber PM implantation for high-grade atrioventricular block. Treatment with HF medication and upgrade to a CRT permitted rapid resolution of the symptoms and normalisation of the LVEF at 1-month follow-up.

Busulfan-cyclophosphamide versus cyclophosphamide-busulfan as conditioning regimen before allogeneic hematopoietic cell transplantation: a prospective randomized trial

Busulfan and cyclophosphamide (BuCy) is a frequently used myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation (allo-HCT). Theoretical considerations and pharmacological data indicate that application of busulfan prior to subsequent cyclophosphamide (BuCy) may trigger liver toxicity. Reversing the order of application to cyclophosphamide-busulfan (CyBu) might be preferable, a hypothesis supported by animal data and retrospective studies. We performed a prospective randomized trial to determine impact of order of application of Bu and Cy before allo-HCT in 70 patients with hematological malignancy, 33 patients received BuCy and 37 CyBu for conditioning. In the short term, there were minimal differences in liver toxicity favoring CyBu over BuCy, significant only for alanine amino transferase at day 30 (p = 0.03). With longer follow-up at 4 years, non-relapse mortality (6% versus 27%, p = 0.05) was lower and survival (63% versus 43%, p = 0.06) was higher with CyBu compared to BuCy. Other outcomes, such as engraftment (p = 0.21), acute and chronic graft-versus-host disease (p = 0.40; 0.36), and relapse (p = 0.79), were similar in both groups. We prospectively show evidence that the order of application of Cy and Bu in myeloablative conditioning in allo-HCT patients has impact on outcome.

[Aldosterone receptor antagonists]

Mineralocorticoid signaling pathway plays a pivotal role in cardiovascular physiopathology. Evidences from clinical and experimental studies have linked mineralocorticoid hormones with cardiovascular morbiditiy and mortality. Thus, antagonist of the mineralocorticoid receptor (AMR) has reappeared. In addition, a novel mineralocorticoid receptor antagonist has been developped, named eplerenone, which lack the side effect of former ARMs as gynecomastia. Based on two studies named RALES et EPHESUS, guidelines of the european and american societies of cardiology recommend the use of ARMs as a treatment for cardiac failure NYHA III and IV, and post-infarct cardiac failure (ejection fraction < 40%).

Percutaneous closure of atrial septal defect type ostium secundum using the new Intrasept occluder: Initial experience

We report the first experience obtained with the new Intrasept device. We attempted to treat 35 patients with a mean age of 43 +/- 21 years. The mean size of the defect was 17/15 mm. It was successfully closed in 31 patients. In the remaining four the device could not be stabilized because of excessive defect size. A small residual shunt was present immediately following implantation in three patients. No complications occurred during the procedure and at 6 months, 31 patients had an uneventful outcome. Only one patient had a small residual shunt. No thrombus, embolization, or device fracture was documented during a mean follow-up of 17 +/- 11 months. Percutaneous closure of ASD ostium secundum is feasible with the Intrasept device with a high success rate and very good medium-term outcome. Our initial experience and results were excellent with small to medium size defects, however, large defects (>20 mm) remain challenging.

[Surgical options for terminal heart failure]

Terminal heart failure can be the cause or the result of major dysfunctions of the organisms. Although, the outcome of the natural history is the same in both situations, it is of prime importance to differentiate the two, as only heart failure as the primary cause allows for successful mechanical circulatory support as bridge to transplantation or towards recovery. Various objective parameters allow for the establishment of the diagnosis of terminal heart failure despite optimal medical treatment. A cardiac index <2.0 l/min, and a mixed venous oxygen saturation <60%, in combination with progressive renal failure, should trigger a diagnostic work-up in order to identify cardiac defects that can be corrected or to list the patient for transplantation with/without mechanical circulatory support.

Treatment of Cytomegalovirus Infection or Disease in Solid Organ Transplant Recipients With Valganciclovir

Valganciclovir (VGC) has proved efficacious and safe for the prophylaxis against cytomegalovirus (CMV) in high-risk transplant recipients and for the treatment of CMV retinitis in AIDS patients. We used VGC for the treatment of CMV infection (viremia without symptoms) or disease (CMV syndrome or tissue-invasive disease) in kidney, heart, and lung transplant recipients. Fourteen transplant recipients were treated: five for asymptomatic CMV infection and nine for CMV disease. VGC was administered in doses adjusted to renal function for 4 to 12 weeks (induction and maintenance therapy). Clinically, all nine patients with CMV disease responded to treatment. Microbiologically, treatment with VGC turned blood culture negative for CMV within 2 weeks in all patients and was associated with a > or =2 log decrease in blood CMV DNA within 3 weeks in 8 of 8 tested patients. With a follow-up of 6 months (n = 12 patients), asymptomatic recurrent CMV viremia was noted in five cases, and CMV syndrome noted in one case (all cases in the first 2 months after the end of treatment). VGC was clinically well tolerated in all patients; however, laboratory abnormalities occurred in three cases (mild increase in transaminases, thrombocytopenia, and pancytopenia). This preliminary experience strongly suggests that therapy with VGC is effective against CMV in organ transplant recipients; however, the exact duration of therapy remains to be determined: a longer course may be necessary to prevent early recurrence.

[Percutaneous closure of patent foramen ovale: preliminary experience with the PFO Star]

This article reports the experience of percutaneous closure of patent foramen ovale with the PFO Star device. Between January 2000 and December 2002, 44 consecutive patients with a mean age of 53 years were included in this registry. The implantation of the prosthesis was successful in 43 patients (98%): in 1 patient the atrial septum could not be crossed at operation. An early complication was observed in 3 patients (7%): one had transient amnesia and two patients had temporary ST elevation in the inferior ECG leads. Four patients (7%) had late complications: there was one case of spontaneously regressive atrial fibrillation, two recurrences of stroke (one in the patient without an implanted prosthesis and the other in a patient in whom the patent foramen ovale had been closed). Finally, one patient developed a fistula between the aorta and right atrium which occluded spontaneously when the anticoagulants were stopped. Complete closure of the patent foramen ovale was confirmed at 1 year in 92% of patients. The authors conclude that this preliminary experience shows that closure of patent foramen ovale with this device is effective and safe.

[The heart transplant in Lausanne from 1987 to 2003]

Since the availability of ciclosporine, the survival after heart transplantation has dramatically improved. We present our results since the beginning of our experience in 1987. We treated in the Lausanne University hospital, 150 patients for end-stage cardiac disease. Hundred and fifty-two transplantations were performed. The survival rate is comparable to the literature with 81% at one year, 70% at five year and 63 at ten year included the hospital mortality. We review the incidence of complications during the follow-up and report the modification in the management of these patients especially concerning the immunosuppression.

Intravenous pamidronate as treatment for osteoporosis after heart transplantation: a prospective study

Fractures due to osteoporosis are one of the major complications after heart transplantation, occurring mostly during the first 6 months after the graft, with an incidence ranging from 18% to 50% for vertebral fractures. Bone mineral density (BMD) decreases dramatically following the graft, at trabecular sites as well as cortical sites. This is explained by the relatively high doses of glucocorticoids used during the months following the graft, and by a long-term increase of bone turnover which is probably due to cyclosporine. There is some evidence for a beneficial effect on BMD of antiresorptive treatments after heart transplantation. The aim of this study was to assess prospectively the effect on BMD of a 3-year treatment of quarterly infusions of 60 mg of pamidronate, combined with 1 g calcium and 1000 U vitamin D per day, in osteoporotic heart transplant recipients, and that of a treatment with calcium and vitamin D in heart transplant recipients with no osteoporosis. BMD of the lumbar spine and the femoral neck was measured by dual-energy X-ray absorptiometry in all patients every 6 months for 2 years and after 3 years. Seventeen patients, (1 woman, 16 men) aged 46+/-4 years (mean +/- SEM) received only calcium and vitamin D. A significant decrease in BMD was observed after 6 months following the graft, at the lumbar spine (- 6.6%) as well as at the femoral neck (-7.8%). After 2 years, BMD tended to recover at the lumbar spine, whereas the loss persisted after 3 years at the femoral neck. Eleven patients (1 woman and 10 men) aged 46+/-4 years (mean +/- SEM) started treatment with pamidronate on average 6 months after the graft, because they had osteoporosis of the lumbar spine and/or femoral neck (BMD T-score below -2.5 SD). Over the whole treatment period, a continuous increase in BMD at the lumbar spine was noticed, reaching 18.3% after 3 years (14.3% compared with the BMD at the time of the graft). BMD at the femoral neck was lowered in the first year by -3.4%, but recovered totally after 3 years of treatment. In conclusion, a 3-year study of treatment with pamidronate given every 3 months to patients with existing osteoporosis led to a significant increase in lumbar spine BMD and prevented loss at the femoral neck. However, since some of these patients were treated up to 14 months after the transplant, they may already have passed through the phase of most rapid bone loss. In patients who were not osteoporotic at baseline, treatment with calcium and vitamin D alone was not able to prevent the rapid bone loss that occurs immediately after transplantation.

Preemptive treatment approach to cytomegalovirus (CMV) infection in solid organ transplant patients: relationship between compliance with the guidelines and prevention of CMV morbidity

Cytomegalovirus (CMV) remains a major cause of morbidity in solid organ transplant patients. In order to reduce CMV morbidity, we designed a program of routine virological monitoring that included throat and urine CMV shell vial culture, along with peripheral blood leukocyte (PBL) shell vial quantitative culture for 12 weeks post-transplantation, as well as 8 weeks after treatment for acute rejection. The program also included preemptive ganciclovir treatment for those patients with the highest risk of developing CMV disease, i.e., with either high-level viremia (>10 infectious units [IU]/106 PBL) or low-level viremia (<10 IU/106 PBL) and either D+/R- CMV serostatus or treatment for graft rejection. During 1995-96, 90 solid organ transplant recipients (39 kidneys, 28 livers, and 23 hearts) were followed up. A total of 60 CMV infection episodes occurred in 45 patients. Seventeen episodes were symptomatic. Of 26 episodes managed according to the program, only 4 presented with CMV disease and none died. No patient treated preemptively for asymptomatic infection developed disease. In contrast, among 21 episodes managed in non-compliance with the program (i.e., the monitoring was not performed or preemptive treatment was not initiated despite a high risk of developing CMV disease), 12 episodes turned into symptomatic infection (P=0.0048 compared to patients treated preemptively), and 2 deaths possibly related to CMV were recorded. This difference could not be explained by an increased proportion of D+/R- patients or an increased incidence of rejection among patients with episodes treated in non-compliance with the program. Our data identify compliance with guidelines as an important factor in effectively reducing CMV morbidity through preemptive treatment, and suggest that the complexity of the preemptive approach may represent an important obstacle to the successful prevention of CMV morbidity by this approach in the regular healthcare setting.

Renal function one year after switching from Sandimmun to Neoral

BACKGROUND

The replacement of Sandimmun by Neoral in 1995 was thought to cause subsequent renal function deterioration due to the better bioavailability of the new drug. We prospectively analyzed the effect of a dose-to-dose drug replacement on renal function over 12 months.

METHODS AND RESULTS

The renal function of 47 consecutive heart transplanted patients was prospectively evaluated before (T0), at 1 (T1), 3 (T3), and 12 (T12) months after drug replacement. Mean serum creatinine was not significantly different at T0 and T12 (142 +/- 55 and 154 +/- 60 micromol/L, p = 0.1). We were able to reduce cyclosporine total and weight-indexed doses by, respectively, 11% and 14% between T0 and T12 (274 +/- 86 to 244 +/- 72 mg/d, p = 0.0003; and 3.7 +/- 1.4 to 3.2 +/- 1.2 mg/kg/d, respectively, p = 0.0005).

CONCLUSIONS

This study demonstrates that the dose-to-dose replacement of Sandimmun by Neoral is feasible, with no direct influence on renal function over a 1-yr follow-up.

Extramediastinal surgical problems in heart transplant recipients

BACKGROUND

As heart transplantation has gained wide acceptance, a growing number of recipients are at risk of experiencing extramediastinal surgical problems.

STUDY DESIGN

We retrospectively reviewed our experience in the diagnosis and management of surgical problems occurring in 94 consecutive patients having heart transplantation. During the period of the study, we progressively adopted a policy of low-level immunosuppression, aiming toward monotherapy with cyclosporine.

RESULTS

Seventy-four extramediastinal surgical problems developed in 44 of 94 patients (47%). The type of problems were gastrointestinal in 17 of 74 (23%), vascular in 13 of 74 (17.5%), urogenital in 8 of 74 (11%), and neurologic in 4 of 74 (5.5%). There were also 9 of 74 cases of trauma (12%), 9 of 74 skin tumors (12%), and 14 of 74 miscellaneous diseases (19%). Sixty-two surgical diseases occurring in 40 patients required 75 surgical interventions, 11 of them (15%) on an emergency basis. Operations were performed for 12 of 74 neoplasms (16%) and 12 of 74 infectious or potentially infectious diseases (16%). Surgical diseases occurred most commonly within the first 6 months after transplantation (20 of 74; 27%). Complications occurred in 8 of 75 surgical interventions (9%). A high proportion of surgical disease was potentially related to immunosuppressive therapy (37 of 74; 50%) or to transplantation itself (7 of 74; 9%).

CONCLUSIONS

Extramediastinal diseases after heart transplantation involve most surgical specialties. Most of them are potentially linked with either the immunosuppressive therapy or the transplantation procedure, supporting our low-level immunosuppression policy. Expectant management is not justified in this population, who withstands operations well both early and late after transplantation.

Gastrointestinal disease following heart transplantation

With advances in heart transplantation, a growing number of recipients are at risk of developing gastrointestinal disease. We reviewed our experience with gastrointestinal disease in 92 patients undergoing 93 heart transplants. All had follow-up, with the median time 4.8 years (range 0.5-9.6 years). During the period of the study we progressively adopted a policy of low immunosuppression aiming toward monotherapy with cyclosporine. Nineteen patients (20.6%) developed 28 diseases related to the gastrointestinal tract. Thirteen patients required 18 surgical interventions, five as emergencies: closure of a duodenal ulcer, five cholecystectomies (one with biliary tract drainage), a sigmoid resection for a diverticulitis with a colovesical fistula, a colostomy followed by a colostomy takedown for an iatrogenic colon perforation, appendectomy, two anorectal procedures, and six abdominal wall herniorrhaphies. At the onset of gastrointestinal disease, 8 patients were on standard triple-drug immunosuppression, all of them within 6 months of transplantation; 13 were on double-drug immunosuppression; and 7 were on cyclosporine alone. All the patients with perforations/fistulas were on steroids. Among the 11 infectious or potentially infectious diseases, 10 were on triple- or double-drug immunosuppression. One death, a patient who was on triple-drug immunosuppression, had a postmortem diagnosis of necrotic and hemorrhagic pancreatitis. Except for an incisional hernia following a laparoscopic cholecystectomy, there was no morbidity and, importantly, no septic complications. We concluded that a low immunosuppression policy is likely to be responsible for the low morbidity and mortality of posttransplant gastrointestinal disease, with a lower incidence of viscous perforation/fistula and infectious gastrointestinal disease.

Incidence and prognostic value of electrocardiographic abnormalities after heart transplantation

BACKGROUND

The improvement of surgical techniques and the use of immunosuppressive drugs within the past 15 years has made heart transplantation an increasingly performed procedure and an accepted treatment for end-stage cardiac failure.

HYPOTHESIS

The aim of this study was to describe the changes of the 12-lead electrocardiogram (ECG) after heart transplantation and to determine their prognostic value on complications such as rejection or graft coronary artery disease during follow-up.

METHODS

The ECGs of 62 consecutive patients were analyzed for 5 years at follow-up periods of 1, 2, 3, 6 months and yearly after transplantation.

RESULTS

The most prevalent abnormality was the presence of complete or incomplete right bundle-branch block (RBBB). New RBBB appeared in 69% (43/62) of the patients, mainly during the first month (21/43). There was no left bundle-branch block. We detected nine episodes of supraventricular arrhythmias: one atrial fibrillation, six atrial flutter, one junctional tachycardia, one orthodromic tachycardia on a Wolff-Parkinson-White syndrome; all appearing during the first 3 months. Three of the six episodes of atrial flutter occurred during an episode of acute rejection. There was no relation between RBBB and the gender and age of recipients and donors, nor with the graft ischemic time and the pretransplantation hemodynamic values. Right bundle-branch block was not associated with acute rejection nor with graft coronary artery disease.

CONCLUSION

The ECG abnormalities after heart transplantation have no predictive value on the long-term evolution. Right bundle-branch block is very frequent and is not associated with adverse prognosis.

Uricosuric effect of the angiotensin II receptor antagonist losartan in heart transplant recipients

BACKGROUND

The angiotensin II receptor antagonist losartan is an effective antihypertensive agent with unique uricosuric properties. This study evaluates the uricosuric effects of losartan in 10 hypertensive heart transplant patients with hyperuricemia.

METHODS

The patients were randomized to receive losartan 50 mg once daily and enalapril 20 mg once daily for 4 weeks according to a double-blind crossover design. Office blood pressure, plasma uric acid levels, and urinary uric acid excretion were monitored throughout the study.

RESULTS

Plasma uric acid levels decreased significantly after 4 weeks of treatment with losartan (P<0.05) but not with enalapril. On day 1 and after 1 month of treatment, a significant increase in uric acid excretion was observed only with losartan. Significant decreases in office systolic and diastolic blood pressures were obtained with enalapril but not with losartan.

CONCLUSIONS

Losartan effectively lowers plasma uric acid levels in hyperuricemic heart transplant patients.

Impairment of the myocardial vasomotor response to cold pressor stress in collateral dependent myocardium

OBJECTIVE

To study the vasomotor response (cold pressor/basal flow) in myocardium perfused entirely by collaterals, using the reflex sympathetic stimulation of cold pressor stress.

DESIGN

Regional myocardial blood flow was measured in collateral dependent and in remote myocardium using positron emission tomography with 15O water at basal and at cold pressor stress. Regional ischaemia was measured with 18F-fluorodeoxyglucose (FDG).

PATIENTS

Nine patients (mean (SD) age 53 (6) years) with an occluded coronary artery supplied entirely by collaterals from other angiographically normal arteries.

RESULTS

In remote myocardium, basal and cold pressor flow were 0.99 (0.26) and 1.46 (0.60) ml/min/g (P < 0.05), respectively, a myocardial vasomotor response of 1.46 (0.45). In collateral dependent myocardium, basal and cold pressor flow were 0.91 (0.20) and 0.87 (0.35) ml/min/g, respectively (the latter value, P < 0.05 v remote region), a myocardial vasomotor response of 0.97 (0.43) (P < 0.05 v remote region). The myocardial vascular resistance (mean arterial pressure/flow) during cold pressor was higher in the collateral dependent than in remote myocardium, at 147.0 (61.1) and 85.6 (32.3) mm Hg.min.g/ml (P < 0.05), respectively, but with no relative increase in FDG uptake.

CONCLUSIONS

In contrast to the decrease in myocardial resistance in remote myocardium with cold pressor, an increase was observed in collateral dependent myocardium suggesting a vasoconstrictor response in resistive vessels, without demonstrable myocardial ischaemia.

[Follow-up after heart transplantation]

The prognosis of patients with end-stage cardiac disease has dramatically changed with transplantation. The incidence of complications remains relatively high and needs a very careful follow-up to have good long term results.

[Heart-kidney transplantation of the same donor following failure of a first renal transplantation due to chronic rejection]

Combined heart and renal transplantation from the same donor is an uncommon procedure. We describe the case of a patient with prior kidney transplantation whose renal graft had to be removed a few years later because of chronic rejection. The patient then developed severe hypertensive and ischemic left ventricular dysfunction. Combined heart and kidney transplantation was performed several years after the first renal transplantation. This observation is the first description of a combined heart and kidney transplantation after removal of a former renal graft whose failure was due to chronic rejection. Great care was taken to avoid identical MHC antigens (HLA-A; -B; -DR) between the two donors, to prevent recurrent rejection of the grafted organs. After 18 months, no rejection was detected in either organ. This case report confirms the feasibility of this complex procedure, provided care is taken to avoid identical HLA groups between the two donors so as to reduce immunological complications.

Placement of multiple and different stent types for very long dissections during coronary angioplasty

We have been investigating the safety and efficacy of multiple and different stent types placed in the unfavorable situation of a very long dissection (> 20 mm) after coronary angioplasty. We report our preliminary experience in 20 patients who were treated by the following combinations: Palmaz-Schatz and Micro stent (14 patients). Wallstent and Micro stent (4 patients); Wiktor and Micro stent (1 patient); and Palmaz-Schatz, Micro and Wallstent (1 patient). Normal distal flow was restored in all except one (no reflow phenomenon) patient and complete covering of the dissection was obtained in all but two patients. Event-free survival at 30 days was 90% (18 of 20 patients). During follow-up (mean period: 8 +/- 3 months), two patients died. Of the 18 other patients, 16 remained asymptomatic and free of complications. Symptomatic restenosis was treated by standard angioplasty in the two remaining patients. In conclusion, placement of different stent types seems a feasible, safe, and efficient treatment for very long dissections caused by standard angioplasty.

Coronary stenting for coronary artery narrowing in a heart transplant recipient

Transplant atherosclerotic coronary disease remains the leading cause of death in heart transplant recipients. We report the first case of coronary stent implantation in a heart graft for epicardial focal stenosis. Due to the lower rate of restenosis after stenting in the native coronary artery, we suggest that coronary stenting be considered an acceptable, first intention therapeutic option instead of angioplasty alone whenever possible.

[Patient management following cardiac transplantation]

Prognosis of heart transplant patients has dramatically improved in the last decade thanks to the use of cyclosporine as immunosuppressive treatment. Optimal follow-up and early recognition of complications and side effects of treatment lead to longer survival and marked improvement of these patients' quality of life. However, the incidence of complications remains high and their management calls for particular care. We review our experience of heart transplantation in Lausanne and describe in detail the results and complications such as rejection, transplant coronary artery disease, hypertension, renal failure, metabolic disorders, cancer and conduction problems. Cooperation of the medical team (cardiologist, surgeon, anesthetist, general practitioner) is essential to long term success of the transplant program.

Effect of intravenous calcitonin gene related peptide on ischaemia threshold and coronary stenosis severity in humans

OBJECTIVE

Calcitonin gene related peptide (CGRP) is a potent vasodilator found in sensory nerve endings in coronary arteries. The effect of intravenous CGRP on myocardial ischaemia, cardiovascular haemodynamics, and epicardial coronary artery stenoses was studied in patients with angina to investigate the possible role of CGRP in the control of vasodilation in the coronary circulation.

METHODS

12 patients (mean age 60 years) performed exercise tests on consecutive days during intravenous infusions of placebo or CGRP (at 50 pmol.min-1). At cardiac catheterisation (6 patients), consecutive 20 min intravenous infusions of placebo and CGRP were given at a fixed heart rate, with measurement of haemodynamic variables and quantitative arteriography.

RESULTS

The time to 0.1 mV ST depression increased from 475(SD 245) to 546(193) s (p < 0.05), and time to 0.2 mV ST segment depression, from 634(266) to 694(202) s (p < 0.05), on placebo and CGRP respectively. Rate-pressure product at 0.1 mV ST segment depression was 18,410(4590) and 20,750(7270) mm Hg.min-1 (p < 0.05), and at 0.2 mV ST depression it was 21,510(6470) and 24,080(7380) mm Hg.min-1 (p < 0.01), with placebo and CGRP, respectively. At catheterisation, diastolic blood pressure fell from 93(11) to 83(8) mm Hg (p < 0.05), systemic vascular resistance fell from 26.2(9.4) to 20.7(9.0) units (p < 0.05), and cardiac output increased from 5.94(1.10) to 6.73(1.04) litre.min-1 (p < 0.05), on placebo and CGRP respectively. Minimum luminal diameter increased from 0.66(0.23) to 1.11(0.15) mm (p < 0.01) with CGRP.

CONCLUSIONS

Intravenous CGRP is a systemic arterial vasodilator which dilates coronary arteries at the site of atheromatous stenoses and delays the onset of myocardial ischaemia during treadmill exercise testing in patients with chronic stable angina.

Bacterial brain abscesses: factors influencing mortality and sequelae

Thirty-nine cases of brain abscess diagnosed since the advent of the computed tomographic (CT) scan were analyzed for factors influencing the outcome. The mortality rate was 13%, and severe sequelae were present in 22% of the survivors. The mean delay between occurrence of the first symptoms and hospitalization was significantly shorter for the 12 patients with poor outcome (death or severe sequelae) than for the 25 who recovered (fully or with moderate sequelae). Moreover, severely impaired mental status and neurological impairment at admission were associated with a poor outcome in terms of both mortality and sequelae. In all cases with fatal outcome or severe sequelae, the diagnosis was made and treatment was initiated within 24 hours of admission. There was no apparent correlation between the outcome and the presence or type of predisposing factors, the radiological, biological, or microbiological findings, or the treatment modalities. Thus, with the advent of the CT scan and the possibility of early diagnosis and treatment, the prognosis of brain abscess appears to be mainly determined by the rapidity of progression of the disease before hospitalization and the patient's mental status on admission.

Evidence for pancreas injury in adult respiratory distress syndrome

The purpose of this study was to investigate the relation between serum lipase (LP), serum immunoreactive trypsin (IRT), and its inhibitors in patients with adult respiratory distress syndrome (ARDS) of diverse origin and to compare their time course with other acute conditions. The IRT and LP levels were determined at regular intervals in 41 patients hospitalized in the intensive respiratory unit with ARDS (n = 9), acute pancreatitis (n = 5), shock (n = 9), bronchopneumonia (n = 10), or acute cardiogenic pulmonary edema (n = 8). Several trypsin inhibitors were measured simultaneously: serum trypsin inhibitory capacity (TIC), alpha 1-antitrypsin, alpha 2-macroglobulin, and antithrombin III. Concomitantly, angiotensin-converting enzyme (ACE) activity was determined as a potential marker of the endothelial injury. A respective 19- and 13-fold increase in IRT and LP values were observed in patients with ARDS after a mean evolution of 6 days; similar increases were seen in patients with pancreatitis. These values were significantly higher than those observed in the other conditions studied. In patients with ARDS and acute pancreatitis, the evolution of IRT and LP values were associated with a sixfold rise in TIC. A low TIC/IRT ratio in patients with ARDS appeared to be an index of poor prognosis. Conversely, ACE activity evolution was characterized by an early decrease in all the conditions studied. These observations indicate that there is an acute delayed pancreas injury in ARDS. Thus, the release of pancreatic enzymes are not reliable markers of the early evolution of the disease but they may represent secondary mediators for enhancement of the increased endothelial permeability.